From: David Brownell Date: Mon, 13 Oct 2008 20:04:16 +0000 (-0700) Subject: twl4030-gpio supports LED signals X-Git-Tag: v2.6.27-omap1~31 X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?p=linux-2.6-omap-h63xx.git;a=commitdiff_plain;h=4ade1742fb39a43a8b29055d499591c7cace4aa4 twl4030-gpio supports LED signals Expose the two TWL4030 LED signals as output-only GPIOs. Boards need to explicitly ask that this be done, to help avoid conflicts on boards using these same pins to hook up to a vibrator motor. Note that these are high drive open drain signals; LEDA is rated for up to 160 mA (!), LEDB up to 60 mA. Boards using one of these signals to drive a bank of LCD backlight LEDs would probably want to access the dedicated PWMs for brightness control, too; easy to add such support later. Example: Beagle has one real LED here (PWM not necessary), and one GPIO controlling VBUS output over EHCI (PWM not wanted). Signed-off-by: David Brownell Signed-off-by: Tony Lindgren --- diff --git a/drivers/gpio/twl4030-gpio.c b/drivers/gpio/twl4030-gpio.c index 4c164298095..e4974364cd9 100644 --- a/drivers/gpio/twl4030-gpio.c +++ b/drivers/gpio/twl4030-gpio.c @@ -85,6 +85,32 @@ 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 */ @@ -97,6 +123,32 @@ static inline int gpio_twl4030_read(u8 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; @@ -226,6 +278,44 @@ static int twl_request(struct gpio_chip *chip, unsigned offset) 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) status = gpio_twl4030_write(REG_GPIO_CTRL, @@ -241,6 +331,11 @@ done: 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); @@ -254,30 +349,46 @@ static void twl_free(struct gpio_chip *chip, unsigned offset) static int twl_direction_in(struct gpio_chip *chip, unsigned offset) { - return twl4030_set_gpio_direction(offset, 1); + return (offset < TWL4030_GPIO_MAX) + ? twl4030_set_gpio_direction(offset, 1) + : -EINVAL; } static int twl_get(struct gpio_chip *chip, unsigned offset) { - int status = twl4030_get_gpio_datain(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) { - twl4030_set_gpio_dataout(offset, value); - return twl4030_set_gpio_direction(offset, 0); + 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) { - twl4030_set_gpio_dataout(offset, 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 + return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX)) ? (twl4030_gpio_irq_base + offset) : -EINVAL; } @@ -360,6 +471,12 @@ no_irqs: 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, diff --git a/include/linux/i2c/twl4030.h b/include/linux/i2c/twl4030.h index aab2ee6779f..03b948287c9 100644 --- a/include/linux/i2c/twl4030.h +++ b/include/linux/i2c/twl4030.h @@ -228,6 +228,9 @@ struct twl4030_gpio_platform_data { int gpio_base; unsigned irq_base, irq_end; + /* package the two LED signals as output-only GPIOs? */ + bool use_leds; + /* For gpio-N, bit (1 << N) in "pullups" is set if that pullup * should be enabled. Else, if that bit is set in "pulldowns", * that pulldown is enabled. Don't waste power by letting any