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 /*
60 * Specification of this driver:
61 * - host->chan_{rx,tx} will be used as a flag of enabling/disabling the dma
62 * - Since this SDHI DMAC register set has 16 but 32-bit width, we
63 * need a custom accessor.
64 */
65
66 static unsigned long global_flags;
67 /*
68 * Workaround for avoiding to use RX DMAC by multiple channels.
69 * On R-Car H3 ES1.* and M3-W ES1.0, when multiple SDHI channels use
70 * RX DMAC simultaneously, sometimes hundreds of bytes data are not
71 * stored into the system memory even if the DMAC interrupt happened.
72 * So, this driver then uses one RX DMAC channel only.
73 */
74 #define SDHI_INTERNAL_DMAC_ONE_RX_ONLY 0
75 #define SDHI_INTERNAL_DMAC_RX_IN_USE 1
76
77 /* RZ/A2 does not have the ADRR_MODE bit */
78 #define SDHI_INTERNAL_DMAC_ADDR_MODE_FIXED_ONLY 2
79
80 /* Definitions for sampling clocks */
81 static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = {
82 {
83 .clk_rate = 0,
84 .tap = 0x00000300,
85 .tap_hs400_4tap = 0x00000100,
86 },
87 };
88
89 static const struct renesas_sdhi_of_data of_rza2_compatible = {
90 .tmio_flags = TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
91 TMIO_MMC_HAVE_CBSY,
92 .tmio_ocr_mask = MMC_VDD_32_33,
93 .capabilities = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
94 MMC_CAP_CMD23,
95 .bus_shift = 2,
96 .scc_offset = 0 - 0x1000,
97 .taps = rcar_gen3_scc_taps,
98 .taps_num = ARRAY_SIZE(rcar_gen3_scc_taps),
99 /* DMAC can handle 32bit blk count but only 1 segment */
100 .max_blk_count = UINT_MAX / TMIO_MAX_BLK_SIZE,
101 .max_segs = 1,
102 };
103
104 static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = {
105 .tmio_flags = TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
106 TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
107 .capabilities = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
108 MMC_CAP_CMD23,
109 .capabilities2 = MMC_CAP2_NO_WRITE_PROTECT | MMC_CAP2_MERGE_CAPABLE,
110 .bus_shift = 2,
111 .scc_offset = 0x1000,
112 .taps = rcar_gen3_scc_taps,
113 .taps_num = ARRAY_SIZE(rcar_gen3_scc_taps),
114 /* DMAC can handle 32bit blk count but only 1 segment */
115 .max_blk_count = UINT_MAX / TMIO_MAX_BLK_SIZE,
116 .max_segs = 1,
117 };
118
119 static const struct of_device_id renesas_sdhi_internal_dmac_of_match[] = {
120 { .compatible = "renesas,sdhi-r7s9210", .data = &of_rza2_compatible, },
121 { .compatible = "renesas,sdhi-mmc-r8a77470", .data = &of_rcar_gen3_compatible, },
122 { .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_gen3_compatible, },
123 { .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_gen3_compatible, },
124 { .compatible = "renesas,rcar-gen3-sdhi", .data = &of_rcar_gen3_compatible, },
125 {},
126 };
127 MODULE_DEVICE_TABLE(of, renesas_sdhi_internal_dmac_of_match);
128
129 static void
renesas_sdhi_internal_dmac_dm_write(struct tmio_mmc_host * host,int addr,u64 val)130 renesas_sdhi_internal_dmac_dm_write(struct tmio_mmc_host *host,
131 int addr, u64 val)
132 {
133 writeq(val, host->ctl + addr);
134 }
135
136 static void
renesas_sdhi_internal_dmac_enable_dma(struct tmio_mmc_host * host,bool enable)137 renesas_sdhi_internal_dmac_enable_dma(struct tmio_mmc_host *host, bool enable)
138 {
139 struct renesas_sdhi *priv = host_to_priv(host);
140
141 if (!host->chan_tx || !host->chan_rx)
142 return;
143
144 if (!enable)
145 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1,
146 INFO1_CLEAR);
147
148 if (priv->dma_priv.enable)
149 priv->dma_priv.enable(host, enable);
150 }
151
152 static void
renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host * host)153 renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host *host) {
154 u64 val = RST_DTRANRST1 | RST_DTRANRST0;
155
156 renesas_sdhi_internal_dmac_enable_dma(host, false);
157
158 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
159 RST_RESERVED_BITS & ~val);
160 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
161 RST_RESERVED_BITS | val);
162
163 clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);
164
165 renesas_sdhi_internal_dmac_enable_dma(host, true);
166 }
167
168 static void
renesas_sdhi_internal_dmac_dataend_dma(struct tmio_mmc_host * host)169 renesas_sdhi_internal_dmac_dataend_dma(struct tmio_mmc_host *host) {
170 struct renesas_sdhi *priv = host_to_priv(host);
171
172 tasklet_schedule(&priv->dma_priv.dma_complete);
173 }
174
175 static void
renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host * host,struct mmc_data * data)176 renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
177 struct mmc_data *data)
178 {
179 struct scatterlist *sg = host->sg_ptr;
180 u32 dtran_mode = DTRAN_MODE_BUS_WIDTH;
181
182 if (!test_bit(SDHI_INTERNAL_DMAC_ADDR_MODE_FIXED_ONLY, &global_flags))
183 dtran_mode |= DTRAN_MODE_ADDR_MODE;
184
185 if (!dma_map_sg(&host->pdev->dev, sg, host->sg_len,
186 mmc_get_dma_dir(data)))
187 goto force_pio;
188
189 /* This DMAC cannot handle if buffer is not 128-bytes alignment */
190 if (!IS_ALIGNED(sg_dma_address(sg), 128))
191 goto force_pio_with_unmap;
192
193 if (data->flags & MMC_DATA_READ) {
194 dtran_mode |= DTRAN_MODE_CH_NUM_CH1;
195 if (test_bit(SDHI_INTERNAL_DMAC_ONE_RX_ONLY, &global_flags) &&
196 test_and_set_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags))
197 goto force_pio_with_unmap;
198 } else {
199 dtran_mode |= DTRAN_MODE_CH_NUM_CH0;
200 }
201
202 renesas_sdhi_internal_dmac_enable_dma(host, true);
203
204 /* set dma parameters */
205 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_MODE,
206 dtran_mode);
207 renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR,
208 sg_dma_address(sg));
209
210 host->dma_on = true;
211
212 return;
213
214 force_pio_with_unmap:
215 dma_unmap_sg(&host->pdev->dev, sg, host->sg_len, mmc_get_dma_dir(data));
216
217 force_pio:
218 renesas_sdhi_internal_dmac_enable_dma(host, false);
219 }
220
renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)221 static void renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)
222 {
223 struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
224
225 tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
226
227 /* start the DMAC */
228 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_CTRL,
229 DTRAN_CTRL_DM_START);
230 }
231
renesas_sdhi_internal_dmac_complete(struct tmio_mmc_host * host)232 static bool renesas_sdhi_internal_dmac_complete(struct tmio_mmc_host *host)
233 {
234 enum dma_data_direction dir;
235
236 if (!host->dma_on)
237 return false;
238
239 if (!host->data)
240 return false;
241
242 if (host->data->flags & MMC_DATA_READ)
243 dir = DMA_FROM_DEVICE;
244 else
245 dir = DMA_TO_DEVICE;
246
247 renesas_sdhi_internal_dmac_enable_dma(host, false);
248 dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->sg_len, dir);
249
250 if (dir == DMA_FROM_DEVICE)
251 clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);
252
253 host->dma_on = false;
254
255 return true;
256 }
257
renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg)258 static void renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg)
259 {
260 struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
261
262 spin_lock_irq(&host->lock);
263 if (!renesas_sdhi_internal_dmac_complete(host))
264 goto out;
265
266 tmio_mmc_do_data_irq(host);
267 out:
268 spin_unlock_irq(&host->lock);
269 }
270
renesas_sdhi_internal_dmac_end_dma(struct tmio_mmc_host * host)271 static void renesas_sdhi_internal_dmac_end_dma(struct tmio_mmc_host *host)
272 {
273 if (host->data)
274 renesas_sdhi_internal_dmac_complete(host);
275 }
276
277 static void
renesas_sdhi_internal_dmac_request_dma(struct tmio_mmc_host * host,struct tmio_mmc_data * pdata)278 renesas_sdhi_internal_dmac_request_dma(struct tmio_mmc_host *host,
279 struct tmio_mmc_data *pdata)
280 {
281 struct renesas_sdhi *priv = host_to_priv(host);
282
283 /* Disable DMAC interrupts, we don't use them */
284 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1_MASK,
285 INFO1_MASK_CLEAR);
286 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO2_MASK,
287 INFO2_MASK_CLEAR);
288
289 /* Each value is set to non-zero to assume "enabling" each DMA */
290 host->chan_rx = host->chan_tx = (void *)0xdeadbeaf;
291
292 tasklet_init(&priv->dma_priv.dma_complete,
293 renesas_sdhi_internal_dmac_complete_tasklet_fn,
294 (unsigned long)host);
295 tasklet_init(&host->dma_issue,
296 renesas_sdhi_internal_dmac_issue_tasklet_fn,
297 (unsigned long)host);
298 }
299
300 static void
renesas_sdhi_internal_dmac_release_dma(struct tmio_mmc_host * host)301 renesas_sdhi_internal_dmac_release_dma(struct tmio_mmc_host *host)
302 {
303 /* Each value is set to zero to assume "disabling" each DMA */
304 host->chan_rx = host->chan_tx = NULL;
305 }
306
307 static const struct tmio_mmc_dma_ops renesas_sdhi_internal_dmac_dma_ops = {
308 .start = renesas_sdhi_internal_dmac_start_dma,
309 .enable = renesas_sdhi_internal_dmac_enable_dma,
310 .request = renesas_sdhi_internal_dmac_request_dma,
311 .release = renesas_sdhi_internal_dmac_release_dma,
312 .abort = renesas_sdhi_internal_dmac_abort_dma,
313 .dataend = renesas_sdhi_internal_dmac_dataend_dma,
314 .end = renesas_sdhi_internal_dmac_end_dma,
315 };
316
317 /*
318 * Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC
319 * implementation as others may use a different implementation.
320 */
321 static const struct soc_device_attribute soc_dma_quirks[] = {
322 { .soc_id = "r7s9210",
323 .data = (void *)BIT(SDHI_INTERNAL_DMAC_ADDR_MODE_FIXED_ONLY) },
324 { .soc_id = "r8a7795", .revision = "ES1.*",
325 .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
326 { .soc_id = "r8a7796", .revision = "ES1.0",
327 .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
328 { /* sentinel */ }
329 };
330
renesas_sdhi_internal_dmac_probe(struct platform_device * pdev)331 static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev)
332 {
333 const struct soc_device_attribute *soc = soc_device_match(soc_dma_quirks);
334 struct device *dev = &pdev->dev;
335
336 if (soc)
337 global_flags |= (unsigned long)soc->data;
338
339 /* value is max of SD_SECCNT. Confirmed by HW engineers */
340 dma_set_max_seg_size(dev, 0xffffffff);
341
342 return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops);
343 }
344
345 static const struct dev_pm_ops renesas_sdhi_internal_dmac_dev_pm_ops = {
346 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
347 pm_runtime_force_resume)
348 SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
349 tmio_mmc_host_runtime_resume,
350 NULL)
351 };
352
353 static struct platform_driver renesas_internal_dmac_sdhi_driver = {
354 .driver = {
355 .name = "renesas_sdhi_internal_dmac",
356 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
357 .pm = &renesas_sdhi_internal_dmac_dev_pm_ops,
358 .of_match_table = renesas_sdhi_internal_dmac_of_match,
359 },
360 .probe = renesas_sdhi_internal_dmac_probe,
361 .remove = renesas_sdhi_remove,
362 };
363
364 module_platform_driver(renesas_internal_dmac_sdhi_driver);
365
366 MODULE_DESCRIPTION("Renesas SDHI driver for internal DMAC");
367 MODULE_AUTHOR("Yoshihiro Shimoda");
368 MODULE_LICENSE("GPL v2");
369