diff options
Diffstat (limited to 'drivers/gpio/twl4030-gpio.c')
| -rw-r--r-- | drivers/gpio/twl4030-gpio.c | 521 |
1 files changed, 521 insertions, 0 deletions
diff --git a/drivers/gpio/twl4030-gpio.c b/drivers/gpio/twl4030-gpio.c new file mode 100644 index 0000000..37d3eec --- /dev/null +++ b/drivers/gpio/twl4030-gpio.c @@ -0,0 +1,521 @@ +/* + * twl4030_gpio.c -- access to GPIOs on TWL4030/TPS659x0 chips + * + * Copyright (C) 2006-2007 Texas Instruments, Inc. + * Copyright (C) 2006 MontaVista Software, Inc. + * + * Code re-arranged and cleaned up by: + * Syed Mohammed Khasim <x0khasim@ti.com> + * + * Initial Code: + * Andy Lowe / Nishanth Menon + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kthread.h> +#include <linux/irq.h> +#include <linux/gpio.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include <linux/i2c/twl4030.h> + + +/* + * The GPIO "subchip" supports 18 GPIOs which can be configured as + * inputs or outputs, with pullups or pulldowns on each pin. Each + * GPIO can trigger interrupts on either or both edges. + * + * GPIO interrupts can be fed to either of two IRQ lines; this is + * intended to support multiple hosts. + * + * There are also two LED pins used sometimes as output-only GPIOs. + */ + + +static struct gpio_chip twl_gpiochip; +static int twl4030_gpio_irq_base; + +/* genirq interfaces are not available to modules */ +#ifdef MODULE +#define is_module() true +#else +#define is_module() false +#endif + +/* GPIO_CTRL Fields */ +#define MASK_GPIO_CTRL_GPIO0CD1 BIT(0) +#define MASK_GPIO_CTRL_GPIO1CD2 BIT(1) +#define MASK_GPIO_CTRL_GPIO_ON BIT(2) + +/* Mask for GPIO registers when aggregated into a 32-bit integer */ +#define GPIO_32_MASK 0x0003ffff + +/* Data structures */ +static DEFINE_MUTEX(gpio_lock); + +/* store usage of each GPIO. - each bit represents one GPIO */ +static unsigned int gpio_usage_count; + +/*----------------------------------------------------------------------*/ + +/* + * To configure TWL4030 GPIO module registers + */ +static inline int gpio_twl4030_write(u8 address, u8 data) +{ + return twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, data, address); +} + +/*----------------------------------------------------------------------*/ + +/* + * LED register offsets (use TWL4030_MODULE_{LED,PWMA,PWMB})) + * PWMs A and B are dedicated to LEDs A and B, respectively. + */ + +#define TWL4030_LED_LEDEN 0x0 + +/* LEDEN bits */ +#define LEDEN_LEDAON BIT(0) +#define LEDEN_LEDBON BIT(1) +#define LEDEN_LEDAEXT BIT(2) +#define LEDEN_LEDBEXT BIT(3) +#define LEDEN_LEDAPWM BIT(4) +#define LEDEN_LEDBPWM BIT(5) +#define LEDEN_PWM_LENGTHA BIT(6) +#define LEDEN_PWM_LENGTHB BIT(7) + +#define TWL4030_PWMx_PWMxON 0x0 +#define TWL4030_PWMx_PWMxOFF 0x1 + +#define PWMxON_LENGTH BIT(7) + +/*----------------------------------------------------------------------*/ + +/* + * To read a TWL4030 GPIO module register + */ +static inline int gpio_twl4030_read(u8 address) +{ + u8 data; + int ret = 0; + + ret = twl4030_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address); + return (ret < 0) ? ret : data; +} + +/*----------------------------------------------------------------------*/ + +static u8 cached_leden; /* protected by gpio_lock */ + +/* The LED lines are open drain outputs ... a FET pulls to GND, so an + * external pullup is needed. We could also expose the integrated PWM + * as a LED brightness control; we initialize it as "always on". + */ +static void twl4030_led_set_value(int led, int value) +{ + u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM; + int status; + + if (led) + mask <<= 1; + + mutex_lock(&gpio_lock); + if (value) + cached_leden &= ~mask; + else + cached_leden |= mask; + status = twl4030_i2c_write_u8(TWL4030_MODULE_LED, cached_leden, + TWL4030_LED_LEDEN); + mutex_unlock(&gpio_lock); +} + +static int twl4030_set_gpio_direction(int gpio, int is_input) +{ + u8 d_bnk = gpio >> 3; + u8 d_msk = BIT(gpio & 0x7); + u8 reg = 0; + u8 base = REG_GPIODATADIR1 + d_bnk; + int ret = 0; + + mutex_lock(&gpio_lock); + ret = gpio_twl4030_read(base); + if (ret >= 0) { + if (is_input) + reg = ret & ~d_msk; + else + reg = ret | d_msk; + + ret = gpio_twl4030_write(base, reg); + } + mutex_unlock(&gpio_lock); + return ret; +} + +static int twl4030_set_gpio_dataout(int gpio, int enable) +{ + u8 d_bnk = gpio >> 3; + u8 d_msk = BIT(gpio & 0x7); + u8 base = 0; + + if (enable) + base = REG_SETGPIODATAOUT1 + d_bnk; + else + base = REG_CLEARGPIODATAOUT1 + d_bnk; + + return gpio_twl4030_write(base, d_msk); +} + +static int twl4030_get_gpio_datain(int gpio) +{ + u8 d_bnk = gpio >> 3; + u8 d_off = gpio & 0x7; + u8 base = 0; + int ret = 0; + + if (unlikely((gpio >= TWL4030_GPIO_MAX) + || !(gpio_usage_count & BIT(gpio)))) + return -EPERM; + + base = REG_GPIODATAIN1 + d_bnk; + ret = gpio_twl4030_read(base); + if (ret > 0) + ret = (ret >> d_off) & 0x1; + + return ret; +} + +/* + * Configure debounce timing value for a GPIO pin on TWL4030 + */ +int twl4030_set_gpio_debounce(int gpio, int enable) +{ + u8 d_bnk = gpio >> 3; + u8 d_msk = BIT(gpio & 0x7); + u8 reg = 0; + u8 base = 0; + int ret = 0; + + if (unlikely((gpio >= TWL4030_GPIO_MAX) + || !(gpio_usage_count & BIT(gpio)))) + return -EPERM; + + base = REG_GPIO_DEBEN1 + d_bnk; + mutex_lock(&gpio_lock); + ret = gpio_twl4030_read(base); + if (ret >= 0) { + if (enable) + reg = ret | d_msk; + else + reg = ret & ~d_msk; + + ret = gpio_twl4030_write(base, reg); + } + mutex_unlock(&gpio_lock); + return ret; +} +EXPORT_SYMBOL(twl4030_set_gpio_debounce); + +/*----------------------------------------------------------------------*/ + +static int twl_request(struct gpio_chip *chip, unsigned offset) +{ + int status = 0; + + mutex_lock(&gpio_lock); + + /* Support the two LED outputs as output-only GPIOs. */ + if (offset >= TWL4030_GPIO_MAX) { + u8 ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT + | LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA; + u8 module = TWL4030_MODULE_PWMA; + + offset -= TWL4030_GPIO_MAX; + if (offset) { + ledclr_mask <<= 1; + module = TWL4030_MODULE_PWMB; + } + + /* initialize PWM to always-drive */ + status = twl4030_i2c_write_u8(module, 0x7f, + TWL4030_PWMx_PWMxOFF); + if (status < 0) + goto done; + status = twl4030_i2c_write_u8(module, 0x7f, + TWL4030_PWMx_PWMxON); + if (status < 0) + goto done; + + /* init LED to not-driven (high) */ + module = TWL4030_MODULE_LED; + status = twl4030_i2c_read_u8(module, &cached_leden, + TWL4030_LED_LEDEN); + if (status < 0) + goto done; + cached_leden &= ~ledclr_mask; + status = twl4030_i2c_write_u8(module, cached_leden, + TWL4030_LED_LEDEN); + if (status < 0) + goto done; + + status = 0; + goto done; + } + + /* on first use, turn GPIO module "on" */ + if (!gpio_usage_count) { + struct twl4030_gpio_platform_data *pdata; + u8 value = MASK_GPIO_CTRL_GPIO_ON; + + /* optionally have the first two GPIOs switch vMMC1 + * and vMMC2 power supplies based on card presence. + */ + pdata = chip->dev->platform_data; + value |= pdata->mmc_cd & 0x03; + + status = gpio_twl4030_write(REG_GPIO_CTRL, value); + } + + if (!status) + gpio_usage_count |= (0x1 << offset); + +done: + mutex_unlock(&gpio_lock); + return status; +} + +static void twl_free(struct gpio_chip *chip, unsigned offset) +{ + if (offset >= TWL4030_GPIO_MAX) { + twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1); + return; + } + + mutex_lock(&gpio_lock); + + gpio_usage_count &= ~BIT(offset); + + /* on last use, switch off GPIO module */ + if (!gpio_usage_count) + gpio_twl4030_write(REG_GPIO_CTRL, 0x0); + + mutex_unlock(&gpio_lock); +} + +static int twl_direction_in(struct gpio_chip *chip, unsigned offset) +{ + return (offset < TWL4030_GPIO_MAX) + ? twl4030_set_gpio_direction(offset, 1) + : -EINVAL; +} + +static int twl_get(struct gpio_chip *chip, unsigned offset) +{ + int status = 0; + + if (offset < TWL4030_GPIO_MAX) + status = twl4030_get_gpio_datain(offset); + else if (offset == TWL4030_GPIO_MAX) + status = cached_leden & LEDEN_LEDAON; + else + status = cached_leden & LEDEN_LEDBON; + return (status < 0) ? 0 : status; +} + +static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value) +{ + if (offset < TWL4030_GPIO_MAX) { + twl4030_set_gpio_dataout(offset, value); + return twl4030_set_gpio_direction(offset, 0); + } else { + twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value); + return 0; + } +} + +static void twl_set(struct gpio_chip *chip, unsigned offset, int value) +{ + if (offset < TWL4030_GPIO_MAX) + twl4030_set_gpio_dataout(offset, value); + else + twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value); +} + +static int twl_to_irq(struct gpio_chip *chip, unsigned offset) +{ + return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX)) + ? (twl4030_gpio_irq_base + offset) + : -EINVAL; +} + +static struct gpio_chip twl_gpiochip = { + .label = "twl4030", + .owner = THIS_MODULE, + .request = twl_request, + .free = twl_free, + .direction_input = twl_direction_in, + .get = twl_get, + .direction_output = twl_direction_out, + .set = twl_set, + .to_irq = twl_to_irq, + .can_sleep = 1, +}; + +/*----------------------------------------------------------------------*/ + +static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs) +{ + u8 message[6]; + unsigned i, gpio_bit; + + /* For most pins, a pulldown was enabled by default. + * We should have data that's specific to this board. + */ + for (gpio_bit = 1, i = 1; i < 6; i++) { + u8 bit_mask; + unsigned j; + + for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) { + if (ups & gpio_bit) + bit_mask |= 1 << (j + 1); + else if (downs & gpio_bit) + bit_mask |= 1 << (j + 0); + } + message[i] = bit_mask; + } + + return twl4030_i2c_write(TWL4030_MODULE_GPIO, message, + REG_GPIOPUPDCTR1, 5); +} + +static int gpio_twl4030_remove(struct platform_device *pdev); + +static int __devinit gpio_twl4030_probe(struct platform_device *pdev) +{ + struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data; + int ret; + + /* maybe setup IRQs */ + if (pdata->irq_base) { + if (is_module()) { + dev_err(&pdev->dev, + "can't dispatch IRQs from modules\n"); + goto no_irqs; + } + ret = twl4030_sih_setup(TWL4030_MODULE_GPIO); + if (ret < 0) + return ret; + WARN_ON(ret != pdata->irq_base); + twl4030_gpio_irq_base = ret; + } + +no_irqs: + /* + * NOTE: boards may waste power if they don't set pullups + * and pulldowns correctly ... default for non-ULPI pins is + * pulldown, and some other pins may have external pullups + * or pulldowns. Careful! + */ + ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns); + if (ret) + dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n", + pdata->pullups, pdata->pulldowns, + ret); + + twl_gpiochip.base = pdata->gpio_base; + twl_gpiochip.ngpio = TWL4030_GPIO_MAX; + twl_gpiochip.dev = &pdev->dev; + + /* NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE, + * is (still) clear if use_leds is set. + */ + if (pdata->use_leds) + twl_gpiochip.ngpio += 2; + + ret = gpiochip_add(&twl_gpiochip); + if (ret < 0) { + dev_err(&pdev->dev, + "could not register gpiochip, %d\n", + ret); + twl_gpiochip.ngpio = 0; + gpio_twl4030_remove(pdev); + } else if (pdata->setup) { + int status; + + status = pdata->setup(&pdev->dev, + pdata->gpio_base, TWL4030_GPIO_MAX); + if (status) + dev_dbg(&pdev->dev, "setup --> %d\n", status); + } + + return ret; +} + +static int __devexit gpio_twl4030_remove(struct platform_device *pdev) +{ + struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data; + int status; + + if (pdata->teardown) { + status = pdata->teardown(&pdev->dev, + pdata->gpio_base, TWL4030_GPIO_MAX); + if (status) { + dev_dbg(&pdev->dev, "teardown --> %d\n", status); + return status; + } + } + + status = gpiochip_remove(&twl_gpiochip); + if (status < 0) + return status; + + if (is_module()) + return 0; + + /* REVISIT no support yet for deregistering all the IRQs */ + WARN_ON(1); + return -EIO; +} + +/* Note: this hardware lives inside an I2C-based multi-function device. */ +MODULE_ALIAS("platform:twl4030_gpio"); + +static struct platform_driver gpio_twl4030_driver = { + .driver.name = "twl4030_gpio", + .driver.owner = THIS_MODULE, + .probe = gpio_twl4030_probe, + .remove = __devexit_p(gpio_twl4030_remove), +}; + +static int __init gpio_twl4030_init(void) +{ + return platform_driver_register(&gpio_twl4030_driver); +} +subsys_initcall(gpio_twl4030_init); + +static void __exit gpio_twl4030_exit(void) +{ + platform_driver_unregister(&gpio_twl4030_driver); +} +module_exit(gpio_twl4030_exit); + +MODULE_AUTHOR("Texas Instruments, Inc."); +MODULE_DESCRIPTION("GPIO interface for TWL4030"); +MODULE_LICENSE("GPL"); |
