2 * Support for the OLPC DCON and OLPC EC access
4 * Copyright © 2006 Advanced Micro Devices, Inc.
5 * Copyright © 2007-2008 Andres Salomon <dilinger@debian.org>
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.
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>
19 #include <linux/string.h>
20 #include <linux/platform_device.h>
22 #include <asm/geode.h>
23 #include <asm/setup.h>
25 #include <asm/olpc_ofw.h>
27 struct olpc_platform_t olpc_platform_info;
28 EXPORT_SYMBOL_GPL(olpc_platform_info);
30 static DEFINE_SPINLOCK(ec_lock);
32 /* what the timeout *should* be (in ms) */
33 #define EC_BASE_TIMEOUT 20
35 /* the timeout that bugs in the EC might force us to actually use */
36 static int ec_timeout = EC_BASE_TIMEOUT;
38 static int __init olpc_ec_timeout_set(char *str)
40 if (get_option(&str, &ec_timeout) != 1) {
41 ec_timeout = EC_BASE_TIMEOUT;
42 printk(KERN_ERR "olpc-ec: invalid argument to "
43 "'olpc_ec_timeout=', ignoring!\n");
45 printk(KERN_DEBUG "olpc-ec: using %d ms delay for EC commands.\n",
49 __setup("olpc_ec_timeout=", olpc_ec_timeout_set);
52 * These {i,o}bf_status functions return whether the buffers are full or not.
55 static inline unsigned int ibf_status(unsigned int port)
57 return !!(inb(port) & 0x02);
60 static inline unsigned int obf_status(unsigned int port)
62 return inb(port) & 0x01;
65 #define wait_on_ibf(p, d) __wait_on_ibf(__LINE__, (p), (d))
66 static int __wait_on_ibf(unsigned int line, unsigned int port, int desired)
69 int state = ibf_status(port);
71 for (timeo = ec_timeout; state != desired && timeo; timeo--) {
73 state = ibf_status(port);
76 if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
77 timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
78 printk(KERN_WARNING "olpc-ec: %d: waited %u ms for IBF!\n",
79 line, ec_timeout - timeo);
82 return !(state == desired);
85 #define wait_on_obf(p, d) __wait_on_obf(__LINE__, (p), (d))
86 static int __wait_on_obf(unsigned int line, unsigned int port, int desired)
89 int state = obf_status(port);
91 for (timeo = ec_timeout; state != desired && timeo; timeo--) {
93 state = obf_status(port);
96 if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
97 timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
98 printk(KERN_WARNING "olpc-ec: %d: waited %u ms for OBF!\n",
99 line, ec_timeout - timeo);
102 return !(state == desired);
106 * This allows the kernel to run Embedded Controller commands. The EC is
107 * documented at <http://wiki.laptop.org/go/Embedded_controller>, and the
108 * available EC commands are here:
109 * <http://wiki.laptop.org/go/Ec_specification>. Unfortunately, while
110 * OpenFirmware's source is available, the EC's is not.
112 int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
113 unsigned char *outbuf, size_t outlen)
120 spin_lock_irqsave(&ec_lock, flags);
123 for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++)
126 printk(KERN_ERR "olpc-ec: timeout while attempting to "
127 "clear OBF flag!\n");
131 if (wait_on_ibf(0x6c, 0)) {
132 printk(KERN_ERR "olpc-ec: timeout waiting for EC to "
139 * Note that if we time out during any IBF checks, that's a failure;
140 * we have to return. There's no way for the kernel to clear that.
142 * If we time out during an OBF check, we can restart the command;
143 * reissuing it will clear the OBF flag, and we should be alright.
144 * The OBF flag will sometimes misbehave due to what we believe
145 * is a hardware quirk..
147 pr_devel("olpc-ec: running cmd 0x%x\n", cmd);
150 if (wait_on_ibf(0x6c, 0)) {
151 printk(KERN_ERR "olpc-ec: timeout waiting for EC to read "
156 if (inbuf && inlen) {
157 /* write data to EC */
158 for (i = 0; i < inlen; i++) {
159 if (wait_on_ibf(0x6c, 0)) {
160 printk(KERN_ERR "olpc-ec: timeout waiting for"
161 " EC accept data!\n");
164 pr_devel("olpc-ec: sending cmd arg 0x%x\n", inbuf[i]);
165 outb(inbuf[i], 0x68);
168 if (outbuf && outlen) {
169 /* read data from EC */
170 for (i = 0; i < outlen; i++) {
171 if (wait_on_obf(0x6c, 1)) {
172 printk(KERN_ERR "olpc-ec: timeout waiting for"
173 " EC to provide data!\n");
178 outbuf[i] = inb(0x68);
179 pr_devel("olpc-ec: received 0x%x\n", outbuf[i]);
185 spin_unlock_irqrestore(&ec_lock, flags);
188 EXPORT_SYMBOL_GPL(olpc_ec_cmd);
190 static bool __init check_ofw_architecture(void)
194 const void *args[] = { NULL, "architecture", olpc_arch, (void *)5 };
195 void *res[] = { &propsize };
197 if (olpc_ofw("getprop", args, res)) {
198 printk(KERN_ERR "ofw: getprop call failed!\n");
201 return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0;
204 static u32 __init get_board_revision(void)
208 const void *args[] = { NULL, "board-revision-int", &rev, (void *)4 };
209 void *res[] = { &propsize };
211 if (olpc_ofw("getprop", args, res) || propsize != 4) {
212 printk(KERN_ERR "ofw: getprop call failed!\n");
213 return cpu_to_be32(0);
215 return be32_to_cpu(rev);
218 static bool __init platform_detect(void)
220 if (!check_ofw_architecture())
222 olpc_platform_info.flags |= OLPC_F_PRESENT;
223 olpc_platform_info.boardrev = get_board_revision();
227 static int __init add_xo1_platform_devices(void)
229 struct platform_device *pdev;
231 pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0);
233 return PTR_ERR(pdev);
235 pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0);
237 return PTR_ERR(pdev);
242 static int __init olpc_init(void)
246 if (!olpc_ofw_present() || !platform_detect())
249 spin_lock_init(&ec_lock);
251 /* assume B1 and above models always have a DCON */
252 if (olpc_board_at_least(olpc_board(0xb1)))
253 olpc_platform_info.flags |= OLPC_F_DCON;
255 /* get the EC revision */
256 olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0,
257 (unsigned char *) &olpc_platform_info.ecver, 1);
259 #ifdef CONFIG_PCI_OLPC
260 /* If the VSA exists let it emulate PCI, if not emulate in kernel.
262 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) &&
264 x86_init.pci.arch_init = pci_olpc_init;
267 printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n",
268 ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "",
269 olpc_platform_info.boardrev >> 4,
270 olpc_platform_info.ecver);
272 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */
273 r = add_xo1_platform_devices();
281 postcore_initcall(olpc_init);