arch/x86/kernel/olpc.c - maze/linux - Git at Google

 /*
  * Support for the OLPC DCON and OLPC EC access
  *
  * Copyright © 2006  Advanced Micro Devices, Inc.
  * Copyright © 2007-2008  Andres Salomon <dilinger@debian.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  */

 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/string.h>
 #include <asm/geode.h>
 #include <asm/olpc.h>

 #ifdef CONFIG_OPEN_FIRMWARE
 #include <asm/ofw.h>
 #endif

 struct olpc_platform_t olpc_platform_info;
 EXPORT_SYMBOL_GPL(olpc_platform_info);

 static DEFINE_SPINLOCK(ec_lock);

 /* what the timeout *should* be (in ms) */
 #define EC_BASE_TIMEOUT 20

 /* the timeout that bugs in the EC might force us to actually use */
 static int ec_timeout = EC_BASE_TIMEOUT;

 static int __init olpc_ec_timeout_set(char *str)
 {
 	if (get_option(&str, &ec_timeout) != 1) {
 		ec_timeout = EC_BASE_TIMEOUT;
 		printk(KERN_ERR "olpc-ec:  invalid argument to "
 				"'olpc_ec_timeout=', ignoring!\n");
 	}
 	printk(KERN_DEBUG "olpc-ec:  using %d ms delay for EC commands.\n",
 			ec_timeout);
 	return 1;
 }
 __setup("olpc_ec_timeout=", olpc_ec_timeout_set);

 /*
  * These {i,o}bf_status functions return whether the buffers are full or not.
  */

 static inline unsigned int ibf_status(unsigned int port)
 {
 	return !!(inb(port) & 0x02);
 }

 static inline unsigned int obf_status(unsigned int port)
 {
 	return inb(port) & 0x01;
 }

 #define wait_on_ibf(p, d) __wait_on_ibf(__LINE__, (p), (d))
 static int __wait_on_ibf(unsigned int line, unsigned int port, int desired)
 {
 	unsigned int timeo;
 	int state = ibf_status(port);

 	for (timeo = ec_timeout; state != desired && timeo; timeo--) {
 		mdelay(1);
 		state = ibf_status(port);
 	}

 	if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
 			timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
 		printk(KERN_WARNING "olpc-ec:  %d: waited %u ms for IBF!\n",
 				line, ec_timeout - timeo);
 	}

 	return !(state == desired);
 }

 #define wait_on_obf(p, d) __wait_on_obf(__LINE__, (p), (d))
 static int __wait_on_obf(unsigned int line, unsigned int port, int desired)
 {
 	unsigned int timeo;
 	int state = obf_status(port);

 	for (timeo = ec_timeout; state != desired && timeo; timeo--) {
 		mdelay(1);
 		state = obf_status(port);
 	}

 	if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
 			timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
 		printk(KERN_WARNING "olpc-ec:  %d: waited %u ms for OBF!\n",
 				line, ec_timeout - timeo);
 	}

 	return !(state == desired);
 }

 /*
  * This allows the kernel to run Embedded Controller commands.  The EC is
  * documented at <http://wiki.laptop.org/go/Embedded_controller>, and the
  * available EC commands are here:
  * <http://wiki.laptop.org/go/Ec_specification>.  Unfortunately, while
  * OpenFirmware's source is available, the EC's is not.
  */
 int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
 		unsigned char *outbuf,  size_t outlen)
 {
 	unsigned long flags;
 	int ret = -EIO;
 	int i;

 	spin_lock_irqsave(&ec_lock, flags);

 	/* Clear OBF */
 	for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++)
 		inb(0x68);
 	if (i == 10) {
 		printk(KERN_ERR "olpc-ec:  timeout while attempting to "
 				"clear OBF flag!\n");
 		goto err;
 	}

 	if (wait_on_ibf(0x6c, 0)) {
 		printk(KERN_ERR "olpc-ec:  timeout waiting for EC to "
 				"quiesce!\n");
 		goto err;
 	}

 restart:
 	/*
 	 * Note that if we time out during any IBF checks, that's a failure;
 	 * we have to return.  There's no way for the kernel to clear that.
 	 *
 	 * If we time out during an OBF check, we can restart the command;
 	 * reissuing it will clear the OBF flag, and we should be alright.
 	 * The OBF flag will sometimes misbehave due to what we believe
 	 * is a hardware quirk..
 	 */
 	printk(KERN_DEBUG "olpc-ec:  running cmd 0x%x\n", cmd);
 	outb(cmd, 0x6c);

 	if (wait_on_ibf(0x6c, 0)) {
 		printk(KERN_ERR "olpc-ec:  timeout waiting for EC to read "
 				"command!\n");
 		goto err;
 	}

 	if (inbuf && inlen) {
 		/* write data to EC */
 		for (i = 0; i < inlen; i++) {
 			if (wait_on_ibf(0x6c, 0)) {
 				printk(KERN_ERR "olpc-ec:  timeout waiting for"
 						" EC accept data!\n");
 				goto err;
 			}
 			printk(KERN_DEBUG "olpc-ec:  sending cmd arg 0x%x\n",
 					inbuf[i]);
 			outb(inbuf[i], 0x68);
 		}
 	}
 	if (outbuf && outlen) {
 		/* read data from EC */
 		for (i = 0; i < outlen; i++) {
 			if (wait_on_obf(0x6c, 1)) {
 				printk(KERN_ERR "olpc-ec:  timeout waiting for"
 						" EC to provide data!\n");
 				goto restart;
 			}
 			outbuf[i] = inb(0x68);
 			printk(KERN_DEBUG "olpc-ec:  received 0x%x\n",
 					outbuf[i]);
 		}
 	}

 	ret = 0;
 err:
 	spin_unlock_irqrestore(&ec_lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(olpc_ec_cmd);

 #ifdef CONFIG_OPEN_FIRMWARE
 static void __init platform_detect(void)
 {
 	size_t propsize;
 	__be32 rev;

 	if (ofw("getprop", 4, 1, NULL, "board-revision-int", &rev, 4,
 			&propsize) || propsize != 4) {
 		printk(KERN_ERR "ofw: getprop call failed!\n");
 		rev = cpu_to_be32(0);
 	}
 	olpc_platform_info.boardrev = be32_to_cpu(rev);
 }
 #else
 static void __init platform_detect(void)
 {
 	/* stopgap until OFW support is added to the kernel */
 	olpc_platform_info.boardrev = 0xc2;
 }
 #endif

 static int __init olpc_init(void)
 {
 	unsigned char *romsig;

 	/* The ioremap check is dangerous; limit what we run it on */
 	if (!is_geode() || geode_has_vsa2())
 		return 0;

 	spin_lock_init(&ec_lock);

 	romsig = ioremap(0xffffffc0, 16);
 	if (!romsig)
 		return 0;

 	if (strncmp(romsig, "CL1   Q", 7))
 		goto unmap;
 	if (strncmp(romsig+6, romsig+13, 3)) {
 		printk(KERN_INFO "OLPC BIOS signature looks invalid.  "
 				"Assuming not OLPC\n");
 		goto unmap;
 	}

 	printk(KERN_INFO "OLPC board with OpenFirmware %.16s\n", romsig);
 	olpc_platform_info.flags |= OLPC_F_PRESENT;

 	/* get the platform revision */
 	platform_detect();

 	/* assume B1 and above models always have a DCON */
 	if (olpc_board_at_least(olpc_board(0xb1)))
 		olpc_platform_info.flags |= OLPC_F_DCON;

 	/* get the EC revision */
 	olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0,
 			(unsigned char *) &olpc_platform_info.ecver, 1);

 	/* check to see if the VSA exists */
 	if (geode_has_vsa2())
 		olpc_platform_info.flags |= OLPC_F_VSA;

 	printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n",
 			((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "",
 			olpc_platform_info.boardrev >> 4,
 			olpc_platform_info.ecver);

 unmap:
 	iounmap(romsig);
 	return 0;
 }

 postcore_initcall(olpc_init);
	/*
	* Support for the OLPC DCON and OLPC EC access
	*
	* Copyright © 2006 Advanced Micro Devices, Inc.
	* Copyright © 2007-2008 Andres Salomon <dilinger@debian.org>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*/

	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/spinlock.h>
	#include <linux/io.h>
	#include <linux/string.h>
	#include <asm/geode.h>
	#include <asm/olpc.h>

	#ifdef CONFIG_OPEN_FIRMWARE
	#include <asm/ofw.h>
	#endif

	struct olpc_platform_t olpc_platform_info;
	EXPORT_SYMBOL_GPL(olpc_platform_info);

	static DEFINE_SPINLOCK(ec_lock);

	/* what the timeout should be (in ms) */
	#define EC_BASE_TIMEOUT 20

	/* the timeout that bugs in the EC might force us to actually use */
	static int ec_timeout = EC_BASE_TIMEOUT;

	static int __init olpc_ec_timeout_set(char *str)
	{
	if (get_option(&str, &ec_timeout) != 1) {
	ec_timeout = EC_BASE_TIMEOUT;
	printk(KERN_ERR "olpc-ec: invalid argument to "
	"'olpc_ec_timeout=', ignoring!\n");
	}
	printk(KERN_DEBUG "olpc-ec: using %d ms delay for EC commands.\n",
	ec_timeout);
	return 1;
	}
	__setup("olpc_ec_timeout=", olpc_ec_timeout_set);

	/*
	* These {i,o}bf_status functions return whether the buffers are full or not.
	*/

	static inline unsigned int ibf_status(unsigned int port)
	{
	return !!(inb(port) & 0x02);
	}

	static inline unsigned int obf_status(unsigned int port)
	{
	return inb(port) & 0x01;
	}

	#define wait_on_ibf(p, d) __wait_on_ibf(__LINE__, (p), (d))
	static int __wait_on_ibf(unsigned int line, unsigned int port, int desired)
	{
	unsigned int timeo;
	int state = ibf_status(port);

	for (timeo = ec_timeout; state != desired && timeo; timeo--) {
	mdelay(1);
	state = ibf_status(port);
	}

	if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
	timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
	printk(KERN_WARNING "olpc-ec: %d: waited %u ms for IBF!\n",
	line, ec_timeout - timeo);
	}

	return !(state == desired);
	}

	#define wait_on_obf(p, d) __wait_on_obf(__LINE__, (p), (d))
	static int __wait_on_obf(unsigned int line, unsigned int port, int desired)
	{
	unsigned int timeo;
	int state = obf_status(port);

	for (timeo = ec_timeout; state != desired && timeo; timeo--) {
	mdelay(1);
	state = obf_status(port);
	}

	if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
	timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
	printk(KERN_WARNING "olpc-ec: %d: waited %u ms for OBF!\n",
	line, ec_timeout - timeo);
	}

	return !(state == desired);
	}

	/*
	* This allows the kernel to run Embedded Controller commands. The EC is
	* documented at <http://wiki.laptop.org/go/Embedded_controller>, and the
	* available EC commands are here:
	* <http://wiki.laptop.org/go/Ec_specification>. Unfortunately, while
	* OpenFirmware's source is available, the EC's is not.
	*/
	int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
	unsigned char *outbuf, size_t outlen)
	{
	unsigned long flags;
	int ret = -EIO;
	int i;

	spin_lock_irqsave(&ec_lock, flags);

	/* Clear OBF */
	for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++)
	inb(0x68);
	if (i == 10) {
	printk(KERN_ERR "olpc-ec: timeout while attempting to "
	"clear OBF flag!\n");
	goto err;
	}

	if (wait_on_ibf(0x6c, 0)) {
	printk(KERN_ERR "olpc-ec: timeout waiting for EC to "
	"quiesce!\n");
	goto err;
	}

	restart:
	/*
	* Note that if we time out during any IBF checks, that's a failure;
	* we have to return. There's no way for the kernel to clear that.
	*
	* If we time out during an OBF check, we can restart the command;
	* reissuing it will clear the OBF flag, and we should be alright.
	* The OBF flag will sometimes misbehave due to what we believe
	* is a hardware quirk..
	*/
	printk(KERN_DEBUG "olpc-ec: running cmd 0x%x\n", cmd);
	outb(cmd, 0x6c);

	if (wait_on_ibf(0x6c, 0)) {
	printk(KERN_ERR "olpc-ec: timeout waiting for EC to read "
	"command!\n");
	goto err;
	}

	if (inbuf && inlen) {
	/* write data to EC */
	for (i = 0; i < inlen; i++) {
	if (wait_on_ibf(0x6c, 0)) {
	printk(KERN_ERR "olpc-ec: timeout waiting for"
	" EC accept data!\n");
	goto err;
	}
	printk(KERN_DEBUG "olpc-ec: sending cmd arg 0x%x\n",
	inbuf[i]);
	outb(inbuf[i], 0x68);
	}
	}
	if (outbuf && outlen) {
	/* read data from EC */
	for (i = 0; i < outlen; i++) {
	if (wait_on_obf(0x6c, 1)) {
	printk(KERN_ERR "olpc-ec: timeout waiting for"
	" EC to provide data!\n");
	goto restart;
	}
	outbuf[i] = inb(0x68);
	printk(KERN_DEBUG "olpc-ec: received 0x%x\n",
	outbuf[i]);
	}
	}

	ret = 0;
	err:
	spin_unlock_irqrestore(&ec_lock, flags);
	return ret;
	}
	EXPORT_SYMBOL_GPL(olpc_ec_cmd);

	#ifdef CONFIG_OPEN_FIRMWARE
	static void __init platform_detect(void)
	{
	size_t propsize;
	__be32 rev;

	if (ofw("getprop", 4, 1, NULL, "board-revision-int", &rev, 4,
	&propsize) \|\| propsize != 4) {
	printk(KERN_ERR "ofw: getprop call failed!\n");
	rev = cpu_to_be32(0);
	}
	olpc_platform_info.boardrev = be32_to_cpu(rev);
	}
	#else
	static void __init platform_detect(void)
	{
	/* stopgap until OFW support is added to the kernel */
	olpc_platform_info.boardrev = 0xc2;
	}
	#endif

	static int __init olpc_init(void)
	{
	unsigned char *romsig;

	/* The ioremap check is dangerous; limit what we run it on */
	if (!is_geode() \|\| geode_has_vsa2())
	return 0;

	spin_lock_init(&ec_lock);

	romsig = ioremap(0xffffffc0, 16);
	if (!romsig)
	return 0;

	if (strncmp(romsig, "CL1 Q", 7))
	goto unmap;
	if (strncmp(romsig+6, romsig+13, 3)) {
	printk(KERN_INFO "OLPC BIOS signature looks invalid. "
	"Assuming not OLPC\n");
	goto unmap;
	}

	printk(KERN_INFO "OLPC board with OpenFirmware %.16s\n", romsig);
	olpc_platform_info.flags \|= OLPC_F_PRESENT;

	/* get the platform revision */
	platform_detect();

	/* assume B1 and above models always have a DCON */
	if (olpc_board_at_least(olpc_board(0xb1)))
	olpc_platform_info.flags \|= OLPC_F_DCON;

	/* get the EC revision */
	olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0,
	(unsigned char *) &olpc_platform_info.ecver, 1);

	/* check to see if the VSA exists */
	if (geode_has_vsa2())
	olpc_platform_info.flags \|= OLPC_F_VSA;

	printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n",
	((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "",
	olpc_platform_info.boardrev >> 4,
	olpc_platform_info.ecver);

	unmap:
	iounmap(romsig);
	return 0;
	}

	postcore_initcall(olpc_init);