xref: /linux/drivers/mmc/host/meson-mx-sdio.c (revision 7bb377107c72a40ab7505341f8626c8eb79a0cb7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * meson-mx-sdio.c - Meson6, Meson8 and Meson8b SDIO/MMC Host Controller
4  *
5  * Copyright (C) 2015 Endless Mobile, Inc.
6  * Author: Carlo Caione <carlo@endlessm.com>
7  * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/clk.h>
12 #include <linux/clk-provider.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/module.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/ioport.h>
20 #include <linux/platform_device.h>
21 #include <linux/of_platform.h>
22 #include <linux/timer.h>
23 #include <linux/types.h>
24 
25 #include <linux/mmc/host.h>
26 #include <linux/mmc/mmc.h>
27 #include <linux/mmc/sdio.h>
28 #include <linux/mmc/slot-gpio.h>
29 
30 #define MESON_MX_SDIO_ARGU					0x00
31 
32 #define MESON_MX_SDIO_SEND					0x04
33 	#define MESON_MX_SDIO_SEND_COMMAND_INDEX_MASK		GENMASK(7, 0)
34 	#define MESON_MX_SDIO_SEND_CMD_RESP_BITS_MASK		GENMASK(15, 8)
35 	#define MESON_MX_SDIO_SEND_RESP_WITHOUT_CRC7		BIT(16)
36 	#define MESON_MX_SDIO_SEND_RESP_HAS_DATA		BIT(17)
37 	#define MESON_MX_SDIO_SEND_RESP_CRC7_FROM_8		BIT(18)
38 	#define MESON_MX_SDIO_SEND_CHECK_DAT0_BUSY		BIT(19)
39 	#define MESON_MX_SDIO_SEND_DATA				BIT(20)
40 	#define MESON_MX_SDIO_SEND_USE_INT_WINDOW		BIT(21)
41 	#define MESON_MX_SDIO_SEND_REPEAT_PACKAGE_TIMES_MASK	GENMASK(31, 24)
42 
43 #define MESON_MX_SDIO_CONF					0x08
44 	#define MESON_MX_SDIO_CONF_CMD_CLK_DIV_SHIFT		0
45 	#define MESON_MX_SDIO_CONF_CMD_CLK_DIV_WIDTH		10
46 	#define MESON_MX_SDIO_CONF_CMD_DISABLE_CRC		BIT(10)
47 	#define MESON_MX_SDIO_CONF_CMD_OUT_AT_POSITIVE_EDGE	BIT(11)
48 	#define MESON_MX_SDIO_CONF_CMD_ARGUMENT_BITS_MASK	GENMASK(17, 12)
49 	#define MESON_MX_SDIO_CONF_RESP_LATCH_AT_NEGATIVE_EDGE	BIT(18)
50 	#define MESON_MX_SDIO_CONF_DATA_LATCH_AT_NEGATIVE_EDGE	BIT(19)
51 	#define MESON_MX_SDIO_CONF_BUS_WIDTH			BIT(20)
52 	#define MESON_MX_SDIO_CONF_M_ENDIAN_MASK		GENMASK(22, 21)
53 	#define MESON_MX_SDIO_CONF_WRITE_NWR_MASK		GENMASK(28, 23)
54 	#define MESON_MX_SDIO_CONF_WRITE_CRC_OK_STATUS_MASK	GENMASK(31, 29)
55 
56 #define MESON_MX_SDIO_IRQS					0x0c
57 	#define MESON_MX_SDIO_IRQS_STATUS_STATE_MACHINE_MASK	GENMASK(3, 0)
58 	#define MESON_MX_SDIO_IRQS_CMD_BUSY			BIT(4)
59 	#define MESON_MX_SDIO_IRQS_RESP_CRC7_OK			BIT(5)
60 	#define MESON_MX_SDIO_IRQS_DATA_READ_CRC16_OK		BIT(6)
61 	#define MESON_MX_SDIO_IRQS_DATA_WRITE_CRC16_OK		BIT(7)
62 	#define MESON_MX_SDIO_IRQS_IF_INT			BIT(8)
63 	#define MESON_MX_SDIO_IRQS_CMD_INT			BIT(9)
64 	#define MESON_MX_SDIO_IRQS_STATUS_INFO_MASK		GENMASK(15, 12)
65 	#define MESON_MX_SDIO_IRQS_TIMING_OUT_INT		BIT(16)
66 	#define MESON_MX_SDIO_IRQS_AMRISC_TIMING_OUT_INT_EN	BIT(17)
67 	#define MESON_MX_SDIO_IRQS_ARC_TIMING_OUT_INT_EN	BIT(18)
68 	#define MESON_MX_SDIO_IRQS_TIMING_OUT_COUNT_MASK	GENMASK(31, 19)
69 
70 #define MESON_MX_SDIO_IRQC					0x10
71 	#define MESON_MX_SDIO_IRQC_ARC_IF_INT_EN		BIT(3)
72 	#define MESON_MX_SDIO_IRQC_ARC_CMD_INT_EN		BIT(4)
73 	#define MESON_MX_SDIO_IRQC_IF_CONFIG_MASK		GENMASK(7, 6)
74 	#define MESON_MX_SDIO_IRQC_FORCE_DATA_CLK		BIT(8)
75 	#define MESON_MX_SDIO_IRQC_FORCE_DATA_CMD		BIT(9)
76 	#define MESON_MX_SDIO_IRQC_FORCE_DATA_DAT_MASK		GENMASK(13, 10)
77 	#define MESON_MX_SDIO_IRQC_SOFT_RESET			BIT(15)
78 	#define MESON_MX_SDIO_IRQC_FORCE_HALT			BIT(30)
79 	#define MESON_MX_SDIO_IRQC_HALT_HOLE			BIT(31)
80 
81 #define MESON_MX_SDIO_MULT					0x14
82 	#define MESON_MX_SDIO_MULT_PORT_SEL_MASK		GENMASK(1, 0)
83 	#define MESON_MX_SDIO_MULT_MEMORY_STICK_ENABLE		BIT(2)
84 	#define MESON_MX_SDIO_MULT_MEMORY_STICK_SCLK_ALWAYS	BIT(3)
85 	#define MESON_MX_SDIO_MULT_STREAM_ENABLE		BIT(4)
86 	#define MESON_MX_SDIO_MULT_STREAM_8BITS_MODE		BIT(5)
87 	#define MESON_MX_SDIO_MULT_WR_RD_OUT_INDEX		BIT(8)
88 	#define MESON_MX_SDIO_MULT_DAT0_DAT1_SWAPPED		BIT(10)
89 	#define MESON_MX_SDIO_MULT_DAT1_DAT0_SWAPPED		BIT(11)
90 	#define MESON_MX_SDIO_MULT_RESP_READ_INDEX_MASK		GENMASK(15, 12)
91 
92 #define MESON_MX_SDIO_ADDR					0x18
93 
94 #define MESON_MX_SDIO_EXT					0x1c
95 	#define MESON_MX_SDIO_EXT_DATA_RW_NUMBER_MASK		GENMASK(29, 16)
96 
97 #define MESON_MX_SDIO_BOUNCE_REQ_SIZE				(128 * 1024)
98 #define MESON_MX_SDIO_RESPONSE_CRC16_BITS			(16 - 1)
99 #define MESON_MX_SDIO_MAX_SLOTS					3
100 
101 struct meson_mx_mmc_host {
102 	struct device			*controller_dev;
103 
104 	struct clk			*parent_clk;
105 	struct clk			*core_clk;
106 	struct clk_divider		cfg_div;
107 	struct clk			*cfg_div_clk;
108 	struct clk_fixed_factor		fixed_factor;
109 	struct clk			*fixed_factor_clk;
110 
111 	void __iomem			*base;
112 	int				irq;
113 	spinlock_t			irq_lock;
114 
115 	struct timer_list		cmd_timeout;
116 
117 	unsigned int			slot_id;
118 	struct mmc_host			*mmc;
119 
120 	struct mmc_request		*mrq;
121 	struct mmc_command		*cmd;
122 	int				error;
123 };
124 
125 static void meson_mx_mmc_mask_bits(struct mmc_host *mmc, char reg, u32 mask,
126 				   u32 val)
127 {
128 	struct meson_mx_mmc_host *host = mmc_priv(mmc);
129 	u32 regval;
130 
131 	regval = readl(host->base + reg);
132 	regval &= ~mask;
133 	regval |= (val & mask);
134 
135 	writel(regval, host->base + reg);
136 }
137 
138 static void meson_mx_mmc_soft_reset(struct meson_mx_mmc_host *host)
139 {
140 	writel(MESON_MX_SDIO_IRQC_SOFT_RESET, host->base + MESON_MX_SDIO_IRQC);
141 	udelay(2);
142 }
143 
144 static struct mmc_command *meson_mx_mmc_get_next_cmd(struct mmc_command *cmd)
145 {
146 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
147 		return cmd->mrq->cmd;
148 	else if (mmc_op_multi(cmd->opcode) &&
149 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
150 		return cmd->mrq->stop;
151 	else
152 		return NULL;
153 }
154 
155 static void meson_mx_mmc_start_cmd(struct mmc_host *mmc,
156 				   struct mmc_command *cmd)
157 {
158 	struct meson_mx_mmc_host *host = mmc_priv(mmc);
159 	unsigned int pack_size;
160 	unsigned long irqflags, timeout;
161 	u32 mult, send = 0, ext = 0;
162 
163 	host->cmd = cmd;
164 
165 	if (cmd->busy_timeout)
166 		timeout = msecs_to_jiffies(cmd->busy_timeout);
167 	else
168 		timeout = msecs_to_jiffies(1000);
169 
170 	switch (mmc_resp_type(cmd)) {
171 	case MMC_RSP_R1:
172 	case MMC_RSP_R1B:
173 	case MMC_RSP_R3:
174 		/* 7 (CMD) + 32 (response) + 7 (CRC) -1 */
175 		send |= FIELD_PREP(MESON_MX_SDIO_SEND_CMD_RESP_BITS_MASK, 45);
176 		break;
177 	case MMC_RSP_R2:
178 		/* 7 (CMD) + 120 (response) + 7 (CRC) -1 */
179 		send |= FIELD_PREP(MESON_MX_SDIO_SEND_CMD_RESP_BITS_MASK, 133);
180 		send |= MESON_MX_SDIO_SEND_RESP_CRC7_FROM_8;
181 		break;
182 	default:
183 		break;
184 	}
185 
186 	if (!(cmd->flags & MMC_RSP_CRC))
187 		send |= MESON_MX_SDIO_SEND_RESP_WITHOUT_CRC7;
188 
189 	if (cmd->flags & MMC_RSP_BUSY)
190 		send |= MESON_MX_SDIO_SEND_CHECK_DAT0_BUSY;
191 
192 	if (cmd->data) {
193 		send |= FIELD_PREP(MESON_MX_SDIO_SEND_REPEAT_PACKAGE_TIMES_MASK,
194 				   (cmd->data->blocks - 1));
195 
196 		pack_size = cmd->data->blksz * BITS_PER_BYTE;
197 		if (mmc->ios.bus_width == MMC_BUS_WIDTH_4)
198 			pack_size += MESON_MX_SDIO_RESPONSE_CRC16_BITS * 4;
199 		else
200 			pack_size += MESON_MX_SDIO_RESPONSE_CRC16_BITS * 1;
201 
202 		ext |= FIELD_PREP(MESON_MX_SDIO_EXT_DATA_RW_NUMBER_MASK,
203 				  pack_size);
204 
205 		if (cmd->data->flags & MMC_DATA_WRITE)
206 			send |= MESON_MX_SDIO_SEND_DATA;
207 		else
208 			send |= MESON_MX_SDIO_SEND_RESP_HAS_DATA;
209 
210 		cmd->data->bytes_xfered = 0;
211 	}
212 
213 	send |= FIELD_PREP(MESON_MX_SDIO_SEND_COMMAND_INDEX_MASK,
214 			   (0x40 | cmd->opcode));
215 
216 	spin_lock_irqsave(&host->irq_lock, irqflags);
217 
218 	mult = readl(host->base + MESON_MX_SDIO_MULT);
219 	mult &= ~MESON_MX_SDIO_MULT_PORT_SEL_MASK;
220 	mult |= FIELD_PREP(MESON_MX_SDIO_MULT_PORT_SEL_MASK, host->slot_id);
221 	mult |= BIT(31);
222 	writel(mult, host->base + MESON_MX_SDIO_MULT);
223 
224 	/* enable the CMD done interrupt */
225 	meson_mx_mmc_mask_bits(mmc, MESON_MX_SDIO_IRQC,
226 			       MESON_MX_SDIO_IRQC_ARC_CMD_INT_EN,
227 			       MESON_MX_SDIO_IRQC_ARC_CMD_INT_EN);
228 
229 	/* clear pending interrupts */
230 	meson_mx_mmc_mask_bits(mmc, MESON_MX_SDIO_IRQS,
231 			       MESON_MX_SDIO_IRQS_CMD_INT,
232 			       MESON_MX_SDIO_IRQS_CMD_INT);
233 
234 	writel(cmd->arg, host->base + MESON_MX_SDIO_ARGU);
235 	writel(ext, host->base + MESON_MX_SDIO_EXT);
236 	writel(send, host->base + MESON_MX_SDIO_SEND);
237 
238 	spin_unlock_irqrestore(&host->irq_lock, irqflags);
239 
240 	mod_timer(&host->cmd_timeout, jiffies + timeout);
241 }
242 
243 static void meson_mx_mmc_request_done(struct meson_mx_mmc_host *host)
244 {
245 	struct mmc_request *mrq;
246 
247 	mrq = host->mrq;
248 
249 	host->mrq = NULL;
250 	host->cmd = NULL;
251 
252 	mmc_request_done(host->mmc, mrq);
253 }
254 
255 static void meson_mx_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
256 {
257 	struct meson_mx_mmc_host *host = mmc_priv(mmc);
258 	unsigned short vdd = ios->vdd;
259 	unsigned long clk_rate = ios->clock;
260 
261 	switch (ios->bus_width) {
262 	case MMC_BUS_WIDTH_1:
263 		meson_mx_mmc_mask_bits(mmc, MESON_MX_SDIO_CONF,
264 				       MESON_MX_SDIO_CONF_BUS_WIDTH, 0);
265 		break;
266 
267 	case MMC_BUS_WIDTH_4:
268 		meson_mx_mmc_mask_bits(mmc, MESON_MX_SDIO_CONF,
269 				       MESON_MX_SDIO_CONF_BUS_WIDTH,
270 				       MESON_MX_SDIO_CONF_BUS_WIDTH);
271 		break;
272 
273 	case MMC_BUS_WIDTH_8:
274 	default:
275 		dev_err(mmc_dev(mmc), "unsupported bus width: %d\n",
276 			ios->bus_width);
277 		host->error = -EINVAL;
278 		return;
279 	}
280 
281 	host->error = clk_set_rate(host->cfg_div_clk, ios->clock);
282 	if (host->error) {
283 		dev_warn(mmc_dev(mmc),
284 				"failed to set MMC clock to %lu: %d\n",
285 				clk_rate, host->error);
286 		return;
287 	}
288 
289 	mmc->actual_clock = clk_get_rate(host->cfg_div_clk);
290 
291 	switch (ios->power_mode) {
292 	case MMC_POWER_OFF:
293 		vdd = 0;
294 		/* fall through */
295 	case MMC_POWER_UP:
296 		if (!IS_ERR(mmc->supply.vmmc)) {
297 			host->error = mmc_regulator_set_ocr(mmc,
298 							    mmc->supply.vmmc,
299 							    vdd);
300 			if (host->error)
301 				return;
302 		}
303 		break;
304 	}
305 }
306 
307 static int meson_mx_mmc_map_dma(struct mmc_host *mmc, struct mmc_request *mrq)
308 {
309 	struct mmc_data *data = mrq->data;
310 	int dma_len;
311 	struct scatterlist *sg;
312 
313 	if (!data)
314 		return 0;
315 
316 	sg = data->sg;
317 	if (sg->offset & 3 || sg->length & 3) {
318 		dev_err(mmc_dev(mmc),
319 			"unaligned scatterlist: offset %x length %d\n",
320 			sg->offset, sg->length);
321 		return -EINVAL;
322 	}
323 
324 	dma_len = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
325 			     mmc_get_dma_dir(data));
326 	if (dma_len <= 0) {
327 		dev_err(mmc_dev(mmc), "dma_map_sg failed\n");
328 		return -ENOMEM;
329 	}
330 
331 	return 0;
332 }
333 
334 static void meson_mx_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
335 {
336 	struct meson_mx_mmc_host *host = mmc_priv(mmc);
337 	struct mmc_command *cmd = mrq->cmd;
338 
339 	if (!host->error)
340 		host->error = meson_mx_mmc_map_dma(mmc, mrq);
341 
342 	if (host->error) {
343 		cmd->error = host->error;
344 		mmc_request_done(mmc, mrq);
345 		return;
346 	}
347 
348 	host->mrq = mrq;
349 
350 	if (mrq->data)
351 		writel(sg_dma_address(mrq->data->sg),
352 		       host->base + MESON_MX_SDIO_ADDR);
353 
354 	if (mrq->sbc)
355 		meson_mx_mmc_start_cmd(mmc, mrq->sbc);
356 	else
357 		meson_mx_mmc_start_cmd(mmc, mrq->cmd);
358 }
359 
360 static void meson_mx_mmc_read_response(struct mmc_host *mmc,
361 				       struct mmc_command *cmd)
362 {
363 	struct meson_mx_mmc_host *host = mmc_priv(mmc);
364 	u32 mult;
365 	int i, resp[4];
366 
367 	mult = readl(host->base + MESON_MX_SDIO_MULT);
368 	mult |= MESON_MX_SDIO_MULT_WR_RD_OUT_INDEX;
369 	mult &= ~MESON_MX_SDIO_MULT_RESP_READ_INDEX_MASK;
370 	mult |= FIELD_PREP(MESON_MX_SDIO_MULT_RESP_READ_INDEX_MASK, 0);
371 	writel(mult, host->base + MESON_MX_SDIO_MULT);
372 
373 	if (cmd->flags & MMC_RSP_136) {
374 		for (i = 0; i <= 3; i++)
375 			resp[3 - i] = readl(host->base + MESON_MX_SDIO_ARGU);
376 		cmd->resp[0] = (resp[0] << 8) | ((resp[1] >> 24) & 0xff);
377 		cmd->resp[1] = (resp[1] << 8) | ((resp[2] >> 24) & 0xff);
378 		cmd->resp[2] = (resp[2] << 8) | ((resp[3] >> 24) & 0xff);
379 		cmd->resp[3] = (resp[3] << 8);
380 	} else if (cmd->flags & MMC_RSP_PRESENT) {
381 		cmd->resp[0] = readl(host->base + MESON_MX_SDIO_ARGU);
382 	}
383 }
384 
385 static irqreturn_t meson_mx_mmc_process_cmd_irq(struct meson_mx_mmc_host *host,
386 						u32 irqs, u32 send)
387 {
388 	struct mmc_command *cmd = host->cmd;
389 
390 	/*
391 	 * NOTE: even though it shouldn't happen we sometimes get command
392 	 * interrupts twice (at least this is what it looks like). Ideally
393 	 * we find out why this happens and warn here as soon as it occurs.
394 	 */
395 	if (!cmd)
396 		return IRQ_HANDLED;
397 
398 	cmd->error = 0;
399 	meson_mx_mmc_read_response(host->mmc, cmd);
400 
401 	if (cmd->data) {
402 		if (!((irqs & MESON_MX_SDIO_IRQS_DATA_READ_CRC16_OK) ||
403 		      (irqs & MESON_MX_SDIO_IRQS_DATA_WRITE_CRC16_OK)))
404 			cmd->error = -EILSEQ;
405 	} else {
406 		if (!((irqs & MESON_MX_SDIO_IRQS_RESP_CRC7_OK) ||
407 		      (send & MESON_MX_SDIO_SEND_RESP_WITHOUT_CRC7)))
408 			cmd->error = -EILSEQ;
409 	}
410 
411 	return IRQ_WAKE_THREAD;
412 }
413 
414 static irqreturn_t meson_mx_mmc_irq(int irq, void *data)
415 {
416 	struct meson_mx_mmc_host *host = (void *) data;
417 	u32 irqs, send;
418 	unsigned long irqflags;
419 	irqreturn_t ret;
420 
421 	spin_lock_irqsave(&host->irq_lock, irqflags);
422 
423 	irqs = readl(host->base + MESON_MX_SDIO_IRQS);
424 	send = readl(host->base + MESON_MX_SDIO_SEND);
425 
426 	if (irqs & MESON_MX_SDIO_IRQS_CMD_INT)
427 		ret = meson_mx_mmc_process_cmd_irq(host, irqs, send);
428 	else
429 		ret = IRQ_HANDLED;
430 
431 	/* finally ACK all pending interrupts */
432 	writel(irqs, host->base + MESON_MX_SDIO_IRQS);
433 
434 	spin_unlock_irqrestore(&host->irq_lock, irqflags);
435 
436 	return ret;
437 }
438 
439 static irqreturn_t meson_mx_mmc_irq_thread(int irq, void *irq_data)
440 {
441 	struct meson_mx_mmc_host *host = (void *) irq_data;
442 	struct mmc_command *cmd = host->cmd, *next_cmd;
443 
444 	if (WARN_ON(!cmd))
445 		return IRQ_HANDLED;
446 
447 	del_timer_sync(&host->cmd_timeout);
448 
449 	if (cmd->data) {
450 		dma_unmap_sg(mmc_dev(host->mmc), cmd->data->sg,
451 				cmd->data->sg_len,
452 				mmc_get_dma_dir(cmd->data));
453 
454 		cmd->data->bytes_xfered = cmd->data->blksz * cmd->data->blocks;
455 	}
456 
457 	next_cmd = meson_mx_mmc_get_next_cmd(cmd);
458 	if (next_cmd)
459 		meson_mx_mmc_start_cmd(host->mmc, next_cmd);
460 	else
461 		meson_mx_mmc_request_done(host);
462 
463 	return IRQ_HANDLED;
464 }
465 
466 static void meson_mx_mmc_timeout(struct timer_list *t)
467 {
468 	struct meson_mx_mmc_host *host = from_timer(host, t, cmd_timeout);
469 	unsigned long irqflags;
470 	u32 irqc;
471 
472 	spin_lock_irqsave(&host->irq_lock, irqflags);
473 
474 	/* disable the CMD interrupt */
475 	irqc = readl(host->base + MESON_MX_SDIO_IRQC);
476 	irqc &= ~MESON_MX_SDIO_IRQC_ARC_CMD_INT_EN;
477 	writel(irqc, host->base + MESON_MX_SDIO_IRQC);
478 
479 	spin_unlock_irqrestore(&host->irq_lock, irqflags);
480 
481 	/*
482 	 * skip the timeout handling if the interrupt handler already processed
483 	 * the command.
484 	 */
485 	if (!host->cmd)
486 		return;
487 
488 	dev_dbg(mmc_dev(host->mmc),
489 		"Timeout on CMD%u (IRQS = 0x%08x, ARGU = 0x%08x)\n",
490 		host->cmd->opcode, readl(host->base + MESON_MX_SDIO_IRQS),
491 		readl(host->base + MESON_MX_SDIO_ARGU));
492 
493 	host->cmd->error = -ETIMEDOUT;
494 
495 	meson_mx_mmc_request_done(host);
496 }
497 
498 static struct mmc_host_ops meson_mx_mmc_ops = {
499 	.request		= meson_mx_mmc_request,
500 	.set_ios		= meson_mx_mmc_set_ios,
501 	.get_cd			= mmc_gpio_get_cd,
502 	.get_ro			= mmc_gpio_get_ro,
503 };
504 
505 static struct platform_device *meson_mx_mmc_slot_pdev(struct device *parent)
506 {
507 	struct device_node *slot_node;
508 	struct platform_device *pdev;
509 
510 	/*
511 	 * TODO: the MMC core framework currently does not support
512 	 * controllers with multiple slots properly. So we only register
513 	 * the first slot for now
514 	 */
515 	slot_node = of_get_compatible_child(parent->of_node, "mmc-slot");
516 	if (!slot_node) {
517 		dev_warn(parent, "no 'mmc-slot' sub-node found\n");
518 		return ERR_PTR(-ENOENT);
519 	}
520 
521 	pdev = of_platform_device_create(slot_node, NULL, parent);
522 	of_node_put(slot_node);
523 
524 	return pdev;
525 }
526 
527 static int meson_mx_mmc_add_host(struct meson_mx_mmc_host *host)
528 {
529 	struct mmc_host *mmc = host->mmc;
530 	struct device *slot_dev = mmc_dev(mmc);
531 	int ret;
532 
533 	if (of_property_read_u32(slot_dev->of_node, "reg", &host->slot_id)) {
534 		dev_err(slot_dev, "missing 'reg' property\n");
535 		return -EINVAL;
536 	}
537 
538 	if (host->slot_id >= MESON_MX_SDIO_MAX_SLOTS) {
539 		dev_err(slot_dev, "invalid 'reg' property value %d\n",
540 			host->slot_id);
541 		return -EINVAL;
542 	}
543 
544 	/* Get regulators and the supported OCR mask */
545 	ret = mmc_regulator_get_supply(mmc);
546 	if (ret)
547 		return ret;
548 
549 	mmc->max_req_size = MESON_MX_SDIO_BOUNCE_REQ_SIZE;
550 	mmc->max_seg_size = mmc->max_req_size;
551 	mmc->max_blk_count =
552 		FIELD_GET(MESON_MX_SDIO_SEND_REPEAT_PACKAGE_TIMES_MASK,
553 			  0xffffffff);
554 	mmc->max_blk_size = FIELD_GET(MESON_MX_SDIO_EXT_DATA_RW_NUMBER_MASK,
555 				      0xffffffff);
556 	mmc->max_blk_size -= (4 * MESON_MX_SDIO_RESPONSE_CRC16_BITS);
557 	mmc->max_blk_size /= BITS_PER_BYTE;
558 
559 	/* Get the min and max supported clock rates */
560 	mmc->f_min = clk_round_rate(host->cfg_div_clk, 1);
561 	mmc->f_max = clk_round_rate(host->cfg_div_clk,
562 				    clk_get_rate(host->parent_clk));
563 
564 	mmc->caps |= MMC_CAP_ERASE | MMC_CAP_CMD23 | MMC_CAP_WAIT_WHILE_BUSY;
565 	mmc->ops = &meson_mx_mmc_ops;
566 
567 	ret = mmc_of_parse(mmc);
568 	if (ret)
569 		return ret;
570 
571 	ret = mmc_add_host(mmc);
572 	if (ret)
573 		return ret;
574 
575 	return 0;
576 }
577 
578 static int meson_mx_mmc_register_clks(struct meson_mx_mmc_host *host)
579 {
580 	struct clk_init_data init;
581 	const char *clk_div_parent, *clk_fixed_factor_parent;
582 
583 	clk_fixed_factor_parent = __clk_get_name(host->parent_clk);
584 	init.name = devm_kasprintf(host->controller_dev, GFP_KERNEL,
585 				   "%s#fixed_factor",
586 				   dev_name(host->controller_dev));
587 	if (!init.name)
588 		return -ENOMEM;
589 
590 	init.ops = &clk_fixed_factor_ops;
591 	init.flags = 0;
592 	init.parent_names = &clk_fixed_factor_parent;
593 	init.num_parents = 1;
594 	host->fixed_factor.div = 2;
595 	host->fixed_factor.mult = 1;
596 	host->fixed_factor.hw.init = &init;
597 
598 	host->fixed_factor_clk = devm_clk_register(host->controller_dev,
599 						 &host->fixed_factor.hw);
600 	if (WARN_ON(IS_ERR(host->fixed_factor_clk)))
601 		return PTR_ERR(host->fixed_factor_clk);
602 
603 	clk_div_parent = __clk_get_name(host->fixed_factor_clk);
604 	init.name = devm_kasprintf(host->controller_dev, GFP_KERNEL,
605 				   "%s#div", dev_name(host->controller_dev));
606 	if (!init.name)
607 		return -ENOMEM;
608 
609 	init.ops = &clk_divider_ops;
610 	init.flags = CLK_SET_RATE_PARENT;
611 	init.parent_names = &clk_div_parent;
612 	init.num_parents = 1;
613 	host->cfg_div.reg = host->base + MESON_MX_SDIO_CONF;
614 	host->cfg_div.shift = MESON_MX_SDIO_CONF_CMD_CLK_DIV_SHIFT;
615 	host->cfg_div.width = MESON_MX_SDIO_CONF_CMD_CLK_DIV_WIDTH;
616 	host->cfg_div.hw.init = &init;
617 	host->cfg_div.flags = CLK_DIVIDER_ALLOW_ZERO;
618 
619 	host->cfg_div_clk = devm_clk_register(host->controller_dev,
620 					      &host->cfg_div.hw);
621 	if (WARN_ON(IS_ERR(host->cfg_div_clk)))
622 		return PTR_ERR(host->cfg_div_clk);
623 
624 	return 0;
625 }
626 
627 static int meson_mx_mmc_probe(struct platform_device *pdev)
628 {
629 	struct platform_device *slot_pdev;
630 	struct mmc_host *mmc;
631 	struct meson_mx_mmc_host *host;
632 	int ret, irq;
633 	u32 conf;
634 
635 	slot_pdev = meson_mx_mmc_slot_pdev(&pdev->dev);
636 	if (!slot_pdev)
637 		return -ENODEV;
638 	else if (IS_ERR(slot_pdev))
639 		return PTR_ERR(slot_pdev);
640 
641 	mmc = mmc_alloc_host(sizeof(*host), &slot_pdev->dev);
642 	if (!mmc) {
643 		ret = -ENOMEM;
644 		goto error_unregister_slot_pdev;
645 	}
646 
647 	host = mmc_priv(mmc);
648 	host->mmc = mmc;
649 	host->controller_dev = &pdev->dev;
650 
651 	spin_lock_init(&host->irq_lock);
652 	timer_setup(&host->cmd_timeout, meson_mx_mmc_timeout, 0);
653 
654 	platform_set_drvdata(pdev, host);
655 
656 	host->base = devm_platform_ioremap_resource(pdev, 0);
657 	if (IS_ERR(host->base)) {
658 		ret = PTR_ERR(host->base);
659 		goto error_free_mmc;
660 	}
661 
662 	irq = platform_get_irq(pdev, 0);
663 	ret = devm_request_threaded_irq(host->controller_dev, irq,
664 					meson_mx_mmc_irq,
665 					meson_mx_mmc_irq_thread, IRQF_ONESHOT,
666 					NULL, host);
667 	if (ret)
668 		goto error_free_mmc;
669 
670 	host->core_clk = devm_clk_get(host->controller_dev, "core");
671 	if (IS_ERR(host->core_clk)) {
672 		ret = PTR_ERR(host->core_clk);
673 		goto error_free_mmc;
674 	}
675 
676 	host->parent_clk = devm_clk_get(host->controller_dev, "clkin");
677 	if (IS_ERR(host->parent_clk)) {
678 		ret = PTR_ERR(host->parent_clk);
679 		goto error_free_mmc;
680 	}
681 
682 	ret = meson_mx_mmc_register_clks(host);
683 	if (ret)
684 		goto error_free_mmc;
685 
686 	ret = clk_prepare_enable(host->core_clk);
687 	if (ret) {
688 		dev_err(host->controller_dev, "Failed to enable core clock\n");
689 		goto error_free_mmc;
690 	}
691 
692 	ret = clk_prepare_enable(host->cfg_div_clk);
693 	if (ret) {
694 		dev_err(host->controller_dev, "Failed to enable MMC clock\n");
695 		goto error_disable_core_clk;
696 	}
697 
698 	conf = 0;
699 	conf |= FIELD_PREP(MESON_MX_SDIO_CONF_CMD_ARGUMENT_BITS_MASK, 39);
700 	conf |= FIELD_PREP(MESON_MX_SDIO_CONF_M_ENDIAN_MASK, 0x3);
701 	conf |= FIELD_PREP(MESON_MX_SDIO_CONF_WRITE_NWR_MASK, 0x2);
702 	conf |= FIELD_PREP(MESON_MX_SDIO_CONF_WRITE_CRC_OK_STATUS_MASK, 0x2);
703 	writel(conf, host->base + MESON_MX_SDIO_CONF);
704 
705 	meson_mx_mmc_soft_reset(host);
706 
707 	ret = meson_mx_mmc_add_host(host);
708 	if (ret)
709 		goto error_disable_clks;
710 
711 	return 0;
712 
713 error_disable_clks:
714 	clk_disable_unprepare(host->cfg_div_clk);
715 error_disable_core_clk:
716 	clk_disable_unprepare(host->core_clk);
717 error_free_mmc:
718 	mmc_free_host(mmc);
719 error_unregister_slot_pdev:
720 	of_platform_device_destroy(&slot_pdev->dev, NULL);
721 	return ret;
722 }
723 
724 static int meson_mx_mmc_remove(struct platform_device *pdev)
725 {
726 	struct meson_mx_mmc_host *host = platform_get_drvdata(pdev);
727 	struct device *slot_dev = mmc_dev(host->mmc);
728 
729 	del_timer_sync(&host->cmd_timeout);
730 
731 	mmc_remove_host(host->mmc);
732 
733 	of_platform_device_destroy(slot_dev, NULL);
734 
735 	clk_disable_unprepare(host->cfg_div_clk);
736 	clk_disable_unprepare(host->core_clk);
737 
738 	mmc_free_host(host->mmc);
739 
740 	return 0;
741 }
742 
743 static const struct of_device_id meson_mx_mmc_of_match[] = {
744 	{ .compatible = "amlogic,meson8-sdio", },
745 	{ .compatible = "amlogic,meson8b-sdio", },
746 	{ /* sentinel */ }
747 };
748 MODULE_DEVICE_TABLE(of, meson_mx_mmc_of_match);
749 
750 static struct platform_driver meson_mx_mmc_driver = {
751 	.probe   = meson_mx_mmc_probe,
752 	.remove  = meson_mx_mmc_remove,
753 	.driver  = {
754 		.name = "meson-mx-sdio",
755 		.of_match_table = of_match_ptr(meson_mx_mmc_of_match),
756 	},
757 };
758 
759 module_platform_driver(meson_mx_mmc_driver);
760 
761 MODULE_DESCRIPTION("Meson6, Meson8 and Meson8b SDIO/MMC Host Driver");
762 MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
763 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
764 MODULE_LICENSE("GPL v2");
765