Signed-off-by: Richard Vidal-Dorsch <richard.dorsch@xxxxxxxxx>
---
drivers/video/backlight/Kconfig | 8 ++
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/imanager_bl.c | 210 ++++++++++++++++++++++++++++++++++
3 files changed, 219 insertions(+)
create mode 100644 drivers/video/backlight/imanager_bl.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 5ffa4b4..2dac696 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -251,6 +251,14 @@ config BACKLIGHT_HP700
If you have an HP Jornada 700 series,
say Y to include backlight control driver.
+config BACKLIGHT_IMANAGER
+ tristate "Advantech iManager Backlight/Brightness"
+ depends on MFD_IMANAGER
+ help
+ This enables support for Advantech iManager Backlight and
+ Brightness control of some Advantech SOM, MIO, AIMB, and
+ PCM modules/boards.
+
config BACKLIGHT_CARILLO_RANCH
tristate "Intel Carillo Ranch Backlight Driver"
depends on LCD_CLASS_DEVICE && PCI && X86 && FB_LE80578
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 16ec534..713b406 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_BACKLIGHT_GENERIC) += generic_bl.o
obj-$(CONFIG_BACKLIGHT_GPIO) += gpio_backlight.o
obj-$(CONFIG_BACKLIGHT_HP680) += hp680_bl.o
obj-$(CONFIG_BACKLIGHT_HP700) += jornada720_bl.o
+obj-$(CONFIG_BACKLIGHT_IMANAGER) += imanager_bl.o
obj-$(CONFIG_BACKLIGHT_IPAQ_MICRO) += ipaq_micro_bl.o
obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o
obj-$(CONFIG_BACKLIGHT_LM3630A) += lm3630a_bl.o
diff --git a/drivers/video/backlight/imanager_bl.c b/drivers/video/backlight/imanager_bl.c
new file mode 100644
index 0000000..d8b4e3d
--- /dev/null
+++ b/drivers/video/backlight/imanager_bl.c
@@ -0,0 +1,210 @@
+/*
+ * Advantech iManager Backlight driver
+ * Partially derived from wm831x_bl
+ *
+ * Copyright (C) 2016 Advantech Co., Ltd.
+ * Author: Richard Vidal-Dorsch <richard.dorsch@xxxxxxxxxxxxx>
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/backlight.h>
+#include <linux/device.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mfd/imanager.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+#define BL_MAX_PWM 100
+
+enum backlight_units { BL_UNIT_1 = 0, BL_UNIT_2 };
+
+static bool polarity = PWM_POLARITY_NORMAL;
+module_param(polarity, bool, 0444);
+MODULE_PARM_DESC(polarity, "Select backlight polarity (inverted := 1)");
+
+static ushort unit = BL_UNIT_1;
+module_param(unit, ushort, 0444);
+MODULE_PARM_DESC(unit, "Select backlight control unit [0, 1] (defaults to 0)");
+
+struct imanager_backlight_data {
+ struct imanager_device_data *imgr;
+};
+
+struct brightness_level {
+ uint value : 7, /* Brightness Value - LSB [6..0] */
+ enable : 1; /* Brightness Enable - MSB [7] */
+};
+
+struct backlight_ctrl {
+ uint enable : 1, /* Backlight Control Enable - LSB [0] */
+ pwmpol : 1, /* PWM Polarity - bit [1] */
+ blpol : 1, /* Backlight Polarity - bit [2] */
+ dnc : 5; /* Don't care - bit [7..3] */
+};
+
+static int imanager_bl_enable(struct imanager_ec_data *ec, int unit)
+{
+ u8 val8;
+ struct brightness_level *ctrl = (struct brightness_level *)&val8;
+ u8 devid = ec->bl.attr[unit]->did;
+ u8 bl_unit = ec->bl.brightness[unit];
+ int ret;
+
+ ret = imanager_read_ram(ec, EC_RAM_ACPI, bl_unit, &val8, sizeof(val8));
+ if (ret < 0)
+ return ret;
+
+ ctrl->enable = 1;
+
+ return imanager_write_ram(ec, EC_RAM_ACPI, devid, &val8, sizeof(val8));
+}
+
+static int imanager_bl_set_polarity(struct imanager_ec_data *ec, uint polarity)
+{
+ u8 val8;
+ struct backlight_ctrl *ctrl = (struct backlight_ctrl *)&val8;
+ int ret;
+
+ ret = imanager_read_ram(ec, EC_RAM_ACPI, EC_OFFSET_BACKLIGHT_CTRL,
+ &val8, sizeof(val8));
+ if (ret < 0)
+ return ret;
+
+ ctrl->blpol = polarity ? 1 : 0;
+
+ return imanager_write_ram(ec, EC_RAM_ACPI, EC_OFFSET_BACKLIGHT_CTRL,
+ &val8, sizeof(val8));
+}
+
+static int imanager_bl_get_brightness(struct backlight_device *bd)
+{
+ struct imanager_backlight_data *data = bl_get_data(bd);
+ struct imanager_device_data *imgr = data->imgr;
+ u8 devid = imgr->ec.bl.attr[unit]->did;
+ int pwm;
+
+ mutex_lock(&imgr->lock);
+
+ pwm = imanager_read8(&imgr->ec, EC_CMD_HWP_RD, devid);
+ if (pwm < 0) {
+ dev_warn(&bd->dev, "Failed while reading PWM\n");
+ pwm = 0;
+ }
+
+ mutex_unlock(&imgr->lock);
+
+ return polarity ? BL_MAX_PWM - pwm : pwm;
+}
+
+static int imanager_bl_set_brightness(struct backlight_device *bd)
+{
+ struct imanager_backlight_data *data = bl_get_data(bd);
+ struct imanager_device_data *imgr = data->imgr;
+ u8 devid = imgr->ec.bl.attr[unit]->did;
+ u8 brightness = bd->props.brightness;
+ int ret;
+
+ if (bd->props.power != FB_BLANK_UNBLANK)
+ brightness = 0;
+
+ if (bd->props.fb_blank != FB_BLANK_UNBLANK)
+ brightness = 0;
+
+ if (bd->props.state & BL_CORE_SUSPENDED)
+ brightness = 0;
+
+ /* invert brightness if polarity is set */
+ brightness = polarity ? BL_MAX_PWM - brightness : brightness;
+
+ mutex_lock(&imgr->lock);
+ ret = imanager_write8(&imgr->ec, EC_CMD_HWP_WR, devid, brightness);
+ mutex_unlock(&imgr->lock);
+
+ return ret;
+}
+
+static const struct backlight_ops imanager_bl_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .get_brightness = imanager_bl_get_brightness,
+ .update_status = imanager_bl_set_brightness,
+};
+
+static int imanager_bl_init(struct device *dev,
+ struct imanager_backlight_data *data)
+{
+ struct backlight_device *bd;
+ struct backlight_properties props;
+ int ret;
+
+ memset(&props, 0, sizeof(props));
+ props.type = BACKLIGHT_PLATFORM;
+ props.max_brightness = BL_MAX_PWM;
+ bd = devm_backlight_device_register(dev, "imanager-backlight", dev,
+ data, &imanager_bl_ops, &props);
+
+ if (IS_ERR(bd)) {
+ dev_err(dev, "Unable to register backlight device\n");
+ return PTR_ERR(bd);
+ }
+
+ bd->props.brightness = imanager_bl_get_brightness(bd);
+ bd->props.max_brightness = BL_MAX_PWM;
+ bd->props.power = FB_BLANK_UNBLANK;
+
+ backlight_update_status(bd);
+
+ ret = imanager_bl_enable(&data->imgr->ec, unit);
+ if (ret < 0)
+ dev_warn(dev, "Could not enable backlight control\n");
+
+ ret = imanager_bl_set_polarity(&data->imgr->ec, polarity);
+ if (ret < 0)
+ dev_warn(dev, "Could not set backlight polarity\n");
+
+ return 0;
+}
+
+static int imanager_bl_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct imanager_device_data *imgr = dev_get_drvdata(dev->parent);
+ struct imanager_backlight_data *data;
+ int ret;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->imgr = imgr;
+
+ ret = imanager_bl_init(dev, data);
+ if (ret)
+ return ret;
+
+ platform_set_drvdata(pdev, data);
+
+ return 0;
+}
+
+static struct platform_driver imanager_backlight_driver = {
+ .driver = {
+ .name = "imanager-backlight",
+ },
+ .probe = imanager_bl_probe,
+};
+
+module_platform_driver(imanager_backlight_driver);
+
+MODULE_DESCRIPTION("Advantech iManager Backlight driver");
+MODULE_AUTHOR("Richard Vidal-Dorsch <richard.dorsch at advantech.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:imanager-backlight");
--
2.10.1
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