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authorGlenn Elliott <gelliott@cs.unc.edu>2012-03-04 19:47:13 -0500
committerGlenn Elliott <gelliott@cs.unc.edu>2012-03-04 19:47:13 -0500
commitc71c03bda1e86c9d5198c5d83f712e695c4f2a1e (patch)
treeecb166cb3e2b7e2adb3b5e292245fefd23381ac8 /arch/x86/platform/olpc/olpc.c
parentea53c912f8a86a8567697115b6a0d8152beee5c8 (diff)
parent6a00f206debf8a5c8899055726ad127dbeeed098 (diff)
Merge branch 'mpi-master' into wip-k-fmlpwip-k-fmlp
Conflicts: litmus/sched_cedf.c
Diffstat (limited to 'arch/x86/platform/olpc/olpc.c')
-rw-r--r--arch/x86/platform/olpc/olpc.c284
1 files changed, 284 insertions, 0 deletions
diff --git a/arch/x86/platform/olpc/olpc.c b/arch/x86/platform/olpc/olpc.c
new file mode 100644
index 000000000000..0060fd59ea00
--- /dev/null
+++ b/arch/x86/platform/olpc/olpc.c
@@ -0,0 +1,284 @@
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>
20#include <linux/platform_device.h>
21#include <linux/of.h>
22
23#include <asm/geode.h>
24#include <asm/setup.h>
25#include <asm/olpc.h>
26#include <asm/olpc_ofw.h>
27
28struct olpc_platform_t olpc_platform_info;
29EXPORT_SYMBOL_GPL(olpc_platform_info);
30
31static DEFINE_SPINLOCK(ec_lock);
32
33/* what the timeout *should* be (in ms) */
34#define EC_BASE_TIMEOUT 20
35
36/* the timeout that bugs in the EC might force us to actually use */
37static int ec_timeout = EC_BASE_TIMEOUT;
38
39static int __init olpc_ec_timeout_set(char *str)
40{
41 if (get_option(&str, &ec_timeout) != 1) {
42 ec_timeout = EC_BASE_TIMEOUT;
43 printk(KERN_ERR "olpc-ec: invalid argument to "
44 "'olpc_ec_timeout=', ignoring!\n");
45 }
46 printk(KERN_DEBUG "olpc-ec: using %d ms delay for EC commands.\n",
47 ec_timeout);
48 return 1;
49}
50__setup("olpc_ec_timeout=", olpc_ec_timeout_set);
51
52/*
53 * These {i,o}bf_status functions return whether the buffers are full or not.
54 */
55
56static inline unsigned int ibf_status(unsigned int port)
57{
58 return !!(inb(port) & 0x02);
59}
60
61static inline unsigned int obf_status(unsigned int port)
62{
63 return inb(port) & 0x01;
64}
65
66#define wait_on_ibf(p, d) __wait_on_ibf(__LINE__, (p), (d))
67static int __wait_on_ibf(unsigned int line, unsigned int port, int desired)
68{
69 unsigned int timeo;
70 int state = ibf_status(port);
71
72 for (timeo = ec_timeout; state != desired && timeo; timeo--) {
73 mdelay(1);
74 state = ibf_status(port);
75 }
76
77 if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
78 timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
79 printk(KERN_WARNING "olpc-ec: %d: waited %u ms for IBF!\n",
80 line, ec_timeout - timeo);
81 }
82
83 return !(state == desired);
84}
85
86#define wait_on_obf(p, d) __wait_on_obf(__LINE__, (p), (d))
87static int __wait_on_obf(unsigned int line, unsigned int port, int desired)
88{
89 unsigned int timeo;
90 int state = obf_status(port);
91
92 for (timeo = ec_timeout; state != desired && timeo; timeo--) {
93 mdelay(1);
94 state = obf_status(port);
95 }
96
97 if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
98 timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
99 printk(KERN_WARNING "olpc-ec: %d: waited %u ms for OBF!\n",
100 line, ec_timeout - timeo);
101 }
102
103 return !(state == desired);
104}
105
106/*
107 * This allows the kernel to run Embedded Controller commands. The EC is
108 * documented at <http://wiki.laptop.org/go/Embedded_controller>, and the
109 * available EC commands are here:
110 * <http://wiki.laptop.org/go/Ec_specification>. Unfortunately, while
111 * OpenFirmware's source is available, the EC's is not.
112 */
113int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
114 unsigned char *outbuf, size_t outlen)
115{
116 unsigned long flags;
117 int ret = -EIO;
118 int i;
119 int restarts = 0;
120
121 spin_lock_irqsave(&ec_lock, flags);
122
123 /* Clear OBF */
124 for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++)
125 inb(0x68);
126 if (i == 10) {
127 printk(KERN_ERR "olpc-ec: timeout while attempting to "
128 "clear OBF flag!\n");
129 goto err;
130 }
131
132 if (wait_on_ibf(0x6c, 0)) {
133 printk(KERN_ERR "olpc-ec: timeout waiting for EC to "
134 "quiesce!\n");
135 goto err;
136 }
137
138restart:
139 /*
140 * Note that if we time out during any IBF checks, that's a failure;
141 * we have to return. There's no way for the kernel to clear that.
142 *
143 * If we time out during an OBF check, we can restart the command;
144 * reissuing it will clear the OBF flag, and we should be alright.
145 * The OBF flag will sometimes misbehave due to what we believe
146 * is a hardware quirk..
147 */
148 pr_devel("olpc-ec: running cmd 0x%x\n", cmd);
149 outb(cmd, 0x6c);
150
151 if (wait_on_ibf(0x6c, 0)) {
152 printk(KERN_ERR "olpc-ec: timeout waiting for EC to read "
153 "command!\n");
154 goto err;
155 }
156
157 if (inbuf && inlen) {
158 /* write data to EC */
159 for (i = 0; i < inlen; i++) {
160 if (wait_on_ibf(0x6c, 0)) {
161 printk(KERN_ERR "olpc-ec: timeout waiting for"
162 " EC accept data!\n");
163 goto err;
164 }
165 pr_devel("olpc-ec: sending cmd arg 0x%x\n", inbuf[i]);
166 outb(inbuf[i], 0x68);
167 }
168 }
169 if (outbuf && outlen) {
170 /* read data from EC */
171 for (i = 0; i < outlen; i++) {
172 if (wait_on_obf(0x6c, 1)) {
173 printk(KERN_ERR "olpc-ec: timeout waiting for"
174 " EC to provide data!\n");
175 if (restarts++ < 10)
176 goto restart;
177 goto err;
178 }
179 outbuf[i] = inb(0x68);
180 pr_devel("olpc-ec: received 0x%x\n", outbuf[i]);
181 }
182 }
183
184 ret = 0;
185err:
186 spin_unlock_irqrestore(&ec_lock, flags);
187 return ret;
188}
189EXPORT_SYMBOL_GPL(olpc_ec_cmd);
190
191static bool __init check_ofw_architecture(struct device_node *root)
192{
193 const char *olpc_arch;
194 int propsize;
195
196 olpc_arch = of_get_property(root, "architecture", &propsize);
197 return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0;
198}
199
200static u32 __init get_board_revision(struct device_node *root)
201{
202 int propsize;
203 const __be32 *rev;
204
205 rev = of_get_property(root, "board-revision-int", &propsize);
206 if (propsize != 4)
207 return 0;
208
209 return be32_to_cpu(*rev);
210}
211
212static bool __init platform_detect(void)
213{
214 struct device_node *root = of_find_node_by_path("/");
215 bool success;
216
217 if (!root)
218 return false;
219
220 success = check_ofw_architecture(root);
221 if (success) {
222 olpc_platform_info.boardrev = get_board_revision(root);
223 olpc_platform_info.flags |= OLPC_F_PRESENT;
224 }
225
226 of_node_put(root);
227 return success;
228}
229
230static int __init add_xo1_platform_devices(void)
231{
232 struct platform_device *pdev;
233
234 pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0);
235 if (IS_ERR(pdev))
236 return PTR_ERR(pdev);
237
238 pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0);
239 if (IS_ERR(pdev))
240 return PTR_ERR(pdev);
241
242 return 0;
243}
244
245static int __init olpc_init(void)
246{
247 int r = 0;
248
249 if (!olpc_ofw_present() || !platform_detect())
250 return 0;
251
252 spin_lock_init(&ec_lock);
253
254 /* assume B1 and above models always have a DCON */
255 if (olpc_board_at_least(olpc_board(0xb1)))
256 olpc_platform_info.flags |= OLPC_F_DCON;
257
258 /* get the EC revision */
259 olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0,
260 (unsigned char *) &olpc_platform_info.ecver, 1);
261
262#ifdef CONFIG_PCI_OLPC
263 /* If the VSA exists let it emulate PCI, if not emulate in kernel.
264 * XO-1 only. */
265 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) &&
266 !cs5535_has_vsa2())
267 x86_init.pci.arch_init = pci_olpc_init;
268#endif
269
270 printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n",
271 ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "",
272 olpc_platform_info.boardrev >> 4,
273 olpc_platform_info.ecver);
274
275 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */
276 r = add_xo1_platform_devices();
277 if (r)
278 return r;
279 }
280
281 return 0;
282}
283
284postcore_initcall(olpc_init);