summaryrefslogtreecommitdiff
path: root/drivers/gpio/gpio-ljca.c
blob: 87863f0230f5cf051c2e9f2d7317a15970e5cc2a (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Intel La Jolla Cove Adapter USB-GPIO driver
 *
 * Copyright (c) 2023, Intel Corporation.
 */

#include <linux/acpi.h>
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/dev_printk.h>
#include <linux/gpio/driver.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/mfd/ljca.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>

/* GPIO commands */
#define LJCA_GPIO_CONFIG	1
#define LJCA_GPIO_READ		2
#define LJCA_GPIO_WRITE		3
#define LJCA_GPIO_INT_EVENT	4
#define LJCA_GPIO_INT_MASK	5
#define LJCA_GPIO_INT_UNMASK	6

#define LJCA_GPIO_CONF_DISABLE		BIT(0)
#define LJCA_GPIO_CONF_INPUT		BIT(1)
#define LJCA_GPIO_CONF_OUTPUT		BIT(2)
#define LJCA_GPIO_CONF_PULLUP		BIT(3)
#define LJCA_GPIO_CONF_PULLDOWN		BIT(4)
#define LJCA_GPIO_CONF_DEFAULT		BIT(5)
#define LJCA_GPIO_CONF_INTERRUPT	BIT(6)
#define LJCA_GPIO_INT_TYPE		BIT(7)

#define LJCA_GPIO_CONF_EDGE	FIELD_PREP(LJCA_GPIO_INT_TYPE, 1)
#define LJCA_GPIO_CONF_LEVEL	FIELD_PREP(LJCA_GPIO_INT_TYPE, 0)

/* Intentional overlap with PULLUP / PULLDOWN */
#define LJCA_GPIO_CONF_SET	BIT(3)
#define LJCA_GPIO_CONF_CLR	BIT(4)

struct gpio_op {
	u8 index;
	u8 value;
} __packed;

struct gpio_packet {
	u8 num;
	struct gpio_op item[];
} __packed;

#define LJCA_GPIO_BUF_SIZE 60
struct ljca_gpio_dev {
	struct platform_device *pdev;
	struct gpio_chip gc;
	struct ljca_gpio_info *gpio_info;
	DECLARE_BITMAP(unmasked_irqs, LJCA_MAX_GPIO_NUM);
	DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
	DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
	u8 *connect_mode;
	/* mutex to protect irq bus */
	struct mutex irq_lock;
	struct work_struct work;
	/* lock to protect package transfer to Hardware */
	struct mutex trans_lock;

	u8 obuf[LJCA_GPIO_BUF_SIZE];
	u8 ibuf[LJCA_GPIO_BUF_SIZE];
};

static int gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id, u8 config)
{
	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
	int ret;

	mutex_lock(&ljca_gpio->trans_lock);
	packet->item[0].index = gpio_id;
	packet->item[0].value = config | ljca_gpio->connect_mode[gpio_id];
	packet->num = 1;

	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_CONFIG, packet,
			    struct_size(packet, item, packet->num), NULL, NULL);
	mutex_unlock(&ljca_gpio->trans_lock);
	return ret;
}

static int ljca_gpio_read(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id)
{
	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
	struct gpio_packet *ack_packet = (struct gpio_packet *)ljca_gpio->ibuf;
	unsigned int ibuf_len = LJCA_GPIO_BUF_SIZE;
	int ret;

	mutex_lock(&ljca_gpio->trans_lock);
	packet->num = 1;
	packet->item[0].index = gpio_id;
	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_READ, packet,
			    struct_size(packet, item, packet->num), ljca_gpio->ibuf, &ibuf_len);
	if (ret)
		goto out_unlock;

	if (!ibuf_len || ack_packet->num != packet->num) {
		dev_err(&ljca_gpio->pdev->dev, "failed gpio_id:%u %u", gpio_id, ack_packet->num);
		ret = -EIO;
	}

out_unlock:
	mutex_unlock(&ljca_gpio->trans_lock);
	if (ret)
		return ret;
	return ack_packet->item[0].value > 0;
}

static int ljca_gpio_write(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
			   int value)
{
	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
	int ret;

	mutex_lock(&ljca_gpio->trans_lock);
	packet->num = 1;
	packet->item[0].index = gpio_id;
	packet->item[0].value = value & 1;

	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_WRITE, packet,
			    struct_size(packet, item, packet->num), NULL, NULL);
	mutex_unlock(&ljca_gpio->trans_lock);
	return ret;
}

static int ljca_gpio_get_value(struct gpio_chip *chip, unsigned int offset)
{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);

	return ljca_gpio_read(ljca_gpio, offset);
}

static void ljca_gpio_set_value(struct gpio_chip *chip, unsigned int offset,
				int val)
{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
	int ret;

	ret = ljca_gpio_write(ljca_gpio, offset, val);
	if (ret)
		dev_err(chip->parent, "offset:%u val:%d set value failed %d\n", offset, val, ret);
}

static int ljca_gpio_direction_input(struct gpio_chip *chip,
				     unsigned int offset)
{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
	u8 config = LJCA_GPIO_CONF_INPUT | LJCA_GPIO_CONF_CLR;

	return gpio_config(ljca_gpio, offset, config);
}

static int ljca_gpio_direction_output(struct gpio_chip *chip,
				      unsigned int offset, int val)
{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
	u8 config = LJCA_GPIO_CONF_OUTPUT | LJCA_GPIO_CONF_CLR;
	int ret;

	ret = gpio_config(ljca_gpio, offset, config);
	if (ret)
		return ret;

	ljca_gpio_set_value(chip, offset, val);
	return 0;
}

static int ljca_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
				unsigned long config)
{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);

	ljca_gpio->connect_mode[offset] = 0;
	switch (pinconf_to_config_param(config)) {
	case PIN_CONFIG_BIAS_PULL_UP:
		ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLUP;
		break;
	case PIN_CONFIG_BIAS_PULL_DOWN:
		ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLDOWN;
		break;
	case PIN_CONFIG_DRIVE_PUSH_PULL:
	case PIN_CONFIG_PERSIST_STATE:
		break;
	default:
		return -ENOTSUPP;
	}

	return 0;
}

static int ljca_gpio_init_valid_mask(struct gpio_chip *chip, unsigned long *valid_mask,
				     unsigned int ngpios)
{
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);

	WARN_ON_ONCE(ngpios != ljca_gpio->gpio_info->num);
	bitmap_copy(valid_mask, ljca_gpio->gpio_info->valid_pin_map, ngpios);

	return 0;
}

static void ljca_gpio_irq_init_valid_mask(struct gpio_chip *chip, unsigned long *valid_mask,
					  unsigned int ngpios)
{
	ljca_gpio_init_valid_mask(chip, valid_mask, ngpios);
}

static int ljca_enable_irq(struct ljca_gpio_dev *ljca_gpio, int gpio_id, bool enable)
{
	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
	int ret;

	mutex_lock(&ljca_gpio->trans_lock);
	packet->num = 1;
	packet->item[0].index = gpio_id;
	packet->item[0].value = 0;

	ret = ljca_transfer(ljca_gpio->gpio_info->ljca,
			    enable ? LJCA_GPIO_INT_UNMASK : LJCA_GPIO_INT_MASK, packet,
			    struct_size(packet, item, packet->num), NULL, NULL);
	mutex_unlock(&ljca_gpio->trans_lock);
	return ret;
}

static void ljca_gpio_async(struct work_struct *work)
{
	struct ljca_gpio_dev *ljca_gpio = container_of(work, struct ljca_gpio_dev, work);
	int gpio_id;
	int unmasked;

	for_each_set_bit(gpio_id, ljca_gpio->reenable_irqs, ljca_gpio->gc.ngpio) {
		clear_bit(gpio_id, ljca_gpio->reenable_irqs);
		unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
		if (unmasked)
			ljca_enable_irq(ljca_gpio, gpio_id, true);
	}
}

static void ljca_gpio_event_cb(void *context, u8 cmd, const void *evt_data, int len)
{
	const struct gpio_packet *packet = evt_data;
	struct ljca_gpio_dev *ljca_gpio = context;
	int i;
	int irq;

	if (cmd != LJCA_GPIO_INT_EVENT)
		return;

	for (i = 0; i < packet->num; i++) {
		irq = irq_find_mapping(ljca_gpio->gc.irq.domain, packet->item[i].index);
		if (!irq) {
			dev_err(ljca_gpio->gc.parent, "gpio_id %u does not mapped to IRQ yet\n",
				packet->item[i].index);
			return;
		}

		generic_handle_domain_irq(ljca_gpio->gc.irq.domain, irq);
		set_bit(packet->item[i].index, ljca_gpio->reenable_irqs);
	}

	schedule_work(&ljca_gpio->work);
}

static void ljca_irq_unmask(struct irq_data *irqd)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
	int gpio_id = irqd_to_hwirq(irqd);

	gpiochip_enable_irq(gc, gpio_id);
	set_bit(gpio_id, ljca_gpio->unmasked_irqs);
}

static void ljca_irq_mask(struct irq_data *irqd)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
	int gpio_id = irqd_to_hwirq(irqd);

	clear_bit(gpio_id, ljca_gpio->unmasked_irqs);
	gpiochip_disable_irq(gc, gpio_id);
}

static int ljca_irq_set_type(struct irq_data *irqd, unsigned int type)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
	int gpio_id = irqd_to_hwirq(irqd);

	ljca_gpio->connect_mode[gpio_id] = LJCA_GPIO_CONF_INTERRUPT;
	switch (type) {
	case IRQ_TYPE_LEVEL_HIGH:
		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLUP);
		break;
	case IRQ_TYPE_LEVEL_LOW:
		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLDOWN);
		break;
	case IRQ_TYPE_EDGE_BOTH:
		break;
	case IRQ_TYPE_EDGE_RISING:
		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLUP);
		break;
	case IRQ_TYPE_EDGE_FALLING:
		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLDOWN);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static void ljca_irq_bus_lock(struct irq_data *irqd)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);

	mutex_lock(&ljca_gpio->irq_lock);
}

static void ljca_irq_bus_unlock(struct irq_data *irqd)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
	int gpio_id = irqd_to_hwirq(irqd);
	int enabled;
	int unmasked;

	enabled = test_bit(gpio_id, ljca_gpio->enabled_irqs);
	unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);

	if (enabled != unmasked) {
		if (unmasked) {
			gpio_config(ljca_gpio, gpio_id, 0);
			ljca_enable_irq(ljca_gpio, gpio_id, true);
			set_bit(gpio_id, ljca_gpio->enabled_irqs);
		} else {
			ljca_enable_irq(ljca_gpio, gpio_id, false);
			clear_bit(gpio_id, ljca_gpio->enabled_irqs);
		}
	}

	mutex_unlock(&ljca_gpio->irq_lock);
}

static const struct irq_chip ljca_gpio_irqchip = {
	.name = "ljca-irq",
	.irq_mask = ljca_irq_mask,
	.irq_unmask = ljca_irq_unmask,
	.irq_set_type = ljca_irq_set_type,
	.irq_bus_lock = ljca_irq_bus_lock,
	.irq_bus_sync_unlock = ljca_irq_bus_unlock,
	.flags = IRQCHIP_IMMUTABLE,
	GPIOCHIP_IRQ_RESOURCE_HELPERS,
};

static int ljca_gpio_probe(struct platform_device *pdev)
{
	struct ljca_gpio_dev *ljca_gpio;
	struct gpio_irq_chip *girq;
	int ret;

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

	ljca_gpio->gpio_info = dev_get_platdata(&pdev->dev);
	ljca_gpio->connect_mode = devm_kcalloc(&pdev->dev, ljca_gpio->gpio_info->num,
					       sizeof(*ljca_gpio->connect_mode), GFP_KERNEL);
	if (!ljca_gpio->connect_mode)
		return -ENOMEM;

	mutex_init(&ljca_gpio->irq_lock);
	mutex_init(&ljca_gpio->trans_lock);
	ljca_gpio->pdev = pdev;
	ljca_gpio->gc.direction_input = ljca_gpio_direction_input;
	ljca_gpio->gc.direction_output = ljca_gpio_direction_output;
	ljca_gpio->gc.get = ljca_gpio_get_value;
	ljca_gpio->gc.set = ljca_gpio_set_value;
	ljca_gpio->gc.set_config = ljca_gpio_set_config;
	ljca_gpio->gc.init_valid_mask = ljca_gpio_init_valid_mask;
	ljca_gpio->gc.can_sleep = true;
	ljca_gpio->gc.parent = &pdev->dev;

	ljca_gpio->gc.base = -1;
	ljca_gpio->gc.ngpio = ljca_gpio->gpio_info->num;
	ljca_gpio->gc.label = ACPI_COMPANION(&pdev->dev) ?
			      acpi_dev_name(ACPI_COMPANION(&pdev->dev)) :
			      dev_name(&pdev->dev);
	ljca_gpio->gc.owner = THIS_MODULE;

	platform_set_drvdata(pdev, ljca_gpio);
	ljca_register_event_cb(ljca_gpio->gpio_info->ljca, ljca_gpio_event_cb, ljca_gpio);

	girq = &ljca_gpio->gc.irq;
	gpio_irq_chip_set_chip(girq, &ljca_gpio_irqchip);
	girq->parent_handler = NULL;
	girq->num_parents = 0;
	girq->parents = NULL;
	girq->default_type = IRQ_TYPE_NONE;
	girq->handler = handle_simple_irq;
	girq->init_valid_mask = ljca_gpio_irq_init_valid_mask;

	INIT_WORK(&ljca_gpio->work, ljca_gpio_async);
	ret = gpiochip_add_data(&ljca_gpio->gc, ljca_gpio);
	if (ret) {
		ljca_unregister_event_cb(ljca_gpio->gpio_info->ljca);
		mutex_destroy(&ljca_gpio->irq_lock);
		mutex_destroy(&ljca_gpio->trans_lock);
	}

	return ret;
}

static int ljca_gpio_remove(struct platform_device *pdev)
{
	struct ljca_gpio_dev *ljca_gpio = platform_get_drvdata(pdev);

	gpiochip_remove(&ljca_gpio->gc);
	ljca_unregister_event_cb(ljca_gpio->gpio_info->ljca);
	mutex_destroy(&ljca_gpio->irq_lock);
	mutex_destroy(&ljca_gpio->trans_lock);
	return 0;
}

#define LJCA_GPIO_DRV_NAME "ljca-gpio"
static const struct platform_device_id ljca_gpio_id[] = {
	{ LJCA_GPIO_DRV_NAME, 0 },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, ljca_gpio_id);

static struct platform_driver ljca_gpio_driver = {
	.driver.name = LJCA_GPIO_DRV_NAME,
	.probe = ljca_gpio_probe,
	.remove = ljca_gpio_remove,
};
module_platform_driver(ljca_gpio_driver);

MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
MODULE_AUTHOR("Wang Zhifeng <zhifeng.wang@intel.com>");
MODULE_AUTHOR("Zhang Lixu <lixu.zhang@intel.com>");
MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-GPIO driver");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(LJCA);