xref: /openbmc/linux/drivers/spi/spi-geni-qcom.c (revision dfe94d40)
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 	u32 spi_tx_cfg;
294 
295 	pm_runtime_get_sync(mas->dev);
296 
297 	proto = geni_se_read_proto(se);
298 	if (proto != GENI_SE_SPI) {
299 		dev_err(mas->dev, "Invalid proto %d\n", proto);
300 		pm_runtime_put(mas->dev);
301 		return -ENXIO;
302 	}
303 	mas->tx_fifo_depth = geni_se_get_tx_fifo_depth(se);
304 
305 	/* Width of Tx and Rx FIFO is same */
306 	mas->fifo_width_bits = geni_se_get_tx_fifo_width(se);
307 
308 	/*
309 	 * Hardware programming guide suggests to configure
310 	 * RX FIFO RFR level to fifo_depth-2.
311 	 */
312 	geni_se_init(se, mas->tx_fifo_depth - 3, mas->tx_fifo_depth - 2);
313 	/* Transmit an entire FIFO worth of data per IRQ */
314 	mas->tx_wm = 1;
315 	ver = geni_se_get_qup_hw_version(se);
316 	major = GENI_SE_VERSION_MAJOR(ver);
317 	minor = GENI_SE_VERSION_MINOR(ver);
318 
319 	if (major == 1 && minor == 0)
320 		mas->oversampling = 2;
321 	else
322 		mas->oversampling = 1;
323 
324 	geni_se_select_mode(se, GENI_SE_FIFO);
325 
326 	/* We always control CS manually */
327 	spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
328 	spi_tx_cfg &= ~CS_TOGGLE;
329 	writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
330 
331 	pm_runtime_put(mas->dev);
332 	return 0;
333 }
334 
335 static unsigned int geni_byte_per_fifo_word(struct spi_geni_master *mas)
336 {
337 	/*
338 	 * Calculate how many bytes we'll put in each FIFO word.  If the
339 	 * transfer words don't pack cleanly into a FIFO word we'll just put
340 	 * one transfer word in each FIFO word.  If they do pack we'll pack 'em.
341 	 */
342 	if (mas->fifo_width_bits % mas->cur_bits_per_word)
343 		return roundup_pow_of_two(DIV_ROUND_UP(mas->cur_bits_per_word,
344 						       BITS_PER_BYTE));
345 
346 	return mas->fifo_width_bits / BITS_PER_BYTE;
347 }
348 
349 static bool geni_spi_handle_tx(struct spi_geni_master *mas)
350 {
351 	struct geni_se *se = &mas->se;
352 	unsigned int max_bytes;
353 	const u8 *tx_buf;
354 	unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
355 	unsigned int i = 0;
356 
357 	max_bytes = (mas->tx_fifo_depth - mas->tx_wm) * bytes_per_fifo_word;
358 	if (mas->tx_rem_bytes < max_bytes)
359 		max_bytes = mas->tx_rem_bytes;
360 
361 	tx_buf = mas->cur_xfer->tx_buf + mas->cur_xfer->len - mas->tx_rem_bytes;
362 	while (i < max_bytes) {
363 		unsigned int j;
364 		unsigned int bytes_to_write;
365 		u32 fifo_word = 0;
366 		u8 *fifo_byte = (u8 *)&fifo_word;
367 
368 		bytes_to_write = min(bytes_per_fifo_word, max_bytes - i);
369 		for (j = 0; j < bytes_to_write; j++)
370 			fifo_byte[j] = tx_buf[i++];
371 		iowrite32_rep(se->base + SE_GENI_TX_FIFOn, &fifo_word, 1);
372 	}
373 	mas->tx_rem_bytes -= max_bytes;
374 	if (!mas->tx_rem_bytes) {
375 		writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
376 		return false;
377 	}
378 	return true;
379 }
380 
381 static void geni_spi_handle_rx(struct spi_geni_master *mas)
382 {
383 	struct geni_se *se = &mas->se;
384 	u32 rx_fifo_status;
385 	unsigned int rx_bytes;
386 	unsigned int rx_last_byte_valid;
387 	u8 *rx_buf;
388 	unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
389 	unsigned int i = 0;
390 
391 	rx_fifo_status = readl(se->base + SE_GENI_RX_FIFO_STATUS);
392 	rx_bytes = (rx_fifo_status & RX_FIFO_WC_MSK) * bytes_per_fifo_word;
393 	if (rx_fifo_status & RX_LAST) {
394 		rx_last_byte_valid = rx_fifo_status & RX_LAST_BYTE_VALID_MSK;
395 		rx_last_byte_valid >>= RX_LAST_BYTE_VALID_SHFT;
396 		if (rx_last_byte_valid && rx_last_byte_valid < 4)
397 			rx_bytes -= bytes_per_fifo_word - rx_last_byte_valid;
398 	}
399 	if (mas->rx_rem_bytes < rx_bytes)
400 		rx_bytes = mas->rx_rem_bytes;
401 
402 	rx_buf = mas->cur_xfer->rx_buf + mas->cur_xfer->len - mas->rx_rem_bytes;
403 	while (i < rx_bytes) {
404 		u32 fifo_word = 0;
405 		u8 *fifo_byte = (u8 *)&fifo_word;
406 		unsigned int bytes_to_read;
407 		unsigned int j;
408 
409 		bytes_to_read = min(bytes_per_fifo_word, rx_bytes - i);
410 		ioread32_rep(se->base + SE_GENI_RX_FIFOn, &fifo_word, 1);
411 		for (j = 0; j < bytes_to_read; j++)
412 			rx_buf[i++] = fifo_byte[j];
413 	}
414 	mas->rx_rem_bytes -= rx_bytes;
415 }
416 
417 static void setup_fifo_xfer(struct spi_transfer *xfer,
418 				struct spi_geni_master *mas,
419 				u16 mode, struct spi_master *spi)
420 {
421 	u32 m_cmd = 0;
422 	u32 len;
423 	struct geni_se *se = &mas->se;
424 	int ret;
425 
426 	/*
427 	 * Ensure that our interrupt handler isn't still running from some
428 	 * prior command before we start messing with the hardware behind
429 	 * its back.  We don't need to _keep_ the lock here since we're only
430 	 * worried about racing with out interrupt handler.  The SPI core
431 	 * already handles making sure that we're not trying to do two
432 	 * transfers at once or setting a chip select and doing a transfer
433 	 * concurrently.
434 	 *
435 	 * NOTE: we actually _can't_ hold the lock here because possibly we
436 	 * might call clk_set_rate() which needs to be able to sleep.
437 	 */
438 	spin_lock_irq(&mas->lock);
439 	spin_unlock_irq(&mas->lock);
440 
441 	if (xfer->bits_per_word != mas->cur_bits_per_word) {
442 		spi_setup_word_len(mas, mode, xfer->bits_per_word);
443 		mas->cur_bits_per_word = xfer->bits_per_word;
444 	}
445 
446 	/* Speed and bits per word can be overridden per transfer */
447 	ret = geni_spi_set_clock_and_bw(mas, xfer->speed_hz);
448 	if (ret)
449 		return;
450 
451 	mas->tx_rem_bytes = 0;
452 	mas->rx_rem_bytes = 0;
453 
454 	if (!(mas->cur_bits_per_word % MIN_WORD_LEN))
455 		len = xfer->len * BITS_PER_BYTE / mas->cur_bits_per_word;
456 	else
457 		len = xfer->len / (mas->cur_bits_per_word / BITS_PER_BYTE + 1);
458 	len &= TRANS_LEN_MSK;
459 
460 	mas->cur_xfer = xfer;
461 	if (xfer->tx_buf) {
462 		m_cmd |= SPI_TX_ONLY;
463 		mas->tx_rem_bytes = xfer->len;
464 		writel(len, se->base + SE_SPI_TX_TRANS_LEN);
465 	}
466 
467 	if (xfer->rx_buf) {
468 		m_cmd |= SPI_RX_ONLY;
469 		writel(len, se->base + SE_SPI_RX_TRANS_LEN);
470 		mas->rx_rem_bytes = xfer->len;
471 	}
472 
473 	/*
474 	 * Lock around right before we start the transfer since our
475 	 * interrupt could come in at any time now.
476 	 */
477 	spin_lock_irq(&mas->lock);
478 	geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
479 
480 	/*
481 	 * TX_WATERMARK_REG should be set after SPI configuration and
482 	 * setting up GENI SE engine, as driver starts data transfer
483 	 * for the watermark interrupt.
484 	 */
485 	if (m_cmd & SPI_TX_ONLY) {
486 		if (geni_spi_handle_tx(mas))
487 			writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
488 	}
489 	spin_unlock_irq(&mas->lock);
490 }
491 
492 static int spi_geni_transfer_one(struct spi_master *spi,
493 				struct spi_device *slv,
494 				struct spi_transfer *xfer)
495 {
496 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
497 
498 	/* Terminate and return success for 0 byte length transfer */
499 	if (!xfer->len)
500 		return 0;
501 
502 	setup_fifo_xfer(xfer, mas, slv->mode, spi);
503 	return 1;
504 }
505 
506 static irqreturn_t geni_spi_isr(int irq, void *data)
507 {
508 	struct spi_master *spi = data;
509 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
510 	struct geni_se *se = &mas->se;
511 	u32 m_irq;
512 
513 	m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
514 	if (!m_irq)
515 		return IRQ_NONE;
516 
517 	if (m_irq & (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN |
518 		     M_RX_FIFO_RD_ERR_EN | M_RX_FIFO_WR_ERR_EN |
519 		     M_TX_FIFO_RD_ERR_EN | M_TX_FIFO_WR_ERR_EN))
520 		dev_warn(mas->dev, "Unexpected IRQ err status %#010x\n", m_irq);
521 
522 	spin_lock(&mas->lock);
523 
524 	if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
525 		geni_spi_handle_rx(mas);
526 
527 	if (m_irq & M_TX_FIFO_WATERMARK_EN)
528 		geni_spi_handle_tx(mas);
529 
530 	if (m_irq & M_CMD_DONE_EN) {
531 		if (mas->cur_xfer) {
532 			spi_finalize_current_transfer(spi);
533 			mas->cur_xfer = NULL;
534 			/*
535 			 * If this happens, then a CMD_DONE came before all the
536 			 * Tx buffer bytes were sent out. This is unusual, log
537 			 * this condition and disable the WM interrupt to
538 			 * prevent the system from stalling due an interrupt
539 			 * storm.
540 			 *
541 			 * If this happens when all Rx bytes haven't been
542 			 * received, log the condition. The only known time
543 			 * this can happen is if bits_per_word != 8 and some
544 			 * registers that expect xfer lengths in num spi_words
545 			 * weren't written correctly.
546 			 */
547 			if (mas->tx_rem_bytes) {
548 				writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
549 				dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n",
550 					mas->tx_rem_bytes, mas->cur_bits_per_word);
551 			}
552 			if (mas->rx_rem_bytes)
553 				dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n",
554 					mas->rx_rem_bytes, mas->cur_bits_per_word);
555 		} else {
556 			complete(&mas->cs_done);
557 		}
558 	}
559 
560 	if (m_irq & M_CMD_CANCEL_EN)
561 		complete(&mas->cancel_done);
562 	if (m_irq & M_CMD_ABORT_EN)
563 		complete(&mas->abort_done);
564 
565 	/*
566 	 * It's safe or a good idea to Ack all of our our interrupts at the
567 	 * end of the function. Specifically:
568 	 * - M_CMD_DONE_EN / M_RX_FIFO_LAST_EN: Edge triggered interrupts and
569 	 *   clearing Acks. Clearing at the end relies on nobody else having
570 	 *   started a new transfer yet or else we could be clearing _their_
571 	 *   done bit, but everyone grabs the spinlock before starting a new
572 	 *   transfer.
573 	 * - M_RX_FIFO_WATERMARK_EN / M_TX_FIFO_WATERMARK_EN: These appear
574 	 *   to be "latched level" interrupts so it's important to clear them
575 	 *   _after_ you've handled the condition and always safe to do so
576 	 *   since they'll re-assert if they're still happening.
577 	 */
578 	writel(m_irq, se->base + SE_GENI_M_IRQ_CLEAR);
579 
580 	spin_unlock(&mas->lock);
581 
582 	return IRQ_HANDLED;
583 }
584 
585 static int spi_geni_probe(struct platform_device *pdev)
586 {
587 	int ret, irq;
588 	struct spi_master *spi;
589 	struct spi_geni_master *mas;
590 	void __iomem *base;
591 	struct clk *clk;
592 	struct device *dev = &pdev->dev;
593 
594 	irq = platform_get_irq(pdev, 0);
595 	if (irq < 0)
596 		return irq;
597 
598 	base = devm_platform_ioremap_resource(pdev, 0);
599 	if (IS_ERR(base))
600 		return PTR_ERR(base);
601 
602 	clk = devm_clk_get(dev, "se");
603 	if (IS_ERR(clk))
604 		return PTR_ERR(clk);
605 
606 	spi = devm_spi_alloc_master(dev, sizeof(*mas));
607 	if (!spi)
608 		return -ENOMEM;
609 
610 	platform_set_drvdata(pdev, spi);
611 	mas = spi_master_get_devdata(spi);
612 	mas->irq = irq;
613 	mas->dev = dev;
614 	mas->se.dev = dev;
615 	mas->se.wrapper = dev_get_drvdata(dev->parent);
616 	mas->se.base = base;
617 	mas->se.clk = clk;
618 	mas->se.opp_table = dev_pm_opp_set_clkname(&pdev->dev, "se");
619 	if (IS_ERR(mas->se.opp_table))
620 		return PTR_ERR(mas->se.opp_table);
621 	/* OPP table is optional */
622 	ret = dev_pm_opp_of_add_table(&pdev->dev);
623 	if (ret && ret != -ENODEV) {
624 		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
625 		goto put_clkname;
626 	}
627 
628 	spi->bus_num = -1;
629 	spi->dev.of_node = dev->of_node;
630 	spi->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_CS_HIGH;
631 	spi->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
632 	spi->num_chipselect = 4;
633 	spi->max_speed_hz = 50000000;
634 	spi->prepare_message = spi_geni_prepare_message;
635 	spi->transfer_one = spi_geni_transfer_one;
636 	spi->auto_runtime_pm = true;
637 	spi->handle_err = handle_fifo_timeout;
638 	spi->set_cs = spi_geni_set_cs;
639 	spi->use_gpio_descriptors = true;
640 
641 	init_completion(&mas->cs_done);
642 	init_completion(&mas->cancel_done);
643 	init_completion(&mas->abort_done);
644 	spin_lock_init(&mas->lock);
645 	pm_runtime_use_autosuspend(&pdev->dev);
646 	pm_runtime_set_autosuspend_delay(&pdev->dev, 250);
647 	pm_runtime_enable(dev);
648 
649 	ret = geni_icc_get(&mas->se, NULL);
650 	if (ret)
651 		goto spi_geni_probe_runtime_disable;
652 	/* Set the bus quota to a reasonable value for register access */
653 	mas->se.icc_paths[GENI_TO_CORE].avg_bw = Bps_to_icc(CORE_2X_50_MHZ);
654 	mas->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
655 
656 	ret = geni_icc_set_bw(&mas->se);
657 	if (ret)
658 		goto spi_geni_probe_runtime_disable;
659 
660 	ret = spi_geni_init(mas);
661 	if (ret)
662 		goto spi_geni_probe_runtime_disable;
663 
664 	ret = request_irq(mas->irq, geni_spi_isr, 0, dev_name(dev), spi);
665 	if (ret)
666 		goto spi_geni_probe_runtime_disable;
667 
668 	ret = spi_register_master(spi);
669 	if (ret)
670 		goto spi_geni_probe_free_irq;
671 
672 	return 0;
673 spi_geni_probe_free_irq:
674 	free_irq(mas->irq, spi);
675 spi_geni_probe_runtime_disable:
676 	pm_runtime_disable(dev);
677 	dev_pm_opp_of_remove_table(&pdev->dev);
678 put_clkname:
679 	dev_pm_opp_put_clkname(mas->se.opp_table);
680 	return ret;
681 }
682 
683 static int spi_geni_remove(struct platform_device *pdev)
684 {
685 	struct spi_master *spi = platform_get_drvdata(pdev);
686 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
687 
688 	/* Unregister _before_ disabling pm_runtime() so we stop transfers */
689 	spi_unregister_master(spi);
690 
691 	free_irq(mas->irq, spi);
692 	pm_runtime_disable(&pdev->dev);
693 	dev_pm_opp_of_remove_table(&pdev->dev);
694 	dev_pm_opp_put_clkname(mas->se.opp_table);
695 	return 0;
696 }
697 
698 static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
699 {
700 	struct spi_master *spi = dev_get_drvdata(dev);
701 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
702 	int ret;
703 
704 	/* Drop the performance state vote */
705 	dev_pm_opp_set_rate(dev, 0);
706 
707 	ret = geni_se_resources_off(&mas->se);
708 	if (ret)
709 		return ret;
710 
711 	return geni_icc_disable(&mas->se);
712 }
713 
714 static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
715 {
716 	struct spi_master *spi = dev_get_drvdata(dev);
717 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
718 	int ret;
719 
720 	ret = geni_icc_enable(&mas->se);
721 	if (ret)
722 		return ret;
723 
724 	ret = geni_se_resources_on(&mas->se);
725 	if (ret)
726 		return ret;
727 
728 	return dev_pm_opp_set_rate(mas->dev, mas->cur_sclk_hz);
729 }
730 
731 static int __maybe_unused spi_geni_suspend(struct device *dev)
732 {
733 	struct spi_master *spi = dev_get_drvdata(dev);
734 	int ret;
735 
736 	ret = spi_master_suspend(spi);
737 	if (ret)
738 		return ret;
739 
740 	ret = pm_runtime_force_suspend(dev);
741 	if (ret)
742 		spi_master_resume(spi);
743 
744 	return ret;
745 }
746 
747 static int __maybe_unused spi_geni_resume(struct device *dev)
748 {
749 	struct spi_master *spi = dev_get_drvdata(dev);
750 	int ret;
751 
752 	ret = pm_runtime_force_resume(dev);
753 	if (ret)
754 		return ret;
755 
756 	ret = spi_master_resume(spi);
757 	if (ret)
758 		pm_runtime_force_suspend(dev);
759 
760 	return ret;
761 }
762 
763 static const struct dev_pm_ops spi_geni_pm_ops = {
764 	SET_RUNTIME_PM_OPS(spi_geni_runtime_suspend,
765 					spi_geni_runtime_resume, NULL)
766 	SET_SYSTEM_SLEEP_PM_OPS(spi_geni_suspend, spi_geni_resume)
767 };
768 
769 static const struct of_device_id spi_geni_dt_match[] = {
770 	{ .compatible = "qcom,geni-spi" },
771 	{}
772 };
773 MODULE_DEVICE_TABLE(of, spi_geni_dt_match);
774 
775 static struct platform_driver spi_geni_driver = {
776 	.probe  = spi_geni_probe,
777 	.remove = spi_geni_remove,
778 	.driver = {
779 		.name = "geni_spi",
780 		.pm = &spi_geni_pm_ops,
781 		.of_match_table = spi_geni_dt_match,
782 	},
783 };
784 module_platform_driver(spi_geni_driver);
785 
786 MODULE_DESCRIPTION("SPI driver for GENI based QUP cores");
787 MODULE_LICENSE("GPL v2");
788