backlight: Add ROHM BD6107 backlight driver

The BD6107 is a multi-purpose 10 channels LED driver for the mobile
market. Only the main channel is supported by this driver.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

4 files changed, 239 insertions, 0 deletions

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index b304e075cf3a..d4a7a351d67c 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -438,6 +438,12 @@ config BACKLIGHT_LV5207LP
         help
           If you have a Sanyo LV5207LP say Y to enable the backlight driver.
 
+config BACKLIGHT_BD6107
+        tristate "Rohm BD6107 Backlight"
+        depends on I2C
+        help
+          If you have a Rohm BD6107 say Y to enable the backlight driver.
+
 endif # BACKLIGHT_CLASS_DEVICE
 
 endif # BACKLIGHT_LCD_SUPPORT
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 4e5e8116c8c4..38e1babb1946 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_BACKLIGHT_ADP8870)		+= adp8870_bl.o
 obj-$(CONFIG_BACKLIGHT_APPLE)           += apple_bl.o
 obj-$(CONFIG_BACKLIGHT_AS3711)          += as3711_bl.o
 obj-$(CONFIG_BACKLIGHT_ATMEL_PWM)       += atmel-pwm-bl.o
+obj-$(CONFIG_BACKLIGHT_BD6107)          += bd6107.o
 obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH)   += cr_bllcd.o
 obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE)    += backlight.o
 obj-$(CONFIG_BACKLIGHT_DA903X)          += da903x_bl.o
diff --git a/drivers/video/backlight/bd6107.c b/drivers/video/backlight/bd6107.c
new file mode 100644
index 000000000000..15e3294b29fe
--- /dev/null
+++ b/drivers/video/backlight/bd6107.c
@@ -0,0 +1,213 @@
+/*
+ * ROHM Semiconductor BD6107 LED Driver
+ *
+ * Copyright (C) 2013 Ideas on board SPRL
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/platform_data/bd6107.h>
+#include <linux/slab.h>
+
+#define BD6107_PSCNT1                           0x00
+#define BD6107_PSCNT1_PSCNTREG2                 (1 << 2)
+#define BD6107_PSCNT1_PSCNTREG1                 (1 << 0)
+#define BD6107_REGVSET                          0x02
+#define BD6107_REGVSET_REG1VSET_2_85V           (1 << 2)
+#define BD6107_REGVSET_REG1VSET_2_80V           (0 << 2)
+#define BD6107_LEDCNT1                          0x03
+#define BD6107_LEDCNT1_LEDONOFF2                (1 << 1)
+#define BD6107_LEDCNT1_LEDONOFF1                (1 << 0)
+#define BD6107_PORTSEL                          0x04
+#define BD6107_PORTSEL_LEDM(n)                  (1 << (n))
+#define BD6107_RGB1CNT1                         0x05
+#define BD6107_RGB1CNT2                         0x06
+#define BD6107_RGB1CNT3                         0x07
+#define BD6107_RGB1CNT4                         0x08
+#define BD6107_RGB1CNT5                         0x09
+#define BD6107_RGB1FLM                          0x0a
+#define BD6107_RGB2CNT1                         0x0b
+#define BD6107_RGB2CNT2                         0x0c
+#define BD6107_RGB2CNT3                         0x0d
+#define BD6107_RGB2CNT4                         0x0e
+#define BD6107_RGB2CNT5                         0x0f
+#define BD6107_RGB2FLM                          0x10
+#define BD6107_PSCONT3                          0x11
+#define BD6107_SMMONCNT                         0x12
+#define BD6107_DCDCCNT                          0x13
+#define BD6107_IOSEL                            0x14
+#define BD6107_OUT1                             0x15
+#define BD6107_OUT2                             0x16
+#define BD6107_MASK1                            0x17
+#define BD6107_MASK2                            0x18
+#define BD6107_FACTOR1                          0x19
+#define BD6107_FACTOR2                          0x1a
+#define BD6107_CLRFACT1                         0x1b
+#define BD6107_CLRFACT2                         0x1c
+#define BD6107_STATE1                           0x1d
+#define BD6107_LSIVER                           0x1e
+#define BD6107_GRPSEL                           0x1f
+#define BD6107_LEDCNT2                          0x20
+#define BD6107_LEDCNT3                          0x21
+#define BD6107_MCURRENT                         0x22
+#define BD6107_MAINCNT1                         0x23
+#define BD6107_MAINCNT2                         0x24
+#define BD6107_SLOPECNT                         0x25
+#define BD6107_MSLOPE                           0x26
+#define BD6107_RGBSLOPE                         0x27
+#define BD6107_TEST                             0x29
+#define BD6107_SFTRST                           0x2a
+#define BD6107_SFTRSTGD                         0x2b
+
+struct bd6107 {
+        struct i2c_client *client;
+        struct backlight_device *backlight;
+        struct bd6107_platform_data *pdata;
+};
+
+static int bd6107_write(struct bd6107 *bd, u8 reg, u8 data)
+{
+        return i2c_smbus_write_byte_data(bd->client, reg, data);
+}
+
+static int bd6107_backlight_update_status(struct backlight_device *backlight)
+{
+        struct bd6107 *bd = bl_get_data(backlight);
+        int brightness = backlight->props.brightness;
+
+        if (backlight->props.power != FB_BLANK_UNBLANK ||
+            backlight->props.fb_blank != FB_BLANK_UNBLANK ||
+            backlight->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
+                brightness = 0;
+
+        if (brightness) {
+                bd6107_write(bd, BD6107_PORTSEL, BD6107_PORTSEL_LEDM(2) |
+                             BD6107_PORTSEL_LEDM(1) | BD6107_PORTSEL_LEDM(0));
+                bd6107_write(bd, BD6107_MAINCNT1, brightness);
+                bd6107_write(bd, BD6107_LEDCNT1, BD6107_LEDCNT1_LEDONOFF1);
+        } else {
+                gpio_set_value(bd->pdata->reset, 0);
+                msleep(24);
+                gpio_set_value(bd->pdata->reset, 1);
+        }
+
+        return 0;
+}
+
+static int bd6107_backlight_get_brightness(struct backlight_device *backlight)
+{
+        return backlight->props.brightness;
+}
+
+static int bd6107_backlight_check_fb(struct backlight_device *backlight,
+                                       struct fb_info *info)
+{
+        struct bd6107 *bd = bl_get_data(backlight);
+
+        return bd->pdata->fbdev == NULL || bd->pdata->fbdev == info->dev;
+}
+
+static const struct backlight_ops bd6107_backlight_ops = {
+        .options        = BL_CORE_SUSPENDRESUME,
+        .update_status  = bd6107_backlight_update_status,
+        .get_brightness = bd6107_backlight_get_brightness,
+        .check_fb       = bd6107_backlight_check_fb,
+};
+
+static int bd6107_probe(struct i2c_client *client,
+                          const struct i2c_device_id *id)
+{
+        struct bd6107_platform_data *pdata = client->dev.platform_data;
+        struct backlight_device *backlight;
+        struct backlight_properties props;
+        struct bd6107 *bd;
+        int ret;
+
+        if (pdata == NULL || !pdata->reset) {
+                dev_err(&client->dev, "No reset GPIO in platform data\n");
+                return -EINVAL;
+        }
+
+        if (!i2c_check_functionality(client->adapter,
+                                     I2C_FUNC_SMBUS_BYTE_DATA)) {
+                dev_warn(&client->dev,
+                         "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
+                return -EIO;
+        }
+
+        bd = devm_kzalloc(&client->dev, sizeof(*bd), GFP_KERNEL);
+        if (!bd)
+                return -ENOMEM;
+
+        bd->client = client;
+        bd->pdata = pdata;
+
+        ret = devm_gpio_request_one(&client->dev, pdata->reset,
+                                    GPIOF_DIR_OUT | GPIOF_INIT_LOW, "reset");
+        if (ret < 0) {
+                dev_err(&client->dev, "unable to request reset GPIO\n");
+                return ret;
+        }
+
+        memset(&props, 0, sizeof(props));
+        props.type = BACKLIGHT_RAW;
+        props.max_brightness = 128;
+        props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
+                                   props.max_brightness);
+
+        backlight = backlight_device_register(dev_name(&client->dev),
+                                              &bd->client->dev, bd,
+                                              &bd6107_backlight_ops, &props);
+        if (IS_ERR(backlight)) {
+                dev_err(&client->dev, "failed to register backlight\n");
+                return PTR_ERR(backlight);
+        }
+
+        backlight_update_status(backlight);
+        i2c_set_clientdata(client, backlight);
+
+        return 0;
+}
+
+static int bd6107_remove(struct i2c_client *client)
+{
+        struct backlight_device *backlight = i2c_get_clientdata(client);
+
+        backlight->props.brightness = 0;
+        backlight_update_status(backlight);
+        backlight_device_unregister(backlight);
+
+        return 0;
+}
+
+static const struct i2c_device_id bd6107_ids[] = {
+        { "bd6107", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, bd6107_ids);
+
+static struct i2c_driver bd6107_driver = {
+        .driver = {
+                .name = "bd6107",
+        },
+        .probe = bd6107_probe,
+        .remove = bd6107_remove,
+        .id_table = bd6107_ids,
+};
+
+module_i2c_driver(bd6107_driver);
+
+MODULE_DESCRIPTION("Rohm BD6107 Backlight Driver");
+MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/platform_data/bd6107.h b/include/linux/platform_data/bd6107.h
new file mode 100644
index 000000000000..671d6502d241
--- /dev/null
+++ b/include/linux/platform_data/bd6107.h
@@ -0,0 +1,19 @@
+/*
+ * bd6107.h - Rohm BD6107 LEDs Driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __BD6107_H__
+#define __BD6107_H__
+
+struct device;
+
+struct bd6107_platform_data {
+        struct device *fbdev;
+        int reset;                      /* Reset GPIO */
+        unsigned int def_value;
+};
+
+#endif