1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * MAXIM MAX77620 GPIO driver
4 *
5 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
6 */
7
8 #include <linux/gpio/driver.h>
9 #include <linux/interrupt.h>
10 #include <linux/mfd/max77620.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14
15 #define GPIO_REG_ADDR(offset) (MAX77620_REG_GPIO0 + offset)
16
17 struct max77620_gpio {
18 struct gpio_chip gpio_chip;
19 struct regmap *rmap;
20 struct device *dev;
21 struct mutex buslock; /* irq_bus_lock */
22 unsigned int irq_type[MAX77620_GPIO_NR];
23 bool irq_enabled[MAX77620_GPIO_NR];
24 };
25
max77620_gpio_irqhandler(int irq,void * data)26 static irqreturn_t max77620_gpio_irqhandler(int irq, void *data)
27 {
28 struct max77620_gpio *gpio = data;
29 unsigned int value, offset;
30 unsigned long pending;
31 int err;
32
33 err = regmap_read(gpio->rmap, MAX77620_REG_IRQ_LVL2_GPIO, &value);
34 if (err < 0) {
35 dev_err(gpio->dev, "REG_IRQ_LVL2_GPIO read failed: %d\n", err);
36 return IRQ_NONE;
37 }
38
39 pending = value;
40
41 for_each_set_bit(offset, &pending, MAX77620_GPIO_NR) {
42 unsigned int virq;
43
44 virq = irq_find_mapping(gpio->gpio_chip.irq.domain, offset);
45 handle_nested_irq(virq);
46 }
47
48 return IRQ_HANDLED;
49 }
50
max77620_gpio_irq_mask(struct irq_data * data)51 static void max77620_gpio_irq_mask(struct irq_data *data)
52 {
53 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
54 struct max77620_gpio *gpio = gpiochip_get_data(chip);
55
56 gpio->irq_enabled[data->hwirq] = false;
57 }
58
max77620_gpio_irq_unmask(struct irq_data * data)59 static void max77620_gpio_irq_unmask(struct irq_data *data)
60 {
61 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
62 struct max77620_gpio *gpio = gpiochip_get_data(chip);
63
64 gpio->irq_enabled[data->hwirq] = true;
65 }
66
max77620_gpio_set_irq_type(struct irq_data * data,unsigned int type)67 static int max77620_gpio_set_irq_type(struct irq_data *data, unsigned int type)
68 {
69 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
70 struct max77620_gpio *gpio = gpiochip_get_data(chip);
71 unsigned int irq_type;
72
73 switch (type) {
74 case IRQ_TYPE_EDGE_RISING:
75 irq_type = MAX77620_CNFG_GPIO_INT_RISING;
76 break;
77
78 case IRQ_TYPE_EDGE_FALLING:
79 irq_type = MAX77620_CNFG_GPIO_INT_FALLING;
80 break;
81
82 case IRQ_TYPE_EDGE_BOTH:
83 irq_type = MAX77620_CNFG_GPIO_INT_RISING |
84 MAX77620_CNFG_GPIO_INT_FALLING;
85 break;
86
87 default:
88 return -EINVAL;
89 }
90
91 gpio->irq_type[data->hwirq] = irq_type;
92
93 return 0;
94 }
95
max77620_gpio_bus_lock(struct irq_data * data)96 static void max77620_gpio_bus_lock(struct irq_data *data)
97 {
98 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
99 struct max77620_gpio *gpio = gpiochip_get_data(chip);
100
101 mutex_lock(&gpio->buslock);
102 }
103
max77620_gpio_bus_sync_unlock(struct irq_data * data)104 static void max77620_gpio_bus_sync_unlock(struct irq_data *data)
105 {
106 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
107 struct max77620_gpio *gpio = gpiochip_get_data(chip);
108 unsigned int value, offset = data->hwirq;
109 int err;
110
111 value = gpio->irq_enabled[offset] ? gpio->irq_type[offset] : 0;
112
113 err = regmap_update_bits(gpio->rmap, GPIO_REG_ADDR(offset),
114 MAX77620_CNFG_GPIO_INT_MASK, value);
115 if (err < 0)
116 dev_err(chip->parent, "failed to update interrupt mask: %d\n",
117 err);
118
119 mutex_unlock(&gpio->buslock);
120 }
121
122 static struct irq_chip max77620_gpio_irqchip = {
123 .name = "max77620-gpio",
124 .irq_mask = max77620_gpio_irq_mask,
125 .irq_unmask = max77620_gpio_irq_unmask,
126 .irq_set_type = max77620_gpio_set_irq_type,
127 .irq_bus_lock = max77620_gpio_bus_lock,
128 .irq_bus_sync_unlock = max77620_gpio_bus_sync_unlock,
129 .flags = IRQCHIP_MASK_ON_SUSPEND,
130 };
131
max77620_gpio_dir_input(struct gpio_chip * gc,unsigned int offset)132 static int max77620_gpio_dir_input(struct gpio_chip *gc, unsigned int offset)
133 {
134 struct max77620_gpio *mgpio = gpiochip_get_data(gc);
135 int ret;
136
137 ret = regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
138 MAX77620_CNFG_GPIO_DIR_MASK,
139 MAX77620_CNFG_GPIO_DIR_INPUT);
140 if (ret < 0)
141 dev_err(mgpio->dev, "CNFG_GPIOx dir update failed: %d\n", ret);
142
143 return ret;
144 }
145
max77620_gpio_get(struct gpio_chip * gc,unsigned int offset)146 static int max77620_gpio_get(struct gpio_chip *gc, unsigned int offset)
147 {
148 struct max77620_gpio *mgpio = gpiochip_get_data(gc);
149 unsigned int val;
150 int ret;
151
152 ret = regmap_read(mgpio->rmap, GPIO_REG_ADDR(offset), &val);
153 if (ret < 0) {
154 dev_err(mgpio->dev, "CNFG_GPIOx read failed: %d\n", ret);
155 return ret;
156 }
157
158 if (val & MAX77620_CNFG_GPIO_DIR_MASK)
159 return !!(val & MAX77620_CNFG_GPIO_INPUT_VAL_MASK);
160 else
161 return !!(val & MAX77620_CNFG_GPIO_OUTPUT_VAL_MASK);
162 }
163
max77620_gpio_dir_output(struct gpio_chip * gc,unsigned int offset,int value)164 static int max77620_gpio_dir_output(struct gpio_chip *gc, unsigned int offset,
165 int value)
166 {
167 struct max77620_gpio *mgpio = gpiochip_get_data(gc);
168 u8 val;
169 int ret;
170
171 val = (value) ? MAX77620_CNFG_GPIO_OUTPUT_VAL_HIGH :
172 MAX77620_CNFG_GPIO_OUTPUT_VAL_LOW;
173
174 ret = regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
175 MAX77620_CNFG_GPIO_OUTPUT_VAL_MASK, val);
176 if (ret < 0) {
177 dev_err(mgpio->dev, "CNFG_GPIOx val update failed: %d\n", ret);
178 return ret;
179 }
180
181 ret = regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
182 MAX77620_CNFG_GPIO_DIR_MASK,
183 MAX77620_CNFG_GPIO_DIR_OUTPUT);
184 if (ret < 0)
185 dev_err(mgpio->dev, "CNFG_GPIOx dir update failed: %d\n", ret);
186
187 return ret;
188 }
189
max77620_gpio_set_debounce(struct max77620_gpio * mgpio,unsigned int offset,unsigned int debounce)190 static int max77620_gpio_set_debounce(struct max77620_gpio *mgpio,
191 unsigned int offset,
192 unsigned int debounce)
193 {
194 u8 val;
195 int ret;
196
197 switch (debounce) {
198 case 0:
199 val = MAX77620_CNFG_GPIO_DBNC_None;
200 break;
201 case 1 ... 8000:
202 val = MAX77620_CNFG_GPIO_DBNC_8ms;
203 break;
204 case 8001 ... 16000:
205 val = MAX77620_CNFG_GPIO_DBNC_16ms;
206 break;
207 case 16001 ... 32000:
208 val = MAX77620_CNFG_GPIO_DBNC_32ms;
209 break;
210 default:
211 dev_err(mgpio->dev, "Illegal value %u\n", debounce);
212 return -EINVAL;
213 }
214
215 ret = regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
216 MAX77620_CNFG_GPIO_DBNC_MASK, val);
217 if (ret < 0)
218 dev_err(mgpio->dev, "CNFG_GPIOx_DBNC update failed: %d\n", ret);
219
220 return ret;
221 }
222
max77620_gpio_set(struct gpio_chip * gc,unsigned int offset,int value)223 static void max77620_gpio_set(struct gpio_chip *gc, unsigned int offset,
224 int value)
225 {
226 struct max77620_gpio *mgpio = gpiochip_get_data(gc);
227 u8 val;
228 int ret;
229
230 val = (value) ? MAX77620_CNFG_GPIO_OUTPUT_VAL_HIGH :
231 MAX77620_CNFG_GPIO_OUTPUT_VAL_LOW;
232
233 ret = regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
234 MAX77620_CNFG_GPIO_OUTPUT_VAL_MASK, val);
235 if (ret < 0)
236 dev_err(mgpio->dev, "CNFG_GPIO_OUT update failed: %d\n", ret);
237 }
238
max77620_gpio_set_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)239 static int max77620_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
240 unsigned long config)
241 {
242 struct max77620_gpio *mgpio = gpiochip_get_data(gc);
243
244 switch (pinconf_to_config_param(config)) {
245 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
246 return regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
247 MAX77620_CNFG_GPIO_DRV_MASK,
248 MAX77620_CNFG_GPIO_DRV_OPENDRAIN);
249 case PIN_CONFIG_DRIVE_PUSH_PULL:
250 return regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
251 MAX77620_CNFG_GPIO_DRV_MASK,
252 MAX77620_CNFG_GPIO_DRV_PUSHPULL);
253 case PIN_CONFIG_INPUT_DEBOUNCE:
254 return max77620_gpio_set_debounce(mgpio, offset,
255 pinconf_to_config_argument(config));
256 default:
257 break;
258 }
259
260 return -ENOTSUPP;
261 }
262
max77620_gpio_irq_init_hw(struct gpio_chip * gc)263 static int max77620_gpio_irq_init_hw(struct gpio_chip *gc)
264 {
265 struct max77620_gpio *gpio = gpiochip_get_data(gc);
266 unsigned int i;
267 int err;
268
269 /*
270 * GPIO interrupts may be left ON after bootloader, hence let's
271 * pre-initialize hardware to the expected state by disabling all
272 * the interrupts.
273 */
274 for (i = 0; i < MAX77620_GPIO_NR; i++) {
275 err = regmap_update_bits(gpio->rmap, GPIO_REG_ADDR(i),
276 MAX77620_CNFG_GPIO_INT_MASK, 0);
277 if (err < 0) {
278 dev_err(gpio->dev,
279 "failed to disable interrupt: %d\n", err);
280 return err;
281 }
282 }
283
284 return 0;
285 }
286
max77620_gpio_probe(struct platform_device * pdev)287 static int max77620_gpio_probe(struct platform_device *pdev)
288 {
289 struct max77620_chip *chip = dev_get_drvdata(pdev->dev.parent);
290 struct max77620_gpio *mgpio;
291 struct gpio_irq_chip *girq;
292 unsigned int gpio_irq;
293 int ret;
294
295 ret = platform_get_irq(pdev, 0);
296 if (ret < 0)
297 return ret;
298
299 gpio_irq = ret;
300
301 mgpio = devm_kzalloc(&pdev->dev, sizeof(*mgpio), GFP_KERNEL);
302 if (!mgpio)
303 return -ENOMEM;
304
305 mutex_init(&mgpio->buslock);
306 mgpio->rmap = chip->rmap;
307 mgpio->dev = &pdev->dev;
308
309 mgpio->gpio_chip.label = pdev->name;
310 mgpio->gpio_chip.parent = pdev->dev.parent;
311 mgpio->gpio_chip.direction_input = max77620_gpio_dir_input;
312 mgpio->gpio_chip.get = max77620_gpio_get;
313 mgpio->gpio_chip.direction_output = max77620_gpio_dir_output;
314 mgpio->gpio_chip.set = max77620_gpio_set;
315 mgpio->gpio_chip.set_config = max77620_gpio_set_config;
316 mgpio->gpio_chip.ngpio = MAX77620_GPIO_NR;
317 mgpio->gpio_chip.can_sleep = 1;
318 mgpio->gpio_chip.base = -1;
319
320 girq = &mgpio->gpio_chip.irq;
321 girq->chip = &max77620_gpio_irqchip;
322 /* This will let us handle the parent IRQ in the driver */
323 girq->parent_handler = NULL;
324 girq->num_parents = 0;
325 girq->parents = NULL;
326 girq->default_type = IRQ_TYPE_NONE;
327 girq->handler = handle_edge_irq;
328 girq->init_hw = max77620_gpio_irq_init_hw;
329 girq->threaded = true;
330
331 platform_set_drvdata(pdev, mgpio);
332
333 ret = devm_gpiochip_add_data(&pdev->dev, &mgpio->gpio_chip, mgpio);
334 if (ret < 0) {
335 dev_err(&pdev->dev, "gpio_init: Failed to add max77620_gpio\n");
336 return ret;
337 }
338
339 ret = devm_request_threaded_irq(&pdev->dev, gpio_irq, NULL,
340 max77620_gpio_irqhandler, IRQF_ONESHOT,
341 "max77620-gpio", mgpio);
342 if (ret < 0) {
343 dev_err(&pdev->dev, "failed to request IRQ: %d\n", ret);
344 return ret;
345 }
346
347 return 0;
348 }
349
350 static const struct platform_device_id max77620_gpio_devtype[] = {
351 { .name = "max77620-gpio", },
352 { .name = "max20024-gpio", },
353 {},
354 };
355 MODULE_DEVICE_TABLE(platform, max77620_gpio_devtype);
356
357 static struct platform_driver max77620_gpio_driver = {
358 .driver.name = "max77620-gpio",
359 .probe = max77620_gpio_probe,
360 .id_table = max77620_gpio_devtype,
361 };
362
363 module_platform_driver(max77620_gpio_driver);
364
365 MODULE_DESCRIPTION("GPIO interface for MAX77620 and MAX20024 PMIC");
366 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
367 MODULE_AUTHOR("Chaitanya Bandi <bandik@nvidia.com>");
368 MODULE_LICENSE("GPL v2");
369