summaryrefslogtreecommitdiff
path: root/drivers/mfd/vexpress-sysreg.c
blob: 558c2928f2613f9011b00dafcbac5da71e0551d4 (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
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Copyright (C) 2012 ARM Limited
 */

#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/leds.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/timer.h>
#include <linux/vexpress.h>

#define SYS_ID			0x000
#define SYS_SW			0x004
#define SYS_LED			0x008
#define SYS_100HZ		0x024
#define SYS_FLAGS		0x030
#define SYS_FLAGSSET		0x030
#define SYS_FLAGSCLR		0x034
#define SYS_NVFLAGS		0x038
#define SYS_NVFLAGSSET		0x038
#define SYS_NVFLAGSCLR		0x03c
#define SYS_MCI			0x048
#define SYS_FLASH		0x04c
#define SYS_CFGSW		0x058
#define SYS_24MHZ		0x05c
#define SYS_MISC		0x060
#define SYS_DMA			0x064
#define SYS_PROCID0		0x084
#define SYS_PROCID1		0x088
#define SYS_CFGDATA		0x0a0
#define SYS_CFGCTRL		0x0a4
#define SYS_CFGSTAT		0x0a8

#define SYS_HBI_MASK		0xfff
#define SYS_ID_HBI_SHIFT	16
#define SYS_PROCIDx_HBI_SHIFT	0

#define SYS_MCI_CARDIN		(1 << 0)
#define SYS_MCI_WPROT		(1 << 1)

#define SYS_FLASH_WPn		(1 << 0)

#define SYS_MISC_MASTERSITE	(1 << 14)

#define SYS_CFGCTRL_START	(1 << 31)
#define SYS_CFGCTRL_WRITE	(1 << 30)
#define SYS_CFGCTRL_DCC(n)	(((n) & 0xf) << 26)
#define SYS_CFGCTRL_FUNC(n)	(((n) & 0x3f) << 20)
#define SYS_CFGCTRL_SITE(n)	(((n) & 0x3) << 16)
#define SYS_CFGCTRL_POSITION(n)	(((n) & 0xf) << 12)
#define SYS_CFGCTRL_DEVICE(n)	(((n) & 0xfff) << 0)

#define SYS_CFGSTAT_ERR		(1 << 1)
#define SYS_CFGSTAT_COMPLETE	(1 << 0)


static void __iomem *vexpress_sysreg_base;
static struct device *vexpress_sysreg_dev;
static int vexpress_master_site;


void vexpress_flags_set(u32 data)
{
	writel(~0, vexpress_sysreg_base + SYS_FLAGSCLR);
	writel(data, vexpress_sysreg_base + SYS_FLAGSSET);
}

u32 vexpress_get_procid(int site)
{
	if (site == VEXPRESS_SITE_MASTER)
		site = vexpress_master_site;

	return readl(vexpress_sysreg_base + (site == VEXPRESS_SITE_DB1 ?
			SYS_PROCID0 : SYS_PROCID1));
}

u32 vexpress_get_hbi(int site)
{
	u32 id;

	switch (site) {
	case VEXPRESS_SITE_MB:
		id = readl(vexpress_sysreg_base + SYS_ID);
		return (id >> SYS_ID_HBI_SHIFT) & SYS_HBI_MASK;
	case VEXPRESS_SITE_MASTER:
	case VEXPRESS_SITE_DB1:
	case VEXPRESS_SITE_DB2:
		id = vexpress_get_procid(site);
		return (id >> SYS_PROCIDx_HBI_SHIFT) & SYS_HBI_MASK;
	}

	return ~0;
}

void __iomem *vexpress_get_24mhz_clock_base(void)
{
	return vexpress_sysreg_base + SYS_24MHZ;
}


static void vexpress_sysreg_find_prop(struct device_node *node,
		const char *name, u32 *val)
{
	of_node_get(node);
	while (node) {
		if (of_property_read_u32(node, name, val) == 0) {
			of_node_put(node);
			return;
		}
		node = of_get_next_parent(node);
	}
}

unsigned __vexpress_get_site(struct device *dev, struct device_node *node)
{
	u32 site = 0;

	WARN_ON(dev && node && dev->of_node != node);
	if (dev && !node)
		node = dev->of_node;

	if (node) {
		vexpress_sysreg_find_prop(node, "arm,vexpress,site", &site);
	} else if (dev && dev->bus == &platform_bus_type) {
		struct platform_device *pdev = to_platform_device(dev);

		if (pdev->num_resources == 1 &&
				pdev->resource[0].flags == IORESOURCE_BUS)
			site = pdev->resource[0].start;
	} else if (dev && strncmp(dev_name(dev), "ct:", 3) == 0) {
		site = VEXPRESS_SITE_MASTER;
	}

	if (site == VEXPRESS_SITE_MASTER)
		site = vexpress_master_site;

	return site;
}


struct vexpress_sysreg_config_func {
	u32 template;
	u32 device;
};

static struct vexpress_config_bridge *vexpress_sysreg_config_bridge;
static struct timer_list vexpress_sysreg_config_timer;
static u32 *vexpress_sysreg_config_data;
static int vexpress_sysreg_config_tries;

static void *vexpress_sysreg_config_func_get(struct device *dev,
		struct device_node *node)
{
	struct vexpress_sysreg_config_func *config_func;
	u32 site;
	u32 position = 0;
	u32 dcc = 0;
	u32 func_device[2];
	int err = -EFAULT;

	if (node) {
		of_node_get(node);
		vexpress_sysreg_find_prop(node, "arm,vexpress,site", &site);
		vexpress_sysreg_find_prop(node, "arm,vexpress,position",
				&position);
		vexpress_sysreg_find_prop(node, "arm,vexpress,dcc", &dcc);
		err = of_property_read_u32_array(node,
				"arm,vexpress-sysreg,func", func_device,
				ARRAY_SIZE(func_device));
		of_node_put(node);
	} else if (dev && dev->bus == &platform_bus_type) {
		struct platform_device *pdev = to_platform_device(dev);

		if (pdev->num_resources == 1 &&
				pdev->resource[0].flags == IORESOURCE_BUS) {
			site = pdev->resource[0].start;
			func_device[0] = pdev->resource[0].end;
			func_device[1] = pdev->id;
			err = 0;
		}
	}
	if (err)
		return NULL;

	config_func = kzalloc(sizeof(*config_func), GFP_KERNEL);
	if (!config_func)
		return NULL;

	config_func->template = SYS_CFGCTRL_DCC(dcc);
	config_func->template |= SYS_CFGCTRL_FUNC(func_device[0]);
	config_func->template |= SYS_CFGCTRL_SITE(site == VEXPRESS_SITE_MASTER ?
			vexpress_master_site : site);
	config_func->template |= SYS_CFGCTRL_POSITION(position);
	config_func->device |= func_device[1];

	dev_dbg(vexpress_sysreg_dev, "func 0x%p = 0x%x, %d\n", config_func,
			config_func->template, config_func->device);

	return config_func;
}

static void vexpress_sysreg_config_func_put(void *func)
{
	kfree(func);
}

static int vexpress_sysreg_config_func_exec(void *func, int offset,
		bool write, u32 *data)
{
	int status;
	struct vexpress_sysreg_config_func *config_func = func;
	u32 command;

	if (WARN_ON(!vexpress_sysreg_base))
		return -ENOENT;

	command = readl(vexpress_sysreg_base + SYS_CFGCTRL);
	if (WARN_ON(command & SYS_CFGCTRL_START))
		return -EBUSY;

	command = SYS_CFGCTRL_START;
	command |= write ? SYS_CFGCTRL_WRITE : 0;
	command |= config_func->template;
	command |= SYS_CFGCTRL_DEVICE(config_func->device + offset);

	/* Use a canary for reads */
	if (!write)
		*data = 0xdeadbeef;

	dev_dbg(vexpress_sysreg_dev, "command %x, data %x\n",
			command, *data);
	writel(*data, vexpress_sysreg_base + SYS_CFGDATA);
	writel(0, vexpress_sysreg_base + SYS_CFGSTAT);
	writel(command, vexpress_sysreg_base + SYS_CFGCTRL);
	mb();

	if (vexpress_sysreg_dev) {
		/* Schedule completion check */
		if (!write)
			vexpress_sysreg_config_data = data;
		vexpress_sysreg_config_tries = 100;
		mod_timer(&vexpress_sysreg_config_timer,
				jiffies + usecs_to_jiffies(100));
		status = VEXPRESS_CONFIG_STATUS_WAIT;
	} else {
		/* Early execution, no timer available, have to spin */
		u32 cfgstat;

		do {
			cpu_relax();
			cfgstat = readl(vexpress_sysreg_base + SYS_CFGSTAT);
		} while (!cfgstat);

		if (!write && (cfgstat & SYS_CFGSTAT_COMPLETE))
			*data = readl(vexpress_sysreg_base + SYS_CFGDATA);
		status = VEXPRESS_CONFIG_STATUS_DONE;

		if (cfgstat & SYS_CFGSTAT_ERR)
			status = -EINVAL;
	}

	return status;
}

struct vexpress_config_bridge_info vexpress_sysreg_config_bridge_info = {
	.name = "vexpress-sysreg",
	.func_get = vexpress_sysreg_config_func_get,
	.func_put = vexpress_sysreg_config_func_put,
	.func_exec = vexpress_sysreg_config_func_exec,
};

static void vexpress_sysreg_config_complete(unsigned long data)
{
	int status = VEXPRESS_CONFIG_STATUS_DONE;
	u32 cfgstat = readl(vexpress_sysreg_base + SYS_CFGSTAT);

	if (cfgstat & SYS_CFGSTAT_ERR)
		status = -EINVAL;
	if (!vexpress_sysreg_config_tries--)
		status = -ETIMEDOUT;

	if (status < 0) {
		dev_err(vexpress_sysreg_dev, "error %d\n", status);
	} else if (!(cfgstat & SYS_CFGSTAT_COMPLETE)) {
		mod_timer(&vexpress_sysreg_config_timer,
				jiffies + usecs_to_jiffies(50));
		return;
	}

	if (vexpress_sysreg_config_data) {
		*vexpress_sysreg_config_data = readl(vexpress_sysreg_base +
				SYS_CFGDATA);
		dev_dbg(vexpress_sysreg_dev, "read data %x\n",
				*vexpress_sysreg_config_data);
		vexpress_sysreg_config_data = NULL;
	}

	vexpress_config_complete(vexpress_sysreg_config_bridge, status);
}


void vexpress_sysreg_setup(struct device_node *node)
{
	if (WARN_ON(!vexpress_sysreg_base))
		return;

	if (readl(vexpress_sysreg_base + SYS_MISC) & SYS_MISC_MASTERSITE)
		vexpress_master_site = VEXPRESS_SITE_DB2;
	else
		vexpress_master_site = VEXPRESS_SITE_DB1;

	vexpress_sysreg_config_bridge = vexpress_config_bridge_register(
			node, &vexpress_sysreg_config_bridge_info);
	WARN_ON(!vexpress_sysreg_config_bridge);
}

void __init vexpress_sysreg_early_init(void __iomem *base)
{
	vexpress_sysreg_base = base;
	vexpress_sysreg_setup(NULL);
}

void __init vexpress_sysreg_of_early_init(void)
{
	struct device_node *node = of_find_compatible_node(NULL, NULL,
			"arm,vexpress-sysreg");

	if (node) {
		vexpress_sysreg_base = of_iomap(node, 0);
		vexpress_sysreg_setup(node);
	} else {
		pr_info("vexpress-sysreg: No Device Tree node found.");
	}
}


static struct vexpress_sysreg_gpio {
	unsigned long reg;
	u32 value;
} vexpress_sysreg_gpios[] = {
	[VEXPRESS_GPIO_MMC_CARDIN] = {
		.reg = SYS_MCI,
		.value = SYS_MCI_CARDIN,
	},
	[VEXPRESS_GPIO_MMC_WPROT] = {
		.reg = SYS_MCI,
		.value = SYS_MCI_WPROT,
	},
	[VEXPRESS_GPIO_FLASH_WPn] = {
		.reg = SYS_FLASH,
		.value = SYS_FLASH_WPn,
	},
};

static int vexpress_sysreg_gpio_direction_input(struct gpio_chip *chip,
				       unsigned offset)
{
	return 0;
}

static int vexpress_sysreg_gpio_direction_output(struct gpio_chip *chip,
						unsigned offset, int value)
{
	return 0;
}

static int vexpress_sysreg_gpio_get(struct gpio_chip *chip,
				       unsigned offset)
{
	struct vexpress_sysreg_gpio *gpio = &vexpress_sysreg_gpios[offset];
	u32 reg_value = readl(vexpress_sysreg_base + gpio->reg);

	return !!(reg_value & gpio->value);
}

static void vexpress_sysreg_gpio_set(struct gpio_chip *chip,
				       unsigned offset, int value)
{
	struct vexpress_sysreg_gpio *gpio = &vexpress_sysreg_gpios[offset];
	u32 reg_value = readl(vexpress_sysreg_base + gpio->reg);

	if (value)
		reg_value |= gpio->value;
	else
		reg_value &= ~gpio->value;

	writel(reg_value, vexpress_sysreg_base + gpio->reg);
}

static struct gpio_chip vexpress_sysreg_gpio_chip = {
	.label = "vexpress-sysreg",
	.direction_input = vexpress_sysreg_gpio_direction_input,
	.direction_output = vexpress_sysreg_gpio_direction_output,
	.get = vexpress_sysreg_gpio_get,
	.set = vexpress_sysreg_gpio_set,
	.ngpio = ARRAY_SIZE(vexpress_sysreg_gpios),
	.base = 0,
};


static ssize_t vexpress_sysreg_sys_id_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "0x%08x\n", readl(vexpress_sysreg_base + SYS_ID));
}

DEVICE_ATTR(sys_id, S_IRUGO, vexpress_sysreg_sys_id_show, NULL);

static int vexpress_sysreg_probe(struct platform_device *pdev)
{
	int err;
	struct resource *res = platform_get_resource(pdev,
			IORESOURCE_MEM, 0);

	if (!devm_request_mem_region(&pdev->dev, res->start,
			resource_size(res), pdev->name)) {
		dev_err(&pdev->dev, "Failed to request memory region!\n");
		return -EBUSY;
	}

	if (!vexpress_sysreg_base) {
		vexpress_sysreg_base = devm_ioremap(&pdev->dev, res->start,
				resource_size(res));
		vexpress_sysreg_setup(pdev->dev.of_node);
	}

	if (!vexpress_sysreg_base) {
		dev_err(&pdev->dev, "Failed to obtain base address!\n");
		return -EFAULT;
	}

	setup_timer(&vexpress_sysreg_config_timer,
			vexpress_sysreg_config_complete, 0);

	vexpress_sysreg_gpio_chip.dev = &pdev->dev;
	err = gpiochip_add(&vexpress_sysreg_gpio_chip);
	if (err) {
		vexpress_config_bridge_unregister(
				vexpress_sysreg_config_bridge);
		dev_err(&pdev->dev, "Failed to register GPIO chip! (%d)\n",
				err);
		return err;
	}

	vexpress_sysreg_dev = &pdev->dev;

	device_create_file(vexpress_sysreg_dev, &dev_attr_sys_id);

	return 0;
}

static const struct of_device_id vexpress_sysreg_match[] = {
	{ .compatible = "arm,vexpress-sysreg", },
	{},
};

static struct platform_driver vexpress_sysreg_driver = {
	.driver = {
		.name = "vexpress-sysreg",
		.of_match_table = vexpress_sysreg_match,
	},
	.probe = vexpress_sysreg_probe,
};

static int __init vexpress_sysreg_init(void)
{
	return platform_driver_register(&vexpress_sysreg_driver);
}
core_initcall(vexpress_sysreg_init);