summaryrefslogtreecommitdiff
path: root/drivers/platform/x86/barco-p50-gpio.c
blob: 8dd67233948584f02bc0c62610179fd710d4c89d (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
// SPDX-License-Identifier: GPL-2.0+

/*
 * Support for EC-connected GPIOs for identify
 * LED/button on Barco P50 board
 *
 * Copyright (C) 2021 Barco NV
 * Author: Santosh Kumar Yadav <santoshkumar.yadav@barco.com>
 */

#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio_keys.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/input.h>


#define DRIVER_NAME		"barco-p50-gpio"

/* GPIO lines */
#define P50_GPIO_LINE_LED	0
#define P50_GPIO_LINE_BTN	1

/* GPIO IO Ports */
#define P50_GPIO_IO_PORT_BASE	0x299

#define P50_PORT_DATA		0x00
#define P50_PORT_CMD		0x01

#define P50_STATUS_OBF		0x01 /* EC output buffer full */
#define P50_STATUS_IBF		0x02 /* EC input buffer full */

#define P50_CMD_READ		0xa0
#define P50_CMD_WRITE		0x50

/* EC mailbox registers */
#define P50_MBOX_REG_CMD	0x00
#define P50_MBOX_REG_STATUS	0x01
#define P50_MBOX_REG_PARAM	0x02
#define P50_MBOX_REG_DATA	0x03

#define P50_MBOX_CMD_READ_GPIO	0x11
#define P50_MBOX_CMD_WRITE_GPIO	0x12
#define P50_MBOX_CMD_CLEAR	0xff

#define P50_MBOX_STATUS_SUCCESS	0x01

#define P50_MBOX_PARAM_LED	0x12
#define P50_MBOX_PARAM_BTN	0x13


struct p50_gpio {
	struct gpio_chip gc;
	struct mutex lock;
	unsigned long base;
	struct platform_device *leds_pdev;
	struct platform_device *keys_pdev;
};

static struct platform_device *gpio_pdev;

static int gpio_params[] = {
	[P50_GPIO_LINE_LED] = P50_MBOX_PARAM_LED,
	[P50_GPIO_LINE_BTN] = P50_MBOX_PARAM_BTN,
};

static const char * const gpio_names[] = {
	[P50_GPIO_LINE_LED] = "identify-led",
	[P50_GPIO_LINE_BTN] = "identify-button",
};


static struct gpiod_lookup_table p50_gpio_led_table = {
	.dev_id = "leds-gpio",
	.table = {
		GPIO_LOOKUP_IDX(DRIVER_NAME, P50_GPIO_LINE_LED, NULL, 0, GPIO_ACTIVE_HIGH),
		{}
	}
};

/* GPIO LEDs */
static struct gpio_led leds[] = {
	{ .name = "identify" }
};

static struct gpio_led_platform_data leds_pdata = {
	.num_leds = ARRAY_SIZE(leds),
	.leds = leds,
};

/* GPIO keyboard */
static struct gpio_keys_button buttons[] = {
	{
		.code = KEY_VENDOR,
		.gpio = P50_GPIO_LINE_BTN,
		.active_low = 1,
		.type = EV_KEY,
		.value = 1,
	},
};

static struct gpio_keys_platform_data keys_pdata = {
	.buttons = buttons,
	.nbuttons = ARRAY_SIZE(buttons),
	.poll_interval = 100,
	.rep = 0,
	.name = "identify",
};


/* low level access routines */

static int p50_wait_ec(struct p50_gpio *p50, int mask, int expected)
{
	int i, val;

	for (i = 0; i < 100; i++) {
		val = inb(p50->base + P50_PORT_CMD) & mask;
		if (val == expected)
			return 0;
		usleep_range(500, 2000);
	}

	dev_err(p50->gc.parent, "Timed out waiting for EC (0x%x)\n", val);
	return -ETIMEDOUT;
}


static int p50_read_mbox_reg(struct p50_gpio *p50, int reg)
{
	int ret;

	ret = p50_wait_ec(p50, P50_STATUS_IBF, 0);
	if (ret)
		return ret;

	/* clear output buffer flag, prevent unfinished commands */
	inb(p50->base + P50_PORT_DATA);

	/* cmd/address */
	outb(P50_CMD_READ | reg, p50->base + P50_PORT_CMD);

	ret = p50_wait_ec(p50, P50_STATUS_OBF, P50_STATUS_OBF);
	if (ret)
		return ret;

	return inb(p50->base + P50_PORT_DATA);
}

static int p50_write_mbox_reg(struct p50_gpio *p50, int reg, int val)
{
	int ret;

	ret = p50_wait_ec(p50, P50_STATUS_IBF, 0);
	if (ret)
		return ret;

	/* cmd/address */
	outb(P50_CMD_WRITE | reg, p50->base + P50_PORT_CMD);

	ret = p50_wait_ec(p50, P50_STATUS_IBF, 0);
	if (ret)
		return ret;

	/* data */
	outb(val, p50->base + P50_PORT_DATA);

	return 0;
}


/* mbox routines */

static int p50_wait_mbox_idle(struct p50_gpio *p50)
{
	int i, val;

	for (i = 0; i < 1000; i++) {
		val = p50_read_mbox_reg(p50, P50_MBOX_REG_CMD);
		/* cmd is 0 when idle */
		if (val <= 0)
			return val;

		usleep_range(500, 2000);
	}

	dev_err(p50->gc.parent,	"Timed out waiting for EC mbox idle (CMD: 0x%x)\n", val);

	return -ETIMEDOUT;
}

static int p50_send_mbox_cmd(struct p50_gpio *p50, int cmd, int param, int data)
{
	int ret;

	ret = p50_wait_mbox_idle(p50);
	if (ret)
		return ret;

	ret = p50_write_mbox_reg(p50, P50_MBOX_REG_DATA, data);
	if (ret)
		return ret;

	ret = p50_write_mbox_reg(p50, P50_MBOX_REG_PARAM, param);
	if (ret)
		return ret;

	ret = p50_write_mbox_reg(p50, P50_MBOX_REG_CMD, cmd);
	if (ret)
		return ret;

	ret = p50_wait_mbox_idle(p50);
	if (ret)
		return ret;

	ret = p50_read_mbox_reg(p50, P50_MBOX_REG_STATUS);
	if (ret < 0)
		return ret;

	if (ret == P50_MBOX_STATUS_SUCCESS)
		return 0;

	dev_err(p50->gc.parent,	"Mbox command failed (CMD=0x%x STAT=0x%x PARAM=0x%x DATA=0x%x)\n",
		cmd, ret, param, data);

	return -EIO;
}


/* gpio routines */

static int p50_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
	switch (offset) {
	case P50_GPIO_LINE_BTN:
		return GPIO_LINE_DIRECTION_IN;

	case P50_GPIO_LINE_LED:
		return GPIO_LINE_DIRECTION_OUT;

	default:
		return -EINVAL;
	}
}

static int p50_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
	struct p50_gpio *p50 = gpiochip_get_data(gc);
	int ret;

	mutex_lock(&p50->lock);

	ret = p50_send_mbox_cmd(p50, P50_MBOX_CMD_READ_GPIO, gpio_params[offset], 0);
	if (ret == 0)
		ret = p50_read_mbox_reg(p50, P50_MBOX_REG_DATA);

	mutex_unlock(&p50->lock);

	return ret;
}

static void p50_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
{
	struct p50_gpio *p50 = gpiochip_get_data(gc);

	mutex_lock(&p50->lock);

	p50_send_mbox_cmd(p50, P50_MBOX_CMD_WRITE_GPIO, gpio_params[offset], value);

	mutex_unlock(&p50->lock);
}

static int p50_gpio_probe(struct platform_device *pdev)
{
	struct p50_gpio *p50;
	struct resource *res;
	int ret;

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (!res) {
		dev_err(&pdev->dev, "Cannot get I/O ports\n");
		return -ENODEV;
	}

	if (!devm_request_region(&pdev->dev, res->start, resource_size(res), pdev->name)) {
		dev_err(&pdev->dev, "Unable to reserve I/O region\n");
		return -EBUSY;
	}

	p50 = devm_kzalloc(&pdev->dev, sizeof(*p50), GFP_KERNEL);
	if (!p50)
		return -ENOMEM;

	platform_set_drvdata(pdev, p50);
	mutex_init(&p50->lock);
	p50->base = res->start;
	p50->gc.owner = THIS_MODULE;
	p50->gc.parent = &pdev->dev;
	p50->gc.label = dev_name(&pdev->dev);
	p50->gc.ngpio = ARRAY_SIZE(gpio_names);
	p50->gc.names = gpio_names;
	p50->gc.can_sleep = true;
	p50->gc.base = -1;
	p50->gc.get_direction = p50_gpio_get_direction;
	p50->gc.get = p50_gpio_get;
	p50->gc.set = p50_gpio_set;


	/* reset mbox */
	ret = p50_wait_mbox_idle(p50);
	if (ret)
		return ret;

	ret = p50_write_mbox_reg(p50, P50_MBOX_REG_CMD, P50_MBOX_CMD_CLEAR);
	if (ret)
		return ret;

	ret = p50_wait_mbox_idle(p50);
	if (ret)
		return ret;


	ret = devm_gpiochip_add_data(&pdev->dev, &p50->gc, p50);
	if (ret < 0) {
		dev_err(&pdev->dev, "Could not register gpiochip: %d\n", ret);
		return ret;
	}

	gpiod_add_lookup_table(&p50_gpio_led_table);

	p50->leds_pdev = platform_device_register_data(&pdev->dev,
		"leds-gpio", PLATFORM_DEVID_NONE, &leds_pdata, sizeof(leds_pdata));

	if (IS_ERR(p50->leds_pdev)) {
		ret = PTR_ERR(p50->leds_pdev);
		dev_err(&pdev->dev, "Could not register leds-gpio: %d\n", ret);
		goto err_leds;
	}

	/* gpio-keys-polled uses old-style gpio interface, pass the right identifier */
	buttons[0].gpio += p50->gc.base;

	p50->keys_pdev =
		platform_device_register_data(&pdev->dev, "gpio-keys-polled",
					      PLATFORM_DEVID_NONE,
					      &keys_pdata, sizeof(keys_pdata));

	if (IS_ERR(p50->keys_pdev)) {
		ret = PTR_ERR(p50->keys_pdev);
		dev_err(&pdev->dev, "Could not register gpio-keys-polled: %d\n", ret);
		goto err_keys;
	}

	return 0;

err_keys:
	platform_device_unregister(p50->leds_pdev);
err_leds:
	gpiod_remove_lookup_table(&p50_gpio_led_table);

	return ret;
}

static int p50_gpio_remove(struct platform_device *pdev)
{
	struct p50_gpio *p50 = platform_get_drvdata(pdev);

	platform_device_unregister(p50->keys_pdev);
	platform_device_unregister(p50->leds_pdev);

	gpiod_remove_lookup_table(&p50_gpio_led_table);

	return 0;
}

static struct platform_driver p50_gpio_driver = {
	.driver = {
		.name = DRIVER_NAME,
	},
	.probe = p50_gpio_probe,
	.remove = p50_gpio_remove,
};

/* Board setup */
static const struct dmi_system_id dmi_ids[] __initconst = {
	{
		.matches = {
			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Barco"),
			DMI_EXACT_MATCH(DMI_PRODUCT_FAMILY, "P50")
		},
	},
	{}
};
MODULE_DEVICE_TABLE(dmi, dmi_ids);

static int __init p50_module_init(void)
{
	struct resource res = DEFINE_RES_IO(P50_GPIO_IO_PORT_BASE, P50_PORT_CMD + 1);
	int ret;

	if (!dmi_first_match(dmi_ids))
		return -ENODEV;

	ret = platform_driver_register(&p50_gpio_driver);
	if (ret)
		return ret;

	gpio_pdev = platform_device_register_simple(DRIVER_NAME, PLATFORM_DEVID_NONE, &res, 1);
	if (IS_ERR(gpio_pdev)) {
		pr_err("failed registering %s: %ld\n", DRIVER_NAME, PTR_ERR(gpio_pdev));
		platform_driver_unregister(&p50_gpio_driver);
		return PTR_ERR(gpio_pdev);
	}

	return 0;
}

static void __exit p50_module_exit(void)
{
	platform_device_unregister(gpio_pdev);
	platform_driver_unregister(&p50_gpio_driver);
}

module_init(p50_module_init);
module_exit(p50_module_exit);

MODULE_AUTHOR("Santosh Kumar Yadav, Barco NV <santoshkumar.yadav@barco.com>");
MODULE_DESCRIPTION("Barco P50 identify GPIOs driver");
MODULE_LICENSE("GPL");