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 /* what the timeout *should* be (in ms) */ 30 #define EC_BASE_TIMEOUT 20 31 32 /* the timeout that bugs in the EC might force us to actually use */ 33 static int ec_timeout = EC_BASE_TIMEOUT; 34 35 static int __init olpc_ec_timeout_set(char *str) 36 { 37 if (get_option(&str, &ec_timeout) != 1) { 38 ec_timeout = EC_BASE_TIMEOUT; 39 printk(KERN_ERR "olpc-ec: invalid argument to " 40 "'olpc_ec_timeout=', ignoring!\n"); 41 } 42 printk(KERN_DEBUG "olpc-ec: using %d ms delay for EC commands.\n", 43 ec_timeout); 44 return 1; 45 } 46 __setup("olpc_ec_timeout=", olpc_ec_timeout_set); 47 48 /* 49 * These {i,o}bf_status functions return whether the buffers are full or not. 50 */ 51 52 static inline unsigned int ibf_status(unsigned int port) 53 { 54 return !!(inb(port) & 0x02); 55 } 56 57 static inline unsigned int obf_status(unsigned int port) 58 { 59 return inb(port) & 0x01; 60 } 61 62 #define wait_on_ibf(p, d) __wait_on_ibf(__LINE__, (p), (d)) 63 static int __wait_on_ibf(unsigned int line, unsigned int port, int desired) 64 { 65 unsigned int timeo; 66 int state = ibf_status(port); 67 68 for (timeo = ec_timeout; state != desired && timeo; timeo--) { 69 mdelay(1); 70 state = ibf_status(port); 71 } 72 73 if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) && 74 timeo < (ec_timeout - EC_BASE_TIMEOUT)) { 75 printk(KERN_WARNING "olpc-ec: %d: waited %u ms for IBF!\n", 76 line, ec_timeout - timeo); 77 } 78 79 return !(state == desired); 80 } 81 82 #define wait_on_obf(p, d) __wait_on_obf(__LINE__, (p), (d)) 83 static int __wait_on_obf(unsigned int line, unsigned int port, int desired) 84 { 85 unsigned int timeo; 86 int state = obf_status(port); 87 88 for (timeo = ec_timeout; state != desired && timeo; timeo--) { 89 mdelay(1); 90 state = obf_status(port); 91 } 92 93 if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) && 94 timeo < (ec_timeout - EC_BASE_TIMEOUT)) { 95 printk(KERN_WARNING "olpc-ec: %d: waited %u ms for OBF!\n", 96 line, ec_timeout - timeo); 97 } 98 99 return !(state == desired); 100 } 101 102 /* 103 * This allows the kernel to run Embedded Controller commands. The EC is 104 * documented at <http://wiki.laptop.org/go/Embedded_controller>, and the 105 * available EC commands are here: 106 * <http://wiki.laptop.org/go/Ec_specification>. Unfortunately, while 107 * OpenFirmware's source is available, the EC's is not. 108 */ 109 static int olpc_xo1_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf, 110 size_t outlen, void *arg) 111 { 112 int ret = -EIO; 113 int i; 114 int restarts = 0; 115 116 /* Clear OBF */ 117 for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++) 118 inb(0x68); 119 if (i == 10) { 120 printk(KERN_ERR "olpc-ec: timeout while attempting to " 121 "clear OBF flag!\n"); 122 goto err; 123 } 124 125 if (wait_on_ibf(0x6c, 0)) { 126 printk(KERN_ERR "olpc-ec: timeout waiting for EC to " 127 "quiesce!\n"); 128 goto err; 129 } 130 131 restart: 132 /* 133 * Note that if we time out during any IBF checks, that's a failure; 134 * we have to return. There's no way for the kernel to clear that. 135 * 136 * If we time out during an OBF check, we can restart the command; 137 * reissuing it will clear the OBF flag, and we should be alright. 138 * The OBF flag will sometimes misbehave due to what we believe 139 * is a hardware quirk.. 140 */ 141 pr_devel("olpc-ec: running cmd 0x%x\n", cmd); 142 outb(cmd, 0x6c); 143 144 if (wait_on_ibf(0x6c, 0)) { 145 printk(KERN_ERR "olpc-ec: timeout waiting for EC to read " 146 "command!\n"); 147 goto err; 148 } 149 150 if (inbuf && inlen) { 151 /* write data to EC */ 152 for (i = 0; i < inlen; i++) { 153 pr_devel("olpc-ec: sending cmd arg 0x%x\n", inbuf[i]); 154 outb(inbuf[i], 0x68); 155 if (wait_on_ibf(0x6c, 0)) { 156 printk(KERN_ERR "olpc-ec: timeout waiting for" 157 " EC accept data!\n"); 158 goto err; 159 } 160 } 161 } 162 if (outbuf && outlen) { 163 /* read data from EC */ 164 for (i = 0; i < outlen; i++) { 165 if (wait_on_obf(0x6c, 1)) { 166 printk(KERN_ERR "olpc-ec: timeout waiting for" 167 " EC to provide data!\n"); 168 if (restarts++ < 10) 169 goto restart; 170 goto err; 171 } 172 outbuf[i] = inb(0x68); 173 pr_devel("olpc-ec: received 0x%x\n", outbuf[i]); 174 } 175 } 176 177 ret = 0; 178 err: 179 return ret; 180 } 181 182 static bool __init check_ofw_architecture(struct device_node *root) 183 { 184 const char *olpc_arch; 185 int propsize; 186 187 olpc_arch = of_get_property(root, "architecture", &propsize); 188 return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0; 189 } 190 191 static u32 __init get_board_revision(struct device_node *root) 192 { 193 int propsize; 194 const __be32 *rev; 195 196 rev = of_get_property(root, "board-revision-int", &propsize); 197 if (propsize != 4) 198 return 0; 199 200 return be32_to_cpu(*rev); 201 } 202 203 static bool __init platform_detect(void) 204 { 205 struct device_node *root = of_find_node_by_path("/"); 206 bool success; 207 208 if (!root) 209 return false; 210 211 success = check_ofw_architecture(root); 212 if (success) { 213 olpc_platform_info.boardrev = get_board_revision(root); 214 olpc_platform_info.flags |= OLPC_F_PRESENT; 215 216 pr_info("OLPC board revision %s%X\n", 217 ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "", 218 olpc_platform_info.boardrev >> 4); 219 } 220 221 of_node_put(root); 222 return success; 223 } 224 225 static int __init add_xo1_platform_devices(void) 226 { 227 struct platform_device *pdev; 228 229 pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0); 230 if (IS_ERR(pdev)) 231 return PTR_ERR(pdev); 232 233 pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0); 234 235 return PTR_ERR_OR_ZERO(pdev); 236 } 237 238 static int olpc_xo1_ec_suspend(struct platform_device *pdev) 239 { 240 /* 241 * Squelch SCIs while suspended. This is a fix for 242 * <http://dev.laptop.org/ticket/1835>. 243 */ 244 return olpc_ec_cmd(EC_SET_SCI_INHIBIT, NULL, 0, NULL, 0); 245 } 246 247 static int olpc_xo1_ec_resume(struct platform_device *pdev) 248 { 249 /* Tell the EC to stop inhibiting SCIs */ 250 olpc_ec_cmd(EC_SET_SCI_INHIBIT_RELEASE, NULL, 0, NULL, 0); 251 252 /* 253 * Tell the wireless module to restart USB communication. 254 * Must be done twice. 255 */ 256 olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0); 257 olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0); 258 259 return 0; 260 } 261 262 static struct olpc_ec_driver ec_xo1_driver = { 263 .suspend = olpc_xo1_ec_suspend, 264 .resume = olpc_xo1_ec_resume, 265 .ec_cmd = olpc_xo1_ec_cmd, 266 #ifdef CONFIG_OLPC_XO1_SCI 267 /* 268 * XO-1 EC wakeups are available when olpc-xo1-sci driver is 269 * compiled in 270 */ 271 .wakeup_available = true, 272 #endif 273 }; 274 275 static struct olpc_ec_driver ec_xo1_5_driver = { 276 .ec_cmd = olpc_xo1_ec_cmd, 277 #ifdef CONFIG_OLPC_XO15_SCI 278 /* 279 * XO-1.5 EC wakeups are available when olpc-xo15-sci driver is 280 * compiled in 281 */ 282 .wakeup_available = true, 283 #endif 284 }; 285 286 static int __init olpc_init(void) 287 { 288 int r = 0; 289 290 if (!olpc_ofw_present() || !platform_detect()) 291 return 0; 292 293 /* register the XO-1 and 1.5-specific EC handler */ 294 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) /* XO-1 */ 295 olpc_ec_driver_register(&ec_xo1_driver, NULL); 296 else 297 olpc_ec_driver_register(&ec_xo1_5_driver, NULL); 298 platform_device_register_simple("olpc-ec", -1, NULL, 0); 299 300 /* assume B1 and above models always have a DCON */ 301 if (olpc_board_at_least(olpc_board(0xb1))) 302 olpc_platform_info.flags |= OLPC_F_DCON; 303 304 #ifdef CONFIG_PCI_OLPC 305 /* If the VSA exists let it emulate PCI, if not emulate in kernel. 306 * XO-1 only. */ 307 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) && 308 !cs5535_has_vsa2()) 309 x86_init.pci.arch_init = pci_olpc_init; 310 #endif 311 312 if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */ 313 r = add_xo1_platform_devices(); 314 if (r) 315 return r; 316 } 317 318 return 0; 319 } 320 321 postcore_initcall(olpc_init); 322