1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Freescale eSDHC ColdFire family controller driver, platform bus.
4  *
5  * Copyright (c) 2020 Timesys Corporation
6  *   Author: Angelo Dureghello <angelo.dureghello@timesys.it>
7  */
8 
9 #include <linux/module.h>
10 #include <linux/delay.h>
11 #include <linux/platform_data/mmc-esdhc-mcf.h>
12 #include <linux/mmc/mmc.h>
13 #include "sdhci-pltfm.h"
14 #include "sdhci-esdhc.h"
15 
16 #define	ESDHC_PROCTL_D3CD		0x08
17 #define ESDHC_SYS_CTRL_DTOCV_MASK	0x0f
18 #define ESDHC_DEFAULT_HOST_CONTROL	0x28
19 
20 /*
21  * Freescale eSDHC has DMA ERR flag at bit 28, not as std spec says, bit 25.
22  */
23 #define ESDHC_INT_VENDOR_SPEC_DMA_ERR	BIT(28)
24 
25 struct pltfm_mcf_data {
26 	struct clk *clk_ipg;
27 	struct clk *clk_ahb;
28 	struct clk *clk_per;
29 	int aside;
30 	int current_bus_width;
31 };
32 
33 static inline void esdhc_mcf_buffer_swap32(u32 *buf, int len)
34 {
35 	int i;
36 	u32 temp;
37 
38 	len = (len + 3) >> 2;
39 
40 	for (i = 0; i < len;  i++) {
41 		temp = swab32(*buf);
42 		*buf++ = temp;
43 	}
44 }
45 
46 static inline void esdhc_clrset_be(struct sdhci_host *host,
47 				   u32 mask, u32 val, int reg)
48 {
49 	void __iomem *base = host->ioaddr + (reg & ~3);
50 	u8 shift = (reg & 3) << 3;
51 
52 	mask <<= shift;
53 	val <<= shift;
54 
55 	if (reg == SDHCI_HOST_CONTROL)
56 		val |= ESDHC_PROCTL_D3CD;
57 
58 	writel((readl(base) & ~mask) | val, base);
59 }
60 
61 /*
62  * Note: mcf is big-endian, single bytes need to be accessed at big endian
63  * offsets.
64  */
65 static void esdhc_mcf_writeb_be(struct sdhci_host *host, u8 val, int reg)
66 {
67 	void __iomem *base = host->ioaddr + (reg & ~3);
68 	u8 shift = (reg & 3) << 3;
69 	u32 mask = ~(0xff << shift);
70 
71 	if (reg == SDHCI_HOST_CONTROL) {
72 		u32 host_ctrl = ESDHC_DEFAULT_HOST_CONTROL;
73 		u8 dma_bits = (val & SDHCI_CTRL_DMA_MASK) >> 3;
74 		u8 tmp = readb(host->ioaddr + SDHCI_HOST_CONTROL + 1);
75 
76 		tmp &= ~0x03;
77 		tmp |= dma_bits;
78 
79 		/*
80 		 * Recomposition needed, restore always endianness and
81 		 * keep D3CD and AI, just setting bus width.
82 		 */
83 		host_ctrl |= val;
84 		host_ctrl |= (dma_bits << 8);
85 		writel(host_ctrl, host->ioaddr + SDHCI_HOST_CONTROL);
86 
87 		return;
88 	}
89 
90 	writel((readl(base) & mask) | (val << shift), base);
91 }
92 
93 static void esdhc_mcf_writew_be(struct sdhci_host *host, u16 val, int reg)
94 {
95 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
96 	struct pltfm_mcf_data *mcf_data = sdhci_pltfm_priv(pltfm_host);
97 	void __iomem *base = host->ioaddr + (reg & ~3);
98 	u8 shift = (reg & 3) << 3;
99 	u32 mask = ~(0xffff << shift);
100 
101 	switch (reg) {
102 	case SDHCI_TRANSFER_MODE:
103 		mcf_data->aside = val;
104 		return;
105 	case SDHCI_COMMAND:
106 		if (host->cmd->opcode == MMC_STOP_TRANSMISSION)
107 			val |= SDHCI_CMD_ABORTCMD;
108 
109 		/*
110 		 * As for the fsl driver,
111 		 * we have to set the mode in a single write here.
112 		 */
113 		writel(val << 16 | mcf_data->aside,
114 		       host->ioaddr + SDHCI_TRANSFER_MODE);
115 		return;
116 	}
117 
118 	writel((readl(base) & mask) | (val << shift), base);
119 }
120 
121 static void esdhc_mcf_writel_be(struct sdhci_host *host, u32 val, int reg)
122 {
123 	writel(val, host->ioaddr + reg);
124 }
125 
126 static u8 esdhc_mcf_readb_be(struct sdhci_host *host, int reg)
127 {
128 	if (reg == SDHCI_HOST_CONTROL) {
129 		u8 __iomem *base = host->ioaddr + (reg & ~3);
130 		u16 val = readw(base + 2);
131 		u8 dma_bits = (val >> 5) & SDHCI_CTRL_DMA_MASK;
132 		u8 host_ctrl = val & 0xff;
133 
134 		host_ctrl &= ~SDHCI_CTRL_DMA_MASK;
135 		host_ctrl |= dma_bits;
136 
137 		return host_ctrl;
138 	}
139 
140 	return readb(host->ioaddr + (reg ^ 0x3));
141 }
142 
143 static u16 esdhc_mcf_readw_be(struct sdhci_host *host, int reg)
144 {
145 	/*
146 	 * For SDHCI_HOST_VERSION, sdhci specs defines 0xFE,
147 	 * a wrong offset for us, we are at 0xFC.
148 	 */
149 	if (reg == SDHCI_HOST_VERSION)
150 		reg -= 2;
151 
152 	return readw(host->ioaddr + (reg ^ 0x2));
153 }
154 
155 static u32 esdhc_mcf_readl_be(struct sdhci_host *host, int reg)
156 {
157 	u32 val;
158 
159 	val = readl(host->ioaddr + reg);
160 
161 	/*
162 	 * RM (25.3.9) sd pin clock must never exceed 25Mhz.
163 	 * So forcing legacy mode at 25Mhz.
164 	 */
165 	if (unlikely(reg == SDHCI_CAPABILITIES))
166 		val &= ~SDHCI_CAN_DO_HISPD;
167 
168 	if (unlikely(reg == SDHCI_INT_STATUS)) {
169 		if (val & ESDHC_INT_VENDOR_SPEC_DMA_ERR) {
170 			val &= ~ESDHC_INT_VENDOR_SPEC_DMA_ERR;
171 			val |= SDHCI_INT_ADMA_ERROR;
172 		}
173 	}
174 
175 	return val;
176 }
177 
178 static unsigned int esdhc_mcf_get_max_timeout_count(struct sdhci_host *host)
179 {
180 	return 1 << 27;
181 }
182 
183 static void esdhc_mcf_set_timeout(struct sdhci_host *host,
184 				  struct mmc_command *cmd)
185 {
186 	/* Use maximum timeout counter */
187 	esdhc_clrset_be(host, ESDHC_SYS_CTRL_DTOCV_MASK, 0xE,
188 			SDHCI_TIMEOUT_CONTROL);
189 }
190 
191 static void esdhc_mcf_reset(struct sdhci_host *host, u8 mask)
192 {
193 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
194 	struct pltfm_mcf_data *mcf_data = sdhci_pltfm_priv(pltfm_host);
195 
196 	sdhci_reset(host, mask);
197 
198 	esdhc_clrset_be(host, ESDHC_CTRL_BUSWIDTH_MASK,
199 			mcf_data->current_bus_width, SDHCI_HOST_CONTROL);
200 
201 	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
202 	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
203 }
204 
205 static unsigned int esdhc_mcf_pltfm_get_max_clock(struct sdhci_host *host)
206 {
207 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
208 
209 	return pltfm_host->clock;
210 }
211 
212 static unsigned int esdhc_mcf_pltfm_get_min_clock(struct sdhci_host *host)
213 {
214 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
215 
216 	return pltfm_host->clock / 256 / 16;
217 }
218 
219 static void esdhc_mcf_pltfm_set_clock(struct sdhci_host *host,
220 				      unsigned int clock)
221 {
222 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
223 	unsigned long *pll_dr = (unsigned long *)MCF_PLL_DR;
224 	u32 fvco, fsys, fesdhc, temp;
225 	const int sdclkfs[] = {2, 4, 8, 16, 32, 64, 128, 256};
226 	int delta, old_delta = clock;
227 	int i, q, ri, rq;
228 
229 	if (clock == 0) {
230 		host->mmc->actual_clock = 0;
231 		return;
232 	}
233 
234 	/*
235 	 * ColdFire eSDHC clock.s
236 	 *
237 	 * pll -+-> / outdiv1 --> fsys
238 	 *      +-> / outdiv3 --> eSDHC clock ---> / SDCCLKFS / DVS
239 	 *
240 	 * mcf5441x datasheet says:
241 	 * (8.1.2) eSDHC should be 40 MHz max
242 	 * (25.3.9) eSDHC input is, as example, 96 Mhz ...
243 	 * (25.3.9) sd pin clock must never exceed 25Mhz
244 	 *
245 	 * fvco = fsys * outdvi1 + 1
246 	 * fshdc = fvco / outdiv3 + 1
247 	 */
248 	temp = readl(pll_dr);
249 	fsys = pltfm_host->clock;
250 	fvco = fsys * ((temp & 0x1f) + 1);
251 	fesdhc = fvco / (((temp >> 10) & 0x1f) + 1);
252 
253 	for (i = 0; i < 8; ++i) {
254 		int result = fesdhc / sdclkfs[i];
255 
256 		for (q = 1; q < 17; ++q) {
257 			int finale = result / q;
258 
259 			delta = abs(clock - finale);
260 
261 			if (delta < old_delta) {
262 				old_delta = delta;
263 				ri = i;
264 				rq = q;
265 			}
266 		}
267 	}
268 
269 	/*
270 	 * Apply divisors and re-enable all the clocks
271 	 */
272 	temp = ((sdclkfs[ri] >> 1) << 8) | ((rq - 1) << 4) |
273 		(ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN);
274 	esdhc_clrset_be(host, 0x0000fff7, temp, SDHCI_CLOCK_CONTROL);
275 
276 	host->mmc->actual_clock = clock;
277 
278 	mdelay(1);
279 }
280 
281 static void esdhc_mcf_pltfm_set_bus_width(struct sdhci_host *host, int width)
282 {
283 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
284 	struct pltfm_mcf_data *mcf_data = sdhci_pltfm_priv(pltfm_host);
285 
286 	switch (width) {
287 	case MMC_BUS_WIDTH_4:
288 		mcf_data->current_bus_width = ESDHC_CTRL_4BITBUS;
289 		break;
290 	default:
291 		mcf_data->current_bus_width = 0;
292 		break;
293 	}
294 
295 	esdhc_clrset_be(host, ESDHC_CTRL_BUSWIDTH_MASK,
296 			mcf_data->current_bus_width, SDHCI_HOST_CONTROL);
297 }
298 
299 static void esdhc_mcf_request_done(struct sdhci_host *host,
300 				   struct mmc_request *mrq)
301 {
302 	struct scatterlist *sg;
303 	u32 *buffer;
304 	int i;
305 
306 	if (!mrq->data || !mrq->data->bytes_xfered)
307 		goto exit_done;
308 
309 	if (mmc_get_dma_dir(mrq->data) != DMA_FROM_DEVICE)
310 		goto exit_done;
311 
312 	/*
313 	 * On mcf5441x there is no hw sdma option/flag to select the dma
314 	 * transfer endiannes. A swap after the transfer is needed.
315 	 */
316 	for_each_sg(mrq->data->sg, sg, mrq->data->sg_len, i) {
317 		buffer = (u32 *)sg_virt(sg);
318 		esdhc_mcf_buffer_swap32(buffer, sg->length);
319 	}
320 
321 exit_done:
322 	mmc_request_done(host->mmc, mrq);
323 }
324 
325 static void esdhc_mcf_copy_to_bounce_buffer(struct sdhci_host *host,
326 					    struct mmc_data *data,
327 					    unsigned int length)
328 {
329 	sg_copy_to_buffer(data->sg, data->sg_len,
330 			  host->bounce_buffer, length);
331 
332 	esdhc_mcf_buffer_swap32((u32 *)host->bounce_buffer,
333 				data->blksz * data->blocks);
334 }
335 
336 static struct sdhci_ops sdhci_esdhc_ops = {
337 	.reset = esdhc_mcf_reset,
338 	.set_clock = esdhc_mcf_pltfm_set_clock,
339 	.get_max_clock = esdhc_mcf_pltfm_get_max_clock,
340 	.get_min_clock = esdhc_mcf_pltfm_get_min_clock,
341 	.set_bus_width = esdhc_mcf_pltfm_set_bus_width,
342 	.get_max_timeout_count = esdhc_mcf_get_max_timeout_count,
343 	.set_timeout = esdhc_mcf_set_timeout,
344 	.write_b = esdhc_mcf_writeb_be,
345 	.write_w = esdhc_mcf_writew_be,
346 	.write_l = esdhc_mcf_writel_be,
347 	.read_b = esdhc_mcf_readb_be,
348 	.read_w = esdhc_mcf_readw_be,
349 	.read_l = esdhc_mcf_readl_be,
350 	.copy_to_bounce_buffer = esdhc_mcf_copy_to_bounce_buffer,
351 	.request_done = esdhc_mcf_request_done,
352 };
353 
354 static const struct sdhci_pltfm_data sdhci_esdhc_mcf_pdata = {
355 	.ops = &sdhci_esdhc_ops,
356 	.quirks = ESDHC_DEFAULT_QUIRKS | SDHCI_QUIRK_FORCE_DMA,
357 		 /*
358 		  * Mandatory quirk,
359 		  * controller does not support cmd23,
360 		  * without, on > 8G cards cmd23 is used, and
361 		  * driver times out.
362 		  */
363 		  SDHCI_QUIRK2_HOST_NO_CMD23,
364 };
365 
366 static int esdhc_mcf_plat_init(struct sdhci_host *host,
367 			       struct pltfm_mcf_data *mcf_data)
368 {
369 	struct mcf_esdhc_platform_data *plat_data;
370 	struct device *dev = mmc_dev(host->mmc);
371 
372 	if (!dev->platform_data) {
373 		dev_err(dev, "no platform data!\n");
374 		return -EINVAL;
375 	}
376 
377 	plat_data = (struct mcf_esdhc_platform_data *)dev->platform_data;
378 
379 	/* Card_detect */
380 	switch (plat_data->cd_type) {
381 	default:
382 	case ESDHC_CD_CONTROLLER:
383 		/* We have a working card_detect back */
384 		host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
385 		break;
386 	case ESDHC_CD_PERMANENT:
387 		host->mmc->caps |= MMC_CAP_NONREMOVABLE;
388 		break;
389 	case ESDHC_CD_NONE:
390 		break;
391 	}
392 
393 	switch (plat_data->max_bus_width) {
394 	case 4:
395 		host->mmc->caps |= MMC_CAP_4_BIT_DATA;
396 		break;
397 	case 1:
398 	default:
399 		host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA;
400 		break;
401 	}
402 
403 	return 0;
404 }
405 
406 static int sdhci_esdhc_mcf_probe(struct platform_device *pdev)
407 {
408 	struct sdhci_host *host;
409 	struct sdhci_pltfm_host *pltfm_host;
410 	struct pltfm_mcf_data *mcf_data;
411 	int err;
412 
413 	host = sdhci_pltfm_init(pdev, &sdhci_esdhc_mcf_pdata,
414 				sizeof(*mcf_data));
415 
416 	if (IS_ERR(host))
417 		return PTR_ERR(host);
418 
419 	pltfm_host = sdhci_priv(host);
420 	mcf_data = sdhci_pltfm_priv(pltfm_host);
421 
422 	host->sdma_boundary = 0;
423 
424 	host->flags |= SDHCI_AUTO_CMD12;
425 
426 	mcf_data->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
427 	if (IS_ERR(mcf_data->clk_ipg)) {
428 		err = PTR_ERR(mcf_data->clk_ipg);
429 		goto err_exit;
430 	}
431 
432 	mcf_data->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
433 	if (IS_ERR(mcf_data->clk_ahb)) {
434 		err = PTR_ERR(mcf_data->clk_ahb);
435 		goto err_exit;
436 	}
437 
438 	mcf_data->clk_per = devm_clk_get(&pdev->dev, "per");
439 	if (IS_ERR(mcf_data->clk_per)) {
440 		err = PTR_ERR(mcf_data->clk_per);
441 		goto err_exit;
442 	}
443 
444 	pltfm_host->clk = mcf_data->clk_per;
445 	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
446 	err = clk_prepare_enable(mcf_data->clk_per);
447 	if (err)
448 		goto err_exit;
449 
450 	err = clk_prepare_enable(mcf_data->clk_ipg);
451 	if (err)
452 		goto unprep_per;
453 
454 	err = clk_prepare_enable(mcf_data->clk_ahb);
455 	if (err)
456 		goto unprep_ipg;
457 
458 	err = esdhc_mcf_plat_init(host, mcf_data);
459 	if (err)
460 		goto unprep_ahb;
461 
462 	err = sdhci_setup_host(host);
463 	if (err)
464 		goto unprep_ahb;
465 
466 	if (!host->bounce_buffer) {
467 		dev_err(&pdev->dev, "bounce buffer not allocated");
468 		err = -ENOMEM;
469 		goto cleanup;
470 	}
471 
472 	err = __sdhci_add_host(host);
473 	if (err)
474 		goto cleanup;
475 
476 	return 0;
477 
478 cleanup:
479 	sdhci_cleanup_host(host);
480 unprep_ahb:
481 	clk_disable_unprepare(mcf_data->clk_ahb);
482 unprep_ipg:
483 	clk_disable_unprepare(mcf_data->clk_ipg);
484 unprep_per:
485 	clk_disable_unprepare(mcf_data->clk_per);
486 err_exit:
487 	sdhci_pltfm_free(pdev);
488 
489 	return err;
490 }
491 
492 static void sdhci_esdhc_mcf_remove(struct platform_device *pdev)
493 {
494 	struct sdhci_host *host = platform_get_drvdata(pdev);
495 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
496 	struct pltfm_mcf_data *mcf_data = sdhci_pltfm_priv(pltfm_host);
497 
498 	sdhci_remove_host(host, 0);
499 
500 	clk_disable_unprepare(mcf_data->clk_ipg);
501 	clk_disable_unprepare(mcf_data->clk_ahb);
502 	clk_disable_unprepare(mcf_data->clk_per);
503 
504 	sdhci_pltfm_free(pdev);
505 }
506 
507 static struct platform_driver sdhci_esdhc_mcf_driver = {
508 	.driver	= {
509 		.name = "sdhci-esdhc-mcf",
510 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
511 	},
512 	.probe = sdhci_esdhc_mcf_probe,
513 	.remove_new = sdhci_esdhc_mcf_remove,
514 };
515 
516 module_platform_driver(sdhci_esdhc_mcf_driver);
517 
518 MODULE_DESCRIPTION("SDHCI driver for Freescale ColdFire eSDHC");
519 MODULE_AUTHOR("Angelo Dureghello <angelo.dureghello@timesys.com>");
520 MODULE_LICENSE("GPL v2");
521