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
tc3589x_gpio_get(struct gpio_chip * chip,unsigned int offset)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
tc3589x_gpio_set(struct gpio_chip * chip,unsigned int offset,int val)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
tc3589x_gpio_direction_output(struct gpio_chip * chip,unsigned int offset,int val)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
tc3589x_gpio_direction_input(struct gpio_chip * chip,unsigned int offset)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
tc3589x_gpio_get_direction(struct gpio_chip * chip,unsigned int offset)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
tc3589x_gpio_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)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
tc3589x_gpio_irq_set_type(struct irq_data * d,unsigned int type)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
tc3589x_gpio_irq_lock(struct irq_data * d)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
tc3589x_gpio_irq_sync_unlock(struct irq_data * d)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 [REG_DIRECT] = TC3589x_DIRECT0,
204 };
205 int i, j;
206
207 for (i = 0; i < CACHE_NR_REGS; i++) {
208 for (j = 0; j < CACHE_NR_BANKS; j++) {
209 u8 old = tc3589x_gpio->oldregs[i][j];
210 u8 new = tc3589x_gpio->regs[i][j];
211
212 if (new == old)
213 continue;
214
215 tc3589x_gpio->oldregs[i][j] = new;
216 tc3589x_reg_write(tc3589x, regmap[i] + j, new);
217 }
218 }
219
220 mutex_unlock(&tc3589x_gpio->irq_lock);
221 }
222
tc3589x_gpio_irq_mask(struct irq_data * d)223 static void tc3589x_gpio_irq_mask(struct irq_data *d)
224 {
225 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
226 struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
227 int offset = d->hwirq;
228 int regoffset = offset / 8;
229 int mask = BIT(offset % 8);
230
231 tc3589x_gpio->regs[REG_IE][regoffset] &= ~mask;
232 tc3589x_gpio->regs[REG_DIRECT][regoffset] |= mask;
233 gpiochip_disable_irq(gc, offset);
234 }
235
tc3589x_gpio_irq_unmask(struct irq_data * d)236 static void tc3589x_gpio_irq_unmask(struct irq_data *d)
237 {
238 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
239 struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
240 int offset = d->hwirq;
241 int regoffset = offset / 8;
242 int mask = BIT(offset % 8);
243
244 gpiochip_enable_irq(gc, offset);
245 tc3589x_gpio->regs[REG_IE][regoffset] |= mask;
246 tc3589x_gpio->regs[REG_DIRECT][regoffset] &= ~mask;
247 }
248
249 static const struct irq_chip tc3589x_gpio_irq_chip = {
250 .name = "tc3589x-gpio",
251 .irq_bus_lock = tc3589x_gpio_irq_lock,
252 .irq_bus_sync_unlock = tc3589x_gpio_irq_sync_unlock,
253 .irq_mask = tc3589x_gpio_irq_mask,
254 .irq_unmask = tc3589x_gpio_irq_unmask,
255 .irq_set_type = tc3589x_gpio_irq_set_type,
256 .flags = IRQCHIP_IMMUTABLE,
257 GPIOCHIP_IRQ_RESOURCE_HELPERS,
258 };
259
tc3589x_gpio_irq(int irq,void * dev)260 static irqreturn_t tc3589x_gpio_irq(int irq, void *dev)
261 {
262 struct tc3589x_gpio *tc3589x_gpio = dev;
263 struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
264 u8 status[CACHE_NR_BANKS];
265 int ret;
266 int i;
267
268 ret = tc3589x_block_read(tc3589x, TC3589x_GPIOMIS0,
269 ARRAY_SIZE(status), status);
270 if (ret < 0)
271 return IRQ_NONE;
272
273 for (i = 0; i < ARRAY_SIZE(status); i++) {
274 unsigned int stat = status[i];
275 if (!stat)
276 continue;
277
278 while (stat) {
279 int bit = __ffs(stat);
280 int line = i * 8 + bit;
281 int irq = irq_find_mapping(tc3589x_gpio->chip.irq.domain,
282 line);
283
284 handle_nested_irq(irq);
285 stat &= ~(1 << bit);
286 }
287
288 tc3589x_reg_write(tc3589x, TC3589x_GPIOIC0 + i, status[i]);
289 }
290
291 return IRQ_HANDLED;
292 }
293
tc3589x_gpio_probe(struct platform_device * pdev)294 static int tc3589x_gpio_probe(struct platform_device *pdev)
295 {
296 struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
297 struct device_node *np = pdev->dev.of_node;
298 struct tc3589x_gpio *tc3589x_gpio;
299 struct gpio_irq_chip *girq;
300 int ret;
301 int irq;
302
303 if (!np) {
304 dev_err(&pdev->dev, "No Device Tree node found\n");
305 return -EINVAL;
306 }
307
308 irq = platform_get_irq(pdev, 0);
309 if (irq < 0)
310 return irq;
311
312 tc3589x_gpio = devm_kzalloc(&pdev->dev, sizeof(struct tc3589x_gpio),
313 GFP_KERNEL);
314 if (!tc3589x_gpio)
315 return -ENOMEM;
316
317 mutex_init(&tc3589x_gpio->irq_lock);
318
319 tc3589x_gpio->dev = &pdev->dev;
320 tc3589x_gpio->tc3589x = tc3589x;
321
322 tc3589x_gpio->chip = template_chip;
323 tc3589x_gpio->chip.ngpio = tc3589x->num_gpio;
324 tc3589x_gpio->chip.parent = &pdev->dev;
325 tc3589x_gpio->chip.base = -1;
326
327 girq = &tc3589x_gpio->chip.irq;
328 gpio_irq_chip_set_chip(girq, &tc3589x_gpio_irq_chip);
329 /* This will let us handle the parent IRQ in the driver */
330 girq->parent_handler = NULL;
331 girq->num_parents = 0;
332 girq->parents = NULL;
333 girq->default_type = IRQ_TYPE_NONE;
334 girq->handler = handle_simple_irq;
335 girq->threaded = true;
336
337 /* Bring the GPIO module out of reset */
338 ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL,
339 TC3589x_RSTCTRL_GPIRST, 0);
340 if (ret < 0)
341 return ret;
342
343 /* For tc35894, have to disable Direct KBD interrupts,
344 * else IRQST will always be 0x20, IRQN low level, can't
345 * clear the irq status.
346 * TODO: need more test on other tc3589x chip.
347 *
348 */
349 ret = tc3589x_reg_write(tc3589x, TC3589x_DKBDMSK,
350 TC3589x_DKBDMSK_ELINT | TC3589x_DKBDMSK_EINT);
351 if (ret < 0)
352 return ret;
353
354 ret = devm_request_threaded_irq(&pdev->dev,
355 irq, NULL, tc3589x_gpio_irq,
356 IRQF_ONESHOT, "tc3589x-gpio",
357 tc3589x_gpio);
358 if (ret) {
359 dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
360 return ret;
361 }
362
363 return devm_gpiochip_add_data(&pdev->dev, &tc3589x_gpio->chip, tc3589x_gpio);
364 }
365
366 static struct platform_driver tc3589x_gpio_driver = {
367 .driver.name = "tc3589x-gpio",
368 .probe = tc3589x_gpio_probe,
369 };
370
tc3589x_gpio_init(void)371 static int __init tc3589x_gpio_init(void)
372 {
373 return platform_driver_register(&tc3589x_gpio_driver);
374 }
375 subsys_initcall(tc3589x_gpio_init);
376