gpio-wm831x.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * gpiolib support for Wolfson WM831x PMICs
  4 *
  5 * Copyright 2009 Wolfson Microelectronics PLC.
  6 *
  7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
  8 *
  9 */
 10
 11#include <linux/cleanup.h>
 12#include <linux/kernel.h>
 13#include <linux/slab.h>
 14#include <linux/module.h>
 15#include <linux/gpio/driver.h>
 16#include <linux/mfd/core.h>
 17#include <linux/platform_device.h>
 18#include <linux/seq_file.h>
 19#include <linux/string_choices.h>
 20
 21#include <linux/mfd/wm831x/core.h>
 22#include <linux/mfd/wm831x/pdata.h>
 23#include <linux/mfd/wm831x/gpio.h>
 24#include <linux/mfd/wm831x/irq.h>
 25
 26struct wm831x_gpio {
 27	struct wm831x *wm831x;
 28	struct gpio_chip gpio_chip;
 29};
 30
 31static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
 32{
 33	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
 34	struct wm831x *wm831x = wm831x_gpio->wm831x;
 35	int val = WM831X_GPN_DIR;
 36
 37	if (wm831x->has_gpio_ena)
 38		val |= WM831X_GPN_TRI;
 39
 40	return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
 41			       WM831X_GPN_DIR | WM831X_GPN_TRI |
 42			       WM831X_GPN_FN_MASK, val);
 43}
 44
 45static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
 46{
 47	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
 48	struct wm831x *wm831x = wm831x_gpio->wm831x;
 49	int ret;
 50
 51	ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
 52	if (ret < 0)
 53		return ret;
 54
 55	if (ret & 1 << offset)
 56		return 1;
 57	else
 58		return 0;
 59}
 60
 61static int wm831x_gpio_set(struct gpio_chip *chip, unsigned int offset,
 62			   int value)
 63{
 64	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
 65	struct wm831x *wm831x = wm831x_gpio->wm831x;
 66
 67	return wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
 68			       value << offset);
 69}
 70
 71static int wm831x_gpio_direction_out(struct gpio_chip *chip,
 72				     unsigned offset, int value)
 73{
 74	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
 75	struct wm831x *wm831x = wm831x_gpio->wm831x;
 76	int val = 0;
 77	int ret;
 78
 79	if (wm831x->has_gpio_ena)
 80		val |= WM831X_GPN_TRI;
 81
 82	ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
 83			      WM831X_GPN_DIR | WM831X_GPN_TRI |
 84			      WM831X_GPN_FN_MASK, val);
 85	if (ret < 0)
 86		return ret;
 87
 88	/* Can only set GPIO state once it's in output mode */
 89	return wm831x_gpio_set(chip, offset, value);
 90}
 91
 92static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 93{
 94	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
 95	struct wm831x *wm831x = wm831x_gpio->wm831x;
 96
 97	return irq_create_mapping(wm831x->irq_domain,
 98				  WM831X_IRQ_GPIO_1 + offset);
 99}
100
101static int wm831x_gpio_set_debounce(struct wm831x *wm831x, unsigned offset,
102				    unsigned debounce)
103{
104	int reg = WM831X_GPIO1_CONTROL + offset;
105	int ret, fn;
106
107	ret = wm831x_reg_read(wm831x, reg);
108	if (ret < 0)
109		return ret;
110
111	switch (ret & WM831X_GPN_FN_MASK) {
112	case 0:
113	case 1:
114		break;
115	default:
116		/* Not in GPIO mode */
117		return -EBUSY;
118	}
119
120	if (debounce >= 32 && debounce <= 64)
121		fn = 0;
122	else if (debounce >= 4000 && debounce <= 8000)
123		fn = 1;
124	else
125		return -EINVAL;
126
127	return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
128}
129
130static int wm831x_set_config(struct gpio_chip *chip, unsigned int offset,
131			     unsigned long config)
132{
133	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
134	struct wm831x *wm831x = wm831x_gpio->wm831x;
135	int reg = WM831X_GPIO1_CONTROL + offset;
136
137	switch (pinconf_to_config_param(config)) {
138	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
139		return wm831x_set_bits(wm831x, reg,
140				       WM831X_GPN_OD_MASK, WM831X_GPN_OD);
141	case PIN_CONFIG_DRIVE_PUSH_PULL:
142		return wm831x_set_bits(wm831x, reg,
143				       WM831X_GPN_OD_MASK, 0);
144	case PIN_CONFIG_INPUT_DEBOUNCE:
145		return wm831x_gpio_set_debounce(wm831x, offset,
146			pinconf_to_config_argument(config));
147	default:
148		break;
149	}
150
151	return -ENOTSUPP;
152}
153
154#ifdef CONFIG_DEBUG_FS
155static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
156{
157	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
158	struct wm831x *wm831x = wm831x_gpio->wm831x;
159	int i, tristated;
160
161	for (i = 0; i < chip->ngpio; i++) {
162		int reg;
163		const char *pull, *powerdomain;
164
165		/* We report the GPIO even if it's not requested since
166		 * we're also reporting things like alternate
167		 * functions which apply even when the GPIO is not in
168		 * use as a GPIO.
169		 */
170		char *label __free(kfree) = gpiochip_dup_line_label(chip, i);
171		if (IS_ERR(label)) {
172			dev_err(wm831x->dev, "Failed to duplicate label\n");
173			continue;
174		}
175
176		seq_printf(s, " gpio-%-3d (%-20.20s) ",
177			   i, label ?: "Unrequested");
178
179		reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
180		if (reg < 0) {
181			dev_err(wm831x->dev,
182				"GPIO control %d read failed: %d\n",
183				i, reg);
184			seq_putc(s, '\n');
185			continue;
186		}
187
188		switch (reg & WM831X_GPN_PULL_MASK) {
189		case WM831X_GPIO_PULL_NONE:
190			pull = "nopull";
191			break;
192		case WM831X_GPIO_PULL_DOWN:
193			pull = "pulldown";
194			break;
195		case WM831X_GPIO_PULL_UP:
196			pull = "pullup";
197			break;
198		default:
199			pull = "INVALID PULL";
200			break;
201		}
202
203		switch (i + 1) {
204		case 1 ... 3:
205		case 7 ... 9:
206			if (reg & WM831X_GPN_PWR_DOM)
207				powerdomain = "VPMIC";
208			else
209				powerdomain = "DBVDD";
210			break;
211
212		case 4 ... 6:
213		case 10 ... 12:
214			if (reg & WM831X_GPN_PWR_DOM)
215				powerdomain = "SYSVDD";
216			else
217				powerdomain = "DBVDD";
218			break;
219
220		case 13 ... 16:
221			powerdomain = "TPVDD";
222			break;
223
224		default:
225			BUG();
226			break;
227		}
228
229		tristated = reg & WM831X_GPN_TRI;
230		if (wm831x->has_gpio_ena)
231			tristated = !tristated;
232
233		seq_printf(s, " %s %s %s %s%s\n"
234			   "                                  %s%s (0x%4x)\n",
235			   reg & WM831X_GPN_DIR ? "in" : "out",
236			   str_high_low(wm831x_gpio_get(chip, i)),
237			   pull,
238			   powerdomain,
239			   reg & WM831X_GPN_POL ? "" : " inverted",
240			   reg & WM831X_GPN_OD ? "open-drain" : "push-pull",
241			   tristated ? " tristated" : "",
242			   reg);
243	}
244}
245#else
246#define wm831x_gpio_dbg_show NULL
247#endif
248
249static const struct gpio_chip template_chip = {
250	.label			= "wm831x",
251	.owner			= THIS_MODULE,
252	.direction_input	= wm831x_gpio_direction_in,
253	.get			= wm831x_gpio_get,
254	.direction_output	= wm831x_gpio_direction_out,
255	.set			= wm831x_gpio_set,
256	.to_irq			= wm831x_gpio_to_irq,
257	.set_config		= wm831x_set_config,
258	.dbg_show		= wm831x_gpio_dbg_show,
259	.can_sleep		= true,
260};
261
262static int wm831x_gpio_probe(struct platform_device *pdev)
263{
264	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
265	struct wm831x_pdata *pdata = &wm831x->pdata;
266	struct wm831x_gpio *wm831x_gpio;
267
268	device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));
269
270	wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
271				   GFP_KERNEL);
272	if (wm831x_gpio == NULL)
273		return -ENOMEM;
274
275	wm831x_gpio->wm831x = wm831x;
276	wm831x_gpio->gpio_chip = template_chip;
277	wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
278	wm831x_gpio->gpio_chip.parent = &pdev->dev;
279	if (pdata && pdata->gpio_base)
280		wm831x_gpio->gpio_chip.base = pdata->gpio_base;
281	else
282		wm831x_gpio->gpio_chip.base = -1;
283
284	return devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip, wm831x_gpio);
285}
286
287static struct platform_driver wm831x_gpio_driver = {
288	.driver.name	= "wm831x-gpio",
289	.probe		= wm831x_gpio_probe,
290};
291
292static int __init wm831x_gpio_init(void)
293{
294	return platform_driver_register(&wm831x_gpio_driver);
295}
296subsys_initcall(wm831x_gpio_init);
297
298static void __exit wm831x_gpio_exit(void)
299{
300	platform_driver_unregister(&wm831x_gpio_driver);
301}
302module_exit(wm831x_gpio_exit);
303
304MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
305MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
306MODULE_LICENSE("GPL");
307MODULE_ALIAS("platform:wm831x-gpio");