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1// SPDX-License-Identifier: GPL-2.02// Copyright 2015 Texas Instruments3// Copyright 2018 Sebastian Reichel4// Copyright 2018 Pavel Machek <pavel@ucw.cz>5// TI LMU LED common framework, based on previous work from6// Milo Kim <milo.kim@ti.com>7 8#include <linux/bitops.h>9#include <linux/err.h>10#include <linux/property.h>11 12#include <linux/leds-ti-lmu-common.h>13 14static const unsigned int ramp_table[16] = {2048, 262000, 524000, 1049000,15 2090000, 4194000, 8389000, 16780000, 33550000,16 41940000, 50330000, 58720000, 67110000,17 83880000, 100660000, 117440000};18 19static int ti_lmu_common_update_brightness(struct ti_lmu_bank *lmu_bank,20 int brightness)21{22 struct regmap *regmap = lmu_bank->regmap;23 u8 reg, val;24 int ret;25 26 /*27 * Brightness register update28 *29 * 11 bit dimming: update LSB bits and write MSB byte.30 * MSB brightness should be shifted.31 * 8 bit dimming: write MSB byte.32 */33 if (lmu_bank->max_brightness == MAX_BRIGHTNESS_11BIT) {34 reg = lmu_bank->lsb_brightness_reg;35 ret = regmap_update_bits(regmap, reg,36 LMU_11BIT_LSB_MASK,37 brightness);38 if (ret)39 return ret;40 41 val = brightness >> LMU_11BIT_MSB_SHIFT;42 } else {43 val = brightness;44 }45 46 reg = lmu_bank->msb_brightness_reg;47 48 return regmap_write(regmap, reg, val);49}50 51int ti_lmu_common_set_brightness(struct ti_lmu_bank *lmu_bank, int brightness)52{53 return ti_lmu_common_update_brightness(lmu_bank, brightness);54}55EXPORT_SYMBOL(ti_lmu_common_set_brightness);56 57static unsigned int ti_lmu_common_convert_ramp_to_index(unsigned int usec)58{59 int size = ARRAY_SIZE(ramp_table);60 int i;61 62 if (usec <= ramp_table[0])63 return 0;64 65 if (usec > ramp_table[size - 1])66 return size - 1;67 68 for (i = 1; i < size; i++) {69 if (usec == ramp_table[i])70 return i;71 72 /* Find an approximate index by looking up the table */73 if (usec > ramp_table[i - 1] && usec < ramp_table[i]) {74 if (usec - ramp_table[i - 1] < ramp_table[i] - usec)75 return i - 1;76 else77 return i;78 }79 }80 81 return 0;82}83 84int ti_lmu_common_set_ramp(struct ti_lmu_bank *lmu_bank)85{86 struct regmap *regmap = lmu_bank->regmap;87 u8 ramp, ramp_up, ramp_down;88 89 if (lmu_bank->ramp_up_usec == 0 && lmu_bank->ramp_down_usec == 0) {90 ramp_up = 0;91 ramp_down = 0;92 } else {93 ramp_up = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_up_usec);94 ramp_down = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_down_usec);95 }96 97 ramp = (ramp_up << 4) | ramp_down;98 99 return regmap_write(regmap, lmu_bank->runtime_ramp_reg, ramp);100 101}102EXPORT_SYMBOL(ti_lmu_common_set_ramp);103 104int ti_lmu_common_get_ramp_params(struct device *dev,105 struct fwnode_handle *child,106 struct ti_lmu_bank *lmu_data)107{108 int ret;109 110 ret = fwnode_property_read_u32(child, "ramp-up-us",111 &lmu_data->ramp_up_usec);112 if (ret)113 dev_warn(dev, "ramp-up-us property missing\n");114 115 116 ret = fwnode_property_read_u32(child, "ramp-down-us",117 &lmu_data->ramp_down_usec);118 if (ret)119 dev_warn(dev, "ramp-down-us property missing\n");120 121 return 0;122}123EXPORT_SYMBOL(ti_lmu_common_get_ramp_params);124 125int ti_lmu_common_get_brt_res(struct device *dev, struct fwnode_handle *child,126 struct ti_lmu_bank *lmu_data)127{128 int ret;129 130 ret = device_property_read_u32(dev, "ti,brightness-resolution",131 &lmu_data->max_brightness);132 if (ret)133 ret = fwnode_property_read_u32(child,134 "ti,brightness-resolution",135 &lmu_data->max_brightness);136 if (lmu_data->max_brightness <= 0) {137 lmu_data->max_brightness = MAX_BRIGHTNESS_8BIT;138 return ret;139 }140 141 if (lmu_data->max_brightness > MAX_BRIGHTNESS_11BIT)142 lmu_data->max_brightness = MAX_BRIGHTNESS_11BIT;143 144 145 return 0;146}147EXPORT_SYMBOL(ti_lmu_common_get_brt_res);148 149MODULE_DESCRIPTION("TI LMU common LED framework");150MODULE_AUTHOR("Sebastian Reichel");151MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");152MODULE_LICENSE("GPL v2");153MODULE_ALIAS("ti-lmu-led-common");154