[Intel-gfx] New Samsung driver for backlight control.
Mike Lothian
mike at fireburn.co.uk
Sat Aug 22 11:27:58 CEST 2009
2009/8/22 Greg KH <greg at kroah.com>:
> On Sat, Aug 15, 2009 at 01:33:13PM +0100, Mike Lothian wrote:
>> This is great news guys, hopefully I'll finally be able to control the
>> screen brightness of my GM45 in my Samsung R510
>
> Ok, as the testing with you and Jesse proved, your BIOS really is
> reporting that you shouldn't be mucking around with "raw" pci config
> read/write.
>
> I've now rewritten the Samsung driver to talk through the BIOS, thanks
> to some information that someone has forwarded on to me.
>
> It would be great if you could test this patch out to see if it works
> for your machine or not.
>
> You will need to load the driver with the force=1 setting set, as it
> does not have your DMI values in it.
>
> If you do:
> modprobe samsung-laptop force=1
> and let me know what the kernel log reports, that would be wonderful.
>
> thanks,
>
> greg k-h
>
> ---------------
>
> From: Greg Kroah-Hartman <gregkh at suse.de>
> Subject: Samsung laptop driver
>
> This driver implements backlight controls for Samsung laptops that
> currently do not have ACPI support for this control.
>
> It has been tested on the N130 laptop and properly works there.
>
> Many thanks to Dmitry Torokhov <dmitry.torokhov at gmail.com> for cleanups
> and other suggestions on how to make the driver simpler.
>
> Cc: Soeren Sonnenburg <bugreports at nn7.de>
> Cc: Jérémie Huchet <jeremie at lamah.info>
> Cc: Dmitry Torokhov <dmitry.torokhov at gmail.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>
>
> ---
> drivers/platform/x86/Kconfig | 12
> drivers/platform/x86/Makefile | 1
> drivers/platform/x86/samsung-laptop.c | 420 ++++++++++++++++++++++++++++++++++
> 3 files changed, 433 insertions(+)
>
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -425,4 +425,16 @@ config ACPI_TOSHIBA
>
> If you have a legacy free Toshiba laptop (such as the Libretto L1
> series), say Y.
> +
> +config SAMSUNG_LAPTOP
> + tristate "Samsung Laptop driver"
> + depends on BACKLIGHT_CLASS_DEVICE
> + depends on DMI
> + ---help---
> + This driver adds support to control the backlight on a number of
> + Samsung laptops, like the N130, and control for some of the LEDs
> +
> + It will only be loaded on laptops that properly need it, so it is
> + safe to say Y here.
> +
> endif # X86_PLATFORM_DEVICES
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -20,3 +20,4 @@ obj-$(CONFIG_INTEL_MENLOW) += intel_menl
> obj-$(CONFIG_ACPI_WMI) += wmi.o
> obj-$(CONFIG_ACPI_ASUS) += asus_acpi.o
> obj-$(CONFIG_ACPI_TOSHIBA) += toshiba_acpi.o
> +obj-$(CONFIG_SAMSUNG_LAPTOP) += samsung-laptop.o
> --- /dev/null
> +++ b/drivers/platform/x86/samsung-laptop.c
> @@ -0,0 +1,420 @@
> +/*
> + * Samsung N130 and NC120 Laptop driver
> + *
> + * Copyright (C) 2009 Greg Kroah-Hartman (gregkh at suse.de)
> + * Copyright (C) 2009 Novell Inc.
> + *
> + * 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/kernel.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/backlight.h>
> +#include <linux/fb.h>
> +#include <linux/dmi.h>
> +#include <linux/platform_device.h>
> +
> +/*
> + * This driver is needed because a number of Samsung laptops do not hook
> + * their control settings through ACPI. So we have to poke around in the
> + * BIOS to do things like brightness values, and "special" key controls.
> + */
> +
> +
> +/*
> + * We have 0 - 8 as valid brightness levels. The specs say that level 0 should
> + * be reserved by the BIOS (which really doesn't make much sense), we tell
> + * userspace that the value is 0 - 7 and then just tell the hardware 1 - 8
> + */
> +#define MAX_BRIGHT 0x07
> +
> +/* get model returns 4 characters that describe the model of the laptop */
> +#define SABI_GET_MODEL 0x04
> +
> +/* Brightness is 0 - 8, as described above. Value 0 is for the BIOS to use */
> +#define SABI_GET_BRIGHTNESS 0x10
> +#define SABI_SET_BRIGHTNESS 0x11
> +
> +/* 0 is off, 1 is on, and 2 is a second user-defined key? */
> +#define SABI_GET_WIRELESS_BUTTON 0x12
> +#define SABI_SET_WIRELESS_BUTTON 0x13
> +
> +/* Temperature is returned in degress Celsius from what I can guess. */
> +#define SABI_GET_CPU_TEMP 0x29
> +
> +/* 0 is off, 1 is on. Doesn't seem to work on a N130 for some reason */
> +#define SABI_GET_BACKLIGHT 0x2d
> +#define SABI_SET_BACKLIGHT 0x2e
> +
> +/*
> + * This is different
> + * There is 3 different modes here:
> + * 0 - off
> + * 1 - on
> + * 2 - max performance mode
> + * off is "normal" mode.
> + * on means that whatever the bios setting for etiquette mode, is enabled. It
> + * seems that the BIOS can set either "auto" mode, or "slow" mode. If "slow"
> + * mode is set, the fan turns off, and the cpu is throttled down to not cause
> + * the fan to turn on if at all possible.
> + * max performance means that the processor can be overclocked and run faster
> + * then is physically possible. Ok, maybe not physically possible, but it is
> + * overclocked. Funny that the system has a setting for this...
> + */
> +#define SABI_GET_ETIQUETTE_MODE 0x31
> +#define SABI_SET_ETIQUETTE_MODE 0x32
> +
> +/*
> + * I imagine that on some laptops there is a bluetooth switch, but I don't know
> + * what that looks like, or where it is in the BIOS address space
> + */
> +
> +
> +/*
> + * SABI HEADER in low memory (f0000)
> + * We need to poke through memory to find a signature in order to find the
> + * exact location of this structure.
> + */
> +struct sabi_header {
> + u16 portNo;
> + u8 ifaceFunc;
> + u8 enMem;
> + u8 reMem;
> + u16 dataOffset;
> + u16 dataSegment;
> + u8 BIOSifver;
> + u8 LauncherString;
> +} __attribute__((packed));
> +
> +/*
> + * The SABI interface that we use to write and read values from the system.
> + * It is found by looking at the dataOffset and dataSegment values in the sabi
> + * header structure
> + */
> +struct sabi_interface {
> + u16 mainfunc;
> + u16 subfunc;
> + u8 complete;
> + u8 retval[20];
> +} __attribute__((packed));
> +
> +/* Structure to get data back to the calling function */
> +struct sabi_retval {
> + u8 retval[20];
> +};
> +
> +static struct sabi_header __iomem *sabi;
> +static struct sabi_interface __iomem *sabi_iface;
> +static void __iomem *f0000_segment;
> +static struct backlight_device *backlight_device;
> +static struct mutex sabi_mutex;
> +static struct platform_device *sdev;
> +
> +static int force;
> +module_param(force, bool, 0);
> +MODULE_PARM_DESC(force, "Disable the DMI check and forces the driver to be loaded");
> +
> +static int debug;
> +module_param(debug, bool, S_IRUGO | S_IWUSR);
> +MODULE_PARM_DESC(debug, "Debug enabled or not");
> +
> +static int sabi_get_command(u8 command, struct sabi_retval *sretval)
> +{
> + int retval = 0;
> +
> + mutex_lock(&sabi_mutex);
> +
> + /* enable memory to be able to write to it */
> + outb(readb(&sabi->enMem), readw(&sabi->portNo));
> +
> + /* write out the command */
> + writew(0x5843, &sabi_iface->mainfunc);
> + writew(command, &sabi_iface->subfunc);
> + writeb(0, &sabi_iface->complete);
> + outb(readb(&sabi->ifaceFunc), readw(&sabi->portNo));
> +
> + /* sleep for a bit to let the command complete */
> + msleep(100);
> +
> + /* write protect memory to make it safe */
> + outb(readb(&sabi->reMem), readw(&sabi->portNo));
> +
> + /* see if the command actually succeeded */
> + if (readb(&sabi_iface->complete) == 0xaa &&
> + readb(&sabi_iface->retval[0]) != 0xff) {
> + /*
> + * It did!
> + * Save off the data into a structure so the caller use it.
> + * Right now we only care about the first 4 bytes,
> + * I suppose there are commands that need more, but I don't
> + * know about them.
> + */
> + sretval->retval[0] = readb(&sabi_iface->retval[0]);
> + sretval->retval[1] = readb(&sabi_iface->retval[1]);
> + sretval->retval[2] = readb(&sabi_iface->retval[2]);
> + sretval->retval[3] = readb(&sabi_iface->retval[3]);
> + goto exit;
> + }
> +
> + /* Something bad happened, so report it and error out */
> + printk(KERN_WARNING "SABI command 0x%02x failed with completion flag 0x%02x and output 0x%02x\n",
> + command, readb(&sabi_iface->complete),
> + readb(&sabi_iface->retval[0]));
> + retval = -EINVAL;
> +exit:
> + mutex_unlock(&sabi_mutex);
> + return retval;
> +
> +}
> +
> +static int sabi_set_command(u8 command, u8 data)
> +{
> + int retval = 0;
> +
> + mutex_lock(&sabi_mutex);
> +
> + /* enable memory to be able to write to it */
> + outb(readb(&sabi->enMem), readw(&sabi->portNo));
> +
> + /* write out the command */
> + writew(0x5843, &sabi_iface->mainfunc);
> + writew(command, &sabi_iface->subfunc);
> + writeb(0, &sabi_iface->complete);
> + writeb(data, &sabi_iface->retval[0]);
> + outb(readb(&sabi->ifaceFunc), readw(&sabi->portNo));
> +
> + /* sleep for a bit to let the command complete */
> + msleep(100);
> +
> + /* write protect memory to make it safe */
> + outb(readb(&sabi->reMem), readw(&sabi->portNo));
> +
> + /* see if the command actually succeeded */
> + if (readb(&sabi_iface->complete) == 0xaa &&
> + readb(&sabi_iface->retval[0]) != 0xff) {
> + /* it did! */
> + goto exit;
> + }
> +
> + /* Something bad happened, so report it and error out */
> + printk(KERN_WARNING "SABI command 0x%02x failed with completion flag 0x%02x and output 0x%02x\n",
> + command, readb(&sabi_iface->complete),
> + readb(&sabi_iface->retval[0]));
> + retval = -EINVAL;
> +exit:
> + mutex_unlock(&sabi_mutex);
> + return retval;
> +}
> +
> +static u8 read_brightness(void)
> +{
> + struct sabi_retval sretval;
> + int user_brightness = 0;
> + int retval;
> +
> + retval = sabi_get_command(SABI_GET_BACKLIGHT, &sretval);
> + if (!retval)
> + user_brightness = sretval.retval[0];
> + if (user_brightness != 0)
> + --user_brightness;
> + return user_brightness;
> +}
> +
> +static void set_brightness(u8 user_brightness)
> +{
> + sabi_set_command(SABI_SET_BRIGHTNESS, user_brightness + 1);
> +}
> +
> +static int get_brightness(struct backlight_device *bd)
> +{
> + return bd->props.brightness;
> +}
> +
> +static int update_status(struct backlight_device *bd)
> +{
> + set_brightness(bd->props.brightness);
> + return 0;
> +}
> +
> +static struct backlight_ops backlight_ops = {
> + .get_brightness = get_brightness,
> + .update_status = update_status,
> +};
> +
> +static int __init dmi_check_cb(const struct dmi_system_id *id)
> +{
> + printk(KERN_INFO KBUILD_MODNAME ": found laptop model '%s'\n",
> + id->ident);
> + return 0;
> +}
> +
> +static struct dmi_system_id __initdata samsung_dmi_table[] = {
> + {
> + .ident = "N120",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
> + DMI_MATCH(DMI_PRODUCT_NAME, "N120"),
> + DMI_MATCH(DMI_BOARD_NAME, "N120"),
> + },
> + .callback = dmi_check_cb,
> + },
> + {
> + .ident = "N130",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
> + DMI_MATCH(DMI_PRODUCT_NAME, "N130"),
> + DMI_MATCH(DMI_BOARD_NAME, "N130"),
> + },
> + .callback = dmi_check_cb,
> + },
> + { },
> +};
> +
> +
> +static int __init samsung_init(void)
> +{
> + struct sabi_retval sretval;
> + const char *testStr = "SwSmi@";
> + void __iomem *memcheck;
> + unsigned int ifaceP;
> + int pStr;
> + int loca;
> + int retval;
> +
> + mutex_init(&sabi_mutex);
> +
> + if (!force && !dmi_check_system(samsung_dmi_table))
> + return -ENODEV;
> +
> + f0000_segment = ioremap(0xf0000, 0xffff);
> + if (!f0000_segment) {
> + printk(KERN_ERR "Can't map the segment at 0xf0000\n");
> + return -EINVAL;
> + }
> +
> + /* Try to find the signature "SwSmi@" in memory to find the header */
> + pStr = 0;
> + memcheck = f0000_segment;
> + for (loca = 0; loca < 0xffff; loca++) {
> + char temp = readb(memcheck + loca);
> +
> + if (temp == testStr[pStr]) {
> + if (pStr == 5)
> + break;
> + ++pStr;
> + } else {
> + pStr = 0;
> + }
> + }
> + if (loca == 0xffff) {
> + printk(KERN_INFO "This computer does not support SABI\n");
> + goto error_no_signature;
> + }
> +
> + /* point to the SMI port Number */
> + loca += 1;
> + sabi = (struct sabi_header __iomem *)(loca + memcheck);
> + if (!sabi) {
> + printk(KERN_ERR "Can't remap %p\n", loca + memcheck);
> + goto exit;
> + }
> +
> + printk(KERN_INFO "This computer supports SABI==%x\n", loca + 0xf0000 - 6);
> + printk(KERN_INFO "SABI header:\n");
> + printk(KERN_INFO " SMI Port Number = 0x%04x\n", readw(&sabi->portNo));
> + printk(KERN_INFO " SMI Interface Function = 0x%02x\n", readb(&sabi->ifaceFunc));
> + printk(KERN_INFO " SMI enable memory buffer = 0x%02x\n", readb(&sabi->enMem));
> + printk(KERN_INFO " SMI restore memory buffer = 0x%02x\n", readb(&sabi->reMem));
> + printk(KERN_INFO " SABI data offset = 0x%04x\n", readw(&sabi->dataOffset));
> + printk(KERN_INFO " SABI data segment = 0x%04x\n", readw(&sabi->dataSegment));
> + printk(KERN_INFO " BIOS interface version = 0x%02x\n", readb(&sabi->BIOSifver));
> + printk(KERN_INFO " KBD Launcher string = 0x%02x\n", readb(&sabi->LauncherString));
> +
> + /* Get a pointer to the SABI Interface */
> + ifaceP = (readw(&sabi->dataSegment) & 0x0ffff) << 4;
> + ifaceP += readw(&sabi->dataOffset) & 0x0ffff;
> + sabi_iface = (struct sabi_interface __iomem *)ioremap(ifaceP, 16);
> + if (!sabi_iface) {
> + printk(KERN_ERR "Can't remap %x\n", ifaceP);
> + goto exit;
> + }
> + printk(KERN_INFO "SABI Interface = %p\n", sabi_iface);
> +
> + retval = sabi_get_command(SABI_GET_MODEL, &sretval);
> + if (!retval) {
> + printk(KERN_INFO "Model Name %c%c%c%c\n",
> + sretval.retval[0],
> + sretval.retval[1],
> + sretval.retval[2],
> + sretval.retval[3]);
> + }
> +
> + retval = sabi_get_command(SABI_GET_BACKLIGHT, &sretval);
> + if (!retval)
> + printk("backlight = 0x%02x\n", sretval.retval[0]);
> +
> + retval = sabi_get_command(SABI_GET_WIRELESS_BUTTON, &sretval);
> + if (!retval)
> + printk("wireless button = 0x%02x\n", sretval.retval[0]);
> +
> + retval = sabi_get_command(SABI_GET_BRIGHTNESS, &sretval);
> + if (!retval)
> + printk("brightness = 0x%02x\n", sretval.retval[0]);
> +
> + retval = sabi_get_command(SABI_GET_ETIQUETTE_MODE, &sretval);
> + if (!retval)
> + printk("etiquette mode = 0x%02x\n", sretval.retval[0]);
> + retval = sabi_get_command(SABI_GET_CPU_TEMP, &sretval);
> + if (!retval)
> + printk("cpu temp = 0x%02x\n", sretval.retval[0]);
> +
> + /* knock up a platform device to hang stuff off of */
> + sdev = platform_device_register_simple("samsung", -1, NULL, 0);
> + if (IS_ERR(sdev))
> + goto error_no_platform;
> +
> + /* create a backlight device to talk to this one */
> + backlight_device = backlight_device_register("samsung", &sdev->dev,
> + NULL, &backlight_ops);
> + if (IS_ERR(backlight_device))
> + goto error_no_backlight;
> +
> + backlight_device->props.max_brightness = MAX_BRIGHT;
> + backlight_device->props.brightness = read_brightness();
> + backlight_device->props.power = FB_BLANK_UNBLANK;
> + backlight_update_status(backlight_device);
> +
> +exit:
> + return 0;
> +
> +error_no_backlight:
> + platform_device_unregister(sdev);
> +
> +error_no_platform:
> + iounmap(sabi_iface);
> +
> +error_no_signature:
> + iounmap(f0000_segment);
> + return -EINVAL;
> +}
> +
> +static void __exit samsung_exit(void)
> +{
> + backlight_device_unregister(backlight_device);
> + iounmap(sabi_iface);
> + iounmap(f0000_segment);
> + platform_device_unregister(sdev);
> +}
> +
> +module_init(samsung_init);
> +module_exit(samsung_exit);
> +
> +MODULE_AUTHOR("Greg Kroah-Hartman <gregkh at suse.de>");
> +MODULE_DESCRIPTION("Samsung Backlight driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("dmi:*:svnSAMSUNGELECTRONICSCO.,LTD.:pnN120:*:rnN120:*");
> +MODULE_ALIAS("dmi:*:svnSAMSUNGELECTRONICSCO.,LTD.:pnN130:*:rnN130:*");
>
I can confirm that it works however it does have different behaviour
At the lowest setting the backlight is still on and the screen even
though dull is still readable with the previous patch the screen was
black
This is what it says in my dmesg:
This computer supports SABI==f494d
SABI header:
SMI Port Number = 0x00b2
SMI Interface Function = 0xc0
SMI enable memory buffer = 0xc1
SMI restore memory buffer = 0xc2
SABI data offset = 0x0f00
SABI data segment = 0xdf01
BIOS interface version = 0x32
KBD Launcher string = 0x53
SABI Interface = ffff8800000dff10
Model Name R510
backlight = 0x01
wireless button = 0x01
brightness = 0x08
etiquette mode = 0x00
cpu temp = 0x45
Do you have any idea why my brightness buttons aren't working correctly?
Thanks for you help with this
Mike
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