Files
OpenCellular/common/backlight_lid.c
Jett Rink d52ba1a4d4 backlight: Adding support for active low GPIO signal
BUG=b:72007261
BRANCH=none
TEST=Verified with grunt board (with is active low)

Change-Id: I9a58148b8d92065bec982071ed1d97a466197e9a
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/872233
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-by: Edward Hill <ecgh@chromium.org>
2018-01-18 05:09:37 -08:00

85 lines
1.9 KiB
C

/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Backlight control based on lid and optional request signal from AP */
#include "common.h"
#include "gpio.h"
#include "hooks.h"
#include "host_command.h"
#include "lid_switch.h"
/**
* Activate/Deactivate the backlight GPIO pin considering active high or low.
*/
void enable_backlight(int enabled)
{
#ifdef CONFIG_BACKLIGHT_LID_ACTIVE_LOW
gpio_set_level(GPIO_ENABLE_BACKLIGHT_L, !enabled);
#else
gpio_set_level(GPIO_ENABLE_BACKLIGHT, enabled);
#endif
}
/**
* Update backlight state.
*/
static void update_backlight(void)
{
#ifdef CONFIG_BACKLIGHT_REQ_GPIO
/* Enable the backlight if lid is open AND requested by AP */
enable_backlight(lid_is_open() &&
gpio_get_level(CONFIG_BACKLIGHT_REQ_GPIO));
#else
/*
* Enable backlight if lid is open; this is AND'd with the request from
* the AP in hardware.
*/
enable_backlight(lid_is_open());
#endif
}
DECLARE_HOOK(HOOK_LID_CHANGE, update_backlight, HOOK_PRIO_DEFAULT);
/**
* Initialize backlight module.
*/
static void backlight_init(void)
{
update_backlight();
#ifdef CONFIG_BACKLIGHT_REQ_GPIO
gpio_enable_interrupt(CONFIG_BACKLIGHT_REQ_GPIO);
#endif
}
DECLARE_HOOK(HOOK_INIT, backlight_init, HOOK_PRIO_DEFAULT);
#ifdef CONFIG_BACKLIGHT_REQ_GPIO
void backlight_interrupt(enum gpio_signal signal)
{
update_backlight();
}
#endif
/**
* Host command to toggle backlight.
*
* The requested state will persist until the next lid-switch or request-gpio
* transition.
*/
static int switch_command_enable_backlight(struct host_cmd_handler_args *args)
{
const struct ec_params_switch_enable_backlight *p = args->params;
enable_backlight(p->enabled);
return EC_RES_SUCCESS;
}
DECLARE_HOST_COMMAND(EC_CMD_SWITCH_ENABLE_BKLIGHT,
switch_command_enable_backlight,
EC_VER_MASK(0));