xref: /openbmc/linux/drivers/gpio/gpio-tc3589x.c (revision 62975d27)
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 };
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 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 void 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 	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 
71 	tc3589x_gpio_set(chip, offset, val);
72 
73 	return tc3589x_set_bits(tc3589x, reg, BIT(pos), BIT(pos));
74 }
75 
76 static int tc3589x_gpio_direction_input(struct gpio_chip *chip,
77 					unsigned int offset)
78 {
79 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
80 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
81 	u8 reg = TC3589x_GPIODIR0 + offset / 8;
82 	unsigned int pos = offset % 8;
83 
84 	return tc3589x_set_bits(tc3589x, reg, BIT(pos), 0);
85 }
86 
87 static int tc3589x_gpio_get_direction(struct gpio_chip *chip,
88 				      unsigned int offset)
89 {
90 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
91 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
92 	u8 reg = TC3589x_GPIODIR0 + offset / 8;
93 	unsigned int pos = offset % 8;
94 	int ret;
95 
96 	ret = tc3589x_reg_read(tc3589x, reg);
97 	if (ret < 0)
98 		return ret;
99 
100 	if (ret & BIT(pos))
101 		return GPIO_LINE_DIRECTION_OUT;
102 
103 	return GPIO_LINE_DIRECTION_IN;
104 }
105 
106 static int tc3589x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
107 				   unsigned long config)
108 {
109 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
110 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
111 	/*
112 	 * These registers are alterated at each second address
113 	 * ODM bit 0 = drive to GND or Hi-Z (open drain)
114 	 * ODM bit 1 = drive to VDD or Hi-Z (open source)
115 	 */
116 	u8 odmreg = TC3589x_GPIOODM0 + (offset / 8) * 2;
117 	u8 odereg = TC3589x_GPIOODE0 + (offset / 8) * 2;
118 	unsigned int pos = offset % 8;
119 	int ret;
120 
121 	switch (pinconf_to_config_param(config)) {
122 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
123 		/* Set open drain mode */
124 		ret = tc3589x_set_bits(tc3589x, odmreg, BIT(pos), 0);
125 		if (ret)
126 			return ret;
127 		/* Enable open drain/source mode */
128 		return tc3589x_set_bits(tc3589x, odereg, BIT(pos), BIT(pos));
129 	case PIN_CONFIG_DRIVE_OPEN_SOURCE:
130 		/* Set open source mode */
131 		ret = tc3589x_set_bits(tc3589x, odmreg, BIT(pos), BIT(pos));
132 		if (ret)
133 			return ret;
134 		/* Enable open drain/source mode */
135 		return tc3589x_set_bits(tc3589x, odereg, BIT(pos), BIT(pos));
136 	case PIN_CONFIG_DRIVE_PUSH_PULL:
137 		/* Disable open drain/source mode */
138 		return tc3589x_set_bits(tc3589x, odereg, BIT(pos), 0);
139 	default:
140 		break;
141 	}
142 	return -ENOTSUPP;
143 }
144 
145 static const struct gpio_chip template_chip = {
146 	.label			= "tc3589x",
147 	.owner			= THIS_MODULE,
148 	.get			= tc3589x_gpio_get,
149 	.set			= tc3589x_gpio_set,
150 	.direction_output	= tc3589x_gpio_direction_output,
151 	.direction_input	= tc3589x_gpio_direction_input,
152 	.get_direction		= tc3589x_gpio_get_direction,
153 	.set_config		= tc3589x_gpio_set_config,
154 	.can_sleep		= true,
155 };
156 
157 static int tc3589x_gpio_irq_set_type(struct irq_data *d, unsigned int type)
158 {
159 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
160 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
161 	int offset = d->hwirq;
162 	int regoffset = offset / 8;
163 	int mask = BIT(offset % 8);
164 
165 	if (type == IRQ_TYPE_EDGE_BOTH) {
166 		tc3589x_gpio->regs[REG_IBE][regoffset] |= mask;
167 		return 0;
168 	}
169 
170 	tc3589x_gpio->regs[REG_IBE][regoffset] &= ~mask;
171 
172 	if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
173 		tc3589x_gpio->regs[REG_IS][regoffset] |= mask;
174 	else
175 		tc3589x_gpio->regs[REG_IS][regoffset] &= ~mask;
176 
177 	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
178 		tc3589x_gpio->regs[REG_IEV][regoffset] |= mask;
179 	else
180 		tc3589x_gpio->regs[REG_IEV][regoffset] &= ~mask;
181 
182 	return 0;
183 }
184 
185 static void tc3589x_gpio_irq_lock(struct irq_data *d)
186 {
187 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
188 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
189 
190 	mutex_lock(&tc3589x_gpio->irq_lock);
191 }
192 
193 static void tc3589x_gpio_irq_sync_unlock(struct irq_data *d)
194 {
195 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
196 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
197 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
198 	static const u8 regmap[] = {
199 		[REG_IBE]	= TC3589x_GPIOIBE0,
200 		[REG_IEV]	= TC3589x_GPIOIEV0,
201 		[REG_IS]	= TC3589x_GPIOIS0,
202 		[REG_IE]	= TC3589x_GPIOIE0,
203 	};
204 	int i, j;
205 
206 	for (i = 0; i < CACHE_NR_REGS; i++) {
207 		for (j = 0; j < CACHE_NR_BANKS; j++) {
208 			u8 old = tc3589x_gpio->oldregs[i][j];
209 			u8 new = tc3589x_gpio->regs[i][j];
210 
211 			if (new == old)
212 				continue;
213 
214 			tc3589x_gpio->oldregs[i][j] = new;
215 			tc3589x_reg_write(tc3589x, regmap[i] + j * 8, new);
216 		}
217 	}
218 
219 	mutex_unlock(&tc3589x_gpio->irq_lock);
220 }
221 
222 static void tc3589x_gpio_irq_mask(struct irq_data *d)
223 {
224 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
225 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
226 	int offset = d->hwirq;
227 	int regoffset = offset / 8;
228 	int mask = BIT(offset % 8);
229 
230 	tc3589x_gpio->regs[REG_IE][regoffset] &= ~mask;
231 }
232 
233 static void tc3589x_gpio_irq_unmask(struct irq_data *d)
234 {
235 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
236 	struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
237 	int offset = d->hwirq;
238 	int regoffset = offset / 8;
239 	int mask = BIT(offset % 8);
240 
241 	tc3589x_gpio->regs[REG_IE][regoffset] |= mask;
242 }
243 
244 static struct irq_chip tc3589x_gpio_irq_chip = {
245 	.name			= "tc3589x-gpio",
246 	.irq_bus_lock		= tc3589x_gpio_irq_lock,
247 	.irq_bus_sync_unlock	= tc3589x_gpio_irq_sync_unlock,
248 	.irq_mask		= tc3589x_gpio_irq_mask,
249 	.irq_unmask		= tc3589x_gpio_irq_unmask,
250 	.irq_set_type		= tc3589x_gpio_irq_set_type,
251 };
252 
253 static irqreturn_t tc3589x_gpio_irq(int irq, void *dev)
254 {
255 	struct tc3589x_gpio *tc3589x_gpio = dev;
256 	struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
257 	u8 status[CACHE_NR_BANKS];
258 	int ret;
259 	int i;
260 
261 	ret = tc3589x_block_read(tc3589x, TC3589x_GPIOMIS0,
262 				 ARRAY_SIZE(status), status);
263 	if (ret < 0)
264 		return IRQ_NONE;
265 
266 	for (i = 0; i < ARRAY_SIZE(status); i++) {
267 		unsigned int stat = status[i];
268 		if (!stat)
269 			continue;
270 
271 		while (stat) {
272 			int bit = __ffs(stat);
273 			int line = i * 8 + bit;
274 			int irq = irq_find_mapping(tc3589x_gpio->chip.irq.domain,
275 						   line);
276 
277 			handle_nested_irq(irq);
278 			stat &= ~(1 << bit);
279 		}
280 
281 		tc3589x_reg_write(tc3589x, TC3589x_GPIOIC0 + i, status[i]);
282 	}
283 
284 	return IRQ_HANDLED;
285 }
286 
287 static int tc3589x_gpio_probe(struct platform_device *pdev)
288 {
289 	struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
290 	struct device_node *np = pdev->dev.of_node;
291 	struct tc3589x_gpio *tc3589x_gpio;
292 	int ret;
293 	int irq;
294 
295 	if (!np) {
296 		dev_err(&pdev->dev, "No Device Tree node found\n");
297 		return -EINVAL;
298 	}
299 
300 	irq = platform_get_irq(pdev, 0);
301 	if (irq < 0)
302 		return irq;
303 
304 	tc3589x_gpio = devm_kzalloc(&pdev->dev, sizeof(struct tc3589x_gpio),
305 				    GFP_KERNEL);
306 	if (!tc3589x_gpio)
307 		return -ENOMEM;
308 
309 	mutex_init(&tc3589x_gpio->irq_lock);
310 
311 	tc3589x_gpio->dev = &pdev->dev;
312 	tc3589x_gpio->tc3589x = tc3589x;
313 
314 	tc3589x_gpio->chip = template_chip;
315 	tc3589x_gpio->chip.ngpio = tc3589x->num_gpio;
316 	tc3589x_gpio->chip.parent = &pdev->dev;
317 	tc3589x_gpio->chip.base = -1;
318 	tc3589x_gpio->chip.of_node = np;
319 
320 	/* Bring the GPIO module out of reset */
321 	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL,
322 			       TC3589x_RSTCTRL_GPIRST, 0);
323 	if (ret < 0)
324 		return ret;
325 
326 	ret = devm_request_threaded_irq(&pdev->dev,
327 					irq, NULL, tc3589x_gpio_irq,
328 					IRQF_ONESHOT, "tc3589x-gpio",
329 					tc3589x_gpio);
330 	if (ret) {
331 		dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
332 		return ret;
333 	}
334 
335 	ret = devm_gpiochip_add_data(&pdev->dev, &tc3589x_gpio->chip,
336 				     tc3589x_gpio);
337 	if (ret) {
338 		dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
339 		return ret;
340 	}
341 
342 	ret =  gpiochip_irqchip_add_nested(&tc3589x_gpio->chip,
343 					   &tc3589x_gpio_irq_chip,
344 					   0,
345 					   handle_simple_irq,
346 					   IRQ_TYPE_NONE);
347 	if (ret) {
348 		dev_err(&pdev->dev,
349 			"could not connect irqchip to gpiochip\n");
350 		return ret;
351 	}
352 
353 	gpiochip_set_nested_irqchip(&tc3589x_gpio->chip,
354 				    &tc3589x_gpio_irq_chip,
355 				    irq);
356 
357 	platform_set_drvdata(pdev, tc3589x_gpio);
358 
359 	return 0;
360 }
361 
362 static struct platform_driver tc3589x_gpio_driver = {
363 	.driver.name	= "tc3589x-gpio",
364 	.probe		= tc3589x_gpio_probe,
365 };
366 
367 static int __init tc3589x_gpio_init(void)
368 {
369 	return platform_driver_register(&tc3589x_gpio_driver);
370 }
371 subsys_initcall(tc3589x_gpio_init);
372