File: gpio-tb10x.c

package info (click to toggle)
linux 4.19.20-1
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 954,852 kB
  • sloc: ansic: 16,749,828; asm: 271,286; makefile: 38,257; sh: 32,808; perl: 27,671; python: 21,022; cpp: 5,063; yacc: 4,648; lex: 2,585; awk: 1,385; ruby: 25; sed: 5
file content (297 lines) | stat: -rw-r--r-- 8,189 bytes parent folder | download | duplicates (7)
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
/* Abilis Systems MODULE DESCRIPTION
 *
 * Copyright (C) Abilis Systems 2013
 *
 * Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com>
 *          Christian Ruppert <christian.ruppert@abilis.com>
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/spinlock.h>
#include <linux/bitops.h>
#include <linux/pinctrl/consumer.h>

#define TB10X_GPIO_DIR_IN	(0x00000000)
#define TB10X_GPIO_DIR_OUT	(0x00000001)
#define OFFSET_TO_REG_DDR	(0x00)
#define OFFSET_TO_REG_DATA	(0x04)
#define OFFSET_TO_REG_INT_EN	(0x08)
#define OFFSET_TO_REG_CHANGE	(0x0C)
#define OFFSET_TO_REG_WRMASK	(0x10)
#define OFFSET_TO_REG_INT_TYPE	(0x14)


/**
 * @spinlock: used for atomic read/modify/write of registers
 * @base: register base address
 * @domain: IRQ domain of GPIO generated interrupts managed by this controller
 * @irq: Interrupt line of parent interrupt controller
 * @gc: gpio_chip structure associated to this GPIO controller
 */
struct tb10x_gpio {
	spinlock_t spinlock;
	void __iomem *base;
	struct irq_domain *domain;
	int irq;
	struct gpio_chip gc;
};

static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs)
{
	return ioread32(gpio->base + offs);
}

static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs,
				u32 val)
{
	iowrite32(val, gpio->base + offs);
}

static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs,
				u32 mask, u32 val)
{
	u32 r;
	unsigned long flags;

	spin_lock_irqsave(&gpio->spinlock, flags);

	r = tb10x_reg_read(gpio, offs);
	r = (r & ~mask) | (val & mask);

	tb10x_reg_write(gpio, offs, r);

	spin_unlock_irqrestore(&gpio->spinlock, flags);
}

static int tb10x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
{
	struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
	int mask = BIT(offset);
	int val = TB10X_GPIO_DIR_IN << offset;

	tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);

	return 0;
}

static int tb10x_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
	int val;

	val = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_DATA);

	if (val & BIT(offset))
		return 1;
	else
		return 0;
}

static void tb10x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
	int mask = BIT(offset);
	int val = value << offset;

	tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DATA, mask, val);
}

static int tb10x_gpio_direction_out(struct gpio_chip *chip,
					unsigned offset, int value)
{
	struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
	int mask = BIT(offset);
	int val = TB10X_GPIO_DIR_OUT << offset;

	tb10x_gpio_set(chip, offset, value);
	tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);

	return 0;
}

static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
	struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);

	return irq_create_mapping(tb10x_gpio->domain, offset);
}

static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
{
	if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
		pr_err("Only (both) edge triggered interrupts supported.\n");
		return -EINVAL;
	}

	irqd_set_trigger_type(data, type);

	return IRQ_SET_MASK_OK;
}

static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
{
	struct tb10x_gpio *tb10x_gpio = data;
	u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
	u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
	const unsigned long bits = r & m;
	int i;

	for_each_set_bit(i, &bits, 32)
		generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i));

	return IRQ_HANDLED;
}

static int tb10x_gpio_probe(struct platform_device *pdev)
{
	struct tb10x_gpio *tb10x_gpio;
	struct resource *mem;
	struct device_node *dn = pdev->dev.of_node;
	int ret = -EBUSY;
	u32 ngpio;

	if (!dn)
		return -EINVAL;

	if (of_property_read_u32(dn, "abilis,ngpio", &ngpio))
		return -EINVAL;

	tb10x_gpio = devm_kzalloc(&pdev->dev, sizeof(*tb10x_gpio), GFP_KERNEL);
	if (tb10x_gpio == NULL)
		return -ENOMEM;

	spin_lock_init(&tb10x_gpio->spinlock);

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	tb10x_gpio->base = devm_ioremap_resource(&pdev->dev, mem);
	if (IS_ERR(tb10x_gpio->base))
		return PTR_ERR(tb10x_gpio->base);

	tb10x_gpio->gc.label		=
		devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOF", pdev->dev.of_node);
	if (!tb10x_gpio->gc.label)
		return -ENOMEM;

	tb10x_gpio->gc.parent		= &pdev->dev;
	tb10x_gpio->gc.owner		= THIS_MODULE;
	tb10x_gpio->gc.direction_input	= tb10x_gpio_direction_in;
	tb10x_gpio->gc.get		= tb10x_gpio_get;
	tb10x_gpio->gc.direction_output	= tb10x_gpio_direction_out;
	tb10x_gpio->gc.set		= tb10x_gpio_set;
	tb10x_gpio->gc.request		= gpiochip_generic_request;
	tb10x_gpio->gc.free		= gpiochip_generic_free;
	tb10x_gpio->gc.base		= -1;
	tb10x_gpio->gc.ngpio		= ngpio;
	tb10x_gpio->gc.can_sleep	= false;


	ret = devm_gpiochip_add_data(&pdev->dev, &tb10x_gpio->gc, tb10x_gpio);
	if (ret < 0) {
		dev_err(&pdev->dev, "Could not add gpiochip.\n");
		return ret;
	}

	platform_set_drvdata(pdev, tb10x_gpio);

	if (of_find_property(dn, "interrupt-controller", NULL)) {
		struct irq_chip_generic *gc;

		ret = platform_get_irq(pdev, 0);
		if (ret < 0) {
			dev_err(&pdev->dev, "No interrupt specified.\n");
			return ret;
		}

		tb10x_gpio->gc.to_irq	= tb10x_gpio_to_irq;
		tb10x_gpio->irq		= ret;

		ret = devm_request_irq(&pdev->dev, ret, tb10x_gpio_irq_cascade,
				IRQF_TRIGGER_NONE | IRQF_SHARED,
				dev_name(&pdev->dev), tb10x_gpio);
		if (ret != 0)
			return ret;

		tb10x_gpio->domain = irq_domain_add_linear(dn,
						tb10x_gpio->gc.ngpio,
						&irq_generic_chip_ops, NULL);
		if (!tb10x_gpio->domain) {
			return -ENOMEM;
		}

		ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
				tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
				handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
				IRQ_GC_INIT_MASK_CACHE);
		if (ret)
			return ret;

		gc = tb10x_gpio->domain->gc->gc[0];
		gc->reg_base                         = tb10x_gpio->base;
		gc->chip_types[0].type               = IRQ_TYPE_EDGE_BOTH;
		gc->chip_types[0].chip.irq_ack       = irq_gc_ack_set_bit;
		gc->chip_types[0].chip.irq_mask      = irq_gc_mask_clr_bit;
		gc->chip_types[0].chip.irq_unmask    = irq_gc_mask_set_bit;
		gc->chip_types[0].chip.irq_set_type  = tb10x_gpio_irq_set_type;
		gc->chip_types[0].regs.ack           = OFFSET_TO_REG_CHANGE;
		gc->chip_types[0].regs.mask          = OFFSET_TO_REG_INT_EN;
	}

	return 0;
}

static int tb10x_gpio_remove(struct platform_device *pdev)
{
	struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);

	if (tb10x_gpio->gc.to_irq) {
		irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
					BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0);
		kfree(tb10x_gpio->domain->gc);
		irq_domain_remove(tb10x_gpio->domain);
	}

	return 0;
}

static const struct of_device_id tb10x_gpio_dt_ids[] = {
	{ .compatible = "abilis,tb10x-gpio" },
	{ }
};
MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);

static struct platform_driver tb10x_gpio_driver = {
	.probe		= tb10x_gpio_probe,
	.remove		= tb10x_gpio_remove,
	.driver = {
		.name	= "tb10x-gpio",
		.of_match_table = tb10x_gpio_dt_ids,
	}
};

module_platform_driver(tb10x_gpio_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("tb10x gpio.");
MODULE_VERSION("0.0.1");