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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tosa_bl.c (3824B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  LCD / Backlight control code for Sharp SL-6000x (tosa)
      4 *
      5 *  Copyright (c) 2005		Dirk Opfer
      6 *  Copyright (c) 2007,2008	Dmitry Baryshkov
      7 */
      8
      9#include <linux/kernel.h>
     10#include <linux/module.h>
     11#include <linux/device.h>
     12#include <linux/spi/spi.h>
     13#include <linux/i2c.h>
     14#include <linux/gpio/consumer.h>
     15#include <linux/fb.h>
     16#include <linux/backlight.h>
     17#include <linux/slab.h>
     18
     19#include <asm/mach/sharpsl_param.h>
     20
     21#include "tosa_bl.h"
     22
     23#define COMADJ_DEFAULT	97
     24
     25#define DAC_CH1		0
     26#define DAC_CH2		1
     27
     28struct tosa_bl_data {
     29	struct i2c_client *i2c;
     30	struct backlight_device *bl;
     31	struct gpio_desc *gpio;
     32
     33	int comadj;
     34};
     35
     36static void tosa_bl_set_backlight(struct tosa_bl_data *data, int brightness)
     37{
     38	struct spi_device *spi = dev_get_platdata(&data->i2c->dev);
     39
     40	i2c_smbus_write_byte_data(data->i2c, DAC_CH1, data->comadj);
     41
     42	/* SetBacklightDuty */
     43	i2c_smbus_write_byte_data(data->i2c, DAC_CH2, (u8)(brightness & 0xff));
     44
     45	/* SetBacklightVR */
     46	gpiod_set_value(data->gpio, brightness & 0x100);
     47
     48	tosa_bl_enable(spi, brightness);
     49}
     50
     51static int tosa_bl_update_status(struct backlight_device *dev)
     52{
     53	struct backlight_properties *props = &dev->props;
     54	struct tosa_bl_data *data = bl_get_data(dev);
     55	int power = max(props->power, props->fb_blank);
     56	int brightness = props->brightness;
     57
     58	if (power)
     59		brightness = 0;
     60
     61	tosa_bl_set_backlight(data, brightness);
     62
     63	return 0;
     64}
     65
     66static int tosa_bl_get_brightness(struct backlight_device *dev)
     67{
     68	struct backlight_properties *props = &dev->props;
     69
     70	return props->brightness;
     71}
     72
     73static const struct backlight_ops bl_ops = {
     74	.get_brightness		= tosa_bl_get_brightness,
     75	.update_status		= tosa_bl_update_status,
     76};
     77
     78static int tosa_bl_probe(struct i2c_client *client,
     79		const struct i2c_device_id *id)
     80{
     81	struct backlight_properties props;
     82	struct tosa_bl_data *data;
     83	int ret = 0;
     84
     85	data = devm_kzalloc(&client->dev, sizeof(struct tosa_bl_data),
     86				GFP_KERNEL);
     87	if (!data)
     88		return -ENOMEM;
     89
     90	data->comadj = sharpsl_param.comadj == -1 ? COMADJ_DEFAULT : sharpsl_param.comadj;
     91	data->gpio = devm_gpiod_get(&client->dev, "backlight", GPIOD_OUT_LOW);
     92	ret = PTR_ERR_OR_ZERO(data->gpio);
     93	if (ret) {
     94		dev_dbg(&data->bl->dev, "Unable to request gpio!\n");
     95		return ret;
     96	}
     97
     98	i2c_set_clientdata(client, data);
     99	data->i2c = client;
    100
    101	memset(&props, 0, sizeof(struct backlight_properties));
    102	props.type = BACKLIGHT_RAW;
    103	props.max_brightness = 512 - 1;
    104	data->bl = devm_backlight_device_register(&client->dev, "tosa-bl",
    105						&client->dev, data, &bl_ops,
    106						&props);
    107	if (IS_ERR(data->bl)) {
    108		ret = PTR_ERR(data->bl);
    109		goto err_reg;
    110	}
    111
    112	data->bl->props.brightness = 69;
    113	data->bl->props.power = FB_BLANK_UNBLANK;
    114
    115	backlight_update_status(data->bl);
    116
    117	return 0;
    118
    119err_reg:
    120	data->bl = NULL;
    121	return ret;
    122}
    123
    124static int tosa_bl_remove(struct i2c_client *client)
    125{
    126	struct tosa_bl_data *data = i2c_get_clientdata(client);
    127
    128	data->bl = NULL;
    129	return 0;
    130}
    131
    132#ifdef CONFIG_PM_SLEEP
    133static int tosa_bl_suspend(struct device *dev)
    134{
    135	struct tosa_bl_data *data = dev_get_drvdata(dev);
    136
    137	tosa_bl_set_backlight(data, 0);
    138
    139	return 0;
    140}
    141
    142static int tosa_bl_resume(struct device *dev)
    143{
    144	struct tosa_bl_data *data = dev_get_drvdata(dev);
    145
    146	backlight_update_status(data->bl);
    147	return 0;
    148}
    149#endif
    150
    151static SIMPLE_DEV_PM_OPS(tosa_bl_pm_ops, tosa_bl_suspend, tosa_bl_resume);
    152
    153static const struct i2c_device_id tosa_bl_id[] = {
    154	{ "tosa-bl", 0 },
    155	{ },
    156};
    157MODULE_DEVICE_TABLE(i2c, tosa_bl_id);
    158
    159static struct i2c_driver tosa_bl_driver = {
    160	.driver = {
    161		.name		= "tosa-bl",
    162		.pm		= &tosa_bl_pm_ops,
    163	},
    164	.probe		= tosa_bl_probe,
    165	.remove		= tosa_bl_remove,
    166	.id_table	= tosa_bl_id,
    167};
    168
    169module_i2c_driver(tosa_bl_driver);
    170
    171MODULE_AUTHOR("Dmitry Baryshkov");
    172MODULE_LICENSE("GPL v2");
    173MODULE_DESCRIPTION("LCD/Backlight control for Sharp SL-6000 PDA");
    174