arch/x86/platform/olpc/olpc.c

   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);