// 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> static const unsigned 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 unsigned 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 0; } 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); } 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");