xref: /openbmc/linux/drivers/mmc/host/sdhci-brcmstb.c (revision ba007062)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * sdhci-brcmstb.c Support for SDHCI on Broadcom BRCMSTB SoC's
4  *
5  * Copyright (C) 2015 Broadcom Corporation
6  */
7 
8 #include <linux/io.h>
9 #include <linux/mmc/host.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/bitops.h>
13 #include <linux/delay.h>
14 
15 #include "sdhci-pltfm.h"
16 #include "cqhci.h"
17 
18 #define SDHCI_VENDOR 0x78
19 #define  SDHCI_VENDOR_ENHANCED_STRB 0x1
20 #define  SDHCI_VENDOR_GATE_SDCLK_EN 0x2
21 
22 #define BRCMSTB_MATCH_FLAGS_NO_64BIT		BIT(0)
23 #define BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT	BIT(1)
24 #define BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE	BIT(2)
25 
26 #define BRCMSTB_PRIV_FLAGS_HAS_CQE		BIT(0)
27 #define BRCMSTB_PRIV_FLAGS_GATE_CLOCK		BIT(1)
28 
29 #define SDHCI_ARASAN_CQE_BASE_ADDR		0x200
30 
31 struct sdhci_brcmstb_priv {
32 	void __iomem *cfg_regs;
33 	unsigned int flags;
34 	struct clk *base_clk;
35 	u32 base_freq_hz;
36 };
37 
38 struct brcmstb_match_priv {
39 	void (*hs400es)(struct mmc_host *mmc, struct mmc_ios *ios);
40 	struct sdhci_ops *ops;
41 	const unsigned int flags;
42 };
43 
44 static inline void enable_clock_gating(struct sdhci_host *host)
45 {
46 	u32 reg;
47 
48 	reg = sdhci_readl(host, SDHCI_VENDOR);
49 	reg |= SDHCI_VENDOR_GATE_SDCLK_EN;
50 	sdhci_writel(host, reg, SDHCI_VENDOR);
51 }
52 
53 static void brcmstb_reset(struct sdhci_host *host, u8 mask)
54 {
55 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
56 	struct sdhci_brcmstb_priv *priv = sdhci_pltfm_priv(pltfm_host);
57 
58 	sdhci_reset(host, mask);
59 
60 	/* Reset will clear this, so re-enable it */
61 	if (priv->flags & BRCMSTB_PRIV_FLAGS_GATE_CLOCK)
62 		enable_clock_gating(host);
63 }
64 
65 static void sdhci_brcmstb_hs400es(struct mmc_host *mmc, struct mmc_ios *ios)
66 {
67 	struct sdhci_host *host = mmc_priv(mmc);
68 
69 	u32 reg;
70 
71 	dev_dbg(mmc_dev(mmc), "%s(): Setting HS400-Enhanced-Strobe mode\n",
72 		__func__);
73 	reg = readl(host->ioaddr + SDHCI_VENDOR);
74 	if (ios->enhanced_strobe)
75 		reg |= SDHCI_VENDOR_ENHANCED_STRB;
76 	else
77 		reg &= ~SDHCI_VENDOR_ENHANCED_STRB;
78 	writel(reg, host->ioaddr + SDHCI_VENDOR);
79 }
80 
81 static void sdhci_brcmstb_set_clock(struct sdhci_host *host, unsigned int clock)
82 {
83 	u16 clk;
84 
85 	host->mmc->actual_clock = 0;
86 
87 	clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock);
88 	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
89 
90 	if (clock == 0)
91 		return;
92 
93 	sdhci_enable_clk(host, clk);
94 }
95 
96 static void sdhci_brcmstb_set_uhs_signaling(struct sdhci_host *host,
97 					    unsigned int timing)
98 {
99 	u16 ctrl_2;
100 
101 	dev_dbg(mmc_dev(host->mmc), "%s: Setting UHS signaling for %d timing\n",
102 		__func__, timing);
103 	ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
104 	/* Select Bus Speed Mode for host */
105 	ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
106 	if ((timing == MMC_TIMING_MMC_HS200) ||
107 	    (timing == MMC_TIMING_UHS_SDR104))
108 		ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
109 	else if (timing == MMC_TIMING_UHS_SDR12)
110 		ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
111 	else if (timing == MMC_TIMING_SD_HS ||
112 		 timing == MMC_TIMING_MMC_HS ||
113 		 timing == MMC_TIMING_UHS_SDR25)
114 		ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
115 	else if (timing == MMC_TIMING_UHS_SDR50)
116 		ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
117 	else if ((timing == MMC_TIMING_UHS_DDR50) ||
118 		 (timing == MMC_TIMING_MMC_DDR52))
119 		ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
120 	else if (timing == MMC_TIMING_MMC_HS400)
121 		ctrl_2 |= SDHCI_CTRL_HS400; /* Non-standard */
122 	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
123 }
124 
125 static void sdhci_brcmstb_dumpregs(struct mmc_host *mmc)
126 {
127 	sdhci_dumpregs(mmc_priv(mmc));
128 }
129 
130 static void sdhci_brcmstb_cqe_enable(struct mmc_host *mmc)
131 {
132 	struct sdhci_host *host = mmc_priv(mmc);
133 	u32 reg;
134 
135 	reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
136 	while (reg & SDHCI_DATA_AVAILABLE) {
137 		sdhci_readl(host, SDHCI_BUFFER);
138 		reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
139 	}
140 
141 	sdhci_cqe_enable(mmc);
142 }
143 
144 static const struct cqhci_host_ops sdhci_brcmstb_cqhci_ops = {
145 	.enable         = sdhci_brcmstb_cqe_enable,
146 	.disable        = sdhci_cqe_disable,
147 	.dumpregs       = sdhci_brcmstb_dumpregs,
148 };
149 
150 static struct sdhci_ops sdhci_brcmstb_ops = {
151 	.set_clock = sdhci_set_clock,
152 	.set_bus_width = sdhci_set_bus_width,
153 	.reset = sdhci_reset,
154 	.set_uhs_signaling = sdhci_set_uhs_signaling,
155 };
156 
157 static struct sdhci_ops sdhci_brcmstb_ops_7216 = {
158 	.set_clock = sdhci_brcmstb_set_clock,
159 	.set_bus_width = sdhci_set_bus_width,
160 	.reset = brcmstb_reset,
161 	.set_uhs_signaling = sdhci_brcmstb_set_uhs_signaling,
162 };
163 
164 static struct brcmstb_match_priv match_priv_7425 = {
165 	.flags = BRCMSTB_MATCH_FLAGS_NO_64BIT |
166 	BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT,
167 	.ops = &sdhci_brcmstb_ops,
168 };
169 
170 static struct brcmstb_match_priv match_priv_7445 = {
171 	.flags = BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT,
172 	.ops = &sdhci_brcmstb_ops,
173 };
174 
175 static const struct brcmstb_match_priv match_priv_7216 = {
176 	.flags = BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE,
177 	.hs400es = sdhci_brcmstb_hs400es,
178 	.ops = &sdhci_brcmstb_ops_7216,
179 };
180 
181 static const struct of_device_id sdhci_brcm_of_match[] = {
182 	{ .compatible = "brcm,bcm7425-sdhci", .data = &match_priv_7425 },
183 	{ .compatible = "brcm,bcm7445-sdhci", .data = &match_priv_7445 },
184 	{ .compatible = "brcm,bcm7216-sdhci", .data = &match_priv_7216 },
185 	{},
186 };
187 
188 static u32 sdhci_brcmstb_cqhci_irq(struct sdhci_host *host, u32 intmask)
189 {
190 	int cmd_error = 0;
191 	int data_error = 0;
192 
193 	if (!sdhci_cqe_irq(host, intmask, &cmd_error, &data_error))
194 		return intmask;
195 
196 	cqhci_irq(host->mmc, intmask, cmd_error, data_error);
197 
198 	return 0;
199 }
200 
201 static int sdhci_brcmstb_add_host(struct sdhci_host *host,
202 				  struct sdhci_brcmstb_priv *priv)
203 {
204 	struct cqhci_host *cq_host;
205 	bool dma64;
206 	int ret;
207 
208 	if ((priv->flags & BRCMSTB_PRIV_FLAGS_HAS_CQE) == 0)
209 		return sdhci_add_host(host);
210 
211 	dev_dbg(mmc_dev(host->mmc), "CQE is enabled\n");
212 	host->mmc->caps2 |= MMC_CAP2_CQE | MMC_CAP2_CQE_DCMD;
213 	ret = sdhci_setup_host(host);
214 	if (ret)
215 		return ret;
216 
217 	cq_host = devm_kzalloc(mmc_dev(host->mmc),
218 			       sizeof(*cq_host), GFP_KERNEL);
219 	if (!cq_host) {
220 		ret = -ENOMEM;
221 		goto cleanup;
222 	}
223 
224 	cq_host->mmio = host->ioaddr + SDHCI_ARASAN_CQE_BASE_ADDR;
225 	cq_host->ops = &sdhci_brcmstb_cqhci_ops;
226 
227 	dma64 = host->flags & SDHCI_USE_64_BIT_DMA;
228 	if (dma64) {
229 		dev_dbg(mmc_dev(host->mmc), "Using 64 bit DMA\n");
230 		cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
231 	}
232 
233 	ret = cqhci_init(cq_host, host->mmc, dma64);
234 	if (ret)
235 		goto cleanup;
236 
237 	ret = __sdhci_add_host(host);
238 	if (ret)
239 		goto cleanup;
240 
241 	return 0;
242 
243 cleanup:
244 	sdhci_cleanup_host(host);
245 	return ret;
246 }
247 
248 static int sdhci_brcmstb_probe(struct platform_device *pdev)
249 {
250 	const struct brcmstb_match_priv *match_priv;
251 	struct sdhci_pltfm_data brcmstb_pdata;
252 	struct sdhci_pltfm_host *pltfm_host;
253 	const struct of_device_id *match;
254 	struct sdhci_brcmstb_priv *priv;
255 	u32 actual_clock_mhz;
256 	struct sdhci_host *host;
257 	struct resource *iomem;
258 	struct clk *clk;
259 	struct clk *base_clk = NULL;
260 	int res;
261 
262 	match = of_match_node(sdhci_brcm_of_match, pdev->dev.of_node);
263 	match_priv = match->data;
264 
265 	dev_dbg(&pdev->dev, "Probe found match for %s\n",  match->compatible);
266 
267 	clk = devm_clk_get_optional(&pdev->dev, NULL);
268 	if (IS_ERR(clk))
269 		return dev_err_probe(&pdev->dev, PTR_ERR(clk),
270 				     "Failed to get clock from Device Tree\n");
271 
272 	res = clk_prepare_enable(clk);
273 	if (res)
274 		return res;
275 
276 	memset(&brcmstb_pdata, 0, sizeof(brcmstb_pdata));
277 	brcmstb_pdata.ops = match_priv->ops;
278 	host = sdhci_pltfm_init(pdev, &brcmstb_pdata,
279 				sizeof(struct sdhci_brcmstb_priv));
280 	if (IS_ERR(host)) {
281 		res = PTR_ERR(host);
282 		goto err_clk;
283 	}
284 
285 	pltfm_host = sdhci_priv(host);
286 	priv = sdhci_pltfm_priv(pltfm_host);
287 	if (device_property_read_bool(&pdev->dev, "supports-cqe")) {
288 		priv->flags |= BRCMSTB_PRIV_FLAGS_HAS_CQE;
289 		match_priv->ops->irq = sdhci_brcmstb_cqhci_irq;
290 	}
291 
292 	/* Map in the non-standard CFG registers */
293 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
294 	priv->cfg_regs = devm_ioremap_resource(&pdev->dev, iomem);
295 	if (IS_ERR(priv->cfg_regs)) {
296 		res = PTR_ERR(priv->cfg_regs);
297 		goto err;
298 	}
299 
300 	sdhci_get_of_property(pdev);
301 	res = mmc_of_parse(host->mmc);
302 	if (res)
303 		goto err;
304 
305 	/*
306 	 * Automatic clock gating does not work for SD cards that may
307 	 * voltage switch so only enable it for non-removable devices.
308 	 */
309 	if ((match_priv->flags & BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE) &&
310 	    (host->mmc->caps & MMC_CAP_NONREMOVABLE))
311 		priv->flags |= BRCMSTB_PRIV_FLAGS_GATE_CLOCK;
312 
313 	/*
314 	 * If the chip has enhanced strobe and it's enabled, add
315 	 * callback
316 	 */
317 	if (match_priv->hs400es &&
318 	    (host->mmc->caps2 & MMC_CAP2_HS400_ES))
319 		host->mmc_host_ops.hs400_enhanced_strobe = match_priv->hs400es;
320 
321 	/*
322 	 * Supply the existing CAPS, but clear the UHS modes. This
323 	 * will allow these modes to be specified by device tree
324 	 * properties through mmc_of_parse().
325 	 */
326 	host->caps = sdhci_readl(host, SDHCI_CAPABILITIES);
327 	if (match_priv->flags & BRCMSTB_MATCH_FLAGS_NO_64BIT)
328 		host->caps &= ~SDHCI_CAN_64BIT;
329 	host->caps1 = sdhci_readl(host, SDHCI_CAPABILITIES_1);
330 	host->caps1 &= ~(SDHCI_SUPPORT_SDR50 | SDHCI_SUPPORT_SDR104 |
331 			 SDHCI_SUPPORT_DDR50);
332 	host->quirks |= SDHCI_QUIRK_MISSING_CAPS;
333 
334 	if (match_priv->flags & BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT)
335 		host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;
336 
337 	/* Change the base clock frequency if the DT property exists */
338 	if (device_property_read_u32(&pdev->dev, "clock-frequency",
339 				     &priv->base_freq_hz) != 0)
340 		goto add_host;
341 
342 	base_clk = devm_clk_get_optional(&pdev->dev, "sdio_freq");
343 	if (IS_ERR(base_clk)) {
344 		dev_warn(&pdev->dev, "Clock for \"sdio_freq\" not found\n");
345 		goto add_host;
346 	}
347 
348 	res = clk_prepare_enable(base_clk);
349 	if (res)
350 		goto err;
351 
352 	/* set improved clock rate */
353 	clk_set_rate(base_clk, priv->base_freq_hz);
354 	actual_clock_mhz = clk_get_rate(base_clk) / 1000000;
355 
356 	host->caps &= ~SDHCI_CLOCK_V3_BASE_MASK;
357 	host->caps |= (actual_clock_mhz << SDHCI_CLOCK_BASE_SHIFT);
358 	/* Disable presets because they are now incorrect */
359 	host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
360 
361 	dev_dbg(&pdev->dev, "Base Clock Frequency changed to %dMHz\n",
362 		actual_clock_mhz);
363 	priv->base_clk = base_clk;
364 
365 add_host:
366 	res = sdhci_brcmstb_add_host(host, priv);
367 	if (res)
368 		goto err;
369 
370 	pltfm_host->clk = clk;
371 	return res;
372 
373 err:
374 	sdhci_pltfm_free(pdev);
375 err_clk:
376 	clk_disable_unprepare(base_clk);
377 	clk_disable_unprepare(clk);
378 	return res;
379 }
380 
381 static void sdhci_brcmstb_shutdown(struct platform_device *pdev)
382 {
383 	sdhci_pltfm_suspend(&pdev->dev);
384 }
385 
386 MODULE_DEVICE_TABLE(of, sdhci_brcm_of_match);
387 
388 #ifdef CONFIG_PM_SLEEP
389 static int sdhci_brcmstb_suspend(struct device *dev)
390 {
391 	struct sdhci_host *host = dev_get_drvdata(dev);
392 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
393 	struct sdhci_brcmstb_priv *priv = sdhci_pltfm_priv(pltfm_host);
394 
395 	clk_disable_unprepare(priv->base_clk);
396 	return sdhci_pltfm_suspend(dev);
397 }
398 
399 static int sdhci_brcmstb_resume(struct device *dev)
400 {
401 	struct sdhci_host *host = dev_get_drvdata(dev);
402 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
403 	struct sdhci_brcmstb_priv *priv = sdhci_pltfm_priv(pltfm_host);
404 	int ret;
405 
406 	ret = sdhci_pltfm_resume(dev);
407 	if (!ret && priv->base_freq_hz) {
408 		ret = clk_prepare_enable(priv->base_clk);
409 		/*
410 		 * Note: using clk_get_rate() below as clk_get_rate()
411 		 * honors CLK_GET_RATE_NOCACHE attribute, but clk_set_rate()
412 		 * may do implicit get_rate() calls that do not honor
413 		 * CLK_GET_RATE_NOCACHE.
414 		 */
415 		if (!ret &&
416 		    (clk_get_rate(priv->base_clk) != priv->base_freq_hz))
417 			ret = clk_set_rate(priv->base_clk, priv->base_freq_hz);
418 	}
419 
420 	return ret;
421 }
422 #endif
423 
424 static const struct dev_pm_ops sdhci_brcmstb_pmops = {
425 	SET_SYSTEM_SLEEP_PM_OPS(sdhci_brcmstb_suspend, sdhci_brcmstb_resume)
426 };
427 
428 static struct platform_driver sdhci_brcmstb_driver = {
429 	.driver		= {
430 		.name	= "sdhci-brcmstb",
431 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
432 		.pm	= &sdhci_brcmstb_pmops,
433 		.of_match_table = of_match_ptr(sdhci_brcm_of_match),
434 	},
435 	.probe		= sdhci_brcmstb_probe,
436 	.remove		= sdhci_pltfm_unregister,
437 	.shutdown	= sdhci_brcmstb_shutdown,
438 };
439 
440 module_platform_driver(sdhci_brcmstb_driver);
441 
442 MODULE_DESCRIPTION("SDHCI driver for Broadcom BRCMSTB SoCs");
443 MODULE_AUTHOR("Broadcom");
444 MODULE_LICENSE("GPL v2");
445