1 // SPDX-License-Identifier: (GPL-2.0)
2 /*
3  * Microchip CoreSPI SPI controller driver
4  *
5  * Copyright (c) 2018-2022 Microchip Technology Inc. and its subsidiaries
6  *
7  * Author: Daire McNamara <daire.mcnamara@microchip.com>
8  * Author: Conor Dooley <conor.dooley@microchip.com>
9  *
10  */
11 
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21 #include <linux/spi/spi.h>
22 
23 #define MAX_LEN				(0xffff)
24 #define MAX_CS				(1)
25 #define DEFAULT_FRAMESIZE		(8)
26 #define FIFO_DEPTH			(32)
27 #define CLK_GEN_MODE1_MAX		(255)
28 #define CLK_GEN_MODE0_MAX		(15)
29 #define CLK_GEN_MIN			(0)
30 #define MODE_X_MASK_SHIFT		(24)
31 
32 #define CONTROL_ENABLE			BIT(0)
33 #define CONTROL_MASTER			BIT(1)
34 #define CONTROL_RX_DATA_INT		BIT(4)
35 #define CONTROL_TX_DATA_INT		BIT(5)
36 #define CONTROL_RX_OVER_INT		BIT(6)
37 #define CONTROL_TX_UNDER_INT		BIT(7)
38 #define CONTROL_SPO			BIT(24)
39 #define CONTROL_SPH			BIT(25)
40 #define CONTROL_SPS			BIT(26)
41 #define CONTROL_FRAMEURUN		BIT(27)
42 #define CONTROL_CLKMODE			BIT(28)
43 #define CONTROL_BIGFIFO			BIT(29)
44 #define CONTROL_OENOFF			BIT(30)
45 #define CONTROL_RESET			BIT(31)
46 
47 #define CONTROL_MODE_MASK		GENMASK(3, 2)
48 #define  MOTOROLA_MODE			(0)
49 #define CONTROL_FRAMECNT_MASK		GENMASK(23, 8)
50 #define CONTROL_FRAMECNT_SHIFT		(8)
51 
52 #define STATUS_ACTIVE			BIT(14)
53 #define STATUS_SSEL			BIT(13)
54 #define STATUS_FRAMESTART		BIT(12)
55 #define STATUS_TXFIFO_EMPTY_NEXT_READ	BIT(11)
56 #define STATUS_TXFIFO_EMPTY		BIT(10)
57 #define STATUS_TXFIFO_FULL_NEXT_WRITE	BIT(9)
58 #define STATUS_TXFIFO_FULL		BIT(8)
59 #define STATUS_RXFIFO_EMPTY_NEXT_READ	BIT(7)
60 #define STATUS_RXFIFO_EMPTY		BIT(6)
61 #define STATUS_RXFIFO_FULL_NEXT_WRITE	BIT(5)
62 #define STATUS_RXFIFO_FULL		BIT(4)
63 #define STATUS_TX_UNDERRUN		BIT(3)
64 #define STATUS_RX_OVERFLOW		BIT(2)
65 #define STATUS_RXDAT_RXED		BIT(1)
66 #define STATUS_TXDAT_SENT		BIT(0)
67 
68 #define INT_TXDONE			BIT(0)
69 #define INT_RXRDY			BIT(1)
70 #define INT_RX_CHANNEL_OVERFLOW		BIT(2)
71 #define INT_TX_CHANNEL_UNDERRUN		BIT(3)
72 
73 #define INT_ENABLE_MASK (CONTROL_RX_DATA_INT | CONTROL_TX_DATA_INT | \
74 			 CONTROL_RX_OVER_INT | CONTROL_TX_UNDER_INT)
75 
76 #define REG_CONTROL		(0x00)
77 #define REG_FRAME_SIZE		(0x04)
78 #define  FRAME_SIZE_MASK	GENMASK(5, 0)
79 #define REG_STATUS		(0x08)
80 #define REG_INT_CLEAR		(0x0c)
81 #define REG_RX_DATA		(0x10)
82 #define REG_TX_DATA		(0x14)
83 #define REG_CLK_GEN		(0x18)
84 #define REG_SLAVE_SELECT	(0x1c)
85 #define  SSEL_MASK		GENMASK(7, 0)
86 #define  SSEL_DIRECT		BIT(8)
87 #define  SSELOUT_SHIFT		9
88 #define  SSELOUT		BIT(SSELOUT_SHIFT)
89 #define REG_MIS			(0x20)
90 #define REG_RIS			(0x24)
91 #define REG_CONTROL2		(0x28)
92 #define REG_COMMAND		(0x2c)
93 #define  COMMAND_CLRFRAMECNT	BIT(4)
94 #define  COMMAND_TXFIFORST		BIT(3)
95 #define  COMMAND_RXFIFORST		BIT(2)
96 #define REG_PKTSIZE		(0x30)
97 #define REG_CMD_SIZE		(0x34)
98 #define REG_HWSTATUS		(0x38)
99 #define REG_STAT8		(0x3c)
100 #define REG_CTRL2		(0x48)
101 #define REG_FRAMESUP		(0x50)
102 
103 struct mchp_corespi {
104 	void __iomem *regs;
105 	struct clk *clk;
106 	const u8 *tx_buf;
107 	u8 *rx_buf;
108 	u32 clk_gen; /* divider for spi output clock generated by the controller */
109 	u32 clk_mode;
110 	u32 pending_slave_select;
111 	int irq;
112 	int tx_len;
113 	int rx_len;
114 	int pending;
115 };
116 
117 static inline u32 mchp_corespi_read(struct mchp_corespi *spi, unsigned int reg)
118 {
119 	return readl(spi->regs + reg);
120 }
121 
122 static inline void mchp_corespi_write(struct mchp_corespi *spi, unsigned int reg, u32 val)
123 {
124 	writel(val, spi->regs + reg);
125 }
126 
127 static inline void mchp_corespi_disable(struct mchp_corespi *spi)
128 {
129 	u32 control = mchp_corespi_read(spi, REG_CONTROL);
130 
131 	control &= ~CONTROL_ENABLE;
132 
133 	mchp_corespi_write(spi, REG_CONTROL, control);
134 }
135 
136 static inline void mchp_corespi_read_fifo(struct mchp_corespi *spi)
137 {
138 	u8 data;
139 	int fifo_max, i = 0;
140 
141 	fifo_max = min(spi->rx_len, FIFO_DEPTH);
142 
143 	while ((i < fifo_max) && !(mchp_corespi_read(spi, REG_STATUS) & STATUS_RXFIFO_EMPTY)) {
144 		data = mchp_corespi_read(spi, REG_RX_DATA);
145 
146 		if (spi->rx_buf)
147 			*spi->rx_buf++ = data;
148 		i++;
149 	}
150 	spi->rx_len -= i;
151 	spi->pending -= i;
152 }
153 
154 static void mchp_corespi_enable_ints(struct mchp_corespi *spi)
155 {
156 	u32 control = mchp_corespi_read(spi, REG_CONTROL);
157 
158 	control |= INT_ENABLE_MASK;
159 	mchp_corespi_write(spi, REG_CONTROL, control);
160 }
161 
162 static void mchp_corespi_disable_ints(struct mchp_corespi *spi)
163 {
164 	u32 control = mchp_corespi_read(spi, REG_CONTROL);
165 
166 	control &= ~INT_ENABLE_MASK;
167 	mchp_corespi_write(spi, REG_CONTROL, control);
168 }
169 
170 static inline void mchp_corespi_set_xfer_size(struct mchp_corespi *spi, int len)
171 {
172 	u32 control;
173 	u32 lenpart;
174 	u32 frames = mchp_corespi_read(spi, REG_FRAMESUP);
175 
176 	/*
177 	 * Writing to FRAMECNT in REG_CONTROL will reset the frame count, taking
178 	 * a shortcut requires an explicit clear.
179 	 */
180 	if (frames == len) {
181 		mchp_corespi_write(spi, REG_COMMAND, COMMAND_CLRFRAMECNT);
182 		return;
183 	}
184 
185 	/*
186 	 * The lower 16 bits of the frame count are stored in the control reg
187 	 * for legacy reasons, but the upper 16 written to a different register:
188 	 * FRAMESUP. While both the upper and lower bits can be *READ* from the
189 	 * FRAMESUP register, writing to the lower 16 bits is (supposedly) a NOP.
190 	 *
191 	 * The driver used to disable the controller while modifying the frame
192 	 * count, and mask off the lower 16 bits of len while writing to
193 	 * FRAMES_UP. When the driver was changed to disable the controller as
194 	 * infrequently as possible, it was discovered that the logic of
195 	 * lenpart = len & 0xffff_0000
196 	 * write(REG_FRAMESUP, lenpart)
197 	 * would actually write zeros into the lower 16 bits on an mpfs250t-es,
198 	 * despite documentation stating these bits were read-only.
199 	 * Writing len unmasked into FRAMES_UP ensures those bits aren't zeroed
200 	 * on an mpfs250t-es and will be a NOP for the lower 16 bits on hardware
201 	 * that matches the documentation.
202 	 */
203 	lenpart = len & 0xffff;
204 	control = mchp_corespi_read(spi, REG_CONTROL);
205 	control &= ~CONTROL_FRAMECNT_MASK;
206 	control |= lenpart << CONTROL_FRAMECNT_SHIFT;
207 	mchp_corespi_write(spi, REG_CONTROL, control);
208 	mchp_corespi_write(spi, REG_FRAMESUP, len);
209 }
210 
211 static inline void mchp_corespi_write_fifo(struct mchp_corespi *spi)
212 {
213 	u8 byte;
214 	int fifo_max, i = 0;
215 
216 	fifo_max = min(spi->tx_len, FIFO_DEPTH);
217 	mchp_corespi_set_xfer_size(spi, fifo_max);
218 
219 	while ((i < fifo_max) && !(mchp_corespi_read(spi, REG_STATUS) & STATUS_TXFIFO_FULL)) {
220 		byte = spi->tx_buf ? *spi->tx_buf++ : 0xaa;
221 		mchp_corespi_write(spi, REG_TX_DATA, byte);
222 		i++;
223 	}
224 
225 	spi->tx_len -= i;
226 	spi->pending += i;
227 }
228 
229 static inline void mchp_corespi_set_framesize(struct mchp_corespi *spi, int bt)
230 {
231 	u32 frame_size = mchp_corespi_read(spi, REG_FRAME_SIZE);
232 	u32 control;
233 
234 	if ((frame_size & FRAME_SIZE_MASK) == bt)
235 		return;
236 
237 	/*
238 	 * Disable the SPI controller. Writes to the frame size have
239 	 * no effect when the controller is enabled.
240 	 */
241 	control = mchp_corespi_read(spi, REG_CONTROL);
242 	control &= ~CONTROL_ENABLE;
243 	mchp_corespi_write(spi, REG_CONTROL, control);
244 
245 	mchp_corespi_write(spi, REG_FRAME_SIZE, bt);
246 
247 	control |= CONTROL_ENABLE;
248 	mchp_corespi_write(spi, REG_CONTROL, control);
249 }
250 
251 static void mchp_corespi_set_cs(struct spi_device *spi, bool disable)
252 {
253 	u32 reg;
254 	struct mchp_corespi *corespi = spi_controller_get_devdata(spi->controller);
255 
256 	reg = mchp_corespi_read(corespi, REG_SLAVE_SELECT);
257 	reg &= ~BIT(spi_get_chipselect(spi, 0));
258 	reg |= !disable << spi_get_chipselect(spi, 0);
259 	corespi->pending_slave_select = reg;
260 
261 	/*
262 	 * Only deassert chip select immediately. Writing to some registers
263 	 * requires the controller to be disabled, which results in the
264 	 * output pins being tristated and can cause the SCLK and MOSI lines
265 	 * to transition. Therefore asserting the chip select is deferred
266 	 * until just before writing to the TX FIFO, to ensure the device
267 	 * doesn't see any spurious clock transitions whilst CS is enabled.
268 	 */
269 	if (((spi->mode & SPI_CS_HIGH) == 0) == disable)
270 		mchp_corespi_write(corespi, REG_SLAVE_SELECT, reg);
271 }
272 
273 static int mchp_corespi_setup(struct spi_device *spi)
274 {
275 	struct mchp_corespi *corespi = spi_controller_get_devdata(spi->controller);
276 	u32 reg;
277 
278 	/*
279 	 * Active high targets need to be specifically set to their inactive
280 	 * states during probe by adding them to the "control group" & thus
281 	 * driving their select line low.
282 	 */
283 	if (spi->mode & SPI_CS_HIGH) {
284 		reg = mchp_corespi_read(corespi, REG_SLAVE_SELECT);
285 		reg |= BIT(spi_get_chipselect(spi, 0));
286 		corespi->pending_slave_select = reg;
287 		mchp_corespi_write(corespi, REG_SLAVE_SELECT, reg);
288 	}
289 	return 0;
290 }
291 
292 static void mchp_corespi_init(struct spi_controller *host, struct mchp_corespi *spi)
293 {
294 	unsigned long clk_hz;
295 	u32 control = mchp_corespi_read(spi, REG_CONTROL);
296 
297 	control &= ~CONTROL_ENABLE;
298 	mchp_corespi_write(spi, REG_CONTROL, control);
299 
300 	control |= CONTROL_MASTER;
301 	control &= ~CONTROL_MODE_MASK;
302 	control |= MOTOROLA_MODE;
303 
304 	/*
305 	 * The controller must be configured so that it doesn't remove Chip
306 	 * Select until the entire message has been transferred, even if at
307 	 * some points TX FIFO becomes empty.
308 	 *
309 	 * BIGFIFO mode is also enabled, which sets the fifo depth to 32 frames
310 	 * for the 8 bit transfers that this driver uses.
311 	 */
312 	control |= CONTROL_SPS | CONTROL_BIGFIFO;
313 
314 	mchp_corespi_write(spi, REG_CONTROL, control);
315 
316 	mchp_corespi_set_framesize(spi, DEFAULT_FRAMESIZE);
317 
318 	/* max. possible spi clock rate is the apb clock rate */
319 	clk_hz = clk_get_rate(spi->clk);
320 	host->max_speed_hz = clk_hz;
321 
322 	mchp_corespi_enable_ints(spi);
323 
324 	/*
325 	 * It is required to enable direct mode, otherwise control over the chip
326 	 * select is relinquished to the hardware. SSELOUT is enabled too so we
327 	 * can deal with active high targets.
328 	 */
329 	spi->pending_slave_select = SSELOUT | SSEL_DIRECT;
330 	mchp_corespi_write(spi, REG_SLAVE_SELECT, spi->pending_slave_select);
331 
332 	control = mchp_corespi_read(spi, REG_CONTROL);
333 
334 	control &= ~CONTROL_RESET;
335 	control |= CONTROL_ENABLE;
336 
337 	mchp_corespi_write(spi, REG_CONTROL, control);
338 }
339 
340 static inline void mchp_corespi_set_clk_gen(struct mchp_corespi *spi)
341 {
342 	u32 control;
343 
344 	control = mchp_corespi_read(spi, REG_CONTROL);
345 	if (spi->clk_mode)
346 		control |= CONTROL_CLKMODE;
347 	else
348 		control &= ~CONTROL_CLKMODE;
349 
350 	mchp_corespi_write(spi, REG_CLK_GEN, spi->clk_gen);
351 	mchp_corespi_write(spi, REG_CONTROL, control);
352 }
353 
354 static inline void mchp_corespi_set_mode(struct mchp_corespi *spi, unsigned int mode)
355 {
356 	u32 mode_val;
357 	u32 control = mchp_corespi_read(spi, REG_CONTROL);
358 
359 	switch (mode & SPI_MODE_X_MASK) {
360 	case SPI_MODE_0:
361 		mode_val = 0;
362 		break;
363 	case SPI_MODE_1:
364 		mode_val = CONTROL_SPH;
365 		break;
366 	case SPI_MODE_2:
367 		mode_val = CONTROL_SPO;
368 		break;
369 	case SPI_MODE_3:
370 		mode_val = CONTROL_SPH | CONTROL_SPO;
371 		break;
372 	}
373 
374 	/*
375 	 * Disable the SPI controller. Writes to the frame protocol have
376 	 * no effect when the controller is enabled.
377 	 */
378 
379 	control &= ~CONTROL_ENABLE;
380 	mchp_corespi_write(spi, REG_CONTROL, control);
381 
382 	control &= ~(SPI_MODE_X_MASK << MODE_X_MASK_SHIFT);
383 	control |= mode_val;
384 
385 	mchp_corespi_write(spi, REG_CONTROL, control);
386 
387 	control |= CONTROL_ENABLE;
388 	mchp_corespi_write(spi, REG_CONTROL, control);
389 }
390 
391 static irqreturn_t mchp_corespi_interrupt(int irq, void *dev_id)
392 {
393 	struct spi_controller *host = dev_id;
394 	struct mchp_corespi *spi = spi_controller_get_devdata(host);
395 	u32 intfield = mchp_corespi_read(spi, REG_MIS) & 0xf;
396 	bool finalise = false;
397 
398 	/* Interrupt line may be shared and not for us at all */
399 	if (intfield == 0)
400 		return IRQ_NONE;
401 
402 	if (intfield & INT_TXDONE)
403 		mchp_corespi_write(spi, REG_INT_CLEAR, INT_TXDONE);
404 
405 	if (intfield & INT_RXRDY) {
406 		mchp_corespi_write(spi, REG_INT_CLEAR, INT_RXRDY);
407 
408 		if (spi->rx_len)
409 			mchp_corespi_read_fifo(spi);
410 	}
411 
412 	if (!spi->rx_len && !spi->tx_len)
413 		finalise = true;
414 
415 	if (intfield & INT_RX_CHANNEL_OVERFLOW) {
416 		mchp_corespi_write(spi, REG_INT_CLEAR, INT_RX_CHANNEL_OVERFLOW);
417 		finalise = true;
418 		dev_err(&host->dev,
419 			"%s: RX OVERFLOW: rxlen: %d, txlen: %d\n", __func__,
420 			spi->rx_len, spi->tx_len);
421 	}
422 
423 	if (intfield & INT_TX_CHANNEL_UNDERRUN) {
424 		mchp_corespi_write(spi, REG_INT_CLEAR, INT_TX_CHANNEL_UNDERRUN);
425 		finalise = true;
426 		dev_err(&host->dev,
427 			"%s: TX UNDERFLOW: rxlen: %d, txlen: %d\n", __func__,
428 			spi->rx_len, spi->tx_len);
429 	}
430 
431 	if (finalise)
432 		spi_finalize_current_transfer(host);
433 
434 	return IRQ_HANDLED;
435 }
436 
437 static int mchp_corespi_calculate_clkgen(struct mchp_corespi *spi,
438 					 unsigned long target_hz)
439 {
440 	unsigned long clk_hz, spi_hz, clk_gen;
441 
442 	clk_hz = clk_get_rate(spi->clk);
443 	if (!clk_hz)
444 		return -EINVAL;
445 	spi_hz = min(target_hz, clk_hz);
446 
447 	/*
448 	 * There are two possible clock modes for the controller generated
449 	 * clock's division ratio:
450 	 * CLK_MODE = 0: 1 / (2^(CLK_GEN + 1)) where CLK_GEN = 0 to 15.
451 	 * CLK_MODE = 1: 1 / (2 * CLK_GEN + 1) where CLK_GEN = 0 to 255.
452 	 * First try mode 1, fall back to 0 and if we have tried both modes and
453 	 * we /still/ can't get a good setting, we then throw the toys out of
454 	 * the pram and give up
455 	 * clk_gen is the register name for the clock divider on MPFS.
456 	 */
457 	clk_gen = DIV_ROUND_UP(clk_hz, 2 * spi_hz) - 1;
458 	if (clk_gen > CLK_GEN_MODE1_MAX || clk_gen <= CLK_GEN_MIN) {
459 		clk_gen = DIV_ROUND_UP(clk_hz, spi_hz);
460 		clk_gen = fls(clk_gen) - 1;
461 
462 		if (clk_gen > CLK_GEN_MODE0_MAX)
463 			return -EINVAL;
464 
465 		spi->clk_mode = 0;
466 	} else {
467 		spi->clk_mode = 1;
468 	}
469 
470 	spi->clk_gen = clk_gen;
471 	return 0;
472 }
473 
474 static int mchp_corespi_transfer_one(struct spi_controller *host,
475 				     struct spi_device *spi_dev,
476 				     struct spi_transfer *xfer)
477 {
478 	struct mchp_corespi *spi = spi_controller_get_devdata(host);
479 	int ret;
480 
481 	ret = mchp_corespi_calculate_clkgen(spi, (unsigned long)xfer->speed_hz);
482 	if (ret) {
483 		dev_err(&host->dev, "failed to set clk_gen for target %u Hz\n", xfer->speed_hz);
484 		return ret;
485 	}
486 
487 	mchp_corespi_set_clk_gen(spi);
488 
489 	spi->tx_buf = xfer->tx_buf;
490 	spi->rx_buf = xfer->rx_buf;
491 	spi->tx_len = xfer->len;
492 	spi->rx_len = xfer->len;
493 	spi->pending = 0;
494 
495 	mchp_corespi_set_xfer_size(spi, (spi->tx_len > FIFO_DEPTH)
496 				   ? FIFO_DEPTH : spi->tx_len);
497 
498 	mchp_corespi_write(spi, REG_COMMAND, COMMAND_RXFIFORST | COMMAND_TXFIFORST);
499 
500 	mchp_corespi_write(spi, REG_SLAVE_SELECT, spi->pending_slave_select);
501 
502 	while (spi->tx_len)
503 		mchp_corespi_write_fifo(spi);
504 
505 	return 1;
506 }
507 
508 static int mchp_corespi_prepare_message(struct spi_controller *host,
509 					struct spi_message *msg)
510 {
511 	struct spi_device *spi_dev = msg->spi;
512 	struct mchp_corespi *spi = spi_controller_get_devdata(host);
513 
514 	mchp_corespi_set_framesize(spi, DEFAULT_FRAMESIZE);
515 	mchp_corespi_set_mode(spi, spi_dev->mode);
516 
517 	return 0;
518 }
519 
520 static int mchp_corespi_probe(struct platform_device *pdev)
521 {
522 	struct spi_controller *host;
523 	struct mchp_corespi *spi;
524 	struct resource *res;
525 	u32 num_cs;
526 	int ret = 0;
527 
528 	host = devm_spi_alloc_host(&pdev->dev, sizeof(*spi));
529 	if (!host)
530 		return dev_err_probe(&pdev->dev, -ENOMEM,
531 				     "unable to allocate host for SPI controller\n");
532 
533 	platform_set_drvdata(pdev, host);
534 
535 	if (of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs))
536 		num_cs = MAX_CS;
537 
538 	host->num_chipselect = num_cs;
539 	host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
540 	host->setup = mchp_corespi_setup;
541 	host->bits_per_word_mask = SPI_BPW_MASK(8);
542 	host->transfer_one = mchp_corespi_transfer_one;
543 	host->prepare_message = mchp_corespi_prepare_message;
544 	host->set_cs = mchp_corespi_set_cs;
545 	host->dev.of_node = pdev->dev.of_node;
546 
547 	spi = spi_controller_get_devdata(host);
548 
549 	spi->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
550 	if (IS_ERR(spi->regs))
551 		return PTR_ERR(spi->regs);
552 
553 	spi->irq = platform_get_irq(pdev, 0);
554 	if (spi->irq < 0)
555 		return spi->irq;
556 
557 	ret = devm_request_irq(&pdev->dev, spi->irq, mchp_corespi_interrupt,
558 			       IRQF_SHARED, dev_name(&pdev->dev), host);
559 	if (ret)
560 		return dev_err_probe(&pdev->dev, ret,
561 				     "could not request irq\n");
562 
563 	spi->clk = devm_clk_get(&pdev->dev, NULL);
564 	if (IS_ERR(spi->clk))
565 		return dev_err_probe(&pdev->dev, PTR_ERR(spi->clk),
566 				     "could not get clk\n");
567 
568 	ret = clk_prepare_enable(spi->clk);
569 	if (ret)
570 		return dev_err_probe(&pdev->dev, ret,
571 				     "failed to enable clock\n");
572 
573 	mchp_corespi_init(host, spi);
574 
575 	ret = devm_spi_register_controller(&pdev->dev, host);
576 	if (ret) {
577 		mchp_corespi_disable(spi);
578 		clk_disable_unprepare(spi->clk);
579 		return dev_err_probe(&pdev->dev, ret,
580 				     "unable to register host for SPI controller\n");
581 	}
582 
583 	dev_info(&pdev->dev, "Registered SPI controller %d\n", host->bus_num);
584 
585 	return 0;
586 }
587 
588 static void mchp_corespi_remove(struct platform_device *pdev)
589 {
590 	struct spi_controller *host  = platform_get_drvdata(pdev);
591 	struct mchp_corespi *spi = spi_controller_get_devdata(host);
592 
593 	mchp_corespi_disable_ints(spi);
594 	clk_disable_unprepare(spi->clk);
595 	mchp_corespi_disable(spi);
596 }
597 
598 #define MICROCHIP_SPI_PM_OPS (NULL)
599 
600 /*
601  * Platform driver data structure
602  */
603 
604 #if defined(CONFIG_OF)
605 static const struct of_device_id mchp_corespi_dt_ids[] = {
606 	{ .compatible = "microchip,mpfs-spi" },
607 	{ /* sentinel */ }
608 };
609 MODULE_DEVICE_TABLE(of, mchp_corespi_dt_ids);
610 #endif
611 
612 static struct platform_driver mchp_corespi_driver = {
613 	.probe = mchp_corespi_probe,
614 	.driver = {
615 		.name = "microchip-corespi",
616 		.pm = MICROCHIP_SPI_PM_OPS,
617 		.of_match_table = of_match_ptr(mchp_corespi_dt_ids),
618 	},
619 	.remove_new = mchp_corespi_remove,
620 };
621 module_platform_driver(mchp_corespi_driver);
622 MODULE_DESCRIPTION("Microchip coreSPI SPI controller driver");
623 MODULE_AUTHOR("Daire McNamara <daire.mcnamara@microchip.com>");
624 MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
625 MODULE_LICENSE("GPL");
626