summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-em.c
blob: a87951293aaac50f72dc9ea2cbb86e2851a79847 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Emma Mobile GPIO Support - GIO
 *
 *  Copyright (C) 2012 Magnus Damm
 */

#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/pinctrl/consumer.h>

struct em_gio_priv {
	void __iomem *base0;
	void __iomem *base1;
	spinlock_t sense_lock;
	struct platform_device *pdev;
	struct gpio_chip gpio_chip;
	struct irq_chip irq_chip;
	struct irq_domain *irq_domain;
};

#define GIO_E1 0x00
#define GIO_E0 0x04
#define GIO_EM 0x04
#define GIO_OL 0x08
#define GIO_OH 0x0c
#define GIO_I 0x10
#define GIO_IIA 0x14
#define GIO_IEN 0x18
#define GIO_IDS 0x1c
#define GIO_IIM 0x1c
#define GIO_RAW 0x20
#define GIO_MST 0x24
#define GIO_IIR 0x28

#define GIO_IDT0 0x40
#define GIO_IDT1 0x44
#define GIO_IDT2 0x48
#define GIO_IDT3 0x4c
#define GIO_RAWBL 0x50
#define GIO_RAWBH 0x54
#define GIO_IRBL 0x58
#define GIO_IRBH 0x5c

#define GIO_IDT(n) (GIO_IDT0 + ((n) * 4))

static inline unsigned long em_gio_read(struct em_gio_priv *p, int offs)
{
	if (offs < GIO_IDT0)
		return ioread32(p->base0 + offs);
	else
		return ioread32(p->base1 + (offs - GIO_IDT0));
}

static inline void em_gio_write(struct em_gio_priv *p, int offs,
				unsigned long value)
{
	if (offs < GIO_IDT0)
		iowrite32(value, p->base0 + offs);
	else
		iowrite32(value, p->base1 + (offs - GIO_IDT0));
}

static void em_gio_irq_disable(struct irq_data *d)
{
	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);

	em_gio_write(p, GIO_IDS, BIT(irqd_to_hwirq(d)));
}

static void em_gio_irq_enable(struct irq_data *d)
{
	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);

	em_gio_write(p, GIO_IEN, BIT(irqd_to_hwirq(d)));
}

static int em_gio_irq_reqres(struct irq_data *d)
{
	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
	int ret;

	ret = gpiochip_lock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
	if (ret) {
		dev_err(p->gpio_chip.parent,
			"unable to lock HW IRQ %lu for IRQ\n",
			irqd_to_hwirq(d));
		return ret;
	}
	return 0;
}

static void em_gio_irq_relres(struct irq_data *d)
{
	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);

	gpiochip_unlock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
}


#define GIO_ASYNC(x) (x + 8)

static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
	[IRQ_TYPE_EDGE_RISING] = GIO_ASYNC(0x00),
	[IRQ_TYPE_EDGE_FALLING] = GIO_ASYNC(0x01),
	[IRQ_TYPE_LEVEL_HIGH] = GIO_ASYNC(0x02),
	[IRQ_TYPE_LEVEL_LOW] = GIO_ASYNC(0x03),
	[IRQ_TYPE_EDGE_BOTH] = GIO_ASYNC(0x04),
};

static int em_gio_irq_set_type(struct irq_data *d, unsigned int type)
{
	unsigned char value = em_gio_sense_table[type & IRQ_TYPE_SENSE_MASK];
	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
	unsigned int reg, offset, shift;
	unsigned long flags;
	unsigned long tmp;

	if (!value)
		return -EINVAL;

	offset = irqd_to_hwirq(d);

	pr_debug("gio: sense irq = %d, mode = %d\n", offset, value);

	/* 8 x 4 bit fields in 4 IDT registers */
	reg = GIO_IDT(offset >> 3);
	shift = (offset & 0x07) << 4;

	spin_lock_irqsave(&p->sense_lock, flags);

	/* disable the interrupt in IIA */
	tmp = em_gio_read(p, GIO_IIA);
	tmp &= ~BIT(offset);
	em_gio_write(p, GIO_IIA, tmp);

	/* change the sense setting in IDT */
	tmp = em_gio_read(p, reg);
	tmp &= ~(0xf << shift);
	tmp |= value << shift;
	em_gio_write(p, reg, tmp);

	/* clear pending interrupts */
	em_gio_write(p, GIO_IIR, BIT(offset));

	/* enable the interrupt in IIA */
	tmp = em_gio_read(p, GIO_IIA);
	tmp |= BIT(offset);
	em_gio_write(p, GIO_IIA, tmp);

	spin_unlock_irqrestore(&p->sense_lock, flags);

	return 0;
}

static irqreturn_t em_gio_irq_handler(int irq, void *dev_id)
{
	struct em_gio_priv *p = dev_id;
	unsigned long pending;
	unsigned int offset, irqs_handled = 0;

	while ((pending = em_gio_read(p, GIO_MST))) {
		offset = __ffs(pending);
		em_gio_write(p, GIO_IIR, BIT(offset));
		generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
		irqs_handled++;
	}

	return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
}

static inline struct em_gio_priv *gpio_to_priv(struct gpio_chip *chip)
{
	return gpiochip_get_data(chip);
}

static int em_gio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	em_gio_write(gpio_to_priv(chip), GIO_E0, BIT(offset));
	return 0;
}

static int em_gio_get(struct gpio_chip *chip, unsigned offset)
{
	return !!(em_gio_read(gpio_to_priv(chip), GIO_I) & BIT(offset));
}

static void __em_gio_set(struct gpio_chip *chip, unsigned int reg,
			 unsigned shift, int value)
{
	/* upper 16 bits contains mask and lower 16 actual value */
	em_gio_write(gpio_to_priv(chip), reg,
		     (BIT(shift + 16)) | (value << shift));
}

static void em_gio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	/* output is split into two registers */
	if (offset < 16)
		__em_gio_set(chip, GIO_OL, offset, value);
	else
		__em_gio_set(chip, GIO_OH, offset - 16, value);
}

static int em_gio_direction_output(struct gpio_chip *chip, unsigned offset,
				   int value)
{
	/* write GPIO value to output before selecting output mode of pin */
	em_gio_set(chip, offset, value);
	em_gio_write(gpio_to_priv(chip), GIO_E1, BIT(offset));
	return 0;
}

static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset)
{
	return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
}

static int em_gio_request(struct gpio_chip *chip, unsigned offset)
{
	return pinctrl_gpio_request(chip->base + offset);
}

static void em_gio_free(struct gpio_chip *chip, unsigned offset)
{
	pinctrl_gpio_free(chip->base + offset);

	/* Set the GPIO as an input to ensure that the next GPIO request won't
	* drive the GPIO pin as an output.
	*/
	em_gio_direction_input(chip, offset);
}

static int em_gio_irq_domain_map(struct irq_domain *h, unsigned int irq,
				 irq_hw_number_t hwirq)
{
	struct em_gio_priv *p = h->host_data;

	pr_debug("gio: map hw irq = %d, irq = %d\n", (int)hwirq, irq);

	irq_set_chip_data(irq, h->host_data);
	irq_set_chip_and_handler(irq, &p->irq_chip, handle_level_irq);
	return 0;
}

static const struct irq_domain_ops em_gio_irq_domain_ops = {
	.map	= em_gio_irq_domain_map,
	.xlate	= irq_domain_xlate_twocell,
};

static void em_gio_irq_domain_remove(void *data)
{
	struct irq_domain *domain = data;

	irq_domain_remove(domain);
}

static int em_gio_probe(struct platform_device *pdev)
{
	struct em_gio_priv *p;
	struct resource *io[2], *irq[2];
	struct gpio_chip *gpio_chip;
	struct irq_chip *irq_chip;
	const char *name = dev_name(&pdev->dev);
	unsigned int ngpios;
	int ret;

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

	p->pdev = pdev;
	platform_set_drvdata(pdev, p);
	spin_lock_init(&p->sense_lock);

	io[0] = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	io[1] = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);

	if (!io[0] || !io[1] || !irq[0] || !irq[1]) {
		dev_err(&pdev->dev, "missing IRQ or IOMEM\n");
		return -EINVAL;
	}

	p->base0 = devm_ioremap_nocache(&pdev->dev, io[0]->start,
					resource_size(io[0]));
	if (!p->base0)
		return -ENOMEM;

	p->base1 = devm_ioremap_nocache(&pdev->dev, io[1]->start,
				   resource_size(io[1]));
	if (!p->base1)
		return -ENOMEM;

	if (of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios)) {
		dev_err(&pdev->dev, "Missing ngpios OF property\n");
		return -EINVAL;
	}

	gpio_chip = &p->gpio_chip;
	gpio_chip->of_node = pdev->dev.of_node;
	gpio_chip->direction_input = em_gio_direction_input;
	gpio_chip->get = em_gio_get;
	gpio_chip->direction_output = em_gio_direction_output;
	gpio_chip->set = em_gio_set;
	gpio_chip->to_irq = em_gio_to_irq;
	gpio_chip->request = em_gio_request;
	gpio_chip->free = em_gio_free;
	gpio_chip->label = name;
	gpio_chip->parent = &pdev->dev;
	gpio_chip->owner = THIS_MODULE;
	gpio_chip->base = -1;
	gpio_chip->ngpio = ngpios;

	irq_chip = &p->irq_chip;
	irq_chip->name = name;
	irq_chip->irq_mask = em_gio_irq_disable;
	irq_chip->irq_unmask = em_gio_irq_enable;
	irq_chip->irq_set_type = em_gio_irq_set_type;
	irq_chip->irq_request_resources = em_gio_irq_reqres;
	irq_chip->irq_release_resources = em_gio_irq_relres;
	irq_chip->flags	= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND;

	p->irq_domain = irq_domain_add_simple(pdev->dev.of_node, ngpios, 0,
					      &em_gio_irq_domain_ops, p);
	if (!p->irq_domain) {
		dev_err(&pdev->dev, "cannot initialize irq domain\n");
		return -ENXIO;
	}

	ret = devm_add_action_or_reset(&pdev->dev, em_gio_irq_domain_remove,
				       p->irq_domain);
	if (ret)
		return ret;

	if (devm_request_irq(&pdev->dev, irq[0]->start,
			     em_gio_irq_handler, 0, name, p)) {
		dev_err(&pdev->dev, "failed to request low IRQ\n");
		return -ENOENT;
	}

	if (devm_request_irq(&pdev->dev, irq[1]->start,
			     em_gio_irq_handler, 0, name, p)) {
		dev_err(&pdev->dev, "failed to request high IRQ\n");
		return -ENOENT;
	}

	ret = devm_gpiochip_add_data(&pdev->dev, gpio_chip, p);
	if (ret) {
		dev_err(&pdev->dev, "failed to add GPIO controller\n");
		return ret;
	}

	return 0;
}

static const struct of_device_id em_gio_dt_ids[] = {
	{ .compatible = "renesas,em-gio", },
	{},
};
MODULE_DEVICE_TABLE(of, em_gio_dt_ids);

static struct platform_driver em_gio_device_driver = {
	.probe		= em_gio_probe,
	.driver		= {
		.name	= "em_gio",
		.of_match_table = em_gio_dt_ids,
	}
};

static int __init em_gio_init(void)
{
	return platform_driver_register(&em_gio_device_driver);
}
postcore_initcall(em_gio_init);

static void __exit em_gio_exit(void)
{
	platform_driver_unregister(&em_gio_device_driver);
}
module_exit(em_gio_exit);

MODULE_AUTHOR("Magnus Damm");
MODULE_DESCRIPTION("Renesas Emma Mobile GIO Driver");
MODULE_LICENSE("GPL v2");