diff options
Diffstat (limited to 'drivers/gpio/gpio-twl4030.c')
| -rw-r--r-- | drivers/gpio/gpio-twl4030.c | 631 |
1 files changed, 631 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-twl4030.c b/drivers/gpio/gpio-twl4030.c new file mode 100644 index 00000000000..3ebb1a5ff22 --- /dev/null +++ b/drivers/gpio/gpio-twl4030.c @@ -0,0 +1,631 @@ +/* + * 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/of.h> +#include <linux/irqdomain.h> + +#include <linux/i2c/twl.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. + */ + +/* 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 + +struct gpio_twl4030_priv { + struct gpio_chip gpio_chip; + struct mutex mutex; + int irq_base; + + /* Bitfields for state caching */ + unsigned int usage_count; + unsigned int direction; + unsigned int out_state; +}; + +/*----------------------------------------------------------------------*/ + +static inline struct gpio_twl4030_priv *to_gpio_twl4030(struct gpio_chip *chip) +{ + return container_of(chip, struct gpio_twl4030_priv, gpio_chip); +} + +/* + * To configure TWL4030 GPIO module registers + */ +static inline int gpio_twl4030_write(u8 address, u8 data) +{ + return twl_i2c_write_u8(TWL4030_MODULE_GPIO, data, address); +} + +/*----------------------------------------------------------------------*/ + +/* + * LED register offsets from TWL_MODULE_LED base + * PWMs A and B are dedicated to LEDs A and B, respectively. + */ + +#define TWL4030_LED_LEDEN_REG 0x00 +#define TWL4030_PWMAON_REG 0x01 +#define TWL4030_PWMAOFF_REG 0x02 +#define TWL4030_PWMBON_REG 0x03 +#define TWL4030_PWMBOFF_REG 0x04 + +/* 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 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 = twl_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address); + return (ret < 0) ? ret : data; +} + +/*----------------------------------------------------------------------*/ + +static u8 cached_leden; + +/* 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; + + if (led) + mask <<= 1; + + if (value) + cached_leden &= ~mask; + else + cached_leden |= mask; + + WARN_ON_ONCE(twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden, + TWL4030_LED_LEDEN_REG)); +} + +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; + + 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); + } + 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; + + 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) +{ + struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); + int status = 0; + + mutex_lock(&priv->mutex); + + /* 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 reg = TWL4030_PWMAON_REG; + + offset -= TWL4030_GPIO_MAX; + if (offset) { + ledclr_mask <<= 1; + reg = TWL4030_PWMBON_REG; + } + + /* initialize PWM to always-drive */ + /* Configure PWM OFF register first */ + status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg + 1); + if (status < 0) + goto done; + + /* Followed by PWM ON register */ + status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg); + if (status < 0) + goto done; + + /* init LED to not-driven (high) */ + status = twl_i2c_read_u8(TWL4030_MODULE_LED, &cached_leden, + TWL4030_LED_LEDEN_REG); + if (status < 0) + goto done; + cached_leden &= ~ledclr_mask; + status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden, + TWL4030_LED_LEDEN_REG); + if (status < 0) + goto done; + + status = 0; + goto done; + } + + /* on first use, turn GPIO module "on" */ + if (!priv->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 = dev_get_platdata(chip->dev); + if (pdata) + value |= pdata->mmc_cd & 0x03; + + status = gpio_twl4030_write(REG_GPIO_CTRL, value); + } + +done: + if (!status) + priv->usage_count |= BIT(offset); + + mutex_unlock(&priv->mutex); + return status; +} + +static void twl_free(struct gpio_chip *chip, unsigned offset) +{ + struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); + + mutex_lock(&priv->mutex); + if (offset >= TWL4030_GPIO_MAX) { + twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1); + goto out; + } + + priv->usage_count &= ~BIT(offset); + + /* on last use, switch off GPIO module */ + if (!priv->usage_count) + gpio_twl4030_write(REG_GPIO_CTRL, 0x0); + +out: + mutex_unlock(&priv->mutex); +} + +static int twl_direction_in(struct gpio_chip *chip, unsigned offset) +{ + struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); + int ret; + + mutex_lock(&priv->mutex); + if (offset < TWL4030_GPIO_MAX) + ret = twl4030_set_gpio_direction(offset, 1); + else + ret = -EINVAL; /* LED outputs can't be set as input */ + + if (!ret) + priv->direction &= ~BIT(offset); + + mutex_unlock(&priv->mutex); + + return ret; +} + +static int twl_get(struct gpio_chip *chip, unsigned offset) +{ + struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); + int ret; + int status = 0; + + mutex_lock(&priv->mutex); + if (!(priv->usage_count & BIT(offset))) { + ret = -EPERM; + goto out; + } + + if (priv->direction & BIT(offset)) + status = priv->out_state & BIT(offset); + else + status = twl4030_get_gpio_datain(offset); + + ret = (status <= 0) ? 0 : 1; +out: + mutex_unlock(&priv->mutex); + return ret; +} + +static void twl_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); + + mutex_lock(&priv->mutex); + if (offset < TWL4030_GPIO_MAX) + twl4030_set_gpio_dataout(offset, value); + else + twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value); + + if (value) + priv->out_state |= BIT(offset); + else + priv->out_state &= ~BIT(offset); + + mutex_unlock(&priv->mutex); +} + +static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value) +{ + struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); + int ret = 0; + + mutex_lock(&priv->mutex); + if (offset < TWL4030_GPIO_MAX) { + ret = twl4030_set_gpio_direction(offset, 0); + if (ret) { + mutex_unlock(&priv->mutex); + return ret; + } + } + + /* + * LED gpios i.e. offset >= TWL4030_GPIO_MAX are always output + */ + + priv->direction |= BIT(offset); + mutex_unlock(&priv->mutex); + + twl_set(chip, offset, value); + + return ret; +} + +static int twl_to_irq(struct gpio_chip *chip, unsigned offset) +{ + struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); + + return (priv->irq_base && (offset < TWL4030_GPIO_MAX)) + ? (priv->irq_base + offset) + : -EINVAL; +} + +static struct gpio_chip template_chip = { + .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 = true, +}; + +/*----------------------------------------------------------------------*/ + +static int gpio_twl4030_pulls(u32 ups, u32 downs) +{ + u8 message[5]; + 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 = 0; i < 5; 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 twl_i2c_write(TWL4030_MODULE_GPIO, message, + REG_GPIOPUPDCTR1, 5); +} + +static int gpio_twl4030_debounce(u32 debounce, u8 mmc_cd) +{ + u8 message[3]; + + /* 30 msec of debouncing is always used for MMC card detect, + * and is optional for everything else. + */ + message[0] = (debounce & 0xff) | (mmc_cd & 0x03); + debounce >>= 8; + message[1] = (debounce & 0xff); + debounce >>= 8; + message[2] = (debounce & 0x03); + + return twl_i2c_write(TWL4030_MODULE_GPIO, message, + REG_GPIO_DEBEN1, 3); +} + +static int gpio_twl4030_remove(struct platform_device *pdev); + +static struct twl4030_gpio_platform_data *of_gpio_twl4030(struct device *dev, + struct twl4030_gpio_platform_data *pdata) +{ + struct twl4030_gpio_platform_data *omap_twl_info; + + omap_twl_info = devm_kzalloc(dev, sizeof(*omap_twl_info), GFP_KERNEL); + if (!omap_twl_info) + return NULL; + + if (pdata) + *omap_twl_info = *pdata; + + omap_twl_info->use_leds = of_property_read_bool(dev->of_node, + "ti,use-leds"); + + of_property_read_u32(dev->of_node, "ti,debounce", + &omap_twl_info->debounce); + of_property_read_u32(dev->of_node, "ti,mmc-cd", + (u32 *)&omap_twl_info->mmc_cd); + of_property_read_u32(dev->of_node, "ti,pullups", + &omap_twl_info->pullups); + of_property_read_u32(dev->of_node, "ti,pulldowns", + &omap_twl_info->pulldowns); + + return omap_twl_info; +} + +static int gpio_twl4030_probe(struct platform_device *pdev) +{ + struct twl4030_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); + struct device_node *node = pdev->dev.of_node; + struct gpio_twl4030_priv *priv; + int ret, irq_base; + + priv = devm_kzalloc(&pdev->dev, sizeof(struct gpio_twl4030_priv), + GFP_KERNEL); + if (!priv) + return -ENOMEM; + + /* maybe setup IRQs */ + if (is_module()) { + dev_err(&pdev->dev, "can't dispatch IRQs from modules\n"); + goto no_irqs; + } + + irq_base = irq_alloc_descs(-1, 0, TWL4030_GPIO_MAX, 0); + if (irq_base < 0) { + dev_err(&pdev->dev, "Failed to alloc irq_descs\n"); + return irq_base; + } + + irq_domain_add_legacy(node, TWL4030_GPIO_MAX, irq_base, 0, + &irq_domain_simple_ops, NULL); + + ret = twl4030_sih_setup(&pdev->dev, TWL4030_MODULE_GPIO, irq_base); + if (ret < 0) + return ret; + + priv->irq_base = irq_base; + +no_irqs: + priv->gpio_chip = template_chip; + priv->gpio_chip.base = -1; + priv->gpio_chip.ngpio = TWL4030_GPIO_MAX; + priv->gpio_chip.dev = &pdev->dev; + + mutex_init(&priv->mutex); + + if (node) + pdata = of_gpio_twl4030(&pdev->dev, pdata); + + if (pdata == NULL) { + dev_err(&pdev->dev, "Platform data is missing\n"); + return -ENXIO; + } + + /* + * 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); + + /* + * NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE, + * is (still) clear if use_leds is set. + */ + if (pdata->use_leds) + priv->gpio_chip.ngpio += 2; + + ret = gpiochip_add(&priv->gpio_chip); + if (ret < 0) { + dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret); + priv->gpio_chip.ngpio = 0; + gpio_twl4030_remove(pdev); + goto out; + } + + platform_set_drvdata(pdev, priv); + + if (pdata && pdata->setup) { + int status; + + status = pdata->setup(&pdev->dev, priv->gpio_chip.base, + TWL4030_GPIO_MAX); + if (status) + dev_dbg(&pdev->dev, "setup --> %d\n", status); + } + +out: + return ret; +} + +/* Cannot use as gpio_twl4030_probe() calls us */ +static int gpio_twl4030_remove(struct platform_device *pdev) +{ + struct twl4030_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); + struct gpio_twl4030_priv *priv = platform_get_drvdata(pdev); + int status; + + if (pdata && pdata->teardown) { + status = pdata->teardown(&pdev->dev, priv->gpio_chip.base, + TWL4030_GPIO_MAX); + if (status) { + dev_dbg(&pdev->dev, "teardown --> %d\n", status); + return status; + } + } + + status = gpiochip_remove(&priv->gpio_chip); + if (status < 0) + return status; + + if (is_module()) + return 0; + + /* REVISIT no support yet for deregistering all the IRQs */ + WARN_ON(1); + return -EIO; +} + +static const struct of_device_id twl_gpio_match[] = { + { .compatible = "ti,twl4030-gpio", }, + { }, +}; +MODULE_DEVICE_TABLE(of, twl_gpio_match); + +/* 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", + .owner = THIS_MODULE, + .of_match_table = twl_gpio_match, + }, + .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"); |