1 /*
2 * Copyright (C) 2013 Broadcom Corporation
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation version 2.
7 *
8 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9 * kind, whether express or implied; without even the implied warranty
10 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/delay.h>
17 #include <linux/highmem.h>
18 #include <linux/platform_device.h>
19 #include <linux/mmc/host.h>
20 #include <linux/io.h>
21 #include <linux/clk.h>
22 #include <linux/regulator/consumer.h>
23 #include <linux/of.h>
24 #include <linux/of_device.h>
25 #include <linux/mmc/slot-gpio.h>
26
27 #include "sdhci-pltfm.h"
28 #include "sdhci.h"
29
30 #define SDHCI_SOFT_RESET 0x01000000
31 #define KONA_SDHOST_CORECTRL 0x8000
32 #define KONA_SDHOST_CD_PINCTRL 0x00000008
33 #define KONA_SDHOST_STOP_HCLK 0x00000004
34 #define KONA_SDHOST_RESET 0x00000002
35 #define KONA_SDHOST_EN 0x00000001
36
37 #define KONA_SDHOST_CORESTAT 0x8004
38 #define KONA_SDHOST_WP 0x00000002
39 #define KONA_SDHOST_CD_SW 0x00000001
40
41 #define KONA_SDHOST_COREIMR 0x8008
42 #define KONA_SDHOST_IP 0x00000001
43
44 #define KONA_SDHOST_COREISR 0x800C
45 #define KONA_SDHOST_COREIMSR 0x8010
46 #define KONA_SDHOST_COREDBG1 0x8014
47 #define KONA_SDHOST_COREGPO_MASK 0x8018
48
49 #define SD_DETECT_GPIO_DEBOUNCE_128MS 128
50
51 #define KONA_MMC_AUTOSUSPEND_DELAY (50)
52
53 struct sdhci_bcm_kona_dev {
54 struct mutex write_lock; /* protect back to back writes */
55 };
56
57
sdhci_bcm_kona_sd_reset(struct sdhci_host * host)58 static int sdhci_bcm_kona_sd_reset(struct sdhci_host *host)
59 {
60 unsigned int val;
61 unsigned long timeout;
62
63 /* This timeout should be sufficent for core to reset */
64 timeout = jiffies + msecs_to_jiffies(100);
65
66 /* reset the host using the top level reset */
67 val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
68 val |= KONA_SDHOST_RESET;
69 sdhci_writel(host, val, KONA_SDHOST_CORECTRL);
70
71 while (!(sdhci_readl(host, KONA_SDHOST_CORECTRL) & KONA_SDHOST_RESET)) {
72 if (time_is_before_jiffies(timeout)) {
73 pr_err("Error: sd host is stuck in reset!!!\n");
74 return -EFAULT;
75 }
76 }
77
78 /* bring the host out of reset */
79 val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
80 val &= ~KONA_SDHOST_RESET;
81
82 /*
83 * Back-to-Back register write needs a delay of 1ms at bootup (min 10uS)
84 * Back-to-Back writes to same register needs delay when SD bus clock
85 * is very low w.r.t AHB clock, mainly during boot-time and during card
86 * insert-removal.
87 */
88 usleep_range(1000, 5000);
89 sdhci_writel(host, val, KONA_SDHOST_CORECTRL);
90
91 return 0;
92 }
93
sdhci_bcm_kona_sd_init(struct sdhci_host * host)94 static void sdhci_bcm_kona_sd_init(struct sdhci_host *host)
95 {
96 unsigned int val;
97
98 /* enable the interrupt from the IP core */
99 val = sdhci_readl(host, KONA_SDHOST_COREIMR);
100 val |= KONA_SDHOST_IP;
101 sdhci_writel(host, val, KONA_SDHOST_COREIMR);
102
103 /* Enable the AHB clock gating module to the host */
104 val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
105 val |= KONA_SDHOST_EN;
106
107 /*
108 * Back-to-Back register write needs a delay of 1ms at bootup (min 10uS)
109 * Back-to-Back writes to same register needs delay when SD bus clock
110 * is very low w.r.t AHB clock, mainly during boot-time and during card
111 * insert-removal.
112 */
113 usleep_range(1000, 5000);
114 sdhci_writel(host, val, KONA_SDHOST_CORECTRL);
115 }
116
117 /*
118 * Software emulation of the SD card insertion/removal. Set insert=1 for insert
119 * and insert=0 for removal. The card detection is done by GPIO. For Broadcom
120 * IP to function properly the bit 0 of CORESTAT register needs to be set/reset
121 * to generate the CD IRQ handled in sdhci.c which schedules card_tasklet.
122 */
sdhci_bcm_kona_sd_card_emulate(struct sdhci_host * host,int insert)123 static int sdhci_bcm_kona_sd_card_emulate(struct sdhci_host *host, int insert)
124 {
125 struct sdhci_pltfm_host *pltfm_priv = sdhci_priv(host);
126 struct sdhci_bcm_kona_dev *kona_dev = sdhci_pltfm_priv(pltfm_priv);
127 u32 val;
128
129 /*
130 * Back-to-Back register write needs a delay of min 10uS.
131 * Back-to-Back writes to same register needs delay when SD bus clock
132 * is very low w.r.t AHB clock, mainly during boot-time and during card
133 * insert-removal.
134 * We keep 20uS
135 */
136 mutex_lock(&kona_dev->write_lock);
137 udelay(20);
138 val = sdhci_readl(host, KONA_SDHOST_CORESTAT);
139
140 if (insert) {
141 int ret;
142
143 ret = mmc_gpio_get_ro(host->mmc);
144 if (ret >= 0)
145 val = (val & ~KONA_SDHOST_WP) |
146 ((ret) ? KONA_SDHOST_WP : 0);
147
148 val |= KONA_SDHOST_CD_SW;
149 sdhci_writel(host, val, KONA_SDHOST_CORESTAT);
150 } else {
151 val &= ~KONA_SDHOST_CD_SW;
152 sdhci_writel(host, val, KONA_SDHOST_CORESTAT);
153 }
154 mutex_unlock(&kona_dev->write_lock);
155
156 return 0;
157 }
158
159 /*
160 * SD card interrupt event callback
161 */
sdhci_bcm_kona_card_event(struct sdhci_host * host)162 static void sdhci_bcm_kona_card_event(struct sdhci_host *host)
163 {
164 if (mmc_gpio_get_cd(host->mmc) > 0) {
165 dev_dbg(mmc_dev(host->mmc),
166 "card inserted\n");
167 sdhci_bcm_kona_sd_card_emulate(host, 1);
168 } else {
169 dev_dbg(mmc_dev(host->mmc),
170 "card removed\n");
171 sdhci_bcm_kona_sd_card_emulate(host, 0);
172 }
173 }
174
sdhci_bcm_kona_init_74_clocks(struct sdhci_host * host,u8 power_mode)175 static void sdhci_bcm_kona_init_74_clocks(struct sdhci_host *host,
176 u8 power_mode)
177 {
178 /*
179 * JEDEC and SD spec specify supplying 74 continuous clocks to
180 * device after power up. With minimum bus (100KHz) that
181 * that translates to 740us
182 */
183 if (power_mode != MMC_POWER_OFF)
184 udelay(740);
185 }
186
187 static const struct sdhci_ops sdhci_bcm_kona_ops = {
188 .set_clock = sdhci_set_clock,
189 .get_max_clock = sdhci_pltfm_clk_get_max_clock,
190 .get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
191 .platform_send_init_74_clocks = sdhci_bcm_kona_init_74_clocks,
192 .set_bus_width = sdhci_set_bus_width,
193 .reset = sdhci_reset,
194 .set_uhs_signaling = sdhci_set_uhs_signaling,
195 .card_event = sdhci_bcm_kona_card_event,
196 };
197
198 static const struct sdhci_pltfm_data sdhci_pltfm_data_kona = {
199 .ops = &sdhci_bcm_kona_ops,
200 .quirks = SDHCI_QUIRK_NO_CARD_NO_RESET |
201 SDHCI_QUIRK_BROKEN_TIMEOUT_VAL | SDHCI_QUIRK_32BIT_DMA_ADDR |
202 SDHCI_QUIRK_32BIT_DMA_SIZE | SDHCI_QUIRK_32BIT_ADMA_SIZE |
203 SDHCI_QUIRK_FORCE_BLK_SZ_2048 |
204 SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
205 };
206
207 static const struct of_device_id sdhci_bcm_kona_of_match[] = {
208 { .compatible = "brcm,kona-sdhci"},
209 { .compatible = "bcm,kona-sdhci"}, /* deprecated name */
210 {}
211 };
212 MODULE_DEVICE_TABLE(of, sdhci_bcm_kona_of_match);
213
sdhci_bcm_kona_probe(struct platform_device * pdev)214 static int sdhci_bcm_kona_probe(struct platform_device *pdev)
215 {
216 struct sdhci_bcm_kona_dev *kona_dev = NULL;
217 struct sdhci_pltfm_host *pltfm_priv;
218 struct device *dev = &pdev->dev;
219 struct sdhci_host *host;
220 int ret;
221
222 ret = 0;
223
224 host = sdhci_pltfm_init(pdev, &sdhci_pltfm_data_kona,
225 sizeof(*kona_dev));
226 if (IS_ERR(host))
227 return PTR_ERR(host);
228
229 dev_dbg(dev, "%s: inited. IOADDR=%p\n", __func__, host->ioaddr);
230
231 pltfm_priv = sdhci_priv(host);
232
233 kona_dev = sdhci_pltfm_priv(pltfm_priv);
234 mutex_init(&kona_dev->write_lock);
235
236 ret = mmc_of_parse(host->mmc);
237 if (ret)
238 goto err_pltfm_free;
239
240 if (!host->mmc->f_max) {
241 dev_err(&pdev->dev, "Missing max-freq for SDHCI cfg\n");
242 ret = -ENXIO;
243 goto err_pltfm_free;
244 }
245
246 /* Get and enable the core clock */
247 pltfm_priv->clk = devm_clk_get(dev, NULL);
248 if (IS_ERR(pltfm_priv->clk)) {
249 dev_err(dev, "Failed to get core clock\n");
250 ret = PTR_ERR(pltfm_priv->clk);
251 goto err_pltfm_free;
252 }
253
254 ret = clk_set_rate(pltfm_priv->clk, host->mmc->f_max);
255 if (ret) {
256 dev_err(dev, "Failed to set rate core clock\n");
257 goto err_pltfm_free;
258 }
259
260 ret = clk_prepare_enable(pltfm_priv->clk);
261 if (ret) {
262 dev_err(dev, "Failed to enable core clock\n");
263 goto err_pltfm_free;
264 }
265
266 dev_dbg(dev, "non-removable=%c\n",
267 mmc_card_is_removable(host->mmc) ? 'N' : 'Y');
268 dev_dbg(dev, "cd_gpio %c, wp_gpio %c\n",
269 (mmc_gpio_get_cd(host->mmc) != -ENOSYS) ? 'Y' : 'N',
270 (mmc_gpio_get_ro(host->mmc) != -ENOSYS) ? 'Y' : 'N');
271
272 if (!mmc_card_is_removable(host->mmc))
273 host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
274
275 dev_dbg(dev, "is_8bit=%c\n",
276 (host->mmc->caps & MMC_CAP_8_BIT_DATA) ? 'Y' : 'N');
277
278 ret = sdhci_bcm_kona_sd_reset(host);
279 if (ret)
280 goto err_clk_disable;
281
282 sdhci_bcm_kona_sd_init(host);
283
284 ret = sdhci_add_host(host);
285 if (ret)
286 goto err_reset;
287
288 /* if device is eMMC, emulate card insert right here */
289 if (!mmc_card_is_removable(host->mmc)) {
290 ret = sdhci_bcm_kona_sd_card_emulate(host, 1);
291 if (ret) {
292 dev_err(dev,
293 "unable to emulate card insertion\n");
294 goto err_remove_host;
295 }
296 }
297 /*
298 * Since the card detection GPIO interrupt is configured to be
299 * edge sensitive, check the initial GPIO value here, emulate
300 * only if the card is present
301 */
302 if (mmc_gpio_get_cd(host->mmc) > 0)
303 sdhci_bcm_kona_sd_card_emulate(host, 1);
304
305 dev_dbg(dev, "initialized properly\n");
306 return 0;
307
308 err_remove_host:
309 sdhci_remove_host(host, 0);
310
311 err_reset:
312 sdhci_bcm_kona_sd_reset(host);
313
314 err_clk_disable:
315 clk_disable_unprepare(pltfm_priv->clk);
316
317 err_pltfm_free:
318 sdhci_pltfm_free(pdev);
319
320 dev_err(dev, "Probing of sdhci-pltfm failed: %d\n", ret);
321 return ret;
322 }
323
324 static struct platform_driver sdhci_bcm_kona_driver = {
325 .driver = {
326 .name = "sdhci-kona",
327 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
328 .pm = &sdhci_pltfm_pmops,
329 .of_match_table = sdhci_bcm_kona_of_match,
330 },
331 .probe = sdhci_bcm_kona_probe,
332 .remove = sdhci_pltfm_unregister,
333 };
334 module_platform_driver(sdhci_bcm_kona_driver);
335
336 MODULE_DESCRIPTION("SDHCI driver for Broadcom Kona platform");
337 MODULE_AUTHOR("Broadcom");
338 MODULE_LICENSE("GPL v2");
339