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 22 #include <asm/geode.h> 23 #include <asm/setup.h> 24 #include <asm/olpc.h> 25 #include <asm/olpc_ofw.h> 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 int restarts = 0; 119 120 spin_lock_irqsave(&ec_lock, flags); 121 122 /* Clear OBF */ 123 for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++) 124 inb(0x68); 125 if (i == 10) { 126 printk(KERN_ERR "olpc-ec: timeout while attempting to " 127 "clear OBF flag!\n"); 128 goto err; 129 } 130 131 if (wait_on_ibf(0x6c, 0)) { 132 printk(KERN_ERR "olpc-ec: timeout waiting for EC to " 133 "quiesce!\n"); 134 goto err; 135 } 136 137 restart: 138 /* 139 * Note that if we time out during any IBF checks, that's a failure; 140 * we have to return. There's no way for the kernel to clear that. 141 * 142 * If we time out during an OBF check, we can restart the command; 143 * reissuing it will clear the OBF flag, and we should be alright. 144 * The OBF flag will sometimes misbehave due to what we believe 145 * is a hardware quirk.. 146 */ 147 pr_devel("olpc-ec: running cmd 0x%x\n", cmd); 148 outb(cmd, 0x6c); 149 150 if (wait_on_ibf(0x6c, 0)) { 151 printk(KERN_ERR "olpc-ec: timeout waiting for EC to read " 152 "command!\n"); 153 goto err; 154 } 155 156 if (inbuf && inlen) { 157 /* write data to EC */ 158 for (i = 0; i < inlen; i++) { 159 if (wait_on_ibf(0x6c, 0)) { 160 printk(KERN_ERR "olpc-ec: timeout waiting for" 161 " EC accept data!\n"); 162 goto err; 163 } 164 pr_devel("olpc-ec: sending cmd arg 0x%x\n", 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 if (restarts++ < 10) 175 goto restart; 176 goto err; 177 } 178 outbuf[i] = inb(0x68); 179 pr_devel("olpc-ec: received 0x%x\n", outbuf[i]); 180 } 181 } 182 183 ret = 0; 184 err: 185 spin_unlock_irqrestore(&ec_lock, flags); 186 return ret; 187 } 188 EXPORT_SYMBOL_GPL(olpc_ec_cmd); 189 190 static bool __init check_ofw_architecture(void) 191 { 192 size_t propsize; 193 char olpc_arch[5]; 194 const void *args[] = { NULL, "architecture", olpc_arch, (void *)5 }; 195 void *res[] = { &propsize }; 196 197 if (olpc_ofw("getprop", args, res)) { 198 printk(KERN_ERR "ofw: getprop call failed!\n"); 199 return false; 200 } 201 return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0; 202 } 203 204 static u32 __init get_board_revision(void) 205 { 206 size_t propsize; 207 __be32 rev; 208 const void *args[] = { NULL, "board-revision-int", &rev, (void *)4 }; 209 void *res[] = { &propsize }; 210 211 if (olpc_ofw("getprop", args, res) || propsize != 4) { 212 printk(KERN_ERR "ofw: getprop call failed!\n"); 213 return cpu_to_be32(0); 214 } 215 return be32_to_cpu(rev); 216 } 217 218 static bool __init platform_detect(void) 219 { 220 if (!check_ofw_architecture()) 221 return false; 222 olpc_platform_info.flags |= OLPC_F_PRESENT; 223 olpc_platform_info.boardrev = get_board_revision(); 224 return true; 225 } 226 227 static int __init add_xo1_platform_devices(void) 228 { 229 struct platform_device *pdev; 230 231 pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0); 232 if (IS_ERR(pdev)) 233 return PTR_ERR(pdev); 234 235 pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0); 236 if (IS_ERR(pdev)) 237 return PTR_ERR(pdev); 238 239 return 0; 240 } 241 242 static int __init olpc_init(void) 243 { 244 int r = 0; 245 246 if (!olpc_ofw_present() || !platform_detect()) 247 return 0; 248 249 spin_lock_init(&ec_lock); 250 251 /* assume B1 and above models always have a DCON */ 252 if (olpc_board_at_least(olpc_board(0xb1))) 253 olpc_platform_info.flags |= OLPC_F_DCON; 254 255 /* get the EC revision */ 256 olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0, 257 (unsigned char *) &olpc_platform_info.ecver, 1); 258 259 #ifdef CONFIG_PCI_OLPC 260 /* If the VSA exists let it emulate PCI, if not emulate in kernel. 261 * XO-1 only. */ 262 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) && 263 !cs5535_has_vsa2()) 264 x86_init.pci.arch_init = pci_olpc_init; 265 #endif 266 267 printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n", 268 ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "", 269 olpc_platform_info.boardrev >> 4, 270 olpc_platform_info.ecver); 271 272 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */ 273 r = add_xo1_platform_devices(); 274 if (r) 275 return r; 276 } 277 278 return 0; 279 } 280 281 postcore_initcall(olpc_init); 282