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