Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 277f48f1cc1c808f7356d7d8005ece67f8746cbc (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
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Intel Sunrisepoint LPSS core support.
 *
 * Copyright (C) 2015, Intel Corporation
 *
 * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
 *          Mika Westerberg <mika.westerberg@linux.intel.com>
 *          Heikki Krogerus <heikki.krogerus@linux.intel.com>
 *          Jarkko Nikula <jarkko.nikula@linux.intel.com>
 */

#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/debugfs.h>
#include <linux/idr.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mfd/core.h>
#include <linux/pm_qos.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
#include <linux/seq_file.h>
#include <linux/io-64-nonatomic-lo-hi.h>

#include <linux/dma/idma64.h>

#include "intel-lpss.h"

#define LPSS_DEV_OFFSET		0x000
#define LPSS_DEV_SIZE		0x200
#define LPSS_PRIV_OFFSET	0x200
#define LPSS_PRIV_SIZE		0x100
#define LPSS_PRIV_REG_COUNT	(LPSS_PRIV_SIZE / 4)
#define LPSS_IDMA64_OFFSET	0x800
#define LPSS_IDMA64_SIZE	0x800

/* Offsets from lpss->priv */
#define LPSS_PRIV_RESETS		0x04
#define LPSS_PRIV_RESETS_IDMA		BIT(2)
#define LPSS_PRIV_RESETS_FUNC		0x3

#define LPSS_PRIV_ACTIVELTR		0x10
#define LPSS_PRIV_IDLELTR		0x14

#define LPSS_PRIV_LTR_REQ		BIT(15)
#define LPSS_PRIV_LTR_SCALE_MASK	0xc00
#define LPSS_PRIV_LTR_SCALE_1US		0x800
#define LPSS_PRIV_LTR_SCALE_32US	0xc00
#define LPSS_PRIV_LTR_VALUE_MASK	0x3ff

#define LPSS_PRIV_SSP_REG		0x20
#define LPSS_PRIV_SSP_REG_DIS_DMA_FIN	BIT(0)

#define LPSS_PRIV_REMAP_ADDR		0x40

#define LPSS_PRIV_CAPS			0xfc
#define LPSS_PRIV_CAPS_NO_IDMA		BIT(8)
#define LPSS_PRIV_CAPS_TYPE_SHIFT	4
#define LPSS_PRIV_CAPS_TYPE_MASK	(0xf << LPSS_PRIV_CAPS_TYPE_SHIFT)

/* This matches the type field in CAPS register */
enum intel_lpss_dev_type {
	LPSS_DEV_I2C = 0,
	LPSS_DEV_UART,
	LPSS_DEV_SPI,
};

struct intel_lpss {
	const struct intel_lpss_platform_info *info;
	enum intel_lpss_dev_type type;
	struct clk *clk;
	struct clk_lookup *clock;
	struct mfd_cell *cell;
	struct device *dev;
	void __iomem *priv;
	u32 priv_ctx[LPSS_PRIV_REG_COUNT];
	int devid;
	u32 caps;
	u32 active_ltr;
	u32 idle_ltr;
	struct dentry *debugfs;
};

static const struct resource intel_lpss_dev_resources[] = {
	DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"),
	DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"),
	DEFINE_RES_IRQ(0),
};

static const struct resource intel_lpss_idma64_resources[] = {
	DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE),
	DEFINE_RES_IRQ(0),
};

/*
 * Cells needs to be ordered so that the iDMA is created first. This is
 * because we need to be sure the DMA is available when the host controller
 * driver is probed.
 */
static const struct mfd_cell intel_lpss_idma64_cell = {
	.name = LPSS_IDMA64_DRIVER_NAME,
	.num_resources = ARRAY_SIZE(intel_lpss_idma64_resources),
	.resources = intel_lpss_idma64_resources,
};

static const struct mfd_cell intel_lpss_i2c_cell = {
	.name = "i2c_designware",
	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
	.resources = intel_lpss_dev_resources,
};

static const struct mfd_cell intel_lpss_uart_cell = {
	.name = "dw-apb-uart",
	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
	.resources = intel_lpss_dev_resources,
};

static const struct mfd_cell intel_lpss_spi_cell = {
	.name = "pxa2xx-spi",
	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
	.resources = intel_lpss_dev_resources,
};

static DEFINE_IDA(intel_lpss_devid_ida);
static struct dentry *intel_lpss_debugfs;

static int intel_lpss_request_dma_module(const char *name)
{
	static bool intel_lpss_dma_requested;

	if (intel_lpss_dma_requested)
		return 0;

	intel_lpss_dma_requested = true;
	return request_module("%s", name);
}

static void intel_lpss_cache_ltr(struct intel_lpss *lpss)
{
	lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
	lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR);
}

static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
{
	struct dentry *dir;

	dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs);
	if (IS_ERR(dir))
		return PTR_ERR(dir);

	/* Cache the values into lpss structure */
	intel_lpss_cache_ltr(lpss);

	debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps);
	debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr);
	debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr);

	lpss->debugfs = dir;
	return 0;
}

static void intel_lpss_debugfs_remove(struct intel_lpss *lpss)
{
	debugfs_remove_recursive(lpss->debugfs);
}

static void intel_lpss_ltr_set(struct device *dev, s32 val)
{
	struct intel_lpss *lpss = dev_get_drvdata(dev);
	u32 ltr;

	/*
	 * Program latency tolerance (LTR) accordingly what has been asked
	 * by the PM QoS layer or disable it in case we were passed
	 * negative value or PM_QOS_LATENCY_ANY.
	 */
	ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);

	if (val == PM_QOS_LATENCY_ANY || val < 0) {
		ltr &= ~LPSS_PRIV_LTR_REQ;
	} else {
		ltr |= LPSS_PRIV_LTR_REQ;
		ltr &= ~LPSS_PRIV_LTR_SCALE_MASK;
		ltr &= ~LPSS_PRIV_LTR_VALUE_MASK;

		if (val > LPSS_PRIV_LTR_VALUE_MASK)
			ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5;
		else
			ltr |= LPSS_PRIV_LTR_SCALE_1US | val;
	}

	if (ltr == lpss->active_ltr)
		return;

	writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR);
	writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR);

	/* Cache the values into lpss structure */
	intel_lpss_cache_ltr(lpss);
}

static void intel_lpss_ltr_expose(struct intel_lpss *lpss)
{
	lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set;
	dev_pm_qos_expose_latency_tolerance(lpss->dev);
}

static void intel_lpss_ltr_hide(struct intel_lpss *lpss)
{
	dev_pm_qos_hide_latency_tolerance(lpss->dev);
	lpss->dev->power.set_latency_tolerance = NULL;
}

static int intel_lpss_assign_devs(struct intel_lpss *lpss)
{
	const struct mfd_cell *cell;
	unsigned int type;

	type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
	type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;

	switch (type) {
	case LPSS_DEV_I2C:
		cell = &intel_lpss_i2c_cell;
		break;
	case LPSS_DEV_UART:
		cell = &intel_lpss_uart_cell;
		break;
	case LPSS_DEV_SPI:
		cell = &intel_lpss_spi_cell;
		break;
	default:
		return -ENODEV;
	}

	lpss->cell = devm_kmemdup(lpss->dev, cell, sizeof(*cell), GFP_KERNEL);
	if (!lpss->cell)
		return -ENOMEM;

	lpss->type = type;

	return 0;
}

static bool intel_lpss_has_idma(const struct intel_lpss *lpss)
{
	return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0;
}

static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss)
{
	resource_size_t addr = lpss->info->mem->start;

	lo_hi_writeq(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR);
}

static void intel_lpss_deassert_reset(const struct intel_lpss *lpss)
{
	u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA;

	/* Bring out the device from reset */
	writel(value, lpss->priv + LPSS_PRIV_RESETS);
}

static void intel_lpss_init_dev(const struct intel_lpss *lpss)
{
	u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;

	/* Set the device in reset state */
	writel(0, lpss->priv + LPSS_PRIV_RESETS);

	intel_lpss_deassert_reset(lpss);

	intel_lpss_set_remap_addr(lpss);

	if (!intel_lpss_has_idma(lpss))
		return;

	/* Make sure that SPI multiblock DMA transfers are re-enabled */
	if (lpss->type == LPSS_DEV_SPI)
		writel(value, lpss->priv + LPSS_PRIV_SSP_REG);
}

static void intel_lpss_unregister_clock_tree(struct clk *clk)
{
	struct clk *parent;

	while (clk) {
		parent = clk_get_parent(clk);
		clk_unregister(clk);
		clk = parent;
	}
}

static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
					     const char *devname,
					     struct clk **clk)
{
	char name[32];
	struct clk *tmp = *clk;

	snprintf(name, sizeof(name), "%s-enable", devname);
	tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
				lpss->priv, 0, 0, NULL);
	if (IS_ERR(tmp))
		return PTR_ERR(tmp);

	snprintf(name, sizeof(name), "%s-div", devname);
	tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp),
					      0, lpss->priv, 1, 15, 16, 15, 0,
					      NULL);
	if (IS_ERR(tmp))
		return PTR_ERR(tmp);
	*clk = tmp;

	snprintf(name, sizeof(name), "%s-update", devname);
	tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
				CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);
	if (IS_ERR(tmp))
		return PTR_ERR(tmp);
	*clk = tmp;

	return 0;
}

static int intel_lpss_register_clock(struct intel_lpss *lpss)
{
	const struct mfd_cell *cell = lpss->cell;
	struct clk *clk;
	char devname[24];
	int ret;

	if (!lpss->info->clk_rate)
		return 0;

	/* Root clock */
	clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL, 0,
				      lpss->info->clk_rate);
	if (IS_ERR(clk))
		return PTR_ERR(clk);

	snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid);

	/*
	 * Support for clock divider only if it has some preset value.
	 * Otherwise we assume that the divider is not used.
	 */
	if (lpss->type != LPSS_DEV_I2C) {
		ret = intel_lpss_register_clock_divider(lpss, devname, &clk);
		if (ret)
			goto err_clk_register;
	}

	ret = -ENOMEM;

	/* Clock for the host controller */
	lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname);
	if (!lpss->clock)
		goto err_clk_register;

	lpss->clk = clk;

	return 0;

err_clk_register:
	intel_lpss_unregister_clock_tree(clk);

	return ret;
}

static void intel_lpss_unregister_clock(struct intel_lpss *lpss)
{
	if (IS_ERR_OR_NULL(lpss->clk))
		return;

	clkdev_drop(lpss->clock);
	intel_lpss_unregister_clock_tree(lpss->clk);
}

int intel_lpss_probe(struct device *dev,
		     const struct intel_lpss_platform_info *info)
{
	struct intel_lpss *lpss;
	int ret;

	if (!info || !info->mem || info->irq <= 0)
		return -EINVAL;

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

	lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET,
				  LPSS_PRIV_SIZE);
	if (!lpss->priv)
		return -ENOMEM;

	lpss->info = info;
	lpss->dev = dev;
	lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS);

	dev_set_drvdata(dev, lpss);

	ret = intel_lpss_assign_devs(lpss);
	if (ret)
		return ret;

	lpss->cell->properties = info->properties;

	intel_lpss_init_dev(lpss);

	lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL);
	if (lpss->devid < 0)
		return lpss->devid;

	ret = intel_lpss_register_clock(lpss);
	if (ret)
		goto err_clk_register;

	intel_lpss_ltr_expose(lpss);

	ret = intel_lpss_debugfs_add(lpss);
	if (ret)
		dev_warn(dev, "Failed to create debugfs entries\n");

	if (intel_lpss_has_idma(lpss)) {
		/*
		 * Ensure the DMA driver is loaded before the host
		 * controller device appears, so that the host controller
		 * driver can request its DMA channels as early as
		 * possible.
		 *
		 * If the DMA module is not there that's OK as well.
		 */
		intel_lpss_request_dma_module(LPSS_IDMA64_DRIVER_NAME);

		ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell,
				      1, info->mem, info->irq, NULL);
		if (ret)
			dev_warn(dev, "Failed to add %s, fallback to PIO\n",
				 LPSS_IDMA64_DRIVER_NAME);
	}

	ret = mfd_add_devices(dev, lpss->devid, lpss->cell,
			      1, info->mem, info->irq, NULL);
	if (ret)
		goto err_remove_ltr;

	dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND);

	return 0;

err_remove_ltr:
	intel_lpss_debugfs_remove(lpss);
	intel_lpss_ltr_hide(lpss);
	intel_lpss_unregister_clock(lpss);

err_clk_register:
	ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);

	return ret;
}
EXPORT_SYMBOL_GPL(intel_lpss_probe);

void intel_lpss_remove(struct device *dev)
{
	struct intel_lpss *lpss = dev_get_drvdata(dev);

	mfd_remove_devices(dev);
	intel_lpss_debugfs_remove(lpss);
	intel_lpss_ltr_hide(lpss);
	intel_lpss_unregister_clock(lpss);
	ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
}
EXPORT_SYMBOL_GPL(intel_lpss_remove);

static int resume_lpss_device(struct device *dev, void *data)
{
	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND))
		pm_runtime_resume(dev);

	return 0;
}

int intel_lpss_prepare(struct device *dev)
{
	/*
	 * Resume both child devices before entering system sleep. This
	 * ensures that they are in proper state before they get suspended.
	 */
	device_for_each_child_reverse(dev, NULL, resume_lpss_device);
	return 0;
}
EXPORT_SYMBOL_GPL(intel_lpss_prepare);

int intel_lpss_suspend(struct device *dev)
{
	struct intel_lpss *lpss = dev_get_drvdata(dev);
	unsigned int i;

	/* Save device context */
	for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
		lpss->priv_ctx[i] = readl(lpss->priv + i * 4);

	/*
	 * If the device type is not UART, then put the controller into
	 * reset. UART cannot be put into reset since S3/S0ix fail when
	 * no_console_suspend flag is enabled.
	 */
	if (lpss->type != LPSS_DEV_UART)
		writel(0, lpss->priv + LPSS_PRIV_RESETS);

	return 0;
}
EXPORT_SYMBOL_GPL(intel_lpss_suspend);

int intel_lpss_resume(struct device *dev)
{
	struct intel_lpss *lpss = dev_get_drvdata(dev);
	unsigned int i;

	intel_lpss_deassert_reset(lpss);

	/* Restore device context */
	for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
		writel(lpss->priv_ctx[i], lpss->priv + i * 4);

	return 0;
}
EXPORT_SYMBOL_GPL(intel_lpss_resume);

static int __init intel_lpss_init(void)
{
	intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
	return 0;
}
module_init(intel_lpss_init);

static void __exit intel_lpss_exit(void)
{
	ida_destroy(&intel_lpss_devid_ida);
	debugfs_remove(intel_lpss_debugfs);
}
module_exit(intel_lpss_exit);

MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
MODULE_DESCRIPTION("Intel LPSS core driver");
MODULE_LICENSE("GPL v2");