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1 /*
2  * DMA support use of SYS DMAC with SDHI SD/SDIO controller
3  *
4  * Copyright (C) 2016-17 Renesas Electronics Corporation
5  * Copyright (C) 2016-17 Sang Engineering, Wolfram Sang
6  * Copyright (C) 2017 Horms Solutions, Simon Horman
7  * Copyright (C) 2010-2011 Guennadi Liakhovetski
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include <linux/device.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/dmaengine.h>
17 #include <linux/mfd/tmio.h>
18 #include <linux/mmc/host.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/module.h>
21 #include <linux/of_device.h>
22 #include <linux/pagemap.h>
23 #include <linux/scatterlist.h>
24 #include <linux/sys_soc.h>
25 
26 #include "renesas_sdhi.h"
27 #include "tmio_mmc.h"
28 
29 #define TMIO_MMC_MIN_DMA_LEN 8
30 
31 static const struct renesas_sdhi_of_data of_default_cfg = {
32 	.tmio_flags = TMIO_MMC_HAS_IDLE_WAIT,
33 };
34 
35 static const struct renesas_sdhi_of_data of_rz_compatible = {
36 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_32BIT_DATA_PORT |
37 			  TMIO_MMC_HAVE_CBSY,
38 	.tmio_ocr_mask	= MMC_VDD_32_33,
39 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
40 };
41 
42 static const struct renesas_sdhi_of_data of_rcar_gen1_compatible = {
43 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE |
44 			  TMIO_MMC_CLK_ACTUAL,
45 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
46 };
47 
48 /* Definitions for sampling clocks */
49 static struct renesas_sdhi_scc rcar_gen2_scc_taps[] = {
50 	{
51 		.clk_rate = 156000000,
52 		.tap = 0x00000703,
53 	},
54 	{
55 		.clk_rate = 0,
56 		.tap = 0x00000300,
57 	},
58 };
59 
60 static const struct renesas_sdhi_of_data of_rcar_gen2_compatible = {
61 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE |
62 			  TMIO_MMC_CLK_ACTUAL | TMIO_MMC_HAVE_CBSY |
63 			  TMIO_MMC_MIN_RCAR2,
64 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
65 			  MMC_CAP_CMD23,
66 	.dma_buswidth	= DMA_SLAVE_BUSWIDTH_4_BYTES,
67 	.dma_rx_offset	= 0x2000,
68 	.scc_offset	= 0x0300,
69 	.taps		= rcar_gen2_scc_taps,
70 	.taps_num	= ARRAY_SIZE(rcar_gen2_scc_taps),
71 	.max_blk_count  = 0xffffffff,
72 };
73 
74 /* Definitions for sampling clocks */
75 static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = {
76 	{
77 		.clk_rate = 0,
78 		.tap = 0x00000300,
79 	},
80 };
81 
82 static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = {
83 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE |
84 			  TMIO_MMC_CLK_ACTUAL | TMIO_MMC_HAVE_CBSY |
85 			  TMIO_MMC_MIN_RCAR2,
86 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
87 			  MMC_CAP_CMD23,
88 	.bus_shift	= 2,
89 	.scc_offset	= 0x1000,
90 	.taps		= rcar_gen3_scc_taps,
91 	.taps_num	= ARRAY_SIZE(rcar_gen3_scc_taps),
92 };
93 
94 static const struct of_device_id renesas_sdhi_sys_dmac_of_match[] = {
95 	{ .compatible = "renesas,sdhi-shmobile" },
96 	{ .compatible = "renesas,sdhi-sh73a0", .data = &of_default_cfg, },
97 	{ .compatible = "renesas,sdhi-r8a73a4", .data = &of_default_cfg, },
98 	{ .compatible = "renesas,sdhi-r8a7740", .data = &of_default_cfg, },
99 	{ .compatible = "renesas,sdhi-r7s72100", .data = &of_rz_compatible, },
100 	{ .compatible = "renesas,sdhi-r8a7778", .data = &of_rcar_gen1_compatible, },
101 	{ .compatible = "renesas,sdhi-r8a7779", .data = &of_rcar_gen1_compatible, },
102 	{ .compatible = "renesas,sdhi-r8a7743", .data = &of_rcar_gen2_compatible, },
103 	{ .compatible = "renesas,sdhi-r8a7745", .data = &of_rcar_gen2_compatible, },
104 	{ .compatible = "renesas,sdhi-r8a7790", .data = &of_rcar_gen2_compatible, },
105 	{ .compatible = "renesas,sdhi-r8a7791", .data = &of_rcar_gen2_compatible, },
106 	{ .compatible = "renesas,sdhi-r8a7792", .data = &of_rcar_gen2_compatible, },
107 	{ .compatible = "renesas,sdhi-r8a7793", .data = &of_rcar_gen2_compatible, },
108 	{ .compatible = "renesas,sdhi-r8a7794", .data = &of_rcar_gen2_compatible, },
109 	{ .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_gen3_compatible, },
110 	{ .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_gen3_compatible, },
111 	{},
112 };
113 MODULE_DEVICE_TABLE(of, renesas_sdhi_sys_dmac_of_match);
114 
renesas_sdhi_sys_dmac_enable_dma(struct tmio_mmc_host * host,bool enable)115 static void renesas_sdhi_sys_dmac_enable_dma(struct tmio_mmc_host *host,
116 					     bool enable)
117 {
118 	if (!host->chan_tx || !host->chan_rx)
119 		return;
120 
121 	if (host->dma->enable)
122 		host->dma->enable(host, enable);
123 }
124 
renesas_sdhi_sys_dmac_abort_dma(struct tmio_mmc_host * host)125 static void renesas_sdhi_sys_dmac_abort_dma(struct tmio_mmc_host *host)
126 {
127 	renesas_sdhi_sys_dmac_enable_dma(host, false);
128 
129 	if (host->chan_rx)
130 		dmaengine_terminate_all(host->chan_rx);
131 	if (host->chan_tx)
132 		dmaengine_terminate_all(host->chan_tx);
133 
134 	renesas_sdhi_sys_dmac_enable_dma(host, true);
135 }
136 
renesas_sdhi_sys_dmac_dataend_dma(struct tmio_mmc_host * host)137 static void renesas_sdhi_sys_dmac_dataend_dma(struct tmio_mmc_host *host)
138 {
139 	complete(&host->dma_dataend);
140 }
141 
renesas_sdhi_sys_dmac_dma_callback(void * arg)142 static void renesas_sdhi_sys_dmac_dma_callback(void *arg)
143 {
144 	struct tmio_mmc_host *host = arg;
145 
146 	spin_lock_irq(&host->lock);
147 
148 	if (!host->data)
149 		goto out;
150 
151 	if (host->data->flags & MMC_DATA_READ)
152 		dma_unmap_sg(host->chan_rx->device->dev,
153 			     host->sg_ptr, host->sg_len,
154 			     DMA_FROM_DEVICE);
155 	else
156 		dma_unmap_sg(host->chan_tx->device->dev,
157 			     host->sg_ptr, host->sg_len,
158 			     DMA_TO_DEVICE);
159 
160 	spin_unlock_irq(&host->lock);
161 
162 	wait_for_completion(&host->dma_dataend);
163 
164 	spin_lock_irq(&host->lock);
165 	tmio_mmc_do_data_irq(host);
166 out:
167 	spin_unlock_irq(&host->lock);
168 }
169 
renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host * host)170 static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
171 {
172 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
173 	struct dma_async_tx_descriptor *desc = NULL;
174 	struct dma_chan *chan = host->chan_rx;
175 	dma_cookie_t cookie;
176 	int ret, i;
177 	bool aligned = true, multiple = true;
178 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
179 
180 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
181 		if (sg_tmp->offset & align)
182 			aligned = false;
183 		if (sg_tmp->length & align) {
184 			multiple = false;
185 			break;
186 		}
187 	}
188 
189 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
190 			  (align & PAGE_MASK))) || !multiple) {
191 		ret = -EINVAL;
192 		goto pio;
193 	}
194 
195 	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
196 		host->force_pio = true;
197 		return;
198 	}
199 
200 	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);
201 
202 	/* The only sg element can be unaligned, use our bounce buffer then */
203 	if (!aligned) {
204 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
205 		host->sg_ptr = &host->bounce_sg;
206 		sg = host->sg_ptr;
207 	}
208 
209 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
210 	if (ret > 0)
211 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_DEV_TO_MEM,
212 					       DMA_CTRL_ACK);
213 
214 	if (desc) {
215 		reinit_completion(&host->dma_dataend);
216 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
217 		desc->callback_param = host;
218 
219 		cookie = dmaengine_submit(desc);
220 		if (cookie < 0) {
221 			desc = NULL;
222 			ret = cookie;
223 		}
224 	}
225 pio:
226 	if (!desc) {
227 		/* DMA failed, fall back to PIO */
228 		renesas_sdhi_sys_dmac_enable_dma(host, false);
229 		if (ret >= 0)
230 			ret = -EIO;
231 		host->chan_rx = NULL;
232 		dma_release_channel(chan);
233 		/* Free the Tx channel too */
234 		chan = host->chan_tx;
235 		if (chan) {
236 			host->chan_tx = NULL;
237 			dma_release_channel(chan);
238 		}
239 		dev_warn(&host->pdev->dev,
240 			 "DMA failed: %d, falling back to PIO\n", ret);
241 	}
242 }
243 
renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host * host)244 static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
245 {
246 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
247 	struct dma_async_tx_descriptor *desc = NULL;
248 	struct dma_chan *chan = host->chan_tx;
249 	dma_cookie_t cookie;
250 	int ret, i;
251 	bool aligned = true, multiple = true;
252 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
253 
254 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
255 		if (sg_tmp->offset & align)
256 			aligned = false;
257 		if (sg_tmp->length & align) {
258 			multiple = false;
259 			break;
260 		}
261 	}
262 
263 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
264 			  (align & PAGE_MASK))) || !multiple) {
265 		ret = -EINVAL;
266 		goto pio;
267 	}
268 
269 	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
270 		host->force_pio = true;
271 		return;
272 	}
273 
274 	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);
275 
276 	/* The only sg element can be unaligned, use our bounce buffer then */
277 	if (!aligned) {
278 		unsigned long flags;
279 		void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
280 
281 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
282 		memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
283 		tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
284 		host->sg_ptr = &host->bounce_sg;
285 		sg = host->sg_ptr;
286 	}
287 
288 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
289 	if (ret > 0)
290 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_MEM_TO_DEV,
291 					       DMA_CTRL_ACK);
292 
293 	if (desc) {
294 		reinit_completion(&host->dma_dataend);
295 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
296 		desc->callback_param = host;
297 
298 		cookie = dmaengine_submit(desc);
299 		if (cookie < 0) {
300 			desc = NULL;
301 			ret = cookie;
302 		}
303 	}
304 pio:
305 	if (!desc) {
306 		/* DMA failed, fall back to PIO */
307 		renesas_sdhi_sys_dmac_enable_dma(host, false);
308 		if (ret >= 0)
309 			ret = -EIO;
310 		host->chan_tx = NULL;
311 		dma_release_channel(chan);
312 		/* Free the Rx channel too */
313 		chan = host->chan_rx;
314 		if (chan) {
315 			host->chan_rx = NULL;
316 			dma_release_channel(chan);
317 		}
318 		dev_warn(&host->pdev->dev,
319 			 "DMA failed: %d, falling back to PIO\n", ret);
320 	}
321 }
322 
renesas_sdhi_sys_dmac_start_dma(struct tmio_mmc_host * host,struct mmc_data * data)323 static void renesas_sdhi_sys_dmac_start_dma(struct tmio_mmc_host *host,
324 					    struct mmc_data *data)
325 {
326 	if (data->flags & MMC_DATA_READ) {
327 		if (host->chan_rx)
328 			renesas_sdhi_sys_dmac_start_dma_rx(host);
329 	} else {
330 		if (host->chan_tx)
331 			renesas_sdhi_sys_dmac_start_dma_tx(host);
332 	}
333 }
334 
renesas_sdhi_sys_dmac_issue_tasklet_fn(unsigned long priv)335 static void renesas_sdhi_sys_dmac_issue_tasklet_fn(unsigned long priv)
336 {
337 	struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
338 	struct dma_chan *chan = NULL;
339 
340 	spin_lock_irq(&host->lock);
341 
342 	if (host && host->data) {
343 		if (host->data->flags & MMC_DATA_READ)
344 			chan = host->chan_rx;
345 		else
346 			chan = host->chan_tx;
347 	}
348 
349 	spin_unlock_irq(&host->lock);
350 
351 	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
352 
353 	if (chan)
354 		dma_async_issue_pending(chan);
355 }
356 
renesas_sdhi_sys_dmac_request_dma(struct tmio_mmc_host * host,struct tmio_mmc_data * pdata)357 static void renesas_sdhi_sys_dmac_request_dma(struct tmio_mmc_host *host,
358 					      struct tmio_mmc_data *pdata)
359 {
360 	/* We can only either use DMA for both Tx and Rx or not use it at all */
361 	if (!host->dma || (!host->pdev->dev.of_node &&
362 			   (!pdata->chan_priv_tx || !pdata->chan_priv_rx)))
363 		return;
364 
365 	if (!host->chan_tx && !host->chan_rx) {
366 		struct resource *res = platform_get_resource(host->pdev,
367 							     IORESOURCE_MEM, 0);
368 		struct dma_slave_config cfg = {};
369 		dma_cap_mask_t mask;
370 		int ret;
371 
372 		if (!res)
373 			return;
374 
375 		dma_cap_zero(mask);
376 		dma_cap_set(DMA_SLAVE, mask);
377 
378 		host->chan_tx = dma_request_slave_channel_compat(mask,
379 					host->dma->filter, pdata->chan_priv_tx,
380 					&host->pdev->dev, "tx");
381 		dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
382 			host->chan_tx);
383 
384 		if (!host->chan_tx)
385 			return;
386 
387 		cfg.direction = DMA_MEM_TO_DEV;
388 		cfg.dst_addr = res->start +
389 			(CTL_SD_DATA_PORT << host->bus_shift);
390 		cfg.dst_addr_width = host->dma->dma_buswidth;
391 		if (!cfg.dst_addr_width)
392 			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
393 		cfg.src_addr = 0;
394 		ret = dmaengine_slave_config(host->chan_tx, &cfg);
395 		if (ret < 0)
396 			goto ecfgtx;
397 
398 		host->chan_rx = dma_request_slave_channel_compat(mask,
399 					host->dma->filter, pdata->chan_priv_rx,
400 					&host->pdev->dev, "rx");
401 		dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
402 			host->chan_rx);
403 
404 		if (!host->chan_rx)
405 			goto ereqrx;
406 
407 		cfg.direction = DMA_DEV_TO_MEM;
408 		cfg.src_addr = cfg.dst_addr + host->pdata->dma_rx_offset;
409 		cfg.src_addr_width = host->dma->dma_buswidth;
410 		if (!cfg.src_addr_width)
411 			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
412 		cfg.dst_addr = 0;
413 		ret = dmaengine_slave_config(host->chan_rx, &cfg);
414 		if (ret < 0)
415 			goto ecfgrx;
416 
417 		host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
418 		if (!host->bounce_buf)
419 			goto ebouncebuf;
420 
421 		init_completion(&host->dma_dataend);
422 		tasklet_init(&host->dma_issue,
423 			     renesas_sdhi_sys_dmac_issue_tasklet_fn,
424 			     (unsigned long)host);
425 	}
426 
427 	renesas_sdhi_sys_dmac_enable_dma(host, true);
428 
429 	return;
430 
431 ebouncebuf:
432 ecfgrx:
433 	dma_release_channel(host->chan_rx);
434 	host->chan_rx = NULL;
435 ereqrx:
436 ecfgtx:
437 	dma_release_channel(host->chan_tx);
438 	host->chan_tx = NULL;
439 }
440 
renesas_sdhi_sys_dmac_release_dma(struct tmio_mmc_host * host)441 static void renesas_sdhi_sys_dmac_release_dma(struct tmio_mmc_host *host)
442 {
443 	if (host->chan_tx) {
444 		struct dma_chan *chan = host->chan_tx;
445 
446 		host->chan_tx = NULL;
447 		dma_release_channel(chan);
448 	}
449 	if (host->chan_rx) {
450 		struct dma_chan *chan = host->chan_rx;
451 
452 		host->chan_rx = NULL;
453 		dma_release_channel(chan);
454 	}
455 	if (host->bounce_buf) {
456 		free_pages((unsigned long)host->bounce_buf, 0);
457 		host->bounce_buf = NULL;
458 	}
459 }
460 
461 static const struct tmio_mmc_dma_ops renesas_sdhi_sys_dmac_dma_ops = {
462 	.start = renesas_sdhi_sys_dmac_start_dma,
463 	.enable = renesas_sdhi_sys_dmac_enable_dma,
464 	.request = renesas_sdhi_sys_dmac_request_dma,
465 	.release = renesas_sdhi_sys_dmac_release_dma,
466 	.abort = renesas_sdhi_sys_dmac_abort_dma,
467 	.dataend = renesas_sdhi_sys_dmac_dataend_dma,
468 };
469 
470 /*
471  * Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC
472  * implementation. Currently empty as all supported ES versions use
473  * the internal DMAC.
474  */
475 static const struct soc_device_attribute gen3_soc_whitelist[] = {
476         { /* sentinel */ }
477 };
478 
renesas_sdhi_sys_dmac_probe(struct platform_device * pdev)479 static int renesas_sdhi_sys_dmac_probe(struct platform_device *pdev)
480 {
481 	if (of_device_get_match_data(&pdev->dev) == &of_rcar_gen3_compatible &&
482 	    !soc_device_match(gen3_soc_whitelist))
483 		return -ENODEV;
484 
485 	return renesas_sdhi_probe(pdev, &renesas_sdhi_sys_dmac_dma_ops);
486 }
487 
488 static const struct dev_pm_ops renesas_sdhi_sys_dmac_dev_pm_ops = {
489 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
490 				pm_runtime_force_resume)
491 	SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
492 			   tmio_mmc_host_runtime_resume,
493 			   NULL)
494 };
495 
496 static struct platform_driver renesas_sys_dmac_sdhi_driver = {
497 	.driver		= {
498 		.name	= "sh_mobile_sdhi",
499 		.pm	= &renesas_sdhi_sys_dmac_dev_pm_ops,
500 		.of_match_table = renesas_sdhi_sys_dmac_of_match,
501 	},
502 	.probe		= renesas_sdhi_sys_dmac_probe,
503 	.remove		= renesas_sdhi_remove,
504 };
505 
506 module_platform_driver(renesas_sys_dmac_sdhi_driver);
507 
508 MODULE_DESCRIPTION("Renesas SDHI driver");
509 MODULE_AUTHOR("Magnus Damm");
510 MODULE_LICENSE("GPL v2");
511 MODULE_ALIAS("platform:sh_mobile_sdhi");
512