1/*
2 * ZTE ZX296702 GPIO driver
3 *
4 * Author: Jun Nie <jun.nie@linaro.org>
5 *
6 * Copyright (C) 2015 Linaro Ltd.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/bitops.h>
13#include <linux/device.h>
14#include <linux/errno.h>
15#include <linux/gpio/driver.h>
16#include <linux/irqchip/chained_irq.h>
17#include <linux/init.h>
18#include <linux/of.h>
19#include <linux/pinctrl/consumer.h>
20#include <linux/platform_device.h>
21#include <linux/pm.h>
22#include <linux/slab.h>
23#include <linux/spinlock.h>
24
25#define ZX_GPIO_DIR 0x00
26#define ZX_GPIO_IVE 0x04
27#define ZX_GPIO_IV 0x08
28#define ZX_GPIO_IEP 0x0C
29#define ZX_GPIO_IEN 0x10
30#define ZX_GPIO_DI 0x14
31#define ZX_GPIO_DO1 0x18
32#define ZX_GPIO_DO0 0x1C
33#define ZX_GPIO_DO 0x20
34
35#define ZX_GPIO_IM 0x28
36#define ZX_GPIO_IE 0x2C
37
38#define ZX_GPIO_MIS 0x30
39#define ZX_GPIO_IC 0x34
40
41#define ZX_GPIO_NR 16
42
43struct zx_gpio {
44 raw_spinlock_t lock;
45
46 void __iomem *base;
47 struct gpio_chip gc;
48};
49
50static int zx_direction_input(struct gpio_chip *gc, unsigned offset)
51{
52 struct zx_gpio *chip = gpiochip_get_data(gc);
53 unsigned long flags;
54 u16 gpiodir;
55
56 if (offset >= gc->ngpio)
57 return -EINVAL;
58
59 raw_spin_lock_irqsave(&chip->lock, flags);
60 gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR);
61 gpiodir &= ~BIT(offset);
62 writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR);
63 raw_spin_unlock_irqrestore(&chip->lock, flags);
64
65 return 0;
66}
67
68static int zx_direction_output(struct gpio_chip *gc, unsigned offset,
69 int value)
70{
71 struct zx_gpio *chip = gpiochip_get_data(gc);
72 unsigned long flags;
73 u16 gpiodir;
74
75 if (offset >= gc->ngpio)
76 return -EINVAL;
77
78 raw_spin_lock_irqsave(&chip->lock, flags);
79 gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR);
80 gpiodir |= BIT(offset);
81 writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR);
82
83 if (value)
84 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1);
85 else
86 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0);
87 raw_spin_unlock_irqrestore(&chip->lock, flags);
88
89 return 0;
90}
91
92static int zx_get_value(struct gpio_chip *gc, unsigned offset)
93{
94 struct zx_gpio *chip = gpiochip_get_data(gc);
95
96 return !!(readw_relaxed(chip->base + ZX_GPIO_DI) & BIT(offset));
97}
98
99static void zx_set_value(struct gpio_chip *gc, unsigned offset, int value)
100{
101 struct zx_gpio *chip = gpiochip_get_data(gc);
102
103 if (value)
104 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1);
105 else
106 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0);
107}
108
109static int zx_irq_type(struct irq_data *d, unsigned trigger)
110{
111 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
112 struct zx_gpio *chip = gpiochip_get_data(gc);
113 int offset = irqd_to_hwirq(d);
114 unsigned long flags;
115 u16 gpiois, gpioi_epos, gpioi_eneg, gpioiev;
116 u16 bit = BIT(offset);
117
118 if (offset < 0 || offset >= ZX_GPIO_NR)
119 return -EINVAL;
120
121 raw_spin_lock_irqsave(&chip->lock, flags);
122
123 gpioiev = readw_relaxed(chip->base + ZX_GPIO_IV);
124 gpiois = readw_relaxed(chip->base + ZX_GPIO_IVE);
125 gpioi_epos = readw_relaxed(chip->base + ZX_GPIO_IEP);
126 gpioi_eneg = readw_relaxed(chip->base + ZX_GPIO_IEN);
127
128 if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
129 gpiois |= bit;
130 if (trigger & IRQ_TYPE_LEVEL_HIGH)
131 gpioiev |= bit;
132 else
133 gpioiev &= ~bit;
134 } else
135 gpiois &= ~bit;
136
137 if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
138 gpioi_epos |= bit;
139 gpioi_eneg |= bit;
140 } else {
141 if (trigger & IRQ_TYPE_EDGE_RISING) {
142 gpioi_epos |= bit;
143 gpioi_eneg &= ~bit;
144 } else if (trigger & IRQ_TYPE_EDGE_FALLING) {
145 gpioi_eneg |= bit;
146 gpioi_epos &= ~bit;
147 }
148 }
149
150 writew_relaxed(gpiois, chip->base + ZX_GPIO_IVE);
151 writew_relaxed(gpioi_epos, chip->base + ZX_GPIO_IEP);
152 writew_relaxed(gpioi_eneg, chip->base + ZX_GPIO_IEN);
153 writew_relaxed(gpioiev, chip->base + ZX_GPIO_IV);
154 raw_spin_unlock_irqrestore(&chip->lock, flags);
155
156 return 0;
157}
158
159static void zx_irq_handler(struct irq_desc *desc)
160{
161 unsigned long pending;
162 int offset;
163 struct gpio_chip *gc = irq_desc_get_handler_data(desc);
164 struct zx_gpio *chip = gpiochip_get_data(gc);
165 struct irq_chip *irqchip = irq_desc_get_chip(desc);
166
167 chained_irq_enter(irqchip, desc);
168
169 pending = readw_relaxed(chip->base + ZX_GPIO_MIS);
170 writew_relaxed(pending, chip->base + ZX_GPIO_IC);
171 if (pending) {
172 for_each_set_bit(offset, &pending, ZX_GPIO_NR)
173 generic_handle_irq(irq_find_mapping(gc->irq.domain,
174 offset));
175 }
176
177 chained_irq_exit(irqchip, desc);
178}
179
180static void zx_irq_mask(struct irq_data *d)
181{
182 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
183 struct zx_gpio *chip = gpiochip_get_data(gc);
184 u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR);
185 u16 gpioie;
186
187 raw_spin_lock(&chip->lock);
188 gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) | mask;
189 writew_relaxed(gpioie, chip->base + ZX_GPIO_IM);
190 gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) & ~mask;
191 writew_relaxed(gpioie, chip->base + ZX_GPIO_IE);
192 raw_spin_unlock(&chip->lock);
193}
194
195static void zx_irq_unmask(struct irq_data *d)
196{
197 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
198 struct zx_gpio *chip = gpiochip_get_data(gc);
199 u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR);
200 u16 gpioie;
201
202 raw_spin_lock(&chip->lock);
203 gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) & ~mask;
204 writew_relaxed(gpioie, chip->base + ZX_GPIO_IM);
205 gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) | mask;
206 writew_relaxed(gpioie, chip->base + ZX_GPIO_IE);
207 raw_spin_unlock(&chip->lock);
208}
209
210static struct irq_chip zx_irqchip = {
211 .name = "zx-gpio",
212 .irq_mask = zx_irq_mask,
213 .irq_unmask = zx_irq_unmask,
214 .irq_set_type = zx_irq_type,
215};
216
217static int zx_gpio_probe(struct platform_device *pdev)
218{
219 struct device *dev = &pdev->dev;
220 struct zx_gpio *chip;
221 struct resource *res;
222 int irq, id, ret;
223
224 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
225 if (!chip)
226 return -ENOMEM;
227
228 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
229 chip->base = devm_ioremap_resource(dev, res);
230 if (IS_ERR(chip->base))
231 return PTR_ERR(chip->base);
232
233 raw_spin_lock_init(&chip->lock);
234 if (of_property_read_bool(dev->of_node, "gpio-ranges")) {
235 chip->gc.request = gpiochip_generic_request;
236 chip->gc.free = gpiochip_generic_free;
237 }
238
239 id = of_alias_get_id(dev->of_node, "gpio");
240 chip->gc.direction_input = zx_direction_input;
241 chip->gc.direction_output = zx_direction_output;
242 chip->gc.get = zx_get_value;
243 chip->gc.set = zx_set_value;
244 chip->gc.base = ZX_GPIO_NR * id;
245 chip->gc.ngpio = ZX_GPIO_NR;
246 chip->gc.label = dev_name(dev);
247 chip->gc.parent = dev;
248 chip->gc.owner = THIS_MODULE;
249
250 ret = gpiochip_add_data(&chip->gc, chip);
251 if (ret)
252 return ret;
253
254 /*
255 * irq_chip support
256 */
257 writew_relaxed(0xffff, chip->base + ZX_GPIO_IM);
258 writew_relaxed(0, chip->base + ZX_GPIO_IE);
259 irq = platform_get_irq(pdev, 0);
260 if (irq < 0) {
261 dev_err(dev, "invalid IRQ\n");
262 gpiochip_remove(&chip->gc);
263 return -ENODEV;
264 }
265
266 ret = gpiochip_irqchip_add(&chip->gc, &zx_irqchip,
267 0, handle_simple_irq,
268 IRQ_TYPE_NONE);
269 if (ret) {
270 dev_err(dev, "could not add irqchip\n");
271 gpiochip_remove(&chip->gc);
272 return ret;
273 }
274 gpiochip_set_chained_irqchip(&chip->gc, &zx_irqchip,
275 irq, zx_irq_handler);
276
277 platform_set_drvdata(pdev, chip);
278 dev_info(dev, "ZX GPIO chip registered\n");
279
280 return 0;
281}
282
283static const struct of_device_id zx_gpio_match[] = {
284 {
285 .compatible = "zte,zx296702-gpio",
286 },
287 { },
288};
289
290static struct platform_driver zx_gpio_driver = {
291 .probe = zx_gpio_probe,
292 .driver = {
293 .name = "zx_gpio",
294 .of_match_table = of_match_ptr(zx_gpio_match),
295 },
296};
297builtin_platform_driver(zx_gpio_driver)
298