xref: /openbmc/linux/drivers/mmc/host/sdhci_am654.c (revision 74a22e8f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * sdhci_am654.c - SDHCI driver for TI's AM654 SOCs
4  *
5  * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com
6  *
7  */
8 #include <linux/clk.h>
9 #include <linux/module.h>
10 #include <linux/pm_runtime.h>
11 #include <linux/property.h>
12 #include <linux/regmap.h>
13 
14 #include "sdhci-pltfm.h"
15 
16 /* CTL_CFG Registers */
17 #define CTL_CFG_2		0x14
18 
19 #define SLOTTYPE_MASK		GENMASK(31, 30)
20 #define SLOTTYPE_EMBEDDED	BIT(30)
21 
22 /* PHY Registers */
23 #define PHY_CTRL1	0x100
24 #define PHY_CTRL2	0x104
25 #define PHY_CTRL3	0x108
26 #define PHY_CTRL4	0x10C
27 #define PHY_CTRL5	0x110
28 #define PHY_CTRL6	0x114
29 #define PHY_STAT1	0x130
30 #define PHY_STAT2	0x134
31 
32 #define IOMUX_ENABLE_SHIFT	31
33 #define IOMUX_ENABLE_MASK	BIT(IOMUX_ENABLE_SHIFT)
34 #define OTAPDLYENA_SHIFT	20
35 #define OTAPDLYENA_MASK		BIT(OTAPDLYENA_SHIFT)
36 #define OTAPDLYSEL_SHIFT	12
37 #define OTAPDLYSEL_MASK		GENMASK(15, 12)
38 #define STRBSEL_SHIFT		24
39 #define STRBSEL_MASK		GENMASK(27, 24)
40 #define SEL50_SHIFT		8
41 #define SEL50_MASK		BIT(SEL50_SHIFT)
42 #define SEL100_SHIFT		9
43 #define SEL100_MASK		BIT(SEL100_SHIFT)
44 #define DLL_TRIM_ICP_SHIFT	4
45 #define DLL_TRIM_ICP_MASK	GENMASK(7, 4)
46 #define DR_TY_SHIFT		20
47 #define DR_TY_MASK		GENMASK(22, 20)
48 #define ENDLL_SHIFT		1
49 #define ENDLL_MASK		BIT(ENDLL_SHIFT)
50 #define DLLRDY_SHIFT		0
51 #define DLLRDY_MASK		BIT(DLLRDY_SHIFT)
52 #define PDB_SHIFT		0
53 #define PDB_MASK		BIT(PDB_SHIFT)
54 #define CALDONE_SHIFT		1
55 #define CALDONE_MASK		BIT(CALDONE_SHIFT)
56 #define RETRIM_SHIFT		17
57 #define RETRIM_MASK		BIT(RETRIM_SHIFT)
58 
59 #define DRIVER_STRENGTH_50_OHM	0x0
60 #define DRIVER_STRENGTH_33_OHM	0x1
61 #define DRIVER_STRENGTH_66_OHM	0x2
62 #define DRIVER_STRENGTH_100_OHM	0x3
63 #define DRIVER_STRENGTH_40_OHM	0x4
64 
65 #define CLOCK_TOO_SLOW_HZ	400000
66 
67 static struct regmap_config sdhci_am654_regmap_config = {
68 	.reg_bits = 32,
69 	.val_bits = 32,
70 	.reg_stride = 4,
71 	.fast_io = true,
72 };
73 
74 struct sdhci_am654_data {
75 	struct regmap *base;
76 	int otap_del_sel;
77 	int trm_icp;
78 	int drv_strength;
79 	bool dll_on;
80 };
81 
82 static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
83 {
84 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
85 	struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
86 	int sel50, sel100;
87 	u32 mask, val;
88 	int ret;
89 
90 	if (sdhci_am654->dll_on) {
91 		regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
92 				   ENDLL_MASK, 0);
93 
94 		sdhci_am654->dll_on = false;
95 	}
96 
97 	sdhci_set_clock(host, clock);
98 
99 	if (clock > CLOCK_TOO_SLOW_HZ) {
100 		/* Setup DLL Output TAP delay */
101 		mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
102 		val = (1 << OTAPDLYENA_SHIFT) |
103 		      (sdhci_am654->otap_del_sel << OTAPDLYSEL_SHIFT);
104 		regmap_update_bits(sdhci_am654->base, PHY_CTRL4,
105 				   mask, val);
106 		switch (clock) {
107 		case 200000000:
108 			sel50 = 0;
109 			sel100 = 0;
110 			break;
111 		case 100000000:
112 			sel50 = 0;
113 			sel100 = 1;
114 			break;
115 		default:
116 			sel50 = 1;
117 			sel100 = 0;
118 		}
119 
120 		/* Configure PHY DLL frequency */
121 		mask = SEL50_MASK | SEL100_MASK;
122 		val = (sel50 << SEL50_SHIFT) | (sel100 << SEL100_SHIFT);
123 		regmap_update_bits(sdhci_am654->base, PHY_CTRL5,
124 				   mask, val);
125 		/* Configure DLL TRIM */
126 		mask = DLL_TRIM_ICP_MASK;
127 		val = sdhci_am654->trm_icp << DLL_TRIM_ICP_SHIFT;
128 
129 		/* Configure DLL driver strength */
130 		mask |= DR_TY_MASK;
131 		val |= sdhci_am654->drv_strength << DR_TY_SHIFT;
132 		regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
133 				   mask, val);
134 		/* Enable DLL */
135 		regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
136 				   ENDLL_MASK, 0x1 << ENDLL_SHIFT);
137 		/*
138 		 * Poll for DLL ready. Use a one second timeout.
139 		 * Works in all experiments done so far
140 		 */
141 		ret = regmap_read_poll_timeout(sdhci_am654->base,
142 					 PHY_STAT1, val,
143 					 val & DLLRDY_MASK,
144 					 1000, 1000000);
145 
146 		sdhci_am654->dll_on = true;
147 	}
148 }
149 
150 static void sdhci_am654_set_power(struct sdhci_host *host, unsigned char mode,
151 				  unsigned short vdd)
152 {
153 	if (!IS_ERR(host->mmc->supply.vmmc)) {
154 		struct mmc_host *mmc = host->mmc;
155 
156 		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
157 	}
158 	sdhci_set_power_noreg(host, mode, vdd);
159 }
160 
161 static void sdhci_am654_write_b(struct sdhci_host *host, u8 val, int reg)
162 {
163 	unsigned char timing = host->mmc->ios.timing;
164 
165 	if (reg == SDHCI_HOST_CONTROL) {
166 		switch (timing) {
167 		/*
168 		 * According to the data manual, HISPD bit
169 		 * should not be set in these speed modes.
170 		 */
171 		case MMC_TIMING_SD_HS:
172 		case MMC_TIMING_MMC_HS:
173 		case MMC_TIMING_UHS_SDR12:
174 		case MMC_TIMING_UHS_SDR25:
175 			val &= ~SDHCI_CTRL_HISPD;
176 		}
177 	}
178 
179 	writeb(val, host->ioaddr + reg);
180 }
181 
182 static struct sdhci_ops sdhci_am654_ops = {
183 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
184 	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
185 	.set_uhs_signaling = sdhci_set_uhs_signaling,
186 	.set_bus_width = sdhci_set_bus_width,
187 	.set_power = sdhci_am654_set_power,
188 	.set_clock = sdhci_am654_set_clock,
189 	.write_b = sdhci_am654_write_b,
190 	.reset = sdhci_reset,
191 };
192 
193 static const struct sdhci_pltfm_data sdhci_am654_pdata = {
194 	.ops = &sdhci_am654_ops,
195 	.quirks = SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
196 		  SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12,
197 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
198 };
199 
200 static int sdhci_am654_init(struct sdhci_host *host)
201 {
202 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
203 	struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
204 	u32 ctl_cfg_2 = 0;
205 	u32 mask;
206 	u32 val;
207 	int ret;
208 
209 	/* Reset OTAP to default value */
210 	mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
211 	regmap_update_bits(sdhci_am654->base, PHY_CTRL4,
212 				   mask, 0x0);
213 
214 	regmap_read(sdhci_am654->base, PHY_STAT1, &val);
215 	if (~val & CALDONE_MASK) {
216 		/* Calibrate IO lines */
217 		regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
218 				   PDB_MASK, PDB_MASK);
219 		ret = regmap_read_poll_timeout(sdhci_am654->base, PHY_STAT1,
220 					       val, val & CALDONE_MASK, 1, 20);
221 		if (ret)
222 			return ret;
223 	}
224 
225 	/* Enable pins by setting IO mux to 0 */
226 	regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
227 			   IOMUX_ENABLE_MASK, 0);
228 
229 	/* Set slot type based on SD or eMMC */
230 	if (host->mmc->caps & MMC_CAP_NONREMOVABLE)
231 		ctl_cfg_2 = SLOTTYPE_EMBEDDED;
232 
233 	regmap_update_bits(sdhci_am654->base, CTL_CFG_2,
234 			   ctl_cfg_2, SLOTTYPE_MASK);
235 
236 	return sdhci_add_host(host);
237 }
238 
239 static int sdhci_am654_get_of_property(struct platform_device *pdev,
240 					struct sdhci_am654_data *sdhci_am654)
241 {
242 	struct device *dev = &pdev->dev;
243 	int drv_strength;
244 	int ret;
245 
246 	ret = device_property_read_u32(dev, "ti,trm-icp",
247 				       &sdhci_am654->trm_icp);
248 	if (ret)
249 		return ret;
250 
251 	ret = device_property_read_u32(dev, "ti,otap-del-sel",
252 				       &sdhci_am654->otap_del_sel);
253 	if (ret)
254 		return ret;
255 
256 	ret = device_property_read_u32(dev, "ti,driver-strength-ohm",
257 				       &drv_strength);
258 	if (ret)
259 		return ret;
260 
261 	switch (drv_strength) {
262 	case 50:
263 		sdhci_am654->drv_strength = DRIVER_STRENGTH_50_OHM;
264 		break;
265 	case 33:
266 		sdhci_am654->drv_strength = DRIVER_STRENGTH_33_OHM;
267 		break;
268 	case 66:
269 		sdhci_am654->drv_strength = DRIVER_STRENGTH_66_OHM;
270 		break;
271 	case 100:
272 		sdhci_am654->drv_strength = DRIVER_STRENGTH_100_OHM;
273 		break;
274 	case 40:
275 		sdhci_am654->drv_strength = DRIVER_STRENGTH_40_OHM;
276 		break;
277 	default:
278 		dev_err(dev, "Invalid driver strength\n");
279 		return -EINVAL;
280 	}
281 
282 	sdhci_get_of_property(pdev);
283 
284 	return 0;
285 }
286 
287 static int sdhci_am654_probe(struct platform_device *pdev)
288 {
289 	struct sdhci_pltfm_host *pltfm_host;
290 	struct sdhci_am654_data *sdhci_am654;
291 	struct sdhci_host *host;
292 	struct resource *res;
293 	struct clk *clk_xin;
294 	struct device *dev = &pdev->dev;
295 	void __iomem *base;
296 	int ret;
297 
298 	host = sdhci_pltfm_init(pdev, &sdhci_am654_pdata, sizeof(*sdhci_am654));
299 	if (IS_ERR(host))
300 		return PTR_ERR(host);
301 
302 	pltfm_host = sdhci_priv(host);
303 	sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
304 
305 	clk_xin = devm_clk_get(dev, "clk_xin");
306 	if (IS_ERR(clk_xin)) {
307 		dev_err(dev, "clk_xin clock not found.\n");
308 		ret = PTR_ERR(clk_xin);
309 		goto err_pltfm_free;
310 	}
311 
312 	pltfm_host->clk = clk_xin;
313 
314 	/* Clocks are enabled using pm_runtime */
315 	pm_runtime_enable(dev);
316 	ret = pm_runtime_get_sync(dev);
317 	if (ret < 0) {
318 		pm_runtime_put_noidle(dev);
319 		goto pm_runtime_disable;
320 	}
321 
322 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
323 	base = devm_ioremap_resource(dev, res);
324 	if (IS_ERR(base)) {
325 		ret = PTR_ERR(base);
326 		goto pm_runtime_put;
327 	}
328 
329 	sdhci_am654->base = devm_regmap_init_mmio(dev, base,
330 						  &sdhci_am654_regmap_config);
331 	if (IS_ERR(sdhci_am654->base)) {
332 		dev_err(dev, "Failed to initialize regmap\n");
333 		ret = PTR_ERR(sdhci_am654->base);
334 		goto pm_runtime_put;
335 	}
336 
337 	ret = sdhci_am654_get_of_property(pdev, sdhci_am654);
338 	if (ret)
339 		goto pm_runtime_put;
340 
341 	ret = mmc_of_parse(host->mmc);
342 	if (ret) {
343 		dev_err(dev, "parsing dt failed (%d)\n", ret);
344 		goto pm_runtime_put;
345 	}
346 
347 	ret = sdhci_am654_init(host);
348 	if (ret)
349 		goto pm_runtime_put;
350 
351 	return 0;
352 
353 pm_runtime_put:
354 	pm_runtime_put_sync(dev);
355 pm_runtime_disable:
356 	pm_runtime_disable(dev);
357 err_pltfm_free:
358 	sdhci_pltfm_free(pdev);
359 	return ret;
360 }
361 
362 static int sdhci_am654_remove(struct platform_device *pdev)
363 {
364 	struct sdhci_host *host = platform_get_drvdata(pdev);
365 	int ret;
366 
367 	sdhci_remove_host(host, true);
368 	ret = pm_runtime_put_sync(&pdev->dev);
369 	if (ret < 0)
370 		return ret;
371 
372 	pm_runtime_disable(&pdev->dev);
373 	sdhci_pltfm_free(pdev);
374 
375 	return 0;
376 }
377 
378 static const struct of_device_id sdhci_am654_of_match[] = {
379 	{ .compatible = "ti,am654-sdhci-5.1" },
380 	{ /* sentinel */ }
381 };
382 
383 static struct platform_driver sdhci_am654_driver = {
384 	.driver = {
385 		.name = "sdhci-am654",
386 		.of_match_table = sdhci_am654_of_match,
387 	},
388 	.probe = sdhci_am654_probe,
389 	.remove = sdhci_am654_remove,
390 };
391 
392 module_platform_driver(sdhci_am654_driver);
393 
394 MODULE_DESCRIPTION("Driver for SDHCI Controller on TI's AM654 devices");
395 MODULE_AUTHOR("Faiz Abbas <faiz_abbas@ti.com>");
396 MODULE_LICENSE("GPL");
397