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  1/*
  2 * Driver for Amlogic Meson SPI communication controller (SPICC)
  3 *
  4 * Copyright (C) BayLibre, SAS
  5 * Author: Neil Armstrong <narmstrong@baylibre.com>
  6 *
  7 * SPDX-License-Identifier: GPL-2.0+
  8 */
  9
 10#include <linux/bitfield.h>
 11#include <linux/clk.h>
 12#include <linux/clk-provider.h>
 13#include <linux/device.h>
 14#include <linux/io.h>
 15#include <linux/kernel.h>
 16#include <linux/module.h>
 17#include <linux/of.h>
 18#include <linux/of_device.h>
 19#include <linux/platform_device.h>
 20#include <linux/spi/spi.h>
 21#include <linux/types.h>
 22#include <linux/interrupt.h>
 23#include <linux/reset.h>
 24
 25/*
 26 * The Meson SPICC controller could support DMA based transfers, but is not
 27 * implemented by the vendor code, and while having the registers documentation
 28 * it has never worked on the GXL Hardware.
 29 * The PIO mode is the only mode implemented, and due to badly designed HW :
 30 * - all transfers are cutted in 16 words burst because the FIFO hangs on
 31 *   TX underflow, and there is no TX "Half-Empty" interrupt, so we go by
 32 *   FIFO max size chunk only
 33 * - CS management is dumb, and goes UP between every burst, so is really a
 34 *   "Data Valid" signal than a Chip Select, GPIO link should be used instead
 35 *   to have a CS go down over the full transfer
 36 */
 37
 38#define SPICC_MAX_BURST	128
 39
 40/* Register Map */
 41#define SPICC_RXDATA	0x00
 42
 43#define SPICC_TXDATA	0x04
 44
 45#define SPICC_CONREG	0x08
 46#define SPICC_ENABLE		BIT(0)
 47#define SPICC_MODE_MASTER	BIT(1)
 48#define SPICC_XCH		BIT(2)
 49#define SPICC_SMC		BIT(3)
 50#define SPICC_POL		BIT(4)
 51#define SPICC_PHA		BIT(5)
 52#define SPICC_SSCTL		BIT(6)
 53#define SPICC_SSPOL		BIT(7)
 54#define SPICC_DRCTL_MASK	GENMASK(9, 8)
 55#define SPICC_DRCTL_IGNORE	0
 56#define SPICC_DRCTL_FALLING	1
 57#define SPICC_DRCTL_LOWLEVEL	2
 58#define SPICC_CS_MASK		GENMASK(13, 12)
 59#define SPICC_DATARATE_MASK	GENMASK(18, 16)
 60#define SPICC_DATARATE_DIV4	0
 61#define SPICC_DATARATE_DIV8	1
 62#define SPICC_DATARATE_DIV16	2
 63#define SPICC_DATARATE_DIV32	3
 64#define SPICC_BITLENGTH_MASK	GENMASK(24, 19)
 65#define SPICC_BURSTLENGTH_MASK	GENMASK(31, 25)
 66
 67#define SPICC_INTREG	0x0c
 68#define SPICC_TE_EN	BIT(0) /* TX FIFO Empty Interrupt */
 69#define SPICC_TH_EN	BIT(1) /* TX FIFO Half-Full Interrupt */
 70#define SPICC_TF_EN	BIT(2) /* TX FIFO Full Interrupt */
 71#define SPICC_RR_EN	BIT(3) /* RX FIFO Ready Interrupt */
 72#define SPICC_RH_EN	BIT(4) /* RX FIFO Half-Full Interrupt */
 73#define SPICC_RF_EN	BIT(5) /* RX FIFO Full Interrupt */
 74#define SPICC_RO_EN	BIT(6) /* RX FIFO Overflow Interrupt */
 75#define SPICC_TC_EN	BIT(7) /* Transfert Complete Interrupt */
 76
 77#define SPICC_DMAREG	0x10
 78#define SPICC_DMA_ENABLE		BIT(0)
 79#define SPICC_TXFIFO_THRESHOLD_MASK	GENMASK(5, 1)
 80#define SPICC_RXFIFO_THRESHOLD_MASK	GENMASK(10, 6)
 81#define SPICC_READ_BURST_MASK		GENMASK(14, 11)
 82#define SPICC_WRITE_BURST_MASK		GENMASK(18, 15)
 83#define SPICC_DMA_URGENT		BIT(19)
 84#define SPICC_DMA_THREADID_MASK		GENMASK(25, 20)
 85#define SPICC_DMA_BURSTNUM_MASK		GENMASK(31, 26)
 86
 87#define SPICC_STATREG	0x14
 88#define SPICC_TE	BIT(0) /* TX FIFO Empty Interrupt */
 89#define SPICC_TH	BIT(1) /* TX FIFO Half-Full Interrupt */
 90#define SPICC_TF	BIT(2) /* TX FIFO Full Interrupt */
 91#define SPICC_RR	BIT(3) /* RX FIFO Ready Interrupt */
 92#define SPICC_RH	BIT(4) /* RX FIFO Half-Full Interrupt */
 93#define SPICC_RF	BIT(5) /* RX FIFO Full Interrupt */
 94#define SPICC_RO	BIT(6) /* RX FIFO Overflow Interrupt */
 95#define SPICC_TC	BIT(7) /* Transfert Complete Interrupt */
 96
 97#define SPICC_PERIODREG	0x18
 98#define SPICC_PERIOD	GENMASK(14, 0)	/* Wait cycles */
 99
100#define SPICC_TESTREG	0x1c
101#define SPICC_TXCNT_MASK	GENMASK(4, 0)	/* TX FIFO Counter */
102#define SPICC_RXCNT_MASK	GENMASK(9, 5)	/* RX FIFO Counter */
103#define SPICC_SMSTATUS_MASK	GENMASK(12, 10)	/* State Machine Status */
104#define SPICC_LBC_RO		BIT(13)	/* Loop Back Control Read-Only */
105#define SPICC_LBC_W1		BIT(14) /* Loop Back Control Write-Only */
106#define SPICC_SWAP_RO		BIT(14) /* RX FIFO Data Swap Read-Only */
107#define SPICC_SWAP_W1		BIT(15) /* RX FIFO Data Swap Write-Only */
108#define SPICC_DLYCTL_RO_MASK	GENMASK(20, 15) /* Delay Control Read-Only */
109#define SPICC_MO_DELAY_MASK	GENMASK(17, 16) /* Master Output Delay */
110#define SPICC_MO_NO_DELAY	0
111#define SPICC_MO_DELAY_1_CYCLE	1
112#define SPICC_MO_DELAY_2_CYCLE	2
113#define SPICC_MO_DELAY_3_CYCLE	3
114#define SPICC_MI_DELAY_MASK	GENMASK(19, 18) /* Master Input Delay */
115#define SPICC_MI_NO_DELAY	0
116#define SPICC_MI_DELAY_1_CYCLE	1
117#define SPICC_MI_DELAY_2_CYCLE	2
118#define SPICC_MI_DELAY_3_CYCLE	3
119#define SPICC_MI_CAP_DELAY_MASK	GENMASK(21, 20) /* Master Capture Delay */
120#define SPICC_CAP_AHEAD_2_CYCLE	0
121#define SPICC_CAP_AHEAD_1_CYCLE	1
122#define SPICC_CAP_NO_DELAY	2
123#define SPICC_CAP_DELAY_1_CYCLE	3
124#define SPICC_FIFORST_RO_MASK	GENMASK(22, 21) /* FIFO Softreset Read-Only */
125#define SPICC_FIFORST_W1_MASK	GENMASK(23, 22) /* FIFO Softreset Write-Only */
126
127#define SPICC_DRADDR	0x20	/* Read Address of DMA */
128
129#define SPICC_DWADDR	0x24	/* Write Address of DMA */
130
131#define SPICC_ENH_CTL0	0x38	/* Enhanced Feature */
132#define SPICC_ENH_CLK_CS_DELAY_MASK	GENMASK(15, 0)
133#define SPICC_ENH_DATARATE_MASK		GENMASK(23, 16)
134#define SPICC_ENH_DATARATE_EN		BIT(24)
135#define SPICC_ENH_MOSI_OEN		BIT(25)
136#define SPICC_ENH_CLK_OEN		BIT(26)
137#define SPICC_ENH_CS_OEN		BIT(27)
138#define SPICC_ENH_CLK_CS_DELAY_EN	BIT(28)
139#define SPICC_ENH_MAIN_CLK_AO		BIT(29)
140
141#define writel_bits_relaxed(mask, val, addr) \
142	writel_relaxed((readl_relaxed(addr) & ~(mask)) | (val), addr)
143
144struct meson_spicc_data {
145	unsigned int			max_speed_hz;
146	unsigned int			min_speed_hz;
147	unsigned int			fifo_size;
148	bool				has_oen;
149	bool				has_enhance_clk_div;
150	bool				has_pclk;
151};
152
153struct meson_spicc_device {
154	struct spi_master		*master;
155	struct platform_device		*pdev;
156	void __iomem			*base;
157	struct clk			*core;
158	struct clk			*pclk;
159	struct clk			*clk;
160	struct spi_message		*message;
161	struct spi_transfer		*xfer;
162	const struct meson_spicc_data	*data;
163	u8				*tx_buf;
164	u8				*rx_buf;
165	unsigned int			bytes_per_word;
166	unsigned long			tx_remain;
167	unsigned long			rx_remain;
168	unsigned long			xfer_remain;
169};
170
171static void meson_spicc_oen_enable(struct meson_spicc_device *spicc)
172{
173	u32 conf;
174
175	if (!spicc->data->has_oen)
176		return;
177
178	conf = readl_relaxed(spicc->base + SPICC_ENH_CTL0) |
179		SPICC_ENH_MOSI_OEN | SPICC_ENH_CLK_OEN | SPICC_ENH_CS_OEN;
180
181	writel_relaxed(conf, spicc->base + SPICC_ENH_CTL0);
182}
183
184static inline bool meson_spicc_txfull(struct meson_spicc_device *spicc)
185{
186	return !!FIELD_GET(SPICC_TF,
187			   readl_relaxed(spicc->base + SPICC_STATREG));
188}
189
190static inline bool meson_spicc_rxready(struct meson_spicc_device *spicc)
191{
192	return FIELD_GET(SPICC_RH | SPICC_RR | SPICC_RF,
193			 readl_relaxed(spicc->base + SPICC_STATREG));
194}
195
196static inline u32 meson_spicc_pull_data(struct meson_spicc_device *spicc)
197{
198	unsigned int bytes = spicc->bytes_per_word;
199	unsigned int byte_shift = 0;
200	u32 data = 0;
201	u8 byte;
202
203	while (bytes--) {
204		byte = *spicc->tx_buf++;
205		data |= (byte & 0xff) << byte_shift;
206		byte_shift += 8;
207	}
208
209	spicc->tx_remain--;
210	return data;
211}
212
213static inline void meson_spicc_push_data(struct meson_spicc_device *spicc,
214					 u32 data)
215{
216	unsigned int bytes = spicc->bytes_per_word;
217	unsigned int byte_shift = 0;
218	u8 byte;
219
220	while (bytes--) {
221		byte = (data >> byte_shift) & 0xff;
222		*spicc->rx_buf++ = byte;
223		byte_shift += 8;
224	}
225
226	spicc->rx_remain--;
227}
228
229static inline void meson_spicc_rx(struct meson_spicc_device *spicc)
230{
231	/* Empty RX FIFO */
232	while (spicc->rx_remain &&
233	       meson_spicc_rxready(spicc))
234		meson_spicc_push_data(spicc,
235				readl_relaxed(spicc->base + SPICC_RXDATA));
236}
237
238static inline void meson_spicc_tx(struct meson_spicc_device *spicc)
239{
240	/* Fill Up TX FIFO */
241	while (spicc->tx_remain &&
242	       !meson_spicc_txfull(spicc))
243		writel_relaxed(meson_spicc_pull_data(spicc),
244			       spicc->base + SPICC_TXDATA);
245}
246
247static inline void meson_spicc_setup_burst(struct meson_spicc_device *spicc)
248{
249
250	unsigned int burst_len = min_t(unsigned int,
251				       spicc->xfer_remain /
252				       spicc->bytes_per_word,
253				       spicc->data->fifo_size);
254	/* Setup Xfer variables */
255	spicc->tx_remain = burst_len;
256	spicc->rx_remain = burst_len;
257	spicc->xfer_remain -= burst_len * spicc->bytes_per_word;
258
259	/* Setup burst length */
260	writel_bits_relaxed(SPICC_BURSTLENGTH_MASK,
261			FIELD_PREP(SPICC_BURSTLENGTH_MASK,
262				burst_len - 1),
263			spicc->base + SPICC_CONREG);
264
265	/* Fill TX FIFO */
266	meson_spicc_tx(spicc);
267}
268
269static irqreturn_t meson_spicc_irq(int irq, void *data)
270{
271	struct meson_spicc_device *spicc = (void *) data;
272
273	writel_bits_relaxed(SPICC_TC, SPICC_TC, spicc->base + SPICC_STATREG);
274
275	/* Empty RX FIFO */
276	meson_spicc_rx(spicc);
277
278	if (!spicc->xfer_remain) {
279		/* Disable all IRQs */
280		writel(0, spicc->base + SPICC_INTREG);
281
282		spi_finalize_current_transfer(spicc->master);
283
284		return IRQ_HANDLED;
285	}
286
287	/* Setup burst */
288	meson_spicc_setup_burst(spicc);
289
290	/* Start burst */
291	writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG);
292
293	return IRQ_HANDLED;
294}
295
296static void meson_spicc_auto_io_delay(struct meson_spicc_device *spicc)
297{
298	u32 div, hz;
299	u32 mi_delay, cap_delay;
300	u32 conf;
301
302	if (spicc->data->has_enhance_clk_div) {
303		div = FIELD_GET(SPICC_ENH_DATARATE_MASK,
304				readl_relaxed(spicc->base + SPICC_ENH_CTL0));
305		div++;
306		div <<= 1;
307	} else {
308		div = FIELD_GET(SPICC_DATARATE_MASK,
309				readl_relaxed(spicc->base + SPICC_CONREG));
310		div += 2;
311		div = 1 << div;
312	}
313
314	mi_delay = SPICC_MI_NO_DELAY;
315	cap_delay = SPICC_CAP_AHEAD_2_CYCLE;
316	hz = clk_get_rate(spicc->clk);
317
318	if (hz >= 100000000)
319		cap_delay = SPICC_CAP_DELAY_1_CYCLE;
320	else if (hz >= 80000000)
321		cap_delay = SPICC_CAP_NO_DELAY;
322	else if (hz >= 40000000)
323		cap_delay = SPICC_CAP_AHEAD_1_CYCLE;
324	else if (div >= 16)
325		mi_delay = SPICC_MI_DELAY_3_CYCLE;
326	else if (div >= 8)
327		mi_delay = SPICC_MI_DELAY_2_CYCLE;
328	else if (div >= 6)
329		mi_delay = SPICC_MI_DELAY_1_CYCLE;
330
331	conf = readl_relaxed(spicc->base + SPICC_TESTREG);
332	conf &= ~(SPICC_MO_DELAY_MASK | SPICC_MI_DELAY_MASK
333		  | SPICC_MI_CAP_DELAY_MASK);
334	conf |= FIELD_PREP(SPICC_MI_DELAY_MASK, mi_delay);
335	conf |= FIELD_PREP(SPICC_MI_CAP_DELAY_MASK, cap_delay);
336	writel_relaxed(conf, spicc->base + SPICC_TESTREG);
337}
338
339static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc,
340				   struct spi_transfer *xfer)
341{
342	u32 conf, conf_orig;
343
344	/* Read original configuration */
345	conf = conf_orig = readl_relaxed(spicc->base + SPICC_CONREG);
346
347	/* Setup word width */
348	conf &= ~SPICC_BITLENGTH_MASK;
349	conf |= FIELD_PREP(SPICC_BITLENGTH_MASK,
350			   (spicc->bytes_per_word << 3) - 1);
351
352	/* Ignore if unchanged */
353	if (conf != conf_orig)
354		writel_relaxed(conf, spicc->base + SPICC_CONREG);
355
356	clk_set_rate(spicc->clk, xfer->speed_hz);
357
358	meson_spicc_auto_io_delay(spicc);
359
360	writel_relaxed(0, spicc->base + SPICC_DMAREG);
361}
362
363static void meson_spicc_reset_fifo(struct meson_spicc_device *spicc)
364{
365	if (spicc->data->has_oen)
366		writel_bits_relaxed(SPICC_ENH_MAIN_CLK_AO,
367				    SPICC_ENH_MAIN_CLK_AO,
368				    spicc->base + SPICC_ENH_CTL0);
369
370	writel_bits_relaxed(SPICC_FIFORST_W1_MASK, SPICC_FIFORST_W1_MASK,
371			    spicc->base + SPICC_TESTREG);
372
373	while (meson_spicc_rxready(spicc))
374		readl_relaxed(spicc->base + SPICC_RXDATA);
375
376	if (spicc->data->has_oen)
377		writel_bits_relaxed(SPICC_ENH_MAIN_CLK_AO, 0,
378				    spicc->base + SPICC_ENH_CTL0);
379}
380
381static int meson_spicc_transfer_one(struct spi_master *master,
382				    struct spi_device *spi,
383				    struct spi_transfer *xfer)
384{
385	struct meson_spicc_device *spicc = spi_master_get_devdata(master);
386
387	/* Store current transfer */
388	spicc->xfer = xfer;
389
390	/* Setup transfer parameters */
391	spicc->tx_buf = (u8 *)xfer->tx_buf;
392	spicc->rx_buf = (u8 *)xfer->rx_buf;
393	spicc->xfer_remain = xfer->len;
394
395	/* Pre-calculate word size */
396	spicc->bytes_per_word =
397	   DIV_ROUND_UP(spicc->xfer->bits_per_word, 8);
398
399	if (xfer->len % spicc->bytes_per_word)
400		return -EINVAL;
401
402	/* Setup transfer parameters */
403	meson_spicc_setup_xfer(spicc, xfer);
404
405	meson_spicc_reset_fifo(spicc);
406
407	/* Setup burst */
408	meson_spicc_setup_burst(spicc);
409
410	/* Start burst */
411	writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG);
412
413	/* Enable interrupts */
414	writel_relaxed(SPICC_TC_EN, spicc->base + SPICC_INTREG);
415
416	return 1;
417}
418
419static int meson_spicc_prepare_message(struct spi_master *master,
420				       struct spi_message *message)
421{
422	struct meson_spicc_device *spicc = spi_master_get_devdata(master);
423	struct spi_device *spi = message->spi;
424	u32 conf = 0;
425
426	/* Store current message */
427	spicc->message = message;
428
429	/* Enable Master */
430	conf |= SPICC_ENABLE;
431	conf |= SPICC_MODE_MASTER;
432
433	/* SMC = 0 */
434
435	/* Setup transfer mode */
436	if (spi->mode & SPI_CPOL)
437		conf |= SPICC_POL;
438	else
439		conf &= ~SPICC_POL;
440
441	if (spi->mode & SPI_CPHA)
442		conf |= SPICC_PHA;
443	else
444		conf &= ~SPICC_PHA;
445
446	/* SSCTL = 0 */
447
448	if (spi->mode & SPI_CS_HIGH)
449		conf |= SPICC_SSPOL;
450	else
451		conf &= ~SPICC_SSPOL;
452
453	if (spi->mode & SPI_READY)
454		conf |= FIELD_PREP(SPICC_DRCTL_MASK, SPICC_DRCTL_LOWLEVEL);
455	else
456		conf |= FIELD_PREP(SPICC_DRCTL_MASK, SPICC_DRCTL_IGNORE);
457
458	/* Select CS */
459	conf |= FIELD_PREP(SPICC_CS_MASK, spi->chip_select);
460
461	/* Default Clock rate core/4 */
462
463	/* Default 8bit word */
464	conf |= FIELD_PREP(SPICC_BITLENGTH_MASK, 8 - 1);
465
466	writel_relaxed(conf, spicc->base + SPICC_CONREG);
467
468	/* Setup no wait cycles by default */
469	writel_relaxed(0, spicc->base + SPICC_PERIODREG);
470
471	writel_bits_relaxed(SPICC_LBC_W1, 0, spicc->base + SPICC_TESTREG);
472
473	return 0;
474}
475
476static int meson_spicc_unprepare_transfer(struct spi_master *master)
477{
478	struct meson_spicc_device *spicc = spi_master_get_devdata(master);
479
480	/* Disable all IRQs */
481	writel(0, spicc->base + SPICC_INTREG);
482
483	device_reset_optional(&spicc->pdev->dev);
484
485	return 0;
486}
487
488static int meson_spicc_setup(struct spi_device *spi)
489{
490	if (!spi->controller_state)
491		spi->controller_state = spi_master_get_devdata(spi->master);
492
493	return 0;
494}
495
496static void meson_spicc_cleanup(struct spi_device *spi)
497{
498	spi->controller_state = NULL;
499}
500
501/*
502 * The Clock Mux
503 *            x-----------------x   x------------x    x------\
504 *        |---| pow2 fixed div  |---| pow2 div   |----|      |
505 *        |   x-----------------x   x------------x    |      |
506 * src ---|                                           | mux  |-- out
507 *        |   x-----------------x   x------------x    |      |
508 *        |---| enh fixed div   |---| enh div    |0---|      |
509 *            x-----------------x   x------------x    x------/
510 *
511 * Clk path for GX series:
512 *    src -> pow2 fixed div -> pow2 div -> out
513 *
514 * Clk path for AXG series:
515 *    src -> pow2 fixed div -> pow2 div -> mux -> out
516 *    src -> enh fixed div -> enh div -> mux -> out
517 *
518 * Clk path for G12A series:
519 *    pclk -> pow2 fixed div -> pow2 div -> mux -> out
520 *    pclk -> enh fixed div -> enh div -> mux -> out
521 */
522
523static int meson_spicc_clk_init(struct meson_spicc_device *spicc)
524{
525	struct device *dev = &spicc->pdev->dev;
526	struct clk_fixed_factor *pow2_fixed_div, *enh_fixed_div;
527	struct clk_divider *pow2_div, *enh_div;
528	struct clk_mux *mux;
529	struct clk_init_data init;
530	struct clk *clk;
531	struct clk_parent_data parent_data[2];
532	char name[64];
533
534	memset(&init, 0, sizeof(init));
535	memset(&parent_data, 0, sizeof(parent_data));
536
537	init.parent_data = parent_data;
538
539	/* algorithm for pow2 div: rate = freq / 4 / (2 ^ N) */
540
541	pow2_fixed_div = devm_kzalloc(dev, sizeof(*pow2_fixed_div), GFP_KERNEL);
542	if (!pow2_fixed_div)
543		return -ENOMEM;
544
545	snprintf(name, sizeof(name), "%s#pow2_fixed_div", dev_name(dev));
546	init.name = name;
547	init.ops = &clk_fixed_factor_ops;
548	init.flags = 0;
549	if (spicc->data->has_pclk)
550		parent_data[0].hw = __clk_get_hw(spicc->pclk);
551	else
552		parent_data[0].hw = __clk_get_hw(spicc->core);
553	init.num_parents = 1;
554
555	pow2_fixed_div->mult = 1,
556	pow2_fixed_div->div = 4,
557	pow2_fixed_div->hw.init = &init;
558
559	clk = devm_clk_register(dev, &pow2_fixed_div->hw);
560	if (WARN_ON(IS_ERR(clk)))
561		return PTR_ERR(clk);
562
563	pow2_div = devm_kzalloc(dev, sizeof(*pow2_div), GFP_KERNEL);
564	if (!pow2_div)
565		return -ENOMEM;
566
567	snprintf(name, sizeof(name), "%s#pow2_div", dev_name(dev));
568	init.name = name;
569	init.ops = &clk_divider_ops;
570	init.flags = CLK_SET_RATE_PARENT;
571	parent_data[0].hw = &pow2_fixed_div->hw;
572	init.num_parents = 1;
573
574	pow2_div->shift = 16,
575	pow2_div->width = 3,
576	pow2_div->flags = CLK_DIVIDER_POWER_OF_TWO,
577	pow2_div->reg = spicc->base + SPICC_CONREG;
578	pow2_div->hw.init = &init;
579
580	clk = devm_clk_register(dev, &pow2_div->hw);
581	if (WARN_ON(IS_ERR(clk)))
582		return PTR_ERR(clk);
583
584	if (!spicc->data->has_enhance_clk_div) {
585		spicc->clk = clk;
586		return 0;
587	}
588
589	/* algorithm for enh div: rate = freq / 2 / (N + 1) */
590
591	enh_fixed_div = devm_kzalloc(dev, sizeof(*enh_fixed_div), GFP_KERNEL);
592	if (!enh_fixed_div)
593		return -ENOMEM;
594
595	snprintf(name, sizeof(name), "%s#enh_fixed_div", dev_name(dev));
596	init.name = name;
597	init.ops = &clk_fixed_factor_ops;
598	init.flags = 0;
599	if (spicc->data->has_pclk)
600		parent_data[0].hw = __clk_get_hw(spicc->pclk);
601	else
602		parent_data[0].hw = __clk_get_hw(spicc->core);
603	init.num_parents = 1;
604
605	enh_fixed_div->mult = 1,
606	enh_fixed_div->div = 2,
607	enh_fixed_div->hw.init = &init;
608
609	clk = devm_clk_register(dev, &enh_fixed_div->hw);
610	if (WARN_ON(IS_ERR(clk)))
611		return PTR_ERR(clk);
612
613	enh_div = devm_kzalloc(dev, sizeof(*enh_div), GFP_KERNEL);
614	if (!enh_div)
615		return -ENOMEM;
616
617	snprintf(name, sizeof(name), "%s#enh_div", dev_name(dev));
618	init.name = name;
619	init.ops = &clk_divider_ops;
620	init.flags = CLK_SET_RATE_PARENT;
621	parent_data[0].hw = &enh_fixed_div->hw;
622	init.num_parents = 1;
623
624	enh_div->shift	= 16,
625	enh_div->width	= 8,
626	enh_div->reg = spicc->base + SPICC_ENH_CTL0;
627	enh_div->hw.init = &init;
628
629	clk = devm_clk_register(dev, &enh_div->hw);
630	if (WARN_ON(IS_ERR(clk)))
631		return PTR_ERR(clk);
632
633	mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
634	if (!mux)
635		return -ENOMEM;
636
637	snprintf(name, sizeof(name), "%s#sel", dev_name(dev));
638	init.name = name;
639	init.ops = &clk_mux_ops;
640	parent_data[0].hw = &pow2_div->hw;
641	parent_data[1].hw = &enh_div->hw;
642	init.num_parents = 2;
643	init.flags = CLK_SET_RATE_PARENT;
644
645	mux->mask = 0x1,
646	mux->shift = 24,
647	mux->reg = spicc->base + SPICC_ENH_CTL0;
648	mux->hw.init = &init;
649
650	spicc->clk = devm_clk_register(dev, &mux->hw);
651	if (WARN_ON(IS_ERR(spicc->clk)))
652		return PTR_ERR(spicc->clk);
653
654	return 0;
655}
656
657static int meson_spicc_probe(struct platform_device *pdev)
658{
659	struct spi_master *master;
660	struct meson_spicc_device *spicc;
661	int ret, irq;
662
663	master = spi_alloc_master(&pdev->dev, sizeof(*spicc));
664	if (!master) {
665		dev_err(&pdev->dev, "master allocation failed\n");
666		return -ENOMEM;
667	}
668	spicc = spi_master_get_devdata(master);
669	spicc->master = master;
670
671	spicc->data = of_device_get_match_data(&pdev->dev);
672	if (!spicc->data) {
673		dev_err(&pdev->dev, "failed to get match data\n");
674		ret = -EINVAL;
675		goto out_master;
676	}
677
678	spicc->pdev = pdev;
679	platform_set_drvdata(pdev, spicc);
680
681	spicc->base = devm_platform_ioremap_resource(pdev, 0);
682	if (IS_ERR(spicc->base)) {
683		dev_err(&pdev->dev, "io resource mapping failed\n");
684		ret = PTR_ERR(spicc->base);
685		goto out_master;
686	}
687
688	/* Set master mode and enable controller */
689	writel_relaxed(SPICC_ENABLE | SPICC_MODE_MASTER,
690		       spicc->base + SPICC_CONREG);
691
692	/* Disable all IRQs */
693	writel_relaxed(0, spicc->base + SPICC_INTREG);
694
695	irq = platform_get_irq(pdev, 0);
696	ret = devm_request_irq(&pdev->dev, irq, meson_spicc_irq,
697			       0, NULL, spicc);
698	if (ret) {
699		dev_err(&pdev->dev, "irq request failed\n");
700		goto out_master;
701	}
702
703	spicc->core = devm_clk_get(&pdev->dev, "core");
704	if (IS_ERR(spicc->core)) {
705		dev_err(&pdev->dev, "core clock request failed\n");
706		ret = PTR_ERR(spicc->core);
707		goto out_master;
708	}
709
710	if (spicc->data->has_pclk) {
711		spicc->pclk = devm_clk_get(&pdev->dev, "pclk");
712		if (IS_ERR(spicc->pclk)) {
713			dev_err(&pdev->dev, "pclk clock request failed\n");
714			ret = PTR_ERR(spicc->pclk);
715			goto out_master;
716		}
717	}
718
719	ret = clk_prepare_enable(spicc->core);
720	if (ret) {
721		dev_err(&pdev->dev, "core clock enable failed\n");
722		goto out_master;
723	}
724
725	ret = clk_prepare_enable(spicc->pclk);
726	if (ret) {
727		dev_err(&pdev->dev, "pclk clock enable failed\n");
728		goto out_master;
729	}
730
731	device_reset_optional(&pdev->dev);
732
733	master->num_chipselect = 4;
734	master->dev.of_node = pdev->dev.of_node;
735	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH;
736	master->bits_per_word_mask = SPI_BPW_MASK(32) |
737				     SPI_BPW_MASK(24) |
738				     SPI_BPW_MASK(16) |
739				     SPI_BPW_MASK(8);
740	master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);
741	master->min_speed_hz = spicc->data->min_speed_hz;
742	master->max_speed_hz = spicc->data->max_speed_hz;
743	master->setup = meson_spicc_setup;
744	master->cleanup = meson_spicc_cleanup;
745	master->prepare_message = meson_spicc_prepare_message;
746	master->unprepare_transfer_hardware = meson_spicc_unprepare_transfer;
747	master->transfer_one = meson_spicc_transfer_one;
748	master->use_gpio_descriptors = true;
749
750	meson_spicc_oen_enable(spicc);
751
752	ret = meson_spicc_clk_init(spicc);
753	if (ret) {
754		dev_err(&pdev->dev, "clock registration failed\n");
755		goto out_master;
756	}
757
758	ret = devm_spi_register_master(&pdev->dev, master);
759	if (ret) {
760		dev_err(&pdev->dev, "spi master registration failed\n");
761		goto out_clk;
762	}
763
764	return 0;
765
766out_clk:
767	clk_disable_unprepare(spicc->core);
768	clk_disable_unprepare(spicc->pclk);
769
770out_master:
771	spi_master_put(master);
772
773	return ret;
774}
775
776static int meson_spicc_remove(struct platform_device *pdev)
777{
778	struct meson_spicc_device *spicc = platform_get_drvdata(pdev);
779
780	/* Disable SPI */
781	writel(0, spicc->base + SPICC_CONREG);
782
783	clk_disable_unprepare(spicc->core);
784	clk_disable_unprepare(spicc->pclk);
785
786	return 0;
787}
788
789static const struct meson_spicc_data meson_spicc_gx_data = {
790	.max_speed_hz		= 30000000,
791	.min_speed_hz		= 325000,
792	.fifo_size		= 16,
793};
794
795static const struct meson_spicc_data meson_spicc_axg_data = {
796	.max_speed_hz		= 80000000,
797	.min_speed_hz		= 325000,
798	.fifo_size		= 16,
799	.has_oen		= true,
800	.has_enhance_clk_div	= true,
801};
802
803static const struct meson_spicc_data meson_spicc_g12a_data = {
804	.max_speed_hz		= 166666666,
805	.min_speed_hz		= 50000,
806	.fifo_size		= 15,
807	.has_oen		= true,
808	.has_enhance_clk_div	= true,
809	.has_pclk		= true,
810};
811
812static const struct of_device_id meson_spicc_of_match[] = {
813	{
814		.compatible	= "amlogic,meson-gx-spicc",
815		.data		= &meson_spicc_gx_data,
816	},
817	{
818		.compatible = "amlogic,meson-axg-spicc",
819		.data		= &meson_spicc_axg_data,
820	},
821	{
822		.compatible = "amlogic,meson-g12a-spicc",
823		.data		= &meson_spicc_g12a_data,
824	},
825	{ /* sentinel */ }
826};
827MODULE_DEVICE_TABLE(of, meson_spicc_of_match);
828
829static struct platform_driver meson_spicc_driver = {
830	.probe   = meson_spicc_probe,
831	.remove  = meson_spicc_remove,
832	.driver  = {
833		.name = "meson-spicc",
834		.of_match_table = of_match_ptr(meson_spicc_of_match),
835	},
836};
837
838module_platform_driver(meson_spicc_driver);
839
840MODULE_DESCRIPTION("Meson SPI Communication Controller driver");
841MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
842MODULE_LICENSE("GPL");