[net-next-2.6.git] / arch / x86 / kernel / olpc.c

/*
 * 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/setup.h>
#include <asm/olpc.h>
#include <asm/olpc_ofw.h>

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..
	 */
	pr_devel("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;
			}
			pr_devel("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);
			pr_devel("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_OLPC_OPENFIRMWARE
static void __init platform_detect(void)
{
	size_t propsize;
	__be32 rev;
	const void *args[] = { NULL, "board-revision-int", &rev, (void *)4 };
	void *res[] = { &propsize };

	if (olpc_ofw("getprop", args, res) || 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 = olpc_board(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() || cs5535_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);

#ifdef CONFIG_PCI_OLPC
	/* If the VSA exists let it emulate PCI, if not emulate in kernel.
	 * XO-1 only. */
	if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) &&
			!cs5535_has_vsa2())
		x86_init.pci.arch_init = pci_olpc_init;
#endif

	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);
Commit	Line	Data
3ef0e1f8 AS	1	/*
	2	* Support for the OLPC DCON and OLPC EC access
	3	*
	4	* Copyright © 2006 Advanced Micro Devices, Inc.
	5	* Copyright © 2007-2008 Andres Salomon <dilinger@debian.org>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License, or
	10	* (at your option) any later version.
	11	*/
	12
	13	#include <linux/kernel.h>
	14	#include <linux/init.h>
	15	#include <linux/module.h>
	16	#include <linux/delay.h>
	17	#include <linux/spinlock.h>
	18	#include <linux/io.h>
	19	#include <linux/string.h>
d5d0e88c	20
3ef0e1f8	21	#include <asm/geode.h>
d5d0e88c	22	#include <asm/setup.h>
3ef0e1f8	23	#include <asm/olpc.h>
fd699c76	24	#include <asm/olpc_ofw.h>
3ef0e1f8 AS	25
	26	struct olpc_platform_t olpc_platform_info;
	27	EXPORT_SYMBOL_GPL(olpc_platform_info);
	28
	29	static DEFINE_SPINLOCK(ec_lock);
	30
	31	/* what the timeout should be (in ms) */
	32	#define EC_BASE_TIMEOUT 20
	33
	34	/* the timeout that bugs in the EC might force us to actually use */
	35	static int ec_timeout = EC_BASE_TIMEOUT;
	36
	37	static int __init olpc_ec_timeout_set(char *str)
	38	{
	39	if (get_option(&str, &ec_timeout) != 1) {
	40	ec_timeout = EC_BASE_TIMEOUT;
	41	printk(KERN_ERR "olpc-ec: invalid argument to "
	42	"'olpc_ec_timeout=', ignoring!\n");
	43	}
	44	printk(KERN_DEBUG "olpc-ec: using %d ms delay for EC commands.\n",
	45	ec_timeout);
	46	return 1;
	47	}
	48	__setup("olpc_ec_timeout=", olpc_ec_timeout_set);
	49
	50	/*
	51	* These {i,o}bf_status functions return whether the buffers are full or not.
	52	*/
	53
	54	static inline unsigned int ibf_status(unsigned int port)
	55	{
	56	return !!(inb(port) & 0x02);
	57	}
	58
	59	static inline unsigned int obf_status(unsigned int port)
	60	{
	61	return inb(port) & 0x01;
	62	}
	63
	64	#define wait_on_ibf(p, d) __wait_on_ibf(__LINE__, (p), (d))
	65	static int __wait_on_ibf(unsigned int line, unsigned int port, int desired)
	66	{
	67	unsigned int timeo;
	68	int state = ibf_status(port);
	69
	70	for (timeo = ec_timeout; state != desired && timeo; timeo--) {
	71	mdelay(1);
	72	state = ibf_status(port);
	73	}
	74
	75	if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
	76	timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
	77	printk(KERN_WARNING "olpc-ec: %d: waited %u ms for IBF!\n",
	78	line, ec_timeout - timeo);
	79	}
	80
	81	return !(state == desired);
	82	}
	83
	84	#define wait_on_obf(p, d) __wait_on_obf(__LINE__, (p), (d))
	85	static int __wait_on_obf(unsigned int line, unsigned int port, int desired)
	86	{
	87	unsigned int timeo;
	88	int state = obf_status(port);
89
90	for (timeo = ec_timeout; state != desired && timeo; timeo--) {
91	mdelay(1);
92	state = obf_status(port);
93	}
94
95	if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
96	timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
97	printk(KERN_WARNING "olpc-ec: %d: waited %u ms for OBF!\n",
98	line, ec_timeout - timeo);
99	}
100
101	return !(state == desired);
102	}
103
104	/*
105	* This allows the kernel to run Embedded Controller commands. The EC is
106	* documented at <http://wiki.laptop.org/go/Embedded_controller>, and the
107	* available EC commands are here:
108	* <http://wiki.laptop.org/go/Ec_specification>. Unfortunately, while
109	* OpenFirmware's source is available, the EC's is not.
110	*/
111	int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
112	unsigned char *outbuf, size_t outlen)
113	{
114	unsigned long flags;
115	int ret = -EIO;
116	int i;
117
118	spin_lock_irqsave(&ec_lock, flags);
119
120	/* Clear OBF */
121	for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++)
122	inb(0x68);
123	if (i == 10) {
124	printk(KERN_ERR "olpc-ec: timeout while attempting to "
125	"clear OBF flag!\n");
126	goto err;
127	}
128
129	if (wait_on_ibf(0x6c, 0)) {
130	printk(KERN_ERR "olpc-ec: timeout waiting for EC to "
131	"quiesce!\n");
132	goto err;
133	}
134
135	restart:
136	/*
137	* Note that if we time out during any IBF checks, that's a failure;
138	* we have to return. There's no way for the kernel to clear that.
139	*
140	* If we time out during an OBF check, we can restart the command;
141	* reissuing it will clear the OBF flag, and we should be alright.
142	* The OBF flag will sometimes misbehave due to what we believe
143	* is a hardware quirk..
144	*/
25971865	145	pr_devel("olpc-ec: running cmd 0x%x\n", cmd);
3ef0e1f8 AS	146	outb(cmd, 0x6c);
	147
	148	if (wait_on_ibf(0x6c, 0)) {
	149	printk(KERN_ERR "olpc-ec: timeout waiting for EC to read "
	150	"command!\n");
	151	goto err;
	152	}
	153
	154	if (inbuf && inlen) {
	155	/* write data to EC */
	156	for (i = 0; i < inlen; i++) {
	157	if (wait_on_ibf(0x6c, 0)) {
	158	printk(KERN_ERR "olpc-ec: timeout waiting for"
	159	" EC accept data!\n");
	160	goto err;
	161	}
25971865	162	pr_devel("olpc-ec: sending cmd arg 0x%x\n", inbuf[i]);
3ef0e1f8 AS	163	outb(inbuf[i], 0x68);
	164	}
	165	}
	166	if (outbuf && outlen) {
	167	/* read data from EC */
	168	for (i = 0; i < outlen; i++) {
	169	if (wait_on_obf(0x6c, 1)) {
	170	printk(KERN_ERR "olpc-ec: timeout waiting for"
	171	" EC to provide data!\n");
	172	goto restart;
	173	}
	174	outbuf[i] = inb(0x68);
25971865	175	pr_devel("olpc-ec: received 0x%x\n", outbuf[i]);
3ef0e1f8 AS	176	}
	177	}
	178
	179	ret = 0;
	180	err:
	181	spin_unlock_irqrestore(&ec_lock, flags);
	182	return ret;
	183	}
	184	EXPORT_SYMBOL_GPL(olpc_ec_cmd);
	185
fd699c76	186	#ifdef CONFIG_OLPC_OPENFIRMWARE
3ef0e1f8 AS	187	static void __init platform_detect(void)
	188	{
	189	size_t propsize;
e51a1ac2	190	__be32 rev;
54e5bc02	191	const void args[] = { NULL, "board-revision-int", &rev, (void )4 };
fd699c76	192	void *res[] = { &propsize };
3ef0e1f8	193
fd699c76	194	if (olpc_ofw("getprop", args, res) \|\| propsize != 4) {
3ef0e1f8	195	printk(KERN_ERR "ofw: getprop call failed!\n");
e51a1ac2	196	rev = cpu_to_be32(0);
3ef0e1f8 AS	197	}
	198	olpc_platform_info.boardrev = be32_to_cpu(rev);
	199	}
	200	#else
	201	static void __init platform_detect(void)
	202	{
	203	/* stopgap until OFW support is added to the kernel */
e49590b6	204	olpc_platform_info.boardrev = olpc_board(0xc2);
3ef0e1f8 AS	205	}
	206	#endif
	207
	208	static int __init olpc_init(void)
	209	{
	210	unsigned char *romsig;
	211
	212	/* The ioremap check is dangerous; limit what we run it on */
f060f270	213	if (!is_geode() \|\| cs5535_has_vsa2())
3ef0e1f8 AS	214	return 0;
	215
	216	spin_lock_init(&ec_lock);
	217
	218	romsig = ioremap(0xffffffc0, 16);
	219	if (!romsig)
	220	return 0;
	221
	222	if (strncmp(romsig, "CL1 Q", 7))
	223	goto unmap;
	224	if (strncmp(romsig+6, romsig+13, 3)) {
	225	printk(KERN_INFO "OLPC BIOS signature looks invalid. "
	226	"Assuming not OLPC\n");
	227	goto unmap;
	228	}
	229
	230	printk(KERN_INFO "OLPC board with OpenFirmware %.16s\n", romsig);
	231	olpc_platform_info.flags \|= OLPC_F_PRESENT;
	232
	233	/* get the platform revision */
	234	platform_detect();
	235
	236	/* assume B1 and above models always have a DCON */
	237	if (olpc_board_at_least(olpc_board(0xb1)))
	238	olpc_platform_info.flags \|= OLPC_F_DCON;
	239
	240	/* get the EC revision */
	241	olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0,
	242	(unsigned char *) &olpc_platform_info.ecver, 1);
	243
d5d0e88c	244	#ifdef CONFIG_PCI_OLPC
76fb6570 DD	245	/* If the VSA exists let it emulate PCI, if not emulate in kernel.
	246	* XO-1 only. */
	247	if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) &&
	248	!cs5535_has_vsa2())
d5d0e88c TG	249	x86_init.pci.arch_init = pci_olpc_init;
d5d0e88c TG	250	#endif
3ef0e1f8 AS	251
	252	printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n",
	253	((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "",
	254	olpc_platform_info.boardrev >> 4,
	255	olpc_platform_info.ecver);
	256
	257	unmap:
	258	iounmap(romsig);
	259	return 0;
	260	}
	261
	262	postcore_initcall(olpc_init);