1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Support for the OLPC DCON and OLPC EC access 4 * 5 * Copyright © 2006 Advanced Micro Devices, Inc. 6 * Copyright © 2007-2008 Andres Salomon <dilinger@debian.org> 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/init.h> 11 #include <linux/export.h> 12 #include <linux/delay.h> 13 #include <linux/io.h> 14 #include <linux/string.h> 15 #include <linux/platform_device.h> 16 #include <linux/of.h> 17 #include <linux/syscore_ops.h> 18 #include <linux/mutex.h> 19 #include <linux/olpc-ec.h> 20 21 #include <asm/geode.h> 22 #include <asm/setup.h> 23 #include <asm/olpc.h> 24 #include <asm/olpc_ofw.h> 25 26 struct olpc_platform_t olpc_platform_info; 27 EXPORT_SYMBOL_GPL(olpc_platform_info); 28 29 /* EC event mask to be applied during suspend (defining wakeup sources). */ 30 static u16 ec_wakeup_mask; 31 32 /* what the timeout *should* be (in ms) */ 33 #define EC_BASE_TIMEOUT 20 34 35 /* the timeout that bugs in the EC might force us to actually use */ 36 static int ec_timeout = EC_BASE_TIMEOUT; 37 38 static int __init olpc_ec_timeout_set(char *str) 39 { 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"); 44 } 45 printk(KERN_DEBUG "olpc-ec: using %d ms delay for EC commands.\n", 46 ec_timeout); 47 return 1; 48 } 49 __setup("olpc_ec_timeout=", olpc_ec_timeout_set); 50 51 /* 52 * These {i,o}bf_status functions return whether the buffers are full or not. 53 */ 54 55 static inline unsigned int ibf_status(unsigned int port) 56 { 57 return !!(inb(port) & 0x02); 58 } 59 60 static inline unsigned int obf_status(unsigned int port) 61 { 62 return inb(port) & 0x01; 63 } 64 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) 67 { 68 unsigned int timeo; 69 int state = ibf_status(port); 70 71 for (timeo = ec_timeout; state != desired && timeo; timeo--) { 72 mdelay(1); 73 state = ibf_status(port); 74 } 75 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); 80 } 81 82 return !(state == desired); 83 } 84 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) 87 { 88 unsigned int timeo; 89 int state = obf_status(port); 90 91 for (timeo = ec_timeout; state != desired && timeo; timeo--) { 92 mdelay(1); 93 state = obf_status(port); 94 } 95 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); 100 } 101 102 return !(state == desired); 103 } 104 105 /* 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. 111 */ 112 static int olpc_xo1_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf, 113 size_t outlen, void *arg) 114 { 115 int ret = -EIO; 116 int i; 117 int restarts = 0; 118 119 /* Clear OBF */ 120 for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++) 121 inb(0x68); 122 if (i == 10) { 123 printk(KERN_ERR "olpc-ec: timeout while attempting to " 124 "clear OBF flag!\n"); 125 goto err; 126 } 127 128 if (wait_on_ibf(0x6c, 0)) { 129 printk(KERN_ERR "olpc-ec: timeout waiting for EC to " 130 "quiesce!\n"); 131 goto err; 132 } 133 134 restart: 135 /* 136 * Note that if we time out during any IBF checks, that's a failure; 137 * we have to return. There's no way for the kernel to clear that. 138 * 139 * If we time out during an OBF check, we can restart the command; 140 * reissuing it will clear the OBF flag, and we should be alright. 141 * The OBF flag will sometimes misbehave due to what we believe 142 * is a hardware quirk.. 143 */ 144 pr_devel("olpc-ec: running cmd 0x%x\n", cmd); 145 outb(cmd, 0x6c); 146 147 if (wait_on_ibf(0x6c, 0)) { 148 printk(KERN_ERR "olpc-ec: timeout waiting for EC to read " 149 "command!\n"); 150 goto err; 151 } 152 153 if (inbuf && inlen) { 154 /* write data to EC */ 155 for (i = 0; i < inlen; i++) { 156 pr_devel("olpc-ec: sending cmd arg 0x%x\n", inbuf[i]); 157 outb(inbuf[i], 0x68); 158 if (wait_on_ibf(0x6c, 0)) { 159 printk(KERN_ERR "olpc-ec: timeout waiting for" 160 " EC accept data!\n"); 161 goto err; 162 } 163 } 164 } 165 if (outbuf && outlen) { 166 /* read data from EC */ 167 for (i = 0; i < outlen; i++) { 168 if (wait_on_obf(0x6c, 1)) { 169 printk(KERN_ERR "olpc-ec: timeout waiting for" 170 " EC to provide data!\n"); 171 if (restarts++ < 10) 172 goto restart; 173 goto err; 174 } 175 outbuf[i] = inb(0x68); 176 pr_devel("olpc-ec: received 0x%x\n", outbuf[i]); 177 } 178 } 179 180 ret = 0; 181 err: 182 return ret; 183 } 184 185 void olpc_ec_wakeup_set(u16 value) 186 { 187 ec_wakeup_mask |= value; 188 } 189 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_set); 190 191 void olpc_ec_wakeup_clear(u16 value) 192 { 193 ec_wakeup_mask &= ~value; 194 } 195 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_clear); 196 197 /* 198 * Returns true if the compile and runtime configurations allow for EC events 199 * to wake the system. 200 */ 201 bool olpc_ec_wakeup_available(void) 202 { 203 if (!machine_is_olpc()) 204 return false; 205 206 /* 207 * XO-1 EC wakeups are available when olpc-xo1-sci driver is 208 * compiled in 209 */ 210 #ifdef CONFIG_OLPC_XO1_SCI 211 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) /* XO-1 */ 212 return true; 213 #endif 214 215 /* 216 * XO-1.5 EC wakeups are available when olpc-xo15-sci driver is 217 * compiled in 218 */ 219 #ifdef CONFIG_OLPC_XO15_SCI 220 if (olpc_platform_info.boardrev >= olpc_board_pre(0xd0)) /* XO-1.5 */ 221 return true; 222 #endif 223 224 return false; 225 } 226 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_available); 227 228 int olpc_ec_mask_write(u16 bits) 229 { 230 if (olpc_platform_info.flags & OLPC_F_EC_WIDE_SCI) { 231 __be16 ec_word = cpu_to_be16(bits); 232 return olpc_ec_cmd(EC_WRITE_EXT_SCI_MASK, (void *) &ec_word, 2, 233 NULL, 0); 234 } else { 235 unsigned char ec_byte = bits & 0xff; 236 return olpc_ec_cmd(EC_WRITE_SCI_MASK, &ec_byte, 1, NULL, 0); 237 } 238 } 239 EXPORT_SYMBOL_GPL(olpc_ec_mask_write); 240 241 int olpc_ec_sci_query(u16 *sci_value) 242 { 243 int ret; 244 245 if (olpc_platform_info.flags & OLPC_F_EC_WIDE_SCI) { 246 __be16 ec_word; 247 ret = olpc_ec_cmd(EC_EXT_SCI_QUERY, 248 NULL, 0, (void *) &ec_word, 2); 249 if (ret == 0) 250 *sci_value = be16_to_cpu(ec_word); 251 } else { 252 unsigned char ec_byte; 253 ret = olpc_ec_cmd(EC_SCI_QUERY, NULL, 0, &ec_byte, 1); 254 if (ret == 0) 255 *sci_value = ec_byte; 256 } 257 258 return ret; 259 } 260 EXPORT_SYMBOL_GPL(olpc_ec_sci_query); 261 262 static bool __init check_ofw_architecture(struct device_node *root) 263 { 264 const char *olpc_arch; 265 int propsize; 266 267 olpc_arch = of_get_property(root, "architecture", &propsize); 268 return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0; 269 } 270 271 static u32 __init get_board_revision(struct device_node *root) 272 { 273 int propsize; 274 const __be32 *rev; 275 276 rev = of_get_property(root, "board-revision-int", &propsize); 277 if (propsize != 4) 278 return 0; 279 280 return be32_to_cpu(*rev); 281 } 282 283 static bool __init platform_detect(void) 284 { 285 struct device_node *root = of_find_node_by_path("/"); 286 bool success; 287 288 if (!root) 289 return false; 290 291 success = check_ofw_architecture(root); 292 if (success) { 293 olpc_platform_info.boardrev = get_board_revision(root); 294 olpc_platform_info.flags |= OLPC_F_PRESENT; 295 } 296 297 of_node_put(root); 298 return success; 299 } 300 301 static int __init add_xo1_platform_devices(void) 302 { 303 struct platform_device *pdev; 304 305 pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0); 306 if (IS_ERR(pdev)) 307 return PTR_ERR(pdev); 308 309 pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0); 310 311 return PTR_ERR_OR_ZERO(pdev); 312 } 313 314 static int olpc_xo1_ec_probe(struct platform_device *pdev) 315 { 316 /* get the EC revision */ 317 olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0, 318 (unsigned char *) &olpc_platform_info.ecver, 1); 319 320 /* EC version 0x5f adds support for wide SCI mask */ 321 if (olpc_platform_info.ecver >= 0x5f) 322 olpc_platform_info.flags |= OLPC_F_EC_WIDE_SCI; 323 324 pr_info("OLPC board revision %s%X (EC=%x)\n", 325 ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "", 326 olpc_platform_info.boardrev >> 4, 327 olpc_platform_info.ecver); 328 329 return 0; 330 } 331 static int olpc_xo1_ec_suspend(struct platform_device *pdev) 332 { 333 olpc_ec_mask_write(ec_wakeup_mask); 334 335 /* 336 * Squelch SCIs while suspended. This is a fix for 337 * <http://dev.laptop.org/ticket/1835>. 338 */ 339 return olpc_ec_cmd(EC_SET_SCI_INHIBIT, NULL, 0, NULL, 0); 340 } 341 342 static int olpc_xo1_ec_resume(struct platform_device *pdev) 343 { 344 /* Tell the EC to stop inhibiting SCIs */ 345 olpc_ec_cmd(EC_SET_SCI_INHIBIT_RELEASE, NULL, 0, NULL, 0); 346 347 /* 348 * Tell the wireless module to restart USB communication. 349 * Must be done twice. 350 */ 351 olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0); 352 olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0); 353 354 return 0; 355 } 356 357 static struct olpc_ec_driver ec_xo1_driver = { 358 .probe = olpc_xo1_ec_probe, 359 .suspend = olpc_xo1_ec_suspend, 360 .resume = olpc_xo1_ec_resume, 361 .ec_cmd = olpc_xo1_ec_cmd, 362 }; 363 364 static struct olpc_ec_driver ec_xo1_5_driver = { 365 .probe = olpc_xo1_ec_probe, 366 .ec_cmd = olpc_xo1_ec_cmd, 367 }; 368 369 static int __init olpc_init(void) 370 { 371 int r = 0; 372 373 if (!olpc_ofw_present() || !platform_detect()) 374 return 0; 375 376 /* register the XO-1 and 1.5-specific EC handler */ 377 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) /* XO-1 */ 378 olpc_ec_driver_register(&ec_xo1_driver, NULL); 379 else 380 olpc_ec_driver_register(&ec_xo1_5_driver, NULL); 381 platform_device_register_simple("olpc-ec", -1, NULL, 0); 382 383 /* assume B1 and above models always have a DCON */ 384 if (olpc_board_at_least(olpc_board(0xb1))) 385 olpc_platform_info.flags |= OLPC_F_DCON; 386 387 #ifdef CONFIG_PCI_OLPC 388 /* If the VSA exists let it emulate PCI, if not emulate in kernel. 389 * XO-1 only. */ 390 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) && 391 !cs5535_has_vsa2()) 392 x86_init.pci.arch_init = pci_olpc_init; 393 #endif 394 395 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */ 396 r = add_xo1_platform_devices(); 397 if (r) 398 return r; 399 } 400 401 return 0; 402 } 403 404 postcore_initcall(olpc_init); 405