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// 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");
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