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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bd6107.c (5676B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * ROHM Semiconductor BD6107 LED Driver
      4 *
      5 * Copyright (C) 2013 Ideas on board SPRL
      6 *
      7 * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
      8 */
      9
     10#include <linux/backlight.h>
     11#include <linux/delay.h>
     12#include <linux/err.h>
     13#include <linux/fb.h>
     14#include <linux/gpio/consumer.h>
     15#include <linux/i2c.h>
     16#include <linux/module.h>
     17#include <linux/platform_data/bd6107.h>
     18#include <linux/slab.h>
     19
     20#define BD6107_PSCNT1				0x00
     21#define BD6107_PSCNT1_PSCNTREG2			(1 << 2)
     22#define BD6107_PSCNT1_PSCNTREG1			(1 << 0)
     23#define BD6107_REGVSET				0x02
     24#define BD6107_REGVSET_REG1VSET_2_85V		(1 << 2)
     25#define BD6107_REGVSET_REG1VSET_2_80V		(0 << 2)
     26#define BD6107_LEDCNT1				0x03
     27#define BD6107_LEDCNT1_LEDONOFF2		(1 << 1)
     28#define BD6107_LEDCNT1_LEDONOFF1		(1 << 0)
     29#define BD6107_PORTSEL				0x04
     30#define BD6107_PORTSEL_LEDM(n)			(1 << (n))
     31#define BD6107_RGB1CNT1				0x05
     32#define BD6107_RGB1CNT2				0x06
     33#define BD6107_RGB1CNT3				0x07
     34#define BD6107_RGB1CNT4				0x08
     35#define BD6107_RGB1CNT5				0x09
     36#define BD6107_RGB1FLM				0x0a
     37#define BD6107_RGB2CNT1				0x0b
     38#define BD6107_RGB2CNT2				0x0c
     39#define BD6107_RGB2CNT3				0x0d
     40#define BD6107_RGB2CNT4				0x0e
     41#define BD6107_RGB2CNT5				0x0f
     42#define BD6107_RGB2FLM				0x10
     43#define BD6107_PSCONT3				0x11
     44#define BD6107_SMMONCNT				0x12
     45#define BD6107_DCDCCNT				0x13
     46#define BD6107_IOSEL				0x14
     47#define BD6107_OUT1				0x15
     48#define BD6107_OUT2				0x16
     49#define BD6107_MASK1				0x17
     50#define BD6107_MASK2				0x18
     51#define BD6107_FACTOR1				0x19
     52#define BD6107_FACTOR2				0x1a
     53#define BD6107_CLRFACT1				0x1b
     54#define BD6107_CLRFACT2				0x1c
     55#define BD6107_STATE1				0x1d
     56#define BD6107_LSIVER				0x1e
     57#define BD6107_GRPSEL				0x1f
     58#define BD6107_LEDCNT2				0x20
     59#define BD6107_LEDCNT3				0x21
     60#define BD6107_MCURRENT				0x22
     61#define BD6107_MAINCNT1				0x23
     62#define BD6107_MAINCNT2				0x24
     63#define BD6107_SLOPECNT				0x25
     64#define BD6107_MSLOPE				0x26
     65#define BD6107_RGBSLOPE				0x27
     66#define BD6107_TEST				0x29
     67#define BD6107_SFTRST				0x2a
     68#define BD6107_SFTRSTGD				0x2b
     69
     70struct bd6107 {
     71	struct i2c_client *client;
     72	struct backlight_device *backlight;
     73	struct bd6107_platform_data *pdata;
     74	struct gpio_desc *reset;
     75};
     76
     77static int bd6107_write(struct bd6107 *bd, u8 reg, u8 data)
     78{
     79	return i2c_smbus_write_byte_data(bd->client, reg, data);
     80}
     81
     82static int bd6107_backlight_update_status(struct backlight_device *backlight)
     83{
     84	struct bd6107 *bd = bl_get_data(backlight);
     85	int brightness = backlight_get_brightness(backlight);
     86
     87	if (brightness) {
     88		bd6107_write(bd, BD6107_PORTSEL, BD6107_PORTSEL_LEDM(2) |
     89			     BD6107_PORTSEL_LEDM(1) | BD6107_PORTSEL_LEDM(0));
     90		bd6107_write(bd, BD6107_MAINCNT1, brightness);
     91		bd6107_write(bd, BD6107_LEDCNT1, BD6107_LEDCNT1_LEDONOFF1);
     92	} else {
     93		/* Assert the reset line (gpiolib will handle active low) */
     94		gpiod_set_value(bd->reset, 1);
     95		msleep(24);
     96		gpiod_set_value(bd->reset, 0);
     97	}
     98
     99	return 0;
    100}
    101
    102static int bd6107_backlight_check_fb(struct backlight_device *backlight,
    103				       struct fb_info *info)
    104{
    105	struct bd6107 *bd = bl_get_data(backlight);
    106
    107	return bd->pdata->fbdev == NULL || bd->pdata->fbdev == info->dev;
    108}
    109
    110static const struct backlight_ops bd6107_backlight_ops = {
    111	.options	= BL_CORE_SUSPENDRESUME,
    112	.update_status	= bd6107_backlight_update_status,
    113	.check_fb	= bd6107_backlight_check_fb,
    114};
    115
    116static int bd6107_probe(struct i2c_client *client,
    117			  const struct i2c_device_id *id)
    118{
    119	struct bd6107_platform_data *pdata = dev_get_platdata(&client->dev);
    120	struct backlight_device *backlight;
    121	struct backlight_properties props;
    122	struct bd6107 *bd;
    123	int ret;
    124
    125	if (pdata == NULL) {
    126		dev_err(&client->dev, "No platform data\n");
    127		return -EINVAL;
    128	}
    129
    130	if (!i2c_check_functionality(client->adapter,
    131				     I2C_FUNC_SMBUS_BYTE_DATA)) {
    132		dev_warn(&client->dev,
    133			 "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
    134		return -EIO;
    135	}
    136
    137	bd = devm_kzalloc(&client->dev, sizeof(*bd), GFP_KERNEL);
    138	if (!bd)
    139		return -ENOMEM;
    140
    141	bd->client = client;
    142	bd->pdata = pdata;
    143
    144	/*
    145	 * Request the reset GPIO line with GPIOD_OUT_HIGH meaning asserted,
    146	 * so in the machine descriptor table (or other hardware description),
    147	 * the line should be flagged as active low so this will assert
    148	 * the reset.
    149	 */
    150	bd->reset = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_HIGH);
    151	if (IS_ERR(bd->reset)) {
    152		dev_err(&client->dev, "unable to request reset GPIO\n");
    153		ret = PTR_ERR(bd->reset);
    154		return ret;
    155	}
    156
    157	memset(&props, 0, sizeof(props));
    158	props.type = BACKLIGHT_RAW;
    159	props.max_brightness = 128;
    160	props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
    161				   props.max_brightness);
    162
    163	backlight = devm_backlight_device_register(&client->dev,
    164					      dev_name(&client->dev),
    165					      &bd->client->dev, bd,
    166					      &bd6107_backlight_ops, &props);
    167	if (IS_ERR(backlight)) {
    168		dev_err(&client->dev, "failed to register backlight\n");
    169		return PTR_ERR(backlight);
    170	}
    171
    172	backlight_update_status(backlight);
    173	i2c_set_clientdata(client, backlight);
    174
    175	return 0;
    176}
    177
    178static int bd6107_remove(struct i2c_client *client)
    179{
    180	struct backlight_device *backlight = i2c_get_clientdata(client);
    181
    182	backlight->props.brightness = 0;
    183	backlight_update_status(backlight);
    184
    185	return 0;
    186}
    187
    188static const struct i2c_device_id bd6107_ids[] = {
    189	{ "bd6107", 0 },
    190	{ }
    191};
    192MODULE_DEVICE_TABLE(i2c, bd6107_ids);
    193
    194static struct i2c_driver bd6107_driver = {
    195	.driver = {
    196		.name = "bd6107",
    197	},
    198	.probe = bd6107_probe,
    199	.remove = bd6107_remove,
    200	.id_table = bd6107_ids,
    201};
    202
    203module_i2c_driver(bd6107_driver);
    204
    205MODULE_DESCRIPTION("Rohm BD6107 Backlight Driver");
    206MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
    207MODULE_LICENSE("GPL");