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  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
 17struct 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
 26static 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
 51static 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
 59static 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
 67static 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
 96static 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
104static 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
122static 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
132static 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
146static 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
164static 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
190static 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
223static 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
239static 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
263static 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
287static 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
350static const struct platform_device_id max77620_gpio_devtype[] = {
351	{ .name = "max77620-gpio", },
352	{ .name = "max20024-gpio", },
353	{},
354};
355MODULE_DEVICE_TABLE(platform, max77620_gpio_devtype);
356
357static struct platform_driver max77620_gpio_driver = {
358	.driver.name	= "max77620-gpio",
359	.probe		= max77620_gpio_probe,
360	.id_table	= max77620_gpio_devtype,
361};
362
363module_platform_driver(max77620_gpio_driver);
364
365MODULE_DESCRIPTION("GPIO interface for MAX77620 and MAX20024 PMIC");
366MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
367MODULE_AUTHOR("Chaitanya Bandi <bandik@nvidia.com>");
368MODULE_ALIAS("platform:max77620-gpio");
369MODULE_LICENSE("GPL v2");