video: support exynos pwm backlight driver

This patch support exynos pwm backlight driver. It can control backlight
power and brightness by using pwm.

Signed-off-by: Donghwa Lee <dh09.lee@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

arch/arm/include/asm/arch-exynos/pwm_backlight.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2012 Samsung Electronics
+ *
+ * Author: Donghwa Lee <dh09.lee@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef _PWM_BACKLIGHT_H_
+#define _PWM_BACKLIGHT_H_
+
+struct pwm_backlight_data {
+	int pwm_id;
+	int period;
+	int max_brightness;
+	int brightness;
+};
+
+extern int exynos_pwm_backlight_init(struct pwm_backlight_data *pd);
+
+#endif /* _PWM_BACKLIGHT_H_ */

drivers/video/Makefile

@@ -33,6 +33,7 @@ COBJS-$(CONFIG_EXYNOS_DP) += exynos_dp.o exynos_dp_lowlevel.o
 COBJS-$(CONFIG_EXYNOS_FB) += exynos_fb.o exynos_fimd.o
 COBJS-$(CONFIG_EXYNOS_MIPI_DSIM) += exynos_mipi_dsi.o exynos_mipi_dsi_common.o \
 				exynos_mipi_dsi_lowlevel.o
+COBJS-$(CONFIG_EXYNOS_PWM_BL) += exynos_pwm_bl.o
 COBJS-$(CONFIG_FSL_DIU_FB) += fsl_diu_fb.o videomodes.o
 COBJS-$(CONFIG_S6E8AX0) += s6e8ax0.o
 COBJS-$(CONFIG_S6E63D6) += s6e63d6.o

drivers/video/exynos_pwm_bl.c

@@ -0,0 +1,57 @@
+/*
+ * PWM BACKLIGHT driver for Board based on EXYNOS.
+ *
+ * Author: Donghwa Lee  <dh09.lee@samsung.com>
+ *
+ * Derived from linux/drivers/video/backlight/pwm_backlight.c
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include <common.h>
+#include <pwm.h>
+#include <linux/types.h>
+#include <asm/io.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/gpio.h>
+#include <asm/arch/pwm.h>
+#include <asm/arch/pwm_backlight.h>
+
+static struct pwm_backlight_data *pwm;
+
+static int exynos_pwm_backlight_update_status(void)
+{
+	int brightness = pwm->brightness;
+	int max = pwm->max_brightness;
+
+	if (brightness == 0) {
+		pwm_config(pwm->pwm_id, 0, pwm->period);
+		pwm_disable(pwm->pwm_id);
+	} else {
+		pwm_config(pwm->pwm_id,
+			brightness * pwm->period / max, pwm->period);
+		pwm_enable(pwm->pwm_id);
+	}
+	return 0;
+}
+
+int exynos_pwm_backlight_init(struct pwm_backlight_data *pd)
+{
+	pwm = pd;
+
+	exynos_pwm_backlight_update_status();
+
+	return 0;
+}