summaryrefslogtreecommitdiffstats
path: root/drivers/spi/spi-dw-mmio.c
blob: cc74cbe03431d8a9e62275927620c3f5addacd57 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Memory-mapped interface driver for DW SPI Core
 *
 * Copyright (c) 2010, Octasic semiconductor.
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/scatterlist.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/acpi.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/reset.h>

#include "spi-dw.h"

#define DRIVER_NAME "dw_spi_mmio"

struct dw_spi_mmio {
	struct dw_spi  dws;
	struct clk     *clk;
	struct clk     *pclk;
	void           *priv;
	struct reset_control *rstc;
};

#define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL	0x24
#define OCELOT_IF_SI_OWNER_OFFSET		4
#define JAGUAR2_IF_SI_OWNER_OFFSET		6
#define MSCC_IF_SI_OWNER_MASK			GENMASK(1, 0)
#define MSCC_IF_SI_OWNER_SISL			0
#define MSCC_IF_SI_OWNER_SIBM			1
#define MSCC_IF_SI_OWNER_SIMC			2

#define MSCC_SPI_MST_SW_MODE			0x14
#define MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE	BIT(13)
#define MSCC_SPI_MST_SW_MODE_SW_SPI_CS(x)	(x << 5)

#define SPARX5_FORCE_ENA			0xa4
#define SPARX5_FORCE_VAL			0xa8

struct dw_spi_mscc {
	struct regmap       *syscon;
	void __iomem        *spi_mst; /* Not sparx5 */
};

/*
 * Elba SoC does not use ssi, pin override is used for cs 0,1 and
 * gpios for cs 2,3 as defined in the device tree.
 *
 * cs:  |       1               0
 * bit: |---3-------2-------1-------0
 *      |  cs1   cs1_ovr   cs0   cs0_ovr
 */
#define ELBA_SPICS_REG			0x2468
#define ELBA_SPICS_OFFSET(cs)		((cs) << 1)
#define ELBA_SPICS_MASK(cs)		(GENMASK(1, 0) << ELBA_SPICS_OFFSET(cs))
#define ELBA_SPICS_SET(cs, val)		\
		((((val) << 1) | BIT(0)) << ELBA_SPICS_OFFSET(cs))

/*
 * The Designware SPI controller (referred to as master in the documentation)
 * automatically deasserts chip select when the tx fifo is empty. The chip
 * selects then needs to be either driven as GPIOs or, for the first 4 using
 * the SPI boot controller registers. the final chip select is an OR gate
 * between the Designware SPI controller and the SPI boot controller.
 */
static void dw_spi_mscc_set_cs(struct spi_device *spi, bool enable)
{
	struct dw_spi *dws = spi_controller_get_devdata(spi->controller);
	struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
	struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
	u32 cs = spi_get_chipselect(spi, 0);

	if (cs < 4) {
		u32 sw_mode = MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE;

		if (!enable)
			sw_mode |= MSCC_SPI_MST_SW_MODE_SW_SPI_CS(BIT(cs));

		writel(sw_mode, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
	}

	dw_spi_set_cs(spi, enable);
}

static int dw_spi_mscc_init(struct platform_device *pdev,
			    struct dw_spi_mmio *dwsmmio,
			    const char *cpu_syscon, u32 if_si_owner_offset)
{
	struct dw_spi_mscc *dwsmscc;

	dwsmscc = devm_kzalloc(&pdev->dev, sizeof(*dwsmscc), GFP_KERNEL);
	if (!dwsmscc)
		return -ENOMEM;

	dwsmscc->spi_mst = devm_platform_ioremap_resource(pdev, 1);
	if (IS_ERR(dwsmscc->spi_mst)) {
		dev_err(&pdev->dev, "SPI_MST region map failed\n");
		return PTR_ERR(dwsmscc->spi_mst);
	}

	dwsmscc->syscon = syscon_regmap_lookup_by_compatible(cpu_syscon);
	if (IS_ERR(dwsmscc->syscon))
		return PTR_ERR(dwsmscc->syscon);

	/* Deassert all CS */
	writel(0, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);

	/* Select the owner of the SI interface */
	regmap_update_bits(dwsmscc->syscon, MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL,
			   MSCC_IF_SI_OWNER_MASK << if_si_owner_offset,
			   MSCC_IF_SI_OWNER_SIMC << if_si_owner_offset);

	dwsmmio->dws.set_cs = dw_spi_mscc_set_cs;
	dwsmmio->priv = dwsmscc;

	return 0;
}

static int dw_spi_mscc_ocelot_init(struct platform_device *pdev,
				   struct dw_spi_mmio *dwsmmio)
{
	return dw_spi_mscc_init(pdev, dwsmmio, "mscc,ocelot-cpu-syscon",
				OCELOT_IF_SI_OWNER_OFFSET);
}

static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev,
				    struct dw_spi_mmio *dwsmmio)
{
	return dw_spi_mscc_init(pdev, dwsmmio, "mscc,jaguar2-cpu-syscon",
				JAGUAR2_IF_SI_OWNER_OFFSET);
}

/*
 * The Designware SPI controller (referred to as master in the
 * documentation) automatically deasserts chip select when the tx fifo
 * is empty. The chip selects then needs to be driven by a CS override
 * register. enable is an active low signal.
 */
static void dw_spi_sparx5_set_cs(struct spi_device *spi, bool enable)
{
	struct dw_spi *dws = spi_controller_get_devdata(spi->controller);
	struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
	struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
	u8 cs = spi_get_chipselect(spi, 0);

	if (!enable) {
		/* CS override drive enable */
		regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 1);
		/* Now set CSx enabled */
		regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~BIT(cs));
		/* Allow settle */
		usleep_range(1, 5);
	} else {
		/* CS value */
		regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~0);
		/* Allow settle */
		usleep_range(1, 5);
		/* CS override drive disable */
		regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 0);
	}

	dw_spi_set_cs(spi, enable);
}

static int dw_spi_mscc_sparx5_init(struct platform_device *pdev,
				   struct dw_spi_mmio *dwsmmio)
{
	const char *syscon_name = "microchip,sparx5-cpu-syscon";
	struct device *dev = &pdev->dev;
	struct dw_spi_mscc *dwsmscc;

	if (!IS_ENABLED(CONFIG_SPI_MUX)) {
		dev_err(dev, "This driver needs CONFIG_SPI_MUX\n");
		return -EOPNOTSUPP;
	}

	dwsmscc = devm_kzalloc(dev, sizeof(*dwsmscc), GFP_KERNEL);
	if (!dwsmscc)
		return -ENOMEM;

	dwsmscc->syscon =
		syscon_regmap_lookup_by_compatible(syscon_name);
	if (IS_ERR(dwsmscc->syscon)) {
		dev_err(dev, "No syscon map %s\n", syscon_name);
		return PTR_ERR(dwsmscc->syscon);
	}

	dwsmmio->dws.set_cs = dw_spi_sparx5_set_cs;
	dwsmmio->priv = dwsmscc;

	return 0;
}

static int dw_spi_alpine_init(struct platform_device *pdev,
			      struct dw_spi_mmio *dwsmmio)
{
	dwsmmio->dws.caps = DW_SPI_CAP_CS_OVERRIDE;

	return 0;
}

static int dw_spi_pssi_init(struct platform_device *pdev,
			    struct dw_spi_mmio *dwsmmio)
{
	dw_spi_dma_setup_generic(&dwsmmio->dws);

	return 0;
}

static int dw_spi_hssi_init(struct platform_device *pdev,
			    struct dw_spi_mmio *dwsmmio)
{
	dwsmmio->dws.ip = DW_HSSI_ID;

	dw_spi_dma_setup_generic(&dwsmmio->dws);

	return 0;
}

static int dw_spi_intel_init(struct platform_device *pdev,
			     struct dw_spi_mmio *dwsmmio)
{
	dwsmmio->dws.ip = DW_HSSI_ID;

	return 0;
}

/*
 * DMA-based mem ops are not configured for this device and are not tested.
 */
static int dw_spi_mountevans_imc_init(struct platform_device *pdev,
				      struct dw_spi_mmio *dwsmmio)
{
	/*
	 * The Intel Mount Evans SoC's Integrated Management Complex DW
	 * apb_ssi_v4.02a controller has an errata where a full TX FIFO can
	 * result in data corruption. The suggested workaround is to never
	 * completely fill the FIFO. The TX FIFO has a size of 32 so the
	 * fifo_len is set to 31.
	 */
	dwsmmio->dws.fifo_len = 31;

	return 0;
}

static int dw_spi_canaan_k210_init(struct platform_device *pdev,
				   struct dw_spi_mmio *dwsmmio)
{
	/*
	 * The Canaan Kendryte K210 SoC DW apb_ssi v4 spi controller is
	 * documented to have a 32 word deep TX and RX FIFO, which
	 * spi_hw_init() detects. However, when the RX FIFO is filled up to
	 * 32 entries (RXFLR = 32), an RX FIFO overrun error occurs. Avoid this
	 * problem by force setting fifo_len to 31.
	 */
	dwsmmio->dws.fifo_len = 31;

	return 0;
}

static void dw_spi_elba_override_cs(struct regmap *syscon, int cs, int enable)
{
	regmap_update_bits(syscon, ELBA_SPICS_REG, ELBA_SPICS_MASK(cs),
			   ELBA_SPICS_SET(cs, enable));
}

static void dw_spi_elba_set_cs(struct spi_device *spi, bool enable)
{
	struct dw_spi *dws = spi_controller_get_devdata(spi->controller);
	struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
	struct regmap *syscon = dwsmmio->priv;
	u8 cs;

	cs = spi_get_chipselect(spi, 0);
	if (cs < 2)
		dw_spi_elba_override_cs(syscon, spi_get_chipselect(spi, 0), enable);

	/*
	 * The DW SPI controller needs a native CS bit selected to start
	 * the serial engine.
	 */
	spi_set_chipselect(spi, 0, 0);
	dw_spi_set_cs(spi, enable);
	spi_set_chipselect(spi, 0, cs);
}

static int dw_spi_elba_init(struct platform_device *pdev,
			    struct dw_spi_mmio *dwsmmio)
{
	struct regmap *syscon;

	syscon = syscon_regmap_lookup_by_phandle(dev_of_node(&pdev->dev),
						 "amd,pensando-elba-syscon");
	if (IS_ERR(syscon))
		return dev_err_probe(&pdev->dev, PTR_ERR(syscon),
				     "syscon regmap lookup failed\n");

	dwsmmio->priv = syscon;
	dwsmmio->dws.set_cs = dw_spi_elba_set_cs;

	return 0;
}

static int dw_spi_mmio_probe(struct platform_device *pdev)
{
	int (*init_func)(struct platform_device *pdev,
			 struct dw_spi_mmio *dwsmmio);
	struct dw_spi_mmio *dwsmmio;
	struct resource *mem;
	struct dw_spi *dws;
	int ret;
	int num_cs;

	dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio),
			GFP_KERNEL);
	if (!dwsmmio)
		return -ENOMEM;

	dws = &dwsmmio->dws;

	/* Get basic io resource and map it */
	dws->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
	if (IS_ERR(dws->regs))
		return PTR_ERR(dws->regs);

	dws->paddr = mem->start;

	dws->irq = platform_get_irq(pdev, 0);
	if (dws->irq < 0)
		return dws->irq; /* -ENXIO */

	dwsmmio->clk = devm_clk_get_enabled(&pdev->dev, NULL);
	if (IS_ERR(dwsmmio->clk))
		return PTR_ERR(dwsmmio->clk);

	/* Optional clock needed to access the registers */
	dwsmmio->pclk = devm_clk_get_optional_enabled(&pdev->dev, "pclk");
	if (IS_ERR(dwsmmio->pclk))
		return PTR_ERR(dwsmmio->pclk);

	/* find an optional reset controller */
	dwsmmio->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi");
	if (IS_ERR(dwsmmio->rstc))
		return PTR_ERR(dwsmmio->rstc);

	reset_control_deassert(dwsmmio->rstc);

	dws->bus_num = pdev->id;

	dws->max_freq = clk_get_rate(dwsmmio->clk);

	if (device_property_read_u32(&pdev->dev, "reg-io-width",
				     &dws->reg_io_width))
		dws->reg_io_width = 4;

	num_cs = 4;

	device_property_read_u32(&pdev->dev, "num-cs", &num_cs);

	dws->num_cs = num_cs;

	init_func = device_get_match_data(&pdev->dev);
	if (init_func) {
		ret = init_func(pdev, dwsmmio);
		if (ret)
			goto out_reset;
	}

	pm_runtime_enable(&pdev->dev);

	ret = dw_spi_add_host(&pdev->dev, dws);
	if (ret)
		goto out;

	platform_set_drvdata(pdev, dwsmmio);
	return 0;

out:
	pm_runtime_disable(&pdev->dev);
out_reset:
	reset_control_assert(dwsmmio->rstc);

	return ret;
}

static void dw_spi_mmio_remove(struct platform_device *pdev)
{
	struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);

	dw_spi_remove_host(&dwsmmio->dws);
	pm_runtime_disable(&pdev->dev);
	reset_control_assert(dwsmmio->rstc);
}

static const struct of_device_id dw_spi_mmio_of_match[] = {
	{ .compatible = "snps,dw-apb-ssi", .data = dw_spi_pssi_init},
	{ .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_ocelot_init},
	{ .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init},
	{ .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init},
	{ .compatible = "renesas,rzn1-spi", .data = dw_spi_pssi_init},
	{ .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_hssi_init},
	{ .compatible = "intel,keembay-ssi", .data = dw_spi_intel_init},
	{
		.compatible = "intel,mountevans-imc-ssi",
		.data = dw_spi_mountevans_imc_init,
	},
	{ .compatible = "microchip,sparx5-spi", dw_spi_mscc_sparx5_init},
	{ .compatible = "canaan,k210-spi", dw_spi_canaan_k210_init},
	{ .compatible = "amd,pensando-elba-spi", .data = dw_spi_elba_init},
	{ /* end of table */}
};
MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);

#ifdef CONFIG_ACPI
static const struct acpi_device_id dw_spi_mmio_acpi_match[] = {
	{"HISI0173", (kernel_ulong_t)dw_spi_pssi_init},
	{},
};
MODULE_DEVICE_TABLE(acpi, dw_spi_mmio_acpi_match);
#endif

static struct platform_driver dw_spi_mmio_driver = {
	.probe		= dw_spi_mmio_probe,
	.remove_new	= dw_spi_mmio_remove,
	.driver		= {
		.name	= DRIVER_NAME,
		.of_match_table = dw_spi_mmio_of_match,
		.acpi_match_table = ACPI_PTR(dw_spi_mmio_acpi_match),
	},
};
module_platform_driver(dw_spi_mmio_driver);

MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(SPI_DW_CORE);