xref: /openbmc/linux/drivers/mmc/host/meson-mx-sdio.c (revision 3ddc8b84)
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 	if (host->cmd->error)
250 		meson_mx_mmc_soft_reset(host);
251 
252 	host->mrq = NULL;
253 	host->cmd = NULL;
254 
255 	mmc_request_done(host->mmc, mrq);
256 }
257 
258 static void meson_mx_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
259 {
260 	struct meson_mx_mmc_host *host = mmc_priv(mmc);
261 	unsigned short vdd = ios->vdd;
262 	unsigned long clk_rate = ios->clock;
263 
264 	switch (ios->bus_width) {
265 	case MMC_BUS_WIDTH_1:
266 		meson_mx_mmc_mask_bits(mmc, MESON_MX_SDIO_CONF,
267 				       MESON_MX_SDIO_CONF_BUS_WIDTH, 0);
268 		break;
269 
270 	case MMC_BUS_WIDTH_4:
271 		meson_mx_mmc_mask_bits(mmc, MESON_MX_SDIO_CONF,
272 				       MESON_MX_SDIO_CONF_BUS_WIDTH,
273 				       MESON_MX_SDIO_CONF_BUS_WIDTH);
274 		break;
275 
276 	case MMC_BUS_WIDTH_8:
277 	default:
278 		dev_err(mmc_dev(mmc), "unsupported bus width: %d\n",
279 			ios->bus_width);
280 		host->error = -EINVAL;
281 		return;
282 	}
283 
284 	host->error = clk_set_rate(host->cfg_div_clk, ios->clock);
285 	if (host->error) {
286 		dev_warn(mmc_dev(mmc),
287 				"failed to set MMC clock to %lu: %d\n",
288 				clk_rate, host->error);
289 		return;
290 	}
291 
292 	mmc->actual_clock = clk_get_rate(host->cfg_div_clk);
293 
294 	switch (ios->power_mode) {
295 	case MMC_POWER_OFF:
296 		vdd = 0;
297 		fallthrough;
298 	case MMC_POWER_UP:
299 		if (!IS_ERR(mmc->supply.vmmc)) {
300 			host->error = mmc_regulator_set_ocr(mmc,
301 							    mmc->supply.vmmc,
302 							    vdd);
303 			if (host->error)
304 				return;
305 		}
306 		break;
307 	}
308 }
309 
310 static int meson_mx_mmc_map_dma(struct mmc_host *mmc, struct mmc_request *mrq)
311 {
312 	struct mmc_data *data = mrq->data;
313 	int dma_len;
314 	struct scatterlist *sg;
315 
316 	if (!data)
317 		return 0;
318 
319 	sg = data->sg;
320 	if (sg->offset & 3 || sg->length & 3) {
321 		dev_err(mmc_dev(mmc),
322 			"unaligned scatterlist: offset %x length %d\n",
323 			sg->offset, sg->length);
324 		return -EINVAL;
325 	}
326 
327 	dma_len = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
328 			     mmc_get_dma_dir(data));
329 	if (dma_len <= 0) {
330 		dev_err(mmc_dev(mmc), "dma_map_sg failed\n");
331 		return -ENOMEM;
332 	}
333 
334 	return 0;
335 }
336 
337 static void meson_mx_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
338 {
339 	struct meson_mx_mmc_host *host = mmc_priv(mmc);
340 	struct mmc_command *cmd = mrq->cmd;
341 
342 	if (!host->error)
343 		host->error = meson_mx_mmc_map_dma(mmc, mrq);
344 
345 	if (host->error) {
346 		cmd->error = host->error;
347 		mmc_request_done(mmc, mrq);
348 		return;
349 	}
350 
351 	host->mrq = mrq;
352 
353 	if (mrq->data)
354 		writel(sg_dma_address(mrq->data->sg),
355 		       host->base + MESON_MX_SDIO_ADDR);
356 
357 	if (mrq->sbc)
358 		meson_mx_mmc_start_cmd(mmc, mrq->sbc);
359 	else
360 		meson_mx_mmc_start_cmd(mmc, mrq->cmd);
361 }
362 
363 static void meson_mx_mmc_read_response(struct mmc_host *mmc,
364 				       struct mmc_command *cmd)
365 {
366 	struct meson_mx_mmc_host *host = mmc_priv(mmc);
367 	u32 mult;
368 	int i, resp[4];
369 
370 	mult = readl(host->base + MESON_MX_SDIO_MULT);
371 	mult |= MESON_MX_SDIO_MULT_WR_RD_OUT_INDEX;
372 	mult &= ~MESON_MX_SDIO_MULT_RESP_READ_INDEX_MASK;
373 	mult |= FIELD_PREP(MESON_MX_SDIO_MULT_RESP_READ_INDEX_MASK, 0);
374 	writel(mult, host->base + MESON_MX_SDIO_MULT);
375 
376 	if (cmd->flags & MMC_RSP_136) {
377 		for (i = 0; i <= 3; i++)
378 			resp[3 - i] = readl(host->base + MESON_MX_SDIO_ARGU);
379 		cmd->resp[0] = (resp[0] << 8) | ((resp[1] >> 24) & 0xff);
380 		cmd->resp[1] = (resp[1] << 8) | ((resp[2] >> 24) & 0xff);
381 		cmd->resp[2] = (resp[2] << 8) | ((resp[3] >> 24) & 0xff);
382 		cmd->resp[3] = (resp[3] << 8);
383 	} else if (cmd->flags & MMC_RSP_PRESENT) {
384 		cmd->resp[0] = readl(host->base + MESON_MX_SDIO_ARGU);
385 	}
386 }
387 
388 static irqreturn_t meson_mx_mmc_process_cmd_irq(struct meson_mx_mmc_host *host,
389 						u32 irqs, u32 send)
390 {
391 	struct mmc_command *cmd = host->cmd;
392 
393 	/*
394 	 * NOTE: even though it shouldn't happen we sometimes get command
395 	 * interrupts twice (at least this is what it looks like). Ideally
396 	 * we find out why this happens and warn here as soon as it occurs.
397 	 */
398 	if (!cmd)
399 		return IRQ_HANDLED;
400 
401 	cmd->error = 0;
402 	meson_mx_mmc_read_response(host->mmc, cmd);
403 
404 	if (cmd->data) {
405 		if (!((irqs & MESON_MX_SDIO_IRQS_DATA_READ_CRC16_OK) ||
406 		      (irqs & MESON_MX_SDIO_IRQS_DATA_WRITE_CRC16_OK)))
407 			cmd->error = -EILSEQ;
408 	} else {
409 		if (!((irqs & MESON_MX_SDIO_IRQS_RESP_CRC7_OK) ||
410 		      (send & MESON_MX_SDIO_SEND_RESP_WITHOUT_CRC7)))
411 			cmd->error = -EILSEQ;
412 	}
413 
414 	return IRQ_WAKE_THREAD;
415 }
416 
417 static irqreturn_t meson_mx_mmc_irq(int irq, void *data)
418 {
419 	struct meson_mx_mmc_host *host = (void *) data;
420 	u32 irqs, send;
421 	irqreturn_t ret;
422 
423 	spin_lock(&host->irq_lock);
424 
425 	irqs = readl(host->base + MESON_MX_SDIO_IRQS);
426 	send = readl(host->base + MESON_MX_SDIO_SEND);
427 
428 	if (irqs & MESON_MX_SDIO_IRQS_CMD_INT)
429 		ret = meson_mx_mmc_process_cmd_irq(host, irqs, send);
430 	else
431 		ret = IRQ_HANDLED;
432 
433 	/* finally ACK all pending interrupts */
434 	writel(irqs, host->base + MESON_MX_SDIO_IRQS);
435 
436 	spin_unlock(&host->irq_lock);
437 
438 	return ret;
439 }
440 
441 static irqreturn_t meson_mx_mmc_irq_thread(int irq, void *irq_data)
442 {
443 	struct meson_mx_mmc_host *host = (void *) irq_data;
444 	struct mmc_command *cmd = host->cmd, *next_cmd;
445 
446 	if (WARN_ON(!cmd))
447 		return IRQ_HANDLED;
448 
449 	del_timer_sync(&host->cmd_timeout);
450 
451 	if (cmd->data) {
452 		dma_unmap_sg(mmc_dev(host->mmc), cmd->data->sg,
453 				cmd->data->sg_len,
454 				mmc_get_dma_dir(cmd->data));
455 
456 		cmd->data->bytes_xfered = cmd->data->blksz * cmd->data->blocks;
457 	}
458 
459 	next_cmd = meson_mx_mmc_get_next_cmd(cmd);
460 	if (next_cmd)
461 		meson_mx_mmc_start_cmd(host->mmc, next_cmd);
462 	else
463 		meson_mx_mmc_request_done(host);
464 
465 	return IRQ_HANDLED;
466 }
467 
468 static void meson_mx_mmc_timeout(struct timer_list *t)
469 {
470 	struct meson_mx_mmc_host *host = from_timer(host, t, cmd_timeout);
471 	unsigned long irqflags;
472 	u32 irqc;
473 
474 	spin_lock_irqsave(&host->irq_lock, irqflags);
475 
476 	/* disable the CMD interrupt */
477 	irqc = readl(host->base + MESON_MX_SDIO_IRQC);
478 	irqc &= ~MESON_MX_SDIO_IRQC_ARC_CMD_INT_EN;
479 	writel(irqc, host->base + MESON_MX_SDIO_IRQC);
480 
481 	spin_unlock_irqrestore(&host->irq_lock, irqflags);
482 
483 	/*
484 	 * skip the timeout handling if the interrupt handler already processed
485 	 * the command.
486 	 */
487 	if (!host->cmd)
488 		return;
489 
490 	dev_dbg(mmc_dev(host->mmc),
491 		"Timeout on CMD%u (IRQS = 0x%08x, ARGU = 0x%08x)\n",
492 		host->cmd->opcode, readl(host->base + MESON_MX_SDIO_IRQS),
493 		readl(host->base + MESON_MX_SDIO_ARGU));
494 
495 	host->cmd->error = -ETIMEDOUT;
496 
497 	meson_mx_mmc_request_done(host);
498 }
499 
500 static struct mmc_host_ops meson_mx_mmc_ops = {
501 	.request		= meson_mx_mmc_request,
502 	.set_ios		= meson_mx_mmc_set_ios,
503 	.get_cd			= mmc_gpio_get_cd,
504 	.get_ro			= mmc_gpio_get_ro,
505 };
506 
507 static struct platform_device *meson_mx_mmc_slot_pdev(struct device *parent)
508 {
509 	struct device_node *slot_node;
510 	struct platform_device *pdev;
511 
512 	/*
513 	 * TODO: the MMC core framework currently does not support
514 	 * controllers with multiple slots properly. So we only register
515 	 * the first slot for now
516 	 */
517 	slot_node = of_get_compatible_child(parent->of_node, "mmc-slot");
518 	if (!slot_node) {
519 		dev_warn(parent, "no 'mmc-slot' sub-node found\n");
520 		return ERR_PTR(-ENOENT);
521 	}
522 
523 	pdev = of_platform_device_create(slot_node, NULL, parent);
524 	of_node_put(slot_node);
525 
526 	return pdev;
527 }
528 
529 static int meson_mx_mmc_add_host(struct meson_mx_mmc_host *host)
530 {
531 	struct mmc_host *mmc = host->mmc;
532 	struct device *slot_dev = mmc_dev(mmc);
533 	int ret;
534 
535 	if (of_property_read_u32(slot_dev->of_node, "reg", &host->slot_id)) {
536 		dev_err(slot_dev, "missing 'reg' property\n");
537 		return -EINVAL;
538 	}
539 
540 	if (host->slot_id >= MESON_MX_SDIO_MAX_SLOTS) {
541 		dev_err(slot_dev, "invalid 'reg' property value %d\n",
542 			host->slot_id);
543 		return -EINVAL;
544 	}
545 
546 	/* Get regulators and the supported OCR mask */
547 	ret = mmc_regulator_get_supply(mmc);
548 	if (ret)
549 		return ret;
550 
551 	mmc->max_req_size = MESON_MX_SDIO_BOUNCE_REQ_SIZE;
552 	mmc->max_seg_size = mmc->max_req_size;
553 	mmc->max_blk_count =
554 		FIELD_GET(MESON_MX_SDIO_SEND_REPEAT_PACKAGE_TIMES_MASK,
555 			  0xffffffff);
556 	mmc->max_blk_size = FIELD_GET(MESON_MX_SDIO_EXT_DATA_RW_NUMBER_MASK,
557 				      0xffffffff);
558 	mmc->max_blk_size -= (4 * MESON_MX_SDIO_RESPONSE_CRC16_BITS);
559 	mmc->max_blk_size /= BITS_PER_BYTE;
560 
561 	/* Get the min and max supported clock rates */
562 	mmc->f_min = clk_round_rate(host->cfg_div_clk, 1);
563 	mmc->f_max = clk_round_rate(host->cfg_div_clk,
564 				    clk_get_rate(host->parent_clk));
565 
566 	mmc->caps |= MMC_CAP_CMD23 | MMC_CAP_WAIT_WHILE_BUSY;
567 	mmc->ops = &meson_mx_mmc_ops;
568 
569 	ret = mmc_of_parse(mmc);
570 	if (ret)
571 		return ret;
572 
573 	ret = mmc_add_host(mmc);
574 	if (ret)
575 		return ret;
576 
577 	return 0;
578 }
579 
580 static int meson_mx_mmc_register_clks(struct meson_mx_mmc_host *host)
581 {
582 	struct clk_init_data init;
583 	const char *clk_div_parent, *clk_fixed_factor_parent;
584 
585 	clk_fixed_factor_parent = __clk_get_name(host->parent_clk);
586 	init.name = devm_kasprintf(host->controller_dev, GFP_KERNEL,
587 				   "%s#fixed_factor",
588 				   dev_name(host->controller_dev));
589 	if (!init.name)
590 		return -ENOMEM;
591 
592 	init.ops = &clk_fixed_factor_ops;
593 	init.flags = 0;
594 	init.parent_names = &clk_fixed_factor_parent;
595 	init.num_parents = 1;
596 	host->fixed_factor.div = 2;
597 	host->fixed_factor.mult = 1;
598 	host->fixed_factor.hw.init = &init;
599 
600 	host->fixed_factor_clk = devm_clk_register(host->controller_dev,
601 						 &host->fixed_factor.hw);
602 	if (WARN_ON(IS_ERR(host->fixed_factor_clk)))
603 		return PTR_ERR(host->fixed_factor_clk);
604 
605 	clk_div_parent = __clk_get_name(host->fixed_factor_clk);
606 	init.name = devm_kasprintf(host->controller_dev, GFP_KERNEL,
607 				   "%s#div", dev_name(host->controller_dev));
608 	if (!init.name)
609 		return -ENOMEM;
610 
611 	init.ops = &clk_divider_ops;
612 	init.flags = CLK_SET_RATE_PARENT;
613 	init.parent_names = &clk_div_parent;
614 	init.num_parents = 1;
615 	host->cfg_div.reg = host->base + MESON_MX_SDIO_CONF;
616 	host->cfg_div.shift = MESON_MX_SDIO_CONF_CMD_CLK_DIV_SHIFT;
617 	host->cfg_div.width = MESON_MX_SDIO_CONF_CMD_CLK_DIV_WIDTH;
618 	host->cfg_div.hw.init = &init;
619 	host->cfg_div.flags = CLK_DIVIDER_ALLOW_ZERO;
620 
621 	host->cfg_div_clk = devm_clk_register(host->controller_dev,
622 					      &host->cfg_div.hw);
623 	if (WARN_ON(IS_ERR(host->cfg_div_clk)))
624 		return PTR_ERR(host->cfg_div_clk);
625 
626 	return 0;
627 }
628 
629 static int meson_mx_mmc_probe(struct platform_device *pdev)
630 {
631 	struct platform_device *slot_pdev;
632 	struct mmc_host *mmc;
633 	struct meson_mx_mmc_host *host;
634 	int ret, irq;
635 	u32 conf;
636 
637 	slot_pdev = meson_mx_mmc_slot_pdev(&pdev->dev);
638 	if (!slot_pdev)
639 		return -ENODEV;
640 	else if (IS_ERR(slot_pdev))
641 		return PTR_ERR(slot_pdev);
642 
643 	mmc = mmc_alloc_host(sizeof(*host), &slot_pdev->dev);
644 	if (!mmc) {
645 		ret = -ENOMEM;
646 		goto error_unregister_slot_pdev;
647 	}
648 
649 	host = mmc_priv(mmc);
650 	host->mmc = mmc;
651 	host->controller_dev = &pdev->dev;
652 
653 	spin_lock_init(&host->irq_lock);
654 	timer_setup(&host->cmd_timeout, meson_mx_mmc_timeout, 0);
655 
656 	platform_set_drvdata(pdev, host);
657 
658 	host->base = devm_platform_ioremap_resource(pdev, 0);
659 	if (IS_ERR(host->base)) {
660 		ret = PTR_ERR(host->base);
661 		goto error_free_mmc;
662 	}
663 
664 	irq = platform_get_irq(pdev, 0);
665 	if (irq < 0) {
666 		ret = irq;
667 		goto error_free_mmc;
668 	}
669 
670 	ret = devm_request_threaded_irq(host->controller_dev, irq,
671 					meson_mx_mmc_irq,
672 					meson_mx_mmc_irq_thread, IRQF_ONESHOT,
673 					NULL, host);
674 	if (ret)
675 		goto error_free_mmc;
676 
677 	host->core_clk = devm_clk_get(host->controller_dev, "core");
678 	if (IS_ERR(host->core_clk)) {
679 		ret = PTR_ERR(host->core_clk);
680 		goto error_free_mmc;
681 	}
682 
683 	host->parent_clk = devm_clk_get(host->controller_dev, "clkin");
684 	if (IS_ERR(host->parent_clk)) {
685 		ret = PTR_ERR(host->parent_clk);
686 		goto error_free_mmc;
687 	}
688 
689 	ret = meson_mx_mmc_register_clks(host);
690 	if (ret)
691 		goto error_free_mmc;
692 
693 	ret = clk_prepare_enable(host->core_clk);
694 	if (ret) {
695 		dev_err(host->controller_dev, "Failed to enable core clock\n");
696 		goto error_free_mmc;
697 	}
698 
699 	ret = clk_prepare_enable(host->cfg_div_clk);
700 	if (ret) {
701 		dev_err(host->controller_dev, "Failed to enable MMC clock\n");
702 		goto error_disable_core_clk;
703 	}
704 
705 	conf = 0;
706 	conf |= FIELD_PREP(MESON_MX_SDIO_CONF_CMD_ARGUMENT_BITS_MASK, 39);
707 	conf |= FIELD_PREP(MESON_MX_SDIO_CONF_M_ENDIAN_MASK, 0x3);
708 	conf |= FIELD_PREP(MESON_MX_SDIO_CONF_WRITE_NWR_MASK, 0x2);
709 	conf |= FIELD_PREP(MESON_MX_SDIO_CONF_WRITE_CRC_OK_STATUS_MASK, 0x2);
710 	writel(conf, host->base + MESON_MX_SDIO_CONF);
711 
712 	meson_mx_mmc_soft_reset(host);
713 
714 	ret = meson_mx_mmc_add_host(host);
715 	if (ret)
716 		goto error_disable_clks;
717 
718 	return 0;
719 
720 error_disable_clks:
721 	clk_disable_unprepare(host->cfg_div_clk);
722 error_disable_core_clk:
723 	clk_disable_unprepare(host->core_clk);
724 error_free_mmc:
725 	mmc_free_host(mmc);
726 error_unregister_slot_pdev:
727 	of_platform_device_destroy(&slot_pdev->dev, NULL);
728 	return ret;
729 }
730 
731 static void meson_mx_mmc_remove(struct platform_device *pdev)
732 {
733 	struct meson_mx_mmc_host *host = platform_get_drvdata(pdev);
734 	struct device *slot_dev = mmc_dev(host->mmc);
735 
736 	del_timer_sync(&host->cmd_timeout);
737 
738 	mmc_remove_host(host->mmc);
739 
740 	of_platform_device_destroy(slot_dev, NULL);
741 
742 	clk_disable_unprepare(host->cfg_div_clk);
743 	clk_disable_unprepare(host->core_clk);
744 
745 	mmc_free_host(host->mmc);
746 }
747 
748 static const struct of_device_id meson_mx_mmc_of_match[] = {
749 	{ .compatible = "amlogic,meson8-sdio", },
750 	{ .compatible = "amlogic,meson8b-sdio", },
751 	{ /* sentinel */ }
752 };
753 MODULE_DEVICE_TABLE(of, meson_mx_mmc_of_match);
754 
755 static struct platform_driver meson_mx_mmc_driver = {
756 	.probe   = meson_mx_mmc_probe,
757 	.remove_new = meson_mx_mmc_remove,
758 	.driver  = {
759 		.name = "meson-mx-sdio",
760 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
761 		.of_match_table = of_match_ptr(meson_mx_mmc_of_match),
762 	},
763 };
764 
765 module_platform_driver(meson_mx_mmc_driver);
766 
767 MODULE_DESCRIPTION("Meson6, Meson8 and Meson8b SDIO/MMC Host Driver");
768 MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
769 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
770 MODULE_LICENSE("GPL v2");
771