|
| 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 <asm/geode.h> |
| 21 | +#include <asm/olpc.h> |
| 22 | + |
| 23 | +#ifdef CONFIG_OPEN_FIRMWARE |
| 24 | +#include <asm/ofw.h> |
| 25 | +#endif |
| 26 | + |
| 27 | +struct olpc_platform_t olpc_platform_info; |
| 28 | +EXPORT_SYMBOL_GPL(olpc_platform_info); |
| 29 | + |
| 30 | +static DEFINE_SPINLOCK(ec_lock); |
| 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 | +int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen, |
| 113 | + unsigned char *outbuf, size_t outlen) |
| 114 | +{ |
| 115 | + unsigned long flags; |
| 116 | + int ret = -EIO; |
| 117 | + int i; |
| 118 | + |
| 119 | + spin_lock_irqsave(&ec_lock, flags); |
| 120 | + |
| 121 | + /* Clear OBF */ |
| 122 | + for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++) |
| 123 | + inb(0x68); |
| 124 | + if (i == 10) { |
| 125 | + printk(KERN_ERR "olpc-ec: timeout while attempting to " |
| 126 | + "clear OBF flag!\n"); |
| 127 | + goto err; |
| 128 | + } |
| 129 | + |
| 130 | + if (wait_on_ibf(0x6c, 0)) { |
| 131 | + printk(KERN_ERR "olpc-ec: timeout waiting for EC to " |
| 132 | + "quiesce!\n"); |
| 133 | + goto err; |
| 134 | + } |
| 135 | + |
| 136 | +restart: |
| 137 | + /* |
| 138 | + * Note that if we time out during any IBF checks, that's a failure; |
| 139 | + * we have to return. There's no way for the kernel to clear that. |
| 140 | + * |
| 141 | + * If we time out during an OBF check, we can restart the command; |
| 142 | + * reissuing it will clear the OBF flag, and we should be alright. |
| 143 | + * The OBF flag will sometimes misbehave due to what we believe |
| 144 | + * is a hardware quirk.. |
| 145 | + */ |
| 146 | + printk(KERN_DEBUG "olpc-ec: running cmd 0x%x\n", cmd); |
| 147 | + outb(cmd, 0x6c); |
| 148 | + |
| 149 | + if (wait_on_ibf(0x6c, 0)) { |
| 150 | + printk(KERN_ERR "olpc-ec: timeout waiting for EC to read " |
| 151 | + "command!\n"); |
| 152 | + goto err; |
| 153 | + } |
| 154 | + |
| 155 | + if (inbuf && inlen) { |
| 156 | + /* write data to EC */ |
| 157 | + for (i = 0; i < inlen; i++) { |
| 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 | + printk(KERN_DEBUG "olpc-ec: sending cmd arg 0x%x\n", |
| 164 | + inbuf[i]); |
| 165 | + outb(inbuf[i], 0x68); |
| 166 | + } |
| 167 | + } |
| 168 | + if (outbuf && outlen) { |
| 169 | + /* read data from EC */ |
| 170 | + for (i = 0; i < outlen; i++) { |
| 171 | + if (wait_on_obf(0x6c, 1)) { |
| 172 | + printk(KERN_ERR "olpc-ec: timeout waiting for" |
| 173 | + " EC to provide data!\n"); |
| 174 | + goto restart; |
| 175 | + } |
| 176 | + outbuf[i] = inb(0x68); |
| 177 | + printk(KERN_DEBUG "olpc-ec: received 0x%x\n", |
| 178 | + outbuf[i]); |
| 179 | + } |
| 180 | + } |
| 181 | + |
| 182 | + ret = 0; |
| 183 | +err: |
| 184 | + spin_unlock_irqrestore(&ec_lock, flags); |
| 185 | + return ret; |
| 186 | +} |
| 187 | +EXPORT_SYMBOL_GPL(olpc_ec_cmd); |
| 188 | + |
| 189 | +#ifdef CONFIG_OPEN_FIRMWARE |
| 190 | +static void __init platform_detect(void) |
| 191 | +{ |
| 192 | + size_t propsize; |
| 193 | + u32 rev; |
| 194 | + |
| 195 | + if (ofw("getprop", 4, 1, NULL, "board-revision-int", &rev, 4, |
| 196 | + &propsize) || propsize != 4) { |
| 197 | + printk(KERN_ERR "ofw: getprop call failed!\n"); |
| 198 | + rev = 0; |
| 199 | + } |
| 200 | + olpc_platform_info.boardrev = be32_to_cpu(rev); |
| 201 | +} |
| 202 | +#else |
| 203 | +static void __init platform_detect(void) |
| 204 | +{ |
| 205 | + /* stopgap until OFW support is added to the kernel */ |
| 206 | + olpc_platform_info.boardrev = be32_to_cpu(0xc2); |
| 207 | +} |
| 208 | +#endif |
| 209 | + |
| 210 | +static int __init olpc_init(void) |
| 211 | +{ |
| 212 | + unsigned char *romsig; |
| 213 | + |
| 214 | + /* The ioremap check is dangerous; limit what we run it on */ |
| 215 | + if (!is_geode() || geode_has_vsa2()) |
| 216 | + return 0; |
| 217 | + |
| 218 | + spin_lock_init(&ec_lock); |
| 219 | + |
| 220 | + romsig = ioremap(0xffffffc0, 16); |
| 221 | + if (!romsig) |
| 222 | + return 0; |
| 223 | + |
| 224 | + if (strncmp(romsig, "CL1 Q", 7)) |
| 225 | + goto unmap; |
| 226 | + if (strncmp(romsig+6, romsig+13, 3)) { |
| 227 | + printk(KERN_INFO "OLPC BIOS signature looks invalid. " |
| 228 | + "Assuming not OLPC\n"); |
| 229 | + goto unmap; |
| 230 | + } |
| 231 | + |
| 232 | + printk(KERN_INFO "OLPC board with OpenFirmware %.16s\n", romsig); |
| 233 | + olpc_platform_info.flags |= OLPC_F_PRESENT; |
| 234 | + |
| 235 | + /* get the platform revision */ |
| 236 | + platform_detect(); |
| 237 | + |
| 238 | + /* assume B1 and above models always have a DCON */ |
| 239 | + if (olpc_board_at_least(olpc_board(0xb1))) |
| 240 | + olpc_platform_info.flags |= OLPC_F_DCON; |
| 241 | + |
| 242 | + /* get the EC revision */ |
| 243 | + olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0, |
| 244 | + (unsigned char *) &olpc_platform_info.ecver, 1); |
| 245 | + |
| 246 | + /* check to see if the VSA exists */ |
| 247 | + if (geode_has_vsa2()) |
| 248 | + olpc_platform_info.flags |= OLPC_F_VSA; |
| 249 | + |
| 250 | + printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n", |
| 251 | + ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "", |
| 252 | + olpc_platform_info.boardrev >> 4, |
| 253 | + olpc_platform_info.ecver); |
| 254 | + |
| 255 | +unmap: |
| 256 | + iounmap(romsig); |
| 257 | + return 0; |
| 258 | +} |
| 259 | + |
| 260 | +postcore_initcall(olpc_init); |
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