diff options
| -rw-r--r-- | drivers/gpio/gpio-twl4030.c | 100 |
1 files changed, 65 insertions, 35 deletions
diff --git a/drivers/gpio/gpio-twl4030.c b/drivers/gpio/gpio-twl4030.c index 4643f9c..4d330e3 100644 --- a/drivers/gpio/gpio-twl4030.c +++ b/drivers/gpio/gpio-twl4030.c @@ -37,7 +37,6 @@ #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 @@ -64,14 +63,15 @@ /* Mask for GPIO registers when aggregated into a 32-bit integer */ #define GPIO_32_MASK 0x0003ffff -/* Data structures */ -static DEFINE_MUTEX(gpio_lock); - 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; }; /*----------------------------------------------------------------------*/ @@ -130,7 +130,7 @@ static inline int gpio_twl4030_read(u8 address) /*----------------------------------------------------------------------*/ -static u8 cached_leden; /* protected by gpio_lock */ +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 @@ -144,14 +144,12 @@ static void twl4030_led_set_value(int led, int value) if (led) mask <<= 1; - mutex_lock(&gpio_lock); if (value) cached_leden &= ~mask; else cached_leden |= mask; status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden, TWL4030_LED_LEDEN_REG); - mutex_unlock(&gpio_lock); } static int twl4030_set_gpio_direction(int gpio, int is_input) @@ -162,7 +160,6 @@ static int twl4030_set_gpio_direction(int gpio, int is_input) u8 base = REG_GPIODATADIR1 + d_bnk; int ret = 0; - mutex_lock(&gpio_lock); ret = gpio_twl4030_read(base); if (ret >= 0) { if (is_input) @@ -172,7 +169,6 @@ static int twl4030_set_gpio_direction(int gpio, int is_input) ret = gpio_twl4030_write(base, reg); } - mutex_unlock(&gpio_lock); return ret; } @@ -212,7 +208,7 @@ static int twl_request(struct gpio_chip *chip, unsigned offset) struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); int status = 0; - mutex_lock(&gpio_lock); + mutex_lock(&priv->mutex); /* Support the two LED outputs as output-only GPIOs. */ if (offset >= TWL4030_GPIO_MAX) { @@ -271,7 +267,7 @@ done: if (!status) priv->usage_count |= BIT(offset); - mutex_unlock(&gpio_lock); + mutex_unlock(&priv->mutex); return status; } @@ -279,64 +275,96 @@ 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); - return; + goto out; } - mutex_lock(&gpio_lock); - priv->usage_count &= ~BIT(offset); /* on last use, switch off GPIO module */ if (!priv->usage_count) gpio_twl4030_write(REG_GPIO_CTRL, 0x0); - mutex_unlock(&gpio_lock); +out: + mutex_unlock(&priv->mutex); } static int twl_direction_in(struct gpio_chip *chip, unsigned offset) { - return (offset < TWL4030_GPIO_MAX) - ? twl4030_set_gpio_direction(offset, 1) - : -EINVAL; + 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; + + 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; - if (!(priv->usage_count & BIT(offset))) - return -EPERM; + mutex_lock(&priv->mutex); + if (!(priv->usage_count & BIT(offset))) { + ret = -EPERM; + goto out; + } - if (offset < TWL4030_GPIO_MAX) - status = twl4030_get_gpio_datain(offset); - else if (offset == TWL4030_GPIO_MAX) - status = cached_leden & LEDEN_LEDAON; + if (priv->direction & BIT(offset)) + status = priv->out_state & BIT(offset); else - status = cached_leden & LEDEN_LEDBON; + status = twl4030_get_gpio_datain(offset); - return (status < 0) ? 0 : status; + ret = (status <= 0) ? 0 : 1; +out: + mutex_unlock(&priv->mutex); + return ret; } -static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value) +static void twl_set(struct gpio_chip *chip, unsigned offset, int value) { - if (offset < TWL4030_GPIO_MAX) { + struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); + + mutex_lock(&priv->mutex); + if (offset < TWL4030_GPIO_MAX) twl4030_set_gpio_dataout(offset, value); - return twl4030_set_gpio_direction(offset, 0); - } else { + else twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value); - return 0; - } + + if (value) + priv->out_state |= BIT(offset); + else + priv->out_state &= ~BIT(offset); + + mutex_unlock(&priv->mutex); } -static void twl_set(struct gpio_chip *chip, unsigned offset, int value) +static int twl_direction_out(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); + + priv->direction |= BIT(offset); + mutex_unlock(&priv->mutex); + + twl_set(chip, offset, value); + + return 0; } static int twl_to_irq(struct gpio_chip *chip, unsigned offset) @@ -469,6 +497,8 @@ no_irqs: 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); |
