1 /*
2 * twl4030_gpio.c -- access to GPIOs on TWL4030/TPS659x0 chips
3 *
4 * Copyright (C) 2006-2007 Texas Instruments, Inc.
5 * Copyright (C) 2006 MontaVista Software, Inc.
6 *
7 * Code re-arranged and cleaned up by:
8 * Syed Mohammed Khasim <x0khasim@ti.com>
9 *
10 * Initial Code:
11 * Andy Lowe / Nishanth Menon
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 */
27
28 #include <linux/module.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/kthread.h>
32 #include <linux/irq.h>
33 #include <linux/gpio.h>
34 #include <linux/platform_device.h>
35 #include <linux/slab.h>
36
37 #include <linux/i2c/twl4030.h>
38
39
40 /*
41 * The GPIO "subchip" supports 18 GPIOs which can be configured as
42 * inputs or outputs, with pullups or pulldowns on each pin. Each
43 * GPIO can trigger interrupts on either or both edges.
44 *
45 * GPIO interrupts can be fed to either of two IRQ lines; this is
46 * intended to support multiple hosts.
47 *
48 * There are also two LED pins used sometimes as output-only GPIOs.
49 */
50
51
52 static struct gpio_chip twl_gpiochip;
53 static int twl4030_gpio_irq_base;
54
55 /* genirq interfaces are not available to modules */
56 #ifdef MODULE
57 #define is_module() true
58 #else
59 #define is_module() false
60 #endif
61
62 /* GPIO_CTRL Fields */
63 #define MASK_GPIO_CTRL_GPIO0CD1 BIT(0)
64 #define MASK_GPIO_CTRL_GPIO1CD2 BIT(1)
65 #define MASK_GPIO_CTRL_GPIO_ON BIT(2)
66
67 /* Mask for GPIO registers when aggregated into a 32-bit integer */
68 #define GPIO_32_MASK 0x0003ffff
69
70 /* Data structures */
71 static DEFINE_MUTEX(gpio_lock);
72
73 /* store usage of each GPIO. - each bit represents one GPIO */
74 static unsigned int gpio_usage_count;
75
76 /*----------------------------------------------------------------------*/
77
78 /*
79 * To configure TWL4030 GPIO module registers
80 */
gpio_twl4030_write(u8 address,u8 data)81 static inline int gpio_twl4030_write(u8 address, u8 data)
82 {
83 return twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
84 }
85
86 /*----------------------------------------------------------------------*/
87
88 /*
89 * LED register offsets (use TWL4030_MODULE_{LED,PWMA,PWMB}))
90 * PWMs A and B are dedicated to LEDs A and B, respectively.
91 */
92
93 #define TWL4030_LED_LEDEN 0x0
94
95 /* LEDEN bits */
96 #define LEDEN_LEDAON BIT(0)
97 #define LEDEN_LEDBON BIT(1)
98 #define LEDEN_LEDAEXT BIT(2)
99 #define LEDEN_LEDBEXT BIT(3)
100 #define LEDEN_LEDAPWM BIT(4)
101 #define LEDEN_LEDBPWM BIT(5)
102 #define LEDEN_PWM_LENGTHA BIT(6)
103 #define LEDEN_PWM_LENGTHB BIT(7)
104
105 #define TWL4030_PWMx_PWMxON 0x0
106 #define TWL4030_PWMx_PWMxOFF 0x1
107
108 #define PWMxON_LENGTH BIT(7)
109
110 /*----------------------------------------------------------------------*/
111
112 /*
113 * To read a TWL4030 GPIO module register
114 */
gpio_twl4030_read(u8 address)115 static inline int gpio_twl4030_read(u8 address)
116 {
117 u8 data;
118 int ret = 0;
119
120 ret = twl4030_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
121 return (ret < 0) ? ret : data;
122 }
123
124 /*----------------------------------------------------------------------*/
125
126 static u8 cached_leden; /* protected by gpio_lock */
127
128 /* The LED lines are open drain outputs ... a FET pulls to GND, so an
129 * external pullup is needed. We could also expose the integrated PWM
130 * as a LED brightness control; we initialize it as "always on".
131 */
twl4030_led_set_value(int led,int value)132 static void twl4030_led_set_value(int led, int value)
133 {
134 u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
135 int status;
136
137 if (led)
138 mask <<= 1;
139
140 mutex_lock(&gpio_lock);
141 if (value)
142 cached_leden &= ~mask;
143 else
144 cached_leden |= mask;
145 status = twl4030_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
146 TWL4030_LED_LEDEN);
147 mutex_unlock(&gpio_lock);
148 }
149
twl4030_set_gpio_direction(int gpio,int is_input)150 static int twl4030_set_gpio_direction(int gpio, int is_input)
151 {
152 u8 d_bnk = gpio >> 3;
153 u8 d_msk = BIT(gpio & 0x7);
154 u8 reg = 0;
155 u8 base = REG_GPIODATADIR1 + d_bnk;
156 int ret = 0;
157
158 mutex_lock(&gpio_lock);
159 ret = gpio_twl4030_read(base);
160 if (ret >= 0) {
161 if (is_input)
162 reg = ret & ~d_msk;
163 else
164 reg = ret | d_msk;
165
166 ret = gpio_twl4030_write(base, reg);
167 }
168 mutex_unlock(&gpio_lock);
169 return ret;
170 }
171
twl4030_set_gpio_dataout(int gpio,int enable)172 static int twl4030_set_gpio_dataout(int gpio, int enable)
173 {
174 u8 d_bnk = gpio >> 3;
175 u8 d_msk = BIT(gpio & 0x7);
176 u8 base = 0;
177
178 if (enable)
179 base = REG_SETGPIODATAOUT1 + d_bnk;
180 else
181 base = REG_CLEARGPIODATAOUT1 + d_bnk;
182
183 return gpio_twl4030_write(base, d_msk);
184 }
185
twl4030_get_gpio_datain(int gpio)186 static int twl4030_get_gpio_datain(int gpio)
187 {
188 u8 d_bnk = gpio >> 3;
189 u8 d_off = gpio & 0x7;
190 u8 base = 0;
191 int ret = 0;
192
193 if (unlikely((gpio >= TWL4030_GPIO_MAX)
194 || !(gpio_usage_count & BIT(gpio))))
195 return -EPERM;
196
197 base = REG_GPIODATAIN1 + d_bnk;
198 ret = gpio_twl4030_read(base);
199 if (ret > 0)
200 ret = (ret >> d_off) & 0x1;
201
202 return ret;
203 }
204
205 /*----------------------------------------------------------------------*/
206
twl_request(struct gpio_chip * chip,unsigned offset)207 static int twl_request(struct gpio_chip *chip, unsigned offset)
208 {
209 int status = 0;
210
211 mutex_lock(&gpio_lock);
212
213 /* Support the two LED outputs as output-only GPIOs. */
214 if (offset >= TWL4030_GPIO_MAX) {
215 u8 ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT
216 | LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;
217 u8 module = TWL4030_MODULE_PWMA;
218
219 offset -= TWL4030_GPIO_MAX;
220 if (offset) {
221 ledclr_mask <<= 1;
222 module = TWL4030_MODULE_PWMB;
223 }
224
225 /* initialize PWM to always-drive */
226 status = twl4030_i2c_write_u8(module, 0x7f,
227 TWL4030_PWMx_PWMxOFF);
228 if (status < 0)
229 goto done;
230 status = twl4030_i2c_write_u8(module, 0x7f,
231 TWL4030_PWMx_PWMxON);
232 if (status < 0)
233 goto done;
234
235 /* init LED to not-driven (high) */
236 module = TWL4030_MODULE_LED;
237 status = twl4030_i2c_read_u8(module, &cached_leden,
238 TWL4030_LED_LEDEN);
239 if (status < 0)
240 goto done;
241 cached_leden &= ~ledclr_mask;
242 status = twl4030_i2c_write_u8(module, cached_leden,
243 TWL4030_LED_LEDEN);
244 if (status < 0)
245 goto done;
246
247 status = 0;
248 goto done;
249 }
250
251 /* on first use, turn GPIO module "on" */
252 if (!gpio_usage_count) {
253 struct twl4030_gpio_platform_data *pdata;
254 u8 value = MASK_GPIO_CTRL_GPIO_ON;
255
256 /* optionally have the first two GPIOs switch vMMC1
257 * and vMMC2 power supplies based on card presence.
258 */
259 pdata = chip->dev->platform_data;
260 value |= pdata->mmc_cd & 0x03;
261
262 status = gpio_twl4030_write(REG_GPIO_CTRL, value);
263 }
264
265 if (!status)
266 gpio_usage_count |= (0x1 << offset);
267
268 done:
269 mutex_unlock(&gpio_lock);
270 return status;
271 }
272
twl_free(struct gpio_chip * chip,unsigned offset)273 static void twl_free(struct gpio_chip *chip, unsigned offset)
274 {
275 if (offset >= TWL4030_GPIO_MAX) {
276 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
277 return;
278 }
279
280 mutex_lock(&gpio_lock);
281
282 gpio_usage_count &= ~BIT(offset);
283
284 /* on last use, switch off GPIO module */
285 if (!gpio_usage_count)
286 gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
287
288 mutex_unlock(&gpio_lock);
289 }
290
twl_direction_in(struct gpio_chip * chip,unsigned offset)291 static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
292 {
293 return (offset < TWL4030_GPIO_MAX)
294 ? twl4030_set_gpio_direction(offset, 1)
295 : -EINVAL;
296 }
297
twl_get(struct gpio_chip * chip,unsigned offset)298 static int twl_get(struct gpio_chip *chip, unsigned offset)
299 {
300 int status = 0;
301
302 if (offset < TWL4030_GPIO_MAX)
303 status = twl4030_get_gpio_datain(offset);
304 else if (offset == TWL4030_GPIO_MAX)
305 status = cached_leden & LEDEN_LEDAON;
306 else
307 status = cached_leden & LEDEN_LEDBON;
308 return (status < 0) ? 0 : status;
309 }
310
twl_direction_out(struct gpio_chip * chip,unsigned offset,int value)311 static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
312 {
313 if (offset < TWL4030_GPIO_MAX) {
314 twl4030_set_gpio_dataout(offset, value);
315 return twl4030_set_gpio_direction(offset, 0);
316 } else {
317 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
318 return 0;
319 }
320 }
321
twl_set(struct gpio_chip * chip,unsigned offset,int value)322 static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
323 {
324 if (offset < TWL4030_GPIO_MAX)
325 twl4030_set_gpio_dataout(offset, value);
326 else
327 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
328 }
329
twl_to_irq(struct gpio_chip * chip,unsigned offset)330 static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
331 {
332 return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))
333 ? (twl4030_gpio_irq_base + offset)
334 : -EINVAL;
335 }
336
337 static struct gpio_chip twl_gpiochip = {
338 .label = "twl4030",
339 .owner = THIS_MODULE,
340 .request = twl_request,
341 .free = twl_free,
342 .direction_input = twl_direction_in,
343 .get = twl_get,
344 .direction_output = twl_direction_out,
345 .set = twl_set,
346 .to_irq = twl_to_irq,
347 .can_sleep = 1,
348 };
349
350 /*----------------------------------------------------------------------*/
351
gpio_twl4030_pulls(u32 ups,u32 downs)352 static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs)
353 {
354 u8 message[6];
355 unsigned i, gpio_bit;
356
357 /* For most pins, a pulldown was enabled by default.
358 * We should have data that's specific to this board.
359 */
360 for (gpio_bit = 1, i = 1; i < 6; i++) {
361 u8 bit_mask;
362 unsigned j;
363
364 for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
365 if (ups & gpio_bit)
366 bit_mask |= 1 << (j + 1);
367 else if (downs & gpio_bit)
368 bit_mask |= 1 << (j + 0);
369 }
370 message[i] = bit_mask;
371 }
372
373 return twl4030_i2c_write(TWL4030_MODULE_GPIO, message,
374 REG_GPIOPUPDCTR1, 5);
375 }
376
gpio_twl4030_debounce(u32 debounce,u8 mmc_cd)377 static int __devinit gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
378 {
379 u8 message[4];
380
381 /* 30 msec of debouncing is always used for MMC card detect,
382 * and is optional for everything else.
383 */
384 message[1] = (debounce & 0xff) | (mmc_cd & 0x03);
385 debounce >>= 8;
386 message[2] = (debounce & 0xff);
387 debounce >>= 8;
388 message[3] = (debounce & 0x03);
389
390 return twl4030_i2c_write(TWL4030_MODULE_GPIO, message,
391 REG_GPIO_DEBEN1, 3);
392 }
393
394 static int gpio_twl4030_remove(struct platform_device *pdev);
395
gpio_twl4030_probe(struct platform_device * pdev)396 static int __devinit gpio_twl4030_probe(struct platform_device *pdev)
397 {
398 struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
399 int ret;
400
401 /* maybe setup IRQs */
402 if (pdata->irq_base) {
403 if (is_module()) {
404 dev_err(&pdev->dev,
405 "can't dispatch IRQs from modules\n");
406 goto no_irqs;
407 }
408 ret = twl4030_sih_setup(TWL4030_MODULE_GPIO);
409 if (ret < 0)
410 return ret;
411 WARN_ON(ret != pdata->irq_base);
412 twl4030_gpio_irq_base = ret;
413 }
414
415 no_irqs:
416 /*
417 * NOTE: boards may waste power if they don't set pullups
418 * and pulldowns correctly ... default for non-ULPI pins is
419 * pulldown, and some other pins may have external pullups
420 * or pulldowns. Careful!
421 */
422 ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
423 if (ret)
424 dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
425 pdata->pullups, pdata->pulldowns,
426 ret);
427
428 ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
429 if (ret)
430 dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
431 pdata->debounce, pdata->mmc_cd,
432 ret);
433
434 twl_gpiochip.base = pdata->gpio_base;
435 twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
436 twl_gpiochip.dev = &pdev->dev;
437
438 /* NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
439 * is (still) clear if use_leds is set.
440 */
441 if (pdata->use_leds)
442 twl_gpiochip.ngpio += 2;
443
444 ret = gpiochip_add(&twl_gpiochip);
445 if (ret < 0) {
446 dev_err(&pdev->dev,
447 "could not register gpiochip, %d\n",
448 ret);
449 twl_gpiochip.ngpio = 0;
450 gpio_twl4030_remove(pdev);
451 } else if (pdata->setup) {
452 int status;
453
454 status = pdata->setup(&pdev->dev,
455 pdata->gpio_base, TWL4030_GPIO_MAX);
456 if (status)
457 dev_dbg(&pdev->dev, "setup --> %d\n", status);
458 }
459
460 return ret;
461 }
462
gpio_twl4030_remove(struct platform_device * pdev)463 static int __devexit gpio_twl4030_remove(struct platform_device *pdev)
464 {
465 struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
466 int status;
467
468 if (pdata->teardown) {
469 status = pdata->teardown(&pdev->dev,
470 pdata->gpio_base, TWL4030_GPIO_MAX);
471 if (status) {
472 dev_dbg(&pdev->dev, "teardown --> %d\n", status);
473 return status;
474 }
475 }
476
477 status = gpiochip_remove(&twl_gpiochip);
478 if (status < 0)
479 return status;
480
481 if (is_module())
482 return 0;
483
484 /* REVISIT no support yet for deregistering all the IRQs */
485 WARN_ON(1);
486 return -EIO;
487 }
488
489 /* Note: this hardware lives inside an I2C-based multi-function device. */
490 MODULE_ALIAS("platform:twl4030_gpio");
491
492 static struct platform_driver gpio_twl4030_driver = {
493 .driver.name = "twl4030_gpio",
494 .driver.owner = THIS_MODULE,
495 .probe = gpio_twl4030_probe,
496 .remove = __devexit_p(gpio_twl4030_remove),
497 };
498
gpio_twl4030_init(void)499 static int __init gpio_twl4030_init(void)
500 {
501 return platform_driver_register(&gpio_twl4030_driver);
502 }
503 subsys_initcall(gpio_twl4030_init);
504
gpio_twl4030_exit(void)505 static void __exit gpio_twl4030_exit(void)
506 {
507 platform_driver_unregister(&gpio_twl4030_driver);
508 }
509 module_exit(gpio_twl4030_exit);
510
511 MODULE_AUTHOR("Texas Instruments, Inc.");
512 MODULE_DESCRIPTION("GPIO interface for TWL4030");
513 MODULE_LICENSE("GPL");
514