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