1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * This file is part of STM32 ADC driver
4 *
5 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
6 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
7 */
8
9 #include <linux/clk.h>
10 #include <linux/delay.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/dmaengine.h>
13 #include <linux/iio/iio.h>
14 #include <linux/iio/buffer.h>
15 #include <linux/iio/timer/stm32-lptim-trigger.h>
16 #include <linux/iio/timer/stm32-timer-trigger.h>
17 #include <linux/iio/trigger.h>
18 #include <linux/iio/trigger_consumer.h>
19 #include <linux/iio/triggered_buffer.h>
20 #include <linux/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/iopoll.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/of.h>
27 #include <linux/of_device.h>
28
29 #include "stm32-adc-core.h"
30
31 /* Number of linear calibration shadow registers / LINCALRDYW control bits */
32 #define STM32H7_LINCALFACT_NUM 6
33
34 /* BOOST bit must be set on STM32H7 when ADC clock is above 20MHz */
35 #define STM32H7_BOOST_CLKRATE 20000000UL
36
37 #define STM32_ADC_CH_MAX 20 /* max number of channels */
38 #define STM32_ADC_CH_SZ 10 /* max channel name size */
39 #define STM32_ADC_MAX_SQ 16 /* SQ1..SQ16 */
40 #define STM32_ADC_MAX_SMP 7 /* SMPx range is [0..7] */
41 #define STM32_ADC_TIMEOUT_US 100000
42 #define STM32_ADC_TIMEOUT (msecs_to_jiffies(STM32_ADC_TIMEOUT_US / 1000))
43 #define STM32_ADC_HW_STOP_DELAY_MS 100
44
45 #define STM32_DMA_BUFFER_SIZE PAGE_SIZE
46
47 /* External trigger enable */
48 enum stm32_adc_exten {
49 STM32_EXTEN_SWTRIG,
50 STM32_EXTEN_HWTRIG_RISING_EDGE,
51 STM32_EXTEN_HWTRIG_FALLING_EDGE,
52 STM32_EXTEN_HWTRIG_BOTH_EDGES,
53 };
54
55 /* extsel - trigger mux selection value */
56 enum stm32_adc_extsel {
57 STM32_EXT0,
58 STM32_EXT1,
59 STM32_EXT2,
60 STM32_EXT3,
61 STM32_EXT4,
62 STM32_EXT5,
63 STM32_EXT6,
64 STM32_EXT7,
65 STM32_EXT8,
66 STM32_EXT9,
67 STM32_EXT10,
68 STM32_EXT11,
69 STM32_EXT12,
70 STM32_EXT13,
71 STM32_EXT14,
72 STM32_EXT15,
73 STM32_EXT16,
74 STM32_EXT17,
75 STM32_EXT18,
76 STM32_EXT19,
77 STM32_EXT20,
78 };
79
80 /**
81 * struct stm32_adc_trig_info - ADC trigger info
82 * @name: name of the trigger, corresponding to its source
83 * @extsel: trigger selection
84 */
85 struct stm32_adc_trig_info {
86 const char *name;
87 enum stm32_adc_extsel extsel;
88 };
89
90 /**
91 * struct stm32_adc_calib - optional adc calibration data
92 * @calfact_s: Calibration offset for single ended channels
93 * @calfact_d: Calibration offset in differential
94 * @lincalfact: Linearity calibration factor
95 * @calibrated: Indicates calibration status
96 */
97 struct stm32_adc_calib {
98 u32 calfact_s;
99 u32 calfact_d;
100 u32 lincalfact[STM32H7_LINCALFACT_NUM];
101 bool calibrated;
102 };
103
104 /**
105 * struct stm32_adc_regs - stm32 ADC misc registers & bitfield desc
106 * @reg: register offset
107 * @mask: bitfield mask
108 * @shift: left shift
109 */
110 struct stm32_adc_regs {
111 int reg;
112 int mask;
113 int shift;
114 };
115
116 /**
117 * struct stm32_adc_regspec - stm32 registers definition
118 * @dr: data register offset
119 * @ier_eoc: interrupt enable register & eocie bitfield
120 * @ier_ovr: interrupt enable register & overrun bitfield
121 * @isr_eoc: interrupt status register & eoc bitfield
122 * @isr_ovr: interrupt status register & overrun bitfield
123 * @sqr: reference to sequence registers array
124 * @exten: trigger control register & bitfield
125 * @extsel: trigger selection register & bitfield
126 * @res: resolution selection register & bitfield
127 * @smpr: smpr1 & smpr2 registers offset array
128 * @smp_bits: smpr1 & smpr2 index and bitfields
129 */
130 struct stm32_adc_regspec {
131 const u32 dr;
132 const struct stm32_adc_regs ier_eoc;
133 const struct stm32_adc_regs ier_ovr;
134 const struct stm32_adc_regs isr_eoc;
135 const struct stm32_adc_regs isr_ovr;
136 const struct stm32_adc_regs *sqr;
137 const struct stm32_adc_regs exten;
138 const struct stm32_adc_regs extsel;
139 const struct stm32_adc_regs res;
140 const u32 smpr[2];
141 const struct stm32_adc_regs *smp_bits;
142 };
143
144 struct stm32_adc;
145
146 /**
147 * struct stm32_adc_cfg - stm32 compatible configuration data
148 * @regs: registers descriptions
149 * @adc_info: per instance input channels definitions
150 * @trigs: external trigger sources
151 * @clk_required: clock is required
152 * @has_vregready: vregready status flag presence
153 * @prepare: optional prepare routine (power-up, enable)
154 * @start_conv: routine to start conversions
155 * @stop_conv: routine to stop conversions
156 * @unprepare: optional unprepare routine (disable, power-down)
157 * @irq_clear: routine to clear irqs
158 * @smp_cycles: programmable sampling time (ADC clock cycles)
159 */
160 struct stm32_adc_cfg {
161 const struct stm32_adc_regspec *regs;
162 const struct stm32_adc_info *adc_info;
163 struct stm32_adc_trig_info *trigs;
164 bool clk_required;
165 bool has_vregready;
166 int (*prepare)(struct iio_dev *);
167 void (*start_conv)(struct iio_dev *, bool dma);
168 void (*stop_conv)(struct iio_dev *);
169 void (*unprepare)(struct iio_dev *);
170 void (*irq_clear)(struct iio_dev *indio_dev, u32 msk);
171 const unsigned int *smp_cycles;
172 };
173
174 /**
175 * struct stm32_adc - private data of each ADC IIO instance
176 * @common: reference to ADC block common data
177 * @offset: ADC instance register offset in ADC block
178 * @cfg: compatible configuration data
179 * @completion: end of single conversion completion
180 * @buffer: data buffer + 8 bytes for timestamp if enabled
181 * @clk: clock for this adc instance
182 * @irq: interrupt for this adc instance
183 * @lock: spinlock
184 * @bufi: data buffer index
185 * @num_conv: expected number of scan conversions
186 * @res: data resolution (e.g. RES bitfield value)
187 * @trigger_polarity: external trigger polarity (e.g. exten)
188 * @dma_chan: dma channel
189 * @rx_buf: dma rx buffer cpu address
190 * @rx_dma_buf: dma rx buffer bus address
191 * @rx_buf_sz: dma rx buffer size
192 * @difsel: bitmask to set single-ended/differential channel
193 * @pcsel: bitmask to preselect channels on some devices
194 * @smpr_val: sampling time settings (e.g. smpr1 / smpr2)
195 * @cal: optional calibration data on some devices
196 * @chan_name: channel name array
197 */
198 struct stm32_adc {
199 struct stm32_adc_common *common;
200 u32 offset;
201 const struct stm32_adc_cfg *cfg;
202 struct completion completion;
203 u16 buffer[STM32_ADC_MAX_SQ + 4] __aligned(8);
204 struct clk *clk;
205 int irq;
206 spinlock_t lock; /* interrupt lock */
207 unsigned int bufi;
208 unsigned int num_conv;
209 u32 res;
210 u32 trigger_polarity;
211 struct dma_chan *dma_chan;
212 u8 *rx_buf;
213 dma_addr_t rx_dma_buf;
214 unsigned int rx_buf_sz;
215 u32 difsel;
216 u32 pcsel;
217 u32 smpr_val[2];
218 struct stm32_adc_calib cal;
219 char chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
220 };
221
222 struct stm32_adc_diff_channel {
223 u32 vinp;
224 u32 vinn;
225 };
226
227 /**
228 * struct stm32_adc_info - stm32 ADC, per instance config data
229 * @max_channels: Number of channels
230 * @resolutions: available resolutions
231 * @num_res: number of available resolutions
232 */
233 struct stm32_adc_info {
234 int max_channels;
235 const unsigned int *resolutions;
236 const unsigned int num_res;
237 };
238
239 static const unsigned int stm32f4_adc_resolutions[] = {
240 /* sorted values so the index matches RES[1:0] in STM32F4_ADC_CR1 */
241 12, 10, 8, 6,
242 };
243
244 /* stm32f4 can have up to 16 channels */
245 static const struct stm32_adc_info stm32f4_adc_info = {
246 .max_channels = 16,
247 .resolutions = stm32f4_adc_resolutions,
248 .num_res = ARRAY_SIZE(stm32f4_adc_resolutions),
249 };
250
251 static const unsigned int stm32h7_adc_resolutions[] = {
252 /* sorted values so the index matches RES[2:0] in STM32H7_ADC_CFGR */
253 16, 14, 12, 10, 8,
254 };
255
256 /* stm32h7 can have up to 20 channels */
257 static const struct stm32_adc_info stm32h7_adc_info = {
258 .max_channels = STM32_ADC_CH_MAX,
259 .resolutions = stm32h7_adc_resolutions,
260 .num_res = ARRAY_SIZE(stm32h7_adc_resolutions),
261 };
262
263 /*
264 * stm32f4_sq - describe regular sequence registers
265 * - L: sequence len (register & bit field)
266 * - SQ1..SQ16: sequence entries (register & bit field)
267 */
268 static const struct stm32_adc_regs stm32f4_sq[STM32_ADC_MAX_SQ + 1] = {
269 /* L: len bit field description to be kept as first element */
270 { STM32F4_ADC_SQR1, GENMASK(23, 20), 20 },
271 /* SQ1..SQ16 registers & bit fields (reg, mask, shift) */
272 { STM32F4_ADC_SQR3, GENMASK(4, 0), 0 },
273 { STM32F4_ADC_SQR3, GENMASK(9, 5), 5 },
274 { STM32F4_ADC_SQR3, GENMASK(14, 10), 10 },
275 { STM32F4_ADC_SQR3, GENMASK(19, 15), 15 },
276 { STM32F4_ADC_SQR3, GENMASK(24, 20), 20 },
277 { STM32F4_ADC_SQR3, GENMASK(29, 25), 25 },
278 { STM32F4_ADC_SQR2, GENMASK(4, 0), 0 },
279 { STM32F4_ADC_SQR2, GENMASK(9, 5), 5 },
280 { STM32F4_ADC_SQR2, GENMASK(14, 10), 10 },
281 { STM32F4_ADC_SQR2, GENMASK(19, 15), 15 },
282 { STM32F4_ADC_SQR2, GENMASK(24, 20), 20 },
283 { STM32F4_ADC_SQR2, GENMASK(29, 25), 25 },
284 { STM32F4_ADC_SQR1, GENMASK(4, 0), 0 },
285 { STM32F4_ADC_SQR1, GENMASK(9, 5), 5 },
286 { STM32F4_ADC_SQR1, GENMASK(14, 10), 10 },
287 { STM32F4_ADC_SQR1, GENMASK(19, 15), 15 },
288 };
289
290 /* STM32F4 external trigger sources for all instances */
291 static struct stm32_adc_trig_info stm32f4_adc_trigs[] = {
292 { TIM1_CH1, STM32_EXT0 },
293 { TIM1_CH2, STM32_EXT1 },
294 { TIM1_CH3, STM32_EXT2 },
295 { TIM2_CH2, STM32_EXT3 },
296 { TIM2_CH3, STM32_EXT4 },
297 { TIM2_CH4, STM32_EXT5 },
298 { TIM2_TRGO, STM32_EXT6 },
299 { TIM3_CH1, STM32_EXT7 },
300 { TIM3_TRGO, STM32_EXT8 },
301 { TIM4_CH4, STM32_EXT9 },
302 { TIM5_CH1, STM32_EXT10 },
303 { TIM5_CH2, STM32_EXT11 },
304 { TIM5_CH3, STM32_EXT12 },
305 { TIM8_CH1, STM32_EXT13 },
306 { TIM8_TRGO, STM32_EXT14 },
307 {}, /* sentinel */
308 };
309
310 /*
311 * stm32f4_smp_bits[] - describe sampling time register index & bit fields
312 * Sorted so it can be indexed by channel number.
313 */
314 static const struct stm32_adc_regs stm32f4_smp_bits[] = {
315 /* STM32F4_ADC_SMPR2: smpr[] index, mask, shift for SMP0 to SMP9 */
316 { 1, GENMASK(2, 0), 0 },
317 { 1, GENMASK(5, 3), 3 },
318 { 1, GENMASK(8, 6), 6 },
319 { 1, GENMASK(11, 9), 9 },
320 { 1, GENMASK(14, 12), 12 },
321 { 1, GENMASK(17, 15), 15 },
322 { 1, GENMASK(20, 18), 18 },
323 { 1, GENMASK(23, 21), 21 },
324 { 1, GENMASK(26, 24), 24 },
325 { 1, GENMASK(29, 27), 27 },
326 /* STM32F4_ADC_SMPR1, smpr[] index, mask, shift for SMP10 to SMP18 */
327 { 0, GENMASK(2, 0), 0 },
328 { 0, GENMASK(5, 3), 3 },
329 { 0, GENMASK(8, 6), 6 },
330 { 0, GENMASK(11, 9), 9 },
331 { 0, GENMASK(14, 12), 12 },
332 { 0, GENMASK(17, 15), 15 },
333 { 0, GENMASK(20, 18), 18 },
334 { 0, GENMASK(23, 21), 21 },
335 { 0, GENMASK(26, 24), 24 },
336 };
337
338 /* STM32F4 programmable sampling time (ADC clock cycles) */
339 static const unsigned int stm32f4_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = {
340 3, 15, 28, 56, 84, 112, 144, 480,
341 };
342
343 static const struct stm32_adc_regspec stm32f4_adc_regspec = {
344 .dr = STM32F4_ADC_DR,
345 .ier_eoc = { STM32F4_ADC_CR1, STM32F4_EOCIE },
346 .ier_ovr = { STM32F4_ADC_CR1, STM32F4_OVRIE },
347 .isr_eoc = { STM32F4_ADC_SR, STM32F4_EOC },
348 .isr_ovr = { STM32F4_ADC_SR, STM32F4_OVR },
349 .sqr = stm32f4_sq,
350 .exten = { STM32F4_ADC_CR2, STM32F4_EXTEN_MASK, STM32F4_EXTEN_SHIFT },
351 .extsel = { STM32F4_ADC_CR2, STM32F4_EXTSEL_MASK,
352 STM32F4_EXTSEL_SHIFT },
353 .res = { STM32F4_ADC_CR1, STM32F4_RES_MASK, STM32F4_RES_SHIFT },
354 .smpr = { STM32F4_ADC_SMPR1, STM32F4_ADC_SMPR2 },
355 .smp_bits = stm32f4_smp_bits,
356 };
357
358 static const struct stm32_adc_regs stm32h7_sq[STM32_ADC_MAX_SQ + 1] = {
359 /* L: len bit field description to be kept as first element */
360 { STM32H7_ADC_SQR1, GENMASK(3, 0), 0 },
361 /* SQ1..SQ16 registers & bit fields (reg, mask, shift) */
362 { STM32H7_ADC_SQR1, GENMASK(10, 6), 6 },
363 { STM32H7_ADC_SQR1, GENMASK(16, 12), 12 },
364 { STM32H7_ADC_SQR1, GENMASK(22, 18), 18 },
365 { STM32H7_ADC_SQR1, GENMASK(28, 24), 24 },
366 { STM32H7_ADC_SQR2, GENMASK(4, 0), 0 },
367 { STM32H7_ADC_SQR2, GENMASK(10, 6), 6 },
368 { STM32H7_ADC_SQR2, GENMASK(16, 12), 12 },
369 { STM32H7_ADC_SQR2, GENMASK(22, 18), 18 },
370 { STM32H7_ADC_SQR2, GENMASK(28, 24), 24 },
371 { STM32H7_ADC_SQR3, GENMASK(4, 0), 0 },
372 { STM32H7_ADC_SQR3, GENMASK(10, 6), 6 },
373 { STM32H7_ADC_SQR3, GENMASK(16, 12), 12 },
374 { STM32H7_ADC_SQR3, GENMASK(22, 18), 18 },
375 { STM32H7_ADC_SQR3, GENMASK(28, 24), 24 },
376 { STM32H7_ADC_SQR4, GENMASK(4, 0), 0 },
377 { STM32H7_ADC_SQR4, GENMASK(10, 6), 6 },
378 };
379
380 /* STM32H7 external trigger sources for all instances */
381 static struct stm32_adc_trig_info stm32h7_adc_trigs[] = {
382 { TIM1_CH1, STM32_EXT0 },
383 { TIM1_CH2, STM32_EXT1 },
384 { TIM1_CH3, STM32_EXT2 },
385 { TIM2_CH2, STM32_EXT3 },
386 { TIM3_TRGO, STM32_EXT4 },
387 { TIM4_CH4, STM32_EXT5 },
388 { TIM8_TRGO, STM32_EXT7 },
389 { TIM8_TRGO2, STM32_EXT8 },
390 { TIM1_TRGO, STM32_EXT9 },
391 { TIM1_TRGO2, STM32_EXT10 },
392 { TIM2_TRGO, STM32_EXT11 },
393 { TIM4_TRGO, STM32_EXT12 },
394 { TIM6_TRGO, STM32_EXT13 },
395 { TIM15_TRGO, STM32_EXT14 },
396 { TIM3_CH4, STM32_EXT15 },
397 { LPTIM1_OUT, STM32_EXT18 },
398 { LPTIM2_OUT, STM32_EXT19 },
399 { LPTIM3_OUT, STM32_EXT20 },
400 {},
401 };
402
403 /*
404 * stm32h7_smp_bits - describe sampling time register index & bit fields
405 * Sorted so it can be indexed by channel number.
406 */
407 static const struct stm32_adc_regs stm32h7_smp_bits[] = {
408 /* STM32H7_ADC_SMPR1, smpr[] index, mask, shift for SMP0 to SMP9 */
409 { 0, GENMASK(2, 0), 0 },
410 { 0, GENMASK(5, 3), 3 },
411 { 0, GENMASK(8, 6), 6 },
412 { 0, GENMASK(11, 9), 9 },
413 { 0, GENMASK(14, 12), 12 },
414 { 0, GENMASK(17, 15), 15 },
415 { 0, GENMASK(20, 18), 18 },
416 { 0, GENMASK(23, 21), 21 },
417 { 0, GENMASK(26, 24), 24 },
418 { 0, GENMASK(29, 27), 27 },
419 /* STM32H7_ADC_SMPR2, smpr[] index, mask, shift for SMP10 to SMP19 */
420 { 1, GENMASK(2, 0), 0 },
421 { 1, GENMASK(5, 3), 3 },
422 { 1, GENMASK(8, 6), 6 },
423 { 1, GENMASK(11, 9), 9 },
424 { 1, GENMASK(14, 12), 12 },
425 { 1, GENMASK(17, 15), 15 },
426 { 1, GENMASK(20, 18), 18 },
427 { 1, GENMASK(23, 21), 21 },
428 { 1, GENMASK(26, 24), 24 },
429 { 1, GENMASK(29, 27), 27 },
430 };
431
432 /* STM32H7 programmable sampling time (ADC clock cycles, rounded down) */
433 static const unsigned int stm32h7_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = {
434 1, 2, 8, 16, 32, 64, 387, 810,
435 };
436
437 static const struct stm32_adc_regspec stm32h7_adc_regspec = {
438 .dr = STM32H7_ADC_DR,
439 .ier_eoc = { STM32H7_ADC_IER, STM32H7_EOCIE },
440 .ier_ovr = { STM32H7_ADC_IER, STM32H7_OVRIE },
441 .isr_eoc = { STM32H7_ADC_ISR, STM32H7_EOC },
442 .isr_ovr = { STM32H7_ADC_ISR, STM32H7_OVR },
443 .sqr = stm32h7_sq,
444 .exten = { STM32H7_ADC_CFGR, STM32H7_EXTEN_MASK, STM32H7_EXTEN_SHIFT },
445 .extsel = { STM32H7_ADC_CFGR, STM32H7_EXTSEL_MASK,
446 STM32H7_EXTSEL_SHIFT },
447 .res = { STM32H7_ADC_CFGR, STM32H7_RES_MASK, STM32H7_RES_SHIFT },
448 .smpr = { STM32H7_ADC_SMPR1, STM32H7_ADC_SMPR2 },
449 .smp_bits = stm32h7_smp_bits,
450 };
451
452 /**
453 * STM32 ADC registers access routines
454 * @adc: stm32 adc instance
455 * @reg: reg offset in adc instance
456 *
457 * Note: All instances share same base, with 0x0, 0x100 or 0x200 offset resp.
458 * for adc1, adc2 and adc3.
459 */
stm32_adc_readl(struct stm32_adc * adc,u32 reg)460 static u32 stm32_adc_readl(struct stm32_adc *adc, u32 reg)
461 {
462 return readl_relaxed(adc->common->base + adc->offset + reg);
463 }
464
465 #define stm32_adc_readl_addr(addr) stm32_adc_readl(adc, addr)
466
467 #define stm32_adc_readl_poll_timeout(reg, val, cond, sleep_us, timeout_us) \
468 readx_poll_timeout(stm32_adc_readl_addr, reg, val, \
469 cond, sleep_us, timeout_us)
470
stm32_adc_readw(struct stm32_adc * adc,u32 reg)471 static u16 stm32_adc_readw(struct stm32_adc *adc, u32 reg)
472 {
473 return readw_relaxed(adc->common->base + adc->offset + reg);
474 }
475
stm32_adc_writel(struct stm32_adc * adc,u32 reg,u32 val)476 static void stm32_adc_writel(struct stm32_adc *adc, u32 reg, u32 val)
477 {
478 writel_relaxed(val, adc->common->base + adc->offset + reg);
479 }
480
stm32_adc_set_bits(struct stm32_adc * adc,u32 reg,u32 bits)481 static void stm32_adc_set_bits(struct stm32_adc *adc, u32 reg, u32 bits)
482 {
483 unsigned long flags;
484
485 spin_lock_irqsave(&adc->lock, flags);
486 stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) | bits);
487 spin_unlock_irqrestore(&adc->lock, flags);
488 }
489
stm32_adc_clr_bits(struct stm32_adc * adc,u32 reg,u32 bits)490 static void stm32_adc_clr_bits(struct stm32_adc *adc, u32 reg, u32 bits)
491 {
492 unsigned long flags;
493
494 spin_lock_irqsave(&adc->lock, flags);
495 stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) & ~bits);
496 spin_unlock_irqrestore(&adc->lock, flags);
497 }
498
499 /**
500 * stm32_adc_conv_irq_enable() - Enable end of conversion interrupt
501 * @adc: stm32 adc instance
502 */
stm32_adc_conv_irq_enable(struct stm32_adc * adc)503 static void stm32_adc_conv_irq_enable(struct stm32_adc *adc)
504 {
505 stm32_adc_set_bits(adc, adc->cfg->regs->ier_eoc.reg,
506 adc->cfg->regs->ier_eoc.mask);
507 };
508
509 /**
510 * stm32_adc_conv_irq_disable() - Disable end of conversion interrupt
511 * @adc: stm32 adc instance
512 */
stm32_adc_conv_irq_disable(struct stm32_adc * adc)513 static void stm32_adc_conv_irq_disable(struct stm32_adc *adc)
514 {
515 stm32_adc_clr_bits(adc, adc->cfg->regs->ier_eoc.reg,
516 adc->cfg->regs->ier_eoc.mask);
517 }
518
stm32_adc_ovr_irq_enable(struct stm32_adc * adc)519 static void stm32_adc_ovr_irq_enable(struct stm32_adc *adc)
520 {
521 stm32_adc_set_bits(adc, adc->cfg->regs->ier_ovr.reg,
522 adc->cfg->regs->ier_ovr.mask);
523 }
524
stm32_adc_ovr_irq_disable(struct stm32_adc * adc)525 static void stm32_adc_ovr_irq_disable(struct stm32_adc *adc)
526 {
527 stm32_adc_clr_bits(adc, adc->cfg->regs->ier_ovr.reg,
528 adc->cfg->regs->ier_ovr.mask);
529 }
530
stm32_adc_set_res(struct stm32_adc * adc)531 static void stm32_adc_set_res(struct stm32_adc *adc)
532 {
533 const struct stm32_adc_regs *res = &adc->cfg->regs->res;
534 u32 val;
535
536 val = stm32_adc_readl(adc, res->reg);
537 val = (val & ~res->mask) | (adc->res << res->shift);
538 stm32_adc_writel(adc, res->reg, val);
539 }
540
stm32_adc_hw_stop(struct device * dev)541 static int stm32_adc_hw_stop(struct device *dev)
542 {
543 struct iio_dev *indio_dev = dev_get_drvdata(dev);
544 struct stm32_adc *adc = iio_priv(indio_dev);
545
546 if (adc->cfg->unprepare)
547 adc->cfg->unprepare(indio_dev);
548
549 clk_disable_unprepare(adc->clk);
550
551 return 0;
552 }
553
stm32_adc_hw_start(struct device * dev)554 static int stm32_adc_hw_start(struct device *dev)
555 {
556 struct iio_dev *indio_dev = dev_get_drvdata(dev);
557 struct stm32_adc *adc = iio_priv(indio_dev);
558 int ret;
559
560 ret = clk_prepare_enable(adc->clk);
561 if (ret)
562 return ret;
563
564 stm32_adc_set_res(adc);
565
566 if (adc->cfg->prepare) {
567 ret = adc->cfg->prepare(indio_dev);
568 if (ret)
569 goto err_clk_dis;
570 }
571
572 return 0;
573
574 err_clk_dis:
575 clk_disable_unprepare(adc->clk);
576
577 return ret;
578 }
579
580 /**
581 * stm32f4_adc_start_conv() - Start conversions for regular channels.
582 * @indio_dev: IIO device instance
583 * @dma: use dma to transfer conversion result
584 *
585 * Start conversions for regular channels.
586 * Also take care of normal or DMA mode. Circular DMA may be used for regular
587 * conversions, in IIO buffer modes. Otherwise, use ADC interrupt with direct
588 * DR read instead (e.g. read_raw, or triggered buffer mode without DMA).
589 */
stm32f4_adc_start_conv(struct iio_dev * indio_dev,bool dma)590 static void stm32f4_adc_start_conv(struct iio_dev *indio_dev, bool dma)
591 {
592 struct stm32_adc *adc = iio_priv(indio_dev);
593
594 stm32_adc_set_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN);
595
596 if (dma)
597 stm32_adc_set_bits(adc, STM32F4_ADC_CR2,
598 STM32F4_DMA | STM32F4_DDS);
599
600 stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_EOCS | STM32F4_ADON);
601
602 /* Wait for Power-up time (tSTAB from datasheet) */
603 usleep_range(2, 3);
604
605 /* Software start ? (e.g. trigger detection disabled ?) */
606 if (!(stm32_adc_readl(adc, STM32F4_ADC_CR2) & STM32F4_EXTEN_MASK))
607 stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_SWSTART);
608 }
609
stm32f4_adc_stop_conv(struct iio_dev * indio_dev)610 static void stm32f4_adc_stop_conv(struct iio_dev *indio_dev)
611 {
612 struct stm32_adc *adc = iio_priv(indio_dev);
613
614 stm32_adc_clr_bits(adc, STM32F4_ADC_CR2, STM32F4_EXTEN_MASK);
615 stm32_adc_clr_bits(adc, STM32F4_ADC_SR, STM32F4_STRT);
616
617 stm32_adc_clr_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN);
618 stm32_adc_clr_bits(adc, STM32F4_ADC_CR2,
619 STM32F4_ADON | STM32F4_DMA | STM32F4_DDS);
620 }
621
stm32f4_adc_irq_clear(struct iio_dev * indio_dev,u32 msk)622 static void stm32f4_adc_irq_clear(struct iio_dev *indio_dev, u32 msk)
623 {
624 struct stm32_adc *adc = iio_priv(indio_dev);
625
626 stm32_adc_clr_bits(adc, adc->cfg->regs->isr_eoc.reg, msk);
627 }
628
stm32h7_adc_start_conv(struct iio_dev * indio_dev,bool dma)629 static void stm32h7_adc_start_conv(struct iio_dev *indio_dev, bool dma)
630 {
631 struct stm32_adc *adc = iio_priv(indio_dev);
632 enum stm32h7_adc_dmngt dmngt;
633 unsigned long flags;
634 u32 val;
635
636 if (dma)
637 dmngt = STM32H7_DMNGT_DMA_CIRC;
638 else
639 dmngt = STM32H7_DMNGT_DR_ONLY;
640
641 spin_lock_irqsave(&adc->lock, flags);
642 val = stm32_adc_readl(adc, STM32H7_ADC_CFGR);
643 val = (val & ~STM32H7_DMNGT_MASK) | (dmngt << STM32H7_DMNGT_SHIFT);
644 stm32_adc_writel(adc, STM32H7_ADC_CFGR, val);
645 spin_unlock_irqrestore(&adc->lock, flags);
646
647 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTART);
648 }
649
stm32h7_adc_stop_conv(struct iio_dev * indio_dev)650 static void stm32h7_adc_stop_conv(struct iio_dev *indio_dev)
651 {
652 struct stm32_adc *adc = iio_priv(indio_dev);
653 int ret;
654 u32 val;
655
656 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTP);
657
658 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
659 !(val & (STM32H7_ADSTART)),
660 100, STM32_ADC_TIMEOUT_US);
661 if (ret)
662 dev_warn(&indio_dev->dev, "stop failed\n");
663
664 stm32_adc_clr_bits(adc, STM32H7_ADC_CFGR, STM32H7_DMNGT_MASK);
665 }
666
stm32h7_adc_irq_clear(struct iio_dev * indio_dev,u32 msk)667 static void stm32h7_adc_irq_clear(struct iio_dev *indio_dev, u32 msk)
668 {
669 struct stm32_adc *adc = iio_priv(indio_dev);
670 /* On STM32H7 IRQs are cleared by writing 1 into ISR register */
671 stm32_adc_set_bits(adc, adc->cfg->regs->isr_eoc.reg, msk);
672 }
673
stm32h7_adc_exit_pwr_down(struct iio_dev * indio_dev)674 static int stm32h7_adc_exit_pwr_down(struct iio_dev *indio_dev)
675 {
676 struct stm32_adc *adc = iio_priv(indio_dev);
677 int ret;
678 u32 val;
679
680 /* Exit deep power down, then enable ADC voltage regulator */
681 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
682 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADVREGEN);
683
684 if (adc->common->rate > STM32H7_BOOST_CLKRATE)
685 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST);
686
687 /* Wait for startup time */
688 if (!adc->cfg->has_vregready) {
689 usleep_range(10, 20);
690 return 0;
691 }
692
693 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val,
694 val & STM32MP1_VREGREADY, 100,
695 STM32_ADC_TIMEOUT_US);
696 if (ret) {
697 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
698 dev_err(&indio_dev->dev, "Failed to exit power down\n");
699 }
700
701 return ret;
702 }
703
stm32h7_adc_enter_pwr_down(struct stm32_adc * adc)704 static void stm32h7_adc_enter_pwr_down(struct stm32_adc *adc)
705 {
706 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST);
707
708 /* Setting DEEPPWD disables ADC vreg and clears ADVREGEN */
709 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
710 }
711
stm32h7_adc_enable(struct iio_dev * indio_dev)712 static int stm32h7_adc_enable(struct iio_dev *indio_dev)
713 {
714 struct stm32_adc *adc = iio_priv(indio_dev);
715 int ret;
716 u32 val;
717
718 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADEN);
719
720 /* Poll for ADRDY to be set (after adc startup time) */
721 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val,
722 val & STM32H7_ADRDY,
723 100, STM32_ADC_TIMEOUT_US);
724 if (ret) {
725 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS);
726 dev_err(&indio_dev->dev, "Failed to enable ADC\n");
727 } else {
728 /* Clear ADRDY by writing one */
729 stm32_adc_set_bits(adc, STM32H7_ADC_ISR, STM32H7_ADRDY);
730 }
731
732 return ret;
733 }
734
stm32h7_adc_disable(struct iio_dev * indio_dev)735 static void stm32h7_adc_disable(struct iio_dev *indio_dev)
736 {
737 struct stm32_adc *adc = iio_priv(indio_dev);
738 int ret;
739 u32 val;
740
741 /* Disable ADC and wait until it's effectively disabled */
742 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS);
743 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
744 !(val & STM32H7_ADEN), 100,
745 STM32_ADC_TIMEOUT_US);
746 if (ret)
747 dev_warn(&indio_dev->dev, "Failed to disable\n");
748 }
749
750 /**
751 * stm32h7_adc_read_selfcalib() - read calibration shadow regs, save result
752 * @indio_dev: IIO device instance
753 * Note: Must be called once ADC is enabled, so LINCALRDYW[1..6] are writable
754 */
stm32h7_adc_read_selfcalib(struct iio_dev * indio_dev)755 static int stm32h7_adc_read_selfcalib(struct iio_dev *indio_dev)
756 {
757 struct stm32_adc *adc = iio_priv(indio_dev);
758 int i, ret;
759 u32 lincalrdyw_mask, val;
760
761 /* Read linearity calibration */
762 lincalrdyw_mask = STM32H7_LINCALRDYW6;
763 for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) {
764 /* Clear STM32H7_LINCALRDYW[6..1]: transfer calib to CALFACT2 */
765 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
766
767 /* Poll: wait calib data to be ready in CALFACT2 register */
768 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
769 !(val & lincalrdyw_mask),
770 100, STM32_ADC_TIMEOUT_US);
771 if (ret) {
772 dev_err(&indio_dev->dev, "Failed to read calfact\n");
773 return ret;
774 }
775
776 val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2);
777 adc->cal.lincalfact[i] = (val & STM32H7_LINCALFACT_MASK);
778 adc->cal.lincalfact[i] >>= STM32H7_LINCALFACT_SHIFT;
779
780 lincalrdyw_mask >>= 1;
781 }
782
783 /* Read offset calibration */
784 val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT);
785 adc->cal.calfact_s = (val & STM32H7_CALFACT_S_MASK);
786 adc->cal.calfact_s >>= STM32H7_CALFACT_S_SHIFT;
787 adc->cal.calfact_d = (val & STM32H7_CALFACT_D_MASK);
788 adc->cal.calfact_d >>= STM32H7_CALFACT_D_SHIFT;
789 adc->cal.calibrated = true;
790
791 return 0;
792 }
793
794 /**
795 * stm32h7_adc_restore_selfcalib() - Restore saved self-calibration result
796 * @indio_dev: IIO device instance
797 * Note: ADC must be enabled, with no on-going conversions.
798 */
stm32h7_adc_restore_selfcalib(struct iio_dev * indio_dev)799 static int stm32h7_adc_restore_selfcalib(struct iio_dev *indio_dev)
800 {
801 struct stm32_adc *adc = iio_priv(indio_dev);
802 int i, ret;
803 u32 lincalrdyw_mask, val;
804
805 val = (adc->cal.calfact_s << STM32H7_CALFACT_S_SHIFT) |
806 (adc->cal.calfact_d << STM32H7_CALFACT_D_SHIFT);
807 stm32_adc_writel(adc, STM32H7_ADC_CALFACT, val);
808
809 lincalrdyw_mask = STM32H7_LINCALRDYW6;
810 for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) {
811 /*
812 * Write saved calibration data to shadow registers:
813 * Write CALFACT2, and set LINCALRDYW[6..1] bit to trigger
814 * data write. Then poll to wait for complete transfer.
815 */
816 val = adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT;
817 stm32_adc_writel(adc, STM32H7_ADC_CALFACT2, val);
818 stm32_adc_set_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
819 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
820 val & lincalrdyw_mask,
821 100, STM32_ADC_TIMEOUT_US);
822 if (ret) {
823 dev_err(&indio_dev->dev, "Failed to write calfact\n");
824 return ret;
825 }
826
827 /*
828 * Read back calibration data, has two effects:
829 * - It ensures bits LINCALRDYW[6..1] are kept cleared
830 * for next time calibration needs to be restored.
831 * - BTW, bit clear triggers a read, then check data has been
832 * correctly written.
833 */
834 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
835 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
836 !(val & lincalrdyw_mask),
837 100, STM32_ADC_TIMEOUT_US);
838 if (ret) {
839 dev_err(&indio_dev->dev, "Failed to read calfact\n");
840 return ret;
841 }
842 val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2);
843 if (val != adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT) {
844 dev_err(&indio_dev->dev, "calfact not consistent\n");
845 return -EIO;
846 }
847
848 lincalrdyw_mask >>= 1;
849 }
850
851 return 0;
852 }
853
854 /**
855 * Fixed timeout value for ADC calibration.
856 * worst cases:
857 * - low clock frequency
858 * - maximum prescalers
859 * Calibration requires:
860 * - 131,072 ADC clock cycle for the linear calibration
861 * - 20 ADC clock cycle for the offset calibration
862 *
863 * Set to 100ms for now
864 */
865 #define STM32H7_ADC_CALIB_TIMEOUT_US 100000
866
867 /**
868 * stm32h7_adc_selfcalib() - Procedure to calibrate ADC
869 * @indio_dev: IIO device instance
870 * Note: Must be called once ADC is out of power down.
871 */
stm32h7_adc_selfcalib(struct iio_dev * indio_dev)872 static int stm32h7_adc_selfcalib(struct iio_dev *indio_dev)
873 {
874 struct stm32_adc *adc = iio_priv(indio_dev);
875 int ret;
876 u32 val;
877
878 if (adc->cal.calibrated)
879 return true;
880
881 /*
882 * Select calibration mode:
883 * - Offset calibration for single ended inputs
884 * - No linearity calibration (do it later, before reading it)
885 */
886 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALDIF);
887 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALLIN);
888
889 /* Start calibration, then wait for completion */
890 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL);
891 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
892 !(val & STM32H7_ADCAL), 100,
893 STM32H7_ADC_CALIB_TIMEOUT_US);
894 if (ret) {
895 dev_err(&indio_dev->dev, "calibration failed\n");
896 goto out;
897 }
898
899 /*
900 * Select calibration mode, then start calibration:
901 * - Offset calibration for differential input
902 * - Linearity calibration (needs to be done only once for single/diff)
903 * will run simultaneously with offset calibration.
904 */
905 stm32_adc_set_bits(adc, STM32H7_ADC_CR,
906 STM32H7_ADCALDIF | STM32H7_ADCALLIN);
907 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL);
908 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
909 !(val & STM32H7_ADCAL), 100,
910 STM32H7_ADC_CALIB_TIMEOUT_US);
911 if (ret) {
912 dev_err(&indio_dev->dev, "calibration failed\n");
913 goto out;
914 }
915
916 out:
917 stm32_adc_clr_bits(adc, STM32H7_ADC_CR,
918 STM32H7_ADCALDIF | STM32H7_ADCALLIN);
919
920 return ret;
921 }
922
923 /**
924 * stm32h7_adc_prepare() - Leave power down mode to enable ADC.
925 * @indio_dev: IIO device instance
926 * Leave power down mode.
927 * Configure channels as single ended or differential before enabling ADC.
928 * Enable ADC.
929 * Restore calibration data.
930 * Pre-select channels that may be used in PCSEL (required by input MUX / IO):
931 * - Only one input is selected for single ended (e.g. 'vinp')
932 * - Two inputs are selected for differential channels (e.g. 'vinp' & 'vinn')
933 */
stm32h7_adc_prepare(struct iio_dev * indio_dev)934 static int stm32h7_adc_prepare(struct iio_dev *indio_dev)
935 {
936 struct stm32_adc *adc = iio_priv(indio_dev);
937 int calib, ret;
938
939 ret = stm32h7_adc_exit_pwr_down(indio_dev);
940 if (ret)
941 return ret;
942
943 ret = stm32h7_adc_selfcalib(indio_dev);
944 if (ret < 0)
945 goto pwr_dwn;
946 calib = ret;
947
948 stm32_adc_writel(adc, STM32H7_ADC_DIFSEL, adc->difsel);
949
950 ret = stm32h7_adc_enable(indio_dev);
951 if (ret)
952 goto pwr_dwn;
953
954 /* Either restore or read calibration result for future reference */
955 if (calib)
956 ret = stm32h7_adc_restore_selfcalib(indio_dev);
957 else
958 ret = stm32h7_adc_read_selfcalib(indio_dev);
959 if (ret)
960 goto disable;
961
962 stm32_adc_writel(adc, STM32H7_ADC_PCSEL, adc->pcsel);
963
964 return 0;
965
966 disable:
967 stm32h7_adc_disable(indio_dev);
968 pwr_dwn:
969 stm32h7_adc_enter_pwr_down(adc);
970
971 return ret;
972 }
973
stm32h7_adc_unprepare(struct iio_dev * indio_dev)974 static void stm32h7_adc_unprepare(struct iio_dev *indio_dev)
975 {
976 struct stm32_adc *adc = iio_priv(indio_dev);
977
978 stm32h7_adc_disable(indio_dev);
979 stm32h7_adc_enter_pwr_down(adc);
980 }
981
982 /**
983 * stm32_adc_conf_scan_seq() - Build regular channels scan sequence
984 * @indio_dev: IIO device
985 * @scan_mask: channels to be converted
986 *
987 * Conversion sequence :
988 * Apply sampling time settings for all channels.
989 * Configure ADC scan sequence based on selected channels in scan_mask.
990 * Add channels to SQR registers, from scan_mask LSB to MSB, then
991 * program sequence len.
992 */
stm32_adc_conf_scan_seq(struct iio_dev * indio_dev,const unsigned long * scan_mask)993 static int stm32_adc_conf_scan_seq(struct iio_dev *indio_dev,
994 const unsigned long *scan_mask)
995 {
996 struct stm32_adc *adc = iio_priv(indio_dev);
997 const struct stm32_adc_regs *sqr = adc->cfg->regs->sqr;
998 const struct iio_chan_spec *chan;
999 u32 val, bit;
1000 int i = 0;
1001
1002 /* Apply sampling time settings */
1003 stm32_adc_writel(adc, adc->cfg->regs->smpr[0], adc->smpr_val[0]);
1004 stm32_adc_writel(adc, adc->cfg->regs->smpr[1], adc->smpr_val[1]);
1005
1006 for_each_set_bit(bit, scan_mask, indio_dev->masklength) {
1007 chan = indio_dev->channels + bit;
1008 /*
1009 * Assign one channel per SQ entry in regular
1010 * sequence, starting with SQ1.
1011 */
1012 i++;
1013 if (i > STM32_ADC_MAX_SQ)
1014 return -EINVAL;
1015
1016 dev_dbg(&indio_dev->dev, "%s chan %d to SQ%d\n",
1017 __func__, chan->channel, i);
1018
1019 val = stm32_adc_readl(adc, sqr[i].reg);
1020 val &= ~sqr[i].mask;
1021 val |= chan->channel << sqr[i].shift;
1022 stm32_adc_writel(adc, sqr[i].reg, val);
1023 }
1024
1025 if (!i)
1026 return -EINVAL;
1027
1028 /* Sequence len */
1029 val = stm32_adc_readl(adc, sqr[0].reg);
1030 val &= ~sqr[0].mask;
1031 val |= ((i - 1) << sqr[0].shift);
1032 stm32_adc_writel(adc, sqr[0].reg, val);
1033
1034 return 0;
1035 }
1036
1037 /**
1038 * stm32_adc_get_trig_extsel() - Get external trigger selection
1039 * @indio_dev: IIO device structure
1040 * @trig: trigger
1041 *
1042 * Returns trigger extsel value, if trig matches, -EINVAL otherwise.
1043 */
stm32_adc_get_trig_extsel(struct iio_dev * indio_dev,struct iio_trigger * trig)1044 static int stm32_adc_get_trig_extsel(struct iio_dev *indio_dev,
1045 struct iio_trigger *trig)
1046 {
1047 struct stm32_adc *adc = iio_priv(indio_dev);
1048 int i;
1049
1050 /* lookup triggers registered by stm32 timer trigger driver */
1051 for (i = 0; adc->cfg->trigs[i].name; i++) {
1052 /**
1053 * Checking both stm32 timer trigger type and trig name
1054 * should be safe against arbitrary trigger names.
1055 */
1056 if ((is_stm32_timer_trigger(trig) ||
1057 is_stm32_lptim_trigger(trig)) &&
1058 !strcmp(adc->cfg->trigs[i].name, trig->name)) {
1059 return adc->cfg->trigs[i].extsel;
1060 }
1061 }
1062
1063 return -EINVAL;
1064 }
1065
1066 /**
1067 * stm32_adc_set_trig() - Set a regular trigger
1068 * @indio_dev: IIO device
1069 * @trig: IIO trigger
1070 *
1071 * Set trigger source/polarity (e.g. SW, or HW with polarity) :
1072 * - if HW trigger disabled (e.g. trig == NULL, conversion launched by sw)
1073 * - if HW trigger enabled, set source & polarity
1074 */
stm32_adc_set_trig(struct iio_dev * indio_dev,struct iio_trigger * trig)1075 static int stm32_adc_set_trig(struct iio_dev *indio_dev,
1076 struct iio_trigger *trig)
1077 {
1078 struct stm32_adc *adc = iio_priv(indio_dev);
1079 u32 val, extsel = 0, exten = STM32_EXTEN_SWTRIG;
1080 unsigned long flags;
1081 int ret;
1082
1083 if (trig) {
1084 ret = stm32_adc_get_trig_extsel(indio_dev, trig);
1085 if (ret < 0)
1086 return ret;
1087
1088 /* set trigger source and polarity (default to rising edge) */
1089 extsel = ret;
1090 exten = adc->trigger_polarity + STM32_EXTEN_HWTRIG_RISING_EDGE;
1091 }
1092
1093 spin_lock_irqsave(&adc->lock, flags);
1094 val = stm32_adc_readl(adc, adc->cfg->regs->exten.reg);
1095 val &= ~(adc->cfg->regs->exten.mask | adc->cfg->regs->extsel.mask);
1096 val |= exten << adc->cfg->regs->exten.shift;
1097 val |= extsel << adc->cfg->regs->extsel.shift;
1098 stm32_adc_writel(adc, adc->cfg->regs->exten.reg, val);
1099 spin_unlock_irqrestore(&adc->lock, flags);
1100
1101 return 0;
1102 }
1103
stm32_adc_set_trig_pol(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int type)1104 static int stm32_adc_set_trig_pol(struct iio_dev *indio_dev,
1105 const struct iio_chan_spec *chan,
1106 unsigned int type)
1107 {
1108 struct stm32_adc *adc = iio_priv(indio_dev);
1109
1110 adc->trigger_polarity = type;
1111
1112 return 0;
1113 }
1114
stm32_adc_get_trig_pol(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)1115 static int stm32_adc_get_trig_pol(struct iio_dev *indio_dev,
1116 const struct iio_chan_spec *chan)
1117 {
1118 struct stm32_adc *adc = iio_priv(indio_dev);
1119
1120 return adc->trigger_polarity;
1121 }
1122
1123 static const char * const stm32_trig_pol_items[] = {
1124 "rising-edge", "falling-edge", "both-edges",
1125 };
1126
1127 static const struct iio_enum stm32_adc_trig_pol = {
1128 .items = stm32_trig_pol_items,
1129 .num_items = ARRAY_SIZE(stm32_trig_pol_items),
1130 .get = stm32_adc_get_trig_pol,
1131 .set = stm32_adc_set_trig_pol,
1132 };
1133
1134 /**
1135 * stm32_adc_single_conv() - Performs a single conversion
1136 * @indio_dev: IIO device
1137 * @chan: IIO channel
1138 * @res: conversion result
1139 *
1140 * The function performs a single conversion on a given channel:
1141 * - Apply sampling time settings
1142 * - Program sequencer with one channel (e.g. in SQ1 with len = 1)
1143 * - Use SW trigger
1144 * - Start conversion, then wait for interrupt completion.
1145 */
stm32_adc_single_conv(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,int * res)1146 static int stm32_adc_single_conv(struct iio_dev *indio_dev,
1147 const struct iio_chan_spec *chan,
1148 int *res)
1149 {
1150 struct stm32_adc *adc = iio_priv(indio_dev);
1151 struct device *dev = indio_dev->dev.parent;
1152 const struct stm32_adc_regspec *regs = adc->cfg->regs;
1153 long timeout;
1154 u32 val;
1155 int ret;
1156
1157 reinit_completion(&adc->completion);
1158
1159 adc->bufi = 0;
1160
1161 ret = pm_runtime_get_sync(dev);
1162 if (ret < 0) {
1163 pm_runtime_put_noidle(dev);
1164 return ret;
1165 }
1166
1167 /* Apply sampling time settings */
1168 stm32_adc_writel(adc, regs->smpr[0], adc->smpr_val[0]);
1169 stm32_adc_writel(adc, regs->smpr[1], adc->smpr_val[1]);
1170
1171 /* Program chan number in regular sequence (SQ1) */
1172 val = stm32_adc_readl(adc, regs->sqr[1].reg);
1173 val &= ~regs->sqr[1].mask;
1174 val |= chan->channel << regs->sqr[1].shift;
1175 stm32_adc_writel(adc, regs->sqr[1].reg, val);
1176
1177 /* Set regular sequence len (0 for 1 conversion) */
1178 stm32_adc_clr_bits(adc, regs->sqr[0].reg, regs->sqr[0].mask);
1179
1180 /* Trigger detection disabled (conversion can be launched in SW) */
1181 stm32_adc_clr_bits(adc, regs->exten.reg, regs->exten.mask);
1182
1183 stm32_adc_conv_irq_enable(adc);
1184
1185 adc->cfg->start_conv(indio_dev, false);
1186
1187 timeout = wait_for_completion_interruptible_timeout(
1188 &adc->completion, STM32_ADC_TIMEOUT);
1189 if (timeout == 0) {
1190 ret = -ETIMEDOUT;
1191 } else if (timeout < 0) {
1192 ret = timeout;
1193 } else {
1194 *res = adc->buffer[0];
1195 ret = IIO_VAL_INT;
1196 }
1197
1198 adc->cfg->stop_conv(indio_dev);
1199
1200 stm32_adc_conv_irq_disable(adc);
1201
1202 pm_runtime_mark_last_busy(dev);
1203 pm_runtime_put_autosuspend(dev);
1204
1205 return ret;
1206 }
1207
stm32_adc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)1208 static int stm32_adc_read_raw(struct iio_dev *indio_dev,
1209 struct iio_chan_spec const *chan,
1210 int *val, int *val2, long mask)
1211 {
1212 struct stm32_adc *adc = iio_priv(indio_dev);
1213 int ret;
1214
1215 switch (mask) {
1216 case IIO_CHAN_INFO_RAW:
1217 ret = iio_device_claim_direct_mode(indio_dev);
1218 if (ret)
1219 return ret;
1220 if (chan->type == IIO_VOLTAGE)
1221 ret = stm32_adc_single_conv(indio_dev, chan, val);
1222 else
1223 ret = -EINVAL;
1224 iio_device_release_direct_mode(indio_dev);
1225 return ret;
1226
1227 case IIO_CHAN_INFO_SCALE:
1228 if (chan->differential) {
1229 *val = adc->common->vref_mv * 2;
1230 *val2 = chan->scan_type.realbits;
1231 } else {
1232 *val = adc->common->vref_mv;
1233 *val2 = chan->scan_type.realbits;
1234 }
1235 return IIO_VAL_FRACTIONAL_LOG2;
1236
1237 case IIO_CHAN_INFO_OFFSET:
1238 if (chan->differential)
1239 /* ADC_full_scale / 2 */
1240 *val = -((1 << chan->scan_type.realbits) / 2);
1241 else
1242 *val = 0;
1243 return IIO_VAL_INT;
1244
1245 default:
1246 return -EINVAL;
1247 }
1248 }
1249
stm32_adc_irq_clear(struct iio_dev * indio_dev,u32 msk)1250 static void stm32_adc_irq_clear(struct iio_dev *indio_dev, u32 msk)
1251 {
1252 struct stm32_adc *adc = iio_priv(indio_dev);
1253
1254 adc->cfg->irq_clear(indio_dev, msk);
1255 }
1256
stm32_adc_threaded_isr(int irq,void * data)1257 static irqreturn_t stm32_adc_threaded_isr(int irq, void *data)
1258 {
1259 struct iio_dev *indio_dev = data;
1260 struct stm32_adc *adc = iio_priv(indio_dev);
1261 const struct stm32_adc_regspec *regs = adc->cfg->regs;
1262 u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg);
1263 u32 mask = stm32_adc_readl(adc, regs->ier_eoc.reg);
1264
1265 /* Check ovr status right now, as ovr mask should be already disabled */
1266 if (status & regs->isr_ovr.mask) {
1267 /*
1268 * Clear ovr bit to avoid subsequent calls to IRQ handler.
1269 * This requires to stop ADC first. OVR bit state in ISR,
1270 * is propaged to CSR register by hardware.
1271 */
1272 adc->cfg->stop_conv(indio_dev);
1273 stm32_adc_irq_clear(indio_dev, regs->isr_ovr.mask);
1274 dev_err(&indio_dev->dev, "Overrun, stopping: restart needed\n");
1275 return IRQ_HANDLED;
1276 }
1277
1278 if (!(status & mask))
1279 dev_err_ratelimited(&indio_dev->dev,
1280 "Unexpected IRQ: IER=0x%08x, ISR=0x%08x\n",
1281 mask, status);
1282
1283 return IRQ_NONE;
1284 }
1285
stm32_adc_isr(int irq,void * data)1286 static irqreturn_t stm32_adc_isr(int irq, void *data)
1287 {
1288 struct iio_dev *indio_dev = data;
1289 struct stm32_adc *adc = iio_priv(indio_dev);
1290 const struct stm32_adc_regspec *regs = adc->cfg->regs;
1291 u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg);
1292 u32 mask = stm32_adc_readl(adc, regs->ier_eoc.reg);
1293
1294 if (!(status & mask))
1295 return IRQ_WAKE_THREAD;
1296
1297 if (status & regs->isr_ovr.mask) {
1298 /*
1299 * Overrun occurred on regular conversions: data for wrong
1300 * channel may be read. Unconditionally disable interrupts
1301 * to stop processing data and print error message.
1302 * Restarting the capture can be done by disabling, then
1303 * re-enabling it (e.g. write 0, then 1 to buffer/enable).
1304 */
1305 stm32_adc_ovr_irq_disable(adc);
1306 stm32_adc_conv_irq_disable(adc);
1307 return IRQ_WAKE_THREAD;
1308 }
1309
1310 if (status & regs->isr_eoc.mask) {
1311 /* Reading DR also clears EOC status flag */
1312 adc->buffer[adc->bufi] = stm32_adc_readw(adc, regs->dr);
1313 if (iio_buffer_enabled(indio_dev)) {
1314 adc->bufi++;
1315 if (adc->bufi >= adc->num_conv) {
1316 stm32_adc_conv_irq_disable(adc);
1317 iio_trigger_poll(indio_dev->trig);
1318 }
1319 } else {
1320 complete(&adc->completion);
1321 }
1322 return IRQ_HANDLED;
1323 }
1324
1325 return IRQ_NONE;
1326 }
1327
1328 /**
1329 * stm32_adc_validate_trigger() - validate trigger for stm32 adc
1330 * @indio_dev: IIO device
1331 * @trig: new trigger
1332 *
1333 * Returns: 0 if trig matches one of the triggers registered by stm32 adc
1334 * driver, -EINVAL otherwise.
1335 */
stm32_adc_validate_trigger(struct iio_dev * indio_dev,struct iio_trigger * trig)1336 static int stm32_adc_validate_trigger(struct iio_dev *indio_dev,
1337 struct iio_trigger *trig)
1338 {
1339 return stm32_adc_get_trig_extsel(indio_dev, trig) < 0 ? -EINVAL : 0;
1340 }
1341
stm32_adc_set_watermark(struct iio_dev * indio_dev,unsigned int val)1342 static int stm32_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
1343 {
1344 struct stm32_adc *adc = iio_priv(indio_dev);
1345 unsigned int watermark = STM32_DMA_BUFFER_SIZE / 2;
1346 unsigned int rx_buf_sz = STM32_DMA_BUFFER_SIZE;
1347
1348 /*
1349 * dma cyclic transfers are used, buffer is split into two periods.
1350 * There should be :
1351 * - always one buffer (period) dma is working on
1352 * - one buffer (period) driver can push data.
1353 */
1354 watermark = min(watermark, val * (unsigned)(sizeof(u16)));
1355 adc->rx_buf_sz = min(rx_buf_sz, watermark * 2 * adc->num_conv);
1356
1357 return 0;
1358 }
1359
stm32_adc_update_scan_mode(struct iio_dev * indio_dev,const unsigned long * scan_mask)1360 static int stm32_adc_update_scan_mode(struct iio_dev *indio_dev,
1361 const unsigned long *scan_mask)
1362 {
1363 struct stm32_adc *adc = iio_priv(indio_dev);
1364 struct device *dev = indio_dev->dev.parent;
1365 int ret;
1366
1367 ret = pm_runtime_get_sync(dev);
1368 if (ret < 0) {
1369 pm_runtime_put_noidle(dev);
1370 return ret;
1371 }
1372
1373 adc->num_conv = bitmap_weight(scan_mask, indio_dev->masklength);
1374
1375 ret = stm32_adc_conf_scan_seq(indio_dev, scan_mask);
1376 pm_runtime_mark_last_busy(dev);
1377 pm_runtime_put_autosuspend(dev);
1378
1379 return ret;
1380 }
1381
stm32_adc_of_xlate(struct iio_dev * indio_dev,const struct of_phandle_args * iiospec)1382 static int stm32_adc_of_xlate(struct iio_dev *indio_dev,
1383 const struct of_phandle_args *iiospec)
1384 {
1385 int i;
1386
1387 for (i = 0; i < indio_dev->num_channels; i++)
1388 if (indio_dev->channels[i].channel == iiospec->args[0])
1389 return i;
1390
1391 return -EINVAL;
1392 }
1393
1394 /**
1395 * stm32_adc_debugfs_reg_access - read or write register value
1396 * @indio_dev: IIO device structure
1397 * @reg: register offset
1398 * @writeval: value to write
1399 * @readval: value to read
1400 *
1401 * To read a value from an ADC register:
1402 * echo [ADC reg offset] > direct_reg_access
1403 * cat direct_reg_access
1404 *
1405 * To write a value in a ADC register:
1406 * echo [ADC_reg_offset] [value] > direct_reg_access
1407 */
stm32_adc_debugfs_reg_access(struct iio_dev * indio_dev,unsigned reg,unsigned writeval,unsigned * readval)1408 static int stm32_adc_debugfs_reg_access(struct iio_dev *indio_dev,
1409 unsigned reg, unsigned writeval,
1410 unsigned *readval)
1411 {
1412 struct stm32_adc *adc = iio_priv(indio_dev);
1413 struct device *dev = indio_dev->dev.parent;
1414 int ret;
1415
1416 ret = pm_runtime_get_sync(dev);
1417 if (ret < 0) {
1418 pm_runtime_put_noidle(dev);
1419 return ret;
1420 }
1421
1422 if (!readval)
1423 stm32_adc_writel(adc, reg, writeval);
1424 else
1425 *readval = stm32_adc_readl(adc, reg);
1426
1427 pm_runtime_mark_last_busy(dev);
1428 pm_runtime_put_autosuspend(dev);
1429
1430 return 0;
1431 }
1432
1433 static const struct iio_info stm32_adc_iio_info = {
1434 .read_raw = stm32_adc_read_raw,
1435 .validate_trigger = stm32_adc_validate_trigger,
1436 .hwfifo_set_watermark = stm32_adc_set_watermark,
1437 .update_scan_mode = stm32_adc_update_scan_mode,
1438 .debugfs_reg_access = stm32_adc_debugfs_reg_access,
1439 .of_xlate = stm32_adc_of_xlate,
1440 };
1441
stm32_adc_dma_residue(struct stm32_adc * adc)1442 static unsigned int stm32_adc_dma_residue(struct stm32_adc *adc)
1443 {
1444 struct dma_tx_state state;
1445 enum dma_status status;
1446
1447 status = dmaengine_tx_status(adc->dma_chan,
1448 adc->dma_chan->cookie,
1449 &state);
1450 if (status == DMA_IN_PROGRESS) {
1451 /* Residue is size in bytes from end of buffer */
1452 unsigned int i = adc->rx_buf_sz - state.residue;
1453 unsigned int size;
1454
1455 /* Return available bytes */
1456 if (i >= adc->bufi)
1457 size = i - adc->bufi;
1458 else
1459 size = adc->rx_buf_sz + i - adc->bufi;
1460
1461 return size;
1462 }
1463
1464 return 0;
1465 }
1466
stm32_adc_dma_buffer_done(void * data)1467 static void stm32_adc_dma_buffer_done(void *data)
1468 {
1469 struct iio_dev *indio_dev = data;
1470 struct stm32_adc *adc = iio_priv(indio_dev);
1471 int residue = stm32_adc_dma_residue(adc);
1472
1473 /*
1474 * In DMA mode the trigger services of IIO are not used
1475 * (e.g. no call to iio_trigger_poll).
1476 * Calling irq handler associated to the hardware trigger is not
1477 * relevant as the conversions have already been done. Data
1478 * transfers are performed directly in DMA callback instead.
1479 * This implementation avoids to call trigger irq handler that
1480 * may sleep, in an atomic context (DMA irq handler context).
1481 */
1482 dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);
1483
1484 while (residue >= indio_dev->scan_bytes) {
1485 u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi];
1486
1487 iio_push_to_buffers(indio_dev, buffer);
1488
1489 residue -= indio_dev->scan_bytes;
1490 adc->bufi += indio_dev->scan_bytes;
1491 if (adc->bufi >= adc->rx_buf_sz)
1492 adc->bufi = 0;
1493 }
1494 }
1495
stm32_adc_dma_start(struct iio_dev * indio_dev)1496 static int stm32_adc_dma_start(struct iio_dev *indio_dev)
1497 {
1498 struct stm32_adc *adc = iio_priv(indio_dev);
1499 struct dma_async_tx_descriptor *desc;
1500 dma_cookie_t cookie;
1501 int ret;
1502
1503 if (!adc->dma_chan)
1504 return 0;
1505
1506 dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
1507 adc->rx_buf_sz, adc->rx_buf_sz / 2);
1508
1509 /* Prepare a DMA cyclic transaction */
1510 desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
1511 adc->rx_dma_buf,
1512 adc->rx_buf_sz, adc->rx_buf_sz / 2,
1513 DMA_DEV_TO_MEM,
1514 DMA_PREP_INTERRUPT);
1515 if (!desc)
1516 return -EBUSY;
1517
1518 desc->callback = stm32_adc_dma_buffer_done;
1519 desc->callback_param = indio_dev;
1520
1521 cookie = dmaengine_submit(desc);
1522 ret = dma_submit_error(cookie);
1523 if (ret) {
1524 dmaengine_terminate_sync(adc->dma_chan);
1525 return ret;
1526 }
1527
1528 /* Issue pending DMA requests */
1529 dma_async_issue_pending(adc->dma_chan);
1530
1531 return 0;
1532 }
1533
stm32_adc_buffer_postenable(struct iio_dev * indio_dev)1534 static int stm32_adc_buffer_postenable(struct iio_dev *indio_dev)
1535 {
1536 struct stm32_adc *adc = iio_priv(indio_dev);
1537 struct device *dev = indio_dev->dev.parent;
1538 int ret;
1539
1540 ret = pm_runtime_get_sync(dev);
1541 if (ret < 0) {
1542 pm_runtime_put_noidle(dev);
1543 return ret;
1544 }
1545
1546 ret = stm32_adc_set_trig(indio_dev, indio_dev->trig);
1547 if (ret) {
1548 dev_err(&indio_dev->dev, "Can't set trigger\n");
1549 goto err_pm_put;
1550 }
1551
1552 ret = stm32_adc_dma_start(indio_dev);
1553 if (ret) {
1554 dev_err(&indio_dev->dev, "Can't start dma\n");
1555 goto err_clr_trig;
1556 }
1557
1558 /* Reset adc buffer index */
1559 adc->bufi = 0;
1560
1561 stm32_adc_ovr_irq_enable(adc);
1562
1563 if (!adc->dma_chan)
1564 stm32_adc_conv_irq_enable(adc);
1565
1566 adc->cfg->start_conv(indio_dev, !!adc->dma_chan);
1567
1568 return 0;
1569
1570 err_clr_trig:
1571 stm32_adc_set_trig(indio_dev, NULL);
1572 err_pm_put:
1573 pm_runtime_mark_last_busy(dev);
1574 pm_runtime_put_autosuspend(dev);
1575
1576 return ret;
1577 }
1578
stm32_adc_buffer_predisable(struct iio_dev * indio_dev)1579 static int stm32_adc_buffer_predisable(struct iio_dev *indio_dev)
1580 {
1581 struct stm32_adc *adc = iio_priv(indio_dev);
1582 struct device *dev = indio_dev->dev.parent;
1583
1584 adc->cfg->stop_conv(indio_dev);
1585 if (!adc->dma_chan)
1586 stm32_adc_conv_irq_disable(adc);
1587
1588 stm32_adc_ovr_irq_disable(adc);
1589
1590 if (adc->dma_chan)
1591 dmaengine_terminate_sync(adc->dma_chan);
1592
1593 if (stm32_adc_set_trig(indio_dev, NULL))
1594 dev_err(&indio_dev->dev, "Can't clear trigger\n");
1595
1596 pm_runtime_mark_last_busy(dev);
1597 pm_runtime_put_autosuspend(dev);
1598
1599 return 0;
1600 }
1601
1602 static const struct iio_buffer_setup_ops stm32_adc_buffer_setup_ops = {
1603 .postenable = &stm32_adc_buffer_postenable,
1604 .predisable = &stm32_adc_buffer_predisable,
1605 };
1606
stm32_adc_trigger_handler(int irq,void * p)1607 static irqreturn_t stm32_adc_trigger_handler(int irq, void *p)
1608 {
1609 struct iio_poll_func *pf = p;
1610 struct iio_dev *indio_dev = pf->indio_dev;
1611 struct stm32_adc *adc = iio_priv(indio_dev);
1612
1613 dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);
1614
1615 /* reset buffer index */
1616 adc->bufi = 0;
1617 iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,
1618 pf->timestamp);
1619 iio_trigger_notify_done(indio_dev->trig);
1620
1621 /* re-enable eoc irq */
1622 stm32_adc_conv_irq_enable(adc);
1623
1624 return IRQ_HANDLED;
1625 }
1626
1627 static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = {
1628 IIO_ENUM("trigger_polarity", IIO_SHARED_BY_ALL, &stm32_adc_trig_pol),
1629 {
1630 .name = "trigger_polarity_available",
1631 .shared = IIO_SHARED_BY_ALL,
1632 .read = iio_enum_available_read,
1633 .private = (uintptr_t)&stm32_adc_trig_pol,
1634 },
1635 {},
1636 };
1637
stm32_adc_of_get_resolution(struct iio_dev * indio_dev)1638 static int stm32_adc_of_get_resolution(struct iio_dev *indio_dev)
1639 {
1640 struct device_node *node = indio_dev->dev.of_node;
1641 struct stm32_adc *adc = iio_priv(indio_dev);
1642 unsigned int i;
1643 u32 res;
1644
1645 if (of_property_read_u32(node, "assigned-resolution-bits", &res))
1646 res = adc->cfg->adc_info->resolutions[0];
1647
1648 for (i = 0; i < adc->cfg->adc_info->num_res; i++)
1649 if (res == adc->cfg->adc_info->resolutions[i])
1650 break;
1651 if (i >= adc->cfg->adc_info->num_res) {
1652 dev_err(&indio_dev->dev, "Bad resolution: %u bits\n", res);
1653 return -EINVAL;
1654 }
1655
1656 dev_dbg(&indio_dev->dev, "Using %u bits resolution\n", res);
1657 adc->res = i;
1658
1659 return 0;
1660 }
1661
stm32_adc_smpr_init(struct stm32_adc * adc,int channel,u32 smp_ns)1662 static void stm32_adc_smpr_init(struct stm32_adc *adc, int channel, u32 smp_ns)
1663 {
1664 const struct stm32_adc_regs *smpr = &adc->cfg->regs->smp_bits[channel];
1665 u32 period_ns, shift = smpr->shift, mask = smpr->mask;
1666 unsigned int smp, r = smpr->reg;
1667
1668 /* Determine sampling time (ADC clock cycles) */
1669 period_ns = NSEC_PER_SEC / adc->common->rate;
1670 for (smp = 0; smp <= STM32_ADC_MAX_SMP; smp++)
1671 if ((period_ns * adc->cfg->smp_cycles[smp]) >= smp_ns)
1672 break;
1673 if (smp > STM32_ADC_MAX_SMP)
1674 smp = STM32_ADC_MAX_SMP;
1675
1676 /* pre-build sampling time registers (e.g. smpr1, smpr2) */
1677 adc->smpr_val[r] = (adc->smpr_val[r] & ~mask) | (smp << shift);
1678 }
1679
stm32_adc_chan_init_one(struct iio_dev * indio_dev,struct iio_chan_spec * chan,u32 vinp,u32 vinn,int scan_index,bool differential)1680 static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
1681 struct iio_chan_spec *chan, u32 vinp,
1682 u32 vinn, int scan_index, bool differential)
1683 {
1684 struct stm32_adc *adc = iio_priv(indio_dev);
1685 char *name = adc->chan_name[vinp];
1686
1687 chan->type = IIO_VOLTAGE;
1688 chan->channel = vinp;
1689 if (differential) {
1690 chan->differential = 1;
1691 chan->channel2 = vinn;
1692 snprintf(name, STM32_ADC_CH_SZ, "in%d-in%d", vinp, vinn);
1693 } else {
1694 snprintf(name, STM32_ADC_CH_SZ, "in%d", vinp);
1695 }
1696 chan->datasheet_name = name;
1697 chan->scan_index = scan_index;
1698 chan->indexed = 1;
1699 chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
1700 chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
1701 BIT(IIO_CHAN_INFO_OFFSET);
1702 chan->scan_type.sign = 'u';
1703 chan->scan_type.realbits = adc->cfg->adc_info->resolutions[adc->res];
1704 chan->scan_type.storagebits = 16;
1705 chan->ext_info = stm32_adc_ext_info;
1706
1707 /* pre-build selected channels mask */
1708 adc->pcsel |= BIT(chan->channel);
1709 if (differential) {
1710 /* pre-build diff channels mask */
1711 adc->difsel |= BIT(chan->channel);
1712 /* Also add negative input to pre-selected channels */
1713 adc->pcsel |= BIT(chan->channel2);
1714 }
1715 }
1716
stm32_adc_chan_of_init(struct iio_dev * indio_dev,bool timestamping)1717 static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping)
1718 {
1719 struct device_node *node = indio_dev->dev.of_node;
1720 struct stm32_adc *adc = iio_priv(indio_dev);
1721 const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
1722 struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
1723 struct property *prop;
1724 const __be32 *cur;
1725 struct iio_chan_spec *channels;
1726 int scan_index = 0, num_channels = 0, num_diff = 0, ret, i;
1727 u32 val, smp = 0;
1728
1729 ret = of_property_count_u32_elems(node, "st,adc-channels");
1730 if (ret > adc_info->max_channels) {
1731 dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
1732 return -EINVAL;
1733 } else if (ret > 0) {
1734 num_channels += ret;
1735 }
1736
1737 ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
1738 sizeof(*diff));
1739 if (ret > adc_info->max_channels) {
1740 dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
1741 return -EINVAL;
1742 } else if (ret > 0) {
1743 int size = ret * sizeof(*diff) / sizeof(u32);
1744
1745 num_diff = ret;
1746 num_channels += ret;
1747 ret = of_property_read_u32_array(node, "st,adc-diff-channels",
1748 (u32 *)diff, size);
1749 if (ret)
1750 return ret;
1751 }
1752
1753 if (!num_channels) {
1754 dev_err(&indio_dev->dev, "No channels configured\n");
1755 return -ENODATA;
1756 }
1757
1758 /* Optional sample time is provided either for each, or all channels */
1759 ret = of_property_count_u32_elems(node, "st,min-sample-time-nsecs");
1760 if (ret > 1 && ret != num_channels) {
1761 dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n");
1762 return -EINVAL;
1763 }
1764
1765 if (timestamping)
1766 num_channels++;
1767
1768 channels = devm_kcalloc(&indio_dev->dev, num_channels,
1769 sizeof(struct iio_chan_spec), GFP_KERNEL);
1770 if (!channels)
1771 return -ENOMEM;
1772
1773 of_property_for_each_u32(node, "st,adc-channels", prop, cur, val) {
1774 if (val >= adc_info->max_channels) {
1775 dev_err(&indio_dev->dev, "Invalid channel %d\n", val);
1776 return -EINVAL;
1777 }
1778
1779 /* Channel can't be configured both as single-ended & diff */
1780 for (i = 0; i < num_diff; i++) {
1781 if (val == diff[i].vinp) {
1782 dev_err(&indio_dev->dev,
1783 "channel %d miss-configured\n", val);
1784 return -EINVAL;
1785 }
1786 }
1787 stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
1788 0, scan_index, false);
1789 scan_index++;
1790 }
1791
1792 for (i = 0; i < num_diff; i++) {
1793 if (diff[i].vinp >= adc_info->max_channels ||
1794 diff[i].vinn >= adc_info->max_channels) {
1795 dev_err(&indio_dev->dev, "Invalid channel in%d-in%d\n",
1796 diff[i].vinp, diff[i].vinn);
1797 return -EINVAL;
1798 }
1799 stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
1800 diff[i].vinp, diff[i].vinn, scan_index,
1801 true);
1802 scan_index++;
1803 }
1804
1805 for (i = 0; i < scan_index; i++) {
1806 /*
1807 * Using of_property_read_u32_index(), smp value will only be
1808 * modified if valid u32 value can be decoded. This allows to
1809 * get either no value, 1 shared value for all indexes, or one
1810 * value per channel.
1811 */
1812 of_property_read_u32_index(node, "st,min-sample-time-nsecs",
1813 i, &smp);
1814 /* Prepare sampling time settings */
1815 stm32_adc_smpr_init(adc, channels[i].channel, smp);
1816 }
1817
1818 if (timestamping) {
1819 struct iio_chan_spec *timestamp = &channels[scan_index];
1820
1821 timestamp->type = IIO_TIMESTAMP;
1822 timestamp->channel = -1;
1823 timestamp->scan_index = scan_index;
1824 timestamp->scan_type.sign = 's';
1825 timestamp->scan_type.realbits = 64;
1826 timestamp->scan_type.storagebits = 64;
1827
1828 scan_index++;
1829 }
1830
1831 indio_dev->num_channels = scan_index;
1832 indio_dev->channels = channels;
1833
1834 return 0;
1835 }
1836
stm32_adc_dma_request(struct device * dev,struct iio_dev * indio_dev)1837 static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev)
1838 {
1839 struct stm32_adc *adc = iio_priv(indio_dev);
1840 struct dma_slave_config config;
1841 int ret;
1842
1843 adc->dma_chan = dma_request_chan(dev, "rx");
1844 if (IS_ERR(adc->dma_chan)) {
1845 ret = PTR_ERR(adc->dma_chan);
1846 if (ret != -ENODEV)
1847 return dev_err_probe(dev, ret,
1848 "DMA channel request failed with\n");
1849
1850 /* DMA is optional: fall back to IRQ mode */
1851 adc->dma_chan = NULL;
1852 return 0;
1853 }
1854
1855 adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
1856 STM32_DMA_BUFFER_SIZE,
1857 &adc->rx_dma_buf, GFP_KERNEL);
1858 if (!adc->rx_buf) {
1859 ret = -ENOMEM;
1860 goto err_release;
1861 }
1862
1863 /* Configure DMA channel to read data register */
1864 memset(&config, 0, sizeof(config));
1865 config.src_addr = (dma_addr_t)adc->common->phys_base;
1866 config.src_addr += adc->offset + adc->cfg->regs->dr;
1867 config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1868
1869 ret = dmaengine_slave_config(adc->dma_chan, &config);
1870 if (ret)
1871 goto err_free;
1872
1873 return 0;
1874
1875 err_free:
1876 dma_free_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE,
1877 adc->rx_buf, adc->rx_dma_buf);
1878 err_release:
1879 dma_release_channel(adc->dma_chan);
1880
1881 return ret;
1882 }
1883
stm32_adc_probe(struct platform_device * pdev)1884 static int stm32_adc_probe(struct platform_device *pdev)
1885 {
1886 struct iio_dev *indio_dev;
1887 struct device *dev = &pdev->dev;
1888 irqreturn_t (*handler)(int irq, void *p) = NULL;
1889 struct stm32_adc *adc;
1890 bool timestamping = false;
1891 int ret;
1892
1893 if (!pdev->dev.of_node)
1894 return -ENODEV;
1895
1896 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
1897 if (!indio_dev)
1898 return -ENOMEM;
1899
1900 adc = iio_priv(indio_dev);
1901 adc->common = dev_get_drvdata(pdev->dev.parent);
1902 spin_lock_init(&adc->lock);
1903 init_completion(&adc->completion);
1904 adc->cfg = (const struct stm32_adc_cfg *)
1905 of_match_device(dev->driver->of_match_table, dev)->data;
1906
1907 indio_dev->name = dev_name(&pdev->dev);
1908 indio_dev->dev.of_node = pdev->dev.of_node;
1909 indio_dev->info = &stm32_adc_iio_info;
1910 indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED;
1911
1912 platform_set_drvdata(pdev, indio_dev);
1913
1914 ret = of_property_read_u32(pdev->dev.of_node, "reg", &adc->offset);
1915 if (ret != 0) {
1916 dev_err(&pdev->dev, "missing reg property\n");
1917 return -EINVAL;
1918 }
1919
1920 adc->irq = platform_get_irq(pdev, 0);
1921 if (adc->irq < 0)
1922 return adc->irq;
1923
1924 ret = devm_request_threaded_irq(&pdev->dev, adc->irq, stm32_adc_isr,
1925 stm32_adc_threaded_isr,
1926 0, pdev->name, indio_dev);
1927 if (ret) {
1928 dev_err(&pdev->dev, "failed to request IRQ\n");
1929 return ret;
1930 }
1931
1932 adc->clk = devm_clk_get(&pdev->dev, NULL);
1933 if (IS_ERR(adc->clk)) {
1934 ret = PTR_ERR(adc->clk);
1935 if (ret == -ENOENT && !adc->cfg->clk_required) {
1936 adc->clk = NULL;
1937 } else {
1938 dev_err(&pdev->dev, "Can't get clock\n");
1939 return ret;
1940 }
1941 }
1942
1943 ret = stm32_adc_of_get_resolution(indio_dev);
1944 if (ret < 0)
1945 return ret;
1946
1947 ret = stm32_adc_dma_request(dev, indio_dev);
1948 if (ret < 0)
1949 return ret;
1950
1951 if (!adc->dma_chan) {
1952 /* For PIO mode only, iio_pollfunc_store_time stores a timestamp
1953 * in the primary trigger IRQ handler and stm32_adc_trigger_handler
1954 * runs in the IRQ thread to push out buffer along with timestamp.
1955 */
1956 handler = &stm32_adc_trigger_handler;
1957 timestamping = true;
1958 }
1959
1960 ret = stm32_adc_chan_of_init(indio_dev, timestamping);
1961 if (ret < 0)
1962 goto err_dma_disable;
1963
1964 ret = iio_triggered_buffer_setup(indio_dev,
1965 &iio_pollfunc_store_time, handler,
1966 &stm32_adc_buffer_setup_ops);
1967 if (ret) {
1968 dev_err(&pdev->dev, "buffer setup failed\n");
1969 goto err_dma_disable;
1970 }
1971
1972 /* Get stm32-adc-core PM online */
1973 pm_runtime_get_noresume(dev);
1974 pm_runtime_set_active(dev);
1975 pm_runtime_set_autosuspend_delay(dev, STM32_ADC_HW_STOP_DELAY_MS);
1976 pm_runtime_use_autosuspend(dev);
1977 pm_runtime_enable(dev);
1978
1979 ret = stm32_adc_hw_start(dev);
1980 if (ret)
1981 goto err_buffer_cleanup;
1982
1983 ret = iio_device_register(indio_dev);
1984 if (ret) {
1985 dev_err(&pdev->dev, "iio dev register failed\n");
1986 goto err_hw_stop;
1987 }
1988
1989 pm_runtime_mark_last_busy(dev);
1990 pm_runtime_put_autosuspend(dev);
1991
1992 return 0;
1993
1994 err_hw_stop:
1995 stm32_adc_hw_stop(dev);
1996
1997 err_buffer_cleanup:
1998 pm_runtime_disable(dev);
1999 pm_runtime_set_suspended(dev);
2000 pm_runtime_put_noidle(dev);
2001 iio_triggered_buffer_cleanup(indio_dev);
2002
2003 err_dma_disable:
2004 if (adc->dma_chan) {
2005 dma_free_coherent(adc->dma_chan->device->dev,
2006 STM32_DMA_BUFFER_SIZE,
2007 adc->rx_buf, adc->rx_dma_buf);
2008 dma_release_channel(adc->dma_chan);
2009 }
2010
2011 return ret;
2012 }
2013
stm32_adc_remove(struct platform_device * pdev)2014 static int stm32_adc_remove(struct platform_device *pdev)
2015 {
2016 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
2017 struct stm32_adc *adc = iio_priv(indio_dev);
2018
2019 pm_runtime_get_sync(&pdev->dev);
2020 iio_device_unregister(indio_dev);
2021 stm32_adc_hw_stop(&pdev->dev);
2022 pm_runtime_disable(&pdev->dev);
2023 pm_runtime_set_suspended(&pdev->dev);
2024 pm_runtime_put_noidle(&pdev->dev);
2025 iio_triggered_buffer_cleanup(indio_dev);
2026 if (adc->dma_chan) {
2027 dma_free_coherent(adc->dma_chan->device->dev,
2028 STM32_DMA_BUFFER_SIZE,
2029 adc->rx_buf, adc->rx_dma_buf);
2030 dma_release_channel(adc->dma_chan);
2031 }
2032
2033 return 0;
2034 }
2035
2036 #if defined(CONFIG_PM_SLEEP)
stm32_adc_suspend(struct device * dev)2037 static int stm32_adc_suspend(struct device *dev)
2038 {
2039 struct iio_dev *indio_dev = dev_get_drvdata(dev);
2040
2041 if (iio_buffer_enabled(indio_dev))
2042 stm32_adc_buffer_predisable(indio_dev);
2043
2044 return pm_runtime_force_suspend(dev);
2045 }
2046
stm32_adc_resume(struct device * dev)2047 static int stm32_adc_resume(struct device *dev)
2048 {
2049 struct iio_dev *indio_dev = dev_get_drvdata(dev);
2050 int ret;
2051
2052 ret = pm_runtime_force_resume(dev);
2053 if (ret < 0)
2054 return ret;
2055
2056 if (!iio_buffer_enabled(indio_dev))
2057 return 0;
2058
2059 ret = stm32_adc_update_scan_mode(indio_dev,
2060 indio_dev->active_scan_mask);
2061 if (ret < 0)
2062 return ret;
2063
2064 return stm32_adc_buffer_postenable(indio_dev);
2065 }
2066 #endif
2067
2068 #if defined(CONFIG_PM)
stm32_adc_runtime_suspend(struct device * dev)2069 static int stm32_adc_runtime_suspend(struct device *dev)
2070 {
2071 return stm32_adc_hw_stop(dev);
2072 }
2073
stm32_adc_runtime_resume(struct device * dev)2074 static int stm32_adc_runtime_resume(struct device *dev)
2075 {
2076 return stm32_adc_hw_start(dev);
2077 }
2078 #endif
2079
2080 static const struct dev_pm_ops stm32_adc_pm_ops = {
2081 SET_SYSTEM_SLEEP_PM_OPS(stm32_adc_suspend, stm32_adc_resume)
2082 SET_RUNTIME_PM_OPS(stm32_adc_runtime_suspend, stm32_adc_runtime_resume,
2083 NULL)
2084 };
2085
2086 static const struct stm32_adc_cfg stm32f4_adc_cfg = {
2087 .regs = &stm32f4_adc_regspec,
2088 .adc_info = &stm32f4_adc_info,
2089 .trigs = stm32f4_adc_trigs,
2090 .clk_required = true,
2091 .start_conv = stm32f4_adc_start_conv,
2092 .stop_conv = stm32f4_adc_stop_conv,
2093 .smp_cycles = stm32f4_adc_smp_cycles,
2094 .irq_clear = stm32f4_adc_irq_clear,
2095 };
2096
2097 static const struct stm32_adc_cfg stm32h7_adc_cfg = {
2098 .regs = &stm32h7_adc_regspec,
2099 .adc_info = &stm32h7_adc_info,
2100 .trigs = stm32h7_adc_trigs,
2101 .start_conv = stm32h7_adc_start_conv,
2102 .stop_conv = stm32h7_adc_stop_conv,
2103 .prepare = stm32h7_adc_prepare,
2104 .unprepare = stm32h7_adc_unprepare,
2105 .smp_cycles = stm32h7_adc_smp_cycles,
2106 .irq_clear = stm32h7_adc_irq_clear,
2107 };
2108
2109 static const struct stm32_adc_cfg stm32mp1_adc_cfg = {
2110 .regs = &stm32h7_adc_regspec,
2111 .adc_info = &stm32h7_adc_info,
2112 .trigs = stm32h7_adc_trigs,
2113 .has_vregready = true,
2114 .start_conv = stm32h7_adc_start_conv,
2115 .stop_conv = stm32h7_adc_stop_conv,
2116 .prepare = stm32h7_adc_prepare,
2117 .unprepare = stm32h7_adc_unprepare,
2118 .smp_cycles = stm32h7_adc_smp_cycles,
2119 .irq_clear = stm32h7_adc_irq_clear,
2120 };
2121
2122 static const struct of_device_id stm32_adc_of_match[] = {
2123 { .compatible = "st,stm32f4-adc", .data = (void *)&stm32f4_adc_cfg },
2124 { .compatible = "st,stm32h7-adc", .data = (void *)&stm32h7_adc_cfg },
2125 { .compatible = "st,stm32mp1-adc", .data = (void *)&stm32mp1_adc_cfg },
2126 {},
2127 };
2128 MODULE_DEVICE_TABLE(of, stm32_adc_of_match);
2129
2130 static struct platform_driver stm32_adc_driver = {
2131 .probe = stm32_adc_probe,
2132 .remove = stm32_adc_remove,
2133 .driver = {
2134 .name = "stm32-adc",
2135 .of_match_table = stm32_adc_of_match,
2136 .pm = &stm32_adc_pm_ops,
2137 },
2138 };
2139 module_platform_driver(stm32_adc_driver);
2140
2141 MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
2142 MODULE_DESCRIPTION("STMicroelectronics STM32 ADC IIO driver");
2143 MODULE_LICENSE("GPL v2");
2144 MODULE_ALIAS("platform:stm32-adc");
2145