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