1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2009
4  * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
5  */
6 
7 #include <common.h>
8 #include <clk.h>
9 #include <dm.h>
10 #include <i2c.h>
11 #include <log.h>
12 #include <malloc.h>
13 #include <pci.h>
14 #include <reset.h>
15 #include <asm/io.h>
16 #include <linux/delay.h>
17 #include "designware_i2c.h"
18 #include <dm/device_compat.h>
19 #include <linux/err.h>
20 
21 /*
22  * This assigned unique hex value is constant and is derived from the two ASCII
23  * letters 'DW' followed by a 16-bit unsigned number
24  */
25 #define DW_I2C_COMP_TYPE	0x44570140
26 
27 #ifdef CONFIG_SYS_I2C_DW_ENABLE_STATUS_UNSUPPORTED
dw_i2c_enable(struct i2c_regs * i2c_base,bool enable)28 static int  dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
29 {
30 	u32 ena = enable ? IC_ENABLE_0B : 0;
31 
32 	writel(ena, &i2c_base->ic_enable);
33 
34 	return 0;
35 }
36 #else
dw_i2c_enable(struct i2c_regs * i2c_base,bool enable)37 static int dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
38 {
39 	u32 ena = enable ? IC_ENABLE_0B : 0;
40 	int timeout = 100;
41 
42 	do {
43 		writel(ena, &i2c_base->ic_enable);
44 		if ((readl(&i2c_base->ic_enable_status) & IC_ENABLE_0B) == ena)
45 			return 0;
46 
47 		/*
48 		 * Wait 10 times the signaling period of the highest I2C
49 		 * transfer supported by the driver (for 400KHz this is
50 		 * 25us) as described in the DesignWare I2C databook.
51 		 */
52 		udelay(25);
53 	} while (timeout--);
54 	printf("timeout in %sabling I2C adapter\n", enable ? "en" : "dis");
55 
56 	return -ETIMEDOUT;
57 }
58 #endif
59 
60 /* High and low times in different speed modes (in ns) */
61 enum {
62 	/* SDA Hold Time */
63 	DEFAULT_SDA_HOLD_TIME		= 300,
64 };
65 
66 /**
67  * calc_counts() - Convert a period to a number of IC clk cycles
68  *
69  * @ic_clk: Input clock in Hz
70  * @period_ns: Period to represent, in ns
71  * @return calculated count
72  */
calc_counts(uint ic_clk,uint period_ns)73 static uint calc_counts(uint ic_clk, uint period_ns)
74 {
75 	return DIV_ROUND_UP(ic_clk / 1000 * period_ns, NANO_TO_KILO);
76 }
77 
78 /**
79  * struct i2c_mode_info - Information about an I2C speed mode
80  *
81  * Each speed mode has its own characteristics. This struct holds these to aid
82  * calculations in dw_i2c_calc_timing().
83  *
84  * @speed: Speed in Hz
85  * @min_scl_lowtime_ns: Minimum value for SCL low period in ns
86  * @min_scl_hightime_ns: Minimum value for SCL high period in ns
87  * @def_rise_time_ns: Default rise time in ns
88  * @def_fall_time_ns: Default fall time in ns
89  */
90 struct i2c_mode_info {
91 	int speed;
92 	int min_scl_hightime_ns;
93 	int min_scl_lowtime_ns;
94 	int def_rise_time_ns;
95 	int def_fall_time_ns;
96 };
97 
98 static const struct i2c_mode_info info_for_mode[] = {
99 	[IC_SPEED_MODE_STANDARD] = {
100 		I2C_SPEED_STANDARD_RATE,
101 		MIN_SS_SCL_HIGHTIME,
102 		MIN_SS_SCL_LOWTIME,
103 		1000,
104 		300,
105 	},
106 	[IC_SPEED_MODE_FAST] = {
107 		I2C_SPEED_FAST_RATE,
108 		MIN_FS_SCL_HIGHTIME,
109 		MIN_FS_SCL_LOWTIME,
110 		300,
111 		300,
112 	},
113 	[IC_SPEED_MODE_FAST_PLUS] = {
114 		I2C_SPEED_FAST_PLUS_RATE,
115 		MIN_FP_SCL_HIGHTIME,
116 		MIN_FP_SCL_LOWTIME,
117 		260,
118 		500,
119 	},
120 	[IC_SPEED_MODE_HIGH] = {
121 		I2C_SPEED_HIGH_RATE,
122 		MIN_HS_SCL_HIGHTIME,
123 		MIN_HS_SCL_LOWTIME,
124 		120,
125 		120,
126 	},
127 };
128 
129 /**
130  * dw_i2c_calc_timing() - Calculate the timings to use for a bus
131  *
132  * @priv: Bus private information (NULL if not using driver model)
133  * @mode: Speed mode to use
134  * @ic_clk: IC clock speed in Hz
135  * @spk_cnt: Spike-suppression count
136  * @config: Returns value to use
137  * @return 0 if OK, -EINVAL if the calculation failed due to invalid data
138  */
dw_i2c_calc_timing(struct dw_i2c * priv,enum i2c_speed_mode mode,int ic_clk,int spk_cnt,struct dw_i2c_speed_config * config)139 static int dw_i2c_calc_timing(struct dw_i2c *priv, enum i2c_speed_mode mode,
140 			      int ic_clk, int spk_cnt,
141 			      struct dw_i2c_speed_config *config)
142 {
143 	int fall_cnt, rise_cnt, min_tlow_cnt, min_thigh_cnt;
144 	int hcnt, lcnt, period_cnt, diff, tot;
145 	int sda_hold_time_ns, scl_rise_time_ns, scl_fall_time_ns;
146 	const struct i2c_mode_info *info;
147 
148 	/*
149 	 * Find the period, rise, fall, min tlow, and min thigh in terms of
150 	 * counts of the IC clock
151 	 */
152 	info = &info_for_mode[mode];
153 	period_cnt = ic_clk / info->speed;
154 	scl_rise_time_ns = priv && priv->scl_rise_time_ns ?
155 		 priv->scl_rise_time_ns : info->def_rise_time_ns;
156 	scl_fall_time_ns = priv && priv->scl_fall_time_ns ?
157 		 priv->scl_fall_time_ns : info->def_fall_time_ns;
158 	rise_cnt = calc_counts(ic_clk, scl_rise_time_ns);
159 	fall_cnt = calc_counts(ic_clk, scl_fall_time_ns);
160 	min_tlow_cnt = calc_counts(ic_clk, info->min_scl_lowtime_ns);
161 	min_thigh_cnt = calc_counts(ic_clk, info->min_scl_hightime_ns);
162 
163 	debug("dw_i2c: period %d rise %d fall %d tlow %d thigh %d spk %d\n",
164 	      period_cnt, rise_cnt, fall_cnt, min_tlow_cnt, min_thigh_cnt,
165 	      spk_cnt);
166 
167 	/*
168 	 * Back-solve for hcnt and lcnt according to the following equations:
169 	 * SCL_High_time = [(HCNT + IC_*_SPKLEN + 7) * ic_clk] + SCL_Fall_time
170 	 * SCL_Low_time = [(LCNT + 1) * ic_clk] - SCL_Fall_time + SCL_Rise_time
171 	 */
172 	hcnt = min_thigh_cnt - fall_cnt - 7 - spk_cnt;
173 	lcnt = min_tlow_cnt - rise_cnt + fall_cnt - 1;
174 
175 	if (hcnt < 0 || lcnt < 0) {
176 		debug("dw_i2c: bad counts. hcnt = %d lcnt = %d\n", hcnt, lcnt);
177 		return -EINVAL;
178 	}
179 
180 	/*
181 	 * Now add things back up to ensure the period is hit. If it is off,
182 	 * split the difference and bias to lcnt for remainder
183 	 */
184 	tot = hcnt + lcnt + 7 + spk_cnt + rise_cnt + 1;
185 
186 	if (tot < period_cnt) {
187 		diff = (period_cnt - tot) / 2;
188 		hcnt += diff;
189 		lcnt += diff;
190 		tot = hcnt + lcnt + 7 + spk_cnt + rise_cnt + 1;
191 		lcnt += period_cnt - tot;
192 	}
193 
194 	config->scl_lcnt = lcnt;
195 	config->scl_hcnt = hcnt;
196 
197 	/* Use internal default unless other value is specified */
198 	sda_hold_time_ns = priv && priv->sda_hold_time_ns ?
199 		 priv->sda_hold_time_ns : DEFAULT_SDA_HOLD_TIME;
200 	config->sda_hold = calc_counts(ic_clk, sda_hold_time_ns);
201 
202 	debug("dw_i2c: hcnt = %d lcnt = %d sda hold = %d\n", hcnt, lcnt,
203 	      config->sda_hold);
204 
205 	return 0;
206 }
207 
208 /**
209  * calc_bus_speed() - Calculate the config to use for a particular i2c speed
210  *
211  * @priv: Private information for the driver (NULL if not using driver model)
212  * @i2c_base: Registers for the I2C controller
213  * @speed: Required i2c speed in Hz
214  * @bus_clk: Input clock to the I2C controller in Hz (e.g. IC_CLK)
215  * @config: Returns the config to use for this speed
216  * @return 0 if OK, -ve on error
217  */
calc_bus_speed(struct dw_i2c * priv,struct i2c_regs * regs,int speed,ulong bus_clk,struct dw_i2c_speed_config * config)218 static int calc_bus_speed(struct dw_i2c *priv, struct i2c_regs *regs, int speed,
219 			  ulong bus_clk, struct dw_i2c_speed_config *config)
220 {
221 	const struct dw_scl_sda_cfg *scl_sda_cfg = NULL;
222 	enum i2c_speed_mode i2c_spd;
223 	int spk_cnt;
224 	int ret;
225 
226 	if (priv)
227 		scl_sda_cfg = priv->scl_sda_cfg;
228 	/* Allow high speed if there is no config, or the config allows it */
229 	if (speed >= I2C_SPEED_HIGH_RATE)
230 		i2c_spd = IC_SPEED_MODE_HIGH;
231 	else if (speed >= I2C_SPEED_FAST_PLUS_RATE)
232 		i2c_spd = IC_SPEED_MODE_FAST_PLUS;
233 	else if (speed >= I2C_SPEED_FAST_RATE)
234 		i2c_spd = IC_SPEED_MODE_FAST;
235 	else
236 		i2c_spd = IC_SPEED_MODE_STANDARD;
237 
238 	/* Check is high speed possible and fall back to fast mode if not */
239 	if (i2c_spd == IC_SPEED_MODE_HIGH) {
240 		u32 comp_param1;
241 
242 		comp_param1 = readl(&regs->comp_param1);
243 		if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
244 				!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH)
245 			i2c_spd = IC_SPEED_MODE_FAST;
246 	}
247 
248 	/* Get the proper spike-suppression count based on target speed */
249 	if (!priv || !priv->has_spk_cnt)
250 		spk_cnt = 0;
251 	else if (i2c_spd >= IC_SPEED_MODE_HIGH)
252 		spk_cnt = readl(&regs->hs_spklen);
253 	else
254 		spk_cnt = readl(&regs->fs_spklen);
255 	if (scl_sda_cfg) {
256 		config->sda_hold = scl_sda_cfg->sda_hold;
257 		if (i2c_spd == IC_SPEED_MODE_STANDARD) {
258 			config->scl_hcnt = scl_sda_cfg->ss_hcnt;
259 			config->scl_lcnt = scl_sda_cfg->ss_lcnt;
260 		} else if (i2c_spd == IC_SPEED_MODE_HIGH) {
261 			config->scl_hcnt = scl_sda_cfg->hs_hcnt;
262 			config->scl_lcnt = scl_sda_cfg->hs_lcnt;
263 		} else {
264 			config->scl_hcnt = scl_sda_cfg->fs_hcnt;
265 			config->scl_lcnt = scl_sda_cfg->fs_lcnt;
266 		}
267 	} else {
268 		ret = dw_i2c_calc_timing(priv, i2c_spd, bus_clk, spk_cnt,
269 					 config);
270 		if (ret)
271 			return log_msg_ret("gen_confg", ret);
272 	}
273 	config->speed_mode = i2c_spd;
274 
275 	return 0;
276 }
277 
278 /**
279  * _dw_i2c_set_bus_speed() - Set the i2c speed
280  *
281  * @priv: Private information for the driver (NULL if not using driver model)
282  * @i2c_base: Registers for the I2C controller
283  * @speed: Required i2c speed in Hz
284  * @bus_clk: Input clock to the I2C controller in Hz (e.g. IC_CLK)
285  * @return 0 if OK, -ve on error
286  */
_dw_i2c_set_bus_speed(struct dw_i2c * priv,struct i2c_regs * i2c_base,unsigned int speed,unsigned int bus_clk)287 static int _dw_i2c_set_bus_speed(struct dw_i2c *priv, struct i2c_regs *i2c_base,
288 				 unsigned int speed, unsigned int bus_clk)
289 {
290 	struct dw_i2c_speed_config config;
291 	unsigned int cntl;
292 	unsigned int ena;
293 	int ret;
294 
295 	ret = calc_bus_speed(priv, i2c_base, speed, bus_clk, &config);
296 	if (ret)
297 		return ret;
298 
299 	/* Get enable setting for restore later */
300 	ena = readl(&i2c_base->ic_enable) & IC_ENABLE_0B;
301 
302 	/* to set speed cltr must be disabled */
303 	dw_i2c_enable(i2c_base, false);
304 
305 	cntl = (readl(&i2c_base->ic_con) & (~IC_CON_SPD_MSK));
306 
307 	switch (config.speed_mode) {
308 	case IC_SPEED_MODE_HIGH:
309 		cntl |= IC_CON_SPD_HS;
310 		writel(config.scl_hcnt, &i2c_base->ic_hs_scl_hcnt);
311 		writel(config.scl_lcnt, &i2c_base->ic_hs_scl_lcnt);
312 		break;
313 	case IC_SPEED_MODE_STANDARD:
314 		cntl |= IC_CON_SPD_SS;
315 		writel(config.scl_hcnt, &i2c_base->ic_ss_scl_hcnt);
316 		writel(config.scl_lcnt, &i2c_base->ic_ss_scl_lcnt);
317 		break;
318 	case IC_SPEED_MODE_FAST_PLUS:
319 	case IC_SPEED_MODE_FAST:
320 	default:
321 		cntl |= IC_CON_SPD_FS;
322 		writel(config.scl_hcnt, &i2c_base->ic_fs_scl_hcnt);
323 		writel(config.scl_lcnt, &i2c_base->ic_fs_scl_lcnt);
324 		break;
325 	}
326 
327 	writel(cntl, &i2c_base->ic_con);
328 
329 	/* Configure SDA Hold Time if required */
330 	if (config.sda_hold)
331 		writel(config.sda_hold, &i2c_base->ic_sda_hold);
332 
333 	/* Restore back i2c now speed set */
334 	if (ena == IC_ENABLE_0B)
335 		dw_i2c_enable(i2c_base, true);
336 
337 	return 0;
338 }
339 
340 /*
341  * i2c_setaddress - Sets the target slave address
342  * @i2c_addr:	target i2c address
343  *
344  * Sets the target slave address.
345  */
i2c_setaddress(struct i2c_regs * i2c_base,unsigned int i2c_addr)346 static void i2c_setaddress(struct i2c_regs *i2c_base, unsigned int i2c_addr)
347 {
348 	/* Disable i2c */
349 	dw_i2c_enable(i2c_base, false);
350 
351 	writel(i2c_addr, &i2c_base->ic_tar);
352 
353 	/* Enable i2c */
354 	dw_i2c_enable(i2c_base, true);
355 }
356 
357 /*
358  * i2c_flush_rxfifo - Flushes the i2c RX FIFO
359  *
360  * Flushes the i2c RX FIFO
361  */
i2c_flush_rxfifo(struct i2c_regs * i2c_base)362 static void i2c_flush_rxfifo(struct i2c_regs *i2c_base)
363 {
364 	while (readl(&i2c_base->ic_status) & IC_STATUS_RFNE)
365 		readl(&i2c_base->ic_cmd_data);
366 }
367 
368 /*
369  * i2c_wait_for_bb - Waits for bus busy
370  *
371  * Waits for bus busy
372  */
i2c_wait_for_bb(struct i2c_regs * i2c_base)373 static int i2c_wait_for_bb(struct i2c_regs *i2c_base)
374 {
375 	unsigned long start_time_bb = get_timer(0);
376 
377 	while ((readl(&i2c_base->ic_status) & IC_STATUS_MA) ||
378 	       !(readl(&i2c_base->ic_status) & IC_STATUS_TFE)) {
379 
380 		/* Evaluate timeout */
381 		if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB))
382 			return 1;
383 	}
384 
385 	return 0;
386 }
387 
i2c_xfer_init(struct i2c_regs * i2c_base,uchar chip,uint addr,int alen)388 static int i2c_xfer_init(struct i2c_regs *i2c_base, uchar chip, uint addr,
389 			 int alen)
390 {
391 	if (i2c_wait_for_bb(i2c_base))
392 		return 1;
393 
394 	i2c_setaddress(i2c_base, chip);
395 	while (alen) {
396 		alen--;
397 		/* high byte address going out first */
398 		writel((addr >> (alen * 8)) & 0xff,
399 		       &i2c_base->ic_cmd_data);
400 	}
401 	return 0;
402 }
403 
i2c_xfer_finish(struct i2c_regs * i2c_base)404 static int i2c_xfer_finish(struct i2c_regs *i2c_base)
405 {
406 	ulong start_stop_det = get_timer(0);
407 
408 	while (1) {
409 		if ((readl(&i2c_base->ic_raw_intr_stat) & IC_STOP_DET)) {
410 			readl(&i2c_base->ic_clr_stop_det);
411 			break;
412 		} else if (get_timer(start_stop_det) > I2C_STOPDET_TO) {
413 			break;
414 		}
415 	}
416 
417 	if (i2c_wait_for_bb(i2c_base)) {
418 		printf("Timed out waiting for bus\n");
419 		return 1;
420 	}
421 
422 	i2c_flush_rxfifo(i2c_base);
423 
424 	return 0;
425 }
426 
427 /*
428  * i2c_read - Read from i2c memory
429  * @chip:	target i2c address
430  * @addr:	address to read from
431  * @alen:
432  * @buffer:	buffer for read data
433  * @len:	no of bytes to be read
434  *
435  * Read from i2c memory.
436  */
__dw_i2c_read(struct i2c_regs * i2c_base,u8 dev,uint addr,int alen,u8 * buffer,int len)437 static int __dw_i2c_read(struct i2c_regs *i2c_base, u8 dev, uint addr,
438 			 int alen, u8 *buffer, int len)
439 {
440 	unsigned long start_time_rx;
441 	unsigned int active = 0;
442 
443 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
444 	/*
445 	 * EEPROM chips that implement "address overflow" are ones
446 	 * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
447 	 * address and the extra bits end up in the "chip address"
448 	 * bit slots. This makes a 24WC08 (1Kbyte) chip look like
449 	 * four 256 byte chips.
450 	 *
451 	 * Note that we consider the length of the address field to
452 	 * still be one byte because the extra address bits are
453 	 * hidden in the chip address.
454 	 */
455 	dev |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
456 	addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
457 
458 	debug("%s: fix addr_overflow: dev %02x addr %02x\n", __func__, dev,
459 	      addr);
460 #endif
461 
462 	if (i2c_xfer_init(i2c_base, dev, addr, alen))
463 		return 1;
464 
465 	start_time_rx = get_timer(0);
466 	while (len) {
467 		if (!active) {
468 			/*
469 			 * Avoid writing to ic_cmd_data multiple times
470 			 * in case this loop spins too quickly and the
471 			 * ic_status RFNE bit isn't set after the first
472 			 * write. Subsequent writes to ic_cmd_data can
473 			 * trigger spurious i2c transfer.
474 			 */
475 			if (len == 1)
476 				writel(IC_CMD | IC_STOP, &i2c_base->ic_cmd_data);
477 			else
478 				writel(IC_CMD, &i2c_base->ic_cmd_data);
479 			active = 1;
480 		}
481 
482 		if (readl(&i2c_base->ic_status) & IC_STATUS_RFNE) {
483 			*buffer++ = (uchar)readl(&i2c_base->ic_cmd_data);
484 			len--;
485 			start_time_rx = get_timer(0);
486 			active = 0;
487 		} else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
488 			return 1;
489 		}
490 	}
491 
492 	return i2c_xfer_finish(i2c_base);
493 }
494 
495 /*
496  * i2c_write - Write to i2c memory
497  * @chip:	target i2c address
498  * @addr:	address to read from
499  * @alen:
500  * @buffer:	buffer for read data
501  * @len:	no of bytes to be read
502  *
503  * Write to i2c memory.
504  */
__dw_i2c_write(struct i2c_regs * i2c_base,u8 dev,uint addr,int alen,u8 * buffer,int len)505 static int __dw_i2c_write(struct i2c_regs *i2c_base, u8 dev, uint addr,
506 			  int alen, u8 *buffer, int len)
507 {
508 	int nb = len;
509 	unsigned long start_time_tx;
510 
511 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
512 	/*
513 	 * EEPROM chips that implement "address overflow" are ones
514 	 * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
515 	 * address and the extra bits end up in the "chip address"
516 	 * bit slots. This makes a 24WC08 (1Kbyte) chip look like
517 	 * four 256 byte chips.
518 	 *
519 	 * Note that we consider the length of the address field to
520 	 * still be one byte because the extra address bits are
521 	 * hidden in the chip address.
522 	 */
523 	dev |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
524 	addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
525 
526 	debug("%s: fix addr_overflow: dev %02x addr %02x\n", __func__, dev,
527 	      addr);
528 #endif
529 
530 	if (i2c_xfer_init(i2c_base, dev, addr, alen))
531 		return 1;
532 
533 	start_time_tx = get_timer(0);
534 	while (len) {
535 		if (readl(&i2c_base->ic_status) & IC_STATUS_TFNF) {
536 			if (--len == 0) {
537 				writel(*buffer | IC_STOP,
538 				       &i2c_base->ic_cmd_data);
539 			} else {
540 				writel(*buffer, &i2c_base->ic_cmd_data);
541 			}
542 			buffer++;
543 			start_time_tx = get_timer(0);
544 
545 		} else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
546 				printf("Timed out. i2c write Failed\n");
547 				return 1;
548 		}
549 	}
550 
551 	return i2c_xfer_finish(i2c_base);
552 }
553 
554 /*
555  * __dw_i2c_init - Init function
556  * @speed:	required i2c speed
557  * @slaveaddr:	slave address for the device
558  *
559  * Initialization function.
560  */
__dw_i2c_init(struct i2c_regs * i2c_base,int speed,int slaveaddr)561 static int __dw_i2c_init(struct i2c_regs *i2c_base, int speed, int slaveaddr)
562 {
563 	int ret;
564 
565 	/* Disable i2c */
566 	ret = dw_i2c_enable(i2c_base, false);
567 	if (ret)
568 		return ret;
569 
570 	writel(IC_CON_SD | IC_CON_RE | IC_CON_SPD_FS | IC_CON_MM,
571 	       &i2c_base->ic_con);
572 	writel(IC_RX_TL, &i2c_base->ic_rx_tl);
573 	writel(IC_TX_TL, &i2c_base->ic_tx_tl);
574 	writel(IC_STOP_DET, &i2c_base->ic_intr_mask);
575 #ifndef CONFIG_DM_I2C
576 	_dw_i2c_set_bus_speed(NULL, i2c_base, speed, IC_CLK);
577 	writel(slaveaddr, &i2c_base->ic_sar);
578 #endif
579 
580 	/* Enable i2c */
581 	ret = dw_i2c_enable(i2c_base, true);
582 	if (ret)
583 		return ret;
584 
585 	return 0;
586 }
587 
588 #ifndef CONFIG_DM_I2C
589 /*
590  * The legacy I2C functions. These need to get removed once
591  * all users of this driver are converted to DM.
592  */
i2c_get_base(struct i2c_adapter * adap)593 static struct i2c_regs *i2c_get_base(struct i2c_adapter *adap)
594 {
595 	switch (adap->hwadapnr) {
596 #if CONFIG_SYS_I2C_BUS_MAX >= 4
597 	case 3:
598 		return (struct i2c_regs *)CONFIG_SYS_I2C_BASE3;
599 #endif
600 #if CONFIG_SYS_I2C_BUS_MAX >= 3
601 	case 2:
602 		return (struct i2c_regs *)CONFIG_SYS_I2C_BASE2;
603 #endif
604 #if CONFIG_SYS_I2C_BUS_MAX >= 2
605 	case 1:
606 		return (struct i2c_regs *)CONFIG_SYS_I2C_BASE1;
607 #endif
608 	case 0:
609 		return (struct i2c_regs *)CONFIG_SYS_I2C_BASE;
610 	default:
611 		printf("Wrong I2C-adapter number %d\n", adap->hwadapnr);
612 	}
613 
614 	return NULL;
615 }
616 
dw_i2c_set_bus_speed(struct i2c_adapter * adap,unsigned int speed)617 static unsigned int dw_i2c_set_bus_speed(struct i2c_adapter *adap,
618 					 unsigned int speed)
619 {
620 	adap->speed = speed;
621 	return _dw_i2c_set_bus_speed(NULL, i2c_get_base(adap), speed, IC_CLK);
622 }
623 
dw_i2c_init(struct i2c_adapter * adap,int speed,int slaveaddr)624 static void dw_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
625 {
626 	__dw_i2c_init(i2c_get_base(adap), speed, slaveaddr);
627 }
628 
dw_i2c_read(struct i2c_adapter * adap,u8 dev,uint addr,int alen,u8 * buffer,int len)629 static int dw_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
630 		       int alen, u8 *buffer, int len)
631 {
632 	return __dw_i2c_read(i2c_get_base(adap), dev, addr, alen, buffer, len);
633 }
634 
dw_i2c_write(struct i2c_adapter * adap,u8 dev,uint addr,int alen,u8 * buffer,int len)635 static int dw_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
636 			int alen, u8 *buffer, int len)
637 {
638 	return __dw_i2c_write(i2c_get_base(adap), dev, addr, alen, buffer, len);
639 }
640 
641 /* dw_i2c_probe - Probe the i2c chip */
dw_i2c_probe(struct i2c_adapter * adap,u8 dev)642 static int dw_i2c_probe(struct i2c_adapter *adap, u8 dev)
643 {
644 	struct i2c_regs *i2c_base = i2c_get_base(adap);
645 	u32 tmp;
646 	int ret;
647 
648 	/*
649 	 * Try to read the first location of the chip.
650 	 */
651 	ret = __dw_i2c_read(i2c_base, dev, 0, 1, (uchar *)&tmp, 1);
652 	if (ret)
653 		dw_i2c_init(adap, adap->speed, adap->slaveaddr);
654 
655 	return ret;
656 }
657 
658 U_BOOT_I2C_ADAP_COMPLETE(dw_0, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
659 			 dw_i2c_write, dw_i2c_set_bus_speed,
660 			 CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 0)
661 
662 #if CONFIG_SYS_I2C_BUS_MAX >= 2
663 U_BOOT_I2C_ADAP_COMPLETE(dw_1, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
664 			 dw_i2c_write, dw_i2c_set_bus_speed,
665 			 CONFIG_SYS_I2C_SPEED1, CONFIG_SYS_I2C_SLAVE1, 1)
666 #endif
667 
668 #if CONFIG_SYS_I2C_BUS_MAX >= 3
669 U_BOOT_I2C_ADAP_COMPLETE(dw_2, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
670 			 dw_i2c_write, dw_i2c_set_bus_speed,
671 			 CONFIG_SYS_I2C_SPEED2, CONFIG_SYS_I2C_SLAVE2, 2)
672 #endif
673 
674 #if CONFIG_SYS_I2C_BUS_MAX >= 4
675 U_BOOT_I2C_ADAP_COMPLETE(dw_3, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
676 			 dw_i2c_write, dw_i2c_set_bus_speed,
677 			 CONFIG_SYS_I2C_SPEED3, CONFIG_SYS_I2C_SLAVE3, 3)
678 #endif
679 
680 #else /* CONFIG_DM_I2C */
681 /* The DM I2C functions */
682 
683 static int designware_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
684 			       int nmsgs)
685 {
686 	struct dw_i2c *i2c = dev_get_priv(bus);
687 	int ret;
688 
689 	debug("i2c_xfer: %d messages\n", nmsgs);
690 	for (; nmsgs > 0; nmsgs--, msg++) {
691 		debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
692 		if (msg->flags & I2C_M_RD) {
693 			ret = __dw_i2c_read(i2c->regs, msg->addr, 0, 0,
694 					    msg->buf, msg->len);
695 		} else {
696 			ret = __dw_i2c_write(i2c->regs, msg->addr, 0, 0,
697 					     msg->buf, msg->len);
698 		}
699 		if (ret) {
700 			debug("i2c_write: error sending\n");
701 			return -EREMOTEIO;
702 		}
703 	}
704 
705 	return 0;
706 }
707 
708 static int designware_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
709 {
710 	struct dw_i2c *i2c = dev_get_priv(bus);
711 	ulong rate;
712 
713 #if CONFIG_IS_ENABLED(CLK)
714 	rate = clk_get_rate(&i2c->clk);
715 	if (IS_ERR_VALUE(rate))
716 		return -EINVAL;
717 #else
718 	rate = IC_CLK;
719 #endif
720 	return _dw_i2c_set_bus_speed(i2c, i2c->regs, speed, rate);
721 }
722 
723 static int designware_i2c_probe_chip(struct udevice *bus, uint chip_addr,
724 				     uint chip_flags)
725 {
726 	struct dw_i2c *i2c = dev_get_priv(bus);
727 	struct i2c_regs *i2c_base = i2c->regs;
728 	u32 tmp;
729 	int ret;
730 
731 	/* Try to read the first location of the chip */
732 	ret = __dw_i2c_read(i2c_base, chip_addr, 0, 1, (uchar *)&tmp, 1);
733 	if (ret)
734 		__dw_i2c_init(i2c_base, 0, 0);
735 
736 	return ret;
737 }
738 
739 int designware_i2c_ofdata_to_platdata(struct udevice *bus)
740 {
741 	struct dw_i2c *priv = dev_get_priv(bus);
742 	int ret;
743 
744 	if (!priv->regs)
745 		priv->regs = (struct i2c_regs *)devfdt_get_addr_ptr(bus);
746 	dev_read_u32(bus, "i2c-scl-rising-time-ns", &priv->scl_rise_time_ns);
747 	dev_read_u32(bus, "i2c-scl-falling-time-ns", &priv->scl_fall_time_ns);
748 	dev_read_u32(bus, "i2c-sda-hold-time-ns", &priv->sda_hold_time_ns);
749 
750 	ret = reset_get_bulk(bus, &priv->resets);
751 	if (ret)
752 		dev_warn(bus, "Can't get reset: %d\n", ret);
753 	else
754 		reset_deassert_bulk(&priv->resets);
755 
756 #if CONFIG_IS_ENABLED(CLK)
757 	ret = clk_get_by_index(bus, 0, &priv->clk);
758 	if (ret)
759 		return ret;
760 
761 	ret = clk_enable(&priv->clk);
762 	if (ret && ret != -ENOSYS && ret != -ENOTSUPP) {
763 		clk_free(&priv->clk);
764 		dev_err(bus, "failed to enable clock\n");
765 		return ret;
766 	}
767 #endif
768 
769 	return 0;
770 }
771 
772 int designware_i2c_probe(struct udevice *bus)
773 {
774 	struct dw_i2c *priv = dev_get_priv(bus);
775 	uint comp_type;
776 
777 	comp_type = readl(&priv->regs->comp_type);
778 	if (comp_type != DW_I2C_COMP_TYPE) {
779 		log_err("I2C bus %s has unknown type %#x\n", bus->name,
780 			comp_type);
781 		return -ENXIO;
782 	}
783 
784 	log_info("I2C bus %s version %#x\n", bus->name,
785 		 readl(&priv->regs->comp_version));
786 
787 	return __dw_i2c_init(priv->regs, 0, 0);
788 }
789 
790 int designware_i2c_remove(struct udevice *dev)
791 {
792 	struct dw_i2c *priv = dev_get_priv(dev);
793 
794 #if CONFIG_IS_ENABLED(CLK)
795 	clk_disable(&priv->clk);
796 	clk_free(&priv->clk);
797 #endif
798 
799 	return reset_release_bulk(&priv->resets);
800 }
801 
802 const struct dm_i2c_ops designware_i2c_ops = {
803 	.xfer		= designware_i2c_xfer,
804 	.probe_chip	= designware_i2c_probe_chip,
805 	.set_bus_speed	= designware_i2c_set_bus_speed,
806 };
807 
808 static const struct udevice_id designware_i2c_ids[] = {
809 	{ .compatible = "snps,designware-i2c" },
810 	{ }
811 };
812 
813 U_BOOT_DRIVER(i2c_designware) = {
814 	.name	= "i2c_designware",
815 	.id	= UCLASS_I2C,
816 	.of_match = designware_i2c_ids,
817 	.ofdata_to_platdata = designware_i2c_ofdata_to_platdata,
818 	.probe	= designware_i2c_probe,
819 	.priv_auto_alloc_size = sizeof(struct dw_i2c),
820 	.remove = designware_i2c_remove,
821 	.flags	= DM_FLAG_OS_PREPARE,
822 	.ops	= &designware_i2c_ops,
823 };
824 
825 #endif /* CONFIG_DM_I2C */
826