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/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                         pr_devel("olpc-ec:  sending cmd arg 0x%x\n", inbuf[i]);
 165                         outb(inbuf[i], 0x68);
 166                         if (wait_on_ibf(0x6c, 0)) {
 167                                 printk(KERN_ERR "olpc-ec:  timeout waiting for"
 168                                                 " EC accept data!\n");
 169                                 goto err;
 170                         }
 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         /*
 226          * XO-1.5 EC wakeups are available when olpc-xo15-sci driver is
 227          * compiled in
 228          */
 229 #ifdef CONFIG_OLPC_XO15_SCI
 230         if (olpc_platform_info.boardrev >= olpc_board_pre(0xd0)) /* XO-1.5 */
 231                 return true;
 232 #endif
 233
 234         return false;
 235 }
 236 EXPORT_SYMBOL_GPL(olpc_ec_wakeup_available);
 237
 238 int olpc_ec_mask_write(u16 bits)
 239 {
 240         if (olpc_platform_info.flags & OLPC_F_EC_WIDE_SCI) {
 241                 __be16 ec_word = cpu_to_be16(bits);
 242                 return olpc_ec_cmd(EC_WRITE_EXT_SCI_MASK, (void *) &ec_word, 2,
 243                                    NULL, 0);
 244         } else {
 245                 unsigned char ec_byte = bits & 0xff;
 246                 return olpc_ec_cmd(EC_WRITE_SCI_MASK, &ec_byte, 1, NULL, 0);
 247         }
 248 }
 249 EXPORT_SYMBOL_GPL(olpc_ec_mask_write);
 250
 251 int olpc_ec_sci_query(u16 *sci_value)
 252 {
 253         int ret;
 254
 255         if (olpc_platform_info.flags & OLPC_F_EC_WIDE_SCI) {
 256                 __be16 ec_word;
 257                 ret = olpc_ec_cmd(EC_EXT_SCI_QUERY,
 258                         NULL, 0, (void *) &ec_word, 2);
 259                 if (ret == 0)
 260                         *sci_value = be16_to_cpu(ec_word);
 261         } else {
 262                 unsigned char ec_byte;
 263                 ret = olpc_ec_cmd(EC_SCI_QUERY, NULL, 0, &ec_byte, 1);
 264                 if (ret == 0)
 265                         *sci_value = ec_byte;
 266         }
 267
 268         return ret;
 269 }
 270 EXPORT_SYMBOL_GPL(olpc_ec_sci_query);
 271
 272 static int olpc_ec_suspend(void)
 273 {
 274         return olpc_ec_mask_write(ec_wakeup_mask);
 275 }
 276
 277 static bool __init check_ofw_architecture(struct device_node *root)
 278 {
 279         const char *olpc_arch;
 280         int propsize;
 281
 282         olpc_arch = of_get_property(root, "architecture", &propsize);
 283         return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0;
 284 }
 285
 286 static u32 __init get_board_revision(struct device_node *root)
 287 {
 288         int propsize;
 289         const __be32 *rev;
 290
 291         rev = of_get_property(root, "board-revision-int", &propsize);
 292         if (propsize != 4)
 293                 return 0;
 294
 295         return be32_to_cpu(*rev);
 296 }
 297
 298 static bool __init platform_detect(void)
 299 {
 300         struct device_node *root = of_find_node_by_path("/");
 301         bool success;
 302
 303         if (!root)
 304                 return false;
 305
 306         success = check_ofw_architecture(root);
 307         if (success) {
 308                 olpc_platform_info.boardrev = get_board_revision(root);
 309                 olpc_platform_info.flags |= OLPC_F_PRESENT;
 310         }
 311
 312         of_node_put(root);
 313         return success;
 314 }
 315
 316 static int __init add_xo1_platform_devices(void)
 317 {
 318         struct platform_device *pdev;
 319
 320         pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0);
 321         if (IS_ERR(pdev))
 322                 return PTR_ERR(pdev);
 323
 324         pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0);
 325         if (IS_ERR(pdev))
 326                 return PTR_ERR(pdev);
 327
 328         return 0;
 329 }
 330
 331 static struct syscore_ops olpc_syscore_ops = {
 332         .suspend = olpc_ec_suspend,
 333 };
 334
 335 static int __init olpc_init(void)
 336 {
 337         int r = 0;
 338
 339         if (!olpc_ofw_present() || !platform_detect())
 340                 return 0;
 341
 342         spin_lock_init(&ec_lock);
 343
 344         /* assume B1 and above models always have a DCON */
 345         if (olpc_board_at_least(olpc_board(0xb1)))
 346                 olpc_platform_info.flags |= OLPC_F_DCON;
 347
 348         /* get the EC revision */
 349         olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0,
 350                         (unsigned char *) &olpc_platform_info.ecver, 1);
 351
 352 #ifdef CONFIG_PCI_OLPC
 353         /* If the VSA exists let it emulate PCI, if not emulate in kernel.
 354          * XO-1 only. */
 355         if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) &&
 356                         !cs5535_has_vsa2())
 357                 x86_init.pci.arch_init = pci_olpc_init;
 358 #endif
 359         /* EC version 0x5f adds support for wide SCI mask */
 360         if (olpc_platform_info.ecver >= 0x5f)
 361                 olpc_platform_info.flags |= OLPC_F_EC_WIDE_SCI;
 362
 363         printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n",
 364                         ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "",
 365                         olpc_platform_info.boardrev >> 4,
 366                         olpc_platform_info.ecver);
 367
 368         if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */
 369                 r = add_xo1_platform_devices();
 370                 if (r)
 371                         return r;
 372         }
 373
 374         register_syscore_ops(&olpc_syscore_ops);
 375
 376         return 0;
 377 }
 378
 379 postcore_initcall(olpc_init);