summaryrefslogtreecommitdiffstats
path: root/drivers/spi/spi-ingenic.c
blob: 03077a7e11c85979a5193da102c470e07840fc67 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
// SPDX-License-Identifier: GPL-2.0
/*
 * SPI bus driver for the Ingenic JZ47xx SoCs
 * Copyright (c) 2017-2021 Artur Rojek <contact@artur-rojek.eu>
 * Copyright (c) 2017-2021 Paul Cercueil <paul@crapouillou.net>
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>

#define REG_SSIDR	0x0
#define REG_SSICR0	0x4
#define REG_SSICR1	0x8
#define REG_SSISR	0xc
#define REG_SSIGR	0x18

#define REG_SSICR0_TENDIAN_LSB		BIT(19)
#define REG_SSICR0_RENDIAN_LSB		BIT(17)
#define REG_SSICR0_SSIE			BIT(15)
#define REG_SSICR0_LOOP			BIT(10)
#define REG_SSICR0_EACLRUN		BIT(7)
#define REG_SSICR0_FSEL			BIT(6)
#define REG_SSICR0_TFLUSH		BIT(2)
#define REG_SSICR0_RFLUSH		BIT(1)

#define REG_SSICR1_FRMHL_MASK		(BIT(31) | BIT(30))
#define REG_SSICR1_FRMHL		BIT(30)
#define REG_SSICR1_LFST			BIT(25)
#define REG_SSICR1_UNFIN		BIT(23)
#define REG_SSICR1_PHA			BIT(1)
#define REG_SSICR1_POL			BIT(0)

#define REG_SSISR_END			BIT(7)
#define REG_SSISR_BUSY			BIT(6)
#define REG_SSISR_TFF			BIT(5)
#define REG_SSISR_RFE			BIT(4)
#define REG_SSISR_RFHF			BIT(2)
#define REG_SSISR_UNDR			BIT(1)
#define REG_SSISR_OVER			BIT(0)

#define SPI_INGENIC_FIFO_SIZE		128u

struct jz_soc_info {
	u32 bits_per_word_mask;
	struct reg_field flen_field;
	bool has_trendian;
};

struct ingenic_spi {
	const struct jz_soc_info *soc_info;
	struct clk *clk;
	struct resource *mem_res;

	struct regmap *map;
	struct regmap_field *flen_field;
};

static int spi_ingenic_wait(struct ingenic_spi *priv,
			    unsigned long mask,
			    bool condition)
{
	unsigned int val;

	return regmap_read_poll_timeout(priv->map, REG_SSISR, val,
					!!(val & mask) == condition,
					100, 10000);
}

static void spi_ingenic_set_cs(struct spi_device *spi, bool disable)
{
	struct ingenic_spi *priv = spi_controller_get_devdata(spi->controller);

	if (disable) {
		regmap_clear_bits(priv->map, REG_SSICR1, REG_SSICR1_UNFIN);
		regmap_clear_bits(priv->map, REG_SSISR,
				  REG_SSISR_UNDR | REG_SSISR_OVER);

		spi_ingenic_wait(priv, REG_SSISR_END, true);
	} else {
		regmap_set_bits(priv->map, REG_SSICR1, REG_SSICR1_UNFIN);
	}

	regmap_set_bits(priv->map, REG_SSICR0,
			REG_SSICR0_RFLUSH | REG_SSICR0_TFLUSH);
}

static void spi_ingenic_prepare_transfer(struct ingenic_spi *priv,
					 struct spi_device *spi,
					 struct spi_transfer *xfer)
{
	unsigned long clk_hz = clk_get_rate(priv->clk);
	u32 cdiv, speed_hz = xfer->speed_hz ?: spi->max_speed_hz,
	    bits_per_word = xfer->bits_per_word ?: spi->bits_per_word;

	cdiv = clk_hz / (speed_hz * 2);
	cdiv = clamp(cdiv, 1u, 0x100u) - 1;

	regmap_write(priv->map, REG_SSIGR, cdiv);

	regmap_field_write(priv->flen_field, bits_per_word - 2);
}

static void spi_ingenic_finalize_transfer(void *controller)
{
	spi_finalize_current_transfer(controller);
}

static struct dma_async_tx_descriptor *
spi_ingenic_prepare_dma(struct spi_controller *ctlr, struct dma_chan *chan,
			struct sg_table *sg, enum dma_transfer_direction dir,
			unsigned int bits)
{
	struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
	struct dma_slave_config cfg = {
		.direction = dir,
		.src_addr = priv->mem_res->start + REG_SSIDR,
		.dst_addr = priv->mem_res->start + REG_SSIDR,
	};
	struct dma_async_tx_descriptor *desc;
	dma_cookie_t cookie;
	int ret;

	if (bits > 16) {
		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
		cfg.src_maxburst = cfg.dst_maxburst = 4;
	} else if (bits > 8) {
		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
		cfg.src_maxburst = cfg.dst_maxburst = 2;
	} else {
		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
		cfg.src_maxburst = cfg.dst_maxburst = 1;
	}

	ret = dmaengine_slave_config(chan, &cfg);
	if (ret)
		return ERR_PTR(ret);

	desc = dmaengine_prep_slave_sg(chan, sg->sgl, sg->nents, dir,
				       DMA_PREP_INTERRUPT);
	if (!desc)
		return ERR_PTR(-ENOMEM);

	if (dir == DMA_DEV_TO_MEM) {
		desc->callback = spi_ingenic_finalize_transfer;
		desc->callback_param = ctlr;
	}

	cookie = dmaengine_submit(desc);

	ret = dma_submit_error(cookie);
	if (ret) {
		dmaengine_desc_free(desc);
		return ERR_PTR(ret);
	}

	return desc;
}

static int spi_ingenic_dma_tx(struct spi_controller *ctlr,
			      struct spi_transfer *xfer, unsigned int bits)
{
	struct dma_async_tx_descriptor *rx_desc, *tx_desc;

	rx_desc = spi_ingenic_prepare_dma(ctlr, ctlr->dma_rx,
					  &xfer->rx_sg, DMA_DEV_TO_MEM, bits);
	if (IS_ERR(rx_desc))
		return PTR_ERR(rx_desc);

	tx_desc = spi_ingenic_prepare_dma(ctlr, ctlr->dma_tx,
					  &xfer->tx_sg, DMA_MEM_TO_DEV, bits);
	if (IS_ERR(tx_desc)) {
		dmaengine_terminate_async(ctlr->dma_rx);
		dmaengine_desc_free(rx_desc);
		return PTR_ERR(tx_desc);
	}

	dma_async_issue_pending(ctlr->dma_rx);
	dma_async_issue_pending(ctlr->dma_tx);

	return 1;
}

#define SPI_INGENIC_TX(x)							\
static int spi_ingenic_tx##x(struct ingenic_spi *priv,				\
			     struct spi_transfer *xfer)				\
{										\
	unsigned int count = xfer->len / (x / 8);				\
	unsigned int prefill = min(count, SPI_INGENIC_FIFO_SIZE);		\
	const u##x *tx_buf = xfer->tx_buf;					\
	u##x *rx_buf = xfer->rx_buf;						\
	unsigned int i, val;							\
	int err;								\
										\
	/* Fill up the TX fifo */						\
	for (i = 0; i < prefill; i++) {						\
		val = tx_buf ? tx_buf[i] : 0;					\
										\
		regmap_write(priv->map, REG_SSIDR, val);			\
	}									\
										\
	for (i = 0; i < count; i++) {						\
		err = spi_ingenic_wait(priv, REG_SSISR_RFE, false);		\
		if (err)							\
			return err;						\
										\
		regmap_read(priv->map, REG_SSIDR, &val);			\
		if (rx_buf)							\
			rx_buf[i] = val;					\
										\
		if (i < count - prefill) {					\
			val = tx_buf ? tx_buf[i + prefill] : 0;			\
										\
			regmap_write(priv->map, REG_SSIDR, val);		\
		}								\
	}									\
										\
	return 0;								\
}
SPI_INGENIC_TX(8)
SPI_INGENIC_TX(16)
SPI_INGENIC_TX(32)
#undef SPI_INGENIC_TX

static int spi_ingenic_transfer_one(struct spi_controller *ctlr,
				    struct spi_device *spi,
				    struct spi_transfer *xfer)
{
	struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
	unsigned int bits = xfer->bits_per_word ?: spi->bits_per_word;
	bool can_dma = ctlr->can_dma && ctlr->can_dma(ctlr, spi, xfer);

	spi_ingenic_prepare_transfer(priv, spi, xfer);

	if (ctlr->cur_msg_mapped && can_dma)
		return spi_ingenic_dma_tx(ctlr, xfer, bits);

	if (bits > 16)
		return spi_ingenic_tx32(priv, xfer);

	if (bits > 8)
		return spi_ingenic_tx16(priv, xfer);

	return spi_ingenic_tx8(priv, xfer);
}

static int spi_ingenic_prepare_message(struct spi_controller *ctlr,
				       struct spi_message *message)
{
	struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
	struct spi_device *spi = message->spi;
	unsigned int cs = REG_SSICR1_FRMHL << spi->chip_select;
	unsigned int ssicr0_mask = REG_SSICR0_LOOP | REG_SSICR0_FSEL;
	unsigned int ssicr1_mask = REG_SSICR1_PHA | REG_SSICR1_POL | cs;
	unsigned int ssicr0 = 0, ssicr1 = 0;

	if (priv->soc_info->has_trendian) {
		ssicr0_mask |= REG_SSICR0_RENDIAN_LSB | REG_SSICR0_TENDIAN_LSB;

		if (spi->mode & SPI_LSB_FIRST)
			ssicr0 |= REG_SSICR0_RENDIAN_LSB | REG_SSICR0_TENDIAN_LSB;
	} else {
		ssicr1_mask |= REG_SSICR1_LFST;

		if (spi->mode & SPI_LSB_FIRST)
			ssicr1 |= REG_SSICR1_LFST;
	}

	if (spi->mode & SPI_LOOP)
		ssicr0 |= REG_SSICR0_LOOP;
	if (spi->chip_select)
		ssicr0 |= REG_SSICR0_FSEL;

	if (spi->mode & SPI_CPHA)
		ssicr1 |= REG_SSICR1_PHA;
	if (spi->mode & SPI_CPOL)
		ssicr1 |= REG_SSICR1_POL;
	if (spi->mode & SPI_CS_HIGH)
		ssicr1 |= cs;

	regmap_update_bits(priv->map, REG_SSICR0, ssicr0_mask, ssicr0);
	regmap_update_bits(priv->map, REG_SSICR1, ssicr1_mask, ssicr1);

	return 0;
}

static int spi_ingenic_prepare_hardware(struct spi_controller *ctlr)
{
	struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
	int ret;

	ret = clk_prepare_enable(priv->clk);
	if (ret)
		return ret;

	regmap_write(priv->map, REG_SSICR0, REG_SSICR0_EACLRUN);
	regmap_write(priv->map, REG_SSICR1, 0);
	regmap_write(priv->map, REG_SSISR, 0);
	regmap_set_bits(priv->map, REG_SSICR0, REG_SSICR0_SSIE);

	return 0;
}

static int spi_ingenic_unprepare_hardware(struct spi_controller *ctlr)
{
	struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);

	regmap_clear_bits(priv->map, REG_SSICR0, REG_SSICR0_SSIE);

	clk_disable_unprepare(priv->clk);

	return 0;
}

static bool spi_ingenic_can_dma(struct spi_controller *ctlr,
				struct spi_device *spi,
				struct spi_transfer *xfer)
{
	struct dma_slave_caps caps;
	int ret;

	ret = dma_get_slave_caps(ctlr->dma_tx, &caps);
	if (ret) {
		dev_err(&spi->dev, "Unable to get slave caps: %d\n", ret);
		return false;
	}

	return !caps.max_sg_burst ||
		xfer->len <= caps.max_sg_burst * SPI_INGENIC_FIFO_SIZE;
}

static int spi_ingenic_request_dma(struct spi_controller *ctlr,
				   struct device *dev)
{
	ctlr->dma_tx = dma_request_slave_channel(dev, "tx");
	if (!ctlr->dma_tx)
		return -ENODEV;

	ctlr->dma_rx = dma_request_slave_channel(dev, "rx");

	if (!ctlr->dma_rx)
		return -ENODEV;

	ctlr->can_dma = spi_ingenic_can_dma;

	return 0;
}

static void spi_ingenic_release_dma(void *data)
{
	struct spi_controller *ctlr = data;

	if (ctlr->dma_tx)
		dma_release_channel(ctlr->dma_tx);
	if (ctlr->dma_rx)
		dma_release_channel(ctlr->dma_rx);
}

static const struct regmap_config spi_ingenic_regmap_config = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
	.max_register = REG_SSIGR,
};

static int spi_ingenic_probe(struct platform_device *pdev)
{
	const struct jz_soc_info *pdata;
	struct device *dev = &pdev->dev;
	struct spi_controller *ctlr;
	struct ingenic_spi *priv;
	void __iomem *base;
	int ret;

	pdata = of_device_get_match_data(dev);
	if (!pdata) {
		dev_err(dev, "Missing platform data.\n");
		return -EINVAL;
	}

	ctlr = devm_spi_alloc_master(dev, sizeof(*priv));
	if (!ctlr) {
		dev_err(dev, "Unable to allocate SPI controller.\n");
		return -ENOMEM;
	}

	priv = spi_controller_get_devdata(ctlr);
	priv->soc_info = pdata;

	priv->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(priv->clk)) {
		return dev_err_probe(dev, PTR_ERR(priv->clk),
				     "Unable to get clock.\n");
	}

	base = devm_platform_get_and_ioremap_resource(pdev, 0, &priv->mem_res);
	if (IS_ERR(base))
		return PTR_ERR(base);

	priv->map = devm_regmap_init_mmio(dev, base, &spi_ingenic_regmap_config);
	if (IS_ERR(priv->map))
		return PTR_ERR(priv->map);

	priv->flen_field = devm_regmap_field_alloc(dev, priv->map,
						   pdata->flen_field);
	if (IS_ERR(priv->flen_field))
		return PTR_ERR(priv->flen_field);

	platform_set_drvdata(pdev, ctlr);

	ctlr->prepare_transfer_hardware = spi_ingenic_prepare_hardware;
	ctlr->unprepare_transfer_hardware = spi_ingenic_unprepare_hardware;
	ctlr->prepare_message = spi_ingenic_prepare_message;
	ctlr->set_cs = spi_ingenic_set_cs;
	ctlr->transfer_one = spi_ingenic_transfer_one;
	ctlr->mode_bits = SPI_MODE_3 | SPI_LSB_FIRST | SPI_LOOP | SPI_CS_HIGH;
	ctlr->flags = SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX;
	ctlr->max_dma_len = SPI_INGENIC_FIFO_SIZE;
	ctlr->bits_per_word_mask = pdata->bits_per_word_mask;
	ctlr->min_speed_hz = 7200;
	ctlr->max_speed_hz = 54000000;
	ctlr->num_chipselect = 2;
	ctlr->dev.of_node = pdev->dev.of_node;

	if (spi_ingenic_request_dma(ctlr, dev))
		dev_warn(dev, "DMA not available.\n");

	ret = devm_add_action_or_reset(dev, spi_ingenic_release_dma, ctlr);
	if (ret) {
		dev_err(dev, "Unable to add action.\n");
		return ret;
	}

	ret = devm_spi_register_controller(dev, ctlr);
	if (ret)
		dev_err(dev, "Unable to register SPI controller.\n");

	return ret;
}

static const struct jz_soc_info jz4750_soc_info = {
	.bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 17),
	.flen_field = REG_FIELD(REG_SSICR1, 4, 7),
	.has_trendian = false,
};

static const struct jz_soc_info jz4780_soc_info = {
	.bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 32),
	.flen_field = REG_FIELD(REG_SSICR1, 3, 7),
	.has_trendian = true,
};

static const struct of_device_id spi_ingenic_of_match[] = {
	{ .compatible = "ingenic,jz4750-spi", .data = &jz4750_soc_info },
	{ .compatible = "ingenic,jz4780-spi", .data = &jz4780_soc_info },
	{}
};
MODULE_DEVICE_TABLE(of, spi_ingenic_of_match);

static struct platform_driver spi_ingenic_driver = {
	.driver = {
		.name = "spi-ingenic",
		.of_match_table = spi_ingenic_of_match,
	},
	.probe = spi_ingenic_probe,
};

module_platform_driver(spi_ingenic_driver);
MODULE_DESCRIPTION("SPI bus driver for the Ingenic JZ47xx SoCs");
MODULE_AUTHOR("Artur Rojek <contact@artur-rojek.eu>");
MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
MODULE_LICENSE("GPL");