xref: /openbmc/linux/drivers/spi/spi-geni-qcom.c (revision b285d2ae)
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 };
87 
88 static int get_spi_clk_cfg(unsigned int speed_hz,
89 			struct spi_geni_master *mas,
90 			unsigned int *clk_idx,
91 			unsigned int *clk_div)
92 {
93 	unsigned long sclk_freq;
94 	unsigned int actual_hz;
95 	int ret;
96 
97 	ret = geni_se_clk_freq_match(&mas->se,
98 				speed_hz * mas->oversampling,
99 				clk_idx, &sclk_freq, false);
100 	if (ret) {
101 		dev_err(mas->dev, "Failed(%d) to find src clk for %dHz\n",
102 							ret, speed_hz);
103 		return ret;
104 	}
105 
106 	*clk_div = DIV_ROUND_UP(sclk_freq, mas->oversampling * speed_hz);
107 	actual_hz = sclk_freq / (mas->oversampling * *clk_div);
108 
109 	dev_dbg(mas->dev, "req %u=>%u sclk %lu, idx %d, div %d\n", speed_hz,
110 				actual_hz, sclk_freq, *clk_idx, *clk_div);
111 	ret = dev_pm_opp_set_rate(mas->dev, sclk_freq);
112 	if (ret)
113 		dev_err(mas->dev, "dev_pm_opp_set_rate failed %d\n", ret);
114 	else
115 		mas->cur_sclk_hz = sclk_freq;
116 
117 	return ret;
118 }
119 
120 static void handle_fifo_timeout(struct spi_master *spi,
121 				struct spi_message *msg)
122 {
123 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
124 	unsigned long time_left;
125 	struct geni_se *se = &mas->se;
126 
127 	spin_lock_irq(&mas->lock);
128 	reinit_completion(&mas->cancel_done);
129 	writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
130 	mas->cur_xfer = NULL;
131 	geni_se_cancel_m_cmd(se);
132 	spin_unlock_irq(&mas->lock);
133 
134 	time_left = wait_for_completion_timeout(&mas->cancel_done, HZ);
135 	if (time_left)
136 		return;
137 
138 	spin_lock_irq(&mas->lock);
139 	reinit_completion(&mas->abort_done);
140 	geni_se_abort_m_cmd(se);
141 	spin_unlock_irq(&mas->lock);
142 
143 	time_left = wait_for_completion_timeout(&mas->abort_done, HZ);
144 	if (!time_left)
145 		dev_err(mas->dev, "Failed to cancel/abort m_cmd\n");
146 }
147 
148 static void spi_geni_set_cs(struct spi_device *slv, bool set_flag)
149 {
150 	struct spi_geni_master *mas = spi_master_get_devdata(slv->master);
151 	struct spi_master *spi = dev_get_drvdata(mas->dev);
152 	struct geni_se *se = &mas->se;
153 	unsigned long time_left;
154 
155 	if (!(slv->mode & SPI_CS_HIGH))
156 		set_flag = !set_flag;
157 
158 	if (set_flag == mas->cs_flag)
159 		return;
160 
161 	mas->cs_flag = set_flag;
162 
163 	pm_runtime_get_sync(mas->dev);
164 	spin_lock_irq(&mas->lock);
165 	reinit_completion(&mas->cs_done);
166 	if (set_flag)
167 		geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0);
168 	else
169 		geni_se_setup_m_cmd(se, SPI_CS_DEASSERT, 0);
170 	spin_unlock_irq(&mas->lock);
171 
172 	time_left = wait_for_completion_timeout(&mas->cs_done, HZ);
173 	if (!time_left)
174 		handle_fifo_timeout(spi, NULL);
175 
176 	pm_runtime_put(mas->dev);
177 }
178 
179 static void spi_setup_word_len(struct spi_geni_master *mas, u16 mode,
180 					unsigned int bits_per_word)
181 {
182 	unsigned int pack_words;
183 	bool msb_first = (mode & SPI_LSB_FIRST) ? false : true;
184 	struct geni_se *se = &mas->se;
185 	u32 word_len;
186 
187 	/*
188 	 * If bits_per_word isn't a byte aligned value, set the packing to be
189 	 * 1 SPI word per FIFO word.
190 	 */
191 	if (!(mas->fifo_width_bits % bits_per_word))
192 		pack_words = mas->fifo_width_bits / bits_per_word;
193 	else
194 		pack_words = 1;
195 	geni_se_config_packing(&mas->se, bits_per_word, pack_words, msb_first,
196 								true, true);
197 	word_len = (bits_per_word - MIN_WORD_LEN) & WORD_LEN_MSK;
198 	writel(word_len, se->base + SE_SPI_WORD_LEN);
199 }
200 
201 static int geni_spi_set_clock_and_bw(struct spi_geni_master *mas,
202 					unsigned long clk_hz)
203 {
204 	u32 clk_sel, m_clk_cfg, idx, div;
205 	struct geni_se *se = &mas->se;
206 	int ret;
207 
208 	if (clk_hz == mas->cur_speed_hz)
209 		return 0;
210 
211 	ret = get_spi_clk_cfg(clk_hz, mas, &idx, &div);
212 	if (ret) {
213 		dev_err(mas->dev, "Err setting clk to %lu: %d\n", clk_hz, ret);
214 		return ret;
215 	}
216 
217 	/*
218 	 * SPI core clock gets configured with the requested frequency
219 	 * or the frequency closer to the requested frequency.
220 	 * For that reason requested frequency is stored in the
221 	 * cur_speed_hz and referred in the consecutive transfer instead
222 	 * of calling clk_get_rate() API.
223 	 */
224 	mas->cur_speed_hz = clk_hz;
225 
226 	clk_sel = idx & CLK_SEL_MSK;
227 	m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
228 	writel(clk_sel, se->base + SE_GENI_CLK_SEL);
229 	writel(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG);
230 
231 	/* Set BW quota for CPU as driver supports FIFO mode only. */
232 	se->icc_paths[CPU_TO_GENI].avg_bw = Bps_to_icc(mas->cur_speed_hz);
233 	ret = geni_icc_set_bw(se);
234 	if (ret)
235 		return ret;
236 
237 	return 0;
238 }
239 
240 static int setup_fifo_params(struct spi_device *spi_slv,
241 					struct spi_master *spi)
242 {
243 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
244 	struct geni_se *se = &mas->se;
245 	u32 loopback_cfg = 0, cpol = 0, cpha = 0, demux_output_inv = 0;
246 	u32 demux_sel;
247 
248 	if (mas->last_mode != spi_slv->mode) {
249 		if (spi_slv->mode & SPI_LOOP)
250 			loopback_cfg = LOOPBACK_ENABLE;
251 
252 		if (spi_slv->mode & SPI_CPOL)
253 			cpol = CPOL;
254 
255 		if (spi_slv->mode & SPI_CPHA)
256 			cpha = CPHA;
257 
258 		if (spi_slv->mode & SPI_CS_HIGH)
259 			demux_output_inv = BIT(spi_slv->chip_select);
260 
261 		demux_sel = spi_slv->chip_select;
262 		mas->cur_bits_per_word = spi_slv->bits_per_word;
263 
264 		spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
265 		writel(loopback_cfg, se->base + SE_SPI_LOOPBACK);
266 		writel(demux_sel, se->base + SE_SPI_DEMUX_SEL);
267 		writel(cpha, se->base + SE_SPI_CPHA);
268 		writel(cpol, se->base + SE_SPI_CPOL);
269 		writel(demux_output_inv, se->base + SE_SPI_DEMUX_OUTPUT_INV);
270 
271 		mas->last_mode = spi_slv->mode;
272 	}
273 
274 	return geni_spi_set_clock_and_bw(mas, spi_slv->max_speed_hz);
275 }
276 
277 static int spi_geni_prepare_message(struct spi_master *spi,
278 					struct spi_message *spi_msg)
279 {
280 	int ret;
281 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
282 
283 	ret = setup_fifo_params(spi_msg->spi, spi);
284 	if (ret)
285 		dev_err(mas->dev, "Couldn't select mode %d\n", ret);
286 	return ret;
287 }
288 
289 static int spi_geni_init(struct spi_geni_master *mas)
290 {
291 	struct geni_se *se = &mas->se;
292 	unsigned int proto, major, minor, ver;
293 
294 	pm_runtime_get_sync(mas->dev);
295 
296 	proto = geni_se_read_proto(se);
297 	if (proto != GENI_SE_SPI) {
298 		dev_err(mas->dev, "Invalid proto %d\n", proto);
299 		pm_runtime_put(mas->dev);
300 		return -ENXIO;
301 	}
302 	mas->tx_fifo_depth = geni_se_get_tx_fifo_depth(se);
303 
304 	/* Width of Tx and Rx FIFO is same */
305 	mas->fifo_width_bits = geni_se_get_tx_fifo_width(se);
306 
307 	/*
308 	 * Hardware programming guide suggests to configure
309 	 * RX FIFO RFR level to fifo_depth-2.
310 	 */
311 	geni_se_init(se, mas->tx_fifo_depth / 2, mas->tx_fifo_depth - 2);
312 	/* Transmit an entire FIFO worth of data per IRQ */
313 	mas->tx_wm = 1;
314 	ver = geni_se_get_qup_hw_version(se);
315 	major = GENI_SE_VERSION_MAJOR(ver);
316 	minor = GENI_SE_VERSION_MINOR(ver);
317 
318 	if (major == 1 && minor == 0)
319 		mas->oversampling = 2;
320 	else
321 		mas->oversampling = 1;
322 
323 	geni_se_select_mode(se, GENI_SE_FIFO);
324 
325 	pm_runtime_put(mas->dev);
326 	return 0;
327 }
328 
329 static void setup_fifo_xfer(struct spi_transfer *xfer,
330 				struct spi_geni_master *mas,
331 				u16 mode, struct spi_master *spi)
332 {
333 	u32 m_cmd = 0;
334 	u32 spi_tx_cfg, len;
335 	struct geni_se *se = &mas->se;
336 	int ret;
337 
338 	/*
339 	 * Ensure that our interrupt handler isn't still running from some
340 	 * prior command before we start messing with the hardware behind
341 	 * its back.  We don't need to _keep_ the lock here since we're only
342 	 * worried about racing with out interrupt handler.  The SPI core
343 	 * already handles making sure that we're not trying to do two
344 	 * transfers at once or setting a chip select and doing a transfer
345 	 * concurrently.
346 	 *
347 	 * NOTE: we actually _can't_ hold the lock here because possibly we
348 	 * might call clk_set_rate() which needs to be able to sleep.
349 	 */
350 	spin_lock_irq(&mas->lock);
351 	spin_unlock_irq(&mas->lock);
352 
353 	spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
354 	if (xfer->bits_per_word != mas->cur_bits_per_word) {
355 		spi_setup_word_len(mas, mode, xfer->bits_per_word);
356 		mas->cur_bits_per_word = xfer->bits_per_word;
357 	}
358 
359 	/* Speed and bits per word can be overridden per transfer */
360 	ret = geni_spi_set_clock_and_bw(mas, xfer->speed_hz);
361 	if (ret)
362 		return;
363 
364 	mas->tx_rem_bytes = 0;
365 	mas->rx_rem_bytes = 0;
366 
367 	spi_tx_cfg &= ~CS_TOGGLE;
368 
369 	if (!(mas->cur_bits_per_word % MIN_WORD_LEN))
370 		len = xfer->len * BITS_PER_BYTE / mas->cur_bits_per_word;
371 	else
372 		len = xfer->len / (mas->cur_bits_per_word / BITS_PER_BYTE + 1);
373 	len &= TRANS_LEN_MSK;
374 
375 	mas->cur_xfer = xfer;
376 	if (xfer->tx_buf) {
377 		m_cmd |= SPI_TX_ONLY;
378 		mas->tx_rem_bytes = xfer->len;
379 		writel(len, se->base + SE_SPI_TX_TRANS_LEN);
380 	}
381 
382 	if (xfer->rx_buf) {
383 		m_cmd |= SPI_RX_ONLY;
384 		writel(len, se->base + SE_SPI_RX_TRANS_LEN);
385 		mas->rx_rem_bytes = xfer->len;
386 	}
387 	writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
388 
389 	/*
390 	 * Lock around right before we start the transfer since our
391 	 * interrupt could come in at any time now.
392 	 */
393 	spin_lock_irq(&mas->lock);
394 	geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
395 
396 	/*
397 	 * TX_WATERMARK_REG should be set after SPI configuration and
398 	 * setting up GENI SE engine, as driver starts data transfer
399 	 * for the watermark interrupt.
400 	 */
401 	if (m_cmd & SPI_TX_ONLY)
402 		writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
403 	spin_unlock_irq(&mas->lock);
404 }
405 
406 static int spi_geni_transfer_one(struct spi_master *spi,
407 				struct spi_device *slv,
408 				struct spi_transfer *xfer)
409 {
410 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
411 
412 	/* Terminate and return success for 0 byte length transfer */
413 	if (!xfer->len)
414 		return 0;
415 
416 	setup_fifo_xfer(xfer, mas, slv->mode, spi);
417 	return 1;
418 }
419 
420 static unsigned int geni_byte_per_fifo_word(struct spi_geni_master *mas)
421 {
422 	/*
423 	 * Calculate how many bytes we'll put in each FIFO word.  If the
424 	 * transfer words don't pack cleanly into a FIFO word we'll just put
425 	 * one transfer word in each FIFO word.  If they do pack we'll pack 'em.
426 	 */
427 	if (mas->fifo_width_bits % mas->cur_bits_per_word)
428 		return roundup_pow_of_two(DIV_ROUND_UP(mas->cur_bits_per_word,
429 						       BITS_PER_BYTE));
430 
431 	return mas->fifo_width_bits / BITS_PER_BYTE;
432 }
433 
434 static void geni_spi_handle_tx(struct spi_geni_master *mas)
435 {
436 	struct geni_se *se = &mas->se;
437 	unsigned int max_bytes;
438 	const u8 *tx_buf;
439 	unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
440 	unsigned int i = 0;
441 
442 	max_bytes = (mas->tx_fifo_depth - mas->tx_wm) * bytes_per_fifo_word;
443 	if (mas->tx_rem_bytes < max_bytes)
444 		max_bytes = mas->tx_rem_bytes;
445 
446 	tx_buf = mas->cur_xfer->tx_buf + mas->cur_xfer->len - mas->tx_rem_bytes;
447 	while (i < max_bytes) {
448 		unsigned int j;
449 		unsigned int bytes_to_write;
450 		u32 fifo_word = 0;
451 		u8 *fifo_byte = (u8 *)&fifo_word;
452 
453 		bytes_to_write = min(bytes_per_fifo_word, max_bytes - i);
454 		for (j = 0; j < bytes_to_write; j++)
455 			fifo_byte[j] = tx_buf[i++];
456 		iowrite32_rep(se->base + SE_GENI_TX_FIFOn, &fifo_word, 1);
457 	}
458 	mas->tx_rem_bytes -= max_bytes;
459 	if (!mas->tx_rem_bytes)
460 		writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
461 }
462 
463 static void geni_spi_handle_rx(struct spi_geni_master *mas)
464 {
465 	struct geni_se *se = &mas->se;
466 	u32 rx_fifo_status;
467 	unsigned int rx_bytes;
468 	unsigned int rx_last_byte_valid;
469 	u8 *rx_buf;
470 	unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
471 	unsigned int i = 0;
472 
473 	rx_fifo_status = readl(se->base + SE_GENI_RX_FIFO_STATUS);
474 	rx_bytes = (rx_fifo_status & RX_FIFO_WC_MSK) * bytes_per_fifo_word;
475 	if (rx_fifo_status & RX_LAST) {
476 		rx_last_byte_valid = rx_fifo_status & RX_LAST_BYTE_VALID_MSK;
477 		rx_last_byte_valid >>= RX_LAST_BYTE_VALID_SHFT;
478 		if (rx_last_byte_valid && rx_last_byte_valid < 4)
479 			rx_bytes -= bytes_per_fifo_word - rx_last_byte_valid;
480 	}
481 	if (mas->rx_rem_bytes < rx_bytes)
482 		rx_bytes = mas->rx_rem_bytes;
483 
484 	rx_buf = mas->cur_xfer->rx_buf + mas->cur_xfer->len - mas->rx_rem_bytes;
485 	while (i < rx_bytes) {
486 		u32 fifo_word = 0;
487 		u8 *fifo_byte = (u8 *)&fifo_word;
488 		unsigned int bytes_to_read;
489 		unsigned int j;
490 
491 		bytes_to_read = min(bytes_per_fifo_word, rx_bytes - i);
492 		ioread32_rep(se->base + SE_GENI_RX_FIFOn, &fifo_word, 1);
493 		for (j = 0; j < bytes_to_read; j++)
494 			rx_buf[i++] = fifo_byte[j];
495 	}
496 	mas->rx_rem_bytes -= rx_bytes;
497 }
498 
499 static irqreturn_t geni_spi_isr(int irq, void *data)
500 {
501 	struct spi_master *spi = data;
502 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
503 	struct geni_se *se = &mas->se;
504 	u32 m_irq;
505 
506 	m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
507 	if (!m_irq)
508 		return IRQ_NONE;
509 
510 	if (m_irq & (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN |
511 		     M_RX_FIFO_RD_ERR_EN | M_RX_FIFO_WR_ERR_EN |
512 		     M_TX_FIFO_RD_ERR_EN | M_TX_FIFO_WR_ERR_EN))
513 		dev_warn(mas->dev, "Unexpected IRQ err status %#010x\n", m_irq);
514 
515 	spin_lock(&mas->lock);
516 
517 	if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
518 		geni_spi_handle_rx(mas);
519 
520 	if (m_irq & M_TX_FIFO_WATERMARK_EN)
521 		geni_spi_handle_tx(mas);
522 
523 	if (m_irq & M_CMD_DONE_EN) {
524 		if (mas->cur_xfer) {
525 			spi_finalize_current_transfer(spi);
526 			mas->cur_xfer = NULL;
527 			/*
528 			 * If this happens, then a CMD_DONE came before all the
529 			 * Tx buffer bytes were sent out. This is unusual, log
530 			 * this condition and disable the WM interrupt to
531 			 * prevent the system from stalling due an interrupt
532 			 * storm.
533 			 *
534 			 * If this happens when all Rx bytes haven't been
535 			 * received, log the condition. The only known time
536 			 * this can happen is if bits_per_word != 8 and some
537 			 * registers that expect xfer lengths in num spi_words
538 			 * weren't written correctly.
539 			 */
540 			if (mas->tx_rem_bytes) {
541 				writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
542 				dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n",
543 					mas->tx_rem_bytes, mas->cur_bits_per_word);
544 			}
545 			if (mas->rx_rem_bytes)
546 				dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n",
547 					mas->rx_rem_bytes, mas->cur_bits_per_word);
548 		} else {
549 			complete(&mas->cs_done);
550 		}
551 	}
552 
553 	if (m_irq & M_CMD_CANCEL_EN)
554 		complete(&mas->cancel_done);
555 	if (m_irq & M_CMD_ABORT_EN)
556 		complete(&mas->abort_done);
557 
558 	/*
559 	 * It's safe or a good idea to Ack all of our our interrupts at the
560 	 * end of the function. Specifically:
561 	 * - M_CMD_DONE_EN / M_RX_FIFO_LAST_EN: Edge triggered interrupts and
562 	 *   clearing Acks. Clearing at the end relies on nobody else having
563 	 *   started a new transfer yet or else we could be clearing _their_
564 	 *   done bit, but everyone grabs the spinlock before starting a new
565 	 *   transfer.
566 	 * - M_RX_FIFO_WATERMARK_EN / M_TX_FIFO_WATERMARK_EN: These appear
567 	 *   to be "latched level" interrupts so it's important to clear them
568 	 *   _after_ you've handled the condition and always safe to do so
569 	 *   since they'll re-assert if they're still happening.
570 	 */
571 	writel(m_irq, se->base + SE_GENI_M_IRQ_CLEAR);
572 
573 	spin_unlock(&mas->lock);
574 
575 	return IRQ_HANDLED;
576 }
577 
578 static int spi_geni_probe(struct platform_device *pdev)
579 {
580 	int ret, irq;
581 	struct spi_master *spi;
582 	struct spi_geni_master *mas;
583 	void __iomem *base;
584 	struct clk *clk;
585 	struct device *dev = &pdev->dev;
586 
587 	irq = platform_get_irq(pdev, 0);
588 	if (irq < 0)
589 		return irq;
590 
591 	base = devm_platform_ioremap_resource(pdev, 0);
592 	if (IS_ERR(base))
593 		return PTR_ERR(base);
594 
595 	clk = devm_clk_get(dev, "se");
596 	if (IS_ERR(clk))
597 		return PTR_ERR(clk);
598 
599 	spi = spi_alloc_master(dev, sizeof(*mas));
600 	if (!spi)
601 		return -ENOMEM;
602 
603 	platform_set_drvdata(pdev, spi);
604 	mas = spi_master_get_devdata(spi);
605 	mas->irq = irq;
606 	mas->dev = dev;
607 	mas->se.dev = dev;
608 	mas->se.wrapper = dev_get_drvdata(dev->parent);
609 	mas->se.base = base;
610 	mas->se.clk = clk;
611 	mas->se.opp_table = dev_pm_opp_set_clkname(&pdev->dev, "se");
612 	if (IS_ERR(mas->se.opp_table))
613 		return PTR_ERR(mas->se.opp_table);
614 	/* OPP table is optional */
615 	ret = dev_pm_opp_of_add_table(&pdev->dev);
616 	if (!ret) {
617 		mas->se.has_opp_table = true;
618 	} else if (ret != -ENODEV) {
619 		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
620 		return ret;
621 	}
622 
623 	spi->bus_num = -1;
624 	spi->dev.of_node = dev->of_node;
625 	spi->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_CS_HIGH;
626 	spi->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
627 	spi->num_chipselect = 4;
628 	spi->max_speed_hz = 50000000;
629 	spi->prepare_message = spi_geni_prepare_message;
630 	spi->transfer_one = spi_geni_transfer_one;
631 	spi->auto_runtime_pm = true;
632 	spi->handle_err = handle_fifo_timeout;
633 	spi->set_cs = spi_geni_set_cs;
634 
635 	init_completion(&mas->cs_done);
636 	init_completion(&mas->cancel_done);
637 	init_completion(&mas->abort_done);
638 	spin_lock_init(&mas->lock);
639 	pm_runtime_use_autosuspend(&pdev->dev);
640 	pm_runtime_set_autosuspend_delay(&pdev->dev, 250);
641 	pm_runtime_enable(dev);
642 
643 	ret = geni_icc_get(&mas->se, NULL);
644 	if (ret)
645 		goto spi_geni_probe_runtime_disable;
646 	/* Set the bus quota to a reasonable value for register access */
647 	mas->se.icc_paths[GENI_TO_CORE].avg_bw = Bps_to_icc(CORE_2X_50_MHZ);
648 	mas->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
649 
650 	ret = geni_icc_set_bw(&mas->se);
651 	if (ret)
652 		goto spi_geni_probe_runtime_disable;
653 
654 	ret = spi_geni_init(mas);
655 	if (ret)
656 		goto spi_geni_probe_runtime_disable;
657 
658 	ret = request_irq(mas->irq, geni_spi_isr, 0, dev_name(dev), spi);
659 	if (ret)
660 		goto spi_geni_probe_runtime_disable;
661 
662 	ret = spi_register_master(spi);
663 	if (ret)
664 		goto spi_geni_probe_free_irq;
665 
666 	return 0;
667 spi_geni_probe_free_irq:
668 	free_irq(mas->irq, spi);
669 spi_geni_probe_runtime_disable:
670 	pm_runtime_disable(dev);
671 	spi_master_put(spi);
672 	if (mas->se.has_opp_table)
673 		dev_pm_opp_of_remove_table(&pdev->dev);
674 	dev_pm_opp_put_clkname(mas->se.opp_table);
675 	return ret;
676 }
677 
678 static int spi_geni_remove(struct platform_device *pdev)
679 {
680 	struct spi_master *spi = platform_get_drvdata(pdev);
681 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
682 
683 	/* Unregister _before_ disabling pm_runtime() so we stop transfers */
684 	spi_unregister_master(spi);
685 
686 	free_irq(mas->irq, spi);
687 	pm_runtime_disable(&pdev->dev);
688 	if (mas->se.has_opp_table)
689 		dev_pm_opp_of_remove_table(&pdev->dev);
690 	dev_pm_opp_put_clkname(mas->se.opp_table);
691 	return 0;
692 }
693 
694 static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
695 {
696 	struct spi_master *spi = dev_get_drvdata(dev);
697 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
698 	int ret;
699 
700 	/* Drop the performance state vote */
701 	dev_pm_opp_set_rate(dev, 0);
702 
703 	ret = geni_se_resources_off(&mas->se);
704 	if (ret)
705 		return ret;
706 
707 	return geni_icc_disable(&mas->se);
708 }
709 
710 static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
711 {
712 	struct spi_master *spi = dev_get_drvdata(dev);
713 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
714 	int ret;
715 
716 	ret = geni_icc_enable(&mas->se);
717 	if (ret)
718 		return ret;
719 
720 	ret = geni_se_resources_on(&mas->se);
721 	if (ret)
722 		return ret;
723 
724 	return dev_pm_opp_set_rate(mas->dev, mas->cur_sclk_hz);
725 }
726 
727 static int __maybe_unused spi_geni_suspend(struct device *dev)
728 {
729 	struct spi_master *spi = dev_get_drvdata(dev);
730 	int ret;
731 
732 	ret = spi_master_suspend(spi);
733 	if (ret)
734 		return ret;
735 
736 	ret = pm_runtime_force_suspend(dev);
737 	if (ret)
738 		spi_master_resume(spi);
739 
740 	return ret;
741 }
742 
743 static int __maybe_unused spi_geni_resume(struct device *dev)
744 {
745 	struct spi_master *spi = dev_get_drvdata(dev);
746 	int ret;
747 
748 	ret = pm_runtime_force_resume(dev);
749 	if (ret)
750 		return ret;
751 
752 	ret = spi_master_resume(spi);
753 	if (ret)
754 		pm_runtime_force_suspend(dev);
755 
756 	return ret;
757 }
758 
759 static const struct dev_pm_ops spi_geni_pm_ops = {
760 	SET_RUNTIME_PM_OPS(spi_geni_runtime_suspend,
761 					spi_geni_runtime_resume, NULL)
762 	SET_SYSTEM_SLEEP_PM_OPS(spi_geni_suspend, spi_geni_resume)
763 };
764 
765 static const struct of_device_id spi_geni_dt_match[] = {
766 	{ .compatible = "qcom,geni-spi" },
767 	{}
768 };
769 MODULE_DEVICE_TABLE(of, spi_geni_dt_match);
770 
771 static struct platform_driver spi_geni_driver = {
772 	.probe  = spi_geni_probe,
773 	.remove = spi_geni_remove,
774 	.driver = {
775 		.name = "geni_spi",
776 		.pm = &spi_geni_pm_ops,
777 		.of_match_table = spi_geni_dt_match,
778 	},
779 };
780 module_platform_driver(spi_geni_driver);
781 
782 MODULE_DESCRIPTION("SPI driver for GENI based QUP cores");
783 MODULE_LICENSE("GPL v2");
784