1 /*
2  * Arasan Secure Digital Host Controller Interface.
3  * Copyright (C) 2011 - 2012 Michal Simek <monstr@monstr.eu>
4  * Copyright (c) 2012 Wind River Systems, Inc.
5  * Copyright (C) 2013 Pengutronix e.K.
6  * Copyright (C) 2013 Xilinx Inc.
7  *
8  * Based on sdhci-of-esdhc.c
9  *
10  * Copyright (c) 2007 Freescale Semiconductor, Inc.
11  * Copyright (c) 2009 MontaVista Software, Inc.
12  *
13  * Authors: Xiaobo Xie <X.Xie@freescale.com>
14  *	    Anton Vorontsov <avorontsov@ru.mvista.com>
15  *
16  * This program is free software; you can redistribute it and/or modify
17  * it under the terms of the GNU General Public License as published by
18  * the Free Software Foundation; either version 2 of the License, or (at
19  * your option) any later version.
20  */
21 
22 #include <linux/clk-provider.h>
23 #include <linux/mfd/syscon.h>
24 #include <linux/module.h>
25 #include <linux/of_device.h>
26 #include <linux/phy/phy.h>
27 #include <linux/regmap.h>
28 #include <linux/of.h>
29 
30 #include "cqhci.h"
31 #include "sdhci-pltfm.h"
32 
33 #define SDHCI_ARASAN_VENDOR_REGISTER	0x78
34 #define SDHCI_ARASAN_CQE_BASE_ADDR	0x200
35 #define VENDOR_ENHANCED_STROBE		BIT(0)
36 
37 #define PHY_CLK_TOO_SLOW_HZ		400000
38 
39 /*
40  * On some SoCs the syscon area has a feature where the upper 16-bits of
41  * each 32-bit register act as a write mask for the lower 16-bits.  This allows
42  * atomic updates of the register without locking.  This macro is used on SoCs
43  * that have that feature.
44  */
45 #define HIWORD_UPDATE(val, mask, shift) \
46 		((val) << (shift) | (mask) << ((shift) + 16))
47 
48 /**
49  * struct sdhci_arasan_soc_ctl_field - Field used in sdhci_arasan_soc_ctl_map
50  *
51  * @reg:	Offset within the syscon of the register containing this field
52  * @width:	Number of bits for this field
53  * @shift:	Bit offset within @reg of this field (or -1 if not avail)
54  */
55 struct sdhci_arasan_soc_ctl_field {
56 	u32 reg;
57 	u16 width;
58 	s16 shift;
59 };
60 
61 /**
62  * struct sdhci_arasan_soc_ctl_map - Map in syscon to corecfg registers
63  *
64  * It's up to the licensee of the Arsan IP block to make these available
65  * somewhere if needed.  Presumably these will be scattered somewhere that's
66  * accessible via the syscon API.
67  *
68  * @baseclkfreq:	Where to find corecfg_baseclkfreq
69  * @clockmultiplier:	Where to find corecfg_clockmultiplier
70  * @hiword_update:	If true, use HIWORD_UPDATE to access the syscon
71  */
72 struct sdhci_arasan_soc_ctl_map {
73 	struct sdhci_arasan_soc_ctl_field	baseclkfreq;
74 	struct sdhci_arasan_soc_ctl_field	clockmultiplier;
75 	bool					hiword_update;
76 };
77 
78 /**
79  * struct sdhci_arasan_data
80  * @host:		Pointer to the main SDHCI host structure.
81  * @clk_ahb:		Pointer to the AHB clock
82  * @phy:		Pointer to the generic phy
83  * @is_phy_on:		True if the PHY is on; false if not.
84  * @sdcardclk_hw:	Struct for the clock we might provide to a PHY.
85  * @sdcardclk:		Pointer to normal 'struct clock' for sdcardclk_hw.
86  * @soc_ctl_base:	Pointer to regmap for syscon for soc_ctl registers.
87  * @soc_ctl_map:	Map to get offsets into soc_ctl registers.
88  */
89 struct sdhci_arasan_data {
90 	struct sdhci_host *host;
91 	struct clk	*clk_ahb;
92 	struct phy	*phy;
93 	bool		is_phy_on;
94 
95 	bool		has_cqe;
96 	struct clk_hw	sdcardclk_hw;
97 	struct clk      *sdcardclk;
98 
99 	struct regmap	*soc_ctl_base;
100 	const struct sdhci_arasan_soc_ctl_map *soc_ctl_map;
101 	unsigned int	quirks; /* Arasan deviations from spec */
102 
103 /* Controller does not have CD wired and will not function normally without */
104 #define SDHCI_ARASAN_QUIRK_FORCE_CDTEST	BIT(0)
105 /* Controller immediately reports SDHCI_CLOCK_INT_STABLE after enabling the
106  * internal clock even when the clock isn't stable */
107 #define SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE BIT(1)
108 };
109 
110 static const struct sdhci_arasan_soc_ctl_map rk3399_soc_ctl_map = {
111 	.baseclkfreq = { .reg = 0xf000, .width = 8, .shift = 8 },
112 	.clockmultiplier = { .reg = 0xf02c, .width = 8, .shift = 0},
113 	.hiword_update = true,
114 };
115 
116 /**
117  * sdhci_arasan_syscon_write - Write to a field in soc_ctl registers
118  *
119  * This function allows writing to fields in sdhci_arasan_soc_ctl_map.
120  * Note that if a field is specified as not available (shift < 0) then
121  * this function will silently return an error code.  It will be noisy
122  * and print errors for any other (unexpected) errors.
123  *
124  * @host:	The sdhci_host
125  * @fld:	The field to write to
126  * @val:	The value to write
127  */
128 static int sdhci_arasan_syscon_write(struct sdhci_host *host,
129 				   const struct sdhci_arasan_soc_ctl_field *fld,
130 				   u32 val)
131 {
132 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
133 	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
134 	struct regmap *soc_ctl_base = sdhci_arasan->soc_ctl_base;
135 	u32 reg = fld->reg;
136 	u16 width = fld->width;
137 	s16 shift = fld->shift;
138 	int ret;
139 
140 	/*
141 	 * Silently return errors for shift < 0 so caller doesn't have
142 	 * to check for fields which are optional.  For fields that
143 	 * are required then caller needs to do something special
144 	 * anyway.
145 	 */
146 	if (shift < 0)
147 		return -EINVAL;
148 
149 	if (sdhci_arasan->soc_ctl_map->hiword_update)
150 		ret = regmap_write(soc_ctl_base, reg,
151 				   HIWORD_UPDATE(val, GENMASK(width, 0),
152 						 shift));
153 	else
154 		ret = regmap_update_bits(soc_ctl_base, reg,
155 					 GENMASK(shift + width, shift),
156 					 val << shift);
157 
158 	/* Yell about (unexpected) regmap errors */
159 	if (ret)
160 		pr_warn("%s: Regmap write fail: %d\n",
161 			 mmc_hostname(host->mmc), ret);
162 
163 	return ret;
164 }
165 
166 static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
167 {
168 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
169 	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
170 	bool ctrl_phy = false;
171 
172 	if (!IS_ERR(sdhci_arasan->phy)) {
173 		if (!sdhci_arasan->is_phy_on && clock <= PHY_CLK_TOO_SLOW_HZ) {
174 			/*
175 			 * If PHY off, set clock to max speed and power PHY on.
176 			 *
177 			 * Although PHY docs apparently suggest power cycling
178 			 * when changing the clock the PHY doesn't like to be
179 			 * powered on while at low speeds like those used in ID
180 			 * mode.  Even worse is powering the PHY on while the
181 			 * clock is off.
182 			 *
183 			 * To workaround the PHY limitations, the best we can
184 			 * do is to power it on at a faster speed and then slam
185 			 * through low speeds without power cycling.
186 			 */
187 			sdhci_set_clock(host, host->max_clk);
188 			phy_power_on(sdhci_arasan->phy);
189 			sdhci_arasan->is_phy_on = true;
190 
191 			/*
192 			 * We'll now fall through to the below case with
193 			 * ctrl_phy = false (so we won't turn off/on).  The
194 			 * sdhci_set_clock() will set the real clock.
195 			 */
196 		} else if (clock > PHY_CLK_TOO_SLOW_HZ) {
197 			/*
198 			 * At higher clock speeds the PHY is fine being power
199 			 * cycled and docs say you _should_ power cycle when
200 			 * changing clock speeds.
201 			 */
202 			ctrl_phy = true;
203 		}
204 	}
205 
206 	if (ctrl_phy && sdhci_arasan->is_phy_on) {
207 		phy_power_off(sdhci_arasan->phy);
208 		sdhci_arasan->is_phy_on = false;
209 	}
210 
211 	sdhci_set_clock(host, clock);
212 
213 	if (sdhci_arasan->quirks & SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE)
214 		/*
215 		 * Some controllers immediately report SDHCI_CLOCK_INT_STABLE
216 		 * after enabling the clock even though the clock is not
217 		 * stable. Trying to use a clock without waiting here results
218 		 * in EILSEQ while detecting some older/slower cards. The
219 		 * chosen delay is the maximum delay from sdhci_set_clock.
220 		 */
221 		msleep(20);
222 
223 	if (ctrl_phy) {
224 		phy_power_on(sdhci_arasan->phy);
225 		sdhci_arasan->is_phy_on = true;
226 	}
227 }
228 
229 static void sdhci_arasan_hs400_enhanced_strobe(struct mmc_host *mmc,
230 					struct mmc_ios *ios)
231 {
232 	u32 vendor;
233 	struct sdhci_host *host = mmc_priv(mmc);
234 
235 	vendor = sdhci_readl(host, SDHCI_ARASAN_VENDOR_REGISTER);
236 	if (ios->enhanced_strobe)
237 		vendor |= VENDOR_ENHANCED_STROBE;
238 	else
239 		vendor &= ~VENDOR_ENHANCED_STROBE;
240 
241 	sdhci_writel(host, vendor, SDHCI_ARASAN_VENDOR_REGISTER);
242 }
243 
244 static void sdhci_arasan_reset(struct sdhci_host *host, u8 mask)
245 {
246 	u8 ctrl;
247 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
248 	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
249 
250 	sdhci_reset(host, mask);
251 
252 	if (sdhci_arasan->quirks & SDHCI_ARASAN_QUIRK_FORCE_CDTEST) {
253 		ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
254 		ctrl |= SDHCI_CTRL_CDTEST_INS | SDHCI_CTRL_CDTEST_EN;
255 		sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
256 	}
257 }
258 
259 static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
260 				       struct mmc_ios *ios)
261 {
262 	switch (ios->signal_voltage) {
263 	case MMC_SIGNAL_VOLTAGE_180:
264 		/*
265 		 * Plese don't switch to 1V8 as arasan,5.1 doesn't
266 		 * actually refer to this setting to indicate the
267 		 * signal voltage and the state machine will be broken
268 		 * actually if we force to enable 1V8. That's something
269 		 * like broken quirk but we could work around here.
270 		 */
271 		return 0;
272 	case MMC_SIGNAL_VOLTAGE_330:
273 	case MMC_SIGNAL_VOLTAGE_120:
274 		/* We don't support 3V3 and 1V2 */
275 		break;
276 	}
277 
278 	return -EINVAL;
279 }
280 
281 static void sdhci_arasan_set_power(struct sdhci_host *host, unsigned char mode,
282 		     unsigned short vdd)
283 {
284 	if (!IS_ERR(host->mmc->supply.vmmc)) {
285 		struct mmc_host *mmc = host->mmc;
286 
287 		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
288 	}
289 	sdhci_set_power_noreg(host, mode, vdd);
290 }
291 
292 static const struct sdhci_ops sdhci_arasan_ops = {
293 	.set_clock = sdhci_arasan_set_clock,
294 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
295 	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
296 	.set_bus_width = sdhci_set_bus_width,
297 	.reset = sdhci_arasan_reset,
298 	.set_uhs_signaling = sdhci_set_uhs_signaling,
299 	.set_power = sdhci_arasan_set_power,
300 };
301 
302 static const struct sdhci_pltfm_data sdhci_arasan_pdata = {
303 	.ops = &sdhci_arasan_ops,
304 	.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
305 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
306 			SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN |
307 			SDHCI_QUIRK2_STOP_WITH_TC,
308 };
309 
310 static u32 sdhci_arasan_cqhci_irq(struct sdhci_host *host, u32 intmask)
311 {
312 	int cmd_error = 0;
313 	int data_error = 0;
314 
315 	if (!sdhci_cqe_irq(host, intmask, &cmd_error, &data_error))
316 		return intmask;
317 
318 	cqhci_irq(host->mmc, intmask, cmd_error, data_error);
319 
320 	return 0;
321 }
322 
323 static void sdhci_arasan_dumpregs(struct mmc_host *mmc)
324 {
325 	sdhci_dumpregs(mmc_priv(mmc));
326 }
327 
328 static void sdhci_arasan_cqe_enable(struct mmc_host *mmc)
329 {
330 	struct sdhci_host *host = mmc_priv(mmc);
331 	u32 reg;
332 
333 	reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
334 	while (reg & SDHCI_DATA_AVAILABLE) {
335 		sdhci_readl(host, SDHCI_BUFFER);
336 		reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
337 	}
338 
339 	sdhci_cqe_enable(mmc);
340 }
341 
342 static const struct cqhci_host_ops sdhci_arasan_cqhci_ops = {
343 	.enable         = sdhci_arasan_cqe_enable,
344 	.disable        = sdhci_cqe_disable,
345 	.dumpregs       = sdhci_arasan_dumpregs,
346 };
347 
348 static const struct sdhci_ops sdhci_arasan_cqe_ops = {
349 	.set_clock = sdhci_arasan_set_clock,
350 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
351 	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
352 	.set_bus_width = sdhci_set_bus_width,
353 	.reset = sdhci_arasan_reset,
354 	.set_uhs_signaling = sdhci_set_uhs_signaling,
355 	.set_power = sdhci_arasan_set_power,
356 	.irq = sdhci_arasan_cqhci_irq,
357 };
358 
359 static const struct sdhci_pltfm_data sdhci_arasan_cqe_pdata = {
360 	.ops = &sdhci_arasan_cqe_ops,
361 	.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
362 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
363 			SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN,
364 };
365 
366 #ifdef CONFIG_PM_SLEEP
367 /**
368  * sdhci_arasan_suspend - Suspend method for the driver
369  * @dev:	Address of the device structure
370  * Returns 0 on success and error value on error
371  *
372  * Put the device in a low power state.
373  */
374 static int sdhci_arasan_suspend(struct device *dev)
375 {
376 	struct sdhci_host *host = dev_get_drvdata(dev);
377 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
378 	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
379 	int ret;
380 
381 	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
382 		mmc_retune_needed(host->mmc);
383 
384 	if (sdhci_arasan->has_cqe) {
385 		ret = cqhci_suspend(host->mmc);
386 		if (ret)
387 			return ret;
388 	}
389 
390 	ret = sdhci_suspend_host(host);
391 	if (ret)
392 		return ret;
393 
394 	if (!IS_ERR(sdhci_arasan->phy) && sdhci_arasan->is_phy_on) {
395 		ret = phy_power_off(sdhci_arasan->phy);
396 		if (ret) {
397 			dev_err(dev, "Cannot power off phy.\n");
398 			sdhci_resume_host(host);
399 			return ret;
400 		}
401 		sdhci_arasan->is_phy_on = false;
402 	}
403 
404 	clk_disable(pltfm_host->clk);
405 	clk_disable(sdhci_arasan->clk_ahb);
406 
407 	return 0;
408 }
409 
410 /**
411  * sdhci_arasan_resume - Resume method for the driver
412  * @dev:	Address of the device structure
413  * Returns 0 on success and error value on error
414  *
415  * Resume operation after suspend
416  */
417 static int sdhci_arasan_resume(struct device *dev)
418 {
419 	struct sdhci_host *host = dev_get_drvdata(dev);
420 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
421 	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
422 	int ret;
423 
424 	ret = clk_enable(sdhci_arasan->clk_ahb);
425 	if (ret) {
426 		dev_err(dev, "Cannot enable AHB clock.\n");
427 		return ret;
428 	}
429 
430 	ret = clk_enable(pltfm_host->clk);
431 	if (ret) {
432 		dev_err(dev, "Cannot enable SD clock.\n");
433 		return ret;
434 	}
435 
436 	if (!IS_ERR(sdhci_arasan->phy) && host->mmc->actual_clock) {
437 		ret = phy_power_on(sdhci_arasan->phy);
438 		if (ret) {
439 			dev_err(dev, "Cannot power on phy.\n");
440 			return ret;
441 		}
442 		sdhci_arasan->is_phy_on = true;
443 	}
444 
445 	ret = sdhci_resume_host(host);
446 	if (ret) {
447 		dev_err(dev, "Cannot resume host.\n");
448 		return ret;
449 	}
450 
451 	if (sdhci_arasan->has_cqe)
452 		return cqhci_resume(host->mmc);
453 
454 	return 0;
455 }
456 #endif /* ! CONFIG_PM_SLEEP */
457 
458 static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
459 			 sdhci_arasan_resume);
460 
461 static const struct of_device_id sdhci_arasan_of_match[] = {
462 	/* SoC-specific compatible strings w/ soc_ctl_map */
463 	{
464 		.compatible = "rockchip,rk3399-sdhci-5.1",
465 		.data = &rk3399_soc_ctl_map,
466 	},
467 
468 	/* Generic compatible below here */
469 	{ .compatible = "arasan,sdhci-8.9a" },
470 	{ .compatible = "arasan,sdhci-5.1" },
471 	{ .compatible = "arasan,sdhci-4.9a" },
472 
473 	{ /* sentinel */ }
474 };
475 MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
476 
477 /**
478  * sdhci_arasan_sdcardclk_recalc_rate - Return the card clock rate
479  *
480  * Return the current actual rate of the SD card clock.  This can be used
481  * to communicate with out PHY.
482  *
483  * @hw:			Pointer to the hardware clock structure.
484  * @parent_rate		The parent rate (should be rate of clk_xin).
485  * Returns the card clock rate.
486  */
487 static unsigned long sdhci_arasan_sdcardclk_recalc_rate(struct clk_hw *hw,
488 						      unsigned long parent_rate)
489 
490 {
491 	struct sdhci_arasan_data *sdhci_arasan =
492 		container_of(hw, struct sdhci_arasan_data, sdcardclk_hw);
493 	struct sdhci_host *host = sdhci_arasan->host;
494 
495 	return host->mmc->actual_clock;
496 }
497 
498 static const struct clk_ops arasan_sdcardclk_ops = {
499 	.recalc_rate = sdhci_arasan_sdcardclk_recalc_rate,
500 };
501 
502 /**
503  * sdhci_arasan_update_clockmultiplier - Set corecfg_clockmultiplier
504  *
505  * The corecfg_clockmultiplier is supposed to contain clock multiplier
506  * value of programmable clock generator.
507  *
508  * NOTES:
509  * - Many existing devices don't seem to do this and work fine.  To keep
510  *   compatibility for old hardware where the device tree doesn't provide a
511  *   register map, this function is a noop if a soc_ctl_map hasn't been provided
512  *   for this platform.
513  * - The value of corecfg_clockmultiplier should sync with that of corresponding
514  *   value reading from sdhci_capability_register. So this function is called
515  *   once at probe time and never called again.
516  *
517  * @host:		The sdhci_host
518  */
519 static void sdhci_arasan_update_clockmultiplier(struct sdhci_host *host,
520 						u32 value)
521 {
522 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
523 	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
524 	const struct sdhci_arasan_soc_ctl_map *soc_ctl_map =
525 		sdhci_arasan->soc_ctl_map;
526 
527 	/* Having a map is optional */
528 	if (!soc_ctl_map)
529 		return;
530 
531 	/* If we have a map, we expect to have a syscon */
532 	if (!sdhci_arasan->soc_ctl_base) {
533 		pr_warn("%s: Have regmap, but no soc-ctl-syscon\n",
534 			mmc_hostname(host->mmc));
535 		return;
536 	}
537 
538 	sdhci_arasan_syscon_write(host, &soc_ctl_map->clockmultiplier, value);
539 }
540 
541 /**
542  * sdhci_arasan_update_baseclkfreq - Set corecfg_baseclkfreq
543  *
544  * The corecfg_baseclkfreq is supposed to contain the MHz of clk_xin.  This
545  * function can be used to make that happen.
546  *
547  * NOTES:
548  * - Many existing devices don't seem to do this and work fine.  To keep
549  *   compatibility for old hardware where the device tree doesn't provide a
550  *   register map, this function is a noop if a soc_ctl_map hasn't been provided
551  *   for this platform.
552  * - It's assumed that clk_xin is not dynamic and that we use the SDHCI divider
553  *   to achieve lower clock rates.  That means that this function is called once
554  *   at probe time and never called again.
555  *
556  * @host:		The sdhci_host
557  */
558 static void sdhci_arasan_update_baseclkfreq(struct sdhci_host *host)
559 {
560 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
561 	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
562 	const struct sdhci_arasan_soc_ctl_map *soc_ctl_map =
563 		sdhci_arasan->soc_ctl_map;
564 	u32 mhz = DIV_ROUND_CLOSEST(clk_get_rate(pltfm_host->clk), 1000000);
565 
566 	/* Having a map is optional */
567 	if (!soc_ctl_map)
568 		return;
569 
570 	/* If we have a map, we expect to have a syscon */
571 	if (!sdhci_arasan->soc_ctl_base) {
572 		pr_warn("%s: Have regmap, but no soc-ctl-syscon\n",
573 			mmc_hostname(host->mmc));
574 		return;
575 	}
576 
577 	sdhci_arasan_syscon_write(host, &soc_ctl_map->baseclkfreq, mhz);
578 }
579 
580 /**
581  * sdhci_arasan_register_sdclk - Register the sdclk for a PHY to use
582  *
583  * Some PHY devices need to know what the actual card clock is.  In order for
584  * them to find out, we'll provide a clock through the common clock framework
585  * for them to query.
586  *
587  * Note: without seriously re-architecting SDHCI's clock code and testing on
588  * all platforms, there's no way to create a totally beautiful clock here
589  * with all clock ops implemented.  Instead, we'll just create a clock that can
590  * be queried and set the CLK_GET_RATE_NOCACHE attribute to tell common clock
591  * framework that we're doing things behind its back.  This should be sufficient
592  * to create nice clean device tree bindings and later (if needed) we can try
593  * re-architecting SDHCI if we see some benefit to it.
594  *
595  * @sdhci_arasan:	Our private data structure.
596  * @clk_xin:		Pointer to the functional clock
597  * @dev:		Pointer to our struct device.
598  * Returns 0 on success and error value on error
599  */
600 static int sdhci_arasan_register_sdclk(struct sdhci_arasan_data *sdhci_arasan,
601 				       struct clk *clk_xin,
602 				       struct device *dev)
603 {
604 	struct device_node *np = dev->of_node;
605 	struct clk_init_data sdcardclk_init;
606 	const char *parent_clk_name;
607 	int ret;
608 
609 	/* Providing a clock to the PHY is optional; no error if missing */
610 	if (!of_find_property(np, "#clock-cells", NULL))
611 		return 0;
612 
613 	ret = of_property_read_string_index(np, "clock-output-names", 0,
614 					    &sdcardclk_init.name);
615 	if (ret) {
616 		dev_err(dev, "DT has #clock-cells but no clock-output-names\n");
617 		return ret;
618 	}
619 
620 	parent_clk_name = __clk_get_name(clk_xin);
621 	sdcardclk_init.parent_names = &parent_clk_name;
622 	sdcardclk_init.num_parents = 1;
623 	sdcardclk_init.flags = CLK_GET_RATE_NOCACHE;
624 	sdcardclk_init.ops = &arasan_sdcardclk_ops;
625 
626 	sdhci_arasan->sdcardclk_hw.init = &sdcardclk_init;
627 	sdhci_arasan->sdcardclk =
628 		devm_clk_register(dev, &sdhci_arasan->sdcardclk_hw);
629 	sdhci_arasan->sdcardclk_hw.init = NULL;
630 
631 	ret = of_clk_add_provider(np, of_clk_src_simple_get,
632 				  sdhci_arasan->sdcardclk);
633 	if (ret)
634 		dev_err(dev, "Failed to add clock provider\n");
635 
636 	return ret;
637 }
638 
639 /**
640  * sdhci_arasan_unregister_sdclk - Undoes sdhci_arasan_register_sdclk()
641  *
642  * Should be called any time we're exiting and sdhci_arasan_register_sdclk()
643  * returned success.
644  *
645  * @dev:		Pointer to our struct device.
646  */
647 static void sdhci_arasan_unregister_sdclk(struct device *dev)
648 {
649 	struct device_node *np = dev->of_node;
650 
651 	if (!of_find_property(np, "#clock-cells", NULL))
652 		return;
653 
654 	of_clk_del_provider(dev->of_node);
655 }
656 
657 static int sdhci_arasan_add_host(struct sdhci_arasan_data *sdhci_arasan)
658 {
659 	struct sdhci_host *host = sdhci_arasan->host;
660 	struct cqhci_host *cq_host;
661 	bool dma64;
662 	int ret;
663 
664 	if (!sdhci_arasan->has_cqe)
665 		return sdhci_add_host(host);
666 
667 	ret = sdhci_setup_host(host);
668 	if (ret)
669 		return ret;
670 
671 	cq_host = devm_kzalloc(host->mmc->parent,
672 			       sizeof(*cq_host), GFP_KERNEL);
673 	if (!cq_host) {
674 		ret = -ENOMEM;
675 		goto cleanup;
676 	}
677 
678 	cq_host->mmio = host->ioaddr + SDHCI_ARASAN_CQE_BASE_ADDR;
679 	cq_host->ops = &sdhci_arasan_cqhci_ops;
680 
681 	dma64 = host->flags & SDHCI_USE_64_BIT_DMA;
682 	if (dma64)
683 		cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
684 
685 	ret = cqhci_init(cq_host, host->mmc, dma64);
686 	if (ret)
687 		goto cleanup;
688 
689 	ret = __sdhci_add_host(host);
690 	if (ret)
691 		goto cleanup;
692 
693 	return 0;
694 
695 cleanup:
696 	sdhci_cleanup_host(host);
697 	return ret;
698 }
699 
700 static int sdhci_arasan_probe(struct platform_device *pdev)
701 {
702 	int ret;
703 	const struct of_device_id *match;
704 	struct device_node *node;
705 	struct clk *clk_xin;
706 	struct sdhci_host *host;
707 	struct sdhci_pltfm_host *pltfm_host;
708 	struct sdhci_arasan_data *sdhci_arasan;
709 	struct device_node *np = pdev->dev.of_node;
710 	const struct sdhci_pltfm_data *pdata;
711 
712 	if (of_device_is_compatible(pdev->dev.of_node, "arasan,sdhci-5.1"))
713 		pdata = &sdhci_arasan_cqe_pdata;
714 	else
715 		pdata = &sdhci_arasan_pdata;
716 
717 	host = sdhci_pltfm_init(pdev, pdata, sizeof(*sdhci_arasan));
718 
719 	if (IS_ERR(host))
720 		return PTR_ERR(host);
721 
722 	pltfm_host = sdhci_priv(host);
723 	sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
724 	sdhci_arasan->host = host;
725 
726 	match = of_match_node(sdhci_arasan_of_match, pdev->dev.of_node);
727 	sdhci_arasan->soc_ctl_map = match->data;
728 
729 	node = of_parse_phandle(pdev->dev.of_node, "arasan,soc-ctl-syscon", 0);
730 	if (node) {
731 		sdhci_arasan->soc_ctl_base = syscon_node_to_regmap(node);
732 		of_node_put(node);
733 
734 		if (IS_ERR(sdhci_arasan->soc_ctl_base)) {
735 			ret = PTR_ERR(sdhci_arasan->soc_ctl_base);
736 			if (ret != -EPROBE_DEFER)
737 				dev_err(&pdev->dev, "Can't get syscon: %d\n",
738 					ret);
739 			goto err_pltfm_free;
740 		}
741 	}
742 
743 	sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb");
744 	if (IS_ERR(sdhci_arasan->clk_ahb)) {
745 		dev_err(&pdev->dev, "clk_ahb clock not found.\n");
746 		ret = PTR_ERR(sdhci_arasan->clk_ahb);
747 		goto err_pltfm_free;
748 	}
749 
750 	clk_xin = devm_clk_get(&pdev->dev, "clk_xin");
751 	if (IS_ERR(clk_xin)) {
752 		dev_err(&pdev->dev, "clk_xin clock not found.\n");
753 		ret = PTR_ERR(clk_xin);
754 		goto err_pltfm_free;
755 	}
756 
757 	ret = clk_prepare_enable(sdhci_arasan->clk_ahb);
758 	if (ret) {
759 		dev_err(&pdev->dev, "Unable to enable AHB clock.\n");
760 		goto err_pltfm_free;
761 	}
762 
763 	ret = clk_prepare_enable(clk_xin);
764 	if (ret) {
765 		dev_err(&pdev->dev, "Unable to enable SD clock.\n");
766 		goto clk_dis_ahb;
767 	}
768 
769 	sdhci_get_of_property(pdev);
770 
771 	if (of_property_read_bool(np, "xlnx,fails-without-test-cd"))
772 		sdhci_arasan->quirks |= SDHCI_ARASAN_QUIRK_FORCE_CDTEST;
773 
774 	if (of_property_read_bool(np, "xlnx,int-clock-stable-broken"))
775 		sdhci_arasan->quirks |= SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE;
776 
777 	pltfm_host->clk = clk_xin;
778 
779 	if (of_device_is_compatible(pdev->dev.of_node,
780 				    "rockchip,rk3399-sdhci-5.1"))
781 		sdhci_arasan_update_clockmultiplier(host, 0x0);
782 
783 	sdhci_arasan_update_baseclkfreq(host);
784 
785 	ret = sdhci_arasan_register_sdclk(sdhci_arasan, clk_xin, &pdev->dev);
786 	if (ret)
787 		goto clk_disable_all;
788 
789 	ret = mmc_of_parse(host->mmc);
790 	if (ret) {
791 		dev_err(&pdev->dev, "parsing dt failed (%d)\n", ret);
792 		goto unreg_clk;
793 	}
794 
795 	sdhci_arasan->phy = ERR_PTR(-ENODEV);
796 	if (of_device_is_compatible(pdev->dev.of_node,
797 				    "arasan,sdhci-5.1")) {
798 		sdhci_arasan->phy = devm_phy_get(&pdev->dev,
799 						 "phy_arasan");
800 		if (IS_ERR(sdhci_arasan->phy)) {
801 			ret = PTR_ERR(sdhci_arasan->phy);
802 			dev_err(&pdev->dev, "No phy for arasan,sdhci-5.1.\n");
803 			goto unreg_clk;
804 		}
805 
806 		ret = phy_init(sdhci_arasan->phy);
807 		if (ret < 0) {
808 			dev_err(&pdev->dev, "phy_init err.\n");
809 			goto unreg_clk;
810 		}
811 
812 		host->mmc_host_ops.hs400_enhanced_strobe =
813 					sdhci_arasan_hs400_enhanced_strobe;
814 		host->mmc_host_ops.start_signal_voltage_switch =
815 					sdhci_arasan_voltage_switch;
816 		sdhci_arasan->has_cqe = true;
817 		host->mmc->caps2 |= MMC_CAP2_CQE | MMC_CAP2_CQE_DCMD;
818 	}
819 
820 	ret = sdhci_arasan_add_host(sdhci_arasan);
821 	if (ret)
822 		goto err_add_host;
823 
824 	return 0;
825 
826 err_add_host:
827 	if (!IS_ERR(sdhci_arasan->phy))
828 		phy_exit(sdhci_arasan->phy);
829 unreg_clk:
830 	sdhci_arasan_unregister_sdclk(&pdev->dev);
831 clk_disable_all:
832 	clk_disable_unprepare(clk_xin);
833 clk_dis_ahb:
834 	clk_disable_unprepare(sdhci_arasan->clk_ahb);
835 err_pltfm_free:
836 	sdhci_pltfm_free(pdev);
837 	return ret;
838 }
839 
840 static int sdhci_arasan_remove(struct platform_device *pdev)
841 {
842 	int ret;
843 	struct sdhci_host *host = platform_get_drvdata(pdev);
844 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
845 	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
846 	struct clk *clk_ahb = sdhci_arasan->clk_ahb;
847 
848 	if (!IS_ERR(sdhci_arasan->phy)) {
849 		if (sdhci_arasan->is_phy_on)
850 			phy_power_off(sdhci_arasan->phy);
851 		phy_exit(sdhci_arasan->phy);
852 	}
853 
854 	sdhci_arasan_unregister_sdclk(&pdev->dev);
855 
856 	ret = sdhci_pltfm_unregister(pdev);
857 
858 	clk_disable_unprepare(clk_ahb);
859 
860 	return ret;
861 }
862 
863 static struct platform_driver sdhci_arasan_driver = {
864 	.driver = {
865 		.name = "sdhci-arasan",
866 		.of_match_table = sdhci_arasan_of_match,
867 		.pm = &sdhci_arasan_dev_pm_ops,
868 	},
869 	.probe = sdhci_arasan_probe,
870 	.remove = sdhci_arasan_remove,
871 };
872 
873 module_platform_driver(sdhci_arasan_driver);
874 
875 MODULE_DESCRIPTION("Driver for the Arasan SDHCI Controller");
876 MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com>");
877 MODULE_LICENSE("GPL");
878