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- diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
- index d83c87b90..2f1b6105e 100644
- --- a/drivers/video/backlight/Kconfig
- +++ b/drivers/video/backlight/Kconfig
- @@ -456,6 +456,12 @@ config BACKLIGHT_LED
- If you have a LCD backlight adjustable by LED class driver, say Y
- to enable this driver.
-
- +config BACKLIGHT_OCP8178
- + tristate "OCP8178 Backlight Driver"
- + depends on GPIOLIB
- + help
- + If you have an OCP8178, say Y to enable the backlight driver.
- +
- endif # BACKLIGHT_CLASS_DEVICE
-
- endmenu
- diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
- index 685f3f1ca..f1160d626 100644
- --- a/drivers/video/backlight/Makefile
- +++ b/drivers/video/backlight/Makefile
- @@ -57,3 +57,4 @@ obj-$(CONFIG_BACKLIGHT_WM831X) += wm831x_bl.o
- obj-$(CONFIG_BACKLIGHT_ARCXCNN) += arcxcnn_bl.o
- obj-$(CONFIG_BACKLIGHT_RAVE_SP) += rave-sp-backlight.o
- obj-$(CONFIG_BACKLIGHT_LED) += led_bl.o
- +obj-$(CONFIG_BACKLIGHT_OCP8178) += ocp8178_bl.o
- diff --git a/drivers/video/backlight/ocp8178_bl.c b/drivers/video/backlight/ocp8178_bl.c
- new file mode 100644
- index 000000000..db8db1771
- --- /dev/null
- +++ b/drivers/video/backlight/ocp8178_bl.c
- @@ -0,0 +1,277 @@
- +/*
- + * ocp8178_bl.c - ocp8178 backlight 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.
- + */
- +
- +#include <linux/backlight.h>
- +#include <linux/err.h>
- +#include <linux/fb.h>
- +#include <linux/gpio.h> /* Only for legacy support */
- +#include <linux/gpio/consumer.h>
- +#include <linux/init.h>
- +#include <linux/kernel.h>
- +#include <linux/module.h>
- +#include <linux/of.h>
- +#include <linux/of_gpio.h>
- +#include <linux/platform_data/gpio_backlight.h>
- +#include <linux/platform_device.h>
- +#include <linux/slab.h>
- +#include <linux/delay.h>
- +#include <linux/timer.h>
- +#include <linux/poll.h>
- +#include <linux/proc_fs.h>
- +#include <linux/seq_file.h>
- +#include <linux/sched.h>
- +#include <linux/interrupt.h>
- +#include <linux/irq.h>
- +#include <linux/io.h>
- +#include <linux/clk.h>
- +
- +struct ocp8178_backlight {
- + struct device *dev;
- + struct device *fbdev;
- +
- + struct gpio_desc *gpiod;
- + int def_value;
- + int current_value;
- +};
- +
- +#define DETECT_DELAY 200
- +#define DETECT_TIME 500
- +#define DETECT_WINDOW_TIME 1000
- +#define START_TIME 10
- +#define END_TIME 10
- +#define SHUTDOWN_TIME 3000
- +#define LOW_BIT_HIGH_TIME 10
- +#define LOW_BIT_LOW_TIME 50
- +#define HIGH_BIT_HIGH_TIME 50
- +#define HIGH_BIT_LOW_TIME 10
- +#define MAX_BRIGHTNESS_VALUE 9
- +
- +static void entry_1wire_mode(struct ocp8178_backlight *gbl)
- +{
- + unsigned long flags = 0;
- + local_irq_save(flags);
- + gpiod_set_value(gbl->gpiod, 0);
- + mdelay(SHUTDOWN_TIME/1000);
- + gpiod_set_value(gbl->gpiod, 1);
- + udelay(DETECT_DELAY);
- + gpiod_set_value(gbl->gpiod, 0);
- + udelay(DETECT_TIME);
- + gpiod_set_value(gbl->gpiod, 1);
- + udelay(DETECT_WINDOW_TIME);
- + local_irq_restore(flags);
- +}
- +
- +static inline void write_bit(struct ocp8178_backlight *gbl, int bit)
- +{
- + if (bit) {
- + gpiod_set_value(gbl->gpiod, 0);
- + udelay(HIGH_BIT_LOW_TIME);
- + gpiod_set_value(gbl->gpiod, 1);
- + udelay(HIGH_BIT_HIGH_TIME);
- + } else {
- + gpiod_set_value(gbl->gpiod, 0);
- + udelay(LOW_BIT_LOW_TIME);
- + gpiod_set_value(gbl->gpiod, 1);
- + udelay(LOW_BIT_HIGH_TIME);
- + }
- +}
- +
- +static void write_byte(struct ocp8178_backlight *gbl, int byte)
- +{
- + unsigned long flags = 0;
- + unsigned char data = 0x72;
- + int i;
- +
- + local_irq_save(flags);
- +
- + gpiod_set_value(gbl->gpiod, 1);
- + udelay(START_TIME);
- + for(i = 0; i < 8; i++) {
- + if(data & 0x80) {
- + write_bit(gbl, 1);
- + } else {
- + write_bit(gbl, 0);
- + }
- + data <<= 1;
- + }
- + gpiod_set_value(gbl->gpiod, 0);
- + udelay(END_TIME);
- +
- + data = byte & 0x1f;
- +
- + gpiod_set_value(gbl->gpiod, 1);
- + udelay(START_TIME);
- + for(i = 0; i < 8; i++) {
- + if(data & 0x80) {
- + write_bit(gbl, 1);
- + } else {
- + write_bit(gbl, 0);
- + }
- + data <<= 1;
- + }
- + gpiod_set_value(gbl->gpiod, 0);
- + udelay(END_TIME);
- + gpiod_set_value(gbl->gpiod, 1);
- +
- + local_irq_restore(flags);
- +}
- +
- +unsigned char ocp8178_bl_table[MAX_BRIGHTNESS_VALUE+1] = {0, 1, 4, 8, 12, 16, 20, 24, 28, 31};
- +
- +static int ocp8178_update_status(struct backlight_device *bl)
- +{
- + struct ocp8178_backlight *gbl = bl_get_data(bl);
- + int brightness = bl->props.brightness, i;
- +
- + if (bl->props.power != FB_BLANK_UNBLANK ||
- + bl->props.fb_blank != FB_BLANK_UNBLANK ||
- + bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
- + brightness = 0;
- +
- + if(brightness > MAX_BRIGHTNESS_VALUE)
- + brightness = MAX_BRIGHTNESS_VALUE;
- +
- + for(i = 0; i < 2; i++) {
- + entry_1wire_mode(gbl);
- + write_byte(gbl, ocp8178_bl_table[brightness]);
- + }
- + gbl->current_value = brightness;
- +
- + return 0;
- +}
- +
- +static int ocp8178_get_brightness(struct backlight_device *bl)
- +{
- + struct ocp8178_backlight *gbl = bl_get_data(bl);
- + return gbl->current_value;
- +}
- +
- +static int ocp8178_check_fb(struct backlight_device *bl,
- + struct fb_info *info)
- +{
- + struct ocp8178_backlight *gbl = bl_get_data(bl);
- + return gbl->fbdev == NULL || gbl->fbdev == info->dev;
- +}
- +
- +static const struct backlight_ops ocp8178_backlight_ops = {
- + .options = BL_CORE_SUSPENDRESUME,
- + .update_status = ocp8178_update_status,
- + .get_brightness = ocp8178_get_brightness,
- + .check_fb = ocp8178_check_fb,
- +};
- +
- +static int ocp8178_probe_dt(struct platform_device *pdev,
- + struct ocp8178_backlight *gbl)
- +{
- + struct device *dev = &pdev->dev;
- + struct device_node *np = dev->of_node;
- + enum gpiod_flags flags;
- + int ret = 0;
- + u32 value32;
- +
- + of_property_read_u32(np, "default-brightness", &value32);
- + if(value32 > MAX_BRIGHTNESS_VALUE)
- + gbl->def_value = MAX_BRIGHTNESS_VALUE;
- + else
- + gbl->def_value = value32;
- + flags = gbl->def_value ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
- +
- + gbl->gpiod = devm_gpiod_get(dev, "backlight-control", flags);
- + if (IS_ERR(gbl->gpiod)) {
- + ret = PTR_ERR(gbl->gpiod);
- +
- + if (ret != -EPROBE_DEFER) {
- + dev_err(dev,
- + "Error: The gpios parameter is missing or invalid.\n");
- + }
- + }
- +
- + return ret;
- +}
- +
- +static struct backlight_device *backlight;
- +
- +static int ocp8178_probe(struct platform_device *pdev)
- +{
- + struct backlight_properties props;
- + struct backlight_device *bl;
- + struct ocp8178_backlight *gbl;
- + struct device_node *np = pdev->dev.of_node;
- + int ret;
- +
- + if ( !np) {
- + dev_err(&pdev->dev,
- + "failed to find platform data or device tree node.\n");
- + return -ENODEV;
- + }
- +
- + gbl = devm_kzalloc(&pdev->dev, sizeof(*gbl), GFP_KERNEL);
- + if (gbl == NULL)
- + return -ENOMEM;
- +
- + gbl->dev = &pdev->dev;
- +
- + ret = ocp8178_probe_dt(pdev, gbl);
- + if (ret)
- + return ret;
- +
- + gbl->current_value = gbl->def_value;
- +
- + memset(&props, 0, sizeof(props));
- + props.type = BACKLIGHT_RAW;
- + props.max_brightness = MAX_BRIGHTNESS_VALUE;
- + bl = devm_backlight_device_register(&pdev->dev, dev_name(&pdev->dev),
- + &pdev->dev, gbl, &ocp8178_backlight_ops,
- + &props);
- + if (IS_ERR(bl)) {
- + dev_err(&pdev->dev, "failed to register backlight\n");
- + return PTR_ERR(bl);
- + }
- +
- +// entry_1wire_mode(gbl);
- +
- + bl->props.brightness = gbl->def_value;
- + backlight_update_status(bl);
- +
- + platform_set_drvdata(pdev, bl);
- +
- + backlight = bl;
- + return 0;
- +}
- +
- +static int ocp8178_suspend(struct platform_device *pdev, pm_message_t state)
- +{
- + return 0;
- +}
- +
- +static int ocp8178_resume(struct platform_device *pdev)
- +{
- + return 0;
- +}
- +
- +static struct of_device_id ocp8178_of_match[] = {
- + { .compatible = "ocp8178-backlight" },
- + { /* sentinel */ }
- +};
- +
- +MODULE_DEVICE_TABLE(of, ocp8178_of_match);
- +
- +static struct platform_driver ocp8178_driver = {
- + .driver = {
- + .name = "ocp8178-backlight",
- + .of_match_table = of_match_ptr(ocp8178_of_match),
- + },
- + .probe = ocp8178_probe,
- + .suspend = ocp8178_suspend,
- + .resume = ocp8178_resume,
- +};
- +
- +module_platform_driver(ocp8178_driver);
- +
- +MODULE_DESCRIPTION("OCP8178 Driver");
- +MODULE_LICENSE("GPL");
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