1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * DMA support for Internal DMAC with SDHI SD/SDIO controller
4 *
5 * Copyright (C) 2016-19 Renesas Electronics Corporation
6 * Copyright (C) 2016-17 Horms Solutions, Simon Horman
7 * Copyright (C) 2018-19 Sang Engineering, Wolfram Sang
8 */
9
10 #include <linux/bitops.h>
11 #include <linux/device.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/io-64-nonatomic-hi-lo.h>
14 #include <linux/mfd/tmio.h>
15 #include <linux/mmc/host.h>
16 #include <linux/mod_devicetable.h>
17 #include <linux/module.h>
18 #include <linux/pagemap.h>
19 #include <linux/scatterlist.h>
20 #include <linux/sys_soc.h>
21
22 #include "renesas_sdhi.h"
23 #include "tmio_mmc.h"
24
25 #define DM_CM_DTRAN_MODE 0x820
26 #define DM_CM_DTRAN_CTRL 0x828
27 #define DM_CM_RST 0x830
28 #define DM_CM_INFO1 0x840
29 #define DM_CM_INFO1_MASK 0x848
30 #define DM_CM_INFO2 0x850
31 #define DM_CM_INFO2_MASK 0x858
32 #define DM_DTRAN_ADDR 0x880
33
34 /* DM_CM_DTRAN_MODE */
35 #define DTRAN_MODE_CH_NUM_CH0 0 /* "downstream" = for write commands */
36 #define DTRAN_MODE_CH_NUM_CH1 BIT(16) /* "upstream" = for read commands */
37 #define DTRAN_MODE_BUS_WIDTH (BIT(5) | BIT(4))
38 #define DTRAN_MODE_ADDR_MODE BIT(0) /* 1 = Increment address, 0 = Fixed */
39
40 /* DM_CM_DTRAN_CTRL */
41 #define DTRAN_CTRL_DM_START BIT(0)
42
43 /* DM_CM_RST */
44 #define RST_DTRANRST1 BIT(9)
45 #define RST_DTRANRST0 BIT(8)
46 #define RST_RESERVED_BITS GENMASK_ULL(31, 0)
47
48 /* DM_CM_INFO1 and DM_CM_INFO1_MASK */
49 #define INFO1_CLEAR 0
50 #define INFO1_MASK_CLEAR GENMASK_ULL(31, 0)
51 #define INFO1_DTRANEND1 BIT(17)
52 #define INFO1_DTRANEND0 BIT(16)
53
54 /* DM_CM_INFO2 and DM_CM_INFO2_MASK */
55 #define INFO2_MASK_CLEAR GENMASK_ULL(31, 0)
56 #define INFO2_DTRANERR1 BIT(17)
57 #define INFO2_DTRANERR0 BIT(16)
58
59 enum renesas_sdhi_dma_cookie {
60 COOKIE_UNMAPPED,
61 COOKIE_PRE_MAPPED,
62 COOKIE_MAPPED,
63 };
64
65 /*
66 * Specification of this driver:
67 * - host->chan_{rx,tx} will be used as a flag of enabling/disabling the dma
68 * - Since this SDHI DMAC register set has 16 but 32-bit width, we
69 * need a custom accessor.
70 */
71
72 static unsigned long global_flags;
73 /*
74 * Workaround for avoiding to use RX DMAC by multiple channels.
75 * On R-Car H3 ES1.* and M3-W ES1.0, when multiple SDHI channels use
76 * RX DMAC simultaneously, sometimes hundreds of bytes data are not
77 * stored into the system memory even if the DMAC interrupt happened.
78 * So, this driver then uses one RX DMAC channel only.
79 */
80 #define SDHI_INTERNAL_DMAC_ONE_RX_ONLY 0
81 #define SDHI_INTERNAL_DMAC_RX_IN_USE 1
82
83 /* RZ/A2 does not have the ADRR_MODE bit */
84 #define SDHI_INTERNAL_DMAC_ADDR_MODE_FIXED_ONLY 2
85
86 /* Definitions for sampling clocks */
87 static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = {
88 {
89 .clk_rate = 0,
90 .tap = 0x00000300,
91 .tap_hs400_4tap = 0x00000100,
92 },
93 };
94
95 static const struct renesas_sdhi_of_data of_rza2_compatible = {
96 .tmio_flags = TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
97 TMIO_MMC_HAVE_CBSY,
98 .tmio_ocr_mask = MMC_VDD_32_33,
99 .capabilities = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
100 MMC_CAP_CMD23 | MMC_CAP_WAIT_WHILE_BUSY,
101 .bus_shift = 2,
102 .scc_offset = 0 - 0x1000,
103 .taps = rcar_gen3_scc_taps,
104 .taps_num = ARRAY_SIZE(rcar_gen3_scc_taps),
105 /* DMAC can handle 32bit blk count but only 1 segment */
106 .max_blk_count = UINT_MAX / TMIO_MAX_BLK_SIZE,
107 .max_segs = 1,
108 };
109
110 static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = {
111 .tmio_flags = TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
112 TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
113 .capabilities = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
114 MMC_CAP_CMD23 | MMC_CAP_WAIT_WHILE_BUSY,
115 .capabilities2 = MMC_CAP2_NO_WRITE_PROTECT | MMC_CAP2_MERGE_CAPABLE,
116 .bus_shift = 2,
117 .scc_offset = 0x1000,
118 .taps = rcar_gen3_scc_taps,
119 .taps_num = ARRAY_SIZE(rcar_gen3_scc_taps),
120 /* DMAC can handle 32bit blk count but only 1 segment */
121 .max_blk_count = UINT_MAX / TMIO_MAX_BLK_SIZE,
122 .max_segs = 1,
123 };
124
125 static const struct of_device_id renesas_sdhi_internal_dmac_of_match[] = {
126 { .compatible = "renesas,sdhi-r7s9210", .data = &of_rza2_compatible, },
127 { .compatible = "renesas,sdhi-mmc-r8a77470", .data = &of_rcar_gen3_compatible, },
128 { .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_gen3_compatible, },
129 { .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_gen3_compatible, },
130 { .compatible = "renesas,rcar-gen3-sdhi", .data = &of_rcar_gen3_compatible, },
131 {},
132 };
133 MODULE_DEVICE_TABLE(of, renesas_sdhi_internal_dmac_of_match);
134
135 static void
renesas_sdhi_internal_dmac_dm_write(struct tmio_mmc_host * host,int addr,u64 val)136 renesas_sdhi_internal_dmac_dm_write(struct tmio_mmc_host *host,
137 int addr, u64 val)
138 {
139 writeq(val, host->ctl + addr);
140 }
141
142 static void
renesas_sdhi_internal_dmac_enable_dma(struct tmio_mmc_host * host,bool enable)143 renesas_sdhi_internal_dmac_enable_dma(struct tmio_mmc_host *host, bool enable)
144 {
145 struct renesas_sdhi *priv = host_to_priv(host);
146
147 if (!host->chan_tx || !host->chan_rx)
148 return;
149
150 if (!enable)
151 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1,
152 INFO1_CLEAR);
153
154 if (priv->dma_priv.enable)
155 priv->dma_priv.enable(host, enable);
156 }
157
158 static void
renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host * host)159 renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host *host) {
160 u64 val = RST_DTRANRST1 | RST_DTRANRST0;
161
162 renesas_sdhi_internal_dmac_enable_dma(host, false);
163
164 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
165 RST_RESERVED_BITS & ~val);
166 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
167 RST_RESERVED_BITS | val);
168
169 clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);
170
171 renesas_sdhi_internal_dmac_enable_dma(host, true);
172 }
173
174 static void
renesas_sdhi_internal_dmac_dataend_dma(struct tmio_mmc_host * host)175 renesas_sdhi_internal_dmac_dataend_dma(struct tmio_mmc_host *host) {
176 struct renesas_sdhi *priv = host_to_priv(host);
177
178 tasklet_schedule(&priv->dma_priv.dma_complete);
179 }
180
181 /*
182 * renesas_sdhi_internal_dmac_map() will be called with two difference
183 * sg pointers in two mmc_data by .pre_req(), but tmio host can have a single
184 * sg_ptr only. So, renesas_sdhi_internal_dmac_{un}map() should use a sg
185 * pointer in a mmc_data instead of host->sg_ptr.
186 */
187 static void
renesas_sdhi_internal_dmac_unmap(struct tmio_mmc_host * host,struct mmc_data * data,enum renesas_sdhi_dma_cookie cookie)188 renesas_sdhi_internal_dmac_unmap(struct tmio_mmc_host *host,
189 struct mmc_data *data,
190 enum renesas_sdhi_dma_cookie cookie)
191 {
192 bool unmap = cookie == COOKIE_UNMAPPED ? (data->host_cookie != cookie) :
193 (data->host_cookie == cookie);
194
195 if (unmap) {
196 dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
197 mmc_get_dma_dir(data));
198 data->host_cookie = COOKIE_UNMAPPED;
199 }
200 }
201
202 static bool
renesas_sdhi_internal_dmac_map(struct tmio_mmc_host * host,struct mmc_data * data,enum renesas_sdhi_dma_cookie cookie)203 renesas_sdhi_internal_dmac_map(struct tmio_mmc_host *host,
204 struct mmc_data *data,
205 enum renesas_sdhi_dma_cookie cookie)
206 {
207 if (data->host_cookie == COOKIE_PRE_MAPPED)
208 return true;
209
210 if (!dma_map_sg(&host->pdev->dev, data->sg, data->sg_len,
211 mmc_get_dma_dir(data)))
212 return false;
213
214 data->host_cookie = cookie;
215
216 /* This DMAC cannot handle if buffer is not 128-bytes alignment */
217 if (!IS_ALIGNED(sg_dma_address(data->sg), 128)) {
218 renesas_sdhi_internal_dmac_unmap(host, data, cookie);
219 return false;
220 }
221
222 return true;
223 }
224
225 static void
renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host * host,struct mmc_data * data)226 renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
227 struct mmc_data *data)
228 {
229 struct scatterlist *sg = host->sg_ptr;
230 u32 dtran_mode = DTRAN_MODE_BUS_WIDTH;
231
232 if (!test_bit(SDHI_INTERNAL_DMAC_ADDR_MODE_FIXED_ONLY, &global_flags))
233 dtran_mode |= DTRAN_MODE_ADDR_MODE;
234
235 if (!renesas_sdhi_internal_dmac_map(host, data, COOKIE_MAPPED))
236 goto force_pio;
237
238 if (data->flags & MMC_DATA_READ) {
239 dtran_mode |= DTRAN_MODE_CH_NUM_CH1;
240 if (test_bit(SDHI_INTERNAL_DMAC_ONE_RX_ONLY, &global_flags) &&
241 test_and_set_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags))
242 goto force_pio_with_unmap;
243 } else {
244 dtran_mode |= DTRAN_MODE_CH_NUM_CH0;
245 }
246
247 renesas_sdhi_internal_dmac_enable_dma(host, true);
248
249 /* set dma parameters */
250 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_MODE,
251 dtran_mode);
252 renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR,
253 sg_dma_address(sg));
254
255 host->dma_on = true;
256
257 return;
258
259 force_pio_with_unmap:
260 renesas_sdhi_internal_dmac_unmap(host, data, COOKIE_UNMAPPED);
261
262 force_pio:
263 renesas_sdhi_internal_dmac_enable_dma(host, false);
264 }
265
renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)266 static void renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)
267 {
268 struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
269
270 tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
271
272 /* start the DMAC */
273 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_CTRL,
274 DTRAN_CTRL_DM_START);
275 }
276
renesas_sdhi_internal_dmac_complete(struct tmio_mmc_host * host)277 static bool renesas_sdhi_internal_dmac_complete(struct tmio_mmc_host *host)
278 {
279 enum dma_data_direction dir;
280
281 if (!host->dma_on)
282 return false;
283
284 if (!host->data)
285 return false;
286
287 if (host->data->flags & MMC_DATA_READ)
288 dir = DMA_FROM_DEVICE;
289 else
290 dir = DMA_TO_DEVICE;
291
292 renesas_sdhi_internal_dmac_enable_dma(host, false);
293 renesas_sdhi_internal_dmac_unmap(host, host->data, COOKIE_MAPPED);
294
295 if (dir == DMA_FROM_DEVICE)
296 clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);
297
298 host->dma_on = false;
299
300 return true;
301 }
302
renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg)303 static void renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg)
304 {
305 struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
306
307 spin_lock_irq(&host->lock);
308 if (!renesas_sdhi_internal_dmac_complete(host))
309 goto out;
310
311 tmio_mmc_do_data_irq(host);
312 out:
313 spin_unlock_irq(&host->lock);
314 }
315
renesas_sdhi_internal_dmac_end_dma(struct tmio_mmc_host * host)316 static void renesas_sdhi_internal_dmac_end_dma(struct tmio_mmc_host *host)
317 {
318 if (host->data)
319 renesas_sdhi_internal_dmac_complete(host);
320 }
321
renesas_sdhi_internal_dmac_post_req(struct mmc_host * mmc,struct mmc_request * mrq,int err)322 static void renesas_sdhi_internal_dmac_post_req(struct mmc_host *mmc,
323 struct mmc_request *mrq,
324 int err)
325 {
326 struct tmio_mmc_host *host = mmc_priv(mmc);
327 struct mmc_data *data = mrq->data;
328
329 if (!data)
330 return;
331
332 renesas_sdhi_internal_dmac_unmap(host, data, COOKIE_UNMAPPED);
333 }
334
renesas_sdhi_internal_dmac_pre_req(struct mmc_host * mmc,struct mmc_request * mrq)335 static void renesas_sdhi_internal_dmac_pre_req(struct mmc_host *mmc,
336 struct mmc_request *mrq)
337 {
338 struct tmio_mmc_host *host = mmc_priv(mmc);
339 struct mmc_data *data = mrq->data;
340
341 if (!data)
342 return;
343
344 data->host_cookie = COOKIE_UNMAPPED;
345 renesas_sdhi_internal_dmac_map(host, data, COOKIE_PRE_MAPPED);
346 }
347
348 static void
renesas_sdhi_internal_dmac_request_dma(struct tmio_mmc_host * host,struct tmio_mmc_data * pdata)349 renesas_sdhi_internal_dmac_request_dma(struct tmio_mmc_host *host,
350 struct tmio_mmc_data *pdata)
351 {
352 struct renesas_sdhi *priv = host_to_priv(host);
353
354 /* Disable DMAC interrupts, we don't use them */
355 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1_MASK,
356 INFO1_MASK_CLEAR);
357 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO2_MASK,
358 INFO2_MASK_CLEAR);
359
360 /* Each value is set to non-zero to assume "enabling" each DMA */
361 host->chan_rx = host->chan_tx = (void *)0xdeadbeaf;
362
363 tasklet_init(&priv->dma_priv.dma_complete,
364 renesas_sdhi_internal_dmac_complete_tasklet_fn,
365 (unsigned long)host);
366 tasklet_init(&host->dma_issue,
367 renesas_sdhi_internal_dmac_issue_tasklet_fn,
368 (unsigned long)host);
369
370 /* Add pre_req and post_req */
371 host->ops.pre_req = renesas_sdhi_internal_dmac_pre_req;
372 host->ops.post_req = renesas_sdhi_internal_dmac_post_req;
373 }
374
375 static void
renesas_sdhi_internal_dmac_release_dma(struct tmio_mmc_host * host)376 renesas_sdhi_internal_dmac_release_dma(struct tmio_mmc_host *host)
377 {
378 /* Each value is set to zero to assume "disabling" each DMA */
379 host->chan_rx = host->chan_tx = NULL;
380 }
381
382 static const struct tmio_mmc_dma_ops renesas_sdhi_internal_dmac_dma_ops = {
383 .start = renesas_sdhi_internal_dmac_start_dma,
384 .enable = renesas_sdhi_internal_dmac_enable_dma,
385 .request = renesas_sdhi_internal_dmac_request_dma,
386 .release = renesas_sdhi_internal_dmac_release_dma,
387 .abort = renesas_sdhi_internal_dmac_abort_dma,
388 .dataend = renesas_sdhi_internal_dmac_dataend_dma,
389 .end = renesas_sdhi_internal_dmac_end_dma,
390 };
391
392 /*
393 * Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC
394 * implementation as others may use a different implementation.
395 */
396 static const struct soc_device_attribute soc_dma_quirks[] = {
397 { .soc_id = "r7s9210",
398 .data = (void *)BIT(SDHI_INTERNAL_DMAC_ADDR_MODE_FIXED_ONLY) },
399 { .soc_id = "r8a7795", .revision = "ES1.*",
400 .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
401 { .soc_id = "r8a7796", .revision = "ES1.0",
402 .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
403 { /* sentinel */ }
404 };
405
renesas_sdhi_internal_dmac_probe(struct platform_device * pdev)406 static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev)
407 {
408 const struct soc_device_attribute *soc = soc_device_match(soc_dma_quirks);
409 struct device *dev = &pdev->dev;
410
411 if (soc)
412 global_flags |= (unsigned long)soc->data;
413
414 /* value is max of SD_SECCNT. Confirmed by HW engineers */
415 dma_set_max_seg_size(dev, 0xffffffff);
416
417 return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops);
418 }
419
420 static const struct dev_pm_ops renesas_sdhi_internal_dmac_dev_pm_ops = {
421 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
422 pm_runtime_force_resume)
423 SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
424 tmio_mmc_host_runtime_resume,
425 NULL)
426 };
427
428 static struct platform_driver renesas_internal_dmac_sdhi_driver = {
429 .driver = {
430 .name = "renesas_sdhi_internal_dmac",
431 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
432 .pm = &renesas_sdhi_internal_dmac_dev_pm_ops,
433 .of_match_table = renesas_sdhi_internal_dmac_of_match,
434 },
435 .probe = renesas_sdhi_internal_dmac_probe,
436 .remove = renesas_sdhi_remove,
437 };
438
439 module_platform_driver(renesas_internal_dmac_sdhi_driver);
440
441 MODULE_DESCRIPTION("Renesas SDHI driver for internal DMAC");
442 MODULE_AUTHOR("Yoshihiro Shimoda");
443 MODULE_LICENSE("GPL v2");
444