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Commit 5b80fc40 authored by Corentin Chary's avatar Corentin Chary Committed by Matthew Garrett
Browse files

samsung-laptop: add a small debugfs interface 



This allow to call arbitrary sabi commands wihout
modifying the driver at all. For example, setting
the keyboard backlight brightness to 5 using debugfs
interface can be done like that:

 ; Set the command
 echo 0x78 > command
 ; Set the data
 echo 0x0582 > d0
 ; Fill the rest with 0
 echo 0 > d1
 echo 0 > d2
 echo 0 > d3
 ; And issue the command
 cat call

Signed-off-by: default avatarCorentin Chary <corentincj@iksaif.net>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
parent 7e960711

drivers/platform/x86/samsung-laptop.c

+147 −0
Original line number Diff line number Diff line
@@ -22,6 +22,8 @@ 
#include <linux/platform_device.h>

#include <linux/rfkill.h>

#include <linux/acpi.h>

#include <linux/seq_file.h>

#include <linux/debugfs.h>



/*

 * This driver is needed because a number of Samsung laptops do not hook
@@ -226,6 +228,35 @@ static const struct sabi_config sabi_configs[] = { 
	{ },

};



/*

 * samsung-laptop/    - debugfs root directory

 *   f0000_segment    - dump f0000 segment

 *   command          - current command

 *   data             - current data

 *   d0, d1, d2, d3   - data fields

 *   call             - call SABI using command and data

 *

 * This allow to call arbitrary sabi commands wihout

 * modifying the driver at all.

 * For example, setting the keyboard backlight brightness to 5

 *

 *  echo 0x78 > command

 *  echo 0x0582 > d0

 *  echo 0 > d1

 *  echo 0 > d2

 *  echo 0 > d3

 *  cat call

 */



struct samsung_laptop_debug {

	struct dentry *root;

	struct sabi_data data;

	u16 command;



	struct debugfs_blob_wrapper f0000_wrapper;

	struct debugfs_blob_wrapper data_wrapper;

};



struct samsung_laptop {

	const struct sabi_config *config;
@@ -239,6 +270,8 @@ struct samsung_laptop { 
	struct backlight_device *backlight_device;

	struct rfkill *rfk;



	struct samsung_laptop_debug debug;



	bool handle_backlight;

	bool has_stepping_quirk;

};
@@ -680,6 +713,113 @@ static int __init samsung_sysfs_init(struct samsung_laptop *samsung) 


}



static int show_call(struct seq_file *m, void *data)

{

	struct samsung_laptop *samsung = m->private;

	struct sabi_data *sdata = &samsung->debug.data;

	int ret;



	seq_printf(m, "SABI 0x%04x {0x%08x, 0x%08x, 0x%04x, 0x%02x}\n",

		   samsung->debug.command,

		   sdata->d0, sdata->d1, sdata->d2, sdata->d3);



	ret = sabi_command(samsung, samsung->debug.command, sdata, sdata);



	if (ret) {

		seq_printf(m, "SABI command 0x%04x failed\n",

			   samsung->debug.command);

		return ret;

	}



	seq_printf(m, "SABI {0x%08x, 0x%08x, 0x%04x, 0x%02x}\n",

		   sdata->d0, sdata->d1, sdata->d2, sdata->d3);

	return 0;

}



static int samsung_debugfs_open(struct inode *inode, struct file *file)

{

	return single_open(file, show_call, inode->i_private);

}



static const struct file_operations samsung_laptop_call_io_ops = {

	.owner = THIS_MODULE,

	.open = samsung_debugfs_open,

	.read = seq_read,

	.llseek = seq_lseek,

	.release = single_release,

};



static void samsung_debugfs_exit(struct samsung_laptop *samsung)

{

	debugfs_remove_recursive(samsung->debug.root);

}



static int samsung_debugfs_init(struct samsung_laptop *samsung)

{

	struct dentry *dent;



	samsung->debug.root = debugfs_create_dir("samsung-laptop", NULL);

	if (!samsung->debug.root) {

		pr_err("failed to create debugfs directory");

		goto error_debugfs;

	}



	samsung->debug.f0000_wrapper.data = samsung->f0000_segment;

	samsung->debug.f0000_wrapper.size = 0xffff;



	samsung->debug.data_wrapper.data = &samsung->debug.data;

	samsung->debug.data_wrapper.size = sizeof(samsung->debug.data);



	dent = debugfs_create_u16("command", S_IRUGO | S_IWUSR,

				  samsung->debug.root, &samsung->debug.command);

	if (!dent)

		goto error_debugfs;



	dent = debugfs_create_u32("d0", S_IRUGO | S_IWUSR, samsung->debug.root,

				  &samsung->debug.data.d0);

	if (!dent)

		goto error_debugfs;



	dent = debugfs_create_u32("d1", S_IRUGO | S_IWUSR, samsung->debug.root,

				  &samsung->debug.data.d1);

	if (!dent)

		goto error_debugfs;



	dent = debugfs_create_u16("d2", S_IRUGO | S_IWUSR, samsung->debug.root,

				  &samsung->debug.data.d2);

	if (!dent)

		goto error_debugfs;



	dent = debugfs_create_u8("d3", S_IRUGO | S_IWUSR, samsung->debug.root,

				 &samsung->debug.data.d3);

	if (!dent)

		goto error_debugfs;



	dent = debugfs_create_blob("data", S_IRUGO | S_IWUSR,

				   samsung->debug.root,

				   &samsung->debug.data_wrapper);

	if (!dent)

		goto error_debugfs;



	dent = debugfs_create_blob("f0000_segment", S_IRUSR | S_IWUSR,

				   samsung->debug.root,

				   &samsung->debug.f0000_wrapper);

	if (!dent)

		goto error_debugfs;



	dent = debugfs_create_file("call", S_IFREG | S_IRUGO,

				   samsung->debug.root, samsung,

				   &samsung_laptop_call_io_ops);

	if (!dent)

		goto error_debugfs;



	return 0;



error_debugfs:

	samsung_debugfs_exit(samsung);

	return -ENOMEM;

}



static void samsung_sabi_exit(struct samsung_laptop *samsung)

{

	const struct sabi_config *config = samsung->config;
@@ -1123,9 +1263,15 @@ static int __init samsung_init(void) 
	if (ret)

		goto error_rfkill;



	ret = samsung_debugfs_init(samsung);

	if (ret)

		goto error_debugfs;



	samsung_platform_device = samsung->platform_device;

	return ret;



error_debugfs:

	samsung_rfkill_exit(samsung);

error_rfkill:

	samsung_backlight_exit(samsung);

error_backlight:
@@ -1145,6 +1291,7 @@ static void __exit samsung_exit(void) 


	samsung = platform_get_drvdata(samsung_platform_device);



	samsung_debugfs_exit(samsung);

	samsung_rfkill_exit(samsung);

	samsung_backlight_exit(samsung);

	samsung_sysfs_exit(samsung);