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/export.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 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 59 static inline unsigned int ibf_status(unsigned int port) 60 { 61 return !!(inb(port) & 0x02); 62 } 63 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)) 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)) 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 */ 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 } 188 189 void olpc_ec_wakeup_set(u16 value) 190 { 191 ec_wakeup_mask |= value; 192 } 193 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_set); 194 195 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 */ 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); 231 232 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); 244 245 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); 265 266 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 } 274 275 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 } 286 287 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 } 304 305 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 } 319 320 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 } 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 } 347 348 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 }; 374 375 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