summaryrefslogtreecommitdiff
path: root/drivers/spi/tegra114_spi.c
blob: bb34b20f545531d28e6b50b13cbeb1b80116e4ce (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
// SPDX-License-Identifier: GPL-2.0
/*
 * NVIDIA Tegra SPI controller (T114 and later)
 *
 * Copyright (c) 2010-2013 NVIDIA Corporation
 */

#include <common.h>
#include <dm.h>
#include <time.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch-tegra/clk_rst.h>
#include <spi.h>
#include "tegra_spi.h"

/* COMMAND1 */
#define SPI_CMD1_GO			BIT(31)
#define SPI_CMD1_M_S			BIT(30)
#define SPI_CMD1_MODE_MASK		GENMASK(1, 0)
#define SPI_CMD1_MODE_SHIFT		28
#define SPI_CMD1_CS_SEL_MASK		GENMASK(1, 0)
#define SPI_CMD1_CS_SEL_SHIFT		26
#define SPI_CMD1_CS_POL_INACTIVE3	BIT(25)
#define SPI_CMD1_CS_POL_INACTIVE2	BIT(24)
#define SPI_CMD1_CS_POL_INACTIVE1	BIT(23)
#define SPI_CMD1_CS_POL_INACTIVE0	BIT(22)
#define SPI_CMD1_CS_SW_HW		BIT(21)
#define SPI_CMD1_CS_SW_VAL		BIT(20)
#define SPI_CMD1_IDLE_SDA_MASK		GENMASK(1, 0)
#define SPI_CMD1_IDLE_SDA_SHIFT		18
#define SPI_CMD1_BIDIR			BIT(17)
#define SPI_CMD1_LSBI_FE		BIT(16)
#define SPI_CMD1_LSBY_FE		BIT(15)
#define SPI_CMD1_BOTH_EN_BIT		BIT(14)
#define SPI_CMD1_BOTH_EN_BYTE		BIT(13)
#define SPI_CMD1_RX_EN			BIT(12)
#define SPI_CMD1_TX_EN			BIT(11)
#define SPI_CMD1_PACKED			BIT(5)
#define SPI_CMD1_BIT_LEN_MASK		GENMASK(4, 0)
#define SPI_CMD1_BIT_LEN_SHIFT		0

/* COMMAND2 */
#define SPI_CMD2_TX_CLK_TAP_DELAY	BIT(6)
#define SPI_CMD2_TX_CLK_TAP_DELAY_MASK	GENMASK(11, 6)
#define SPI_CMD2_RX_CLK_TAP_DELAY	BIT(0)
#define SPI_CMD2_RX_CLK_TAP_DELAY_MASK	GENMASK(5, 0)

/* TRANSFER STATUS */
#define SPI_XFER_STS_RDY		BIT(30)

/* FIFO STATUS */
#define SPI_FIFO_STS_CS_INACTIVE	BIT(31)
#define SPI_FIFO_STS_FRAME_END		BIT(30)
#define SPI_FIFO_STS_RX_FIFO_FLUSH	BIT(15)
#define SPI_FIFO_STS_TX_FIFO_FLUSH	BIT(14)
#define SPI_FIFO_STS_ERR		BIT(8)
#define SPI_FIFO_STS_TX_FIFO_OVF	BIT(7)
#define SPI_FIFO_STS_TX_FIFO_UNR	BIT(6)
#define SPI_FIFO_STS_RX_FIFO_OVF	BIT(5)
#define SPI_FIFO_STS_RX_FIFO_UNR	BIT(4)
#define SPI_FIFO_STS_TX_FIFO_FULL	BIT(3)
#define SPI_FIFO_STS_TX_FIFO_EMPTY	BIT(2)
#define SPI_FIFO_STS_RX_FIFO_FULL	BIT(1)
#define SPI_FIFO_STS_RX_FIFO_EMPTY	BIT(0)

#define SPI_TIMEOUT		1000
#define TEGRA_SPI_MAX_FREQ	52000000

struct spi_regs {
	u32 command1;	/* 000:SPI_COMMAND1 register */
	u32 command2;	/* 004:SPI_COMMAND2 register */
	u32 timing1;	/* 008:SPI_CS_TIM1 register */
	u32 timing2;	/* 00c:SPI_CS_TIM2 register */
	u32 xfer_status;/* 010:SPI_TRANS_STATUS register */
	u32 fifo_status;/* 014:SPI_FIFO_STATUS register */
	u32 tx_data;	/* 018:SPI_TX_DATA register */
	u32 rx_data;	/* 01c:SPI_RX_DATA register */
	u32 dma_ctl;	/* 020:SPI_DMA_CTL register */
	u32 dma_blk;	/* 024:SPI_DMA_BLK register */
	u32 rsvd[56];	/* 028-107 reserved */
	u32 tx_fifo;	/* 108:SPI_FIFO1 register */
	u32 rsvd2[31];	/* 10c-187 reserved */
	u32 rx_fifo;	/* 188:SPI_FIFO2 register */
	u32 spare_ctl;	/* 18c:SPI_SPARE_CTRL register */
};

struct tegra114_spi_priv {
	struct spi_regs *regs;
	unsigned int freq;
	unsigned int mode;
	int periph_id;
	int valid;
	int last_transaction_us;
};

static int tegra114_spi_ofdata_to_platdata(struct udevice *bus)
{
	struct tegra_spi_platdata *plat = bus->platdata;

	plat->base = dev_read_addr(bus);
	plat->periph_id = clock_decode_periph_id(bus);

	if (plat->periph_id == PERIPH_ID_NONE) {
		debug("%s: could not decode periph id %d\n", __func__,
		      plat->periph_id);
		return -FDT_ERR_NOTFOUND;
	}

	/* Use 500KHz as a suitable default */
	plat->frequency = dev_read_u32_default(bus, "spi-max-frequency",
					       500000);
	plat->deactivate_delay_us = dev_read_u32_default(bus,
						"spi-deactivate-delay", 0);
	debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
	      __func__, plat->base, plat->periph_id, plat->frequency,
	      plat->deactivate_delay_us);

	return 0;
}

static int tegra114_spi_probe(struct udevice *bus)
{
	struct tegra_spi_platdata *plat = dev_get_platdata(bus);
	struct tegra114_spi_priv *priv = dev_get_priv(bus);
	struct spi_regs *regs;
	ulong rate;

	priv->regs = (struct spi_regs *)plat->base;
	regs = priv->regs;

	priv->last_transaction_us = timer_get_us();
	priv->freq = plat->frequency;
	priv->periph_id = plat->periph_id;

	/*
	 * Change SPI clock to correct frequency, PLLP_OUT0 source, falling
	 * back to the oscillator if that is too fast.
	 */
	rate = clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH,
				      priv->freq);
	if (rate > priv->freq + 100000) {
		rate = clock_start_periph_pll(priv->periph_id, CLOCK_ID_OSC,
					      priv->freq);
		if (rate != priv->freq) {
			printf("Warning: SPI '%s' requested clock %u, actual clock %lu\n",
			       bus->name, priv->freq, rate);
		}
	}
	udelay(plat->deactivate_delay_us);

	/* Clear stale status here */
	setbits_le32(&regs->fifo_status,
		     SPI_FIFO_STS_ERR		|
		     SPI_FIFO_STS_TX_FIFO_OVF	|
		     SPI_FIFO_STS_TX_FIFO_UNR	|
		     SPI_FIFO_STS_RX_FIFO_OVF	|
		     SPI_FIFO_STS_RX_FIFO_UNR	|
		     SPI_FIFO_STS_TX_FIFO_FULL	|
		     SPI_FIFO_STS_TX_FIFO_EMPTY	|
		     SPI_FIFO_STS_RX_FIFO_FULL	|
		     SPI_FIFO_STS_RX_FIFO_EMPTY);
	debug("%s: FIFO STATUS = %08x\n", __func__, readl(&regs->fifo_status));

	setbits_le32(&priv->regs->command1, SPI_CMD1_M_S | SPI_CMD1_CS_SW_HW |
		     (priv->mode << SPI_CMD1_MODE_SHIFT) | SPI_CMD1_CS_SW_VAL);
	debug("%s: COMMAND1 = %08x\n", __func__, readl(&regs->command1));

	return 0;
}

/**
 * Activate the CS by driving it LOW
 *
 * @param slave	Pointer to spi_slave to which controller has to
 *		communicate with
 */
static void spi_cs_activate(struct udevice *dev)
{
	struct udevice *bus = dev->parent;
	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
	struct tegra114_spi_priv *priv = dev_get_priv(bus);

	/* If it's too soon to do another transaction, wait */
	if (pdata->deactivate_delay_us &&
	    priv->last_transaction_us) {
		ulong delay_us;		/* The delay completed so far */
		delay_us = timer_get_us() - priv->last_transaction_us;
		if (delay_us < pdata->deactivate_delay_us)
			udelay(pdata->deactivate_delay_us - delay_us);
	}

	clrbits_le32(&priv->regs->command1, SPI_CMD1_CS_SW_VAL);
}

/**
 * Deactivate the CS by driving it HIGH
 *
 * @param slave	Pointer to spi_slave to which controller has to
 *		communicate with
 */
static void spi_cs_deactivate(struct udevice *dev)
{
	struct udevice *bus = dev->parent;
	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
	struct tegra114_spi_priv *priv = dev_get_priv(bus);

	setbits_le32(&priv->regs->command1, SPI_CMD1_CS_SW_VAL);

	/* Remember time of this transaction so we can honour the bus delay */
	if (pdata->deactivate_delay_us)
		priv->last_transaction_us = timer_get_us();

	debug("Deactivate CS, bus '%s'\n", bus->name);
}

static int tegra114_spi_xfer(struct udevice *dev, unsigned int bitlen,
			     const void *data_out, void *data_in,
			     unsigned long flags)
{
	struct udevice *bus = dev->parent;
	struct tegra114_spi_priv *priv = dev_get_priv(bus);
	struct spi_regs *regs = priv->regs;
	u32 reg, tmpdout, tmpdin = 0;
	const u8 *dout = data_out;
	u8 *din = data_in;
	int num_bytes;
	int ret;

	debug("%s: slave %u:%u dout %p din %p bitlen %u\n",
	      __func__, bus->seq, spi_chip_select(dev), dout, din, bitlen);
	if (bitlen % 8)
		return -1;
	num_bytes = bitlen / 8;

	ret = 0;

	if (flags & SPI_XFER_BEGIN)
		spi_cs_activate(dev);

	/* clear all error status bits */
	reg = readl(&regs->fifo_status);
	writel(reg, &regs->fifo_status);

	clrsetbits_le32(&regs->command1, SPI_CMD1_CS_SW_VAL,
			SPI_CMD1_RX_EN | SPI_CMD1_TX_EN | SPI_CMD1_LSBY_FE |
			(spi_chip_select(dev) << SPI_CMD1_CS_SEL_SHIFT));

	/* set xfer size to 1 block (32 bits) */
	writel(0, &regs->dma_blk);

	/* handle data in 32-bit chunks */
	while (num_bytes > 0) {
		int bytes;
		int tm, i;

		tmpdout = 0;
		bytes = (num_bytes > 4) ?  4 : num_bytes;

		if (dout != NULL) {
			for (i = 0; i < bytes; ++i)
				tmpdout = (tmpdout << 8) | dout[i];
			dout += bytes;
		}

		num_bytes -= bytes;

		/* clear ready bit */
		setbits_le32(&regs->xfer_status, SPI_XFER_STS_RDY);

		clrsetbits_le32(&regs->command1,
				SPI_CMD1_BIT_LEN_MASK << SPI_CMD1_BIT_LEN_SHIFT,
				(bytes * 8 - 1) << SPI_CMD1_BIT_LEN_SHIFT);
		writel(tmpdout, &regs->tx_fifo);
		setbits_le32(&regs->command1, SPI_CMD1_GO);

		/*
		 * Wait for SPI transmit FIFO to empty, or to time out.
		 * The RX FIFO status will be read and cleared last
		 */
		for (tm = 0; tm < SPI_TIMEOUT; ++tm) {
			u32 fifo_status, xfer_status;

			xfer_status = readl(&regs->xfer_status);
			if (!(xfer_status & SPI_XFER_STS_RDY))
				continue;

			fifo_status = readl(&regs->fifo_status);
			if (fifo_status & SPI_FIFO_STS_ERR) {
				debug("%s: got a fifo error: ", __func__);
				if (fifo_status & SPI_FIFO_STS_TX_FIFO_OVF)
					debug("tx FIFO overflow ");
				if (fifo_status & SPI_FIFO_STS_TX_FIFO_UNR)
					debug("tx FIFO underrun ");
				if (fifo_status & SPI_FIFO_STS_RX_FIFO_OVF)
					debug("rx FIFO overflow ");
				if (fifo_status & SPI_FIFO_STS_RX_FIFO_UNR)
					debug("rx FIFO underrun ");
				if (fifo_status & SPI_FIFO_STS_TX_FIFO_FULL)
					debug("tx FIFO full ");
				if (fifo_status & SPI_FIFO_STS_TX_FIFO_EMPTY)
					debug("tx FIFO empty ");
				if (fifo_status & SPI_FIFO_STS_RX_FIFO_FULL)
					debug("rx FIFO full ");
				if (fifo_status & SPI_FIFO_STS_RX_FIFO_EMPTY)
					debug("rx FIFO empty ");
				debug("\n");
				break;
			}

			if (!(fifo_status & SPI_FIFO_STS_RX_FIFO_EMPTY)) {
				tmpdin = readl(&regs->rx_fifo);

				/* swap bytes read in */
				if (din != NULL) {
					for (i = bytes - 1; i >= 0; --i) {
						din[i] = tmpdin & 0xff;
						tmpdin >>= 8;
					}
					din += bytes;
				}

				/* We can exit when we've had both RX and TX */
				break;
			}
		}

		if (tm >= SPI_TIMEOUT)
			ret = tm;

		/* clear ACK RDY, etc. bits */
		writel(readl(&regs->fifo_status), &regs->fifo_status);
	}

	if (flags & SPI_XFER_END)
		spi_cs_deactivate(dev);

	debug("%s: transfer ended. Value=%08x, fifo_status = %08x\n",
	      __func__, tmpdin, readl(&regs->fifo_status));

	if (ret) {
		printf("%s: timeout during SPI transfer, tm %d\n",
		       __func__, ret);
		return -1;
	}

	return ret;
}

static int tegra114_spi_set_speed(struct udevice *bus, uint speed)
{
	struct tegra_spi_platdata *plat = bus->platdata;
	struct tegra114_spi_priv *priv = dev_get_priv(bus);

	if (speed > plat->frequency)
		speed = plat->frequency;
	priv->freq = speed;
	debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);

	return 0;
}

static int tegra114_spi_set_mode(struct udevice *bus, uint mode)
{
	struct tegra114_spi_priv *priv = dev_get_priv(bus);

	priv->mode = mode;
	debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);

	return 0;
}

static const struct dm_spi_ops tegra114_spi_ops = {
	.xfer		= tegra114_spi_xfer,
	.set_speed	= tegra114_spi_set_speed,
	.set_mode	= tegra114_spi_set_mode,
	/*
	 * cs_info is not needed, since we require all chip selects to be
	 * in the device tree explicitly
	 */
};

static const struct udevice_id tegra114_spi_ids[] = {
	{ .compatible = "nvidia,tegra114-spi" },
	{ }
};

U_BOOT_DRIVER(tegra114_spi) = {
	.name	= "tegra114_spi",
	.id	= UCLASS_SPI,
	.of_match = tegra114_spi_ids,
	.ops	= &tegra114_spi_ops,
	.ofdata_to_platdata = tegra114_spi_ofdata_to_platdata,
	.platdata_auto_alloc_size = sizeof(struct tegra_spi_platdata),
	.priv_auto_alloc_size = sizeof(struct tegra114_spi_priv),
	.probe	= tegra114_spi_probe,
};