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/io.h>
18 #include <linux/string.h>
19 #include <linux/platform_device.h>
20 #include <linux/of.h>
21 #include <linux/syscore_ops.h>
22 #include <linux/mutex.h>
23 #include <linux/olpc-ec.h>
24
25 #include <asm/geode.h>
26 #include <asm/setup.h>
27 #include <asm/olpc.h>
28 #include <asm/olpc_ofw.h>
29
30 struct olpc_platform_t olpc_platform_info;
31 EXPORT_SYMBOL_GPL(olpc_platform_info);
32
33 /* EC event mask to be applied during suspend (defining wakeup sources). */
34 static u16 ec_wakeup_mask;
35
36 /* what the timeout *should* be (in ms) */
37 #define EC_BASE_TIMEOUT 20
38
39 /* the timeout that bugs in the EC might force us to actually use */
40 static int ec_timeout = EC_BASE_TIMEOUT;
41
olpc_ec_timeout_set(char * str)42 static int __init olpc_ec_timeout_set(char *str)
43 {
44 if (get_option(&str, &ec_timeout) != 1) {
45 ec_timeout = EC_BASE_TIMEOUT;
46 printk(KERN_ERR "olpc-ec: invalid argument to "
47 "'olpc_ec_timeout=', ignoring!\n");
48 }
49 printk(KERN_DEBUG "olpc-ec: using %d ms delay for EC commands.\n",
50 ec_timeout);
51 return 1;
52 }
53 __setup("olpc_ec_timeout=", olpc_ec_timeout_set);
54
55 /*
56 * These {i,o}bf_status functions return whether the buffers are full or not.
57 */
58
ibf_status(unsigned int port)59 static inline unsigned int ibf_status(unsigned int port)
60 {
61 return !!(inb(port) & 0x02);
62 }
63
obf_status(unsigned int port)64 static inline unsigned int obf_status(unsigned int port)
65 {
66 return inb(port) & 0x01;
67 }
68
69 #define wait_on_ibf(p, d) __wait_on_ibf(__LINE__, (p), (d))
__wait_on_ibf(unsigned int line,unsigned int port,int desired)70 static int __wait_on_ibf(unsigned int line, unsigned int port, int desired)
71 {
72 unsigned int timeo;
73 int state = ibf_status(port);
74
75 for (timeo = ec_timeout; state != desired && timeo; timeo--) {
76 mdelay(1);
77 state = ibf_status(port);
78 }
79
80 if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
81 timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
82 printk(KERN_WARNING "olpc-ec: %d: waited %u ms for IBF!\n",
83 line, ec_timeout - timeo);
84 }
85
86 return !(state == desired);
87 }
88
89 #define wait_on_obf(p, d) __wait_on_obf(__LINE__, (p), (d))
__wait_on_obf(unsigned int line,unsigned int port,int desired)90 static int __wait_on_obf(unsigned int line, unsigned int port, int desired)
91 {
92 unsigned int timeo;
93 int state = obf_status(port);
94
95 for (timeo = ec_timeout; state != desired && timeo; timeo--) {
96 mdelay(1);
97 state = obf_status(port);
98 }
99
100 if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
101 timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
102 printk(KERN_WARNING "olpc-ec: %d: waited %u ms for OBF!\n",
103 line, ec_timeout - timeo);
104 }
105
106 return !(state == desired);
107 }
108
109 /*
110 * This allows the kernel to run Embedded Controller commands. The EC is
111 * documented at <http://wiki.laptop.org/go/Embedded_controller>, and the
112 * available EC commands are here:
113 * <http://wiki.laptop.org/go/Ec_specification>. Unfortunately, while
114 * OpenFirmware's source is available, the EC's is not.
115 */
olpc_xo1_ec_cmd(u8 cmd,u8 * inbuf,size_t inlen,u8 * outbuf,size_t outlen,void * arg)116 static int olpc_xo1_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf,
117 size_t outlen, void *arg)
118 {
119 int ret = -EIO;
120 int i;
121 int restarts = 0;
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
138 restart:
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 pr_devel("olpc-ec: sending cmd arg 0x%x\n", inbuf[i]);
161 outb(inbuf[i], 0x68);
162 if (wait_on_ibf(0x6c, 0)) {
163 printk(KERN_ERR "olpc-ec: timeout waiting for"
164 " EC accept data!\n");
165 goto err;
166 }
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;
185 err:
186 return ret;
187 }
188
olpc_ec_wakeup_set(u16 value)189 void olpc_ec_wakeup_set(u16 value)
190 {
191 ec_wakeup_mask |= value;
192 }
193 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_set);
194
olpc_ec_wakeup_clear(u16 value)195 void olpc_ec_wakeup_clear(u16 value)
196 {
197 ec_wakeup_mask &= ~value;
198 }
199 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_clear);
200
201 /*
202 * Returns true if the compile and runtime configurations allow for EC events
203 * to wake the system.
204 */
olpc_ec_wakeup_available(void)205 bool olpc_ec_wakeup_available(void)
206 {
207 if (!machine_is_olpc())
208 return false;
209
210 /*
211 * XO-1 EC wakeups are available when olpc-xo1-sci driver is
212 * compiled in
213 */
214 #ifdef CONFIG_OLPC_XO1_SCI
215 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) /* XO-1 */
216 return true;
217 #endif
218
219 /*
220 * XO-1.5 EC wakeups are available when olpc-xo15-sci driver is
221 * compiled in
222 */
223 #ifdef CONFIG_OLPC_XO15_SCI
224 if (olpc_platform_info.boardrev >= olpc_board_pre(0xd0)) /* XO-1.5 */
225 return true;
226 #endif
227
228 return false;
229 }
230 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_available);
231
olpc_ec_mask_write(u16 bits)232 int olpc_ec_mask_write(u16 bits)
233 {
234 if (olpc_platform_info.flags & OLPC_F_EC_WIDE_SCI) {
235 __be16 ec_word = cpu_to_be16(bits);
236 return olpc_ec_cmd(EC_WRITE_EXT_SCI_MASK, (void *) &ec_word, 2,
237 NULL, 0);
238 } else {
239 unsigned char ec_byte = bits & 0xff;
240 return olpc_ec_cmd(EC_WRITE_SCI_MASK, &ec_byte, 1, NULL, 0);
241 }
242 }
243 EXPORT_SYMBOL_GPL(olpc_ec_mask_write);
244
olpc_ec_sci_query(u16 * sci_value)245 int olpc_ec_sci_query(u16 *sci_value)
246 {
247 int ret;
248
249 if (olpc_platform_info.flags & OLPC_F_EC_WIDE_SCI) {
250 __be16 ec_word;
251 ret = olpc_ec_cmd(EC_EXT_SCI_QUERY,
252 NULL, 0, (void *) &ec_word, 2);
253 if (ret == 0)
254 *sci_value = be16_to_cpu(ec_word);
255 } else {
256 unsigned char ec_byte;
257 ret = olpc_ec_cmd(EC_SCI_QUERY, NULL, 0, &ec_byte, 1);
258 if (ret == 0)
259 *sci_value = ec_byte;
260 }
261
262 return ret;
263 }
264 EXPORT_SYMBOL_GPL(olpc_ec_sci_query);
265
check_ofw_architecture(struct device_node * root)266 static bool __init check_ofw_architecture(struct device_node *root)
267 {
268 const char *olpc_arch;
269 int propsize;
270
271 olpc_arch = of_get_property(root, "architecture", &propsize);
272 return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0;
273 }
274
get_board_revision(struct device_node * root)275 static u32 __init get_board_revision(struct device_node *root)
276 {
277 int propsize;
278 const __be32 *rev;
279
280 rev = of_get_property(root, "board-revision-int", &propsize);
281 if (propsize != 4)
282 return 0;
283
284 return be32_to_cpu(*rev);
285 }
286
platform_detect(void)287 static bool __init platform_detect(void)
288 {
289 struct device_node *root = of_find_node_by_path("/");
290 bool success;
291
292 if (!root)
293 return false;
294
295 success = check_ofw_architecture(root);
296 if (success) {
297 olpc_platform_info.boardrev = get_board_revision(root);
298 olpc_platform_info.flags |= OLPC_F_PRESENT;
299 }
300
301 of_node_put(root);
302 return success;
303 }
304
add_xo1_platform_devices(void)305 static int __init add_xo1_platform_devices(void)
306 {
307 struct platform_device *pdev;
308
309 pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0);
310 if (IS_ERR(pdev))
311 return PTR_ERR(pdev);
312
313 pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0);
314 if (IS_ERR(pdev))
315 return PTR_ERR(pdev);
316
317 return 0;
318 }
319
olpc_xo1_ec_probe(struct platform_device * pdev)320 static int olpc_xo1_ec_probe(struct platform_device *pdev)
321 {
322 /* get the EC revision */
323 olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0,
324 (unsigned char *) &olpc_platform_info.ecver, 1);
325
326 /* EC version 0x5f adds support for wide SCI mask */
327 if (olpc_platform_info.ecver >= 0x5f)
328 olpc_platform_info.flags |= OLPC_F_EC_WIDE_SCI;
329
330 pr_info("OLPC board revision %s%X (EC=%x)\n",
331 ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "",
332 olpc_platform_info.boardrev >> 4,
333 olpc_platform_info.ecver);
334
335 return 0;
336 }
olpc_xo1_ec_suspend(struct platform_device * pdev)337 static int olpc_xo1_ec_suspend(struct platform_device *pdev)
338 {
339 olpc_ec_mask_write(ec_wakeup_mask);
340
341 /*
342 * Squelch SCIs while suspended. This is a fix for
343 * <http://dev.laptop.org/ticket/1835>.
344 */
345 return olpc_ec_cmd(EC_SET_SCI_INHIBIT, NULL, 0, NULL, 0);
346 }
347
olpc_xo1_ec_resume(struct platform_device * pdev)348 static int olpc_xo1_ec_resume(struct platform_device *pdev)
349 {
350 /* Tell the EC to stop inhibiting SCIs */
351 olpc_ec_cmd(EC_SET_SCI_INHIBIT_RELEASE, NULL, 0, NULL, 0);
352
353 /*
354 * Tell the wireless module to restart USB communication.
355 * Must be done twice.
356 */
357 olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0);
358 olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0);
359
360 return 0;
361 }
362
363 static struct olpc_ec_driver ec_xo1_driver = {
364 .probe = olpc_xo1_ec_probe,
365 .suspend = olpc_xo1_ec_suspend,
366 .resume = olpc_xo1_ec_resume,
367 .ec_cmd = olpc_xo1_ec_cmd,
368 };
369
370 static struct olpc_ec_driver ec_xo1_5_driver = {
371 .probe = olpc_xo1_ec_probe,
372 .ec_cmd = olpc_xo1_ec_cmd,
373 };
374
olpc_init(void)375 static int __init olpc_init(void)
376 {
377 int r = 0;
378
379 if (!olpc_ofw_present() || !platform_detect())
380 return 0;
381
382 /* register the XO-1 and 1.5-specific EC handler */
383 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) /* XO-1 */
384 olpc_ec_driver_register(&ec_xo1_driver, NULL);
385 else
386 olpc_ec_driver_register(&ec_xo1_5_driver, NULL);
387 platform_device_register_simple("olpc-ec", -1, NULL, 0);
388
389 /* assume B1 and above models always have a DCON */
390 if (olpc_board_at_least(olpc_board(0xb1)))
391 olpc_platform_info.flags |= OLPC_F_DCON;
392
393 #ifdef CONFIG_PCI_OLPC
394 /* If the VSA exists let it emulate PCI, if not emulate in kernel.
395 * XO-1 only. */
396 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) &&
397 !cs5535_has_vsa2())
398 x86_init.pci.arch_init = pci_olpc_init;
399 #endif
400
401 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */
402 r = add_xo1_platform_devices();
403 if (r)
404 return r;
405 }
406
407 return 0;
408 }
409
410 postcore_initcall(olpc_init);
411