xref: /openbmc/linux/drivers/mmc/host/sdhci-st.c (revision 293d5b43)
1 /*
2  * Support for SDHCI on STMicroelectronics SoCs
3  *
4  * Copyright (C) 2014 STMicroelectronics Ltd
5  * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
6  * Contributors: Peter Griffin <peter.griffin@linaro.org>
7  *
8  * Based on sdhci-cns3xxx.c
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  */
20 
21 #include <linux/io.h>
22 #include <linux/of.h>
23 #include <linux/module.h>
24 #include <linux/err.h>
25 #include <linux/mmc/host.h>
26 #include <linux/reset.h>
27 #include "sdhci-pltfm.h"
28 
29 struct st_mmc_platform_data {
30 	struct  reset_control *rstc;
31 	void __iomem *top_ioaddr;
32 };
33 
34 /* MMCSS glue logic to setup the HC on some ST SoCs (e.g. STiH407 family) */
35 
36 #define ST_MMC_CCONFIG_REG_1		0x400
37 #define ST_MMC_CCONFIG_TIMEOUT_CLK_UNIT	BIT(24)
38 #define ST_MMC_CCONFIG_TIMEOUT_CLK_FREQ	BIT(12)
39 #define ST_MMC_CCONFIG_TUNING_COUNT_DEFAULT	BIT(8)
40 #define ST_MMC_CCONFIG_ASYNC_WAKEUP	BIT(0)
41 #define ST_MMC_CCONFIG_1_DEFAULT	\
42 				((ST_MMC_CCONFIG_TIMEOUT_CLK_UNIT) | \
43 				 (ST_MMC_CCONFIG_TIMEOUT_CLK_FREQ) | \
44 				 (ST_MMC_CCONFIG_TUNING_COUNT_DEFAULT))
45 
46 #define ST_MMC_CCONFIG_REG_2		0x404
47 #define ST_MMC_CCONFIG_HIGH_SPEED	BIT(28)
48 #define ST_MMC_CCONFIG_ADMA2		BIT(24)
49 #define ST_MMC_CCONFIG_8BIT		BIT(20)
50 #define ST_MMC_CCONFIG_MAX_BLK_LEN	16
51 #define  MAX_BLK_LEN_1024		1
52 #define  MAX_BLK_LEN_2048		2
53 #define BASE_CLK_FREQ_200		0xc8
54 #define BASE_CLK_FREQ_100		0x64
55 #define BASE_CLK_FREQ_50		0x32
56 #define ST_MMC_CCONFIG_2_DEFAULT \
57 	(ST_MMC_CCONFIG_HIGH_SPEED | ST_MMC_CCONFIG_ADMA2 | \
58 	 ST_MMC_CCONFIG_8BIT | \
59 	 (MAX_BLK_LEN_1024 << ST_MMC_CCONFIG_MAX_BLK_LEN))
60 
61 #define ST_MMC_CCONFIG_REG_3			0x408
62 #define ST_MMC_CCONFIG_EMMC_SLOT_TYPE		BIT(28)
63 #define ST_MMC_CCONFIG_64BIT			BIT(24)
64 #define ST_MMC_CCONFIG_ASYNCH_INTR_SUPPORT	BIT(20)
65 #define ST_MMC_CCONFIG_1P8_VOLT			BIT(16)
66 #define ST_MMC_CCONFIG_3P0_VOLT			BIT(12)
67 #define ST_MMC_CCONFIG_3P3_VOLT			BIT(8)
68 #define ST_MMC_CCONFIG_SUSP_RES_SUPPORT		BIT(4)
69 #define ST_MMC_CCONFIG_SDMA			BIT(0)
70 #define ST_MMC_CCONFIG_3_DEFAULT	\
71 			 (ST_MMC_CCONFIG_ASYNCH_INTR_SUPPORT	| \
72 			  ST_MMC_CCONFIG_3P3_VOLT		| \
73 			  ST_MMC_CCONFIG_SUSP_RES_SUPPORT	| \
74 			  ST_MMC_CCONFIG_SDMA)
75 
76 #define ST_MMC_CCONFIG_REG_4	0x40c
77 #define ST_MMC_CCONFIG_D_DRIVER	BIT(20)
78 #define ST_MMC_CCONFIG_C_DRIVER	BIT(16)
79 #define ST_MMC_CCONFIG_A_DRIVER	BIT(12)
80 #define ST_MMC_CCONFIG_DDR50	BIT(8)
81 #define ST_MMC_CCONFIG_SDR104	BIT(4)
82 #define ST_MMC_CCONFIG_SDR50	BIT(0)
83 #define ST_MMC_CCONFIG_4_DEFAULT	0
84 
85 #define ST_MMC_CCONFIG_REG_5		0x410
86 #define ST_MMC_CCONFIG_TUNING_FOR_SDR50	BIT(8)
87 #define RETUNING_TIMER_CNT_MAX		0xf
88 #define ST_MMC_CCONFIG_5_DEFAULT	0
89 
90 /* I/O configuration for Arasan IP */
91 #define ST_MMC_GP_OUTPUT	0x450
92 #define ST_MMC_GP_OUTPUT_CD	BIT(12)
93 
94 #define ST_MMC_STATUS_R		0x460
95 
96 #define ST_TOP_MMC_DLY_FIX_OFF(x)	(x - 0x8)
97 
98 /* TOP config registers to manage static and dynamic delay */
99 #define ST_TOP_MMC_TX_CLK_DLY			ST_TOP_MMC_DLY_FIX_OFF(0x8)
100 #define ST_TOP_MMC_RX_CLK_DLY			ST_TOP_MMC_DLY_FIX_OFF(0xc)
101 /* MMC delay control register */
102 #define ST_TOP_MMC_DLY_CTRL			ST_TOP_MMC_DLY_FIX_OFF(0x18)
103 #define ST_TOP_MMC_DLY_CTRL_DLL_BYPASS_CMD	BIT(0)
104 #define ST_TOP_MMC_DLY_CTRL_DLL_BYPASS_PH_SEL	BIT(1)
105 #define ST_TOP_MMC_DLY_CTRL_TX_DLL_ENABLE	BIT(8)
106 #define ST_TOP_MMC_DLY_CTRL_RX_DLL_ENABLE	BIT(9)
107 #define ST_TOP_MMC_DLY_CTRL_ATUNE_NOT_CFG_DLY	BIT(10)
108 #define ST_TOP_MMC_START_DLL_LOCK		BIT(11)
109 
110 /* register to provide the phase-shift value for DLL */
111 #define ST_TOP_MMC_TX_DLL_STEP_DLY		ST_TOP_MMC_DLY_FIX_OFF(0x1c)
112 #define ST_TOP_MMC_RX_DLL_STEP_DLY		ST_TOP_MMC_DLY_FIX_OFF(0x20)
113 #define ST_TOP_MMC_RX_CMD_STEP_DLY		ST_TOP_MMC_DLY_FIX_OFF(0x24)
114 
115 /* phase shift delay on the tx clk 2.188ns */
116 #define ST_TOP_MMC_TX_DLL_STEP_DLY_VALID	0x6
117 
118 #define ST_TOP_MMC_DLY_MAX			0xf
119 
120 #define ST_TOP_MMC_DYN_DLY_CONF	\
121 		(ST_TOP_MMC_DLY_CTRL_TX_DLL_ENABLE | \
122 		 ST_TOP_MMC_DLY_CTRL_ATUNE_NOT_CFG_DLY | \
123 		 ST_TOP_MMC_START_DLL_LOCK)
124 
125 /*
126  * For clock speeds greater than 90MHz, we need to check that the
127  * DLL procedure has finished before switching to ultra-speed modes.
128  */
129 #define	CLK_TO_CHECK_DLL_LOCK	90000000
130 
131 static inline void st_mmcss_set_static_delay(void __iomem *ioaddr)
132 {
133 	if (!ioaddr)
134 		return;
135 
136 	writel_relaxed(0x0, ioaddr + ST_TOP_MMC_DLY_CTRL);
137 	writel_relaxed(ST_TOP_MMC_DLY_MAX,
138 			ioaddr + ST_TOP_MMC_TX_CLK_DLY);
139 }
140 
141 /**
142  * st_mmcss_cconfig: configure the Arasan HC inside the flashSS.
143  * @np: dt device node.
144  * @host: sdhci host
145  * Description: this function is to configure the Arasan host controller.
146  * On some ST SoCs, i.e. STiH407 family, the MMC devices inside a dedicated
147  * flashSS sub-system which needs to be configured to be compliant to eMMC 4.5
148  * or eMMC4.3.  This has to be done before registering the sdhci host.
149  */
150 static void st_mmcss_cconfig(struct device_node *np, struct sdhci_host *host)
151 {
152 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
153 	struct mmc_host *mhost = host->mmc;
154 	u32 cconf2, cconf3, cconf4, cconf5;
155 
156 	if (!of_device_is_compatible(np, "st,sdhci-stih407"))
157 		return;
158 
159 	cconf2 = ST_MMC_CCONFIG_2_DEFAULT;
160 	cconf3 = ST_MMC_CCONFIG_3_DEFAULT;
161 	cconf4 = ST_MMC_CCONFIG_4_DEFAULT;
162 	cconf5 = ST_MMC_CCONFIG_5_DEFAULT;
163 
164 	writel_relaxed(ST_MMC_CCONFIG_1_DEFAULT,
165 			host->ioaddr + ST_MMC_CCONFIG_REG_1);
166 
167 	/* Set clock frequency, default to 50MHz if max-frequency is not
168 	 * provided */
169 
170 	switch (mhost->f_max) {
171 	case 200000000:
172 		clk_set_rate(pltfm_host->clk, mhost->f_max);
173 		cconf2 |= BASE_CLK_FREQ_200;
174 		break;
175 	case 100000000:
176 		clk_set_rate(pltfm_host->clk, mhost->f_max);
177 		cconf2 |= BASE_CLK_FREQ_100;
178 		break;
179 	default:
180 		clk_set_rate(pltfm_host->clk, 50000000);
181 		cconf2 |= BASE_CLK_FREQ_50;
182 	}
183 
184 	writel_relaxed(cconf2, host->ioaddr + ST_MMC_CCONFIG_REG_2);
185 
186 	if (!mmc_card_is_removable(mhost))
187 		cconf3 |= ST_MMC_CCONFIG_EMMC_SLOT_TYPE;
188 	else
189 		/* CARD _D ET_CTRL */
190 		writel_relaxed(ST_MMC_GP_OUTPUT_CD,
191 				host->ioaddr + ST_MMC_GP_OUTPUT);
192 
193 	if (mhost->caps & MMC_CAP_UHS_SDR50) {
194 		/* use 1.8V */
195 		cconf3 |= ST_MMC_CCONFIG_1P8_VOLT;
196 		cconf4 |= ST_MMC_CCONFIG_SDR50;
197 		/* Use tuning */
198 		cconf5 |= ST_MMC_CCONFIG_TUNING_FOR_SDR50;
199 		/* Max timeout for retuning */
200 		cconf5 |= RETUNING_TIMER_CNT_MAX;
201 	}
202 
203 	if (mhost->caps & MMC_CAP_UHS_SDR104) {
204 		/*
205 		 * SDR104 implies the HC can support HS200 mode, so
206 		 * it's mandatory to use 1.8V
207 		 */
208 		cconf3 |= ST_MMC_CCONFIG_1P8_VOLT;
209 		cconf4 |= ST_MMC_CCONFIG_SDR104;
210 		/* Max timeout for retuning */
211 		cconf5 |= RETUNING_TIMER_CNT_MAX;
212 	}
213 
214 	if (mhost->caps & MMC_CAP_UHS_DDR50)
215 		cconf4 |= ST_MMC_CCONFIG_DDR50;
216 
217 	writel_relaxed(cconf3, host->ioaddr + ST_MMC_CCONFIG_REG_3);
218 	writel_relaxed(cconf4, host->ioaddr + ST_MMC_CCONFIG_REG_4);
219 	writel_relaxed(cconf5, host->ioaddr + ST_MMC_CCONFIG_REG_5);
220 }
221 
222 static inline void st_mmcss_set_dll(void __iomem *ioaddr)
223 {
224 	if (!ioaddr)
225 		return;
226 
227 	writel_relaxed(ST_TOP_MMC_DYN_DLY_CONF,	ioaddr + ST_TOP_MMC_DLY_CTRL);
228 	writel_relaxed(ST_TOP_MMC_TX_DLL_STEP_DLY_VALID,
229 			ioaddr + ST_TOP_MMC_TX_DLL_STEP_DLY);
230 }
231 
232 static int st_mmcss_lock_dll(void __iomem *ioaddr)
233 {
234 	unsigned long curr, value;
235 	unsigned long finish = jiffies + HZ;
236 
237 	/* Checks if the DLL procedure is finished */
238 	do {
239 		curr = jiffies;
240 		value = readl(ioaddr + ST_MMC_STATUS_R);
241 		if (value & 0x1)
242 			return 0;
243 
244 		cpu_relax();
245 	} while (!time_after_eq(curr, finish));
246 
247 	return -EBUSY;
248 }
249 
250 static int sdhci_st_set_dll_for_clock(struct sdhci_host *host)
251 {
252 	int ret = 0;
253 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
254 	struct st_mmc_platform_data *pdata = sdhci_pltfm_priv(pltfm_host);
255 
256 	if (host->clock > CLK_TO_CHECK_DLL_LOCK) {
257 		st_mmcss_set_dll(pdata->top_ioaddr);
258 		ret = st_mmcss_lock_dll(host->ioaddr);
259 	}
260 
261 	return ret;
262 }
263 
264 static void sdhci_st_set_uhs_signaling(struct sdhci_host *host,
265 					unsigned int uhs)
266 {
267 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
268 	struct st_mmc_platform_data *pdata = sdhci_pltfm_priv(pltfm_host);
269 	u16 ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
270 	int ret = 0;
271 
272 	/* Select Bus Speed Mode for host */
273 	ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
274 	switch (uhs) {
275 	/*
276 	 * Set V18_EN -- UHS modes do not work without this.
277 	 * does not change signaling voltage
278 	 */
279 
280 	case MMC_TIMING_UHS_SDR12:
281 		st_mmcss_set_static_delay(pdata->top_ioaddr);
282 		ctrl_2 |= SDHCI_CTRL_UHS_SDR12 | SDHCI_CTRL_VDD_180;
283 		break;
284 	case MMC_TIMING_UHS_SDR25:
285 		st_mmcss_set_static_delay(pdata->top_ioaddr);
286 		ctrl_2 |= SDHCI_CTRL_UHS_SDR25 | SDHCI_CTRL_VDD_180;
287 		break;
288 	case MMC_TIMING_UHS_SDR50:
289 		st_mmcss_set_static_delay(pdata->top_ioaddr);
290 		ctrl_2 |= SDHCI_CTRL_UHS_SDR50 | SDHCI_CTRL_VDD_180;
291 		ret = sdhci_st_set_dll_for_clock(host);
292 		break;
293 	case MMC_TIMING_UHS_SDR104:
294 	case MMC_TIMING_MMC_HS200:
295 		st_mmcss_set_static_delay(pdata->top_ioaddr);
296 		ctrl_2 |= SDHCI_CTRL_UHS_SDR104 | SDHCI_CTRL_VDD_180;
297 		ret =  sdhci_st_set_dll_for_clock(host);
298 		break;
299 	case MMC_TIMING_UHS_DDR50:
300 	case MMC_TIMING_MMC_DDR52:
301 		st_mmcss_set_static_delay(pdata->top_ioaddr);
302 		ctrl_2 |= SDHCI_CTRL_UHS_DDR50 | SDHCI_CTRL_VDD_180;
303 		break;
304 	}
305 
306 	if (ret)
307 		dev_warn(mmc_dev(host->mmc), "Error setting dll for clock "
308 						"(uhs %d)\n", uhs);
309 
310 	dev_dbg(mmc_dev(host->mmc), "uhs %d, ctrl_2 %04X\n", uhs, ctrl_2);
311 
312 	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
313 }
314 
315 static u32 sdhci_st_readl(struct sdhci_host *host, int reg)
316 {
317 	u32 ret;
318 
319 	switch (reg) {
320 	case SDHCI_CAPABILITIES:
321 		ret = readl_relaxed(host->ioaddr + reg);
322 		/* Support 3.3V and 1.8V */
323 		ret &= ~SDHCI_CAN_VDD_300;
324 		break;
325 	default:
326 		ret = readl_relaxed(host->ioaddr + reg);
327 	}
328 	return ret;
329 }
330 
331 static const struct sdhci_ops sdhci_st_ops = {
332 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
333 	.set_clock = sdhci_set_clock,
334 	.set_bus_width = sdhci_set_bus_width,
335 	.read_l = sdhci_st_readl,
336 	.reset = sdhci_reset,
337 	.set_uhs_signaling = sdhci_st_set_uhs_signaling,
338 };
339 
340 static const struct sdhci_pltfm_data sdhci_st_pdata = {
341 	.ops = &sdhci_st_ops,
342 	.quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC |
343 		SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
344 		SDHCI_QUIRK_NO_HISPD_BIT,
345 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
346 		SDHCI_QUIRK2_STOP_WITH_TC,
347 };
348 
349 
350 static int sdhci_st_probe(struct platform_device *pdev)
351 {
352 	struct device_node *np = pdev->dev.of_node;
353 	struct sdhci_host *host;
354 	struct st_mmc_platform_data *pdata;
355 	struct sdhci_pltfm_host *pltfm_host;
356 	struct clk *clk;
357 	int ret = 0;
358 	u16 host_version;
359 	struct resource *res;
360 	struct reset_control *rstc;
361 
362 	clk =  devm_clk_get(&pdev->dev, "mmc");
363 	if (IS_ERR(clk)) {
364 		dev_err(&pdev->dev, "Peripheral clk not found\n");
365 		return PTR_ERR(clk);
366 	}
367 
368 	rstc = devm_reset_control_get(&pdev->dev, NULL);
369 	if (IS_ERR(rstc))
370 		rstc = NULL;
371 	else
372 		reset_control_deassert(rstc);
373 
374 	host = sdhci_pltfm_init(pdev, &sdhci_st_pdata, sizeof(*pdata));
375 	if (IS_ERR(host)) {
376 		dev_err(&pdev->dev, "Failed sdhci_pltfm_init\n");
377 		ret = PTR_ERR(host);
378 		goto err_pltfm_init;
379 	}
380 
381 	pltfm_host = sdhci_priv(host);
382 	pdata = sdhci_pltfm_priv(pltfm_host);
383 	pdata->rstc = rstc;
384 
385 	ret = mmc_of_parse(host->mmc);
386 	if (ret) {
387 		dev_err(&pdev->dev, "Failed mmc_of_parse\n");
388 		goto err_of;
389 	}
390 
391 	clk_prepare_enable(clk);
392 
393 	/* Configure the FlashSS Top registers for setting eMMC TX/RX delay */
394 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
395 					   "top-mmc-delay");
396 	pdata->top_ioaddr = devm_ioremap_resource(&pdev->dev, res);
397 	if (IS_ERR(pdata->top_ioaddr)) {
398 		dev_warn(&pdev->dev, "FlashSS Top Dly registers not available");
399 		pdata->top_ioaddr = NULL;
400 	}
401 
402 	pltfm_host->clk = clk;
403 
404 	/* Configure the Arasan HC inside the flashSS */
405 	st_mmcss_cconfig(np, host);
406 
407 	ret = sdhci_add_host(host);
408 	if (ret) {
409 		dev_err(&pdev->dev, "Failed sdhci_add_host\n");
410 		goto err_out;
411 	}
412 
413 	platform_set_drvdata(pdev, host);
414 
415 	host_version = readw_relaxed((host->ioaddr + SDHCI_HOST_VERSION));
416 
417 	dev_info(&pdev->dev, "SDHCI ST Initialised: Host Version: 0x%x Vendor Version 0x%x\n",
418 		((host_version & SDHCI_SPEC_VER_MASK) >> SDHCI_SPEC_VER_SHIFT),
419 		((host_version & SDHCI_VENDOR_VER_MASK) >>
420 		SDHCI_VENDOR_VER_SHIFT));
421 
422 	return 0;
423 
424 err_out:
425 	clk_disable_unprepare(clk);
426 err_of:
427 	sdhci_pltfm_free(pdev);
428 err_pltfm_init:
429 	if (rstc)
430 		reset_control_assert(rstc);
431 
432 	return ret;
433 }
434 
435 static int sdhci_st_remove(struct platform_device *pdev)
436 {
437 	struct sdhci_host *host = platform_get_drvdata(pdev);
438 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
439 	struct st_mmc_platform_data *pdata = sdhci_pltfm_priv(pltfm_host);
440 	struct reset_control *rstc = pdata->rstc;
441 	int ret;
442 
443 	ret = sdhci_pltfm_unregister(pdev);
444 
445 	if (rstc)
446 		reset_control_assert(rstc);
447 
448 	return ret;
449 }
450 
451 #ifdef CONFIG_PM_SLEEP
452 static int sdhci_st_suspend(struct device *dev)
453 {
454 	struct sdhci_host *host = dev_get_drvdata(dev);
455 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
456 	struct st_mmc_platform_data *pdata = sdhci_pltfm_priv(pltfm_host);
457 	int ret = sdhci_suspend_host(host);
458 
459 	if (ret)
460 		goto out;
461 
462 	if (pdata->rstc)
463 		reset_control_assert(pdata->rstc);
464 
465 	clk_disable_unprepare(pltfm_host->clk);
466 out:
467 	return ret;
468 }
469 
470 static int sdhci_st_resume(struct device *dev)
471 {
472 	struct sdhci_host *host = dev_get_drvdata(dev);
473 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
474 	struct st_mmc_platform_data *pdata = sdhci_pltfm_priv(pltfm_host);
475 	struct device_node *np = dev->of_node;
476 
477 	clk_prepare_enable(pltfm_host->clk);
478 
479 	if (pdata->rstc)
480 		reset_control_deassert(pdata->rstc);
481 
482 	st_mmcss_cconfig(np, host);
483 
484 	return sdhci_resume_host(host);
485 }
486 #endif
487 
488 static SIMPLE_DEV_PM_OPS(sdhci_st_pmops, sdhci_st_suspend, sdhci_st_resume);
489 
490 static const struct of_device_id st_sdhci_match[] = {
491 	{ .compatible = "st,sdhci" },
492 	{},
493 };
494 
495 MODULE_DEVICE_TABLE(of, st_sdhci_match);
496 
497 static struct platform_driver sdhci_st_driver = {
498 	.probe = sdhci_st_probe,
499 	.remove = sdhci_st_remove,
500 	.driver = {
501 		   .name = "sdhci-st",
502 		   .pm = &sdhci_st_pmops,
503 		   .of_match_table = of_match_ptr(st_sdhci_match),
504 		  },
505 };
506 
507 module_platform_driver(sdhci_st_driver);
508 
509 MODULE_DESCRIPTION("SDHCI driver for STMicroelectronics SoCs");
510 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
511 MODULE_LICENSE("GPL v2");
512 MODULE_ALIAS("platform:sdhci-st");
513