1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * DMA support use of SYS DMAC with SDHI SD/SDIO controller
4  *
5  * Copyright (C) 2016-19 Renesas Electronics Corporation
6  * Copyright (C) 2016-19 Sang Engineering, Wolfram Sang
7  * Copyright (C) 2017 Horms Solutions, Simon Horman
8  * Copyright (C) 2010-2011 Guennadi Liakhovetski
9  */
10 
11 #include <linux/device.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/dmaengine.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/of_device.h>
19 #include <linux/pagemap.h>
20 #include <linux/scatterlist.h>
21 #include <linux/sys_soc.h>
22 
23 #include "renesas_sdhi.h"
24 #include "tmio_mmc.h"
25 
26 #define TMIO_MMC_MIN_DMA_LEN 8
27 
28 static const struct renesas_sdhi_of_data of_default_cfg = {
29 	.tmio_flags = TMIO_MMC_HAS_IDLE_WAIT,
30 };
31 
32 static const struct renesas_sdhi_of_data of_rz_compatible = {
33 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_32BIT_DATA_PORT |
34 			  TMIO_MMC_HAVE_CBSY,
35 	.tmio_ocr_mask	= MMC_VDD_32_33,
36 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
37 };
38 
39 static const struct renesas_sdhi_of_data of_rcar_gen1_compatible = {
40 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL,
41 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
42 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
43 };
44 
45 /* Definitions for sampling clocks */
46 static struct renesas_sdhi_scc rcar_gen2_scc_taps[] = {
47 	{
48 		.clk_rate = 156000000,
49 		.tap = 0x00000703,
50 	},
51 	{
52 		.clk_rate = 0,
53 		.tap = 0x00000300,
54 	},
55 };
56 
57 static const struct renesas_sdhi_of_data of_rcar_gen2_compatible = {
58 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
59 			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
60 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
61 			  MMC_CAP_CMD23,
62 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
63 	.dma_buswidth	= DMA_SLAVE_BUSWIDTH_4_BYTES,
64 	.dma_rx_offset	= 0x2000,
65 	.scc_offset	= 0x0300,
66 	.taps		= rcar_gen2_scc_taps,
67 	.taps_num	= ARRAY_SIZE(rcar_gen2_scc_taps),
68 	.max_blk_count	= UINT_MAX / TMIO_MAX_BLK_SIZE,
69 };
70 
71 static const struct of_device_id renesas_sdhi_sys_dmac_of_match[] = {
72 	{ .compatible = "renesas,sdhi-sh73a0", .data = &of_default_cfg, },
73 	{ .compatible = "renesas,sdhi-r8a73a4", .data = &of_default_cfg, },
74 	{ .compatible = "renesas,sdhi-r8a7740", .data = &of_default_cfg, },
75 	{ .compatible = "renesas,sdhi-r7s72100", .data = &of_rz_compatible, },
76 	{ .compatible = "renesas,sdhi-r8a7778", .data = &of_rcar_gen1_compatible, },
77 	{ .compatible = "renesas,sdhi-r8a7779", .data = &of_rcar_gen1_compatible, },
78 	{ .compatible = "renesas,sdhi-r8a7743", .data = &of_rcar_gen2_compatible, },
79 	{ .compatible = "renesas,sdhi-r8a7745", .data = &of_rcar_gen2_compatible, },
80 	{ .compatible = "renesas,sdhi-r8a7790", .data = &of_rcar_gen2_compatible, },
81 	{ .compatible = "renesas,sdhi-r8a7791", .data = &of_rcar_gen2_compatible, },
82 	{ .compatible = "renesas,sdhi-r8a7792", .data = &of_rcar_gen2_compatible, },
83 	{ .compatible = "renesas,sdhi-r8a7793", .data = &of_rcar_gen2_compatible, },
84 	{ .compatible = "renesas,sdhi-r8a7794", .data = &of_rcar_gen2_compatible, },
85 	{ .compatible = "renesas,rcar-gen1-sdhi", .data = &of_rcar_gen1_compatible, },
86 	{ .compatible = "renesas,rcar-gen2-sdhi", .data = &of_rcar_gen2_compatible, },
87 	{ .compatible = "renesas,sdhi-shmobile" },
88 	{},
89 };
90 MODULE_DEVICE_TABLE(of, renesas_sdhi_sys_dmac_of_match);
91 
92 static void renesas_sdhi_sys_dmac_enable_dma(struct tmio_mmc_host *host,
93 					     bool enable)
94 {
95 	struct renesas_sdhi *priv = host_to_priv(host);
96 
97 	if (!host->chan_tx || !host->chan_rx)
98 		return;
99 
100 	if (priv->dma_priv.enable)
101 		priv->dma_priv.enable(host, enable);
102 }
103 
104 static void renesas_sdhi_sys_dmac_abort_dma(struct tmio_mmc_host *host)
105 {
106 	renesas_sdhi_sys_dmac_enable_dma(host, false);
107 
108 	if (host->chan_rx)
109 		dmaengine_terminate_all(host->chan_rx);
110 	if (host->chan_tx)
111 		dmaengine_terminate_all(host->chan_tx);
112 
113 	renesas_sdhi_sys_dmac_enable_dma(host, true);
114 }
115 
116 static void renesas_sdhi_sys_dmac_dataend_dma(struct tmio_mmc_host *host)
117 {
118 	struct renesas_sdhi *priv = host_to_priv(host);
119 
120 	complete(&priv->dma_priv.dma_dataend);
121 }
122 
123 static void renesas_sdhi_sys_dmac_dma_callback(void *arg)
124 {
125 	struct tmio_mmc_host *host = arg;
126 	struct renesas_sdhi *priv = host_to_priv(host);
127 
128 	spin_lock_irq(&host->lock);
129 
130 	if (!host->data)
131 		goto out;
132 
133 	if (host->data->flags & MMC_DATA_READ)
134 		dma_unmap_sg(host->chan_rx->device->dev,
135 			     host->sg_ptr, host->sg_len,
136 			     DMA_FROM_DEVICE);
137 	else
138 		dma_unmap_sg(host->chan_tx->device->dev,
139 			     host->sg_ptr, host->sg_len,
140 			     DMA_TO_DEVICE);
141 
142 	spin_unlock_irq(&host->lock);
143 
144 	wait_for_completion(&priv->dma_priv.dma_dataend);
145 
146 	spin_lock_irq(&host->lock);
147 	tmio_mmc_do_data_irq(host);
148 out:
149 	spin_unlock_irq(&host->lock);
150 }
151 
152 static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
153 {
154 	struct renesas_sdhi *priv = host_to_priv(host);
155 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
156 	struct dma_async_tx_descriptor *desc = NULL;
157 	struct dma_chan *chan = host->chan_rx;
158 	dma_cookie_t cookie;
159 	int ret, i;
160 	bool aligned = true, multiple = true;
161 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
162 
163 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
164 		if (sg_tmp->offset & align)
165 			aligned = false;
166 		if (sg_tmp->length & align) {
167 			multiple = false;
168 			break;
169 		}
170 	}
171 
172 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
173 			  (align & PAGE_MASK))) || !multiple) {
174 		ret = -EINVAL;
175 		goto pio;
176 	}
177 
178 	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
179 		return;
180 
181 	/* The only sg element can be unaligned, use our bounce buffer then */
182 	if (!aligned) {
183 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
184 		host->sg_ptr = &host->bounce_sg;
185 		sg = host->sg_ptr;
186 	}
187 
188 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
189 	if (ret > 0)
190 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_DEV_TO_MEM,
191 					       DMA_CTRL_ACK);
192 
193 	if (desc) {
194 		reinit_completion(&priv->dma_priv.dma_dataend);
195 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
196 		desc->callback_param = host;
197 
198 		cookie = dmaengine_submit(desc);
199 		if (cookie < 0) {
200 			desc = NULL;
201 			ret = cookie;
202 		}
203 		host->dma_on = true;
204 	}
205 pio:
206 	if (!desc) {
207 		/* DMA failed, fall back to PIO */
208 		renesas_sdhi_sys_dmac_enable_dma(host, false);
209 		if (ret >= 0)
210 			ret = -EIO;
211 		host->chan_rx = NULL;
212 		dma_release_channel(chan);
213 		/* Free the Tx channel too */
214 		chan = host->chan_tx;
215 		if (chan) {
216 			host->chan_tx = NULL;
217 			dma_release_channel(chan);
218 		}
219 		dev_warn(&host->pdev->dev,
220 			 "DMA failed: %d, falling back to PIO\n", ret);
221 	}
222 }
223 
224 static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
225 {
226 	struct renesas_sdhi *priv = host_to_priv(host);
227 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
228 	struct dma_async_tx_descriptor *desc = NULL;
229 	struct dma_chan *chan = host->chan_tx;
230 	dma_cookie_t cookie;
231 	int ret, i;
232 	bool aligned = true, multiple = true;
233 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
234 
235 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
236 		if (sg_tmp->offset & align)
237 			aligned = false;
238 		if (sg_tmp->length & align) {
239 			multiple = false;
240 			break;
241 		}
242 	}
243 
244 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
245 			  (align & PAGE_MASK))) || !multiple) {
246 		ret = -EINVAL;
247 		goto pio;
248 	}
249 
250 	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
251 		return;
252 
253 	/* The only sg element can be unaligned, use our bounce buffer then */
254 	if (!aligned) {
255 		unsigned long flags;
256 		void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
257 
258 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
259 		memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
260 		tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
261 		host->sg_ptr = &host->bounce_sg;
262 		sg = host->sg_ptr;
263 	}
264 
265 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
266 	if (ret > 0)
267 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_MEM_TO_DEV,
268 					       DMA_CTRL_ACK);
269 
270 	if (desc) {
271 		reinit_completion(&priv->dma_priv.dma_dataend);
272 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
273 		desc->callback_param = host;
274 
275 		cookie = dmaengine_submit(desc);
276 		if (cookie < 0) {
277 			desc = NULL;
278 			ret = cookie;
279 		}
280 		host->dma_on = true;
281 	}
282 pio:
283 	if (!desc) {
284 		/* DMA failed, fall back to PIO */
285 		renesas_sdhi_sys_dmac_enable_dma(host, false);
286 		if (ret >= 0)
287 			ret = -EIO;
288 		host->chan_tx = NULL;
289 		dma_release_channel(chan);
290 		/* Free the Rx channel too */
291 		chan = host->chan_rx;
292 		if (chan) {
293 			host->chan_rx = NULL;
294 			dma_release_channel(chan);
295 		}
296 		dev_warn(&host->pdev->dev,
297 			 "DMA failed: %d, falling back to PIO\n", ret);
298 	}
299 }
300 
301 static void renesas_sdhi_sys_dmac_start_dma(struct tmio_mmc_host *host,
302 					    struct mmc_data *data)
303 {
304 	if (data->flags & MMC_DATA_READ) {
305 		if (host->chan_rx)
306 			renesas_sdhi_sys_dmac_start_dma_rx(host);
307 	} else {
308 		if (host->chan_tx)
309 			renesas_sdhi_sys_dmac_start_dma_tx(host);
310 	}
311 }
312 
313 static void renesas_sdhi_sys_dmac_issue_tasklet_fn(unsigned long priv)
314 {
315 	struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
316 	struct dma_chan *chan = NULL;
317 
318 	spin_lock_irq(&host->lock);
319 
320 	if (host->data) {
321 		if (host->data->flags & MMC_DATA_READ)
322 			chan = host->chan_rx;
323 		else
324 			chan = host->chan_tx;
325 	}
326 
327 	spin_unlock_irq(&host->lock);
328 
329 	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
330 
331 	if (chan)
332 		dma_async_issue_pending(chan);
333 }
334 
335 static void renesas_sdhi_sys_dmac_request_dma(struct tmio_mmc_host *host,
336 					      struct tmio_mmc_data *pdata)
337 {
338 	struct renesas_sdhi *priv = host_to_priv(host);
339 
340 	/* We can only either use DMA for both Tx and Rx or not use it at all */
341 	if (!host->pdev->dev.of_node &&
342 	    (!pdata->chan_priv_tx || !pdata->chan_priv_rx))
343 		return;
344 
345 	if (!host->chan_tx && !host->chan_rx) {
346 		struct resource *res = platform_get_resource(host->pdev,
347 							     IORESOURCE_MEM, 0);
348 		struct dma_slave_config cfg = {};
349 		dma_cap_mask_t mask;
350 		int ret;
351 
352 		if (!res)
353 			return;
354 
355 		dma_cap_zero(mask);
356 		dma_cap_set(DMA_SLAVE, mask);
357 
358 		host->chan_tx = dma_request_slave_channel_compat(mask,
359 					priv->dma_priv.filter, pdata->chan_priv_tx,
360 					&host->pdev->dev, "tx");
361 		dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
362 			host->chan_tx);
363 
364 		if (!host->chan_tx)
365 			return;
366 
367 		cfg.direction = DMA_MEM_TO_DEV;
368 		cfg.dst_addr = res->start +
369 			(CTL_SD_DATA_PORT << host->bus_shift);
370 		cfg.dst_addr_width = priv->dma_priv.dma_buswidth;
371 		if (!cfg.dst_addr_width)
372 			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
373 		cfg.src_addr = 0;
374 		ret = dmaengine_slave_config(host->chan_tx, &cfg);
375 		if (ret < 0)
376 			goto ecfgtx;
377 
378 		host->chan_rx = dma_request_slave_channel_compat(mask,
379 					priv->dma_priv.filter, pdata->chan_priv_rx,
380 					&host->pdev->dev, "rx");
381 		dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
382 			host->chan_rx);
383 
384 		if (!host->chan_rx)
385 			goto ereqrx;
386 
387 		cfg.direction = DMA_DEV_TO_MEM;
388 		cfg.src_addr = cfg.dst_addr + host->pdata->dma_rx_offset;
389 		cfg.src_addr_width = priv->dma_priv.dma_buswidth;
390 		if (!cfg.src_addr_width)
391 			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
392 		cfg.dst_addr = 0;
393 		ret = dmaengine_slave_config(host->chan_rx, &cfg);
394 		if (ret < 0)
395 			goto ecfgrx;
396 
397 		host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
398 		if (!host->bounce_buf)
399 			goto ebouncebuf;
400 
401 		init_completion(&priv->dma_priv.dma_dataend);
402 		tasklet_init(&host->dma_issue,
403 			     renesas_sdhi_sys_dmac_issue_tasklet_fn,
404 			     (unsigned long)host);
405 	}
406 
407 	renesas_sdhi_sys_dmac_enable_dma(host, true);
408 
409 	return;
410 
411 ebouncebuf:
412 ecfgrx:
413 	dma_release_channel(host->chan_rx);
414 	host->chan_rx = NULL;
415 ereqrx:
416 ecfgtx:
417 	dma_release_channel(host->chan_tx);
418 	host->chan_tx = NULL;
419 }
420 
421 static void renesas_sdhi_sys_dmac_release_dma(struct tmio_mmc_host *host)
422 {
423 	if (host->chan_tx) {
424 		struct dma_chan *chan = host->chan_tx;
425 
426 		host->chan_tx = NULL;
427 		dma_release_channel(chan);
428 	}
429 	if (host->chan_rx) {
430 		struct dma_chan *chan = host->chan_rx;
431 
432 		host->chan_rx = NULL;
433 		dma_release_channel(chan);
434 	}
435 	if (host->bounce_buf) {
436 		free_pages((unsigned long)host->bounce_buf, 0);
437 		host->bounce_buf = NULL;
438 	}
439 }
440 
441 static const struct tmio_mmc_dma_ops renesas_sdhi_sys_dmac_dma_ops = {
442 	.start = renesas_sdhi_sys_dmac_start_dma,
443 	.enable = renesas_sdhi_sys_dmac_enable_dma,
444 	.request = renesas_sdhi_sys_dmac_request_dma,
445 	.release = renesas_sdhi_sys_dmac_release_dma,
446 	.abort = renesas_sdhi_sys_dmac_abort_dma,
447 	.dataend = renesas_sdhi_sys_dmac_dataend_dma,
448 };
449 
450 static int renesas_sdhi_sys_dmac_probe(struct platform_device *pdev)
451 {
452 	return renesas_sdhi_probe(pdev, &renesas_sdhi_sys_dmac_dma_ops);
453 }
454 
455 static const struct dev_pm_ops renesas_sdhi_sys_dmac_dev_pm_ops = {
456 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
457 				pm_runtime_force_resume)
458 	SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
459 			   tmio_mmc_host_runtime_resume,
460 			   NULL)
461 };
462 
463 static struct platform_driver renesas_sys_dmac_sdhi_driver = {
464 	.driver		= {
465 		.name	= "sh_mobile_sdhi",
466 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
467 		.pm	= &renesas_sdhi_sys_dmac_dev_pm_ops,
468 		.of_match_table = renesas_sdhi_sys_dmac_of_match,
469 	},
470 	.probe		= renesas_sdhi_sys_dmac_probe,
471 	.remove		= renesas_sdhi_remove,
472 };
473 
474 module_platform_driver(renesas_sys_dmac_sdhi_driver);
475 
476 MODULE_DESCRIPTION("Renesas SDHI driver");
477 MODULE_AUTHOR("Magnus Damm");
478 MODULE_LICENSE("GPL v2");
479 MODULE_ALIAS("platform:sh_mobile_sdhi");
480