xref: /openbmc/linux/drivers/spi/spi-geni-qcom.c (revision 3c8c1539)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
3 
4 #include <linux/clk.h>
5 #include <linux/interrupt.h>
6 #include <linux/io.h>
7 #include <linux/log2.h>
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/pm_opp.h>
11 #include <linux/pm_runtime.h>
12 #include <linux/qcom-geni-se.h>
13 #include <linux/spi/spi.h>
14 #include <linux/spinlock.h>
15 
16 /* SPI SE specific registers and respective register fields */
17 #define SE_SPI_CPHA		0x224
18 #define CPHA			BIT(0)
19 
20 #define SE_SPI_LOOPBACK		0x22c
21 #define LOOPBACK_ENABLE		0x1
22 #define NORMAL_MODE		0x0
23 #define LOOPBACK_MSK		GENMASK(1, 0)
24 
25 #define SE_SPI_CPOL		0x230
26 #define CPOL			BIT(2)
27 
28 #define SE_SPI_DEMUX_OUTPUT_INV	0x24c
29 #define CS_DEMUX_OUTPUT_INV_MSK	GENMASK(3, 0)
30 
31 #define SE_SPI_DEMUX_SEL	0x250
32 #define CS_DEMUX_OUTPUT_SEL	GENMASK(3, 0)
33 
34 #define SE_SPI_TRANS_CFG	0x25c
35 #define CS_TOGGLE		BIT(0)
36 
37 #define SE_SPI_WORD_LEN		0x268
38 #define WORD_LEN_MSK		GENMASK(9, 0)
39 #define MIN_WORD_LEN		4
40 
41 #define SE_SPI_TX_TRANS_LEN	0x26c
42 #define SE_SPI_RX_TRANS_LEN	0x270
43 #define TRANS_LEN_MSK		GENMASK(23, 0)
44 
45 #define SE_SPI_PRE_POST_CMD_DLY	0x274
46 
47 #define SE_SPI_DELAY_COUNTERS	0x278
48 #define SPI_INTER_WORDS_DELAY_MSK	GENMASK(9, 0)
49 #define SPI_CS_CLK_DELAY_MSK		GENMASK(19, 10)
50 #define SPI_CS_CLK_DELAY_SHFT		10
51 
52 /* M_CMD OP codes for SPI */
53 #define SPI_TX_ONLY		1
54 #define SPI_RX_ONLY		2
55 #define SPI_TX_RX		7
56 #define SPI_CS_ASSERT		8
57 #define SPI_CS_DEASSERT		9
58 #define SPI_SCK_ONLY		10
59 /* M_CMD params for SPI */
60 #define SPI_PRE_CMD_DELAY	BIT(0)
61 #define TIMESTAMP_BEFORE	BIT(1)
62 #define FRAGMENTATION		BIT(2)
63 #define TIMESTAMP_AFTER		BIT(3)
64 #define POST_CMD_DELAY		BIT(4)
65 
66 struct spi_geni_master {
67 	struct geni_se se;
68 	struct device *dev;
69 	u32 tx_fifo_depth;
70 	u32 fifo_width_bits;
71 	u32 tx_wm;
72 	u32 last_mode;
73 	unsigned long cur_speed_hz;
74 	unsigned long cur_sclk_hz;
75 	unsigned int cur_bits_per_word;
76 	unsigned int tx_rem_bytes;
77 	unsigned int rx_rem_bytes;
78 	const struct spi_transfer *cur_xfer;
79 	struct completion cs_done;
80 	struct completion cancel_done;
81 	struct completion abort_done;
82 	unsigned int oversampling;
83 	spinlock_t lock;
84 	int irq;
85 	bool cs_flag;
86 	bool abort_failed;
87 };
88 
89 static int get_spi_clk_cfg(unsigned int speed_hz,
90 			struct spi_geni_master *mas,
91 			unsigned int *clk_idx,
92 			unsigned int *clk_div)
93 {
94 	unsigned long sclk_freq;
95 	unsigned int actual_hz;
96 	int ret;
97 
98 	ret = geni_se_clk_freq_match(&mas->se,
99 				speed_hz * mas->oversampling,
100 				clk_idx, &sclk_freq, false);
101 	if (ret) {
102 		dev_err(mas->dev, "Failed(%d) to find src clk for %dHz\n",
103 							ret, speed_hz);
104 		return ret;
105 	}
106 
107 	*clk_div = DIV_ROUND_UP(sclk_freq, mas->oversampling * speed_hz);
108 	actual_hz = sclk_freq / (mas->oversampling * *clk_div);
109 
110 	dev_dbg(mas->dev, "req %u=>%u sclk %lu, idx %d, div %d\n", speed_hz,
111 				actual_hz, sclk_freq, *clk_idx, *clk_div);
112 	ret = dev_pm_opp_set_rate(mas->dev, sclk_freq);
113 	if (ret)
114 		dev_err(mas->dev, "dev_pm_opp_set_rate failed %d\n", ret);
115 	else
116 		mas->cur_sclk_hz = sclk_freq;
117 
118 	return ret;
119 }
120 
121 static void handle_fifo_timeout(struct spi_master *spi,
122 				struct spi_message *msg)
123 {
124 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
125 	unsigned long time_left;
126 	struct geni_se *se = &mas->se;
127 
128 	spin_lock_irq(&mas->lock);
129 	reinit_completion(&mas->cancel_done);
130 	writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
131 	mas->cur_xfer = NULL;
132 	geni_se_cancel_m_cmd(se);
133 	spin_unlock_irq(&mas->lock);
134 
135 	time_left = wait_for_completion_timeout(&mas->cancel_done, HZ);
136 	if (time_left)
137 		return;
138 
139 	spin_lock_irq(&mas->lock);
140 	reinit_completion(&mas->abort_done);
141 	geni_se_abort_m_cmd(se);
142 	spin_unlock_irq(&mas->lock);
143 
144 	time_left = wait_for_completion_timeout(&mas->abort_done, HZ);
145 	if (!time_left) {
146 		dev_err(mas->dev, "Failed to cancel/abort m_cmd\n");
147 
148 		/*
149 		 * No need for a lock since SPI core has a lock and we never
150 		 * access this from an interrupt.
151 		 */
152 		mas->abort_failed = true;
153 	}
154 }
155 
156 static bool spi_geni_is_abort_still_pending(struct spi_geni_master *mas)
157 {
158 	struct geni_se *se = &mas->se;
159 	u32 m_irq, m_irq_en;
160 
161 	if (!mas->abort_failed)
162 		return false;
163 
164 	/*
165 	 * The only known case where a transfer times out and then a cancel
166 	 * times out then an abort times out is if something is blocking our
167 	 * interrupt handler from running.  Avoid starting any new transfers
168 	 * until that sorts itself out.
169 	 */
170 	spin_lock_irq(&mas->lock);
171 	m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
172 	m_irq_en = readl(se->base + SE_GENI_M_IRQ_EN);
173 	spin_unlock_irq(&mas->lock);
174 
175 	if (m_irq & m_irq_en) {
176 		dev_err(mas->dev, "Interrupts pending after abort: %#010x\n",
177 			m_irq & m_irq_en);
178 		return true;
179 	}
180 
181 	/*
182 	 * If we're here the problem resolved itself so no need to check more
183 	 * on future transfers.
184 	 */
185 	mas->abort_failed = false;
186 
187 	return false;
188 }
189 
190 static void spi_geni_set_cs(struct spi_device *slv, bool set_flag)
191 {
192 	struct spi_geni_master *mas = spi_master_get_devdata(slv->master);
193 	struct spi_master *spi = dev_get_drvdata(mas->dev);
194 	struct geni_se *se = &mas->se;
195 	unsigned long time_left;
196 
197 	if (!(slv->mode & SPI_CS_HIGH))
198 		set_flag = !set_flag;
199 
200 	if (set_flag == mas->cs_flag)
201 		return;
202 
203 	pm_runtime_get_sync(mas->dev);
204 
205 	if (spi_geni_is_abort_still_pending(mas)) {
206 		dev_err(mas->dev, "Can't set chip select\n");
207 		goto exit;
208 	}
209 
210 	spin_lock_irq(&mas->lock);
211 	if (mas->cur_xfer) {
212 		dev_err(mas->dev, "Can't set CS when prev xfer running\n");
213 		spin_unlock_irq(&mas->lock);
214 		goto exit;
215 	}
216 
217 	mas->cs_flag = set_flag;
218 	reinit_completion(&mas->cs_done);
219 	if (set_flag)
220 		geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0);
221 	else
222 		geni_se_setup_m_cmd(se, SPI_CS_DEASSERT, 0);
223 	spin_unlock_irq(&mas->lock);
224 
225 	time_left = wait_for_completion_timeout(&mas->cs_done, HZ);
226 	if (!time_left) {
227 		dev_warn(mas->dev, "Timeout setting chip select\n");
228 		handle_fifo_timeout(spi, NULL);
229 	}
230 
231 exit:
232 	pm_runtime_put(mas->dev);
233 }
234 
235 static void spi_setup_word_len(struct spi_geni_master *mas, u16 mode,
236 					unsigned int bits_per_word)
237 {
238 	unsigned int pack_words;
239 	bool msb_first = (mode & SPI_LSB_FIRST) ? false : true;
240 	struct geni_se *se = &mas->se;
241 	u32 word_len;
242 
243 	/*
244 	 * If bits_per_word isn't a byte aligned value, set the packing to be
245 	 * 1 SPI word per FIFO word.
246 	 */
247 	if (!(mas->fifo_width_bits % bits_per_word))
248 		pack_words = mas->fifo_width_bits / bits_per_word;
249 	else
250 		pack_words = 1;
251 	geni_se_config_packing(&mas->se, bits_per_word, pack_words, msb_first,
252 								true, true);
253 	word_len = (bits_per_word - MIN_WORD_LEN) & WORD_LEN_MSK;
254 	writel(word_len, se->base + SE_SPI_WORD_LEN);
255 }
256 
257 static int geni_spi_set_clock_and_bw(struct spi_geni_master *mas,
258 					unsigned long clk_hz)
259 {
260 	u32 clk_sel, m_clk_cfg, idx, div;
261 	struct geni_se *se = &mas->se;
262 	int ret;
263 
264 	if (clk_hz == mas->cur_speed_hz)
265 		return 0;
266 
267 	ret = get_spi_clk_cfg(clk_hz, mas, &idx, &div);
268 	if (ret) {
269 		dev_err(mas->dev, "Err setting clk to %lu: %d\n", clk_hz, ret);
270 		return ret;
271 	}
272 
273 	/*
274 	 * SPI core clock gets configured with the requested frequency
275 	 * or the frequency closer to the requested frequency.
276 	 * For that reason requested frequency is stored in the
277 	 * cur_speed_hz and referred in the consecutive transfer instead
278 	 * of calling clk_get_rate() API.
279 	 */
280 	mas->cur_speed_hz = clk_hz;
281 
282 	clk_sel = idx & CLK_SEL_MSK;
283 	m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
284 	writel(clk_sel, se->base + SE_GENI_CLK_SEL);
285 	writel(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG);
286 
287 	/* Set BW quota for CPU as driver supports FIFO mode only. */
288 	se->icc_paths[CPU_TO_GENI].avg_bw = Bps_to_icc(mas->cur_speed_hz);
289 	ret = geni_icc_set_bw(se);
290 	if (ret)
291 		return ret;
292 
293 	return 0;
294 }
295 
296 static int setup_fifo_params(struct spi_device *spi_slv,
297 					struct spi_master *spi)
298 {
299 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
300 	struct geni_se *se = &mas->se;
301 	u32 loopback_cfg = 0, cpol = 0, cpha = 0, demux_output_inv = 0;
302 	u32 demux_sel;
303 
304 	if (mas->last_mode != spi_slv->mode) {
305 		if (spi_slv->mode & SPI_LOOP)
306 			loopback_cfg = LOOPBACK_ENABLE;
307 
308 		if (spi_slv->mode & SPI_CPOL)
309 			cpol = CPOL;
310 
311 		if (spi_slv->mode & SPI_CPHA)
312 			cpha = CPHA;
313 
314 		if (spi_slv->mode & SPI_CS_HIGH)
315 			demux_output_inv = BIT(spi_slv->chip_select);
316 
317 		demux_sel = spi_slv->chip_select;
318 		mas->cur_bits_per_word = spi_slv->bits_per_word;
319 
320 		spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
321 		writel(loopback_cfg, se->base + SE_SPI_LOOPBACK);
322 		writel(demux_sel, se->base + SE_SPI_DEMUX_SEL);
323 		writel(cpha, se->base + SE_SPI_CPHA);
324 		writel(cpol, se->base + SE_SPI_CPOL);
325 		writel(demux_output_inv, se->base + SE_SPI_DEMUX_OUTPUT_INV);
326 
327 		mas->last_mode = spi_slv->mode;
328 	}
329 
330 	return geni_spi_set_clock_and_bw(mas, spi_slv->max_speed_hz);
331 }
332 
333 static int spi_geni_prepare_message(struct spi_master *spi,
334 					struct spi_message *spi_msg)
335 {
336 	int ret;
337 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
338 
339 	if (spi_geni_is_abort_still_pending(mas))
340 		return -EBUSY;
341 
342 	ret = setup_fifo_params(spi_msg->spi, spi);
343 	if (ret)
344 		dev_err(mas->dev, "Couldn't select mode %d\n", ret);
345 	return ret;
346 }
347 
348 static int spi_geni_init(struct spi_geni_master *mas)
349 {
350 	struct geni_se *se = &mas->se;
351 	unsigned int proto, major, minor, ver;
352 	u32 spi_tx_cfg;
353 
354 	pm_runtime_get_sync(mas->dev);
355 
356 	proto = geni_se_read_proto(se);
357 	if (proto != GENI_SE_SPI) {
358 		dev_err(mas->dev, "Invalid proto %d\n", proto);
359 		pm_runtime_put(mas->dev);
360 		return -ENXIO;
361 	}
362 	mas->tx_fifo_depth = geni_se_get_tx_fifo_depth(se);
363 
364 	/* Width of Tx and Rx FIFO is same */
365 	mas->fifo_width_bits = geni_se_get_tx_fifo_width(se);
366 
367 	/*
368 	 * Hardware programming guide suggests to configure
369 	 * RX FIFO RFR level to fifo_depth-2.
370 	 */
371 	geni_se_init(se, mas->tx_fifo_depth - 3, mas->tx_fifo_depth - 2);
372 	/* Transmit an entire FIFO worth of data per IRQ */
373 	mas->tx_wm = 1;
374 	ver = geni_se_get_qup_hw_version(se);
375 	major = GENI_SE_VERSION_MAJOR(ver);
376 	minor = GENI_SE_VERSION_MINOR(ver);
377 
378 	if (major == 1 && minor == 0)
379 		mas->oversampling = 2;
380 	else
381 		mas->oversampling = 1;
382 
383 	geni_se_select_mode(se, GENI_SE_FIFO);
384 
385 	/* We always control CS manually */
386 	spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
387 	spi_tx_cfg &= ~CS_TOGGLE;
388 	writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
389 
390 	pm_runtime_put(mas->dev);
391 	return 0;
392 }
393 
394 static unsigned int geni_byte_per_fifo_word(struct spi_geni_master *mas)
395 {
396 	/*
397 	 * Calculate how many bytes we'll put in each FIFO word.  If the
398 	 * transfer words don't pack cleanly into a FIFO word we'll just put
399 	 * one transfer word in each FIFO word.  If they do pack we'll pack 'em.
400 	 */
401 	if (mas->fifo_width_bits % mas->cur_bits_per_word)
402 		return roundup_pow_of_two(DIV_ROUND_UP(mas->cur_bits_per_word,
403 						       BITS_PER_BYTE));
404 
405 	return mas->fifo_width_bits / BITS_PER_BYTE;
406 }
407 
408 static bool geni_spi_handle_tx(struct spi_geni_master *mas)
409 {
410 	struct geni_se *se = &mas->se;
411 	unsigned int max_bytes;
412 	const u8 *tx_buf;
413 	unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
414 	unsigned int i = 0;
415 
416 	/* Stop the watermark IRQ if nothing to send */
417 	if (!mas->cur_xfer) {
418 		writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
419 		return false;
420 	}
421 
422 	max_bytes = (mas->tx_fifo_depth - mas->tx_wm) * bytes_per_fifo_word;
423 	if (mas->tx_rem_bytes < max_bytes)
424 		max_bytes = mas->tx_rem_bytes;
425 
426 	tx_buf = mas->cur_xfer->tx_buf + mas->cur_xfer->len - mas->tx_rem_bytes;
427 	while (i < max_bytes) {
428 		unsigned int j;
429 		unsigned int bytes_to_write;
430 		u32 fifo_word = 0;
431 		u8 *fifo_byte = (u8 *)&fifo_word;
432 
433 		bytes_to_write = min(bytes_per_fifo_word, max_bytes - i);
434 		for (j = 0; j < bytes_to_write; j++)
435 			fifo_byte[j] = tx_buf[i++];
436 		iowrite32_rep(se->base + SE_GENI_TX_FIFOn, &fifo_word, 1);
437 	}
438 	mas->tx_rem_bytes -= max_bytes;
439 	if (!mas->tx_rem_bytes) {
440 		writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
441 		return false;
442 	}
443 	return true;
444 }
445 
446 static void geni_spi_handle_rx(struct spi_geni_master *mas)
447 {
448 	struct geni_se *se = &mas->se;
449 	u32 rx_fifo_status;
450 	unsigned int rx_bytes;
451 	unsigned int rx_last_byte_valid;
452 	u8 *rx_buf;
453 	unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
454 	unsigned int i = 0;
455 
456 	rx_fifo_status = readl(se->base + SE_GENI_RX_FIFO_STATUS);
457 	rx_bytes = (rx_fifo_status & RX_FIFO_WC_MSK) * bytes_per_fifo_word;
458 	if (rx_fifo_status & RX_LAST) {
459 		rx_last_byte_valid = rx_fifo_status & RX_LAST_BYTE_VALID_MSK;
460 		rx_last_byte_valid >>= RX_LAST_BYTE_VALID_SHFT;
461 		if (rx_last_byte_valid && rx_last_byte_valid < 4)
462 			rx_bytes -= bytes_per_fifo_word - rx_last_byte_valid;
463 	}
464 
465 	/* Clear out the FIFO and bail if nowhere to put it */
466 	if (!mas->cur_xfer) {
467 		for (i = 0; i < DIV_ROUND_UP(rx_bytes, bytes_per_fifo_word); i++)
468 			readl(se->base + SE_GENI_RX_FIFOn);
469 		return;
470 	}
471 
472 	if (mas->rx_rem_bytes < rx_bytes)
473 		rx_bytes = mas->rx_rem_bytes;
474 
475 	rx_buf = mas->cur_xfer->rx_buf + mas->cur_xfer->len - mas->rx_rem_bytes;
476 	while (i < rx_bytes) {
477 		u32 fifo_word = 0;
478 		u8 *fifo_byte = (u8 *)&fifo_word;
479 		unsigned int bytes_to_read;
480 		unsigned int j;
481 
482 		bytes_to_read = min(bytes_per_fifo_word, rx_bytes - i);
483 		ioread32_rep(se->base + SE_GENI_RX_FIFOn, &fifo_word, 1);
484 		for (j = 0; j < bytes_to_read; j++)
485 			rx_buf[i++] = fifo_byte[j];
486 	}
487 	mas->rx_rem_bytes -= rx_bytes;
488 }
489 
490 static void setup_fifo_xfer(struct spi_transfer *xfer,
491 				struct spi_geni_master *mas,
492 				u16 mode, struct spi_master *spi)
493 {
494 	u32 m_cmd = 0;
495 	u32 len;
496 	struct geni_se *se = &mas->se;
497 	int ret;
498 
499 	/*
500 	 * Ensure that our interrupt handler isn't still running from some
501 	 * prior command before we start messing with the hardware behind
502 	 * its back.  We don't need to _keep_ the lock here since we're only
503 	 * worried about racing with out interrupt handler.  The SPI core
504 	 * already handles making sure that we're not trying to do two
505 	 * transfers at once or setting a chip select and doing a transfer
506 	 * concurrently.
507 	 *
508 	 * NOTE: we actually _can't_ hold the lock here because possibly we
509 	 * might call clk_set_rate() which needs to be able to sleep.
510 	 */
511 	spin_lock_irq(&mas->lock);
512 	spin_unlock_irq(&mas->lock);
513 
514 	if (xfer->bits_per_word != mas->cur_bits_per_word) {
515 		spi_setup_word_len(mas, mode, xfer->bits_per_word);
516 		mas->cur_bits_per_word = xfer->bits_per_word;
517 	}
518 
519 	/* Speed and bits per word can be overridden per transfer */
520 	ret = geni_spi_set_clock_and_bw(mas, xfer->speed_hz);
521 	if (ret)
522 		return;
523 
524 	mas->tx_rem_bytes = 0;
525 	mas->rx_rem_bytes = 0;
526 
527 	if (!(mas->cur_bits_per_word % MIN_WORD_LEN))
528 		len = xfer->len * BITS_PER_BYTE / mas->cur_bits_per_word;
529 	else
530 		len = xfer->len / (mas->cur_bits_per_word / BITS_PER_BYTE + 1);
531 	len &= TRANS_LEN_MSK;
532 
533 	mas->cur_xfer = xfer;
534 	if (xfer->tx_buf) {
535 		m_cmd |= SPI_TX_ONLY;
536 		mas->tx_rem_bytes = xfer->len;
537 		writel(len, se->base + SE_SPI_TX_TRANS_LEN);
538 	}
539 
540 	if (xfer->rx_buf) {
541 		m_cmd |= SPI_RX_ONLY;
542 		writel(len, se->base + SE_SPI_RX_TRANS_LEN);
543 		mas->rx_rem_bytes = xfer->len;
544 	}
545 
546 	/*
547 	 * Lock around right before we start the transfer since our
548 	 * interrupt could come in at any time now.
549 	 */
550 	spin_lock_irq(&mas->lock);
551 	geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
552 	if (m_cmd & SPI_TX_ONLY) {
553 		if (geni_spi_handle_tx(mas))
554 			writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
555 	}
556 	spin_unlock_irq(&mas->lock);
557 }
558 
559 static int spi_geni_transfer_one(struct spi_master *spi,
560 				struct spi_device *slv,
561 				struct spi_transfer *xfer)
562 {
563 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
564 
565 	if (spi_geni_is_abort_still_pending(mas))
566 		return -EBUSY;
567 
568 	/* Terminate and return success for 0 byte length transfer */
569 	if (!xfer->len)
570 		return 0;
571 
572 	setup_fifo_xfer(xfer, mas, slv->mode, spi);
573 	return 1;
574 }
575 
576 static irqreturn_t geni_spi_isr(int irq, void *data)
577 {
578 	struct spi_master *spi = data;
579 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
580 	struct geni_se *se = &mas->se;
581 	u32 m_irq;
582 
583 	m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
584 	if (!m_irq)
585 		return IRQ_NONE;
586 
587 	if (m_irq & (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN |
588 		     M_RX_FIFO_RD_ERR_EN | M_RX_FIFO_WR_ERR_EN |
589 		     M_TX_FIFO_RD_ERR_EN | M_TX_FIFO_WR_ERR_EN))
590 		dev_warn(mas->dev, "Unexpected IRQ err status %#010x\n", m_irq);
591 
592 	spin_lock(&mas->lock);
593 
594 	if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
595 		geni_spi_handle_rx(mas);
596 
597 	if (m_irq & M_TX_FIFO_WATERMARK_EN)
598 		geni_spi_handle_tx(mas);
599 
600 	if (m_irq & M_CMD_DONE_EN) {
601 		if (mas->cur_xfer) {
602 			spi_finalize_current_transfer(spi);
603 			mas->cur_xfer = NULL;
604 			/*
605 			 * If this happens, then a CMD_DONE came before all the
606 			 * Tx buffer bytes were sent out. This is unusual, log
607 			 * this condition and disable the WM interrupt to
608 			 * prevent the system from stalling due an interrupt
609 			 * storm.
610 			 *
611 			 * If this happens when all Rx bytes haven't been
612 			 * received, log the condition. The only known time
613 			 * this can happen is if bits_per_word != 8 and some
614 			 * registers that expect xfer lengths in num spi_words
615 			 * weren't written correctly.
616 			 */
617 			if (mas->tx_rem_bytes) {
618 				writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
619 				dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n",
620 					mas->tx_rem_bytes, mas->cur_bits_per_word);
621 			}
622 			if (mas->rx_rem_bytes)
623 				dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n",
624 					mas->rx_rem_bytes, mas->cur_bits_per_word);
625 		} else {
626 			complete(&mas->cs_done);
627 		}
628 	}
629 
630 	if (m_irq & M_CMD_CANCEL_EN)
631 		complete(&mas->cancel_done);
632 	if (m_irq & M_CMD_ABORT_EN)
633 		complete(&mas->abort_done);
634 
635 	/*
636 	 * It's safe or a good idea to Ack all of our interrupts at the end
637 	 * of the function. Specifically:
638 	 * - M_CMD_DONE_EN / M_RX_FIFO_LAST_EN: Edge triggered interrupts and
639 	 *   clearing Acks. Clearing at the end relies on nobody else having
640 	 *   started a new transfer yet or else we could be clearing _their_
641 	 *   done bit, but everyone grabs the spinlock before starting a new
642 	 *   transfer.
643 	 * - M_RX_FIFO_WATERMARK_EN / M_TX_FIFO_WATERMARK_EN: These appear
644 	 *   to be "latched level" interrupts so it's important to clear them
645 	 *   _after_ you've handled the condition and always safe to do so
646 	 *   since they'll re-assert if they're still happening.
647 	 */
648 	writel(m_irq, se->base + SE_GENI_M_IRQ_CLEAR);
649 
650 	spin_unlock(&mas->lock);
651 
652 	return IRQ_HANDLED;
653 }
654 
655 static int spi_geni_probe(struct platform_device *pdev)
656 {
657 	int ret, irq;
658 	struct spi_master *spi;
659 	struct spi_geni_master *mas;
660 	void __iomem *base;
661 	struct clk *clk;
662 	struct device *dev = &pdev->dev;
663 
664 	irq = platform_get_irq(pdev, 0);
665 	if (irq < 0)
666 		return irq;
667 
668 	base = devm_platform_ioremap_resource(pdev, 0);
669 	if (IS_ERR(base))
670 		return PTR_ERR(base);
671 
672 	clk = devm_clk_get(dev, "se");
673 	if (IS_ERR(clk))
674 		return PTR_ERR(clk);
675 
676 	spi = devm_spi_alloc_master(dev, sizeof(*mas));
677 	if (!spi)
678 		return -ENOMEM;
679 
680 	platform_set_drvdata(pdev, spi);
681 	mas = spi_master_get_devdata(spi);
682 	mas->irq = irq;
683 	mas->dev = dev;
684 	mas->se.dev = dev;
685 	mas->se.wrapper = dev_get_drvdata(dev->parent);
686 	mas->se.base = base;
687 	mas->se.clk = clk;
688 
689 	ret = devm_pm_opp_set_clkname(&pdev->dev, "se");
690 	if (ret)
691 		return ret;
692 	/* OPP table is optional */
693 	ret = devm_pm_opp_of_add_table(&pdev->dev);
694 	if (ret && ret != -ENODEV) {
695 		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
696 		return ret;
697 	}
698 
699 	spi->bus_num = -1;
700 	spi->dev.of_node = dev->of_node;
701 	spi->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_CS_HIGH;
702 	spi->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
703 	spi->num_chipselect = 4;
704 	spi->max_speed_hz = 50000000;
705 	spi->prepare_message = spi_geni_prepare_message;
706 	spi->transfer_one = spi_geni_transfer_one;
707 	spi->auto_runtime_pm = true;
708 	spi->handle_err = handle_fifo_timeout;
709 	spi->set_cs = spi_geni_set_cs;
710 	spi->use_gpio_descriptors = true;
711 
712 	init_completion(&mas->cs_done);
713 	init_completion(&mas->cancel_done);
714 	init_completion(&mas->abort_done);
715 	spin_lock_init(&mas->lock);
716 	pm_runtime_use_autosuspend(&pdev->dev);
717 	pm_runtime_set_autosuspend_delay(&pdev->dev, 250);
718 	pm_runtime_enable(dev);
719 
720 	ret = geni_icc_get(&mas->se, NULL);
721 	if (ret)
722 		goto spi_geni_probe_runtime_disable;
723 	/* Set the bus quota to a reasonable value for register access */
724 	mas->se.icc_paths[GENI_TO_CORE].avg_bw = Bps_to_icc(CORE_2X_50_MHZ);
725 	mas->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
726 
727 	ret = geni_icc_set_bw(&mas->se);
728 	if (ret)
729 		goto spi_geni_probe_runtime_disable;
730 
731 	ret = spi_geni_init(mas);
732 	if (ret)
733 		goto spi_geni_probe_runtime_disable;
734 
735 	ret = request_irq(mas->irq, geni_spi_isr, 0, dev_name(dev), spi);
736 	if (ret)
737 		goto spi_geni_probe_runtime_disable;
738 
739 	ret = spi_register_master(spi);
740 	if (ret)
741 		goto spi_geni_probe_free_irq;
742 
743 	return 0;
744 spi_geni_probe_free_irq:
745 	free_irq(mas->irq, spi);
746 spi_geni_probe_runtime_disable:
747 	pm_runtime_disable(dev);
748 	return ret;
749 }
750 
751 static int spi_geni_remove(struct platform_device *pdev)
752 {
753 	struct spi_master *spi = platform_get_drvdata(pdev);
754 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
755 
756 	/* Unregister _before_ disabling pm_runtime() so we stop transfers */
757 	spi_unregister_master(spi);
758 
759 	free_irq(mas->irq, spi);
760 	pm_runtime_disable(&pdev->dev);
761 	return 0;
762 }
763 
764 static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
765 {
766 	struct spi_master *spi = dev_get_drvdata(dev);
767 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
768 	int ret;
769 
770 	/* Drop the performance state vote */
771 	dev_pm_opp_set_rate(dev, 0);
772 
773 	ret = geni_se_resources_off(&mas->se);
774 	if (ret)
775 		return ret;
776 
777 	return geni_icc_disable(&mas->se);
778 }
779 
780 static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
781 {
782 	struct spi_master *spi = dev_get_drvdata(dev);
783 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
784 	int ret;
785 
786 	ret = geni_icc_enable(&mas->se);
787 	if (ret)
788 		return ret;
789 
790 	ret = geni_se_resources_on(&mas->se);
791 	if (ret)
792 		return ret;
793 
794 	return dev_pm_opp_set_rate(mas->dev, mas->cur_sclk_hz);
795 }
796 
797 static int __maybe_unused spi_geni_suspend(struct device *dev)
798 {
799 	struct spi_master *spi = dev_get_drvdata(dev);
800 	int ret;
801 
802 	ret = spi_master_suspend(spi);
803 	if (ret)
804 		return ret;
805 
806 	ret = pm_runtime_force_suspend(dev);
807 	if (ret)
808 		spi_master_resume(spi);
809 
810 	return ret;
811 }
812 
813 static int __maybe_unused spi_geni_resume(struct device *dev)
814 {
815 	struct spi_master *spi = dev_get_drvdata(dev);
816 	int ret;
817 
818 	ret = pm_runtime_force_resume(dev);
819 	if (ret)
820 		return ret;
821 
822 	ret = spi_master_resume(spi);
823 	if (ret)
824 		pm_runtime_force_suspend(dev);
825 
826 	return ret;
827 }
828 
829 static const struct dev_pm_ops spi_geni_pm_ops = {
830 	SET_RUNTIME_PM_OPS(spi_geni_runtime_suspend,
831 					spi_geni_runtime_resume, NULL)
832 	SET_SYSTEM_SLEEP_PM_OPS(spi_geni_suspend, spi_geni_resume)
833 };
834 
835 static const struct of_device_id spi_geni_dt_match[] = {
836 	{ .compatible = "qcom,geni-spi" },
837 	{}
838 };
839 MODULE_DEVICE_TABLE(of, spi_geni_dt_match);
840 
841 static struct platform_driver spi_geni_driver = {
842 	.probe  = spi_geni_probe,
843 	.remove = spi_geni_remove,
844 	.driver = {
845 		.name = "geni_spi",
846 		.pm = &spi_geni_pm_ops,
847 		.of_match_table = spi_geni_dt_match,
848 	},
849 };
850 module_platform_driver(spi_geni_driver);
851 
852 MODULE_DESCRIPTION("SPI driver for GENI based QUP cores");
853 MODULE_LICENSE("GPL v2");
854