summaryrefslogtreecommitdiff
path: root/drivers/mmc/host/sdhci-bcm-kona.c
blob: 90a936732925edce366c009ca42ce206a9cabdf7 (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
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
/*
 * Copyright (C) 2013 Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/highmem.h>
#include <linux/platform_device.h>
#include <linux/mmc/host.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/clk.h>
#include <linux/regulator/consumer.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/version.h>
#include <linux/mmc/slot-gpio.h>

#include "sdhci-pltfm.h"
#include "sdhci.h"

#define SDHCI_SOFT_RESET			0x01000000
#define KONA_SDHOST_CORECTRL			0x8000
#define KONA_SDHOST_CD_PINCTRL			0x00000008
#define KONA_SDHOST_STOP_HCLK			0x00000004
#define KONA_SDHOST_RESET			0x00000002
#define KONA_SDHOST_EN				0x00000001

#define KONA_SDHOST_CORESTAT			0x8004
#define KONA_SDHOST_WP				0x00000002
#define KONA_SDHOST_CD_SW			0x00000001

#define KONA_SDHOST_COREIMR			0x8008
#define KONA_SDHOST_IP				0x00000001

#define KONA_SDHOST_COREISR			0x800C
#define KONA_SDHOST_COREIMSR			0x8010
#define KONA_SDHOST_COREDBG1			0x8014
#define KONA_SDHOST_COREGPO_MASK		0x8018

#define SD_DETECT_GPIO_DEBOUNCE_128MS		128

#define KONA_MMC_AUTOSUSPEND_DELAY		(50)

struct sdhci_bcm_kona_dev {
	struct mutex	write_lock; /* protect back to back writes */
};


static int sdhci_bcm_kona_sd_reset(struct sdhci_host *host)
{
	unsigned int val;
	unsigned long timeout;

	/* This timeout should be sufficent for core to reset */
	timeout = jiffies + msecs_to_jiffies(100);

	/* reset the host using the top level reset */
	val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
	val |= KONA_SDHOST_RESET;
	sdhci_writel(host, val, KONA_SDHOST_CORECTRL);

	while (!(sdhci_readl(host, KONA_SDHOST_CORECTRL) & KONA_SDHOST_RESET)) {
		if (time_is_before_jiffies(timeout)) {
			pr_err("Error: sd host is stuck in reset!!!\n");
			return -EFAULT;
		}
	}

	/* bring the host out of reset */
	val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
	val &= ~KONA_SDHOST_RESET;

	/*
	 * Back-to-Back register write needs a delay of 1ms at bootup (min 10uS)
	 * Back-to-Back writes to same register needs delay when SD bus clock
	 * is very low w.r.t AHB clock, mainly during boot-time and during card
	 * insert-removal.
	 */
	usleep_range(1000, 5000);
	sdhci_writel(host, val, KONA_SDHOST_CORECTRL);

	return 0;
}

static void sdhci_bcm_kona_sd_init(struct sdhci_host *host)
{
	unsigned int val;

	/* enable the interrupt from the IP core */
	val = sdhci_readl(host, KONA_SDHOST_COREIMR);
	val |= KONA_SDHOST_IP;
	sdhci_writel(host, val, KONA_SDHOST_COREIMR);

	/* Enable the AHB clock gating module to the host */
	val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
	val |= KONA_SDHOST_EN;

	/*
	 * Back-to-Back register write needs a delay of 1ms at bootup (min 10uS)
	 * Back-to-Back writes to same register needs delay when SD bus clock
	 * is very low w.r.t AHB clock, mainly during boot-time and during card
	 * insert-removal.
	 */
	usleep_range(1000, 5000);
	sdhci_writel(host, val, KONA_SDHOST_CORECTRL);
}

/*
 * Software emulation of the SD card insertion/removal. Set insert=1 for insert
 * and insert=0 for removal. The card detection is done by GPIO. For Broadcom
 * IP to function properly the bit 0 of CORESTAT register needs to be set/reset
 * to generate the CD IRQ handled in sdhci.c which schedules card_tasklet.
 */
static int sdhci_bcm_kona_sd_card_emulate(struct sdhci_host *host, int insert)
{
	struct sdhci_pltfm_host *pltfm_priv = sdhci_priv(host);
	struct sdhci_bcm_kona_dev *kona_dev = sdhci_pltfm_priv(pltfm_priv);
	u32 val;

	/*
	 * Back-to-Back register write needs a delay of min 10uS.
	 * Back-to-Back writes to same register needs delay when SD bus clock
	 * is very low w.r.t AHB clock, mainly during boot-time and during card
	 * insert-removal.
	 * We keep 20uS
	 */
	mutex_lock(&kona_dev->write_lock);
	udelay(20);
	val = sdhci_readl(host, KONA_SDHOST_CORESTAT);

	if (insert) {
		int ret;

		ret = mmc_gpio_get_ro(host->mmc);
		if (ret >= 0)
			val = (val & ~KONA_SDHOST_WP) |
				((ret) ? KONA_SDHOST_WP : 0);

		val |= KONA_SDHOST_CD_SW;
		sdhci_writel(host, val, KONA_SDHOST_CORESTAT);
	} else {
		val &= ~KONA_SDHOST_CD_SW;
		sdhci_writel(host, val, KONA_SDHOST_CORESTAT);
	}
	mutex_unlock(&kona_dev->write_lock);

	return 0;
}

/*
 * SD card interrupt event callback
 */
void sdhci_bcm_kona_card_event(struct sdhci_host *host)
{
	if (mmc_gpio_get_cd(host->mmc) > 0) {
		dev_dbg(mmc_dev(host->mmc),
			"card inserted\n");
		sdhci_bcm_kona_sd_card_emulate(host, 1);
	} else {
		dev_dbg(mmc_dev(host->mmc),
			"card removed\n");
		sdhci_bcm_kona_sd_card_emulate(host, 0);
	}
}

/*
 * Get the base clock. Use central clock source for now. Not sure if different
 * clock speed to each dev is allowed
 */
static unsigned int sdhci_bcm_kona_get_max_clk(struct sdhci_host *host)
{
	struct sdhci_bcm_kona_dev *kona_dev;
	struct sdhci_pltfm_host *pltfm_priv = sdhci_priv(host);
	kona_dev = sdhci_pltfm_priv(pltfm_priv);

	return host->mmc->f_max;
}

static unsigned int sdhci_bcm_kona_get_timeout_clock(struct sdhci_host *host)
{
	return sdhci_bcm_kona_get_max_clk(host);
}

static void sdhci_bcm_kona_init_74_clocks(struct sdhci_host *host,
				u8 power_mode)
{
	/*
	 *  JEDEC and SD spec specify supplying 74 continuous clocks to
	 * device after power up. With minimum bus (100KHz) that
	 * that translates to 740us
	 */
	if (power_mode != MMC_POWER_OFF)
		udelay(740);
}

static struct sdhci_ops sdhci_bcm_kona_ops = {
	.get_max_clock = sdhci_bcm_kona_get_max_clk,
	.get_timeout_clock = sdhci_bcm_kona_get_timeout_clock,
	.platform_send_init_74_clocks = sdhci_bcm_kona_init_74_clocks,
	.card_event = sdhci_bcm_kona_card_event,
};

static struct sdhci_pltfm_data sdhci_pltfm_data_kona = {
	.ops    = &sdhci_bcm_kona_ops,
	.quirks = SDHCI_QUIRK_NO_CARD_NO_RESET |
		SDHCI_QUIRK_BROKEN_TIMEOUT_VAL | SDHCI_QUIRK_32BIT_DMA_ADDR |
		SDHCI_QUIRK_32BIT_DMA_SIZE | SDHCI_QUIRK_32BIT_ADMA_SIZE |
		SDHCI_QUIRK_FORCE_BLK_SZ_2048 |
		SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
};

static struct __initconst of_device_id sdhci_bcm_kona_of_match[] = {
	{ .compatible = "bcm,kona-sdhci"},
	{}
};
MODULE_DEVICE_TABLE(of, sdhci_bcm_kona_of_match);

static int sdhci_bcm_kona_probe(struct platform_device *pdev)
{
	struct sdhci_bcm_kona_dev *kona_dev = NULL;
	struct sdhci_pltfm_host *pltfm_priv;
	struct device *dev = &pdev->dev;
	struct sdhci_host *host;
	int ret;

	ret = 0;

	host = sdhci_pltfm_init(pdev, &sdhci_pltfm_data_kona,
			sizeof(*kona_dev));
	if (IS_ERR(host))
		return PTR_ERR(host);

	dev_dbg(dev, "%s: inited. IOADDR=%p\n", __func__, host->ioaddr);

	pltfm_priv = sdhci_priv(host);

	kona_dev = sdhci_pltfm_priv(pltfm_priv);
	mutex_init(&kona_dev->write_lock);

	mmc_of_parse(host->mmc);

	if (!host->mmc->f_max) {
		dev_err(&pdev->dev, "Missing max-freq for SDHCI cfg\n");
		ret = -ENXIO;
		goto err_pltfm_free;
	}

	dev_dbg(dev, "non-removable=%c\n",
		(host->mmc->caps & MMC_CAP_NONREMOVABLE) ? 'Y' : 'N');
	dev_dbg(dev, "cd_gpio %c, wp_gpio %c\n",
		(mmc_gpio_get_cd(host->mmc) != -ENOSYS) ? 'Y' : 'N',
		(mmc_gpio_get_ro(host->mmc) != -ENOSYS) ? 'Y' : 'N');

	if (host->mmc->caps & MMC_CAP_NONREMOVABLE)
		host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;

	dev_dbg(dev, "is_8bit=%c\n",
		(host->mmc->caps | MMC_CAP_8_BIT_DATA) ? 'Y' : 'N');

	ret = sdhci_bcm_kona_sd_reset(host);
	if (ret)
		goto err_pltfm_free;

	sdhci_bcm_kona_sd_init(host);

	ret = sdhci_add_host(host);
	if (ret) {
		dev_err(dev, "Failed sdhci_add_host\n");
		goto err_reset;
	}

	/* if device is eMMC, emulate card insert right here */
	if (host->mmc->caps & MMC_CAP_NONREMOVABLE) {
		ret = sdhci_bcm_kona_sd_card_emulate(host, 1);
		if (ret) {
			dev_err(dev,
				"unable to emulate card insertion\n");
			goto err_remove_host;
		}
	}
	/*
	 * Since the card detection GPIO interrupt is configured to be
	 * edge sensitive, check the initial GPIO value here, emulate
	 * only if the card is present
	 */
	if (mmc_gpio_get_cd(host->mmc) > 0)
		sdhci_bcm_kona_sd_card_emulate(host, 1);

	dev_dbg(dev, "initialized properly\n");
	return 0;

err_remove_host:
	sdhci_remove_host(host, 0);

err_reset:
	sdhci_bcm_kona_sd_reset(host);

err_pltfm_free:
	sdhci_pltfm_free(pdev);

	dev_err(dev, "Probing of sdhci-pltfm failed: %d\n", ret);
	return ret;
}

static int __exit sdhci_bcm_kona_remove(struct platform_device *pdev)
{
	struct sdhci_host *host = platform_get_drvdata(pdev);
	int dead;
	u32 scratch;

	dead = 0;
	scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
	if (scratch == (u32)-1)
		dead = 1;
	sdhci_remove_host(host, dead);

	sdhci_free_host(host);

	return 0;
}

static struct platform_driver sdhci_bcm_kona_driver = {
	.driver		= {
		.name	= "sdhci-kona",
		.owner	= THIS_MODULE,
		.pm	= SDHCI_PLTFM_PMOPS,
		.of_match_table = sdhci_bcm_kona_of_match,
	},
	.probe		= sdhci_bcm_kona_probe,
	.remove		= sdhci_bcm_kona_remove,
};
module_platform_driver(sdhci_bcm_kona_driver);

MODULE_DESCRIPTION("SDHCI driver for Broadcom Kona platform");
MODULE_AUTHOR("Broadcom");
MODULE_LICENSE("GPL v2");