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1 /*
2  * Amlogic SD/eMMC driver for the GX/S905 family SoCs
3  *
4  * Copyright (c) 2016 BayLibre, SAS.
5  * Author: Kevin Hilman <khilman@baylibre.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of version 2 of the GNU General Public License as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  * The full GNU General Public License is included in this distribution
19  * in the file called COPYING.
20  */
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/delay.h>
25 #include <linux/device.h>
26 #include <linux/of_device.h>
27 #include <linux/platform_device.h>
28 #include <linux/ioport.h>
29 #include <linux/spinlock.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/mmc/host.h>
32 #include <linux/mmc/mmc.h>
33 #include <linux/mmc/sdio.h>
34 #include <linux/mmc/slot-gpio.h>
35 #include <linux/io.h>
36 #include <linux/clk.h>
37 #include <linux/clk-provider.h>
38 #include <linux/regulator/consumer.h>
39 #include <linux/interrupt.h>
40 #include <linux/bitfield.h>
41 
42 #define DRIVER_NAME "meson-gx-mmc"
43 
44 #define SD_EMMC_CLOCK 0x0
45 #define   CLK_DIV_MASK GENMASK(5, 0)
46 #define   CLK_SRC_MASK GENMASK(7, 6)
47 #define   CLK_CORE_PHASE_MASK GENMASK(9, 8)
48 #define   CLK_TX_PHASE_MASK GENMASK(11, 10)
49 #define   CLK_RX_PHASE_MASK GENMASK(13, 12)
50 #define   CLK_TX_DELAY_MASK GENMASK(19, 16)
51 #define   CLK_RX_DELAY_MASK GENMASK(23, 20)
52 #define   CLK_DELAY_STEP_PS 200
53 #define   CLK_PHASE_STEP 30
54 #define   CLK_PHASE_POINT_NUM (360 / CLK_PHASE_STEP)
55 #define   CLK_ALWAYS_ON BIT(24)
56 
57 #define SD_EMMC_DELAY 0x4
58 #define SD_EMMC_ADJUST 0x8
59 #define SD_EMMC_CALOUT 0x10
60 #define SD_EMMC_START 0x40
61 #define   START_DESC_INIT BIT(0)
62 #define   START_DESC_BUSY BIT(1)
63 #define   START_DESC_ADDR_MASK GENMASK(31, 2)
64 
65 #define SD_EMMC_CFG 0x44
66 #define   CFG_BUS_WIDTH_MASK GENMASK(1, 0)
67 #define   CFG_BUS_WIDTH_1 0x0
68 #define   CFG_BUS_WIDTH_4 0x1
69 #define   CFG_BUS_WIDTH_8 0x2
70 #define   CFG_DDR BIT(2)
71 #define   CFG_BLK_LEN_MASK GENMASK(7, 4)
72 #define   CFG_RESP_TIMEOUT_MASK GENMASK(11, 8)
73 #define   CFG_RC_CC_MASK GENMASK(15, 12)
74 #define   CFG_STOP_CLOCK BIT(22)
75 #define   CFG_CLK_ALWAYS_ON BIT(18)
76 #define   CFG_CHK_DS BIT(20)
77 #define   CFG_AUTO_CLK BIT(23)
78 #define   CFG_ERR_ABORT BIT(27)
79 
80 #define SD_EMMC_STATUS 0x48
81 #define   STATUS_BUSY BIT(31)
82 #define   STATUS_DESC_BUSY BIT(30)
83 #define   STATUS_DATI GENMASK(23, 16)
84 
85 #define SD_EMMC_IRQ_EN 0x4c
86 #define   IRQ_RXD_ERR_MASK GENMASK(7, 0)
87 #define   IRQ_TXD_ERR BIT(8)
88 #define   IRQ_DESC_ERR BIT(9)
89 #define   IRQ_RESP_ERR BIT(10)
90 #define   IRQ_CRC_ERR \
91 	(IRQ_RXD_ERR_MASK | IRQ_TXD_ERR | IRQ_DESC_ERR | IRQ_RESP_ERR)
92 #define   IRQ_RESP_TIMEOUT BIT(11)
93 #define   IRQ_DESC_TIMEOUT BIT(12)
94 #define   IRQ_TIMEOUTS \
95 	(IRQ_RESP_TIMEOUT | IRQ_DESC_TIMEOUT)
96 #define   IRQ_END_OF_CHAIN BIT(13)
97 #define   IRQ_RESP_STATUS BIT(14)
98 #define   IRQ_SDIO BIT(15)
99 #define   IRQ_EN_MASK \
100 	(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN | IRQ_RESP_STATUS |\
101 	 IRQ_SDIO)
102 
103 #define SD_EMMC_CMD_CFG 0x50
104 #define SD_EMMC_CMD_ARG 0x54
105 #define SD_EMMC_CMD_DAT 0x58
106 #define SD_EMMC_CMD_RSP 0x5c
107 #define SD_EMMC_CMD_RSP1 0x60
108 #define SD_EMMC_CMD_RSP2 0x64
109 #define SD_EMMC_CMD_RSP3 0x68
110 
111 #define SD_EMMC_RXD 0x94
112 #define SD_EMMC_TXD 0x94
113 #define SD_EMMC_LAST_REG SD_EMMC_TXD
114 
115 #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
116 #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
117 #define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */
118 #define SD_EMMC_CMD_TIMEOUT_DATA 4096 /* in ms */
119 #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
120 #define SD_EMMC_DESC_BUF_LEN PAGE_SIZE
121 
122 #define SD_EMMC_PRE_REQ_DONE BIT(0)
123 #define SD_EMMC_DESC_CHAIN_MODE BIT(1)
124 
125 #define MUX_CLK_NUM_PARENTS 2
126 
127 struct sd_emmc_desc {
128 	u32 cmd_cfg;
129 	u32 cmd_arg;
130 	u32 cmd_data;
131 	u32 cmd_resp;
132 };
133 
134 struct meson_host {
135 	struct	device		*dev;
136 	struct	mmc_host	*mmc;
137 	struct	mmc_command	*cmd;
138 
139 	spinlock_t lock;
140 	void __iomem *regs;
141 	struct clk *core_clk;
142 	struct clk *mmc_clk;
143 	struct clk *rx_clk;
144 	struct clk *tx_clk;
145 	unsigned long req_rate;
146 
147 	struct pinctrl *pinctrl;
148 	struct pinctrl_state *pins_default;
149 	struct pinctrl_state *pins_clk_gate;
150 
151 	unsigned int bounce_buf_size;
152 	void *bounce_buf;
153 	dma_addr_t bounce_dma_addr;
154 	struct sd_emmc_desc *descs;
155 	dma_addr_t descs_dma_addr;
156 
157 	bool vqmmc_enabled;
158 };
159 
160 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
161 #define CMD_CFG_BLOCK_MODE BIT(9)
162 #define CMD_CFG_R1B BIT(10)
163 #define CMD_CFG_END_OF_CHAIN BIT(11)
164 #define CMD_CFG_TIMEOUT_MASK GENMASK(15, 12)
165 #define CMD_CFG_NO_RESP BIT(16)
166 #define CMD_CFG_NO_CMD BIT(17)
167 #define CMD_CFG_DATA_IO BIT(18)
168 #define CMD_CFG_DATA_WR BIT(19)
169 #define CMD_CFG_RESP_NOCRC BIT(20)
170 #define CMD_CFG_RESP_128 BIT(21)
171 #define CMD_CFG_RESP_NUM BIT(22)
172 #define CMD_CFG_DATA_NUM BIT(23)
173 #define CMD_CFG_CMD_INDEX_MASK GENMASK(29, 24)
174 #define CMD_CFG_ERROR BIT(30)
175 #define CMD_CFG_OWNER BIT(31)
176 
177 #define CMD_DATA_MASK GENMASK(31, 2)
178 #define CMD_DATA_BIG_ENDIAN BIT(1)
179 #define CMD_DATA_SRAM BIT(0)
180 #define CMD_RESP_MASK GENMASK(31, 1)
181 #define CMD_RESP_SRAM BIT(0)
182 
183 struct meson_mmc_phase {
184 	struct clk_hw hw;
185 	void __iomem *reg;
186 	unsigned long phase_mask;
187 	unsigned long delay_mask;
188 	unsigned int delay_step_ps;
189 };
190 
191 #define to_meson_mmc_phase(_hw) container_of(_hw, struct meson_mmc_phase, hw)
192 
meson_mmc_clk_get_phase(struct clk_hw * hw)193 static int meson_mmc_clk_get_phase(struct clk_hw *hw)
194 {
195 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
196 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
197 	unsigned long period_ps, p, d;
198 		int degrees;
199 	u32 val;
200 
201 	val = readl(mmc->reg);
202 	p = (val & mmc->phase_mask) >> __ffs(mmc->phase_mask);
203 	degrees = p * 360 / phase_num;
204 
205 	if (mmc->delay_mask) {
206 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
207 					 clk_get_rate(hw->clk));
208 		d = (val & mmc->delay_mask) >> __ffs(mmc->delay_mask);
209 		degrees += d * mmc->delay_step_ps * 360 / period_ps;
210 		degrees %= 360;
211 	}
212 
213 	return degrees;
214 }
215 
meson_mmc_apply_phase_delay(struct meson_mmc_phase * mmc,unsigned int phase,unsigned int delay)216 static void meson_mmc_apply_phase_delay(struct meson_mmc_phase *mmc,
217 					unsigned int phase,
218 					unsigned int delay)
219 {
220 	u32 val;
221 
222 	val = readl(mmc->reg);
223 	val &= ~mmc->phase_mask;
224 	val |= phase << __ffs(mmc->phase_mask);
225 
226 	if (mmc->delay_mask) {
227 		val &= ~mmc->delay_mask;
228 		val |= delay << __ffs(mmc->delay_mask);
229 	}
230 
231 	writel(val, mmc->reg);
232 }
233 
meson_mmc_clk_set_phase(struct clk_hw * hw,int degrees)234 static int meson_mmc_clk_set_phase(struct clk_hw *hw, int degrees)
235 {
236 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
237 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
238 	unsigned long period_ps, d = 0, r;
239 	uint64_t p;
240 
241 	p = degrees % 360;
242 
243 	if (!mmc->delay_mask) {
244 		p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
245 	} else {
246 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
247 					 clk_get_rate(hw->clk));
248 
249 		/* First compute the phase index (p), the remainder (r) is the
250 		 * part we'll try to acheive using the delays (d).
251 		 */
252 		r = do_div(p, 360 / phase_num);
253 		d = DIV_ROUND_CLOSEST(r * period_ps,
254 				      360 * mmc->delay_step_ps);
255 		d = min(d, mmc->delay_mask >> __ffs(mmc->delay_mask));
256 	}
257 
258 	meson_mmc_apply_phase_delay(mmc, p, d);
259 	return 0;
260 }
261 
262 static const struct clk_ops meson_mmc_clk_phase_ops = {
263 	.get_phase = meson_mmc_clk_get_phase,
264 	.set_phase = meson_mmc_clk_set_phase,
265 };
266 
meson_mmc_get_timeout_msecs(struct mmc_data * data)267 static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
268 {
269 	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
270 
271 	if (!timeout)
272 		return SD_EMMC_CMD_TIMEOUT_DATA;
273 
274 	timeout = roundup_pow_of_two(timeout);
275 
276 	return min(timeout, 32768U); /* max. 2^15 ms */
277 }
278 
meson_mmc_get_next_command(struct mmc_command * cmd)279 static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
280 {
281 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
282 		return cmd->mrq->cmd;
283 	else if (mmc_op_multi(cmd->opcode) &&
284 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
285 		return cmd->mrq->stop;
286 	else
287 		return NULL;
288 }
289 
meson_mmc_get_transfer_mode(struct mmc_host * mmc,struct mmc_request * mrq)290 static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
291 					struct mmc_request *mrq)
292 {
293 	struct mmc_data *data = mrq->data;
294 	struct scatterlist *sg;
295 	int i;
296 	bool use_desc_chain_mode = true;
297 
298 	/*
299 	 * Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been
300 	 * reported. For some strange reason this occurs in descriptor
301 	 * chain mode only. So let's fall back to bounce buffer mode
302 	 * for command SD_IO_RW_EXTENDED.
303 	 */
304 	if (mrq->cmd->opcode == SD_IO_RW_EXTENDED)
305 		return;
306 
307 	for_each_sg(data->sg, sg, data->sg_len, i)
308 		/* check for 8 byte alignment */
309 		if (sg->offset & 7) {
310 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
311 			use_desc_chain_mode = false;
312 			break;
313 		}
314 
315 	if (use_desc_chain_mode)
316 		data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
317 }
318 
meson_mmc_desc_chain_mode(const struct mmc_data * data)319 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
320 {
321 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
322 }
323 
meson_mmc_bounce_buf_read(const struct mmc_data * data)324 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
325 {
326 	return data && data->flags & MMC_DATA_READ &&
327 	       !meson_mmc_desc_chain_mode(data);
328 }
329 
meson_mmc_pre_req(struct mmc_host * mmc,struct mmc_request * mrq)330 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
331 {
332 	struct mmc_data *data = mrq->data;
333 
334 	if (!data)
335 		return;
336 
337 	meson_mmc_get_transfer_mode(mmc, mrq);
338 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
339 
340 	if (!meson_mmc_desc_chain_mode(data))
341 		return;
342 
343 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
344                                    mmc_get_dma_dir(data));
345 	if (!data->sg_count)
346 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
347 }
348 
meson_mmc_post_req(struct mmc_host * mmc,struct mmc_request * mrq,int err)349 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
350 			       int err)
351 {
352 	struct mmc_data *data = mrq->data;
353 
354 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
355 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
356 			     mmc_get_dma_dir(data));
357 }
358 
meson_mmc_timing_is_ddr(struct mmc_ios * ios)359 static bool meson_mmc_timing_is_ddr(struct mmc_ios *ios)
360 {
361 	if (ios->timing == MMC_TIMING_MMC_DDR52 ||
362 	    ios->timing == MMC_TIMING_UHS_DDR50 ||
363 	    ios->timing == MMC_TIMING_MMC_HS400)
364 		return true;
365 
366 	return false;
367 }
368 
369 /*
370  * Gating the clock on this controller is tricky.  It seems the mmc clock
371  * is also used by the controller.  It may crash during some operation if the
372  * clock is stopped.  The safest thing to do, whenever possible, is to keep
373  * clock running at stop it at the pad using the pinmux.
374  */
meson_mmc_clk_gate(struct meson_host * host)375 static void meson_mmc_clk_gate(struct meson_host *host)
376 {
377 	u32 cfg;
378 
379 	if (host->pins_clk_gate) {
380 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
381 	} else {
382 		/*
383 		 * If the pinmux is not provided - default to the classic and
384 		 * unsafe method
385 		 */
386 		cfg = readl(host->regs + SD_EMMC_CFG);
387 		cfg |= CFG_STOP_CLOCK;
388 		writel(cfg, host->regs + SD_EMMC_CFG);
389 	}
390 }
391 
meson_mmc_clk_ungate(struct meson_host * host)392 static void meson_mmc_clk_ungate(struct meson_host *host)
393 {
394 	u32 cfg;
395 
396 	if (host->pins_clk_gate)
397 		pinctrl_select_state(host->pinctrl, host->pins_default);
398 
399 	/* Make sure the clock is not stopped in the controller */
400 	cfg = readl(host->regs + SD_EMMC_CFG);
401 	cfg &= ~CFG_STOP_CLOCK;
402 	writel(cfg, host->regs + SD_EMMC_CFG);
403 }
404 
meson_mmc_clk_set(struct meson_host * host,struct mmc_ios * ios)405 static int meson_mmc_clk_set(struct meson_host *host, struct mmc_ios *ios)
406 {
407 	struct mmc_host *mmc = host->mmc;
408 	unsigned long rate = ios->clock;
409 	int ret;
410 	u32 cfg;
411 
412 	/* DDR modes require higher module clock */
413 	if (meson_mmc_timing_is_ddr(ios))
414 		rate <<= 1;
415 
416 	/* Same request - bail-out */
417 	if (host->req_rate == rate)
418 		return 0;
419 
420 	/* stop clock */
421 	meson_mmc_clk_gate(host);
422 	host->req_rate = 0;
423 
424 	if (!rate) {
425 		mmc->actual_clock = 0;
426 		/* return with clock being stopped */
427 		return 0;
428 	}
429 
430 	/* Stop the clock during rate change to avoid glitches */
431 	cfg = readl(host->regs + SD_EMMC_CFG);
432 	cfg |= CFG_STOP_CLOCK;
433 	writel(cfg, host->regs + SD_EMMC_CFG);
434 
435 	ret = clk_set_rate(host->mmc_clk, rate);
436 	if (ret) {
437 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
438 			rate, ret);
439 		return ret;
440 	}
441 
442 	host->req_rate = rate;
443 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
444 
445 	/* We should report the real output frequency of the controller */
446 	if (meson_mmc_timing_is_ddr(ios))
447 		mmc->actual_clock >>= 1;
448 
449 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
450 	if (ios->clock != mmc->actual_clock)
451 		dev_dbg(host->dev, "requested rate was %u\n", ios->clock);
452 
453 	/* (re)start clock */
454 	meson_mmc_clk_ungate(host);
455 
456 	return 0;
457 }
458 
459 /*
460  * The SD/eMMC IP block has an internal mux and divider used for
461  * generating the MMC clock.  Use the clock framework to create and
462  * manage these clocks.
463  */
meson_mmc_clk_init(struct meson_host * host)464 static int meson_mmc_clk_init(struct meson_host *host)
465 {
466 	struct clk_init_data init;
467 	struct clk_mux *mux;
468 	struct clk_divider *div;
469 	struct meson_mmc_phase *core, *tx, *rx;
470 	struct clk *clk;
471 	char clk_name[32];
472 	int i, ret = 0;
473 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
474 	const char *clk_parent[1];
475 	u32 clk_reg;
476 
477 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
478 	clk_reg = 0;
479 	clk_reg |= CLK_ALWAYS_ON;
480 	clk_reg |= CLK_DIV_MASK;
481 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
482 
483 	/* get the mux parents */
484 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
485 		struct clk *clk;
486 		char name[16];
487 
488 		snprintf(name, sizeof(name), "clkin%d", i);
489 		clk = devm_clk_get(host->dev, name);
490 		if (IS_ERR(clk)) {
491 			if (clk != ERR_PTR(-EPROBE_DEFER))
492 				dev_err(host->dev, "Missing clock %s\n", name);
493 			return PTR_ERR(clk);
494 		}
495 
496 		mux_parent_names[i] = __clk_get_name(clk);
497 	}
498 
499 	/* create the mux */
500 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
501 	if (!mux)
502 		return -ENOMEM;
503 
504 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
505 	init.name = clk_name;
506 	init.ops = &clk_mux_ops;
507 	init.flags = 0;
508 	init.parent_names = mux_parent_names;
509 	init.num_parents = MUX_CLK_NUM_PARENTS;
510 
511 	mux->reg = host->regs + SD_EMMC_CLOCK;
512 	mux->shift = __ffs(CLK_SRC_MASK);
513 	mux->mask = CLK_SRC_MASK >> mux->shift;
514 	mux->hw.init = &init;
515 
516 	clk = devm_clk_register(host->dev, &mux->hw);
517 	if (WARN_ON(IS_ERR(clk)))
518 		return PTR_ERR(clk);
519 
520 	/* create the divider */
521 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
522 	if (!div)
523 		return -ENOMEM;
524 
525 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
526 	init.name = clk_name;
527 	init.ops = &clk_divider_ops;
528 	init.flags = CLK_SET_RATE_PARENT;
529 	clk_parent[0] = __clk_get_name(clk);
530 	init.parent_names = clk_parent;
531 	init.num_parents = 1;
532 
533 	div->reg = host->regs + SD_EMMC_CLOCK;
534 	div->shift = __ffs(CLK_DIV_MASK);
535 	div->width = __builtin_popcountl(CLK_DIV_MASK);
536 	div->hw.init = &init;
537 	div->flags = CLK_DIVIDER_ONE_BASED;
538 
539 	clk = devm_clk_register(host->dev, &div->hw);
540 	if (WARN_ON(IS_ERR(clk)))
541 		return PTR_ERR(clk);
542 
543 	/* create the mmc core clock */
544 	core = devm_kzalloc(host->dev, sizeof(*core), GFP_KERNEL);
545 	if (!core)
546 		return -ENOMEM;
547 
548 	snprintf(clk_name, sizeof(clk_name), "%s#core", dev_name(host->dev));
549 	init.name = clk_name;
550 	init.ops = &meson_mmc_clk_phase_ops;
551 	init.flags = CLK_SET_RATE_PARENT;
552 	clk_parent[0] = __clk_get_name(clk);
553 	init.parent_names = clk_parent;
554 	init.num_parents = 1;
555 
556 	core->reg = host->regs + SD_EMMC_CLOCK;
557 	core->phase_mask = CLK_CORE_PHASE_MASK;
558 	core->hw.init = &init;
559 
560 	host->mmc_clk = devm_clk_register(host->dev, &core->hw);
561 	if (WARN_ON(PTR_ERR_OR_ZERO(host->mmc_clk)))
562 		return PTR_ERR(host->mmc_clk);
563 
564 	/* create the mmc tx clock */
565 	tx = devm_kzalloc(host->dev, sizeof(*tx), GFP_KERNEL);
566 	if (!tx)
567 		return -ENOMEM;
568 
569 	snprintf(clk_name, sizeof(clk_name), "%s#tx", dev_name(host->dev));
570 	init.name = clk_name;
571 	init.ops = &meson_mmc_clk_phase_ops;
572 	init.flags = 0;
573 	clk_parent[0] = __clk_get_name(host->mmc_clk);
574 	init.parent_names = clk_parent;
575 	init.num_parents = 1;
576 
577 	tx->reg = host->regs + SD_EMMC_CLOCK;
578 	tx->phase_mask = CLK_TX_PHASE_MASK;
579 	tx->delay_mask = CLK_TX_DELAY_MASK;
580 	tx->delay_step_ps = CLK_DELAY_STEP_PS;
581 	tx->hw.init = &init;
582 
583 	host->tx_clk = devm_clk_register(host->dev, &tx->hw);
584 	if (WARN_ON(PTR_ERR_OR_ZERO(host->tx_clk)))
585 		return PTR_ERR(host->tx_clk);
586 
587 	/* create the mmc rx clock */
588 	rx = devm_kzalloc(host->dev, sizeof(*rx), GFP_KERNEL);
589 	if (!rx)
590 		return -ENOMEM;
591 
592 	snprintf(clk_name, sizeof(clk_name), "%s#rx", dev_name(host->dev));
593 	init.name = clk_name;
594 	init.ops = &meson_mmc_clk_phase_ops;
595 	init.flags = 0;
596 	clk_parent[0] = __clk_get_name(host->mmc_clk);
597 	init.parent_names = clk_parent;
598 	init.num_parents = 1;
599 
600 	rx->reg = host->regs + SD_EMMC_CLOCK;
601 	rx->phase_mask = CLK_RX_PHASE_MASK;
602 	rx->delay_mask = CLK_RX_DELAY_MASK;
603 	rx->delay_step_ps = CLK_DELAY_STEP_PS;
604 	rx->hw.init = &init;
605 
606 	host->rx_clk = devm_clk_register(host->dev, &rx->hw);
607 	if (WARN_ON(PTR_ERR_OR_ZERO(host->rx_clk)))
608 		return PTR_ERR(host->rx_clk);
609 
610 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
611 	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
612 	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
613 	if (ret)
614 		return ret;
615 
616 	/*
617 	 * Set phases : These values are mostly the datasheet recommended ones
618 	 * except for the Tx phase. Datasheet recommends 180 but some cards
619 	 * fail at initialisation with it. 270 works just fine, it fixes these
620 	 * initialisation issues and enable eMMC DDR52 mode.
621 	 */
622 	clk_set_phase(host->mmc_clk, 180);
623 	clk_set_phase(host->tx_clk, 270);
624 	clk_set_phase(host->rx_clk, 0);
625 
626 	return clk_prepare_enable(host->mmc_clk);
627 }
628 
meson_mmc_shift_map(unsigned long * map,unsigned long shift)629 static void meson_mmc_shift_map(unsigned long *map, unsigned long shift)
630 {
631 	DECLARE_BITMAP(left, CLK_PHASE_POINT_NUM);
632 	DECLARE_BITMAP(right, CLK_PHASE_POINT_NUM);
633 
634 	/*
635 	 * shift the bitmap right and reintroduce the dropped bits on the left
636 	 * of the bitmap
637 	 */
638 	bitmap_shift_right(right, map, shift, CLK_PHASE_POINT_NUM);
639 	bitmap_shift_left(left, map, CLK_PHASE_POINT_NUM - shift,
640 			  CLK_PHASE_POINT_NUM);
641 	bitmap_or(map, left, right, CLK_PHASE_POINT_NUM);
642 }
643 
meson_mmc_find_next_region(unsigned long * map,unsigned long * start,unsigned long * stop)644 static void meson_mmc_find_next_region(unsigned long *map,
645 				       unsigned long *start,
646 				       unsigned long *stop)
647 {
648 	*start = find_next_bit(map, CLK_PHASE_POINT_NUM, *start);
649 	*stop = find_next_zero_bit(map, CLK_PHASE_POINT_NUM, *start);
650 }
651 
meson_mmc_find_tuning_point(unsigned long * test)652 static int meson_mmc_find_tuning_point(unsigned long *test)
653 {
654 	unsigned long shift, stop, offset = 0, start = 0, size = 0;
655 
656 	/* Get the all good/all bad situation out the way */
657 	if (bitmap_full(test, CLK_PHASE_POINT_NUM))
658 		return 0; /* All points are good so point 0 will do */
659 	else if (bitmap_empty(test, CLK_PHASE_POINT_NUM))
660 		return -EIO; /* No successful tuning point */
661 
662 	/*
663 	 * Now we know there is a least one region find. Make sure it does
664 	 * not wrap by the shifting the bitmap if necessary
665 	 */
666 	shift = find_first_zero_bit(test, CLK_PHASE_POINT_NUM);
667 	if (shift != 0)
668 		meson_mmc_shift_map(test, shift);
669 
670 	while (start < CLK_PHASE_POINT_NUM) {
671 		meson_mmc_find_next_region(test, &start, &stop);
672 
673 		if ((stop - start) > size) {
674 			offset = start;
675 			size = stop - start;
676 		}
677 
678 		start = stop;
679 	}
680 
681 	/* Get the center point of the region */
682 	offset += (size / 2);
683 
684 	/* Shift the result back */
685 	offset = (offset + shift) % CLK_PHASE_POINT_NUM;
686 
687 	return offset;
688 }
689 
meson_mmc_clk_phase_tuning(struct mmc_host * mmc,u32 opcode,struct clk * clk)690 static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode,
691 				      struct clk *clk)
692 {
693 	int point, ret;
694 	DECLARE_BITMAP(test, CLK_PHASE_POINT_NUM);
695 
696 	dev_dbg(mmc_dev(mmc), "%s phase/delay tunning...\n",
697 		__clk_get_name(clk));
698 	bitmap_zero(test, CLK_PHASE_POINT_NUM);
699 
700 	/* Explore tuning points */
701 	for (point = 0; point < CLK_PHASE_POINT_NUM; point++) {
702 		clk_set_phase(clk, point * CLK_PHASE_STEP);
703 		ret = mmc_send_tuning(mmc, opcode, NULL);
704 		if (!ret)
705 			set_bit(point, test);
706 	}
707 
708 	/* Find the optimal tuning point and apply it */
709 	point = meson_mmc_find_tuning_point(test);
710 	if (point < 0)
711 		return point; /* tuning failed */
712 
713 	clk_set_phase(clk, point * CLK_PHASE_STEP);
714 	dev_dbg(mmc_dev(mmc), "success with phase: %d\n",
715 		clk_get_phase(clk));
716 	return 0;
717 }
718 
meson_mmc_execute_tuning(struct mmc_host * mmc,u32 opcode)719 static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
720 {
721 	struct meson_host *host = mmc_priv(mmc);
722 
723 	return meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
724 }
725 
meson_mmc_set_ios(struct mmc_host * mmc,struct mmc_ios * ios)726 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
727 {
728 	struct meson_host *host = mmc_priv(mmc);
729 	u32 bus_width, val;
730 	int err;
731 
732 	/*
733 	 * GPIO regulator, only controls switching between 1v8 and
734 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
735 	 */
736 	switch (ios->power_mode) {
737 	case MMC_POWER_OFF:
738 		if (!IS_ERR(mmc->supply.vmmc))
739 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
740 
741 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
742 			regulator_disable(mmc->supply.vqmmc);
743 			host->vqmmc_enabled = false;
744 		}
745 
746 		break;
747 
748 	case MMC_POWER_UP:
749 		if (!IS_ERR(mmc->supply.vmmc))
750 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
751 
752 		/* Reset rx phase */
753 		clk_set_phase(host->rx_clk, 0);
754 
755 		break;
756 
757 	case MMC_POWER_ON:
758 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
759 			int ret = regulator_enable(mmc->supply.vqmmc);
760 
761 			if (ret < 0)
762 				dev_err(host->dev,
763 					"failed to enable vqmmc regulator\n");
764 			else
765 				host->vqmmc_enabled = true;
766 		}
767 
768 		break;
769 	}
770 
771 	/* Bus width */
772 	switch (ios->bus_width) {
773 	case MMC_BUS_WIDTH_1:
774 		bus_width = CFG_BUS_WIDTH_1;
775 		break;
776 	case MMC_BUS_WIDTH_4:
777 		bus_width = CFG_BUS_WIDTH_4;
778 		break;
779 	case MMC_BUS_WIDTH_8:
780 		bus_width = CFG_BUS_WIDTH_8;
781 		break;
782 	default:
783 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
784 			ios->bus_width);
785 		bus_width = CFG_BUS_WIDTH_4;
786 	}
787 
788 	val = readl(host->regs + SD_EMMC_CFG);
789 	val &= ~CFG_BUS_WIDTH_MASK;
790 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
791 
792 	val &= ~CFG_DDR;
793 	if (meson_mmc_timing_is_ddr(ios))
794 		val |= CFG_DDR;
795 
796 	val &= ~CFG_CHK_DS;
797 	if (ios->timing == MMC_TIMING_MMC_HS400)
798 		val |= CFG_CHK_DS;
799 
800 	err = meson_mmc_clk_set(host, ios);
801 	if (err)
802 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
803 
804 	writel(val, host->regs + SD_EMMC_CFG);
805 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
806 }
807 
meson_mmc_request_done(struct mmc_host * mmc,struct mmc_request * mrq)808 static void meson_mmc_request_done(struct mmc_host *mmc,
809 				   struct mmc_request *mrq)
810 {
811 	struct meson_host *host = mmc_priv(mmc);
812 
813 	host->cmd = NULL;
814 	mmc_request_done(host->mmc, mrq);
815 }
816 
meson_mmc_set_blksz(struct mmc_host * mmc,unsigned int blksz)817 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
818 {
819 	struct meson_host *host = mmc_priv(mmc);
820 	u32 cfg, blksz_old;
821 
822 	cfg = readl(host->regs + SD_EMMC_CFG);
823 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
824 
825 	if (!is_power_of_2(blksz))
826 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
827 
828 	blksz = ilog2(blksz);
829 
830 	/* check if block-size matches, if not update */
831 	if (blksz == blksz_old)
832 		return;
833 
834 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
835 		blksz_old, blksz);
836 
837 	cfg &= ~CFG_BLK_LEN_MASK;
838 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
839 	writel(cfg, host->regs + SD_EMMC_CFG);
840 }
841 
meson_mmc_set_response_bits(struct mmc_command * cmd,u32 * cmd_cfg)842 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
843 {
844 	if (cmd->flags & MMC_RSP_PRESENT) {
845 		if (cmd->flags & MMC_RSP_136)
846 			*cmd_cfg |= CMD_CFG_RESP_128;
847 		*cmd_cfg |= CMD_CFG_RESP_NUM;
848 
849 		if (!(cmd->flags & MMC_RSP_CRC))
850 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
851 
852 		if (cmd->flags & MMC_RSP_BUSY)
853 			*cmd_cfg |= CMD_CFG_R1B;
854 	} else {
855 		*cmd_cfg |= CMD_CFG_NO_RESP;
856 	}
857 }
858 
meson_mmc_desc_chain_transfer(struct mmc_host * mmc,u32 cmd_cfg)859 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
860 {
861 	struct meson_host *host = mmc_priv(mmc);
862 	struct sd_emmc_desc *desc = host->descs;
863 	struct mmc_data *data = host->cmd->data;
864 	struct scatterlist *sg;
865 	u32 start;
866 	int i;
867 
868 	if (data->flags & MMC_DATA_WRITE)
869 		cmd_cfg |= CMD_CFG_DATA_WR;
870 
871 	if (data->blocks > 1) {
872 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
873 		meson_mmc_set_blksz(mmc, data->blksz);
874 	}
875 
876 	for_each_sg(data->sg, sg, data->sg_count, i) {
877 		unsigned int len = sg_dma_len(sg);
878 
879 		if (data->blocks > 1)
880 			len /= data->blksz;
881 
882 		desc[i].cmd_cfg = cmd_cfg;
883 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
884 		if (i > 0)
885 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
886 		desc[i].cmd_arg = host->cmd->arg;
887 		desc[i].cmd_resp = 0;
888 		desc[i].cmd_data = sg_dma_address(sg);
889 	}
890 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
891 
892 	dma_wmb(); /* ensure descriptor is written before kicked */
893 	start = host->descs_dma_addr | START_DESC_BUSY;
894 	writel(start, host->regs + SD_EMMC_START);
895 }
896 
meson_mmc_start_cmd(struct mmc_host * mmc,struct mmc_command * cmd)897 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
898 {
899 	struct meson_host *host = mmc_priv(mmc);
900 	struct mmc_data *data = cmd->data;
901 	u32 cmd_cfg = 0, cmd_data = 0;
902 	unsigned int xfer_bytes = 0;
903 
904 	/* Setup descriptors */
905 	dma_rmb();
906 
907 	host->cmd = cmd;
908 
909 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
910 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
911 	cmd_cfg |= CMD_CFG_ERROR; /* stop in case of error */
912 
913 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
914 
915 	/* data? */
916 	if (data) {
917 		data->bytes_xfered = 0;
918 		cmd_cfg |= CMD_CFG_DATA_IO;
919 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
920 				      ilog2(meson_mmc_get_timeout_msecs(data)));
921 
922 		if (meson_mmc_desc_chain_mode(data)) {
923 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
924 			return;
925 		}
926 
927 		if (data->blocks > 1) {
928 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
929 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
930 					      data->blocks);
931 			meson_mmc_set_blksz(mmc, data->blksz);
932 		} else {
933 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
934 		}
935 
936 		xfer_bytes = data->blksz * data->blocks;
937 		if (data->flags & MMC_DATA_WRITE) {
938 			cmd_cfg |= CMD_CFG_DATA_WR;
939 			WARN_ON(xfer_bytes > host->bounce_buf_size);
940 			sg_copy_to_buffer(data->sg, data->sg_len,
941 					  host->bounce_buf, xfer_bytes);
942 			dma_wmb();
943 		}
944 
945 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
946 	} else {
947 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
948 				      ilog2(SD_EMMC_CMD_TIMEOUT));
949 	}
950 
951 	/* Last descriptor */
952 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
953 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
954 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
955 	writel(0, host->regs + SD_EMMC_CMD_RSP);
956 	wmb(); /* ensure descriptor is written before kicked */
957 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
958 }
959 
meson_mmc_request(struct mmc_host * mmc,struct mmc_request * mrq)960 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
961 {
962 	struct meson_host *host = mmc_priv(mmc);
963 	bool needs_pre_post_req = mrq->data &&
964 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
965 
966 	if (needs_pre_post_req) {
967 		meson_mmc_get_transfer_mode(mmc, mrq);
968 		if (!meson_mmc_desc_chain_mode(mrq->data))
969 			needs_pre_post_req = false;
970 	}
971 
972 	if (needs_pre_post_req)
973 		meson_mmc_pre_req(mmc, mrq);
974 
975 	/* Stop execution */
976 	writel(0, host->regs + SD_EMMC_START);
977 
978 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
979 
980 	if (needs_pre_post_req)
981 		meson_mmc_post_req(mmc, mrq, 0);
982 }
983 
meson_mmc_read_resp(struct mmc_host * mmc,struct mmc_command * cmd)984 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
985 {
986 	struct meson_host *host = mmc_priv(mmc);
987 
988 	if (cmd->flags & MMC_RSP_136) {
989 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
990 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
991 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
992 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
993 	} else if (cmd->flags & MMC_RSP_PRESENT) {
994 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
995 	}
996 }
997 
meson_mmc_irq(int irq,void * dev_id)998 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
999 {
1000 	struct meson_host *host = dev_id;
1001 	struct mmc_command *cmd;
1002 	struct mmc_data *data;
1003 	u32 irq_en, status, raw_status;
1004 	irqreturn_t ret = IRQ_NONE;
1005 
1006 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
1007 	raw_status = readl(host->regs + SD_EMMC_STATUS);
1008 	status = raw_status & irq_en;
1009 
1010 	if (!status) {
1011 		dev_dbg(host->dev,
1012 			"Unexpected IRQ! irq_en 0x%08x - status 0x%08x\n",
1013 			 irq_en, raw_status);
1014 		return IRQ_NONE;
1015 	}
1016 
1017 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
1018 		return IRQ_NONE;
1019 
1020 	spin_lock(&host->lock);
1021 
1022 	cmd = host->cmd;
1023 	data = cmd->data;
1024 	cmd->error = 0;
1025 	if (status & IRQ_CRC_ERR) {
1026 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
1027 		cmd->error = -EILSEQ;
1028 		ret = IRQ_WAKE_THREAD;
1029 		goto out;
1030 	}
1031 
1032 	if (status & IRQ_TIMEOUTS) {
1033 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
1034 		cmd->error = -ETIMEDOUT;
1035 		ret = IRQ_WAKE_THREAD;
1036 		goto out;
1037 	}
1038 
1039 	meson_mmc_read_resp(host->mmc, cmd);
1040 
1041 	if (status & IRQ_SDIO) {
1042 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
1043 		ret = IRQ_HANDLED;
1044 	}
1045 
1046 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
1047 		if (data && !cmd->error)
1048 			data->bytes_xfered = data->blksz * data->blocks;
1049 		if (meson_mmc_bounce_buf_read(data) ||
1050 		    meson_mmc_get_next_command(cmd))
1051 			ret = IRQ_WAKE_THREAD;
1052 		else
1053 			ret = IRQ_HANDLED;
1054 	}
1055 
1056 out:
1057 	/* ack all enabled interrupts */
1058 	writel(irq_en, host->regs + SD_EMMC_STATUS);
1059 
1060 	if (cmd->error) {
1061 		/* Stop desc in case of errors */
1062 		u32 start = readl(host->regs + SD_EMMC_START);
1063 
1064 		start &= ~START_DESC_BUSY;
1065 		writel(start, host->regs + SD_EMMC_START);
1066 	}
1067 
1068 	if (ret == IRQ_HANDLED)
1069 		meson_mmc_request_done(host->mmc, cmd->mrq);
1070 
1071 	spin_unlock(&host->lock);
1072 	return ret;
1073 }
1074 
meson_mmc_wait_desc_stop(struct meson_host * host)1075 static int meson_mmc_wait_desc_stop(struct meson_host *host)
1076 {
1077 	int loop;
1078 	u32 status;
1079 
1080 	/*
1081 	 * It may sometimes take a while for it to actually halt. Here, we
1082 	 * are giving it 5ms to comply
1083 	 *
1084 	 * If we don't confirm the descriptor is stopped, it might raise new
1085 	 * IRQs after we have called mmc_request_done() which is bad.
1086 	 */
1087 	for (loop = 50; loop; loop--) {
1088 		status = readl(host->regs + SD_EMMC_STATUS);
1089 		if (status & (STATUS_BUSY | STATUS_DESC_BUSY))
1090 			udelay(100);
1091 		else
1092 			break;
1093 	}
1094 
1095 	if (status & (STATUS_BUSY | STATUS_DESC_BUSY)) {
1096 		dev_err(host->dev, "Timed out waiting for host to stop\n");
1097 		return -ETIMEDOUT;
1098 	}
1099 
1100 	return 0;
1101 }
1102 
meson_mmc_irq_thread(int irq,void * dev_id)1103 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
1104 {
1105 	struct meson_host *host = dev_id;
1106 	struct mmc_command *next_cmd, *cmd = host->cmd;
1107 	struct mmc_data *data;
1108 	unsigned int xfer_bytes;
1109 
1110 	if (WARN_ON(!cmd))
1111 		return IRQ_NONE;
1112 
1113 	if (cmd->error) {
1114 		meson_mmc_wait_desc_stop(host);
1115 		meson_mmc_request_done(host->mmc, cmd->mrq);
1116 
1117 		return IRQ_HANDLED;
1118 	}
1119 
1120 	data = cmd->data;
1121 	if (meson_mmc_bounce_buf_read(data)) {
1122 		xfer_bytes = data->blksz * data->blocks;
1123 		WARN_ON(xfer_bytes > host->bounce_buf_size);
1124 		sg_copy_from_buffer(data->sg, data->sg_len,
1125 				    host->bounce_buf, xfer_bytes);
1126 	}
1127 
1128 	next_cmd = meson_mmc_get_next_command(cmd);
1129 	if (next_cmd)
1130 		meson_mmc_start_cmd(host->mmc, next_cmd);
1131 	else
1132 		meson_mmc_request_done(host->mmc, cmd->mrq);
1133 
1134 	return IRQ_HANDLED;
1135 }
1136 
1137 /*
1138  * NOTE: we only need this until the GPIO/pinctrl driver can handle
1139  * interrupts.  For now, the MMC core will use this for polling.
1140  */
meson_mmc_get_cd(struct mmc_host * mmc)1141 static int meson_mmc_get_cd(struct mmc_host *mmc)
1142 {
1143 	int status = mmc_gpio_get_cd(mmc);
1144 
1145 	if (status == -ENOSYS)
1146 		return 1; /* assume present */
1147 
1148 	return status;
1149 }
1150 
meson_mmc_cfg_init(struct meson_host * host)1151 static void meson_mmc_cfg_init(struct meson_host *host)
1152 {
1153 	u32 cfg = 0;
1154 
1155 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
1156 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
1157 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
1158 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
1159 
1160 	/* abort chain on R/W errors */
1161 	cfg |= CFG_ERR_ABORT;
1162 
1163 	writel(cfg, host->regs + SD_EMMC_CFG);
1164 }
1165 
meson_mmc_card_busy(struct mmc_host * mmc)1166 static int meson_mmc_card_busy(struct mmc_host *mmc)
1167 {
1168 	struct meson_host *host = mmc_priv(mmc);
1169 	u32 regval;
1170 
1171 	regval = readl(host->regs + SD_EMMC_STATUS);
1172 
1173 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1174 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1175 }
1176 
meson_mmc_voltage_switch(struct mmc_host * mmc,struct mmc_ios * ios)1177 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1178 {
1179 	/* vqmmc regulator is available */
1180 	if (!IS_ERR(mmc->supply.vqmmc)) {
1181 		/*
1182 		 * The usual amlogic setup uses a GPIO to switch from one
1183 		 * regulator to the other. While the voltage ramp up is
1184 		 * pretty fast, care must be taken when switching from 3.3v
1185 		 * to 1.8v. Please make sure the regulator framework is aware
1186 		 * of your own regulator constraints
1187 		 */
1188 		return mmc_regulator_set_vqmmc(mmc, ios);
1189 	}
1190 
1191 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1192 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1193 		return 0;
1194 
1195 	return -EINVAL;
1196 }
1197 
1198 static const struct mmc_host_ops meson_mmc_ops = {
1199 	.request	= meson_mmc_request,
1200 	.set_ios	= meson_mmc_set_ios,
1201 	.get_cd         = meson_mmc_get_cd,
1202 	.pre_req	= meson_mmc_pre_req,
1203 	.post_req	= meson_mmc_post_req,
1204 	.execute_tuning = meson_mmc_execute_tuning,
1205 	.card_busy	= meson_mmc_card_busy,
1206 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1207 };
1208 
meson_mmc_probe(struct platform_device * pdev)1209 static int meson_mmc_probe(struct platform_device *pdev)
1210 {
1211 	struct resource *res;
1212 	struct meson_host *host;
1213 	struct mmc_host *mmc;
1214 	int ret, irq;
1215 
1216 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1217 	if (!mmc)
1218 		return -ENOMEM;
1219 	host = mmc_priv(mmc);
1220 	host->mmc = mmc;
1221 	host->dev = &pdev->dev;
1222 	dev_set_drvdata(&pdev->dev, host);
1223 
1224 	spin_lock_init(&host->lock);
1225 
1226 	/* Get regulators and the supported OCR mask */
1227 	host->vqmmc_enabled = false;
1228 	ret = mmc_regulator_get_supply(mmc);
1229 	if (ret == -EPROBE_DEFER)
1230 		goto free_host;
1231 
1232 	ret = mmc_of_parse(mmc);
1233 	if (ret) {
1234 		if (ret != -EPROBE_DEFER)
1235 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1236 		goto free_host;
1237 	}
1238 
1239 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1240 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1241 	if (IS_ERR(host->regs)) {
1242 		ret = PTR_ERR(host->regs);
1243 		goto free_host;
1244 	}
1245 
1246 	irq = platform_get_irq(pdev, 0);
1247 	if (!irq) {
1248 		dev_err(&pdev->dev, "failed to get interrupt resource.\n");
1249 		ret = -EINVAL;
1250 		goto free_host;
1251 	}
1252 
1253 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1254 	if (IS_ERR(host->pinctrl)) {
1255 		ret = PTR_ERR(host->pinctrl);
1256 		goto free_host;
1257 	}
1258 
1259 	host->pins_default = pinctrl_lookup_state(host->pinctrl,
1260 						  PINCTRL_STATE_DEFAULT);
1261 	if (IS_ERR(host->pins_default)) {
1262 		ret = PTR_ERR(host->pins_default);
1263 		goto free_host;
1264 	}
1265 
1266 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1267 						   "clk-gate");
1268 	if (IS_ERR(host->pins_clk_gate)) {
1269 		dev_warn(&pdev->dev,
1270 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1271 		host->pins_clk_gate = NULL;
1272 	}
1273 
1274 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1275 	if (IS_ERR(host->core_clk)) {
1276 		ret = PTR_ERR(host->core_clk);
1277 		goto free_host;
1278 	}
1279 
1280 	ret = clk_prepare_enable(host->core_clk);
1281 	if (ret)
1282 		goto free_host;
1283 
1284 	ret = meson_mmc_clk_init(host);
1285 	if (ret)
1286 		goto err_core_clk;
1287 
1288 	/* set config to sane default */
1289 	meson_mmc_cfg_init(host);
1290 
1291 	/* Stop execution */
1292 	writel(0, host->regs + SD_EMMC_START);
1293 
1294 	/* clear, ack and enable interrupts */
1295 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1296 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1297 	       host->regs + SD_EMMC_STATUS);
1298 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1299 	       host->regs + SD_EMMC_IRQ_EN);
1300 
1301 	ret = devm_request_threaded_irq(&pdev->dev, irq, meson_mmc_irq,
1302 					meson_mmc_irq_thread, IRQF_SHARED,
1303 					NULL, host);
1304 	if (ret)
1305 		goto err_init_clk;
1306 
1307 	mmc->caps |= MMC_CAP_CMD23;
1308 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1309 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1310 	mmc->max_segs = SD_EMMC_DESC_BUF_LEN / sizeof(struct sd_emmc_desc);
1311 	mmc->max_seg_size = mmc->max_req_size;
1312 
1313 	/* data bounce buffer */
1314 	host->bounce_buf_size = mmc->max_req_size;
1315 	host->bounce_buf =
1316 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
1317 				   &host->bounce_dma_addr, GFP_KERNEL);
1318 	if (host->bounce_buf == NULL) {
1319 		dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1320 		ret = -ENOMEM;
1321 		goto err_init_clk;
1322 	}
1323 
1324 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1325 		      &host->descs_dma_addr, GFP_KERNEL);
1326 	if (!host->descs) {
1327 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1328 		ret = -ENOMEM;
1329 		goto err_bounce_buf;
1330 	}
1331 
1332 	mmc->ops = &meson_mmc_ops;
1333 	mmc_add_host(mmc);
1334 
1335 	return 0;
1336 
1337 err_bounce_buf:
1338 	dma_free_coherent(host->dev, host->bounce_buf_size,
1339 			  host->bounce_buf, host->bounce_dma_addr);
1340 err_init_clk:
1341 	clk_disable_unprepare(host->mmc_clk);
1342 err_core_clk:
1343 	clk_disable_unprepare(host->core_clk);
1344 free_host:
1345 	mmc_free_host(mmc);
1346 	return ret;
1347 }
1348 
meson_mmc_remove(struct platform_device * pdev)1349 static int meson_mmc_remove(struct platform_device *pdev)
1350 {
1351 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1352 
1353 	mmc_remove_host(host->mmc);
1354 
1355 	/* disable interrupts */
1356 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1357 
1358 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1359 			  host->descs, host->descs_dma_addr);
1360 	dma_free_coherent(host->dev, host->bounce_buf_size,
1361 			  host->bounce_buf, host->bounce_dma_addr);
1362 
1363 	clk_disable_unprepare(host->mmc_clk);
1364 	clk_disable_unprepare(host->core_clk);
1365 
1366 	mmc_free_host(host->mmc);
1367 	return 0;
1368 }
1369 
1370 static const struct of_device_id meson_mmc_of_match[] = {
1371 	{ .compatible = "amlogic,meson-gx-mmc", },
1372 	{ .compatible = "amlogic,meson-gxbb-mmc", },
1373 	{ .compatible = "amlogic,meson-gxl-mmc", },
1374 	{ .compatible = "amlogic,meson-gxm-mmc", },
1375 	{}
1376 };
1377 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1378 
1379 static struct platform_driver meson_mmc_driver = {
1380 	.probe		= meson_mmc_probe,
1381 	.remove		= meson_mmc_remove,
1382 	.driver		= {
1383 		.name = DRIVER_NAME,
1384 		.of_match_table = of_match_ptr(meson_mmc_of_match),
1385 	},
1386 };
1387 
1388 module_platform_driver(meson_mmc_driver);
1389 
1390 MODULE_DESCRIPTION("Amlogic S905*/GX* SD/eMMC driver");
1391 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1392 MODULE_LICENSE("GPL v2");
1393