1 files changed, 105 insertions, 0 deletions
diff --git a/board/samus/panel.c b/board/samus/panel.c
new file mode 100644
index 0000000000..5704179d5d
--- /dev/null
+++ b/board/samus/panel.c
@@ -0,0 +1,105 @@
+/* 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.
+ */
+
+#include "chipset.h"
+#include "common.h"
+#include "console.h"
+#include "gpio.h"
+#include "hooks.h"
+#include "host_command.h"
+#include "i2c.h"
+#include "lid_switch.h"
+
+#define LP8555_REG_COMMAND           0x00
+#define  LP8555_REG_COMMAND_ON       0x01
+#define LP8555_REG_CONFIG            0x10
+#define  LP8555_REG_CONFIG_MODE_MASK 0x03
+#define  LP8555_REG_CONFIG_MODE_PWM  0x00
+
+/**
+ * Enable PWM mode in backlight controller and turn it on.
+ */
+static int lp8555_enable_pwm_mode(void)
+{
+	int reg;
+
+	/* Enable PWM mode. */
+	i2c_read8(I2C_PORT_BACKLIGHT, I2C_ADDR_BACKLIGHT,
+		  LP8555_REG_CONFIG, &reg);
+	reg &= ~LP8555_REG_CONFIG_MODE_MASK;
+	reg |= LP8555_REG_CONFIG_MODE_PWM;
+	i2c_write8(I2C_PORT_BACKLIGHT, I2C_ADDR_BACKLIGHT,
+		   LP8555_REG_CONFIG, reg);
+
+	/* Power on. */
+	i2c_read8(I2C_PORT_BACKLIGHT, I2C_ADDR_BACKLIGHT,
+		  LP8555_REG_COMMAND, &reg);
+	reg |= LP8555_REG_COMMAND_ON;
+	i2c_write8(I2C_PORT_BACKLIGHT, I2C_ADDR_BACKLIGHT,
+		   LP8555_REG_COMMAND, reg);
+
+	return EC_SUCCESS;
+}
+
+/**
+ * Host command to toggle backlight.
+ */
+static int switch_command_enable_backlight(struct host_cmd_handler_args *args)
+{
+	const struct ec_params_switch_enable_backlight *p = args->params;
+
+	gpio_set_level(GPIO_ENABLE_BACKLIGHT, p->enabled);
+
+	if (p->enabled)
+		lp8555_enable_pwm_mode();
+
+	return EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_SWITCH_ENABLE_BKLIGHT,
+		     switch_command_enable_backlight,
+		     EC_VER_MASK(0));
+
+/**
+ * Hook to turn backlight PWM mode on if it turns off.
+ */
+static void backlight_pwm_mode_hook(void)
+{
+	int reg;
+
+	/* Only check if the system is powered. */
+	if (!chipset_in_state(CHIPSET_STATE_ON))
+		return;
+
+	/* Read current command reg to see if it is on. */
+	i2c_read8(I2C_PORT_BACKLIGHT, I2C_ADDR_BACKLIGHT,
+		  LP8555_REG_COMMAND, &reg);
+
+	/* Turn it on if needed. */
+	if (!(reg & LP8555_REG_COMMAND_ON))
+		lp8555_enable_pwm_mode();
+}
+DECLARE_HOOK(HOOK_SECOND, backlight_pwm_mode_hook, HOOK_PRIO_LAST);
+
+/**
+ * Update backlight state.
+ */
+static void update_backlight(void)
+{
+	/*
+	 * Enable backlight if lid is open; this is AND'd with the request from
+	 * the AP in hardware.
+	 */
+	gpio_set_level(GPIO_ENABLE_BACKLIGHT, lid_is_open());
+}
+DECLARE_HOOK(HOOK_LID_CHANGE, update_backlight, HOOK_PRIO_DEFAULT);
+
+/**
+ * Initialize backlight module.
+ */
+static void backlight_init(void)
+{
+	update_backlight();
+}
+DECLARE_HOOK(HOOK_INIT, backlight_init, HOOK_PRIO_DEFAULT);