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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (C) 2016 Socionext Inc.
  4 *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
  5 */
  6
  7#include <linux/bitfield.h>
  8#include <linux/bits.h>
  9#include <linux/iopoll.h>
 10#include <linux/module.h>
 11#include <linux/mmc/host.h>
 12#include <linux/mmc/mmc.h>
 13#include <linux/of.h>
 14#include <linux/of_device.h>
 15
 16#include "sdhci-pltfm.h"
 17
 18/* HRS - Host Register Set (specific to Cadence) */
 19#define SDHCI_CDNS_HRS04		0x10		/* PHY access port */
 20#define   SDHCI_CDNS_HRS04_ACK			BIT(26)
 21#define   SDHCI_CDNS_HRS04_RD			BIT(25)
 22#define   SDHCI_CDNS_HRS04_WR			BIT(24)
 23#define   SDHCI_CDNS_HRS04_RDATA		GENMASK(23, 16)
 24#define   SDHCI_CDNS_HRS04_WDATA		GENMASK(15, 8)
 25#define   SDHCI_CDNS_HRS04_ADDR			GENMASK(5, 0)
 26
 27#define SDHCI_CDNS_HRS06		0x18		/* eMMC control */
 28#define   SDHCI_CDNS_HRS06_TUNE_UP		BIT(15)
 29#define   SDHCI_CDNS_HRS06_TUNE			GENMASK(13, 8)
 30#define   SDHCI_CDNS_HRS06_MODE			GENMASK(2, 0)
 31#define   SDHCI_CDNS_HRS06_MODE_SD		0x0
 32#define   SDHCI_CDNS_HRS06_MODE_MMC_SDR		0x2
 33#define   SDHCI_CDNS_HRS06_MODE_MMC_DDR		0x3
 34#define   SDHCI_CDNS_HRS06_MODE_MMC_HS200	0x4
 35#define   SDHCI_CDNS_HRS06_MODE_MMC_HS400	0x5
 36#define   SDHCI_CDNS_HRS06_MODE_MMC_HS400ES	0x6
 37
 38/* SRS - Slot Register Set (SDHCI-compatible) */
 39#define SDHCI_CDNS_SRS_BASE		0x200
 40
 41/* PHY */
 42#define SDHCI_CDNS_PHY_DLY_SD_HS	0x00
 43#define SDHCI_CDNS_PHY_DLY_SD_DEFAULT	0x01
 44#define SDHCI_CDNS_PHY_DLY_UHS_SDR12	0x02
 45#define SDHCI_CDNS_PHY_DLY_UHS_SDR25	0x03
 46#define SDHCI_CDNS_PHY_DLY_UHS_SDR50	0x04
 47#define SDHCI_CDNS_PHY_DLY_UHS_DDR50	0x05
 48#define SDHCI_CDNS_PHY_DLY_EMMC_LEGACY	0x06
 49#define SDHCI_CDNS_PHY_DLY_EMMC_SDR	0x07
 50#define SDHCI_CDNS_PHY_DLY_EMMC_DDR	0x08
 51#define SDHCI_CDNS_PHY_DLY_SDCLK	0x0b
 52#define SDHCI_CDNS_PHY_DLY_HSMMC	0x0c
 53#define SDHCI_CDNS_PHY_DLY_STROBE	0x0d
 54
 55/*
 56 * The tuned val register is 6 bit-wide, but not the whole of the range is
 57 * available.  The range 0-42 seems to be available (then 43 wraps around to 0)
 58 * but I am not quite sure if it is official.  Use only 0 to 39 for safety.
 59 */
 60#define SDHCI_CDNS_MAX_TUNING_LOOP	40
 61
 62struct sdhci_cdns_phy_param {
 63	u8 addr;
 64	u8 data;
 65};
 66
 67struct sdhci_cdns_priv {
 68	void __iomem *hrs_addr;
 69	bool enhanced_strobe;
 70	unsigned int nr_phy_params;
 71	struct sdhci_cdns_phy_param phy_params[];
 72};
 73
 74struct sdhci_cdns_phy_cfg {
 75	const char *property;
 76	u8 addr;
 77};
 78
 79static const struct sdhci_cdns_phy_cfg sdhci_cdns_phy_cfgs[] = {
 80	{ "cdns,phy-input-delay-sd-highspeed", SDHCI_CDNS_PHY_DLY_SD_HS, },
 81	{ "cdns,phy-input-delay-legacy", SDHCI_CDNS_PHY_DLY_SD_DEFAULT, },
 82	{ "cdns,phy-input-delay-sd-uhs-sdr12", SDHCI_CDNS_PHY_DLY_UHS_SDR12, },
 83	{ "cdns,phy-input-delay-sd-uhs-sdr25", SDHCI_CDNS_PHY_DLY_UHS_SDR25, },
 84	{ "cdns,phy-input-delay-sd-uhs-sdr50", SDHCI_CDNS_PHY_DLY_UHS_SDR50, },
 85	{ "cdns,phy-input-delay-sd-uhs-ddr50", SDHCI_CDNS_PHY_DLY_UHS_DDR50, },
 86	{ "cdns,phy-input-delay-mmc-highspeed", SDHCI_CDNS_PHY_DLY_EMMC_SDR, },
 87	{ "cdns,phy-input-delay-mmc-ddr", SDHCI_CDNS_PHY_DLY_EMMC_DDR, },
 88	{ "cdns,phy-dll-delay-sdclk", SDHCI_CDNS_PHY_DLY_SDCLK, },
 89	{ "cdns,phy-dll-delay-sdclk-hsmmc", SDHCI_CDNS_PHY_DLY_HSMMC, },
 90	{ "cdns,phy-dll-delay-strobe", SDHCI_CDNS_PHY_DLY_STROBE, },
 91};
 92
 93static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
 94				    u8 addr, u8 data)
 95{
 96	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS04;
 97	u32 tmp;
 98	int ret;
 99
100	ret = readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS04_ACK),
101				 0, 10);
102	if (ret)
103		return ret;
104
105	tmp = FIELD_PREP(SDHCI_CDNS_HRS04_WDATA, data) |
106	      FIELD_PREP(SDHCI_CDNS_HRS04_ADDR, addr);
107	writel(tmp, reg);
108
109	tmp |= SDHCI_CDNS_HRS04_WR;
110	writel(tmp, reg);
111
112	ret = readl_poll_timeout(reg, tmp, tmp & SDHCI_CDNS_HRS04_ACK, 0, 10);
113	if (ret)
114		return ret;
115
116	tmp &= ~SDHCI_CDNS_HRS04_WR;
117	writel(tmp, reg);
118
119	ret = readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS04_ACK),
120				 0, 10);
121
122	return ret;
123}
124
125static unsigned int sdhci_cdns_phy_param_count(struct device_node *np)
126{
127	unsigned int count = 0;
128	int i;
129
130	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++)
131		if (of_property_read_bool(np, sdhci_cdns_phy_cfgs[i].property))
132			count++;
133
134	return count;
135}
136
137static void sdhci_cdns_phy_param_parse(struct device_node *np,
138				       struct sdhci_cdns_priv *priv)
139{
140	struct sdhci_cdns_phy_param *p = priv->phy_params;
141	u32 val;
142	int ret, i;
143
144	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++) {
145		ret = of_property_read_u32(np, sdhci_cdns_phy_cfgs[i].property,
146					   &val);
147		if (ret)
148			continue;
149
150		p->addr = sdhci_cdns_phy_cfgs[i].addr;
151		p->data = val;
152		p++;
153	}
154}
155
156static int sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
157{
158	int ret, i;
159
160	for (i = 0; i < priv->nr_phy_params; i++) {
161		ret = sdhci_cdns_write_phy_reg(priv, priv->phy_params[i].addr,
162					       priv->phy_params[i].data);
163		if (ret)
164			return ret;
165	}
166
167	return 0;
168}
169
170static void *sdhci_cdns_priv(struct sdhci_host *host)
171{
172	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
173
174	return sdhci_pltfm_priv(pltfm_host);
175}
176
177static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
178{
179	/*
180	 * Cadence's spec says the Timeout Clock Frequency is the same as the
181	 * Base Clock Frequency.
182	 */
183	return host->max_clk;
184}
185
186static void sdhci_cdns_set_emmc_mode(struct sdhci_cdns_priv *priv, u32 mode)
187{
188	u32 tmp;
189
190	/* The speed mode for eMMC is selected by HRS06 register */
191	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
192	tmp &= ~SDHCI_CDNS_HRS06_MODE;
193	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_MODE, mode);
194	writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
195}
196
197static u32 sdhci_cdns_get_emmc_mode(struct sdhci_cdns_priv *priv)
198{
199	u32 tmp;
200
201	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
202	return FIELD_GET(SDHCI_CDNS_HRS06_MODE, tmp);
203}
204
205static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val)
206{
207	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
208	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS06;
209	u32 tmp;
210	int i, ret;
211
212	if (WARN_ON(!FIELD_FIT(SDHCI_CDNS_HRS06_TUNE, val)))
213		return -EINVAL;
214
215	tmp = readl(reg);
216	tmp &= ~SDHCI_CDNS_HRS06_TUNE;
217	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_TUNE, val);
218
219	/*
220	 * Workaround for IP errata:
221	 * The IP6116 SD/eMMC PHY design has a timing issue on receive data
222	 * path. Send tune request twice.
223	 */
224	for (i = 0; i < 2; i++) {
225		tmp |= SDHCI_CDNS_HRS06_TUNE_UP;
226		writel(tmp, reg);
227
228		ret = readl_poll_timeout(reg, tmp,
229					 !(tmp & SDHCI_CDNS_HRS06_TUNE_UP),
230					 0, 1);
231		if (ret)
232			return ret;
233	}
234
235	return 0;
236}
237
238/*
239 * In SD mode, software must not use the hardware tuning and instead perform
240 * an almost identical procedure to eMMC.
241 */
242static int sdhci_cdns_execute_tuning(struct sdhci_host *host, u32 opcode)
243{
244	int cur_streak = 0;
245	int max_streak = 0;
246	int end_of_streak = 0;
247	int i;
248
249	/*
250	 * Do not execute tuning for UHS_SDR50 or UHS_DDR50.
251	 * The delay is set by probe, based on the DT properties.
252	 */
253	if (host->timing != MMC_TIMING_MMC_HS200 &&
254	    host->timing != MMC_TIMING_UHS_SDR104)
255		return 0;
256
257	for (i = 0; i < SDHCI_CDNS_MAX_TUNING_LOOP; i++) {
258		if (sdhci_cdns_set_tune_val(host, i) ||
259		    mmc_send_tuning(host->mmc, opcode, NULL)) { /* bad */
260			cur_streak = 0;
261		} else { /* good */
262			cur_streak++;
263			if (cur_streak > max_streak) {
264				max_streak = cur_streak;
265				end_of_streak = i;
266			}
267		}
268	}
269
270	if (!max_streak) {
271		dev_err(mmc_dev(host->mmc), "no tuning point found\n");
272		return -EIO;
273	}
274
275	return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2);
276}
277
278static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
279					 unsigned int timing)
280{
281	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
282	u32 mode;
283
284	switch (timing) {
285	case MMC_TIMING_MMC_HS:
286		mode = SDHCI_CDNS_HRS06_MODE_MMC_SDR;
287		break;
288	case MMC_TIMING_MMC_DDR52:
289		mode = SDHCI_CDNS_HRS06_MODE_MMC_DDR;
290		break;
291	case MMC_TIMING_MMC_HS200:
292		mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200;
293		break;
294	case MMC_TIMING_MMC_HS400:
295		if (priv->enhanced_strobe)
296			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400ES;
297		else
298			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
299		break;
300	default:
301		mode = SDHCI_CDNS_HRS06_MODE_SD;
302		break;
303	}
304
305	sdhci_cdns_set_emmc_mode(priv, mode);
306
307	/* For SD, fall back to the default handler */
308	if (mode == SDHCI_CDNS_HRS06_MODE_SD)
309		sdhci_set_uhs_signaling(host, timing);
310}
311
312static const struct sdhci_ops sdhci_cdns_ops = {
313	.set_clock = sdhci_set_clock,
314	.get_timeout_clock = sdhci_cdns_get_timeout_clock,
315	.set_bus_width = sdhci_set_bus_width,
316	.reset = sdhci_reset,
317	.platform_execute_tuning = sdhci_cdns_execute_tuning,
318	.set_uhs_signaling = sdhci_cdns_set_uhs_signaling,
319};
320
321static const struct sdhci_pltfm_data sdhci_cdns_uniphier_pltfm_data = {
322	.ops = &sdhci_cdns_ops,
323	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
324};
325
326static const struct sdhci_pltfm_data sdhci_cdns_pltfm_data = {
327	.ops = &sdhci_cdns_ops,
328};
329
330static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
331					     struct mmc_ios *ios)
332{
333	struct sdhci_host *host = mmc_priv(mmc);
334	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
335	u32 mode;
336
337	priv->enhanced_strobe = ios->enhanced_strobe;
338
339	mode = sdhci_cdns_get_emmc_mode(priv);
340
341	if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400 && ios->enhanced_strobe)
342		sdhci_cdns_set_emmc_mode(priv,
343					 SDHCI_CDNS_HRS06_MODE_MMC_HS400ES);
344
345	if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400ES && !ios->enhanced_strobe)
346		sdhci_cdns_set_emmc_mode(priv,
347					 SDHCI_CDNS_HRS06_MODE_MMC_HS400);
348}
349
350static int sdhci_cdns_probe(struct platform_device *pdev)
351{
352	struct sdhci_host *host;
353	const struct sdhci_pltfm_data *data;
354	struct sdhci_pltfm_host *pltfm_host;
355	struct sdhci_cdns_priv *priv;
356	struct clk *clk;
357	unsigned int nr_phy_params;
358	int ret;
359	struct device *dev = &pdev->dev;
360	static const u16 version = SDHCI_SPEC_400 << SDHCI_SPEC_VER_SHIFT;
361
362	clk = devm_clk_get(dev, NULL);
363	if (IS_ERR(clk))
364		return PTR_ERR(clk);
365
366	ret = clk_prepare_enable(clk);
367	if (ret)
368		return ret;
369
370	data = of_device_get_match_data(dev);
371	if (!data)
372		data = &sdhci_cdns_pltfm_data;
373
374	nr_phy_params = sdhci_cdns_phy_param_count(dev->of_node);
375	host = sdhci_pltfm_init(pdev, data,
376				struct_size(priv, phy_params, nr_phy_params));
377	if (IS_ERR(host)) {
378		ret = PTR_ERR(host);
379		goto disable_clk;
380	}
381
382	pltfm_host = sdhci_priv(host);
383	pltfm_host->clk = clk;
384
385	priv = sdhci_pltfm_priv(pltfm_host);
386	priv->nr_phy_params = nr_phy_params;
387	priv->hrs_addr = host->ioaddr;
388	priv->enhanced_strobe = false;
389	host->ioaddr += SDHCI_CDNS_SRS_BASE;
390	host->mmc_host_ops.hs400_enhanced_strobe =
391				sdhci_cdns_hs400_enhanced_strobe;
392	sdhci_enable_v4_mode(host);
393	__sdhci_read_caps(host, &version, NULL, NULL);
394
395	sdhci_get_of_property(pdev);
396
397	ret = mmc_of_parse(host->mmc);
398	if (ret)
399		goto free;
400
401	sdhci_cdns_phy_param_parse(dev->of_node, priv);
402
403	ret = sdhci_cdns_phy_init(priv);
404	if (ret)
405		goto free;
406
407	ret = sdhci_add_host(host);
408	if (ret)
409		goto free;
410
411	return 0;
412free:
413	sdhci_pltfm_free(pdev);
414disable_clk:
415	clk_disable_unprepare(clk);
416
417	return ret;
418}
419
420#ifdef CONFIG_PM_SLEEP
421static int sdhci_cdns_resume(struct device *dev)
422{
423	struct sdhci_host *host = dev_get_drvdata(dev);
424	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
425	struct sdhci_cdns_priv *priv = sdhci_pltfm_priv(pltfm_host);
426	int ret;
427
428	ret = clk_prepare_enable(pltfm_host->clk);
429	if (ret)
430		return ret;
431
432	ret = sdhci_cdns_phy_init(priv);
433	if (ret)
434		goto disable_clk;
435
436	ret = sdhci_resume_host(host);
437	if (ret)
438		goto disable_clk;
439
440	return 0;
441
442disable_clk:
443	clk_disable_unprepare(pltfm_host->clk);
444
445	return ret;
446}
447#endif
448
449static const struct dev_pm_ops sdhci_cdns_pm_ops = {
450	SET_SYSTEM_SLEEP_PM_OPS(sdhci_pltfm_suspend, sdhci_cdns_resume)
451};
452
453static const struct of_device_id sdhci_cdns_match[] = {
454	{
455		.compatible = "socionext,uniphier-sd4hc",
456		.data = &sdhci_cdns_uniphier_pltfm_data,
457	},
458	{ .compatible = "cdns,sd4hc" },
459	{ /* sentinel */ }
460};
461MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
462
463static struct platform_driver sdhci_cdns_driver = {
464	.driver = {
465		.name = "sdhci-cdns",
466		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
467		.pm = &sdhci_cdns_pm_ops,
468		.of_match_table = sdhci_cdns_match,
469	},
470	.probe = sdhci_cdns_probe,
471	.remove = sdhci_pltfm_unregister,
472};
473module_platform_driver(sdhci_cdns_driver);
474
475MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
476MODULE_DESCRIPTION("Cadence SD/SDIO/eMMC Host Controller Driver");
477MODULE_LICENSE("GPL");