/* * 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; } /*----------------------------------------------------------------------*/ 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 __devinit gpio_twl4030_debounce(u32 debounce, u8 mmc_cd) { u8 message[4]; /* 30 msec of debouncing is always used for MMC card detect, * and is optional for everything else. */ message[1] = (debounce & 0xff) | (mmc_cd & 0x03); debounce >>= 8; message[2] = (debounce & 0xff); debounce >>= 8; message[3] = (debounce & 0x03); return twl4030_i2c_write(TWL4030_MODULE_GPIO, message, REG_GPIO_DEBEN1, 3); } 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); ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd); if (ret) dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n", pdata->debounce, pdata->mmc_cd, 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; } /* Cannot use __devexit as gpio_twl4030_probe() calls us */ static int 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 = 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");