diff options
Diffstat (limited to 'drivers/leds/leds-ti-lmu-common.c')
| -rw-r--r-- | drivers/leds/leds-ti-lmu-common.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/drivers/leds/leds-ti-lmu-common.c b/drivers/leds/leds-ti-lmu-common.c new file mode 100644 index 000000000000..adc7293004f1 --- /dev/null +++ b/drivers/leds/leds-ti-lmu-common.c @@ -0,0 +1,156 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright 2015 Texas Instruments +// Copyright 2018 Sebastian Reichel +// Copyright 2018 Pavel Machek <pavel@ucw.cz> +// TI LMU LED common framework, based on previous work from +// Milo Kim <milo.kim@ti.com> + +#include <linux/bitops.h> +#include <linux/err.h> +#include <linux/of_device.h> + +#include <linux/leds-ti-lmu-common.h> + +const static int ramp_table[16] = {2048, 262000, 524000, 1049000, 2090000, + 4194000, 8389000, 16780000, 33550000, 41940000, + 50330000, 58720000, 67110000, 83880000, + 100660000, 117440000}; + +static int ti_lmu_common_update_brightness(struct ti_lmu_bank *lmu_bank, + int brightness) +{ + struct regmap *regmap = lmu_bank->regmap; + u8 reg, val; + int ret; + + /* + * Brightness register update + * + * 11 bit dimming: update LSB bits and write MSB byte. + * MSB brightness should be shifted. + * 8 bit dimming: write MSB byte. + */ + if (lmu_bank->max_brightness == MAX_BRIGHTNESS_11BIT) { + reg = lmu_bank->lsb_brightness_reg; + ret = regmap_update_bits(regmap, reg, + LMU_11BIT_LSB_MASK, + brightness); + if (ret) + return ret; + + val = brightness >> LMU_11BIT_MSB_SHIFT; + } else { + val = brightness; + } + + reg = lmu_bank->msb_brightness_reg; + + return regmap_write(regmap, reg, val); +} + +int ti_lmu_common_set_brightness(struct ti_lmu_bank *lmu_bank, int brightness) +{ + return ti_lmu_common_update_brightness(lmu_bank, brightness); +} +EXPORT_SYMBOL(ti_lmu_common_set_brightness); + +static int ti_lmu_common_convert_ramp_to_index(unsigned int usec) +{ + int size = ARRAY_SIZE(ramp_table); + int i; + + if (usec <= ramp_table[0]) + return 0; + + if (usec > ramp_table[size - 1]) + return size - 1; + + for (i = 1; i < size; i++) { + if (usec == ramp_table[i]) + return i; + + /* Find an approximate index by looking up the table */ + if (usec > ramp_table[i - 1] && usec < ramp_table[i]) { + if (usec - ramp_table[i - 1] < ramp_table[i] - usec) + return i - 1; + else + return i; + } + } + + return -EINVAL; +} + +int ti_lmu_common_set_ramp(struct ti_lmu_bank *lmu_bank) +{ + struct regmap *regmap = lmu_bank->regmap; + u8 ramp, ramp_up, ramp_down; + + if (lmu_bank->ramp_up_usec == 0 && lmu_bank->ramp_down_usec == 0) { + ramp_up = 0; + ramp_down = 0; + } else { + ramp_up = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_up_usec); + ramp_down = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_down_usec); + } + + if (ramp_up < 0 || ramp_down < 0) + return -EINVAL; + + ramp = (ramp_up << 4) | ramp_down; + + return regmap_write(regmap, lmu_bank->runtime_ramp_reg, ramp); + +} +EXPORT_SYMBOL(ti_lmu_common_set_ramp); + +int ti_lmu_common_get_ramp_params(struct device *dev, + struct fwnode_handle *child, + struct ti_lmu_bank *lmu_data) +{ + int ret; + + ret = fwnode_property_read_u32(child, "ramp-up-us", + &lmu_data->ramp_up_usec); + if (ret) + dev_warn(dev, "ramp-up-us property missing\n"); + + + ret = fwnode_property_read_u32(child, "ramp-down-us", + &lmu_data->ramp_down_usec); + if (ret) + dev_warn(dev, "ramp-down-us property missing\n"); + + return 0; +} +EXPORT_SYMBOL(ti_lmu_common_get_ramp_params); + +int ti_lmu_common_get_brt_res(struct device *dev, struct fwnode_handle *child, + struct ti_lmu_bank *lmu_data) +{ + int ret; + + ret = device_property_read_u32(dev, "ti,brightness-resolution", + &lmu_data->max_brightness); + if (ret) + ret = fwnode_property_read_u32(child, + "ti,brightness-resolution", + &lmu_data->max_brightness); + if (lmu_data->max_brightness <= 0) { + lmu_data->max_brightness = MAX_BRIGHTNESS_8BIT; + return ret; + } + + if (lmu_data->max_brightness > MAX_BRIGHTNESS_11BIT) + lmu_data->max_brightness = MAX_BRIGHTNESS_11BIT; + + + return 0; +} +EXPORT_SYMBOL(ti_lmu_common_get_brt_res); + +MODULE_DESCRIPTION("TI LMU common LED framework"); +MODULE_AUTHOR("Sebastian Reichel"); +MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("ti-lmu-led-common"); |