Root/drivers/gpio/gpio-twl4030.c

1/*
2 * 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/of.h>
36#include <linux/irqdomain.h>
37
38#include <linux/i2c/twl.h>
39
40
41/*
42 * The GPIO "subchip" supports 18 GPIOs which can be configured as
43 * inputs or outputs, with pullups or pulldowns on each pin. Each
44 * GPIO can trigger interrupts on either or both edges.
45 *
46 * GPIO interrupts can be fed to either of two IRQ lines; this is
47 * intended to support multiple hosts.
48 *
49 * There are also two LED pins used sometimes as output-only GPIOs.
50 */
51
52
53static struct gpio_chip twl_gpiochip;
54static int twl4030_gpio_irq_base;
55
56/* genirq interfaces are not available to modules */
57#ifdef MODULE
58#define is_module() true
59#else
60#define is_module() false
61#endif
62
63/* GPIO_CTRL Fields */
64#define MASK_GPIO_CTRL_GPIO0CD1 BIT(0)
65#define MASK_GPIO_CTRL_GPIO1CD2 BIT(1)
66#define MASK_GPIO_CTRL_GPIO_ON BIT(2)
67
68/* Mask for GPIO registers when aggregated into a 32-bit integer */
69#define GPIO_32_MASK 0x0003ffff
70
71/* Data structures */
72static DEFINE_MUTEX(gpio_lock);
73
74/* store usage of each GPIO. - each bit represents one GPIO */
75static unsigned int gpio_usage_count;
76
77/*----------------------------------------------------------------------*/
78
79/*
80 * To configure TWL4030 GPIO module registers
81 */
82static inline int gpio_twl4030_write(u8 address, u8 data)
83{
84    return twl_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
85}
86
87/*----------------------------------------------------------------------*/
88
89/*
90 * LED register offsets (use TWL4030_MODULE_{LED,PWMA,PWMB}))
91 * PWMs A and B are dedicated to LEDs A and B, respectively.
92 */
93
94#define TWL4030_LED_LEDEN 0x0
95
96/* LEDEN bits */
97#define LEDEN_LEDAON BIT(0)
98#define LEDEN_LEDBON BIT(1)
99#define LEDEN_LEDAEXT BIT(2)
100#define LEDEN_LEDBEXT BIT(3)
101#define LEDEN_LEDAPWM BIT(4)
102#define LEDEN_LEDBPWM BIT(5)
103#define LEDEN_PWM_LENGTHA BIT(6)
104#define LEDEN_PWM_LENGTHB BIT(7)
105
106#define TWL4030_PWMx_PWMxON 0x0
107#define TWL4030_PWMx_PWMxOFF 0x1
108
109#define PWMxON_LENGTH BIT(7)
110
111/*----------------------------------------------------------------------*/
112
113/*
114 * To read a TWL4030 GPIO module register
115 */
116static inline int gpio_twl4030_read(u8 address)
117{
118    u8 data;
119    int ret = 0;
120
121    ret = twl_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
122    return (ret < 0) ? ret : data;
123}
124
125/*----------------------------------------------------------------------*/
126
127static u8 cached_leden; /* protected by gpio_lock */
128
129/* The LED lines are open drain outputs ... a FET pulls to GND, so an
130 * external pullup is needed. We could also expose the integrated PWM
131 * as a LED brightness control; we initialize it as "always on".
132 */
133static void twl4030_led_set_value(int led, int value)
134{
135    u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
136    int status;
137
138    if (led)
139        mask <<= 1;
140
141    mutex_lock(&gpio_lock);
142    if (value)
143        cached_leden &= ~mask;
144    else
145        cached_leden |= mask;
146    status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
147            TWL4030_LED_LEDEN);
148    mutex_unlock(&gpio_lock);
149}
150
151static int twl4030_set_gpio_direction(int gpio, int is_input)
152{
153    u8 d_bnk = gpio >> 3;
154    u8 d_msk = BIT(gpio & 0x7);
155    u8 reg = 0;
156    u8 base = REG_GPIODATADIR1 + d_bnk;
157    int ret = 0;
158
159    mutex_lock(&gpio_lock);
160    ret = gpio_twl4030_read(base);
161    if (ret >= 0) {
162        if (is_input)
163            reg = ret & ~d_msk;
164        else
165            reg = ret | d_msk;
166
167        ret = gpio_twl4030_write(base, reg);
168    }
169    mutex_unlock(&gpio_lock);
170    return ret;
171}
172
173static int twl4030_set_gpio_dataout(int gpio, int enable)
174{
175    u8 d_bnk = gpio >> 3;
176    u8 d_msk = BIT(gpio & 0x7);
177    u8 base = 0;
178
179    if (enable)
180        base = REG_SETGPIODATAOUT1 + d_bnk;
181    else
182        base = REG_CLEARGPIODATAOUT1 + d_bnk;
183
184    return gpio_twl4030_write(base, d_msk);
185}
186
187static int twl4030_get_gpio_datain(int gpio)
188{
189    u8 d_bnk = gpio >> 3;
190    u8 d_off = gpio & 0x7;
191    u8 base = 0;
192    int ret = 0;
193
194    if (unlikely((gpio >= TWL4030_GPIO_MAX)
195        || !(gpio_usage_count & BIT(gpio))))
196        return -EPERM;
197
198    base = REG_GPIODATAIN1 + d_bnk;
199    ret = gpio_twl4030_read(base);
200    if (ret > 0)
201        ret = (ret >> d_off) & 0x1;
202
203    return ret;
204}
205
206/*----------------------------------------------------------------------*/
207
208static int twl_request(struct gpio_chip *chip, unsigned offset)
209{
210    int status = 0;
211
212    mutex_lock(&gpio_lock);
213
214    /* Support the two LED outputs as output-only GPIOs. */
215    if (offset >= TWL4030_GPIO_MAX) {
216        u8 ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT
217                | LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;
218        u8 module = TWL4030_MODULE_PWMA;
219
220        offset -= TWL4030_GPIO_MAX;
221        if (offset) {
222            ledclr_mask <<= 1;
223            module = TWL4030_MODULE_PWMB;
224        }
225
226        /* initialize PWM to always-drive */
227        status = twl_i2c_write_u8(module, 0x7f,
228                TWL4030_PWMx_PWMxOFF);
229        if (status < 0)
230            goto done;
231        status = twl_i2c_write_u8(module, 0x7f,
232                TWL4030_PWMx_PWMxON);
233        if (status < 0)
234            goto done;
235
236        /* init LED to not-driven (high) */
237        module = TWL4030_MODULE_LED;
238        status = twl_i2c_read_u8(module, &cached_leden,
239                TWL4030_LED_LEDEN);
240        if (status < 0)
241            goto done;
242        cached_leden &= ~ledclr_mask;
243        status = twl_i2c_write_u8(module, cached_leden,
244                TWL4030_LED_LEDEN);
245        if (status < 0)
246            goto done;
247
248        status = 0;
249        goto done;
250    }
251
252    /* on first use, turn GPIO module "on" */
253    if (!gpio_usage_count) {
254        struct twl4030_gpio_platform_data *pdata;
255        u8 value = MASK_GPIO_CTRL_GPIO_ON;
256
257        /* optionally have the first two GPIOs switch vMMC1
258         * and vMMC2 power supplies based on card presence.
259         */
260        pdata = chip->dev->platform_data;
261        if (pdata)
262            value |= pdata->mmc_cd & 0x03;
263
264        status = gpio_twl4030_write(REG_GPIO_CTRL, value);
265    }
266
267    if (!status)
268        gpio_usage_count |= (0x1 << offset);
269
270done:
271    mutex_unlock(&gpio_lock);
272    return status;
273}
274
275static void twl_free(struct gpio_chip *chip, unsigned offset)
276{
277    if (offset >= TWL4030_GPIO_MAX) {
278        twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
279        return;
280    }
281
282    mutex_lock(&gpio_lock);
283
284    gpio_usage_count &= ~BIT(offset);
285
286    /* on last use, switch off GPIO module */
287    if (!gpio_usage_count)
288        gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
289
290    mutex_unlock(&gpio_lock);
291}
292
293static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
294{
295    return (offset < TWL4030_GPIO_MAX)
296        ? twl4030_set_gpio_direction(offset, 1)
297        : -EINVAL;
298}
299
300static int twl_get(struct gpio_chip *chip, unsigned offset)
301{
302    int status = 0;
303
304    if (offset < TWL4030_GPIO_MAX)
305        status = twl4030_get_gpio_datain(offset);
306    else if (offset == TWL4030_GPIO_MAX)
307        status = cached_leden & LEDEN_LEDAON;
308    else
309        status = cached_leden & LEDEN_LEDBON;
310    return (status < 0) ? 0 : status;
311}
312
313static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
314{
315    if (offset < TWL4030_GPIO_MAX) {
316        twl4030_set_gpio_dataout(offset, value);
317        return twl4030_set_gpio_direction(offset, 0);
318    } else {
319        twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
320        return 0;
321    }
322}
323
324static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
325{
326    if (offset < TWL4030_GPIO_MAX)
327        twl4030_set_gpio_dataout(offset, value);
328    else
329        twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
330}
331
332static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
333{
334    return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))
335        ? (twl4030_gpio_irq_base + offset)
336        : -EINVAL;
337}
338
339static struct gpio_chip twl_gpiochip = {
340    .label = "twl4030",
341    .owner = THIS_MODULE,
342    .request = twl_request,
343    .free = twl_free,
344    .direction_input = twl_direction_in,
345    .get = twl_get,
346    .direction_output = twl_direction_out,
347    .set = twl_set,
348    .to_irq = twl_to_irq,
349    .can_sleep = 1,
350};
351
352/*----------------------------------------------------------------------*/
353
354static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs)
355{
356    u8 message[6];
357    unsigned i, gpio_bit;
358
359    /* For most pins, a pulldown was enabled by default.
360     * We should have data that's specific to this board.
361     */
362    for (gpio_bit = 1, i = 1; i < 6; i++) {
363        u8 bit_mask;
364        unsigned j;
365
366        for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
367            if (ups & gpio_bit)
368                bit_mask |= 1 << (j + 1);
369            else if (downs & gpio_bit)
370                bit_mask |= 1 << (j + 0);
371        }
372        message[i] = bit_mask;
373    }
374
375    return twl_i2c_write(TWL4030_MODULE_GPIO, message,
376                REG_GPIOPUPDCTR1, 5);
377}
378
379static int __devinit gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
380{
381    u8 message[4];
382
383    /* 30 msec of debouncing is always used for MMC card detect,
384     * and is optional for everything else.
385     */
386    message[1] = (debounce & 0xff) | (mmc_cd & 0x03);
387    debounce >>= 8;
388    message[2] = (debounce & 0xff);
389    debounce >>= 8;
390    message[3] = (debounce & 0x03);
391
392    return twl_i2c_write(TWL4030_MODULE_GPIO, message,
393                REG_GPIO_DEBEN1, 3);
394}
395
396static int gpio_twl4030_remove(struct platform_device *pdev);
397
398static int __devinit gpio_twl4030_probe(struct platform_device *pdev)
399{
400    struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
401    struct device_node *node = pdev->dev.of_node;
402    int ret, irq_base;
403
404    /* maybe setup IRQs */
405    if (is_module()) {
406        dev_err(&pdev->dev, "can't dispatch IRQs from modules\n");
407        goto no_irqs;
408    }
409
410    irq_base = irq_alloc_descs(-1, 0, TWL4030_GPIO_MAX, 0);
411    if (irq_base < 0) {
412        dev_err(&pdev->dev, "Failed to alloc irq_descs\n");
413        return irq_base;
414    }
415
416    irq_domain_add_legacy(node, TWL4030_GPIO_MAX, irq_base, 0,
417                  &irq_domain_simple_ops, NULL);
418
419    ret = twl4030_sih_setup(&pdev->dev, TWL4030_MODULE_GPIO, irq_base);
420    if (ret < 0)
421        return ret;
422
423    twl4030_gpio_irq_base = irq_base;
424
425no_irqs:
426    twl_gpiochip.base = -1;
427    twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
428    twl_gpiochip.dev = &pdev->dev;
429
430    if (pdata) {
431        twl_gpiochip.base = pdata->gpio_base;
432
433        /*
434         * NOTE: boards may waste power if they don't set pullups
435         * and pulldowns correctly ... default for non-ULPI pins is
436         * pulldown, and some other pins may have external pullups
437         * or pulldowns. Careful!
438         */
439        ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
440        if (ret)
441            dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
442                    pdata->pullups, pdata->pulldowns,
443                    ret);
444
445        ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
446        if (ret)
447            dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
448                    pdata->debounce, pdata->mmc_cd,
449                    ret);
450
451        /*
452         * NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
453         * is (still) clear if use_leds is set.
454         */
455        if (pdata->use_leds)
456            twl_gpiochip.ngpio += 2;
457    }
458
459    ret = gpiochip_add(&twl_gpiochip);
460    if (ret < 0) {
461        dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
462        twl_gpiochip.ngpio = 0;
463        gpio_twl4030_remove(pdev);
464    } else if (pdata && pdata->setup) {
465        int status;
466
467        status = pdata->setup(&pdev->dev,
468                pdata->gpio_base, TWL4030_GPIO_MAX);
469        if (status)
470            dev_dbg(&pdev->dev, "setup --> %d\n", status);
471    }
472
473    return ret;
474}
475
476/* Cannot use __devexit as gpio_twl4030_probe() calls us */
477static int gpio_twl4030_remove(struct platform_device *pdev)
478{
479    struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
480    int status;
481
482    if (pdata && pdata->teardown) {
483        status = pdata->teardown(&pdev->dev,
484                pdata->gpio_base, TWL4030_GPIO_MAX);
485        if (status) {
486            dev_dbg(&pdev->dev, "teardown --> %d\n", status);
487            return status;
488        }
489    }
490
491    status = gpiochip_remove(&twl_gpiochip);
492    if (status < 0)
493        return status;
494
495    if (is_module())
496        return 0;
497
498    /* REVISIT no support yet for deregistering all the IRQs */
499    WARN_ON(1);
500    return -EIO;
501}
502
503static const struct of_device_id twl_gpio_match[] = {
504    { .compatible = "ti,twl4030-gpio", },
505    { },
506};
507MODULE_DEVICE_TABLE(of, twl_gpio_match);
508
509/* Note: this hardware lives inside an I2C-based multi-function device. */
510MODULE_ALIAS("platform:twl4030_gpio");
511
512static struct platform_driver gpio_twl4030_driver = {
513    .driver = {
514        .name = "twl4030_gpio",
515        .owner = THIS_MODULE,
516        .of_match_table = of_match_ptr(twl_gpio_match),
517    },
518    .probe = gpio_twl4030_probe,
519    .remove = gpio_twl4030_remove,
520};
521
522static int __init gpio_twl4030_init(void)
523{
524    return platform_driver_register(&gpio_twl4030_driver);
525}
526subsys_initcall(gpio_twl4030_init);
527
528static void __exit gpio_twl4030_exit(void)
529{
530    platform_driver_unregister(&gpio_twl4030_driver);
531}
532module_exit(gpio_twl4030_exit);
533
534MODULE_AUTHOR("Texas Instruments, Inc.");
535MODULE_DESCRIPTION("GPIO interface for TWL4030");
536MODULE_LICENSE("GPL");
537

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