diff options
Diffstat (limited to 'drivers/gpio/twl4030-pwm.c')
| -rw-r--r-- | drivers/gpio/twl4030-pwm.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/drivers/gpio/twl4030-pwm.c b/drivers/gpio/twl4030-pwm.c new file mode 100644 index 0000000000..dfbb7f5b59 --- /dev/null +++ b/drivers/gpio/twl4030-pwm.c @@ -0,0 +1,126 @@ +#include <common.h> +#include <twl4030.h> + +/* INTRB register offsets (TWL4030_CHIP_INTBR) */ +#define TWL_INTBR_PMBR1 0x92 +#define TWL_INTBR_GPBR1 0x91 + +/*PWM0 register offsets (TWL4030_CHIP_PWM0) */ +#define TWL_LED_PWMON 0xf8 +#define TWL_LED_PWMOFF 0xf9 + +#if 0 +#define PWM_PRINT(fmt, args...) printf(fmt, ## args) +#else +#define PWM_PRINT(fmt, args...) +#endif + +int twl4030_set_pwm0(int level, int max_brightness) +{ + u8 mux_pwm, enb_pwm; + unsigned char c; + int status; + + PWM_PRINT("%s: level %d\n", __FUNCTION__, level); + if (level > max_brightness) + return -1; + + twl4030_i2c_read_u8(TWL4030_CHIP_INTBR, &mux_pwm, TWL_INTBR_PMBR1); + twl4030_i2c_read_u8(TWL4030_CHIP_INTBR, &enb_pwm, TWL_INTBR_GPBR1); + + PWM_PRINT("%s: enb_pwm %02x mux_pwm %02x\n", __FUNCTION__, enb_pwm, mux_pwm); + + if (level == 0) { + /* disable pwm0 output and clock */ + enb_pwm &= ~0x05; + /* change pwm0 pin to gpio pin */ + mux_pwm &= ~0x0c; + + PWM_PRINT("%s: disable enb_pwm %02x mux_pwm %02x\n", __FUNCTION__, enb_pwm, mux_pwm); + + status = twl4030_i2c_write_u8(TWL4030_CHIP_INTBR, + enb_pwm, TWL_INTBR_GPBR1); + if (status) { + printf("%s:%d status %d\n", __FUNCTION__, __LINE__, status); + return -2; + } + status = twl4030_i2c_write_u8(TWL4030_CHIP_INTBR, + mux_pwm, TWL_INTBR_PMBR1); + if (status) { + printf("%s:%d status %d\n", __FUNCTION__, __LINE__, status); + return -3; + } +#if 0 + PWM_PRINT("%s: turn off GPIO_%d as backlight!\n", __FUNCTION__, omap3logic_dss_lcd_data.lcd_gpio_backlight); + /* Turn off the backlight! */ + gpio_set_value(omap3logic_dss_lcd_data.lcd_gpio_backlight, 0); +#endif + return 0; + } + + if (((enb_pwm & 0x5) != 0x5) || ((mux_pwm & 0x0c) != 0x4)) { + /* change gpio pin to pwm0 pin */ + mux_pwm = (mux_pwm & ~0xc) | 0x04; + /* enable pwm0 output and clock*/ + enb_pwm = (enb_pwm & ~0x5) | 0x05; + + PWM_PRINT("%s: enable enb_pwm %02x mux_pwm %02x\n", __FUNCTION__, enb_pwm, mux_pwm); + status = twl4030_i2c_write_u8(TWL4030_CHIP_INTBR, + mux_pwm, TWL_INTBR_PMBR1); + if (status) { + printf("%s:%d status %d\n", __FUNCTION__, __LINE__, status); + return -4; + } + status = twl4030_i2c_write_u8(TWL4030_CHIP_INTBR, + enb_pwm, TWL_INTBR_GPBR1); + if (status) { + printf("%s:%d status %d\n", __FUNCTION__, __LINE__, status); + return -5; + } +#if 0 + PWM_PRINT("%s: turn on GPIO_%d as backlight!\n", __FUNCTION__, omap3logic_dss_lcd_data.lcd_gpio_backlight); + /* Turn on the backlight! */ + gpio_set_value(omap3logic_dss_lcd_data.lcd_gpio_backlight, 1); +#endif + } + + /* 255 -> 1, 1 -> 126 */ + c = (max_brightness * 126 + (1 - 126) * level) / (max_brightness - 1); + + PWM_PRINT("%s: c %d (%d%% on)\n", __FUNCTION__, c, (((max_brightness+1)-c) * 100)/(max_brightness+1)); + status = twl4030_i2c_write_u8(TWL4030_CHIP_PWM0, 0x7F, TWL_LED_PWMOFF); + if (status) { + PWM_PRINT("%s:%d status %d\n", __FUNCTION__, __LINE__, status); + return -6; + } + status = twl4030_i2c_write_u8(TWL4030_CHIP_PWM0, c, TWL_LED_PWMON); + if (status) { + PWM_PRINT("%s:%d status %d\n", __FUNCTION__, __LINE__, status); + return -7; + } + return 0; +} + +void twl4030_dump_pwm0(void) +{ + int result; + u8 mux_pwm, enb_pwm; + u8 off_period, on_period; + + result = twl4030_i2c_read_u8(TWL4030_CHIP_INTBR, &mux_pwm, + TWL_INTBR_PMBR1); + result |= twl4030_i2c_read_u8(TWL4030_CHIP_INTBR, &enb_pwm, + TWL_INTBR_GPBR1); + + result |= twl4030_i2c_read_u8(TWL4030_CHIP_PWM0, &off_period, + TWL_LED_PWMOFF); + result |=twl4030_i2c_read_u8(TWL4030_CHIP_PWM0, &on_period, + TWL_LED_PWMON); + + if (result) { + printf("%s: failed to read TWL regitsters; result %d\n", __FUNCTION__, result); + return; + } + printf("%s: mux_pwm %02x enb_pwm %02x off_period %02x on_period %02x\n", + __FUNCTION__, mux_pwm, enb_pwm, off_period, on_period); +} |