arch/x86/platform/olpc/olpc.c

   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
  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);