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gpio-wm831x.c
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1 /*
2  * gpiolib support for Wolfson WM831x PMICs
3  *
4  * Copyright 2009 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <[email protected]>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the
10  * Free Software Foundation; either version 2 of the License, or (at your
11  * option) any later version.
12  *
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 #include <linux/gpio.h>
19 #include <linux/mfd/core.h>
20 #include <linux/platform_device.h>
21 #include <linux/seq_file.h>
22 
23 #include <linux/mfd/wm831x/core.h>
24 #include <linux/mfd/wm831x/pdata.h>
25 #include <linux/mfd/wm831x/gpio.h>
26 #include <linux/mfd/wm831x/irq.h>
27 
28 struct wm831x_gpio {
29  struct wm831x *wm831x;
30  struct gpio_chip gpio_chip;
31 };
32 
33 static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
34 {
35  return container_of(chip, struct wm831x_gpio, gpio_chip);
36 }
37 
38 static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
39 {
40  struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
41  struct wm831x *wm831x = wm831x_gpio->wm831x;
42  int val = WM831X_GPN_DIR;
43 
44  if (wm831x->has_gpio_ena)
45  val |= WM831X_GPN_TRI;
46 
47  return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
48  WM831X_GPN_DIR | WM831X_GPN_TRI |
49  WM831X_GPN_FN_MASK, val);
50 }
51 
52 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
53 {
54  struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
55  struct wm831x *wm831x = wm831x_gpio->wm831x;
56  int ret;
57 
58  ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
59  if (ret < 0)
60  return ret;
61 
62  if (ret & 1 << offset)
63  return 1;
64  else
65  return 0;
66 }
67 
68 static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
69 {
70  struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
71  struct wm831x *wm831x = wm831x_gpio->wm831x;
72 
73  wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
74  value << offset);
75 }
76 
77 static int wm831x_gpio_direction_out(struct gpio_chip *chip,
78  unsigned offset, int value)
79 {
80  struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
81  struct wm831x *wm831x = wm831x_gpio->wm831x;
82  int val = 0;
83  int ret;
84 
85  if (wm831x->has_gpio_ena)
86  val |= WM831X_GPN_TRI;
87 
88  ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
89  WM831X_GPN_DIR | WM831X_GPN_TRI |
90  WM831X_GPN_FN_MASK, val);
91  if (ret < 0)
92  return ret;
93 
94  /* Can only set GPIO state once it's in output mode */
95  wm831x_gpio_set(chip, offset, value);
96 
97  return 0;
98 }
99 
100 static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
101 {
102  struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
103  struct wm831x *wm831x = wm831x_gpio->wm831x;
104 
105  return irq_create_mapping(wm831x->irq_domain,
106  WM831X_IRQ_GPIO_1 + offset);
107 }
108 
109 static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
110  unsigned debounce)
111 {
112  struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
113  struct wm831x *wm831x = wm831x_gpio->wm831x;
114  int reg = WM831X_GPIO1_CONTROL + offset;
115  int ret, fn;
116 
117  ret = wm831x_reg_read(wm831x, reg);
118  if (ret < 0)
119  return ret;
120 
121  switch (ret & WM831X_GPN_FN_MASK) {
122  case 0:
123  case 1:
124  break;
125  default:
126  /* Not in GPIO mode */
127  return -EBUSY;
128  }
129 
130  if (debounce >= 32 && debounce <= 64)
131  fn = 0;
132  else if (debounce >= 4000 && debounce <= 8000)
133  fn = 1;
134  else
135  return -EINVAL;
136 
137  return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
138 }
139 
140 #ifdef CONFIG_DEBUG_FS
141 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
142 {
143  struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
144  struct wm831x *wm831x = wm831x_gpio->wm831x;
145  int i, tristated;
146 
147  for (i = 0; i < chip->ngpio; i++) {
148  int gpio = i + chip->base;
149  int reg;
150  const char *label, *pull, *powerdomain;
151 
152  /* We report the GPIO even if it's not requested since
153  * we're also reporting things like alternate
154  * functions which apply even when the GPIO is not in
155  * use as a GPIO.
156  */
157  label = gpiochip_is_requested(chip, i);
158  if (!label)
159  label = "Unrequested";
160 
161  seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
162 
163  reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
164  if (reg < 0) {
165  dev_err(wm831x->dev,
166  "GPIO control %d read failed: %d\n",
167  gpio, reg);
168  seq_printf(s, "\n");
169  continue;
170  }
171 
172  switch (reg & WM831X_GPN_PULL_MASK) {
173  case WM831X_GPIO_PULL_NONE:
174  pull = "nopull";
175  break;
176  case WM831X_GPIO_PULL_DOWN:
177  pull = "pulldown";
178  break;
179  case WM831X_GPIO_PULL_UP:
180  pull = "pullup";
181  break;
182  default:
183  pull = "INVALID PULL";
184  break;
185  }
186 
187  switch (i + 1) {
188  case 1 ... 3:
189  case 7 ... 9:
190  if (reg & WM831X_GPN_PWR_DOM)
191  powerdomain = "VPMIC";
192  else
193  powerdomain = "DBVDD";
194  break;
195 
196  case 4 ... 6:
197  case 10 ... 12:
198  if (reg & WM831X_GPN_PWR_DOM)
199  powerdomain = "SYSVDD";
200  else
201  powerdomain = "DBVDD";
202  break;
203 
204  case 13 ... 16:
205  powerdomain = "TPVDD";
206  break;
207 
208  default:
209  BUG();
210  break;
211  }
212 
213  tristated = reg & WM831X_GPN_TRI;
214  if (wm831x->has_gpio_ena)
215  tristated = !tristated;
216 
217  seq_printf(s, " %s %s %s %s%s\n"
218  " %s%s (0x%4x)\n",
219  reg & WM831X_GPN_DIR ? "in" : "out",
220  wm831x_gpio_get(chip, i) ? "high" : "low",
221  pull,
222  powerdomain,
223  reg & WM831X_GPN_POL ? "" : " inverted",
224  reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
225  tristated ? " tristated" : "",
226  reg);
227  }
228 }
229 #else
230 #define wm831x_gpio_dbg_show NULL
231 #endif
232 
233 static struct gpio_chip template_chip = {
234  .label = "wm831x",
235  .owner = THIS_MODULE,
236  .direction_input = wm831x_gpio_direction_in,
237  .get = wm831x_gpio_get,
238  .direction_output = wm831x_gpio_direction_out,
239  .set = wm831x_gpio_set,
240  .to_irq = wm831x_gpio_to_irq,
241  .set_debounce = wm831x_gpio_set_debounce,
242  .dbg_show = wm831x_gpio_dbg_show,
243  .can_sleep = 1,
244 };
245 
246 static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
247 {
248  struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
249  struct wm831x_pdata *pdata = wm831x->dev->platform_data;
250  struct wm831x_gpio *wm831x_gpio;
251  int ret;
252 
253  wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
254  GFP_KERNEL);
255  if (wm831x_gpio == NULL)
256  return -ENOMEM;
257 
258  wm831x_gpio->wm831x = wm831x;
259  wm831x_gpio->gpio_chip = template_chip;
260  wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
261  wm831x_gpio->gpio_chip.dev = &pdev->dev;
262  if (pdata && pdata->gpio_base)
263  wm831x_gpio->gpio_chip.base = pdata->gpio_base;
264  else
265  wm831x_gpio->gpio_chip.base = -1;
266 
267  ret = gpiochip_add(&wm831x_gpio->gpio_chip);
268  if (ret < 0) {
269  dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
270  return ret;
271  }
272 
273  platform_set_drvdata(pdev, wm831x_gpio);
274 
275  return ret;
276 }
277 
278 static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
279 {
280  struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
281 
282  return gpiochip_remove(&wm831x_gpio->gpio_chip);
283 }
284 
285 static struct platform_driver wm831x_gpio_driver = {
286  .driver.name = "wm831x-gpio",
287  .driver.owner = THIS_MODULE,
288  .probe = wm831x_gpio_probe,
289  .remove = __devexit_p(wm831x_gpio_remove),
290 };
291 
292 static int __init wm831x_gpio_init(void)
293 {
294  return platform_driver_register(&wm831x_gpio_driver);
295 }
296 subsys_initcall(wm831x_gpio_init);
297 
298 static void __exit wm831x_gpio_exit(void)
299 {
300  platform_driver_unregister(&wm831x_gpio_driver);
301 }
302 module_exit(wm831x_gpio_exit);
303 
304 MODULE_AUTHOR("Mark Brown <[email protected]>");
305 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
306 MODULE_LICENSE("GPL");
307 MODULE_ALIAS("platform:wm831x-gpio");
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