Re: [PATCH v2] Platform: Samsung Q10 backlight driver
From: Frederick van der Wyck
Date: Tue Feb 22 2011 - 16:26:56 EST
Hi Dmitry,
Thanks for the further comments.
> If it is a bool the call it so.
Fixed.
> Hmm, if samsungq10_bl_set_intensity() can indeed run simultaneously with
> suspend/resume then you'd need to protect it with spinlock or mutex.
I guess it's OK to assume samsungq10_bl_set_intensity() will not be called
during suspend/resume so I've removed the check.
> Don't you need to restore backlight when resuming from hibernate? I
> think you need to guard you methods with CONFIG_PM_SLEEP and then
> use SIMPLE_DEV_PM_OPS().
You're right, thanks, I've made the change.
> Samsung is way too generic for driver name, maybe call it
> KBUILD_MODNAME?
I changed it from "samsung-q10" to "samsung" in reponse to Greg's feedback,
but OK, I've made it KBUILD_MODNAME as you suggest.
Here's a new version of the patch.
Thanks,
Frederick
Signed-off-by: Frederick van der Wyck <fvanderwyck@xxxxxxxxx>
---
drivers/platform/x86/Kconfig | 7 ++
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/samsung-q10.c | 179 ++++++++++++++++++++++++++++++++++++
3 files changed, 187 insertions(+), 0 deletions(-)
create mode 100644 drivers/platform/x86/samsung-q10.c
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index faec777..c390727 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -639,4 +639,11 @@ config XO1_RFKILL
Support for enabling/disabling the WLAN interface on the OLPC XO-1
laptop.
+config SAMSUNG_Q10
+ tristate "Samsung Q10 Extras"
+ select BACKLIGHT_CLASS_DEVICE
+ ---help---
+ This driver provides support for backlight control on Samsung Q10
+ and some other laptops, including Dell Latitude X200.
+
endif # X86_PLATFORM_DEVICES
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 9950ccc..2cd3e52 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -33,3 +33,4 @@ obj-$(CONFIG_INTEL_IPS) += intel_ips.o
obj-$(CONFIG_GPIO_INTEL_PMIC) += intel_pmic_gpio.o
obj-$(CONFIG_XO1_RFKILL) += xo1-rfkill.o
obj-$(CONFIG_IBM_RTL) += ibm_rtl.o
+obj-$(CONFIG_SAMSUNG_Q10) += samsung-q10.o
diff --git a/drivers/platform/x86/samsung-q10.c b/drivers/platform/x86/samsung-q10.c
new file mode 100644
index 0000000..7b60c67
--- /dev/null
+++ b/drivers/platform/x86/samsung-q10.c
@@ -0,1 +1,179 @@
+/*
+ * Driver for Samsung Q10: controls the backlight
+ *
+ * Copyright (c) 2011 Frederick van der Wyck <fvanderwyck@xxxxxxxxx>
+ *
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/backlight.h>
+#include <linux/i8042.h>
+#include <linux/dmi.h>
+
+#define SAMSUNGQ10_BL_MAX_INTENSITY 255
+#define SAMSUNGQ10_BL_DEFAULT_INTENSITY 185
+
+#define SAMSUNGQ10_BL_8042_CMD 0xbe
+#define SAMSUNGQ10_BL_8042_DATA { 0x89, 0x91 }
+
+static int samsungq10_bl_brightness;
+
+static bool force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force,
+ "Disable the DMI check and force the driver to be loaded");
+
+static int samsungq10_bl_set_intensity(struct backlight_device *bd)
+{
+
+ int brightness = bd->props.brightness;
+ unsigned char c[3] = SAMSUNGQ10_BL_8042_DATA;
+
+ c[2] = (unsigned char)brightness;
+ i8042_lock_chip();
+ i8042_command(c, (0x30 << 8) | SAMSUNGQ10_BL_8042_CMD);
+ i8042_unlock_chip();
+ samsungq10_bl_brightness = brightness;
+
+ return 0;
+}
+
+static int samsungq10_bl_get_intensity(struct backlight_device *bd)
+{
+ return samsungq10_bl_brightness;
+}
+
+static const struct backlight_ops samsungq10_bl_ops = {
+ .get_brightness = samsungq10_bl_get_intensity,
+ .update_status = samsungq10_bl_set_intensity,
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int samsungq10_suspend(struct device *dev)
+{
+ return 0;
+}
+
+static int samsungq10_resume(struct device *dev)
+{
+
+ struct backlight_device *bd = dev_get_drvdata(dev);
+
+ samsungq10_bl_set_intensity(bd);
+ return 0;
+}
+#else
+#define samsungq10_suspend NULL
+#define samsungq10_resume NULL
+#endif
+
+static SIMPLE_DEV_PM_OPS(samsungq10_pm_ops,
+ samsungq10_suspend, samsungq10_resume);
+
+static int __devinit samsungq10_probe(struct platform_device *pdev)
+{
+
+ struct backlight_properties props;
+ struct backlight_device *bd;
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
+ bd = backlight_device_register("samsung", &pdev->dev, NULL,
+ &samsungq10_bl_ops, &props);
+ if (IS_ERR(bd))
+ return PTR_ERR(bd);
+
+ platform_set_drvdata(pdev, bd);
+
+ bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
+ samsungq10_bl_set_intensity(bd);
+
+ return 0;
+}
+
+static int __devexit samsungq10_remove(struct platform_device *pdev)
+{
+
+ struct backlight_device *bd = platform_get_drvdata(pdev);
+
+ bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
+ samsungq10_bl_set_intensity(bd);
+
+ backlight_device_unregister(bd);
+
+ return 0;
+}
+
+static struct platform_driver samsungq10_driver = {
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .owner = THIS_MODULE,
+ .pm = &samsungq10_pm_ops,
+ },
+ .probe = samsungq10_probe,
+ .remove = __devexit_p(samsungq10_remove),
+};
+
+static struct platform_device *samsungq10_device;
+
+static int __init dmi_check_callback(const struct dmi_system_id *id)
+{
+ printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
+ return 0;
+}
+
+static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
+ {
+ .ident = "Samsung Q10",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
+ },
+ .callback = dmi_check_callback,
+ },
+ {
+ .ident = "Dell Latitude X200",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
+ },
+ .callback = dmi_check_callback,
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
+
+static int __init samsungq10_init(void)
+{
+ if (!force && !dmi_check_system(samsungq10_dmi_table))
+ return -ENODEV;
+
+ samsungq10_device = platform_create_bundle(&samsungq10_driver,
+ samsungq10_probe,
+ NULL, 0, NULL, 0);
+
+ if (IS_ERR(samsungq10_device))
+ return PTR_ERR(samsungq10_device);
+
+ return 0;
+}
+
+static void __exit samsungq10_exit(void)
+{
+ platform_device_unregister(samsungq10_device);
+ platform_driver_unregister(&samsungq10_driver);
+}
+
+module_init(samsungq10_init);
+module_exit(samsungq10_exit);
+
+MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@xxxxxxxxx>");
+MODULE_DESCRIPTION("Samsung Q10 Driver");
+MODULE_LICENSE("GPL");
--
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