xref: /linux/drivers/gpio/gpio-tc3589x.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
1 /*
2  * Copyright (C) ST-Ericsson SA 2010
3  *
4  * License Terms: GNU General Public License, version 2
5  * Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
6  * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
7  */
8 
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/platform_device.h>
12 #include <linux/slab.h>
13 #include <linux/gpio.h>
14 #include <linux/of.h>
15 #include <linux/interrupt.h>
16 #include <linux/mfd/tc3589x.h>
17 
18 /*
19  * These registers are modified under the irq bus lock and cached to avoid
20  * unnecessary writes in bus_sync_unlock.
21  */
22 enum { REG_IBE, REG_IEV, REG_IS, REG_IE };
23 
24 #define CACHE_NR_REGS	4
25 #define CACHE_NR_BANKS	3
26 
27 struct tc3589x_gpio {
28 	struct gpio_chip chip;
29 	struct tc3589x *tc3589x;
30 	struct device *dev;
31 	struct mutex irq_lock;
32 	/* Caches of interrupt control registers for bus_lock */
33 	u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
34 	u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
35 };
36 
37 static inline struct tc3589x_gpio *to_tc3589x_gpio(struct gpio_chip *chip)
38 {
39 	return container_of(chip, struct tc3589x_gpio, chip);
40 }
41 
42 static int tc3589x_gpio_get(struct gpio_chip *chip, unsigned offset)
43 {
44 	struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
45 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
46 	u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
47 	u8 mask = 1 << (offset % 8);
48 	int ret;
49 
50 	ret = tc3589x_reg_read(tc3589x, reg);
51 	if (ret < 0)
52 		return ret;
53 
54 	return ret & mask;
55 }
56 
57 static void tc3589x_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
58 {
59 	struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
60 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
61 	u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
62 	unsigned pos = offset % 8;
63 	u8 data[] = {!!val << pos, 1 << pos};
64 
65 	tc3589x_block_write(tc3589x, reg, ARRAY_SIZE(data), data);
66 }
67 
68 static int tc3589x_gpio_direction_output(struct gpio_chip *chip,
69 					 unsigned offset, int val)
70 {
71 	struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
72 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
73 	u8 reg = TC3589x_GPIODIR0 + offset / 8;
74 	unsigned pos = offset % 8;
75 
76 	tc3589x_gpio_set(chip, offset, val);
77 
78 	return tc3589x_set_bits(tc3589x, reg, 1 << pos, 1 << pos);
79 }
80 
81 static int tc3589x_gpio_direction_input(struct gpio_chip *chip,
82 					unsigned offset)
83 {
84 	struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
85 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
86 	u8 reg = TC3589x_GPIODIR0 + offset / 8;
87 	unsigned pos = offset % 8;
88 
89 	return tc3589x_set_bits(tc3589x, reg, 1 << pos, 0);
90 }
91 
92 static struct gpio_chip template_chip = {
93 	.label			= "tc3589x",
94 	.owner			= THIS_MODULE,
95 	.direction_input	= tc3589x_gpio_direction_input,
96 	.get			= tc3589x_gpio_get,
97 	.direction_output	= tc3589x_gpio_direction_output,
98 	.set			= tc3589x_gpio_set,
99 	.can_sleep		= true,
100 };
101 
102 static int tc3589x_gpio_irq_set_type(struct irq_data *d, unsigned int type)
103 {
104 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
105 	struct tc3589x_gpio *tc3589x_gpio = container_of(gc, struct tc3589x_gpio, chip);
106 	int offset = d->hwirq;
107 	int regoffset = offset / 8;
108 	int mask = 1 << (offset % 8);
109 
110 	if (type == IRQ_TYPE_EDGE_BOTH) {
111 		tc3589x_gpio->regs[REG_IBE][regoffset] |= mask;
112 		return 0;
113 	}
114 
115 	tc3589x_gpio->regs[REG_IBE][regoffset] &= ~mask;
116 
117 	if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
118 		tc3589x_gpio->regs[REG_IS][regoffset] |= mask;
119 	else
120 		tc3589x_gpio->regs[REG_IS][regoffset] &= ~mask;
121 
122 	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
123 		tc3589x_gpio->regs[REG_IEV][regoffset] |= mask;
124 	else
125 		tc3589x_gpio->regs[REG_IEV][regoffset] &= ~mask;
126 
127 	return 0;
128 }
129 
130 static void tc3589x_gpio_irq_lock(struct irq_data *d)
131 {
132 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
133 	struct tc3589x_gpio *tc3589x_gpio = container_of(gc, struct tc3589x_gpio, chip);
134 
135 	mutex_lock(&tc3589x_gpio->irq_lock);
136 }
137 
138 static void tc3589x_gpio_irq_sync_unlock(struct irq_data *d)
139 {
140 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
141 	struct tc3589x_gpio *tc3589x_gpio = container_of(gc, struct tc3589x_gpio, chip);
142 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
143 	static const u8 regmap[] = {
144 		[REG_IBE]	= TC3589x_GPIOIBE0,
145 		[REG_IEV]	= TC3589x_GPIOIEV0,
146 		[REG_IS]	= TC3589x_GPIOIS0,
147 		[REG_IE]	= TC3589x_GPIOIE0,
148 	};
149 	int i, j;
150 
151 	for (i = 0; i < CACHE_NR_REGS; i++) {
152 		for (j = 0; j < CACHE_NR_BANKS; j++) {
153 			u8 old = tc3589x_gpio->oldregs[i][j];
154 			u8 new = tc3589x_gpio->regs[i][j];
155 
156 			if (new == old)
157 				continue;
158 
159 			tc3589x_gpio->oldregs[i][j] = new;
160 			tc3589x_reg_write(tc3589x, regmap[i] + j * 8, new);
161 		}
162 	}
163 
164 	mutex_unlock(&tc3589x_gpio->irq_lock);
165 }
166 
167 static void tc3589x_gpio_irq_mask(struct irq_data *d)
168 {
169 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
170 	struct tc3589x_gpio *tc3589x_gpio = container_of(gc, struct tc3589x_gpio, chip);
171 	int offset = d->hwirq;
172 	int regoffset = offset / 8;
173 	int mask = 1 << (offset % 8);
174 
175 	tc3589x_gpio->regs[REG_IE][regoffset] &= ~mask;
176 }
177 
178 static void tc3589x_gpio_irq_unmask(struct irq_data *d)
179 {
180 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
181 	struct tc3589x_gpio *tc3589x_gpio = container_of(gc, struct tc3589x_gpio, chip);
182 	int offset = d->hwirq;
183 	int regoffset = offset / 8;
184 	int mask = 1 << (offset % 8);
185 
186 	tc3589x_gpio->regs[REG_IE][regoffset] |= mask;
187 }
188 
189 static struct irq_chip tc3589x_gpio_irq_chip = {
190 	.name			= "tc3589x-gpio",
191 	.irq_bus_lock		= tc3589x_gpio_irq_lock,
192 	.irq_bus_sync_unlock	= tc3589x_gpio_irq_sync_unlock,
193 	.irq_mask		= tc3589x_gpio_irq_mask,
194 	.irq_unmask		= tc3589x_gpio_irq_unmask,
195 	.irq_set_type		= tc3589x_gpio_irq_set_type,
196 };
197 
198 static irqreturn_t tc3589x_gpio_irq(int irq, void *dev)
199 {
200 	struct tc3589x_gpio *tc3589x_gpio = dev;
201 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
202 	u8 status[CACHE_NR_BANKS];
203 	int ret;
204 	int i;
205 
206 	ret = tc3589x_block_read(tc3589x, TC3589x_GPIOMIS0,
207 				 ARRAY_SIZE(status), status);
208 	if (ret < 0)
209 		return IRQ_NONE;
210 
211 	for (i = 0; i < ARRAY_SIZE(status); i++) {
212 		unsigned int stat = status[i];
213 		if (!stat)
214 			continue;
215 
216 		while (stat) {
217 			int bit = __ffs(stat);
218 			int line = i * 8 + bit;
219 			int irq = irq_find_mapping(tc3589x_gpio->chip.irqdomain,
220 						   line);
221 
222 			handle_nested_irq(irq);
223 			stat &= ~(1 << bit);
224 		}
225 
226 		tc3589x_reg_write(tc3589x, TC3589x_GPIOIC0 + i, status[i]);
227 	}
228 
229 	return IRQ_HANDLED;
230 }
231 
232 static int tc3589x_gpio_probe(struct platform_device *pdev)
233 {
234 	struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
235 	struct tc3589x_gpio_platform_data *pdata;
236 	struct device_node *np = pdev->dev.of_node;
237 	struct tc3589x_gpio *tc3589x_gpio;
238 	int ret;
239 	int irq;
240 
241 	pdata = tc3589x->pdata->gpio;
242 
243 	if (!(pdata || np)) {
244 		dev_err(&pdev->dev, "No platform data or Device Tree found\n");
245 		return -EINVAL;
246 	}
247 
248 	irq = platform_get_irq(pdev, 0);
249 	if (irq < 0)
250 		return irq;
251 
252 	tc3589x_gpio = devm_kzalloc(&pdev->dev, sizeof(struct tc3589x_gpio),
253 				    GFP_KERNEL);
254 	if (!tc3589x_gpio)
255 		return -ENOMEM;
256 
257 	mutex_init(&tc3589x_gpio->irq_lock);
258 
259 	tc3589x_gpio->dev = &pdev->dev;
260 	tc3589x_gpio->tc3589x = tc3589x;
261 
262 	tc3589x_gpio->chip = template_chip;
263 	tc3589x_gpio->chip.ngpio = tc3589x->num_gpio;
264 	tc3589x_gpio->chip.dev = &pdev->dev;
265 	tc3589x_gpio->chip.base = -1;
266 
267 #ifdef CONFIG_OF_GPIO
268 	tc3589x_gpio->chip.of_node = np;
269 #endif
270 
271 	/* Bring the GPIO module out of reset */
272 	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL,
273 			       TC3589x_RSTCTRL_GPIRST, 0);
274 	if (ret < 0)
275 		return ret;
276 
277 	ret = devm_request_threaded_irq(&pdev->dev,
278 					irq, NULL, tc3589x_gpio_irq,
279 					IRQF_ONESHOT, "tc3589x-gpio",
280 					tc3589x_gpio);
281 	if (ret) {
282 		dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
283 		return ret;
284 	}
285 
286 	ret = gpiochip_add(&tc3589x_gpio->chip);
287 	if (ret) {
288 		dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
289 		return ret;
290 	}
291 
292 	ret =  gpiochip_irqchip_add(&tc3589x_gpio->chip,
293 				    &tc3589x_gpio_irq_chip,
294 				    0,
295 				    handle_simple_irq,
296 				    IRQ_TYPE_NONE);
297 	if (ret) {
298 		dev_err(&pdev->dev,
299 			"could not connect irqchip to gpiochip\n");
300 		return ret;
301 	}
302 
303 	gpiochip_set_chained_irqchip(&tc3589x_gpio->chip,
304 				     &tc3589x_gpio_irq_chip,
305 				     irq,
306 				     NULL);
307 
308 	if (pdata && pdata->setup)
309 		pdata->setup(tc3589x, tc3589x_gpio->chip.base);
310 
311 	platform_set_drvdata(pdev, tc3589x_gpio);
312 
313 	return 0;
314 }
315 
316 static int tc3589x_gpio_remove(struct platform_device *pdev)
317 {
318 	struct tc3589x_gpio *tc3589x_gpio = platform_get_drvdata(pdev);
319 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
320 	struct tc3589x_gpio_platform_data *pdata = tc3589x->pdata->gpio;
321 
322 	if (pdata && pdata->remove)
323 		pdata->remove(tc3589x, tc3589x_gpio->chip.base);
324 
325 	gpiochip_remove(&tc3589x_gpio->chip);
326 
327 	return 0;
328 }
329 
330 static struct platform_driver tc3589x_gpio_driver = {
331 	.driver.name	= "tc3589x-gpio",
332 	.driver.owner	= THIS_MODULE,
333 	.probe		= tc3589x_gpio_probe,
334 	.remove		= tc3589x_gpio_remove,
335 };
336 
337 static int __init tc3589x_gpio_init(void)
338 {
339 	return platform_driver_register(&tc3589x_gpio_driver);
340 }
341 subsys_initcall(tc3589x_gpio_init);
342 
343 static void __exit tc3589x_gpio_exit(void)
344 {
345 	platform_driver_unregister(&tc3589x_gpio_driver);
346 }
347 module_exit(tc3589x_gpio_exit);
348 
349 MODULE_LICENSE("GPL v2");
350 MODULE_DESCRIPTION("TC3589x GPIO driver");
351 MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");
352