xref: /linux/drivers/gpio/gpio-tc3589x.c (revision 22c55fb9eb92395d999b8404d73e58540d11bdd8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) ST-Ericsson SA 2010
4  *
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/init.h>
10 #include <linux/platform_device.h>
11 #include <linux/slab.h>
12 #include <linux/gpio/driver.h>
13 #include <linux/of.h>
14 #include <linux/interrupt.h>
15 #include <linux/mfd/tc3589x.h>
16 #include <linux/bitops.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, REG_DIRECT };
23 
24 #define CACHE_NR_REGS	5
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 int tc3589x_gpio_get(struct gpio_chip *chip, unsigned int offset)
38 {
39 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
40 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
41 	u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
42 	u8 mask = BIT(offset % 8);
43 	int ret;
44 
45 	ret = tc3589x_reg_read(tc3589x, reg);
46 	if (ret < 0)
47 		return ret;
48 
49 	return !!(ret & mask);
50 }
51 
52 static int tc3589x_gpio_set(struct gpio_chip *chip, unsigned int offset, int val)
53 {
54 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
55 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
56 	u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
57 	unsigned int pos = offset % 8;
58 	u8 data[] = {val ? BIT(pos) : 0, BIT(pos)};
59 
60 	return tc3589x_block_write(tc3589x, reg, ARRAY_SIZE(data), data);
61 }
62 
63 static int tc3589x_gpio_direction_output(struct gpio_chip *chip,
64 					 unsigned int offset, int val)
65 {
66 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
67 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
68 	u8 reg = TC3589x_GPIODIR0 + offset / 8;
69 	unsigned int pos = offset % 8;
70 	int ret;
71 
72 	ret = tc3589x_gpio_set(chip, offset, val);
73 	if (ret)
74 		return ret;
75 
76 	return tc3589x_set_bits(tc3589x, reg, BIT(pos), BIT(pos));
77 }
78 
79 static int tc3589x_gpio_direction_input(struct gpio_chip *chip,
80 					unsigned int offset)
81 {
82 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
83 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
84 	u8 reg = TC3589x_GPIODIR0 + offset / 8;
85 	unsigned int pos = offset % 8;
86 
87 	return tc3589x_set_bits(tc3589x, reg, BIT(pos), 0);
88 }
89 
90 static int tc3589x_gpio_get_direction(struct gpio_chip *chip,
91 				      unsigned int offset)
92 {
93 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
94 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
95 	u8 reg = TC3589x_GPIODIR0 + offset / 8;
96 	unsigned int pos = offset % 8;
97 	int ret;
98 
99 	ret = tc3589x_reg_read(tc3589x, reg);
100 	if (ret < 0)
101 		return ret;
102 
103 	if (ret & BIT(pos))
104 		return GPIO_LINE_DIRECTION_OUT;
105 
106 	return GPIO_LINE_DIRECTION_IN;
107 }
108 
109 static int tc3589x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
110 				   unsigned long config)
111 {
112 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
113 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
114 	/*
115 	 * These registers are alterated at each second address
116 	 * ODM bit 0 = drive to GND or Hi-Z (open drain)
117 	 * ODM bit 1 = drive to VDD or Hi-Z (open source)
118 	 */
119 	u8 odmreg = TC3589x_GPIOODM0 + (offset / 8) * 2;
120 	u8 odereg = TC3589x_GPIOODE0 + (offset / 8) * 2;
121 	unsigned int pos = offset % 8;
122 	int ret;
123 
124 	switch (pinconf_to_config_param(config)) {
125 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
126 		/* Set open drain mode */
127 		ret = tc3589x_set_bits(tc3589x, odmreg, BIT(pos), 0);
128 		if (ret)
129 			return ret;
130 		/* Enable open drain/source mode */
131 		return tc3589x_set_bits(tc3589x, odereg, BIT(pos), BIT(pos));
132 	case PIN_CONFIG_DRIVE_OPEN_SOURCE:
133 		/* Set open source mode */
134 		ret = tc3589x_set_bits(tc3589x, odmreg, BIT(pos), BIT(pos));
135 		if (ret)
136 			return ret;
137 		/* Enable open drain/source mode */
138 		return tc3589x_set_bits(tc3589x, odereg, BIT(pos), BIT(pos));
139 	case PIN_CONFIG_DRIVE_PUSH_PULL:
140 		/* Disable open drain/source mode */
141 		return tc3589x_set_bits(tc3589x, odereg, BIT(pos), 0);
142 	default:
143 		break;
144 	}
145 	return -ENOTSUPP;
146 }
147 
148 static const struct gpio_chip template_chip = {
149 	.label			= "tc3589x",
150 	.owner			= THIS_MODULE,
151 	.get			= tc3589x_gpio_get,
152 	.set			= tc3589x_gpio_set,
153 	.direction_output	= tc3589x_gpio_direction_output,
154 	.direction_input	= tc3589x_gpio_direction_input,
155 	.get_direction		= tc3589x_gpio_get_direction,
156 	.set_config		= tc3589x_gpio_set_config,
157 	.can_sleep		= true,
158 };
159 
160 static int tc3589x_gpio_irq_set_type(struct irq_data *d, unsigned int type)
161 {
162 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
163 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
164 	int offset = d->hwirq;
165 	int regoffset = offset / 8;
166 	int mask = BIT(offset % 8);
167 
168 	if (type == IRQ_TYPE_EDGE_BOTH) {
169 		tc3589x_gpio->regs[REG_IBE][regoffset] |= mask;
170 		return 0;
171 	}
172 
173 	tc3589x_gpio->regs[REG_IBE][regoffset] &= ~mask;
174 
175 	if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
176 		tc3589x_gpio->regs[REG_IS][regoffset] |= mask;
177 	else
178 		tc3589x_gpio->regs[REG_IS][regoffset] &= ~mask;
179 
180 	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
181 		tc3589x_gpio->regs[REG_IEV][regoffset] |= mask;
182 	else
183 		tc3589x_gpio->regs[REG_IEV][regoffset] &= ~mask;
184 
185 	return 0;
186 }
187 
188 static void tc3589x_gpio_irq_lock(struct irq_data *d)
189 {
190 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
191 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
192 
193 	mutex_lock(&tc3589x_gpio->irq_lock);
194 }
195 
196 static void tc3589x_gpio_irq_sync_unlock(struct irq_data *d)
197 {
198 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
199 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
200 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
201 	static const u8 regmap[] = {
202 		[REG_IBE]	= TC3589x_GPIOIBE0,
203 		[REG_IEV]	= TC3589x_GPIOIEV0,
204 		[REG_IS]	= TC3589x_GPIOIS0,
205 		[REG_IE]	= TC3589x_GPIOIE0,
206 		[REG_DIRECT]	= TC3589x_DIRECT0,
207 	};
208 	int i, j;
209 
210 	for (i = 0; i < CACHE_NR_REGS; i++) {
211 		for (j = 0; j < CACHE_NR_BANKS; j++) {
212 			u8 old = tc3589x_gpio->oldregs[i][j];
213 			u8 new = tc3589x_gpio->regs[i][j];
214 
215 			if (new == old)
216 				continue;
217 
218 			tc3589x_gpio->oldregs[i][j] = new;
219 			tc3589x_reg_write(tc3589x, regmap[i] + j, new);
220 		}
221 	}
222 
223 	mutex_unlock(&tc3589x_gpio->irq_lock);
224 }
225 
226 static void tc3589x_gpio_irq_mask(struct irq_data *d)
227 {
228 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
229 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
230 	int offset = d->hwirq;
231 	int regoffset = offset / 8;
232 	int mask = BIT(offset % 8);
233 
234 	tc3589x_gpio->regs[REG_IE][regoffset] &= ~mask;
235 	tc3589x_gpio->regs[REG_DIRECT][regoffset] |= mask;
236 	gpiochip_disable_irq(gc, offset);
237 }
238 
239 static void tc3589x_gpio_irq_unmask(struct irq_data *d)
240 {
241 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
242 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
243 	int offset = d->hwirq;
244 	int regoffset = offset / 8;
245 	int mask = BIT(offset % 8);
246 
247 	gpiochip_enable_irq(gc, offset);
248 	tc3589x_gpio->regs[REG_IE][regoffset] |= mask;
249 	tc3589x_gpio->regs[REG_DIRECT][regoffset] &= ~mask;
250 }
251 
252 static const struct irq_chip tc3589x_gpio_irq_chip = {
253 	.name			= "tc3589x-gpio",
254 	.irq_bus_lock		= tc3589x_gpio_irq_lock,
255 	.irq_bus_sync_unlock	= tc3589x_gpio_irq_sync_unlock,
256 	.irq_mask		= tc3589x_gpio_irq_mask,
257 	.irq_unmask		= tc3589x_gpio_irq_unmask,
258 	.irq_set_type		= tc3589x_gpio_irq_set_type,
259 	.flags =		IRQCHIP_IMMUTABLE,
260 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
261 };
262 
263 static irqreturn_t tc3589x_gpio_irq(int irq, void *dev)
264 {
265 	struct tc3589x_gpio *tc3589x_gpio = dev;
266 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
267 	u8 status[CACHE_NR_BANKS];
268 	int ret;
269 	int i;
270 
271 	ret = tc3589x_block_read(tc3589x, TC3589x_GPIOMIS0,
272 				 ARRAY_SIZE(status), status);
273 	if (ret < 0)
274 		return IRQ_NONE;
275 
276 	for (i = 0; i < ARRAY_SIZE(status); i++) {
277 		unsigned int stat = status[i];
278 		if (!stat)
279 			continue;
280 
281 		while (stat) {
282 			int bit = __ffs(stat);
283 			int line = i * 8 + bit;
284 			int irq = irq_find_mapping(tc3589x_gpio->chip.irq.domain,
285 						   line);
286 
287 			handle_nested_irq(irq);
288 			stat &= ~(1 << bit);
289 		}
290 
291 		tc3589x_reg_write(tc3589x, TC3589x_GPIOIC0 + i, status[i]);
292 	}
293 
294 	return IRQ_HANDLED;
295 }
296 
297 static int tc3589x_gpio_probe(struct platform_device *pdev)
298 {
299 	struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
300 	struct device_node *np = pdev->dev.of_node;
301 	struct tc3589x_gpio *tc3589x_gpio;
302 	struct gpio_irq_chip *girq;
303 	int ret;
304 	int irq;
305 
306 	if (!np) {
307 		dev_err(&pdev->dev, "No Device Tree node found\n");
308 		return -EINVAL;
309 	}
310 
311 	irq = platform_get_irq(pdev, 0);
312 	if (irq < 0)
313 		return irq;
314 
315 	tc3589x_gpio = devm_kzalloc(&pdev->dev, sizeof(struct tc3589x_gpio),
316 				    GFP_KERNEL);
317 	if (!tc3589x_gpio)
318 		return -ENOMEM;
319 
320 	mutex_init(&tc3589x_gpio->irq_lock);
321 
322 	tc3589x_gpio->dev = &pdev->dev;
323 	tc3589x_gpio->tc3589x = tc3589x;
324 
325 	tc3589x_gpio->chip = template_chip;
326 	tc3589x_gpio->chip.ngpio = tc3589x->num_gpio;
327 	tc3589x_gpio->chip.parent = &pdev->dev;
328 	tc3589x_gpio->chip.base = -1;
329 
330 	girq = &tc3589x_gpio->chip.irq;
331 	gpio_irq_chip_set_chip(girq, &tc3589x_gpio_irq_chip);
332 	/* This will let us handle the parent IRQ in the driver */
333 	girq->parent_handler = NULL;
334 	girq->num_parents = 0;
335 	girq->parents = NULL;
336 	girq->default_type = IRQ_TYPE_NONE;
337 	girq->handler = handle_simple_irq;
338 	girq->threaded = true;
339 
340 	/* Bring the GPIO module out of reset */
341 	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL,
342 			       TC3589x_RSTCTRL_GPIRST, 0);
343 	if (ret < 0)
344 		return ret;
345 
346 	 /* For tc35894, have to disable Direct KBD interrupts,
347 	  * else IRQST will always be 0x20, IRQN low level, can't
348 	  * clear the irq status.
349 	  * TODO: need more test on other tc3589x chip.
350 	  *
351 	  */
352 	ret = tc3589x_reg_write(tc3589x, TC3589x_DKBDMSK,
353 			TC3589x_DKBDMSK_ELINT | TC3589x_DKBDMSK_EINT);
354 	if (ret < 0)
355 		return ret;
356 
357 	ret = devm_request_threaded_irq(&pdev->dev,
358 					irq, NULL, tc3589x_gpio_irq,
359 					IRQF_ONESHOT, "tc3589x-gpio",
360 					tc3589x_gpio);
361 	if (ret) {
362 		dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
363 		return ret;
364 	}
365 
366 	return devm_gpiochip_add_data(&pdev->dev, &tc3589x_gpio->chip, tc3589x_gpio);
367 }
368 
369 static struct platform_driver tc3589x_gpio_driver = {
370 	.driver.name	= "tc3589x-gpio",
371 	.probe		= tc3589x_gpio_probe,
372 };
373 
374 static int __init tc3589x_gpio_init(void)
375 {
376 	return platform_driver_register(&tc3589x_gpio_driver);
377 }
378 subsys_initcall(tc3589x_gpio_init);
379