summaryrefslogtreecommitdiffstats
path: root/drivers/mmc/host/sdhci-of-at91.c
blob: 2703aa90d0185342ee7586474221de69c0dcdcc7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
/*
 * Atmel SDMMC controller driver.
 *
 * Copyright (C) 2015 Atmel,
 *		 2015 Ludovic Desroches <ludovic.desroches@atmel.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/mmc/host.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>

#include "sdhci-pltfm.h"

#define SDMMC_CACR	0x230
#define		SDMMC_CACR_CAPWREN	BIT(0)
#define		SDMMC_CACR_KEY		(0x46 << 8)

struct sdhci_at91_priv {
	struct clk *hclock;
	struct clk *gck;
	struct clk *mainck;
};

static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
	.set_clock		= sdhci_set_clock,
	.set_bus_width		= sdhci_set_bus_width,
	.reset			= sdhci_reset,
	.set_uhs_signaling	= sdhci_set_uhs_signaling,
};

static const struct sdhci_pltfm_data soc_data_sama5d2 = {
	.ops = &sdhci_at91_sama5d2_ops,
	.quirks2 = SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST,
};

static const struct of_device_id sdhci_at91_dt_match[] = {
	{ .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 },
	{}
};

#ifdef CONFIG_PM
static int sdhci_at91_runtime_suspend(struct device *dev)
{
	struct sdhci_host *host = dev_get_drvdata(dev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
	int ret;

	ret = sdhci_runtime_suspend_host(host);

	clk_disable_unprepare(priv->gck);
	clk_disable_unprepare(priv->hclock);
	clk_disable_unprepare(priv->mainck);

	return ret;
}

static int sdhci_at91_runtime_resume(struct device *dev)
{
	struct sdhci_host *host = dev_get_drvdata(dev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
	int ret;

	ret = clk_prepare_enable(priv->mainck);
	if (ret) {
		dev_err(dev, "can't enable mainck\n");
		return ret;
	}

	ret = clk_prepare_enable(priv->hclock);
	if (ret) {
		dev_err(dev, "can't enable hclock\n");
		return ret;
	}

	ret = clk_prepare_enable(priv->gck);
	if (ret) {
		dev_err(dev, "can't enable gck\n");
		return ret;
	}

	return sdhci_runtime_resume_host(host);
}
#endif /* CONFIG_PM */

static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
				pm_runtime_force_resume)
	SET_RUNTIME_PM_OPS(sdhci_at91_runtime_suspend,
			   sdhci_at91_runtime_resume,
			   NULL)
};

static int sdhci_at91_probe(struct platform_device *pdev)
{
	const struct of_device_id	*match;
	const struct sdhci_pltfm_data	*soc_data;
	struct sdhci_host		*host;
	struct sdhci_pltfm_host		*pltfm_host;
	struct sdhci_at91_priv		*priv;
	unsigned int			caps0, caps1;
	unsigned int			clk_base, clk_mul;
	unsigned int			gck_rate, real_gck_rate;
	int				ret;

	match = of_match_device(sdhci_at91_dt_match, &pdev->dev);
	if (!match)
		return -EINVAL;
	soc_data = match->data;

	host = sdhci_pltfm_init(pdev, soc_data, sizeof(*priv));
	if (IS_ERR(host))
		return PTR_ERR(host);

	pltfm_host = sdhci_priv(host);
	priv = sdhci_pltfm_priv(pltfm_host);

	priv->mainck = devm_clk_get(&pdev->dev, "baseclk");
	if (IS_ERR(priv->mainck)) {
		dev_err(&pdev->dev, "failed to get baseclk\n");
		return PTR_ERR(priv->mainck);
	}

	priv->hclock = devm_clk_get(&pdev->dev, "hclock");
	if (IS_ERR(priv->hclock)) {
		dev_err(&pdev->dev, "failed to get hclock\n");
		return PTR_ERR(priv->hclock);
	}

	priv->gck = devm_clk_get(&pdev->dev, "multclk");
	if (IS_ERR(priv->gck)) {
		dev_err(&pdev->dev, "failed to get multclk\n");
		return PTR_ERR(priv->gck);
	}

	/*
	 * The mult clock is provided by as a generated clock by the PMC
	 * controller. In order to set the rate of gck, we have to get the
	 * base clock rate and the clock mult from capabilities.
	 */
	clk_prepare_enable(priv->hclock);
	caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
	caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
	clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
	clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT;
	gck_rate = clk_base * 1000000 * (clk_mul + 1);
	ret = clk_set_rate(priv->gck, gck_rate);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to set gck");
		goto hclock_disable_unprepare;
	}
	/*
	 * We need to check if we have the requested rate for gck because in
	 * some cases this rate could be not supported. If it happens, the rate
	 * is the closest one gck can provide. We have to update the value
	 * of clk mul.
	 */
	real_gck_rate = clk_get_rate(priv->gck);
	if (real_gck_rate != gck_rate) {
		clk_mul = real_gck_rate / (clk_base * 1000000) - 1;
		caps1 &= (~SDHCI_CLOCK_MUL_MASK);
		caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) & SDHCI_CLOCK_MUL_MASK);
		/* Set capabilities in r/w mode. */
		writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN, host->ioaddr + SDMMC_CACR);
		writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
		/* Set capabilities in ro mode. */
		writel(0, host->ioaddr + SDMMC_CACR);
		dev_info(&pdev->dev, "update clk mul to %u as gck rate is %u Hz\n",
			 clk_mul, real_gck_rate);
	}

	clk_prepare_enable(priv->mainck);
	clk_prepare_enable(priv->gck);

	ret = mmc_of_parse(host->mmc);
	if (ret)
		goto clocks_disable_unprepare;

	sdhci_get_of_property(pdev);

	pm_runtime_get_noresume(&pdev->dev);
	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);
	pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
	pm_runtime_use_autosuspend(&pdev->dev);

	ret = sdhci_add_host(host);
	if (ret)
		goto pm_runtime_disable;

	/*
	 * When calling sdhci_runtime_suspend_host(), the sdhci layer makes
	 * the assumption that all the clocks of the controller are disabled.
	 * It means we can't get irq from it when it is runtime suspended.
	 * For that reason, it is not planned to wake-up on a card detect irq
	 * from the controller.
	 * If we want to use runtime PM and to be able to wake-up on card
	 * insertion, we have to use a GPIO for the card detection or we can
	 * use polling. Be aware that using polling will resume/suspend the
	 * controller between each attempt.
	 * Disable SDHCI_QUIRK_BROKEN_CARD_DETECTION to be sure nobody tries
	 * to enable polling via device tree with broken-cd property.
	 */
	if (!(host->mmc->caps & MMC_CAP_NONREMOVABLE) &&
	    IS_ERR_VALUE(mmc_gpio_get_cd(host->mmc))) {
		host->mmc->caps |= MMC_CAP_NEEDS_POLL;
		host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
	}

	pm_runtime_put_autosuspend(&pdev->dev);

	return 0;

pm_runtime_disable:
	pm_runtime_disable(&pdev->dev);
	pm_runtime_set_suspended(&pdev->dev);
	pm_runtime_put_noidle(&pdev->dev);
clocks_disable_unprepare:
	clk_disable_unprepare(priv->gck);
	clk_disable_unprepare(priv->mainck);
hclock_disable_unprepare:
	clk_disable_unprepare(priv->hclock);
	sdhci_pltfm_free(pdev);
	return ret;
}

static int sdhci_at91_remove(struct platform_device *pdev)
{
	struct sdhci_host	*host = platform_get_drvdata(pdev);
	struct sdhci_pltfm_host	*pltfm_host = sdhci_priv(host);
	struct sdhci_at91_priv	*priv = sdhci_pltfm_priv(pltfm_host);
	struct clk *gck = priv->gck;
	struct clk *hclock = priv->hclock;
	struct clk *mainck = priv->mainck;

	pm_runtime_get_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	pm_runtime_put_noidle(&pdev->dev);

	sdhci_pltfm_unregister(pdev);

	clk_disable_unprepare(gck);
	clk_disable_unprepare(hclock);
	clk_disable_unprepare(mainck);

	return 0;
}

static struct platform_driver sdhci_at91_driver = {
	.driver		= {
		.name	= "sdhci-at91",
		.of_match_table = sdhci_at91_dt_match,
		.pm	= &sdhci_at91_dev_pm_ops,
	},
	.probe		= sdhci_at91_probe,
	.remove		= sdhci_at91_remove,
};

module_platform_driver(sdhci_at91_driver);

MODULE_DESCRIPTION("SDHCI driver for at91");
MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@atmel.com>");
MODULE_LICENSE("GPL v2");
OpenPOWER on IntegriCloud