cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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leds-ti-lmu-common.c (3860B)

      1// SPDX-License-Identifier: GPL-2.0
      2// Copyright 2015 Texas Instruments
      3// Copyright 2018 Sebastian Reichel
      4// Copyright 2018 Pavel Machek <pavel@ucw.cz>
      5// TI LMU LED common framework, based on previous work from
      6// Milo Kim <milo.kim@ti.com>
      7
      8#include <linux/bitops.h>
      9#include <linux/err.h>
     10#include <linux/of_device.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 update
     28	 *
     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			else
     77				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");