xref: /openbmc/linux/drivers/mmc/host/sdhci-xenon.c (revision dea54fba)
1 /*
2  * Driver for Marvell Xenon SDHC as a platform device
3  *
4  * Copyright (C) 2016 Marvell, All Rights Reserved.
5  *
6  * Author:	Hu Ziji <huziji@marvell.com>
7  * Date:	2016-8-24
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation version 2.
12  *
13  * Inspired by Jisheng Zhang <jszhang@marvell.com>
14  * Special thanks to Video BG4 project team.
15  */
16 
17 #include <linux/delay.h>
18 #include <linux/ktime.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 
22 #include "sdhci-pltfm.h"
23 #include "sdhci-xenon.h"
24 
25 static int xenon_enable_internal_clk(struct sdhci_host *host)
26 {
27 	u32 reg;
28 	ktime_t timeout;
29 
30 	reg = sdhci_readl(host, SDHCI_CLOCK_CONTROL);
31 	reg |= SDHCI_CLOCK_INT_EN;
32 	sdhci_writel(host, reg, SDHCI_CLOCK_CONTROL);
33 	/* Wait max 20 ms */
34 	timeout = ktime_add_ms(ktime_get(), 20);
35 	while (!((reg = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
36 			& SDHCI_CLOCK_INT_STABLE)) {
37 		if (ktime_after(ktime_get(), timeout)) {
38 			dev_err(mmc_dev(host->mmc), "Internal clock never stabilised.\n");
39 			return -ETIMEDOUT;
40 		}
41 		usleep_range(900, 1100);
42 	}
43 
44 	return 0;
45 }
46 
47 /* Set SDCLK-off-while-idle */
48 static void xenon_set_sdclk_off_idle(struct sdhci_host *host,
49 				     unsigned char sdhc_id, bool enable)
50 {
51 	u32 reg;
52 	u32 mask;
53 
54 	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
55 	/* Get the bit shift basing on the SDHC index */
56 	mask = (0x1 << (XENON_SDCLK_IDLEOFF_ENABLE_SHIFT + sdhc_id));
57 	if (enable)
58 		reg |= mask;
59 	else
60 		reg &= ~mask;
61 
62 	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
63 }
64 
65 /* Enable/Disable the Auto Clock Gating function */
66 static void xenon_set_acg(struct sdhci_host *host, bool enable)
67 {
68 	u32 reg;
69 
70 	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
71 	if (enable)
72 		reg &= ~XENON_AUTO_CLKGATE_DISABLE_MASK;
73 	else
74 		reg |= XENON_AUTO_CLKGATE_DISABLE_MASK;
75 	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
76 }
77 
78 /* Enable this SDHC */
79 static void xenon_enable_sdhc(struct sdhci_host *host,
80 			      unsigned char sdhc_id)
81 {
82 	u32 reg;
83 
84 	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
85 	reg |= (BIT(sdhc_id) << XENON_SLOT_ENABLE_SHIFT);
86 	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
87 
88 	host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
89 	/*
90 	 * Force to clear BUS_TEST to
91 	 * skip bus_test_pre and bus_test_post
92 	 */
93 	host->mmc->caps &= ~MMC_CAP_BUS_WIDTH_TEST;
94 }
95 
96 /* Disable this SDHC */
97 static void xenon_disable_sdhc(struct sdhci_host *host,
98 			       unsigned char sdhc_id)
99 {
100 	u32 reg;
101 
102 	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
103 	reg &= ~(BIT(sdhc_id) << XENON_SLOT_ENABLE_SHIFT);
104 	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
105 }
106 
107 /* Enable Parallel Transfer Mode */
108 static void xenon_enable_sdhc_parallel_tran(struct sdhci_host *host,
109 					    unsigned char sdhc_id)
110 {
111 	u32 reg;
112 
113 	reg = sdhci_readl(host, XENON_SYS_EXT_OP_CTRL);
114 	reg |= BIT(sdhc_id);
115 	sdhci_writel(host, reg, XENON_SYS_EXT_OP_CTRL);
116 }
117 
118 /* Mask command conflict error */
119 static void xenon_mask_cmd_conflict_err(struct sdhci_host *host)
120 {
121 	u32  reg;
122 
123 	reg = sdhci_readl(host, XENON_SYS_EXT_OP_CTRL);
124 	reg |= XENON_MASK_CMD_CONFLICT_ERR;
125 	sdhci_writel(host, reg, XENON_SYS_EXT_OP_CTRL);
126 }
127 
128 static void xenon_retune_setup(struct sdhci_host *host)
129 {
130 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
131 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
132 	u32 reg;
133 
134 	/* Disable the Re-Tuning Request functionality */
135 	reg = sdhci_readl(host, XENON_SLOT_RETUNING_REQ_CTRL);
136 	reg &= ~XENON_RETUNING_COMPATIBLE;
137 	sdhci_writel(host, reg, XENON_SLOT_RETUNING_REQ_CTRL);
138 
139 	/* Disable the Re-tuning Interrupt */
140 	reg = sdhci_readl(host, SDHCI_SIGNAL_ENABLE);
141 	reg &= ~SDHCI_INT_RETUNE;
142 	sdhci_writel(host, reg, SDHCI_SIGNAL_ENABLE);
143 	reg = sdhci_readl(host, SDHCI_INT_ENABLE);
144 	reg &= ~SDHCI_INT_RETUNE;
145 	sdhci_writel(host, reg, SDHCI_INT_ENABLE);
146 
147 	/* Force to use Tuning Mode 1 */
148 	host->tuning_mode = SDHCI_TUNING_MODE_1;
149 	/* Set re-tuning period */
150 	host->tuning_count = 1 << (priv->tuning_count - 1);
151 }
152 
153 /*
154  * Operations inside struct sdhci_ops
155  */
156 /* Recover the Register Setting cleared during SOFTWARE_RESET_ALL */
157 static void xenon_reset_exit(struct sdhci_host *host,
158 			     unsigned char sdhc_id, u8 mask)
159 {
160 	/* Only SOFTWARE RESET ALL will clear the register setting */
161 	if (!(mask & SDHCI_RESET_ALL))
162 		return;
163 
164 	/* Disable tuning request and auto-retuning again */
165 	xenon_retune_setup(host);
166 
167 	xenon_set_acg(host, true);
168 
169 	xenon_set_sdclk_off_idle(host, sdhc_id, false);
170 
171 	xenon_mask_cmd_conflict_err(host);
172 }
173 
174 static void xenon_reset(struct sdhci_host *host, u8 mask)
175 {
176 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
177 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
178 
179 	sdhci_reset(host, mask);
180 	xenon_reset_exit(host, priv->sdhc_id, mask);
181 }
182 
183 /*
184  * Xenon defines different values for HS200 and HS400
185  * in Host_Control_2
186  */
187 static void xenon_set_uhs_signaling(struct sdhci_host *host,
188 				    unsigned int timing)
189 {
190 	u16 ctrl_2;
191 
192 	ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
193 	/* Select Bus Speed Mode for host */
194 	ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
195 	if (timing == MMC_TIMING_MMC_HS200)
196 		ctrl_2 |= XENON_CTRL_HS200;
197 	else if (timing == MMC_TIMING_UHS_SDR104)
198 		ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
199 	else if (timing == MMC_TIMING_UHS_SDR12)
200 		ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
201 	else if (timing == MMC_TIMING_UHS_SDR25)
202 		ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
203 	else if (timing == MMC_TIMING_UHS_SDR50)
204 		ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
205 	else if ((timing == MMC_TIMING_UHS_DDR50) ||
206 		 (timing == MMC_TIMING_MMC_DDR52))
207 		ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
208 	else if (timing == MMC_TIMING_MMC_HS400)
209 		ctrl_2 |= XENON_CTRL_HS400;
210 	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
211 }
212 
213 static const struct sdhci_ops sdhci_xenon_ops = {
214 	.set_clock		= sdhci_set_clock,
215 	.set_bus_width		= sdhci_set_bus_width,
216 	.reset			= xenon_reset,
217 	.set_uhs_signaling	= xenon_set_uhs_signaling,
218 	.get_max_clock		= sdhci_pltfm_clk_get_max_clock,
219 };
220 
221 static const struct sdhci_pltfm_data sdhci_xenon_pdata = {
222 	.ops = &sdhci_xenon_ops,
223 	.quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC |
224 		  SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER |
225 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
226 };
227 
228 /*
229  * Xenon Specific Operations in mmc_host_ops
230  */
231 static void xenon_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
232 {
233 	struct sdhci_host *host = mmc_priv(mmc);
234 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
235 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
236 	u32 reg;
237 
238 	/*
239 	 * HS400/HS200/eMMC HS doesn't have Preset Value register.
240 	 * However, sdhci_set_ios will read HS400/HS200 Preset register.
241 	 * Disable Preset Value register for HS400/HS200.
242 	 * eMMC HS with preset_enabled set will trigger a bug in
243 	 * get_preset_value().
244 	 */
245 	if ((ios->timing == MMC_TIMING_MMC_HS400) ||
246 	    (ios->timing == MMC_TIMING_MMC_HS200) ||
247 	    (ios->timing == MMC_TIMING_MMC_HS)) {
248 		host->preset_enabled = false;
249 		host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
250 		host->flags &= ~SDHCI_PV_ENABLED;
251 
252 		reg = sdhci_readw(host, SDHCI_HOST_CONTROL2);
253 		reg &= ~SDHCI_CTRL_PRESET_VAL_ENABLE;
254 		sdhci_writew(host, reg, SDHCI_HOST_CONTROL2);
255 	} else {
256 		host->quirks2 &= ~SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
257 	}
258 
259 	sdhci_set_ios(mmc, ios);
260 	xenon_phy_adj(host, ios);
261 
262 	if (host->clock > XENON_DEFAULT_SDCLK_FREQ)
263 		xenon_set_sdclk_off_idle(host, priv->sdhc_id, true);
264 }
265 
266 static int xenon_start_signal_voltage_switch(struct mmc_host *mmc,
267 					     struct mmc_ios *ios)
268 {
269 	struct sdhci_host *host = mmc_priv(mmc);
270 
271 	/*
272 	 * Before SD/SDIO set signal voltage, SD bus clock should be
273 	 * disabled. However, sdhci_set_clock will also disable the Internal
274 	 * clock in mmc_set_signal_voltage().
275 	 * If Internal clock is disabled, the 3.3V/1.8V bit can not be updated.
276 	 * Thus here manually enable internal clock.
277 	 *
278 	 * After switch completes, it is unnecessary to disable internal clock,
279 	 * since keeping internal clock active obeys SD spec.
280 	 */
281 	xenon_enable_internal_clk(host);
282 
283 	xenon_soc_pad_ctrl(host, ios->signal_voltage);
284 
285 	/*
286 	 * If Vqmmc is fixed on platform, vqmmc regulator should be unavailable.
287 	 * Thus SDHCI_CTRL_VDD_180 bit might not work then.
288 	 * Skip the standard voltage switch to avoid any issue.
289 	 */
290 	if (PTR_ERR(mmc->supply.vqmmc) == -ENODEV)
291 		return 0;
292 
293 	return sdhci_start_signal_voltage_switch(mmc, ios);
294 }
295 
296 /*
297  * Update card type.
298  * priv->init_card_type will be used in PHY timing adjustment.
299  */
300 static void xenon_init_card(struct mmc_host *mmc, struct mmc_card *card)
301 {
302 	struct sdhci_host *host = mmc_priv(mmc);
303 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
304 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
305 
306 	/* Update card type*/
307 	priv->init_card_type = card->type;
308 }
309 
310 static int xenon_execute_tuning(struct mmc_host *mmc, u32 opcode)
311 {
312 	struct sdhci_host *host = mmc_priv(mmc);
313 
314 	if (host->timing == MMC_TIMING_UHS_DDR50)
315 		return 0;
316 
317 	/*
318 	 * Currently force Xenon driver back to support mode 1 only,
319 	 * even though Xenon might claim to support mode 2 or mode 3.
320 	 * It requires more time to test mode 2/mode 3 on more platforms.
321 	 */
322 	if (host->tuning_mode != SDHCI_TUNING_MODE_1)
323 		xenon_retune_setup(host);
324 
325 	return sdhci_execute_tuning(mmc, opcode);
326 }
327 
328 static void xenon_enable_sdio_irq(struct mmc_host *mmc, int enable)
329 {
330 	struct sdhci_host *host = mmc_priv(mmc);
331 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
332 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
333 	u32 reg;
334 	u8 sdhc_id = priv->sdhc_id;
335 
336 	sdhci_enable_sdio_irq(mmc, enable);
337 
338 	if (enable) {
339 		/*
340 		 * Set SDIO Card Inserted indication
341 		 * to enable detecting SDIO async irq.
342 		 */
343 		reg = sdhci_readl(host, XENON_SYS_CFG_INFO);
344 		reg |= (1 << (sdhc_id + XENON_SLOT_TYPE_SDIO_SHIFT));
345 		sdhci_writel(host, reg, XENON_SYS_CFG_INFO);
346 	} else {
347 		/* Clear SDIO Card Inserted indication */
348 		reg = sdhci_readl(host, XENON_SYS_CFG_INFO);
349 		reg &= ~(1 << (sdhc_id + XENON_SLOT_TYPE_SDIO_SHIFT));
350 		sdhci_writel(host, reg, XENON_SYS_CFG_INFO);
351 	}
352 }
353 
354 static void xenon_replace_mmc_host_ops(struct sdhci_host *host)
355 {
356 	host->mmc_host_ops.set_ios = xenon_set_ios;
357 	host->mmc_host_ops.start_signal_voltage_switch =
358 			xenon_start_signal_voltage_switch;
359 	host->mmc_host_ops.init_card = xenon_init_card;
360 	host->mmc_host_ops.execute_tuning = xenon_execute_tuning;
361 	host->mmc_host_ops.enable_sdio_irq = xenon_enable_sdio_irq;
362 }
363 
364 /*
365  * Parse Xenon specific DT properties:
366  * sdhc-id: the index of current SDHC.
367  *	    Refer to XENON_SYS_CFG_INFO register
368  * tun-count: the interval between re-tuning
369  */
370 static int xenon_probe_dt(struct platform_device *pdev)
371 {
372 	struct device_node *np = pdev->dev.of_node;
373 	struct sdhci_host *host = platform_get_drvdata(pdev);
374 	struct mmc_host *mmc = host->mmc;
375 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
376 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
377 	u32 sdhc_id, nr_sdhc;
378 	u32 tuning_count;
379 
380 	/* Disable HS200 on Armada AP806 */
381 	if (of_device_is_compatible(np, "marvell,armada-ap806-sdhci"))
382 		host->quirks2 |= SDHCI_QUIRK2_BROKEN_HS200;
383 
384 	sdhc_id = 0x0;
385 	if (!of_property_read_u32(np, "marvell,xenon-sdhc-id", &sdhc_id)) {
386 		nr_sdhc = sdhci_readl(host, XENON_SYS_CFG_INFO);
387 		nr_sdhc &= XENON_NR_SUPPORTED_SLOT_MASK;
388 		if (unlikely(sdhc_id > nr_sdhc)) {
389 			dev_err(mmc_dev(mmc), "SDHC Index %d exceeds Number of SDHCs %d\n",
390 				sdhc_id, nr_sdhc);
391 			return -EINVAL;
392 		}
393 	}
394 	priv->sdhc_id = sdhc_id;
395 
396 	tuning_count = XENON_DEF_TUNING_COUNT;
397 	if (!of_property_read_u32(np, "marvell,xenon-tun-count",
398 				  &tuning_count)) {
399 		if (unlikely(tuning_count >= XENON_TMR_RETUN_NO_PRESENT)) {
400 			dev_err(mmc_dev(mmc), "Wrong Re-tuning Count. Set default value %d\n",
401 				XENON_DEF_TUNING_COUNT);
402 			tuning_count = XENON_DEF_TUNING_COUNT;
403 		}
404 	}
405 	priv->tuning_count = tuning_count;
406 
407 	return xenon_phy_parse_dt(np, host);
408 }
409 
410 static int xenon_sdhc_prepare(struct sdhci_host *host)
411 {
412 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
413 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
414 	u8 sdhc_id = priv->sdhc_id;
415 
416 	/* Enable SDHC */
417 	xenon_enable_sdhc(host, sdhc_id);
418 
419 	/* Enable ACG */
420 	xenon_set_acg(host, true);
421 
422 	/* Enable Parallel Transfer Mode */
423 	xenon_enable_sdhc_parallel_tran(host, sdhc_id);
424 
425 	/* Disable SDCLK-Off-While-Idle before card init */
426 	xenon_set_sdclk_off_idle(host, sdhc_id, false);
427 
428 	xenon_mask_cmd_conflict_err(host);
429 
430 	return 0;
431 }
432 
433 static void xenon_sdhc_unprepare(struct sdhci_host *host)
434 {
435 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
436 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
437 	u8 sdhc_id = priv->sdhc_id;
438 
439 	/* disable SDHC */
440 	xenon_disable_sdhc(host, sdhc_id);
441 }
442 
443 static int xenon_probe(struct platform_device *pdev)
444 {
445 	struct sdhci_pltfm_host *pltfm_host;
446 	struct sdhci_host *host;
447 	struct xenon_priv *priv;
448 	int err;
449 
450 	host = sdhci_pltfm_init(pdev, &sdhci_xenon_pdata,
451 				sizeof(struct xenon_priv));
452 	if (IS_ERR(host))
453 		return PTR_ERR(host);
454 
455 	pltfm_host = sdhci_priv(host);
456 	priv = sdhci_pltfm_priv(pltfm_host);
457 
458 	/*
459 	 * Link Xenon specific mmc_host_ops function,
460 	 * to replace standard ones in sdhci_ops.
461 	 */
462 	xenon_replace_mmc_host_ops(host);
463 
464 	pltfm_host->clk = devm_clk_get(&pdev->dev, "core");
465 	if (IS_ERR(pltfm_host->clk)) {
466 		err = PTR_ERR(pltfm_host->clk);
467 		dev_err(&pdev->dev, "Failed to setup input clk: %d\n", err);
468 		goto free_pltfm;
469 	}
470 	err = clk_prepare_enable(pltfm_host->clk);
471 	if (err)
472 		goto free_pltfm;
473 
474 	err = mmc_of_parse(host->mmc);
475 	if (err)
476 		goto err_clk;
477 
478 	sdhci_get_of_property(pdev);
479 
480 	xenon_set_acg(host, false);
481 
482 	/* Xenon specific dt parse */
483 	err = xenon_probe_dt(pdev);
484 	if (err)
485 		goto err_clk;
486 
487 	err = xenon_sdhc_prepare(host);
488 	if (err)
489 		goto err_clk;
490 
491 	err = sdhci_add_host(host);
492 	if (err)
493 		goto remove_sdhc;
494 
495 	return 0;
496 
497 remove_sdhc:
498 	xenon_sdhc_unprepare(host);
499 err_clk:
500 	clk_disable_unprepare(pltfm_host->clk);
501 free_pltfm:
502 	sdhci_pltfm_free(pdev);
503 	return err;
504 }
505 
506 static int xenon_remove(struct platform_device *pdev)
507 {
508 	struct sdhci_host *host = platform_get_drvdata(pdev);
509 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
510 
511 	sdhci_remove_host(host, 0);
512 
513 	xenon_sdhc_unprepare(host);
514 
515 	clk_disable_unprepare(pltfm_host->clk);
516 
517 	sdhci_pltfm_free(pdev);
518 
519 	return 0;
520 }
521 
522 static const struct of_device_id sdhci_xenon_dt_ids[] = {
523 	{ .compatible = "marvell,armada-ap806-sdhci",},
524 	{ .compatible = "marvell,armada-cp110-sdhci",},
525 	{ .compatible = "marvell,armada-3700-sdhci",},
526 	{}
527 };
528 MODULE_DEVICE_TABLE(of, sdhci_xenon_dt_ids);
529 
530 static struct platform_driver sdhci_xenon_driver = {
531 	.driver	= {
532 		.name	= "xenon-sdhci",
533 		.of_match_table = sdhci_xenon_dt_ids,
534 		.pm = &sdhci_pltfm_pmops,
535 	},
536 	.probe	= xenon_probe,
537 	.remove	= xenon_remove,
538 };
539 
540 module_platform_driver(sdhci_xenon_driver);
541 
542 MODULE_DESCRIPTION("SDHCI platform driver for Marvell Xenon SDHC");
543 MODULE_AUTHOR("Hu Ziji <huziji@marvell.com>");
544 MODULE_LICENSE("GPL v2");
545