On Tuesday, October 28, 2014 9:02 AM, Dmitry Eremin-Solenikov wrote:
>
> Add new simple backlight driver - it cares only about PWM/frontlight
> part of LoCoMo, it does not touch TFT settings and does not export TFT
> power control.
>
> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
> ---
> drivers/video/backlight/Kconfig | 6 +-
> drivers/video/backlight/Makefile | 2 +-
> drivers/video/backlight/locomo_bl.c | 171 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 175 insertions(+), 4 deletions(-)
> create mode 100644 drivers/video/backlight/locomo_bl.c
>
> diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
> index 8d03924..03b77b33 100644
> --- a/drivers/video/backlight/Kconfig
> +++ b/drivers/video/backlight/Kconfig
> @@ -218,12 +218,12 @@ config BACKLIGHT_LM3533
> levels.
>
> config BACKLIGHT_LOCOMO
> - tristate "Sharp LOCOMO LCD/Backlight Driver"
> - depends on SHARP_LOCOMO
> + tristate "Sharp LOCOMO Backlight Driver"
> + depends on MFD_LOCOMO
> default y
> help
> If you have a Sharp Zaurus SL-5500 (Collie) or SL-5600 (Poodle) say y to
> - enable the LCD/backlight driver.
> + enable the backlight driver.
>
> config BACKLIGHT_OMAP1
> tristate "OMAP1 PWL-based LCD Backlight"
> diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
> index fcd50b73..2a61b7e 100644
> --- a/drivers/video/backlight/Makefile
> +++ b/drivers/video/backlight/Makefile
> @@ -39,7 +39,7 @@ obj-$(CONFIG_BACKLIGHT_IPAQ_MICRO) += ipaq_micro_bl.o
> obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o
> obj-$(CONFIG_BACKLIGHT_LM3630A) += lm3630a_bl.o
> obj-$(CONFIG_BACKLIGHT_LM3639) += lm3639_bl.o
> -obj-$(CONFIG_BACKLIGHT_LOCOMO) += locomolcd.o
> +obj-$(CONFIG_BACKLIGHT_LOCOMO) += locomo_bl.o
> obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o
> obj-$(CONFIG_BACKLIGHT_LP8788) += lp8788_bl.o
> obj-$(CONFIG_BACKLIGHT_LV5207LP) += lv5207lp.o
> diff --git a/drivers/video/backlight/locomo_bl.c b/drivers/video/backlight/locomo_bl.c
> new file mode 100644
> index 0000000..cec1b51
> --- /dev/null
> +++ b/drivers/video/backlight/locomo_bl.c
> @@ -0,0 +1,171 @@
> +/*
> + * Backlight control code for Sharp Zaurus SL-5500
> + *
> + * Copyright 2005 John Lenz <lenz@xxxxxxxxxxx>
> + * Maintainer: Pavel Machek <pavel@xxxxxx> (unless John wants to :-)
> + * GPL v2
> + *
> + * This driver assumes single CPU. That's okay, because collie is
> + * slightly old hardware, and no one is going to retrofit second CPU to
> + * old PDA.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/platform_device.h>
> +#include <linux/fb.h>
> +#include <linux/backlight.h>
> +#include <linux/err.h>
> +#include <linux/gpio.h>
> +#include <linux/delay.h>
> +#include <linux/mfd/locomo.h>
Please, re-order these headers alphabetically.
It enhances the readability.
> +
> +struct locomo_bl {
> + void __iomem *regs;
> + int current_intensity;
> + int gpio_fl_vr;
> +};
> +
> +static const struct {
> + u16 duty, bpwf;
> + bool vr;
> +} locomo_bl_pwm[] = {
> + { 0, 161, false },
> + { 117, 161, false },
> + { 163, 148, false },
> + { 194, 161, false },
> + { 194, 161, true },
> +};
> +
> +static int locomo_bl_set_intensity(struct backlight_device *bd)
> +{
> + int intensity = bd->props.brightness;
> + struct locomo_bl *bl = dev_get_drvdata(&bd->dev);
> +
> + if (bd->props.power != FB_BLANK_UNBLANK)
> + intensity = 0;
> + if (bd->props.fb_blank != FB_BLANK_UNBLANK)
> + intensity = 0;
> + if (bd->props.state & BL_CORE_SUSPENDED)
> + intensity = 0;
> +
> + gpio_set_value(bl->gpio_fl_vr, locomo_bl_pwm[intensity].vr);
> +
> + writew(locomo_bl_pwm[intensity].bpwf, bl->regs + LOCOMO_ALS);
> + udelay(100);
> + writew(locomo_bl_pwm[intensity].duty, bl->regs + LOCOMO_ALD);
> + udelay(100);
How about changing udelay() to usleep_range()?
> + writew(locomo_bl_pwm[intensity].bpwf | LOCOMO_ALC_EN,
> + bl->regs + LOCOMO_ALS);
> +
> + bl->current_intensity = intensity;
> + if (bd->props.state & BL_CORE_SUSPENDED)
> + writew(0x00, bl->regs + LOCOMO_ALS);
> +
> + return 0;
> +}
> +
> +static int locomo_bl_get_intensity(struct backlight_device *bd)
> +{
> + struct locomo_bl *bl = dev_get_drvdata(&bd->dev);
> +
> + return bl->current_intensity;
> +}
> +
> +static const struct backlight_ops locomo_bl_ops = {
> + .options = BL_CORE_SUSPENDRESUME,
> + .get_brightness = locomo_bl_get_intensity,
> + .update_status = locomo_bl_set_intensity,
> +};
> +
> +static int locomo_bl_probe(struct platform_device *dev)
> +{
> + struct backlight_properties props;
> + struct resource *res;
> + struct locomo_bl_platform_data *pdata;
> + struct locomo_bl *bl;
> + struct backlight_device *locomo_bl_device;
> + int rc;
> +
> + bl = devm_kmalloc(&dev->dev, sizeof(struct locomo_bl), GFP_KERNEL);
> + if (!bl)
> + return -ENOMEM;
> +
> + res = platform_get_resource(dev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -EINVAL;
There is no need to check this, because devm_ioremap_resource()
will check this.
> + bl->regs = devm_ioremap_resource(&dev->dev, res);
> + if (!bl->regs)
> + return -EINVAL;
The correct usage is as follows.
if (IS_ERR(base))
return PTR_ERR(base);
Please change it as below.
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
bl->regs = devm_ioremap_resource(&dev->dev, res);
if (IS_ERR(bl->regs))
return PTR_ERR(bl->regs);
> +
> + pdata = dev_get_platdata(&dev->dev);
> + if (!pdata)
> + return -EINVAL;
> +
> + bl->gpio_fl_vr = pdata->gpio_fl_vr;
> + rc = devm_gpio_request_one(&dev->dev, bl->gpio_fl_vr,
> + GPIOF_OUT_INIT_LOW, "FL VR");
> + if (rc)
> + return rc;
> +
> + writew(0, bl->regs + LOCOMO_ALS);
> + writew(0, bl->regs + LOCOMO_ALD);
> +
> + memset(&props, 0, sizeof(struct backlight_properties));
> + props.type = BACKLIGHT_RAW;
> + props.max_brightness = ARRAY_SIZE(locomo_bl_pwm) - 1;
> + props.brightness = props.max_brightness / 2;
> + locomo_bl_device = backlight_device_register("locomo-bl",
Please use devm_backlight_device_register().
> + &dev->dev, bl,
> + &locomo_bl_ops, &props);
> +
> + if (IS_ERR(locomo_bl_device))
> + return PTR_ERR(locomo_bl_device);
> +
> + platform_set_drvdata(dev, locomo_bl_device);
> +
> + /* Set up frontlight so that screen is readable */
> + backlight_update_status(locomo_bl_device);
> +
> + return 0;
> +}
> +
> +static int locomo_bl_remove(struct platform_device *dev)
> +{
> + struct backlight_device *locomo_bl_device = platform_get_drvdata(dev);
> +
> + locomo_bl_device->props.brightness = 0;
> + locomo_bl_device->props.power = 0;
> + locomo_bl_set_intensity(locomo_bl_device);
> +
> + backlight_device_unregister(locomo_bl_device);
If devm_backlight_device_register() is used in probe(),
there is no need to call backlight_device_unregister() in remove().
> +
> + return 0;
> +}
> +
> +static void locomo_bl_shutdown(struct platform_device *dev)
> +{
> + struct backlight_device *locomo_bl_device = platform_get_drvdata(dev);
> +
> + locomo_bl_device->props.brightness = 0;
> + locomo_bl_device->props.power = 0;
> + locomo_bl_set_intensity(locomo_bl_device);
> +}
> +
> +static struct platform_driver locomo_bl_driver = {
> + .driver = {
> + .name = "locomo-backlight",
> + .owner = THIS_MODULE,
> + },
> + .probe = locomo_bl_probe,
> + .remove = locomo_bl_remove,
> + /* Turn off bl on power off/reboot */
> + .shutdown = locomo_bl_shutdown,
> +};
> +
> +module_platform_driver(locomo_bl_driver);
> +
> +MODULE_AUTHOR("John Lenz <lenz@xxxxxxxxxxx>, Pavel Machek <pavel@xxxxxx>");
This might make checkpatch warning.
Please split these authors to lines as below.
MODULE_AUTHOR("John Lenz <lenz@xxxxxxxxxxx>");
MODULE_AUTHOR("Pavel Machek <pavel@xxxxxx>");
> +MODULE_DESCRIPTION("Collie Backlight driver");
What does mean 'Collie'? 'Locomo' looks better.
> +MODULE_LICENSE("GPL");
How about using "GPL v2"?
Thank you.
Best regards,
Jingoo Han
> +MODULE_ALIAS("platform:locomo-backlight");
> --
> 2.1.1
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