xref: /openbmc/linux/drivers/mmc/host/sdhci-iproc.c (revision 6491d698)
1 /*
2  * Copyright (C) 2014 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 /*
15  * iProc SDHCI platform driver
16  */
17 
18 #include <linux/acpi.h>
19 #include <linux/delay.h>
20 #include <linux/module.h>
21 #include <linux/mmc/host.h>
22 #include <linux/of.h>
23 #include <linux/of_device.h>
24 #include "sdhci-pltfm.h"
25 
26 struct sdhci_iproc_data {
27 	const struct sdhci_pltfm_data *pdata;
28 	u32 caps;
29 	u32 caps1;
30 	u32 mmc_caps;
31 };
32 
33 struct sdhci_iproc_host {
34 	const struct sdhci_iproc_data *data;
35 	u32 shadow_cmd;
36 	u32 shadow_blk;
37 	bool is_cmd_shadowed;
38 	bool is_blk_shadowed;
39 };
40 
41 #define REG_OFFSET_IN_BITS(reg) ((reg) << 3 & 0x18)
42 
43 static inline u32 sdhci_iproc_readl(struct sdhci_host *host, int reg)
44 {
45 	u32 val = readl(host->ioaddr + reg);
46 
47 	pr_debug("%s: readl [0x%02x] 0x%08x\n",
48 		 mmc_hostname(host->mmc), reg, val);
49 	return val;
50 }
51 
52 static u16 sdhci_iproc_readw(struct sdhci_host *host, int reg)
53 {
54 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
55 	struct sdhci_iproc_host *iproc_host = sdhci_pltfm_priv(pltfm_host);
56 	u32 val;
57 	u16 word;
58 
59 	if ((reg == SDHCI_TRANSFER_MODE) && iproc_host->is_cmd_shadowed) {
60 		/* Get the saved transfer mode */
61 		val = iproc_host->shadow_cmd;
62 	} else if ((reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) &&
63 		   iproc_host->is_blk_shadowed) {
64 		/* Get the saved block info */
65 		val = iproc_host->shadow_blk;
66 	} else {
67 		val = sdhci_iproc_readl(host, (reg & ~3));
68 	}
69 	word = val >> REG_OFFSET_IN_BITS(reg) & 0xffff;
70 	return word;
71 }
72 
73 static u8 sdhci_iproc_readb(struct sdhci_host *host, int reg)
74 {
75 	u32 val = sdhci_iproc_readl(host, (reg & ~3));
76 	u8 byte = val >> REG_OFFSET_IN_BITS(reg) & 0xff;
77 	return byte;
78 }
79 
80 static inline void sdhci_iproc_writel(struct sdhci_host *host, u32 val, int reg)
81 {
82 	pr_debug("%s: writel [0x%02x] 0x%08x\n",
83 		 mmc_hostname(host->mmc), reg, val);
84 
85 	writel(val, host->ioaddr + reg);
86 
87 	if (host->clock <= 400000) {
88 		/* Round up to micro-second four SD clock delay */
89 		if (host->clock)
90 			udelay((4 * 1000000 + host->clock - 1) / host->clock);
91 		else
92 			udelay(10);
93 	}
94 }
95 
96 /*
97  * The Arasan has a bugette whereby it may lose the content of successive
98  * writes to the same register that are within two SD-card clock cycles of
99  * each other (a clock domain crossing problem). The data
100  * register does not have this problem, which is just as well - otherwise we'd
101  * have to nobble the DMA engine too.
102  *
103  * This wouldn't be a problem with the code except that we can only write the
104  * controller with 32-bit writes.  So two different 16-bit registers are
105  * written back to back creates the problem.
106  *
107  * In reality, this only happens when SDHCI_BLOCK_SIZE and SDHCI_BLOCK_COUNT
108  * are written followed by SDHCI_TRANSFER_MODE and SDHCI_COMMAND.
109  * The BLOCK_SIZE and BLOCK_COUNT are meaningless until a command issued so
110  * the work around can be further optimized. We can keep shadow values of
111  * BLOCK_SIZE, BLOCK_COUNT, and TRANSFER_MODE until a COMMAND is issued.
112  * Then, write the BLOCK_SIZE+BLOCK_COUNT in a single 32-bit write followed
113  * by the TRANSFER+COMMAND in another 32-bit write.
114  */
115 static void sdhci_iproc_writew(struct sdhci_host *host, u16 val, int reg)
116 {
117 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
118 	struct sdhci_iproc_host *iproc_host = sdhci_pltfm_priv(pltfm_host);
119 	u32 word_shift = REG_OFFSET_IN_BITS(reg);
120 	u32 mask = 0xffff << word_shift;
121 	u32 oldval, newval;
122 
123 	if (reg == SDHCI_COMMAND) {
124 		/* Write the block now as we are issuing a command */
125 		if (iproc_host->is_blk_shadowed) {
126 			sdhci_iproc_writel(host, iproc_host->shadow_blk,
127 				SDHCI_BLOCK_SIZE);
128 			iproc_host->is_blk_shadowed = false;
129 		}
130 		oldval = iproc_host->shadow_cmd;
131 		iproc_host->is_cmd_shadowed = false;
132 	} else if ((reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) &&
133 		   iproc_host->is_blk_shadowed) {
134 		/* Block size and count are stored in shadow reg */
135 		oldval = iproc_host->shadow_blk;
136 	} else {
137 		/* Read reg, all other registers are not shadowed */
138 		oldval = sdhci_iproc_readl(host, (reg & ~3));
139 	}
140 	newval = (oldval & ~mask) | (val << word_shift);
141 
142 	if (reg == SDHCI_TRANSFER_MODE) {
143 		/* Save the transfer mode until the command is issued */
144 		iproc_host->shadow_cmd = newval;
145 		iproc_host->is_cmd_shadowed = true;
146 	} else if (reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) {
147 		/* Save the block info until the command is issued */
148 		iproc_host->shadow_blk = newval;
149 		iproc_host->is_blk_shadowed = true;
150 	} else {
151 		/* Command or other regular 32-bit write */
152 		sdhci_iproc_writel(host, newval, reg & ~3);
153 	}
154 }
155 
156 static void sdhci_iproc_writeb(struct sdhci_host *host, u8 val, int reg)
157 {
158 	u32 oldval = sdhci_iproc_readl(host, (reg & ~3));
159 	u32 byte_shift = REG_OFFSET_IN_BITS(reg);
160 	u32 mask = 0xff << byte_shift;
161 	u32 newval = (oldval & ~mask) | (val << byte_shift);
162 
163 	sdhci_iproc_writel(host, newval, reg & ~3);
164 }
165 
166 static unsigned int sdhci_iproc_get_max_clock(struct sdhci_host *host)
167 {
168 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
169 
170 	if (pltfm_host->clk)
171 		return sdhci_pltfm_clk_get_max_clock(host);
172 	else
173 		return pltfm_host->clock;
174 }
175 
176 static const struct sdhci_ops sdhci_iproc_ops = {
177 	.set_clock = sdhci_set_clock,
178 	.get_max_clock = sdhci_iproc_get_max_clock,
179 	.set_bus_width = sdhci_set_bus_width,
180 	.reset = sdhci_reset,
181 	.set_uhs_signaling = sdhci_set_uhs_signaling,
182 };
183 
184 static const struct sdhci_ops sdhci_iproc_32only_ops = {
185 	.read_l = sdhci_iproc_readl,
186 	.read_w = sdhci_iproc_readw,
187 	.read_b = sdhci_iproc_readb,
188 	.write_l = sdhci_iproc_writel,
189 	.write_w = sdhci_iproc_writew,
190 	.write_b = sdhci_iproc_writeb,
191 	.set_clock = sdhci_set_clock,
192 	.get_max_clock = sdhci_iproc_get_max_clock,
193 	.set_bus_width = sdhci_set_bus_width,
194 	.reset = sdhci_reset,
195 	.set_uhs_signaling = sdhci_set_uhs_signaling,
196 };
197 
198 static const struct sdhci_pltfm_data sdhci_iproc_cygnus_pltfm_data = {
199 	.quirks = SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK,
200 	.quirks2 = SDHCI_QUIRK2_ACMD23_BROKEN | SDHCI_QUIRK2_HOST_OFF_CARD_ON,
201 	.ops = &sdhci_iproc_32only_ops,
202 };
203 
204 static const struct sdhci_iproc_data iproc_cygnus_data = {
205 	.pdata = &sdhci_iproc_cygnus_pltfm_data,
206 	.caps = ((0x1 << SDHCI_MAX_BLOCK_SHIFT)
207 			& SDHCI_MAX_BLOCK_MASK) |
208 		SDHCI_CAN_VDD_330 |
209 		SDHCI_CAN_VDD_180 |
210 		SDHCI_CAN_DO_SUSPEND |
211 		SDHCI_CAN_DO_HISPD |
212 		SDHCI_CAN_DO_ADMA2 |
213 		SDHCI_CAN_DO_SDMA,
214 	.caps1 = SDHCI_DRIVER_TYPE_C |
215 		 SDHCI_DRIVER_TYPE_D |
216 		 SDHCI_SUPPORT_DDR50,
217 	.mmc_caps = MMC_CAP_1_8V_DDR,
218 };
219 
220 static const struct sdhci_pltfm_data sdhci_iproc_pltfm_data = {
221 	.quirks = SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
222 		  SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12,
223 	.quirks2 = SDHCI_QUIRK2_ACMD23_BROKEN,
224 	.ops = &sdhci_iproc_ops,
225 };
226 
227 static const struct sdhci_iproc_data iproc_data = {
228 	.pdata = &sdhci_iproc_pltfm_data,
229 	.caps = ((0x1 << SDHCI_MAX_BLOCK_SHIFT)
230 			& SDHCI_MAX_BLOCK_MASK) |
231 		SDHCI_CAN_VDD_330 |
232 		SDHCI_CAN_VDD_180 |
233 		SDHCI_CAN_DO_SUSPEND |
234 		SDHCI_CAN_DO_HISPD |
235 		SDHCI_CAN_DO_ADMA2 |
236 		SDHCI_CAN_DO_SDMA,
237 	.caps1 = SDHCI_DRIVER_TYPE_C |
238 		 SDHCI_DRIVER_TYPE_D |
239 		 SDHCI_SUPPORT_DDR50,
240 };
241 
242 static const struct sdhci_pltfm_data sdhci_bcm2835_pltfm_data = {
243 	.quirks = SDHCI_QUIRK_BROKEN_CARD_DETECTION |
244 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
245 		  SDHCI_QUIRK_MISSING_CAPS |
246 		  SDHCI_QUIRK_NO_HISPD_BIT,
247 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
248 	.ops = &sdhci_iproc_32only_ops,
249 };
250 
251 static const struct sdhci_iproc_data bcm2835_data = {
252 	.pdata = &sdhci_bcm2835_pltfm_data,
253 	.caps = ((0x1 << SDHCI_MAX_BLOCK_SHIFT)
254 			& SDHCI_MAX_BLOCK_MASK) |
255 		SDHCI_CAN_VDD_330 |
256 		SDHCI_CAN_DO_HISPD,
257 	.caps1 = SDHCI_DRIVER_TYPE_A |
258 		 SDHCI_DRIVER_TYPE_C,
259 	.mmc_caps = 0x00000000,
260 };
261 
262 static const struct of_device_id sdhci_iproc_of_match[] = {
263 	{ .compatible = "brcm,bcm2835-sdhci", .data = &bcm2835_data },
264 	{ .compatible = "brcm,sdhci-iproc-cygnus", .data = &iproc_cygnus_data},
265 	{ .compatible = "brcm,sdhci-iproc", .data = &iproc_data },
266 	{ }
267 };
268 MODULE_DEVICE_TABLE(of, sdhci_iproc_of_match);
269 
270 static const struct acpi_device_id sdhci_iproc_acpi_ids[] = {
271 	{ .id = "BRCM5871", .driver_data = (kernel_ulong_t)&iproc_cygnus_data },
272 	{ .id = "BRCM5872", .driver_data = (kernel_ulong_t)&iproc_data },
273 	{ /* sentinel */ }
274 };
275 MODULE_DEVICE_TABLE(acpi, sdhci_iproc_acpi_ids);
276 
277 static int sdhci_iproc_probe(struct platform_device *pdev)
278 {
279 	struct device *dev = &pdev->dev;
280 	const struct sdhci_iproc_data *iproc_data = NULL;
281 	struct sdhci_host *host;
282 	struct sdhci_iproc_host *iproc_host;
283 	struct sdhci_pltfm_host *pltfm_host;
284 	int ret;
285 
286 	iproc_data = device_get_match_data(dev);
287 	if (!iproc_data)
288 		return -ENODEV;
289 
290 	host = sdhci_pltfm_init(pdev, iproc_data->pdata, sizeof(*iproc_host));
291 	if (IS_ERR(host))
292 		return PTR_ERR(host);
293 
294 	pltfm_host = sdhci_priv(host);
295 	iproc_host = sdhci_pltfm_priv(pltfm_host);
296 
297 	iproc_host->data = iproc_data;
298 
299 	ret = mmc_of_parse(host->mmc);
300 	if (ret)
301 		goto err;
302 
303 	sdhci_get_property(pdev);
304 
305 	host->mmc->caps |= iproc_host->data->mmc_caps;
306 
307 	if (dev->of_node) {
308 		pltfm_host->clk = devm_clk_get(dev, NULL);
309 		if (IS_ERR(pltfm_host->clk)) {
310 			ret = PTR_ERR(pltfm_host->clk);
311 			goto err;
312 		}
313 		ret = clk_prepare_enable(pltfm_host->clk);
314 		if (ret) {
315 			dev_err(dev, "failed to enable host clk\n");
316 			goto err;
317 		}
318 	}
319 
320 	if (iproc_host->data->pdata->quirks & SDHCI_QUIRK_MISSING_CAPS) {
321 		host->caps = iproc_host->data->caps;
322 		host->caps1 = iproc_host->data->caps1;
323 	}
324 
325 	ret = sdhci_add_host(host);
326 	if (ret)
327 		goto err_clk;
328 
329 	return 0;
330 
331 err_clk:
332 	if (dev->of_node)
333 		clk_disable_unprepare(pltfm_host->clk);
334 err:
335 	sdhci_pltfm_free(pdev);
336 	return ret;
337 }
338 
339 static struct platform_driver sdhci_iproc_driver = {
340 	.driver = {
341 		.name = "sdhci-iproc",
342 		.of_match_table = sdhci_iproc_of_match,
343 		.acpi_match_table = ACPI_PTR(sdhci_iproc_acpi_ids),
344 		.pm = &sdhci_pltfm_pmops,
345 	},
346 	.probe = sdhci_iproc_probe,
347 	.remove = sdhci_pltfm_unregister,
348 };
349 module_platform_driver(sdhci_iproc_driver);
350 
351 MODULE_AUTHOR("Broadcom");
352 MODULE_DESCRIPTION("IPROC SDHCI driver");
353 MODULE_LICENSE("GPL v2");
354