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 #include <linux/syscore_ops.h>
23
24 #include <asm/geode.h>
25 #include <asm/setup.h>
26 #include <asm/olpc.h>
27 #include <asm/olpc_ofw.h>
28
29 struct olpc_platform_t olpc_platform_info;
30 EXPORT_SYMBOL_GPL(olpc_platform_info);
31
32 static DEFINE_SPINLOCK(ec_lock);
33
34 /* EC event mask to be applied during suspend (defining wakeup sources). */
35 static u16 ec_wakeup_mask;
36
37 /* what the timeout *should* be (in ms) */
38 #define EC_BASE_TIMEOUT 20
39
40 /* the timeout that bugs in the EC might force us to actually use */
41 static int ec_timeout = EC_BASE_TIMEOUT;
42
olpc_ec_timeout_set(char * str)43 static int __init olpc_ec_timeout_set(char *str)
44 {
45 if (get_option(&str, &ec_timeout) != 1) {
46 ec_timeout = EC_BASE_TIMEOUT;
47 printk(KERN_ERR "olpc-ec: invalid argument to "
48 "'olpc_ec_timeout=', ignoring!\n");
49 }
50 printk(KERN_DEBUG "olpc-ec: using %d ms delay for EC commands.\n",
51 ec_timeout);
52 return 1;
53 }
54 __setup("olpc_ec_timeout=", olpc_ec_timeout_set);
55
56 /*
57 * These {i,o}bf_status functions return whether the buffers are full or not.
58 */
59
ibf_status(unsigned int port)60 static inline unsigned int ibf_status(unsigned int port)
61 {
62 return !!(inb(port) & 0x02);
63 }
64
obf_status(unsigned int port)65 static inline unsigned int obf_status(unsigned int port)
66 {
67 return inb(port) & 0x01;
68 }
69
70 #define wait_on_ibf(p, d) __wait_on_ibf(__LINE__, (p), (d))
__wait_on_ibf(unsigned int line,unsigned int port,int desired)71 static int __wait_on_ibf(unsigned int line, unsigned int port, int desired)
72 {
73 unsigned int timeo;
74 int state = ibf_status(port);
75
76 for (timeo = ec_timeout; state != desired && timeo; timeo--) {
77 mdelay(1);
78 state = ibf_status(port);
79 }
80
81 if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
82 timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
83 printk(KERN_WARNING "olpc-ec: %d: waited %u ms for IBF!\n",
84 line, ec_timeout - timeo);
85 }
86
87 return !(state == desired);
88 }
89
90 #define wait_on_obf(p, d) __wait_on_obf(__LINE__, (p), (d))
__wait_on_obf(unsigned int line,unsigned int port,int desired)91 static int __wait_on_obf(unsigned int line, unsigned int port, int desired)
92 {
93 unsigned int timeo;
94 int state = obf_status(port);
95
96 for (timeo = ec_timeout; state != desired && timeo; timeo--) {
97 mdelay(1);
98 state = obf_status(port);
99 }
100
101 if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
102 timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
103 printk(KERN_WARNING "olpc-ec: %d: waited %u ms for OBF!\n",
104 line, ec_timeout - timeo);
105 }
106
107 return !(state == desired);
108 }
109
110 /*
111 * This allows the kernel to run Embedded Controller commands. The EC is
112 * documented at <http://wiki.laptop.org/go/Embedded_controller>, and the
113 * available EC commands are here:
114 * <http://wiki.laptop.org/go/Ec_specification>. Unfortunately, while
115 * OpenFirmware's source is available, the EC's is not.
116 */
olpc_ec_cmd(unsigned char cmd,unsigned char * inbuf,size_t inlen,unsigned char * outbuf,size_t outlen)117 int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
118 unsigned char *outbuf, size_t outlen)
119 {
120 unsigned long flags;
121 int ret = -EIO;
122 int i;
123 int restarts = 0;
124
125 spin_lock_irqsave(&ec_lock, flags);
126
127 /* Clear OBF */
128 for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++)
129 inb(0x68);
130 if (i == 10) {
131 printk(KERN_ERR "olpc-ec: timeout while attempting to "
132 "clear OBF flag!\n");
133 goto err;
134 }
135
136 if (wait_on_ibf(0x6c, 0)) {
137 printk(KERN_ERR "olpc-ec: timeout waiting for EC to "
138 "quiesce!\n");
139 goto err;
140 }
141
142 restart:
143 /*
144 * Note that if we time out during any IBF checks, that's a failure;
145 * we have to return. There's no way for the kernel to clear that.
146 *
147 * If we time out during an OBF check, we can restart the command;
148 * reissuing it will clear the OBF flag, and we should be alright.
149 * The OBF flag will sometimes misbehave due to what we believe
150 * is a hardware quirk..
151 */
152 pr_devel("olpc-ec: running cmd 0x%x\n", cmd);
153 outb(cmd, 0x6c);
154
155 if (wait_on_ibf(0x6c, 0)) {
156 printk(KERN_ERR "olpc-ec: timeout waiting for EC to read "
157 "command!\n");
158 goto err;
159 }
160
161 if (inbuf && inlen) {
162 /* write data to EC */
163 for (i = 0; i < inlen; i++) {
164 pr_devel("olpc-ec: sending cmd arg 0x%x\n", inbuf[i]);
165 outb(inbuf[i], 0x68);
166 if (wait_on_ibf(0x6c, 0)) {
167 printk(KERN_ERR "olpc-ec: timeout waiting for"
168 " EC accept data!\n");
169 goto err;
170 }
171 }
172 }
173 if (outbuf && outlen) {
174 /* read data from EC */
175 for (i = 0; i < outlen; i++) {
176 if (wait_on_obf(0x6c, 1)) {
177 printk(KERN_ERR "olpc-ec: timeout waiting for"
178 " EC to provide data!\n");
179 if (restarts++ < 10)
180 goto restart;
181 goto err;
182 }
183 outbuf[i] = inb(0x68);
184 pr_devel("olpc-ec: received 0x%x\n", outbuf[i]);
185 }
186 }
187
188 ret = 0;
189 err:
190 spin_unlock_irqrestore(&ec_lock, flags);
191 return ret;
192 }
193 EXPORT_SYMBOL_GPL(olpc_ec_cmd);
194
olpc_ec_wakeup_set(u16 value)195 void olpc_ec_wakeup_set(u16 value)
196 {
197 ec_wakeup_mask |= value;
198 }
199 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_set);
200
olpc_ec_wakeup_clear(u16 value)201 void olpc_ec_wakeup_clear(u16 value)
202 {
203 ec_wakeup_mask &= ~value;
204 }
205 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_clear);
206
207 /*
208 * Returns true if the compile and runtime configurations allow for EC events
209 * to wake the system.
210 */
olpc_ec_wakeup_available(void)211 bool olpc_ec_wakeup_available(void)
212 {
213 if (!machine_is_olpc())
214 return false;
215
216 /*
217 * XO-1 EC wakeups are available when olpc-xo1-sci driver is
218 * compiled in
219 */
220 #ifdef CONFIG_OLPC_XO1_SCI
221 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) /* XO-1 */
222 return true;
223 #endif
224
225 /*
226 * XO-1.5 EC wakeups are available when olpc-xo15-sci driver is
227 * compiled in
228 */
229 #ifdef CONFIG_OLPC_XO15_SCI
230 if (olpc_platform_info.boardrev >= olpc_board_pre(0xd0)) /* XO-1.5 */
231 return true;
232 #endif
233
234 return false;
235 }
236 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_available);
237
olpc_ec_mask_write(u16 bits)238 int olpc_ec_mask_write(u16 bits)
239 {
240 if (olpc_platform_info.flags & OLPC_F_EC_WIDE_SCI) {
241 __be16 ec_word = cpu_to_be16(bits);
242 return olpc_ec_cmd(EC_WRITE_EXT_SCI_MASK, (void *) &ec_word, 2,
243 NULL, 0);
244 } else {
245 unsigned char ec_byte = bits & 0xff;
246 return olpc_ec_cmd(EC_WRITE_SCI_MASK, &ec_byte, 1, NULL, 0);
247 }
248 }
249 EXPORT_SYMBOL_GPL(olpc_ec_mask_write);
250
olpc_ec_sci_query(u16 * sci_value)251 int olpc_ec_sci_query(u16 *sci_value)
252 {
253 int ret;
254
255 if (olpc_platform_info.flags & OLPC_F_EC_WIDE_SCI) {
256 __be16 ec_word;
257 ret = olpc_ec_cmd(EC_EXT_SCI_QUERY,
258 NULL, 0, (void *) &ec_word, 2);
259 if (ret == 0)
260 *sci_value = be16_to_cpu(ec_word);
261 } else {
262 unsigned char ec_byte;
263 ret = olpc_ec_cmd(EC_SCI_QUERY, NULL, 0, &ec_byte, 1);
264 if (ret == 0)
265 *sci_value = ec_byte;
266 }
267
268 return ret;
269 }
270 EXPORT_SYMBOL_GPL(olpc_ec_sci_query);
271
olpc_ec_suspend(void)272 static int olpc_ec_suspend(void)
273 {
274 return olpc_ec_mask_write(ec_wakeup_mask);
275 }
276
check_ofw_architecture(struct device_node * root)277 static bool __init check_ofw_architecture(struct device_node *root)
278 {
279 const char *olpc_arch;
280 int propsize;
281
282 olpc_arch = of_get_property(root, "architecture", &propsize);
283 return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0;
284 }
285
get_board_revision(struct device_node * root)286 static u32 __init get_board_revision(struct device_node *root)
287 {
288 int propsize;
289 const __be32 *rev;
290
291 rev = of_get_property(root, "board-revision-int", &propsize);
292 if (propsize != 4)
293 return 0;
294
295 return be32_to_cpu(*rev);
296 }
297
platform_detect(void)298 static bool __init platform_detect(void)
299 {
300 struct device_node *root = of_find_node_by_path("/");
301 bool success;
302
303 if (!root)
304 return false;
305
306 success = check_ofw_architecture(root);
307 if (success) {
308 olpc_platform_info.boardrev = get_board_revision(root);
309 olpc_platform_info.flags |= OLPC_F_PRESENT;
310 }
311
312 of_node_put(root);
313 return success;
314 }
315
add_xo1_platform_devices(void)316 static int __init add_xo1_platform_devices(void)
317 {
318 struct platform_device *pdev;
319
320 pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0);
321 if (IS_ERR(pdev))
322 return PTR_ERR(pdev);
323
324 pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0);
325 if (IS_ERR(pdev))
326 return PTR_ERR(pdev);
327
328 return 0;
329 }
330
331 static struct syscore_ops olpc_syscore_ops = {
332 .suspend = olpc_ec_suspend,
333 };
334
olpc_init(void)335 static int __init olpc_init(void)
336 {
337 int r = 0;
338
339 if (!olpc_ofw_present() || !platform_detect())
340 return 0;
341
342 spin_lock_init(&ec_lock);
343
344 /* assume B1 and above models always have a DCON */
345 if (olpc_board_at_least(olpc_board(0xb1)))
346 olpc_platform_info.flags |= OLPC_F_DCON;
347
348 /* get the EC revision */
349 olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0,
350 (unsigned char *) &olpc_platform_info.ecver, 1);
351
352 #ifdef CONFIG_PCI_OLPC
353 /* If the VSA exists let it emulate PCI, if not emulate in kernel.
354 * XO-1 only. */
355 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) &&
356 !cs5535_has_vsa2())
357 x86_init.pci.arch_init = pci_olpc_init;
358 #endif
359 /* EC version 0x5f adds support for wide SCI mask */
360 if (olpc_platform_info.ecver >= 0x5f)
361 olpc_platform_info.flags |= OLPC_F_EC_WIDE_SCI;
362
363 printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n",
364 ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "",
365 olpc_platform_info.boardrev >> 4,
366 olpc_platform_info.ecver);
367
368 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */
369 r = add_xo1_platform_devices();
370 if (r)
371 return r;
372 }
373
374 register_syscore_ops(&olpc_syscore_ops);
375
376 return 0;
377 }
378
379 postcore_initcall(olpc_init);
380