Commit 96ff7056 authored by Matthew Garrett's avatar Matthew Garrett
Browse files

apple_gmux: Add support for newer hardware 



New gmux devices have a different method for accessing the registers.
Update the driver to cope. Incorporates feedback from Bernhard Froemel.

Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
Cc: Bernhard Froemel <froemel@vmars.tuwien.ac.at>
Cc: Seth Forshee <seth.forshee@canonical.com>
parent 7e30ed6b

drivers/platform/x86/apple-gmux.c

+165 −14
Original line number Diff line number Diff line
@@ -18,12 +18,15 @@ 
#include <linux/pnp.h>

#include <linux/apple_bl.h>

#include <linux/slab.h>

#include <linux/delay.h>

#include <acpi/video.h>

#include <asm/io.h>



struct apple_gmux_data {

	unsigned long iostart;

	unsigned long iolen;

	bool indexed;

	struct mutex index_lock;



	struct backlight_device *bdev;

};
@@ -45,6 +48,9 @@ struct apple_gmux_data { 
#define GMUX_PORT_DISCRETE_POWER	0x50

#define GMUX_PORT_MAX_BRIGHTNESS	0x70

#define GMUX_PORT_BRIGHTNESS		0x74

#define GMUX_PORT_VALUE			0xc2

#define GMUX_PORT_READ			0xd0

#define GMUX_PORT_WRITE			0xd4



#define GMUX_MIN_IO_LEN			(GMUX_PORT_BRIGHTNESS + 4)
@@ -59,23 +65,23 @@ struct apple_gmux_data { 
#define GMUX_BRIGHTNESS_MASK		0x00ffffff

#define GMUX_MAX_BRIGHTNESS		GMUX_BRIGHTNESS_MASK



static inline u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)

static u8 gmux_pio_read8(struct apple_gmux_data *gmux_data, int port)

{

	return inb(gmux_data->iostart + port);

}



static inline void gmux_write8(struct apple_gmux_data *gmux_data, int port,

static void gmux_pio_write8(struct apple_gmux_data *gmux_data, int port,

			       u8 val)

{

	outb(val, gmux_data->iostart + port);

}



static inline u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)

static u32 gmux_pio_read32(struct apple_gmux_data *gmux_data, int port)

{

	return inl(gmux_data->iostart + port);

}



static inline u32 gmux_write32(struct apple_gmux_data *gmux_data, int port,

static void gmux_pio_write32(struct apple_gmux_data *gmux_data, int port,

			     u32 val)

{

	int i;
@@ -87,6 +93,144 @@ static inline u32 gmux_write32(struct apple_gmux_data *gmux_data, int port, 
	}

}



static int gmux_index_wait_ready(struct apple_gmux_data *gmux_data)

{

	int i = 200;

	u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);



	while (i && (gwr & 0x01)) {

		inb(gmux_data->iostart + GMUX_PORT_READ);

		gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);

		udelay(100);

		i--;

	}



	return !!i;

}



static int gmux_index_wait_complete(struct apple_gmux_data *gmux_data)

{

	int i = 200;

	u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);



	while (i && !(gwr & 0x01)) {

		gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);

		udelay(100);

		i--;

	}



	if (gwr & 0x01)

		inb(gmux_data->iostart + GMUX_PORT_READ);



	return !!i;

}



static u8 gmux_index_read8(struct apple_gmux_data *gmux_data, int port)

{

	u8 val;



	mutex_lock(&gmux_data->index_lock);

	outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);

	gmux_index_wait_ready(gmux_data);

	val = inb(gmux_data->iostart + GMUX_PORT_VALUE);

	mutex_unlock(&gmux_data->index_lock);



	return val;

}



static void gmux_index_write8(struct apple_gmux_data *gmux_data, int port,

			      u8 val)

{

	mutex_lock(&gmux_data->index_lock);

	outb(val, gmux_data->iostart + GMUX_PORT_VALUE);

	gmux_index_wait_ready(gmux_data);

	outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);

	gmux_index_wait_complete(gmux_data);

	mutex_unlock(&gmux_data->index_lock);

}



static u32 gmux_index_read32(struct apple_gmux_data *gmux_data, int port)

{

	u32 val;



	mutex_lock(&gmux_data->index_lock);

	outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);

	gmux_index_wait_ready(gmux_data);

	val = inl(gmux_data->iostart + GMUX_PORT_VALUE);

	mutex_unlock(&gmux_data->index_lock);



	return val;

}



static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,

			       u32 val)

{

	int i;

	u8 tmpval;



	mutex_lock(&gmux_data->index_lock);



	for (i = 0; i < 4; i++) {

		tmpval = (val >> (i * 8)) & 0xff;

		outb(tmpval, gmux_data->iostart + GMUX_PORT_VALUE + i);

	}



	gmux_index_wait_ready(gmux_data);

	outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);

	gmux_index_wait_complete(gmux_data);

	mutex_unlock(&gmux_data->index_lock);

}



static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)

{

	if (gmux_data->indexed)

		return gmux_index_read8(gmux_data, port);

	else

		return gmux_pio_read8(gmux_data, port);

}



static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val)

{

	if (gmux_data->indexed)

		gmux_index_write8(gmux_data, port, val);

	else

		gmux_pio_write8(gmux_data, port, val);

}



static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)

{

	if (gmux_data->indexed)

		return gmux_index_read32(gmux_data, port);

	else

		return gmux_pio_read32(gmux_data, port);

}



static void gmux_write32(struct apple_gmux_data *gmux_data, int port,

			     u32 val)

{

	if (gmux_data->indexed)

		gmux_index_write32(gmux_data, port, val);

	else

		gmux_pio_write32(gmux_data, port, val);

}



static bool gmux_is_indexed(struct apple_gmux_data *gmux_data)

{

	u16 val;



	outb(0xaa, gmux_data->iostart + 0xcc);

	outb(0x55, gmux_data->iostart + 0xcd);

	outb(0x00, gmux_data->iostart + 0xce);



	val = inb(gmux_data->iostart + 0xcc) |

		(inb(gmux_data->iostart + 0xcd) << 8);



	if (val == 0x55aa)

		return true;



	return false;

}



static int gmux_get_brightness(struct backlight_device *bd)

{

	struct apple_gmux_data *gmux_data = bl_get_data(bd);
@@ -150,21 +294,28 @@ static int __devinit gmux_probe(struct pnp_dev *pnp, 
	}



	/*

	 * On some machines the gmux is in ACPI even thought the machine

	 * doesn't really have a gmux. Check for invalid version information

	 * to detect this.

	 * Invalid version information may indicate either that the gmux

	 * device isn't present or that it's a new one that uses indexed

	 * io

	 */



	ver_major = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR);

	ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR);

	ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE);

	if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {

		if (gmux_is_indexed(gmux_data)) {

			mutex_init(&gmux_data->index_lock);

			gmux_data->indexed = true;

		} else {

			pr_info("gmux device not present\n");

			ret = -ENODEV;

			goto err_release;

		}



		pr_info("Found indexed gmux\n");

	} else {

		pr_info("Found gmux version %d.%d.%d\n", ver_major, ver_minor,

			ver_release);

	}



	memset(&props, 0, sizeof(props));

	props.type = BACKLIGHT_PLATFORM;

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