xref: /linux/drivers/gpio/gpio-tc3589x.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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/irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/interrupt.h>
18 #include <linux/mfd/tc3589x.h>
19 
20 /*
21  * These registers are modified under the irq bus lock and cached to avoid
22  * unnecessary writes in bus_sync_unlock.
23  */
24 enum { REG_IBE, REG_IEV, REG_IS, REG_IE };
25 
26 #define CACHE_NR_REGS	4
27 #define CACHE_NR_BANKS	3
28 
29 struct tc3589x_gpio {
30 	struct gpio_chip chip;
31 	struct tc3589x *tc3589x;
32 	struct device *dev;
33 	struct mutex irq_lock;
34 	struct irq_domain *domain;
35 
36 	int irq_base;
37 
38 	/* Caches of interrupt control registers for bus_lock */
39 	u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
40 	u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
41 };
42 
43 static inline struct tc3589x_gpio *to_tc3589x_gpio(struct gpio_chip *chip)
44 {
45 	return container_of(chip, struct tc3589x_gpio, chip);
46 }
47 
48 static int tc3589x_gpio_get(struct gpio_chip *chip, unsigned offset)
49 {
50 	struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
51 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
52 	u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
53 	u8 mask = 1 << (offset % 8);
54 	int ret;
55 
56 	ret = tc3589x_reg_read(tc3589x, reg);
57 	if (ret < 0)
58 		return ret;
59 
60 	return ret & mask;
61 }
62 
63 static void tc3589x_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
64 {
65 	struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
66 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
67 	u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
68 	unsigned pos = offset % 8;
69 	u8 data[] = {!!val << pos, 1 << pos};
70 
71 	tc3589x_block_write(tc3589x, reg, ARRAY_SIZE(data), data);
72 }
73 
74 static int tc3589x_gpio_direction_output(struct gpio_chip *chip,
75 					 unsigned offset, int val)
76 {
77 	struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
78 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
79 	u8 reg = TC3589x_GPIODIR0 + offset / 8;
80 	unsigned pos = offset % 8;
81 
82 	tc3589x_gpio_set(chip, offset, val);
83 
84 	return tc3589x_set_bits(tc3589x, reg, 1 << pos, 1 << pos);
85 }
86 
87 static int tc3589x_gpio_direction_input(struct gpio_chip *chip,
88 					unsigned offset)
89 {
90 	struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
91 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
92 	u8 reg = TC3589x_GPIODIR0 + offset / 8;
93 	unsigned pos = offset % 8;
94 
95 	return tc3589x_set_bits(tc3589x, reg, 1 << pos, 0);
96 }
97 
98 /**
99  * tc3589x_gpio_irq_get_virq(): Map an interrupt on a chip to a virtual IRQ
100  *
101  * @tc3589x_gpio: tc3589x_gpio_irq controller to operate on.
102  * @irq: index of the interrupt requested in the chip IRQs
103  *
104  * Useful for drivers to request their own IRQs.
105  */
106 static int tc3589x_gpio_irq_get_virq(struct tc3589x_gpio *tc3589x_gpio,
107 				     int irq)
108 {
109 	if (!tc3589x_gpio)
110 		return -EINVAL;
111 
112 	return irq_create_mapping(tc3589x_gpio->domain, irq);
113 }
114 
115 static int tc3589x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
116 {
117 	struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
118 
119 	return tc3589x_gpio_irq_get_virq(tc3589x_gpio, offset);
120 }
121 
122 static struct gpio_chip template_chip = {
123 	.label			= "tc3589x",
124 	.owner			= THIS_MODULE,
125 	.direction_input	= tc3589x_gpio_direction_input,
126 	.get			= tc3589x_gpio_get,
127 	.direction_output	= tc3589x_gpio_direction_output,
128 	.set			= tc3589x_gpio_set,
129 	.to_irq			= tc3589x_gpio_to_irq,
130 	.can_sleep		= 1,
131 };
132 
133 static int tc3589x_gpio_irq_set_type(struct irq_data *d, unsigned int type)
134 {
135 	struct tc3589x_gpio *tc3589x_gpio = irq_data_get_irq_chip_data(d);
136 	int offset = d->hwirq;
137 	int regoffset = offset / 8;
138 	int mask = 1 << (offset % 8);
139 
140 	if (type == IRQ_TYPE_EDGE_BOTH) {
141 		tc3589x_gpio->regs[REG_IBE][regoffset] |= mask;
142 		return 0;
143 	}
144 
145 	tc3589x_gpio->regs[REG_IBE][regoffset] &= ~mask;
146 
147 	if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
148 		tc3589x_gpio->regs[REG_IS][regoffset] |= mask;
149 	else
150 		tc3589x_gpio->regs[REG_IS][regoffset] &= ~mask;
151 
152 	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
153 		tc3589x_gpio->regs[REG_IEV][regoffset] |= mask;
154 	else
155 		tc3589x_gpio->regs[REG_IEV][regoffset] &= ~mask;
156 
157 	return 0;
158 }
159 
160 static void tc3589x_gpio_irq_lock(struct irq_data *d)
161 {
162 	struct tc3589x_gpio *tc3589x_gpio = irq_data_get_irq_chip_data(d);
163 
164 	mutex_lock(&tc3589x_gpio->irq_lock);
165 }
166 
167 static void tc3589x_gpio_irq_sync_unlock(struct irq_data *d)
168 {
169 	struct tc3589x_gpio *tc3589x_gpio = irq_data_get_irq_chip_data(d);
170 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
171 	static const u8 regmap[] = {
172 		[REG_IBE]	= TC3589x_GPIOIBE0,
173 		[REG_IEV]	= TC3589x_GPIOIEV0,
174 		[REG_IS]	= TC3589x_GPIOIS0,
175 		[REG_IE]	= TC3589x_GPIOIE0,
176 	};
177 	int i, j;
178 
179 	for (i = 0; i < CACHE_NR_REGS; i++) {
180 		for (j = 0; j < CACHE_NR_BANKS; j++) {
181 			u8 old = tc3589x_gpio->oldregs[i][j];
182 			u8 new = tc3589x_gpio->regs[i][j];
183 
184 			if (new == old)
185 				continue;
186 
187 			tc3589x_gpio->oldregs[i][j] = new;
188 			tc3589x_reg_write(tc3589x, regmap[i] + j * 8, new);
189 		}
190 	}
191 
192 	mutex_unlock(&tc3589x_gpio->irq_lock);
193 }
194 
195 static void tc3589x_gpio_irq_mask(struct irq_data *d)
196 {
197 	struct tc3589x_gpio *tc3589x_gpio = irq_data_get_irq_chip_data(d);
198 	int offset = d->hwirq;
199 	int regoffset = offset / 8;
200 	int mask = 1 << (offset % 8);
201 
202 	tc3589x_gpio->regs[REG_IE][regoffset] &= ~mask;
203 }
204 
205 static void tc3589x_gpio_irq_unmask(struct irq_data *d)
206 {
207 	struct tc3589x_gpio *tc3589x_gpio = irq_data_get_irq_chip_data(d);
208 	int offset = d->hwirq;
209 	int regoffset = offset / 8;
210 	int mask = 1 << (offset % 8);
211 
212 	tc3589x_gpio->regs[REG_IE][regoffset] |= mask;
213 }
214 
215 static struct irq_chip tc3589x_gpio_irq_chip = {
216 	.name			= "tc3589x-gpio",
217 	.irq_bus_lock		= tc3589x_gpio_irq_lock,
218 	.irq_bus_sync_unlock	= tc3589x_gpio_irq_sync_unlock,
219 	.irq_mask		= tc3589x_gpio_irq_mask,
220 	.irq_unmask		= tc3589x_gpio_irq_unmask,
221 	.irq_set_type		= tc3589x_gpio_irq_set_type,
222 };
223 
224 static irqreturn_t tc3589x_gpio_irq(int irq, void *dev)
225 {
226 	struct tc3589x_gpio *tc3589x_gpio = dev;
227 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
228 	u8 status[CACHE_NR_BANKS];
229 	int ret;
230 	int i;
231 
232 	ret = tc3589x_block_read(tc3589x, TC3589x_GPIOMIS0,
233 				 ARRAY_SIZE(status), status);
234 	if (ret < 0)
235 		return IRQ_NONE;
236 
237 	for (i = 0; i < ARRAY_SIZE(status); i++) {
238 		unsigned int stat = status[i];
239 		if (!stat)
240 			continue;
241 
242 		while (stat) {
243 			int bit = __ffs(stat);
244 			int line = i * 8 + bit;
245 			int virq = tc3589x_gpio_irq_get_virq(tc3589x_gpio, line);
246 
247 			handle_nested_irq(virq);
248 			stat &= ~(1 << bit);
249 		}
250 
251 		tc3589x_reg_write(tc3589x, TC3589x_GPIOIC0 + i, status[i]);
252 	}
253 
254 	return IRQ_HANDLED;
255 }
256 
257 static int tc3589x_gpio_irq_map(struct irq_domain *d, unsigned int virq,
258 				irq_hw_number_t hwirq)
259 {
260 	struct tc3589x *tc3589x_gpio = d->host_data;
261 
262 	irq_set_chip_data(virq, tc3589x_gpio);
263 	irq_set_chip_and_handler(virq, &tc3589x_gpio_irq_chip,
264 				handle_simple_irq);
265 	irq_set_nested_thread(virq, 1);
266 #ifdef CONFIG_ARM
267 	set_irq_flags(virq, IRQF_VALID);
268 #else
269 	irq_set_noprobe(virq);
270 #endif
271 
272 	return 0;
273 }
274 
275 static void tc3589x_gpio_irq_unmap(struct irq_domain *d, unsigned int virq)
276 {
277 #ifdef CONFIG_ARM
278 	set_irq_flags(virq, 0);
279 #endif
280 	irq_set_chip_and_handler(virq, NULL, NULL);
281 	irq_set_chip_data(virq, NULL);
282 }
283 
284 static struct irq_domain_ops tc3589x_irq_ops = {
285         .map    = tc3589x_gpio_irq_map,
286         .unmap  = tc3589x_gpio_irq_unmap,
287         .xlate  = irq_domain_xlate_twocell,
288 };
289 
290 static int tc3589x_gpio_irq_init(struct tc3589x_gpio *tc3589x_gpio,
291 				struct device_node *np)
292 {
293 	int base = tc3589x_gpio->irq_base;
294 
295 	/*
296 	 * If this results in a linear domain, irq_create_mapping() will
297 	 * take care of allocating IRQ descriptors at runtime. When a base
298 	 * is provided, the IRQ descriptors will be allocated when the
299 	 * domain is instantiated.
300 	 */
301 	tc3589x_gpio->domain = irq_domain_add_simple(np,
302 			tc3589x_gpio->chip.ngpio, base, &tc3589x_irq_ops,
303 			tc3589x_gpio);
304 	if (!tc3589x_gpio->domain) {
305 		dev_err(tc3589x_gpio->dev, "Failed to create irqdomain\n");
306 		return -ENOSYS;
307 	}
308 
309 	return 0;
310 }
311 
312 static int tc3589x_gpio_probe(struct platform_device *pdev)
313 {
314 	struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
315 	struct tc3589x_gpio_platform_data *pdata;
316 	struct device_node *np = pdev->dev.of_node;
317 	struct tc3589x_gpio *tc3589x_gpio;
318 	int ret;
319 	int irq;
320 
321 	pdata = tc3589x->pdata->gpio;
322 
323 	if (!(pdata || np)) {
324 		dev_err(&pdev->dev, "No platform data or Device Tree found\n");
325 		return -EINVAL;
326 	}
327 
328 	irq = platform_get_irq(pdev, 0);
329 	if (irq < 0)
330 		return irq;
331 
332 	tc3589x_gpio = kzalloc(sizeof(struct tc3589x_gpio), GFP_KERNEL);
333 	if (!tc3589x_gpio)
334 		return -ENOMEM;
335 
336 	mutex_init(&tc3589x_gpio->irq_lock);
337 
338 	tc3589x_gpio->dev = &pdev->dev;
339 	tc3589x_gpio->tc3589x = tc3589x;
340 
341 	tc3589x_gpio->chip = template_chip;
342 	tc3589x_gpio->chip.ngpio = tc3589x->num_gpio;
343 	tc3589x_gpio->chip.dev = &pdev->dev;
344 	tc3589x_gpio->chip.base = (pdata) ? pdata->gpio_base : -1;
345 
346 #ifdef CONFIG_OF_GPIO
347         tc3589x_gpio->chip.of_node = np;
348 #endif
349 
350 	tc3589x_gpio->irq_base = tc3589x->irq_base ?
351 		tc3589x->irq_base + TC3589x_INT_GPIO(0) : 0;
352 
353 	/* Bring the GPIO module out of reset */
354 	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL,
355 			       TC3589x_RSTCTRL_GPIRST, 0);
356 	if (ret < 0)
357 		goto out_free;
358 
359 	ret = tc3589x_gpio_irq_init(tc3589x_gpio, np);
360 	if (ret)
361 		goto out_free;
362 
363 	ret = request_threaded_irq(irq, NULL, tc3589x_gpio_irq, IRQF_ONESHOT,
364 				   "tc3589x-gpio", tc3589x_gpio);
365 	if (ret) {
366 		dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
367 		goto out_free;
368 	}
369 
370 	ret = gpiochip_add(&tc3589x_gpio->chip);
371 	if (ret) {
372 		dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
373 		goto out_freeirq;
374 	}
375 
376 	if (pdata && pdata->setup)
377 		pdata->setup(tc3589x, tc3589x_gpio->chip.base);
378 
379 	platform_set_drvdata(pdev, tc3589x_gpio);
380 
381 	return 0;
382 
383 out_freeirq:
384 	free_irq(irq, tc3589x_gpio);
385 out_free:
386 	kfree(tc3589x_gpio);
387 	return ret;
388 }
389 
390 static int tc3589x_gpio_remove(struct platform_device *pdev)
391 {
392 	struct tc3589x_gpio *tc3589x_gpio = platform_get_drvdata(pdev);
393 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
394 	struct tc3589x_gpio_platform_data *pdata = tc3589x->pdata->gpio;
395 	int irq = platform_get_irq(pdev, 0);
396 	int ret;
397 
398 	if (pdata && pdata->remove)
399 		pdata->remove(tc3589x, tc3589x_gpio->chip.base);
400 
401 	ret = gpiochip_remove(&tc3589x_gpio->chip);
402 	if (ret < 0) {
403 		dev_err(tc3589x_gpio->dev,
404 			"unable to remove gpiochip: %d\n", ret);
405 		return ret;
406 	}
407 
408 	free_irq(irq, tc3589x_gpio);
409 
410 	platform_set_drvdata(pdev, NULL);
411 	kfree(tc3589x_gpio);
412 
413 	return 0;
414 }
415 
416 static struct platform_driver tc3589x_gpio_driver = {
417 	.driver.name	= "tc3589x-gpio",
418 	.driver.owner	= THIS_MODULE,
419 	.probe		= tc3589x_gpio_probe,
420 	.remove		= tc3589x_gpio_remove,
421 };
422 
423 static int __init tc3589x_gpio_init(void)
424 {
425 	return platform_driver_register(&tc3589x_gpio_driver);
426 }
427 subsys_initcall(tc3589x_gpio_init);
428 
429 static void __exit tc3589x_gpio_exit(void)
430 {
431 	platform_driver_unregister(&tc3589x_gpio_driver);
432 }
433 module_exit(tc3589x_gpio_exit);
434 
435 MODULE_LICENSE("GPL v2");
436 MODULE_DESCRIPTION("TC3589x GPIO driver");
437 MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");
438