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 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 60 static inline unsigned int ibf_status(unsigned int port) 61 { 62 return !!(inb(port) & 0x02); 63 } 64 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)) 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)) 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 */ 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 if (wait_on_ibf(0x6c, 0)) { 165 printk(KERN_ERR "olpc-ec: timeout waiting for" 166 " EC accept data!\n"); 167 goto err; 168 } 169 pr_devel("olpc-ec: sending cmd arg 0x%x\n", inbuf[i]); 170 outb(inbuf[i], 0x68); 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); 194 195 void olpc_ec_wakeup_set(u16 value) 196 { 197 ec_wakeup_mask |= value; 198 } 199 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_set); 200 201 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 */ 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 return false; 226 } 227 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_available); 228 229 int olpc_ec_mask_write(u16 bits) 230 { 231 if (olpc_platform_info.flags & OLPC_F_EC_WIDE_SCI) { 232 __be16 ec_word = cpu_to_be16(bits); 233 return olpc_ec_cmd(EC_WRITE_EXT_SCI_MASK, (void *) &ec_word, 2, 234 NULL, 0); 235 } else { 236 unsigned char ec_byte = bits & 0xff; 237 return olpc_ec_cmd(EC_WRITE_SCI_MASK, &ec_byte, 1, NULL, 0); 238 } 239 } 240 EXPORT_SYMBOL_GPL(olpc_ec_mask_write); 241 242 int olpc_ec_sci_query(u16 *sci_value) 243 { 244 int ret; 245 246 if (olpc_platform_info.flags & OLPC_F_EC_WIDE_SCI) { 247 __be16 ec_word; 248 ret = olpc_ec_cmd(EC_EXT_SCI_QUERY, 249 NULL, 0, (void *) &ec_word, 2); 250 if (ret == 0) 251 *sci_value = be16_to_cpu(ec_word); 252 } else { 253 unsigned char ec_byte; 254 ret = olpc_ec_cmd(EC_SCI_QUERY, NULL, 0, &ec_byte, 1); 255 if (ret == 0) 256 *sci_value = ec_byte; 257 } 258 259 return ret; 260 } 261 EXPORT_SYMBOL_GPL(olpc_ec_sci_query); 262 263 static int olpc_ec_suspend(void) 264 { 265 return olpc_ec_mask_write(ec_wakeup_mask); 266 } 267 268 static bool __init check_ofw_architecture(struct device_node *root) 269 { 270 const char *olpc_arch; 271 int propsize; 272 273 olpc_arch = of_get_property(root, "architecture", &propsize); 274 return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0; 275 } 276 277 static u32 __init get_board_revision(struct device_node *root) 278 { 279 int propsize; 280 const __be32 *rev; 281 282 rev = of_get_property(root, "board-revision-int", &propsize); 283 if (propsize != 4) 284 return 0; 285 286 return be32_to_cpu(*rev); 287 } 288 289 static bool __init platform_detect(void) 290 { 291 struct device_node *root = of_find_node_by_path("/"); 292 bool success; 293 294 if (!root) 295 return false; 296 297 success = check_ofw_architecture(root); 298 if (success) { 299 olpc_platform_info.boardrev = get_board_revision(root); 300 olpc_platform_info.flags |= OLPC_F_PRESENT; 301 } 302 303 of_node_put(root); 304 return success; 305 } 306 307 static int __init add_xo1_platform_devices(void) 308 { 309 struct platform_device *pdev; 310 311 pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0); 312 if (IS_ERR(pdev)) 313 return PTR_ERR(pdev); 314 315 pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0); 316 if (IS_ERR(pdev)) 317 return PTR_ERR(pdev); 318 319 return 0; 320 } 321 322 static struct syscore_ops olpc_syscore_ops = { 323 .suspend = olpc_ec_suspend, 324 }; 325 326 static int __init olpc_init(void) 327 { 328 int r = 0; 329 330 if (!olpc_ofw_present() || !platform_detect()) 331 return 0; 332 333 spin_lock_init(&ec_lock); 334 335 /* assume B1 and above models always have a DCON */ 336 if (olpc_board_at_least(olpc_board(0xb1))) 337 olpc_platform_info.flags |= OLPC_F_DCON; 338 339 /* get the EC revision */ 340 olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0, 341 (unsigned char *) &olpc_platform_info.ecver, 1); 342 343 #ifdef CONFIG_PCI_OLPC 344 /* If the VSA exists let it emulate PCI, if not emulate in kernel. 345 * XO-1 only. */ 346 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) && 347 !cs5535_has_vsa2()) 348 x86_init.pci.arch_init = pci_olpc_init; 349 #endif 350 /* EC version 0x5f adds support for wide SCI mask */ 351 if (olpc_platform_info.ecver >= 0x5f) 352 olpc_platform_info.flags |= OLPC_F_EC_WIDE_SCI; 353 354 printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n", 355 ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "", 356 olpc_platform_info.boardrev >> 4, 357 olpc_platform_info.ecver); 358 359 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */ 360 r = add_xo1_platform_devices(); 361 if (r) 362 return r; 363 } 364 365 register_syscore_ops(&olpc_syscore_ops); 366 367 return 0; 368 } 369 370 postcore_initcall(olpc_init); 371