1 /*************************************************************************** 2 * Copyright (C) 2010-2011 Hans de Goede <hdegoede@redhat.com> * 3 * * 4 * This program is free software; you can redistribute it and/or modify * 5 * it under the terms of the GNU General Public License as published by * 6 * the Free Software Foundation; either version 2 of the License, or * 7 * (at your option) any later version. * 8 * * 9 * This program is distributed in the hope that it will be useful, * 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of * 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * 12 * GNU General Public License for more details. * 13 * * 14 * You should have received a copy of the GNU General Public License * 15 * along with this program; if not, write to the * 16 * Free Software Foundation, Inc., * 17 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * 18 ***************************************************************************/ 19 20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 21 22 #include <linux/module.h> 23 #include <linux/init.h> 24 #include <linux/platform_device.h> 25 #include <linux/err.h> 26 #include <linux/io.h> 27 #include <linux/acpi.h> 28 #include <linux/delay.h> 29 #include "sch56xx-common.h" 30 31 #define SIO_SCH56XX_LD_EM 0x0C /* Embedded uController Logical Dev */ 32 #define SIO_UNLOCK_KEY 0x55 /* Key to enable Super-I/O */ 33 #define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */ 34 35 #define SIO_REG_LDSEL 0x07 /* Logical device select */ 36 #define SIO_REG_DEVID 0x20 /* Device ID */ 37 #define SIO_REG_ENABLE 0x30 /* Logical device enable */ 38 #define SIO_REG_ADDR 0x66 /* Logical device address (2 bytes) */ 39 40 #define SIO_SCH5627_ID 0xC6 /* Chipset ID */ 41 #define SIO_SCH5636_ID 0xC7 /* Chipset ID */ 42 43 #define REGION_LENGTH 9 44 45 #define SCH56XX_CMD_READ 0x02 46 #define SCH56XX_CMD_WRITE 0x03 47 48 static struct platform_device *sch56xx_pdev; 49 50 /* Super I/O functions */ 51 static inline int superio_inb(int base, int reg) 52 { 53 outb(reg, base); 54 return inb(base + 1); 55 } 56 57 static inline int superio_enter(int base) 58 { 59 /* Don't step on other drivers' I/O space by accident */ 60 if (!request_muxed_region(base, 2, "sch56xx")) { 61 pr_err("I/O address 0x%04x already in use\n", base); 62 return -EBUSY; 63 } 64 65 outb(SIO_UNLOCK_KEY, base); 66 67 return 0; 68 } 69 70 static inline void superio_select(int base, int ld) 71 { 72 outb(SIO_REG_LDSEL, base); 73 outb(ld, base + 1); 74 } 75 76 static inline void superio_exit(int base) 77 { 78 outb(SIO_LOCK_KEY, base); 79 release_region(base, 2); 80 } 81 82 static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v) 83 { 84 u8 val; 85 int i; 86 /* 87 * According to SMSC for the commands we use the maximum time for 88 * the EM to respond is 15 ms, but testing shows in practice it 89 * responds within 15-32 reads, so we first busy poll, and if 90 * that fails sleep a bit and try again until we are way past 91 * the 15 ms maximum response time. 92 */ 93 const int max_busy_polls = 64; 94 const int max_lazy_polls = 32; 95 96 /* (Optional) Write-Clear the EC to Host Mailbox Register */ 97 val = inb(addr + 1); 98 outb(val, addr + 1); 99 100 /* Set Mailbox Address Pointer to first location in Region 1 */ 101 outb(0x00, addr + 2); 102 outb(0x80, addr + 3); 103 104 /* Write Request Packet Header */ 105 outb(cmd, addr + 4); /* VREG Access Type read:0x02 write:0x03 */ 106 outb(0x01, addr + 5); /* # of Entries: 1 Byte (8-bit) */ 107 outb(0x04, addr + 2); /* Mailbox AP to first data entry loc. */ 108 109 /* Write Value field */ 110 if (cmd == SCH56XX_CMD_WRITE) 111 outb(v, addr + 4); 112 113 /* Write Address field */ 114 outb(reg & 0xff, addr + 6); 115 outb(reg >> 8, addr + 7); 116 117 /* Execute the Random Access Command */ 118 outb(0x01, addr); /* Write 01h to the Host-to-EC register */ 119 120 /* EM Interface Polling "Algorithm" */ 121 for (i = 0; i < max_busy_polls + max_lazy_polls; i++) { 122 if (i >= max_busy_polls) 123 msleep(1); 124 /* Read Interrupt source Register */ 125 val = inb(addr + 8); 126 /* Write Clear the interrupt source bits */ 127 if (val) 128 outb(val, addr + 8); 129 /* Command Completed ? */ 130 if (val & 0x01) 131 break; 132 } 133 if (i == max_busy_polls + max_lazy_polls) { 134 pr_err("Max retries exceeded reading virtual " 135 "register 0x%04hx (%d)\n", reg, 1); 136 return -EIO; 137 } 138 139 /* 140 * According to SMSC we may need to retry this, but sofar I've always 141 * seen this succeed in 1 try. 142 */ 143 for (i = 0; i < max_busy_polls; i++) { 144 /* Read EC-to-Host Register */ 145 val = inb(addr + 1); 146 /* Command Completed ? */ 147 if (val == 0x01) 148 break; 149 150 if (i == 0) 151 pr_warn("EC reports: 0x%02x reading virtual register " 152 "0x%04hx\n", (unsigned int)val, reg); 153 } 154 if (i == max_busy_polls) { 155 pr_err("Max retries exceeded reading virtual " 156 "register 0x%04hx (%d)\n", reg, 2); 157 return -EIO; 158 } 159 160 /* 161 * According to the SMSC app note we should now do: 162 * 163 * Set Mailbox Address Pointer to first location in Region 1 * 164 * outb(0x00, addr + 2); 165 * outb(0x80, addr + 3); 166 * 167 * But if we do that things don't work, so let's not. 168 */ 169 170 /* Read Value field */ 171 if (cmd == SCH56XX_CMD_READ) 172 return inb(addr + 4); 173 174 return 0; 175 } 176 177 int sch56xx_read_virtual_reg(u16 addr, u16 reg) 178 { 179 return sch56xx_send_cmd(addr, SCH56XX_CMD_READ, reg, 0); 180 } 181 EXPORT_SYMBOL(sch56xx_read_virtual_reg); 182 183 int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val) 184 { 185 return sch56xx_send_cmd(addr, SCH56XX_CMD_WRITE, reg, val); 186 } 187 EXPORT_SYMBOL(sch56xx_write_virtual_reg); 188 189 int sch56xx_read_virtual_reg16(u16 addr, u16 reg) 190 { 191 int lsb, msb; 192 193 /* Read LSB first, this will cause the matching MSB to be latched */ 194 lsb = sch56xx_read_virtual_reg(addr, reg); 195 if (lsb < 0) 196 return lsb; 197 198 msb = sch56xx_read_virtual_reg(addr, reg + 1); 199 if (msb < 0) 200 return msb; 201 202 return lsb | (msb << 8); 203 } 204 EXPORT_SYMBOL(sch56xx_read_virtual_reg16); 205 206 int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg, 207 int high_nibble) 208 { 209 int msb, lsn; 210 211 /* Read MSB first, this will cause the matching LSN to be latched */ 212 msb = sch56xx_read_virtual_reg(addr, msb_reg); 213 if (msb < 0) 214 return msb; 215 216 lsn = sch56xx_read_virtual_reg(addr, lsn_reg); 217 if (lsn < 0) 218 return lsn; 219 220 if (high_nibble) 221 return (msb << 4) | (lsn >> 4); 222 else 223 return (msb << 4) | (lsn & 0x0f); 224 } 225 EXPORT_SYMBOL(sch56xx_read_virtual_reg12); 226 227 static int __init sch56xx_find(int sioaddr, unsigned short *address, 228 const char **name) 229 { 230 u8 devid; 231 int err; 232 233 err = superio_enter(sioaddr); 234 if (err) 235 return err; 236 237 devid = superio_inb(sioaddr, SIO_REG_DEVID); 238 switch (devid) { 239 case SIO_SCH5627_ID: 240 *name = "sch5627"; 241 break; 242 case SIO_SCH5636_ID: 243 *name = "sch5636"; 244 break; 245 default: 246 pr_debug("Unsupported device id: 0x%02x\n", 247 (unsigned int)devid); 248 err = -ENODEV; 249 goto exit; 250 } 251 252 superio_select(sioaddr, SIO_SCH56XX_LD_EM); 253 254 if (!(superio_inb(sioaddr, SIO_REG_ENABLE) & 0x01)) { 255 pr_warn("Device not activated\n"); 256 err = -ENODEV; 257 goto exit; 258 } 259 260 /* 261 * Warning the order of the low / high byte is the other way around 262 * as on most other superio devices!! 263 */ 264 *address = superio_inb(sioaddr, SIO_REG_ADDR) | 265 superio_inb(sioaddr, SIO_REG_ADDR + 1) << 8; 266 if (*address == 0) { 267 pr_warn("Base address not set\n"); 268 err = -ENODEV; 269 goto exit; 270 } 271 272 exit: 273 superio_exit(sioaddr); 274 return err; 275 } 276 277 static int __init sch56xx_device_add(unsigned short address, const char *name) 278 { 279 struct resource res = { 280 .start = address, 281 .end = address + REGION_LENGTH - 1, 282 .flags = IORESOURCE_IO, 283 }; 284 int err; 285 286 sch56xx_pdev = platform_device_alloc(name, address); 287 if (!sch56xx_pdev) 288 return -ENOMEM; 289 290 res.name = sch56xx_pdev->name; 291 err = acpi_check_resource_conflict(&res); 292 if (err) 293 goto exit_device_put; 294 295 err = platform_device_add_resources(sch56xx_pdev, &res, 1); 296 if (err) { 297 pr_err("Device resource addition failed\n"); 298 goto exit_device_put; 299 } 300 301 err = platform_device_add(sch56xx_pdev); 302 if (err) { 303 pr_err("Device addition failed\n"); 304 goto exit_device_put; 305 } 306 307 return 0; 308 309 exit_device_put: 310 platform_device_put(sch56xx_pdev); 311 312 return err; 313 } 314 315 static int __init sch56xx_init(void) 316 { 317 int err; 318 unsigned short address; 319 const char *name; 320 321 err = sch56xx_find(0x4e, &address, &name); 322 if (err) 323 err = sch56xx_find(0x2e, &address, &name); 324 if (err) 325 return err; 326 327 return sch56xx_device_add(address, name); 328 } 329 330 static void __exit sch56xx_exit(void) 331 { 332 platform_device_unregister(sch56xx_pdev); 333 } 334 335 MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code"); 336 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 337 MODULE_LICENSE("GPL"); 338 339 module_init(sch56xx_init); 340 module_exit(sch56xx_exit); 341