1 /* 2 * SPI driver for Micrel/Kendin KS8995M ethernet switch 3 * 4 * Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org> 5 * 6 * This file was based on: drivers/spi/at25.c 7 * Copyright (C) 2006 David Brownell 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License version 2 as published 11 * by the Free Software Foundation. 12 */ 13 14 #include <linux/types.h> 15 #include <linux/kernel.h> 16 #include <linux/init.h> 17 #include <linux/module.h> 18 #include <linux/delay.h> 19 #include <linux/device.h> 20 21 #include <linux/spi/spi.h> 22 23 #define DRV_VERSION "0.1.1" 24 #define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver" 25 26 /* ------------------------------------------------------------------------ */ 27 28 #define KS8995_REG_ID0 0x00 /* Chip ID0 */ 29 #define KS8995_REG_ID1 0x01 /* Chip ID1 */ 30 31 #define KS8995_REG_GC0 0x02 /* Global Control 0 */ 32 #define KS8995_REG_GC1 0x03 /* Global Control 1 */ 33 #define KS8995_REG_GC2 0x04 /* Global Control 2 */ 34 #define KS8995_REG_GC3 0x05 /* Global Control 3 */ 35 #define KS8995_REG_GC4 0x06 /* Global Control 4 */ 36 #define KS8995_REG_GC5 0x07 /* Global Control 5 */ 37 #define KS8995_REG_GC6 0x08 /* Global Control 6 */ 38 #define KS8995_REG_GC7 0x09 /* Global Control 7 */ 39 #define KS8995_REG_GC8 0x0a /* Global Control 8 */ 40 #define KS8995_REG_GC9 0x0b /* Global Control 9 */ 41 42 #define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */ 43 #define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */ 44 45 #define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */ 46 #define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */ 47 #define KS8995_REG_TPC2 0x62 /* TOS Priority Control 2 */ 48 #define KS8995_REG_TPC3 0x63 /* TOS Priority Control 3 */ 49 #define KS8995_REG_TPC4 0x64 /* TOS Priority Control 4 */ 50 #define KS8995_REG_TPC5 0x65 /* TOS Priority Control 5 */ 51 #define KS8995_REG_TPC6 0x66 /* TOS Priority Control 6 */ 52 #define KS8995_REG_TPC7 0x67 /* TOS Priority Control 7 */ 53 54 #define KS8995_REG_MAC0 0x68 /* MAC address 0 */ 55 #define KS8995_REG_MAC1 0x69 /* MAC address 1 */ 56 #define KS8995_REG_MAC2 0x6a /* MAC address 2 */ 57 #define KS8995_REG_MAC3 0x6b /* MAC address 3 */ 58 #define KS8995_REG_MAC4 0x6c /* MAC address 4 */ 59 #define KS8995_REG_MAC5 0x6d /* MAC address 5 */ 60 61 #define KS8995_REG_IAC0 0x6e /* Indirect Access Control 0 */ 62 #define KS8995_REG_IAC1 0x6f /* Indirect Access Control 0 */ 63 #define KS8995_REG_IAD7 0x70 /* Indirect Access Data 7 */ 64 #define KS8995_REG_IAD6 0x71 /* Indirect Access Data 6 */ 65 #define KS8995_REG_IAD5 0x72 /* Indirect Access Data 5 */ 66 #define KS8995_REG_IAD4 0x73 /* Indirect Access Data 4 */ 67 #define KS8995_REG_IAD3 0x74 /* Indirect Access Data 3 */ 68 #define KS8995_REG_IAD2 0x75 /* Indirect Access Data 2 */ 69 #define KS8995_REG_IAD1 0x76 /* Indirect Access Data 1 */ 70 #define KS8995_REG_IAD0 0x77 /* Indirect Access Data 0 */ 71 72 #define KS8995_REGS_SIZE 0x80 73 74 #define ID1_CHIPID_M 0xf 75 #define ID1_CHIPID_S 4 76 #define ID1_REVISION_M 0x7 77 #define ID1_REVISION_S 1 78 #define ID1_START_SW 1 /* start the switch */ 79 80 #define FAMILY_KS8995 0x95 81 #define CHIPID_M 0 82 83 #define KS8995_CMD_WRITE 0x02U 84 #define KS8995_CMD_READ 0x03U 85 86 #define KS8995_RESET_DELAY 10 /* usec */ 87 88 struct ks8995_pdata { 89 /* not yet implemented */ 90 }; 91 92 struct ks8995_switch { 93 struct spi_device *spi; 94 struct mutex lock; 95 struct ks8995_pdata *pdata; 96 }; 97 98 static inline u8 get_chip_id(u8 val) 99 { 100 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M; 101 } 102 103 static inline u8 get_chip_rev(u8 val) 104 { 105 return (val >> ID1_REVISION_S) & ID1_REVISION_M; 106 } 107 108 /* ------------------------------------------------------------------------ */ 109 static int ks8995_read(struct ks8995_switch *ks, char *buf, 110 unsigned offset, size_t count) 111 { 112 u8 cmd[2]; 113 struct spi_transfer t[2]; 114 struct spi_message m; 115 int err; 116 117 spi_message_init(&m); 118 119 memset(&t, 0, sizeof(t)); 120 121 t[0].tx_buf = cmd; 122 t[0].len = sizeof(cmd); 123 spi_message_add_tail(&t[0], &m); 124 125 t[1].rx_buf = buf; 126 t[1].len = count; 127 spi_message_add_tail(&t[1], &m); 128 129 cmd[0] = KS8995_CMD_READ; 130 cmd[1] = offset; 131 132 mutex_lock(&ks->lock); 133 err = spi_sync(ks->spi, &m); 134 mutex_unlock(&ks->lock); 135 136 return err ? err : count; 137 } 138 139 140 static int ks8995_write(struct ks8995_switch *ks, char *buf, 141 unsigned offset, size_t count) 142 { 143 u8 cmd[2]; 144 struct spi_transfer t[2]; 145 struct spi_message m; 146 int err; 147 148 spi_message_init(&m); 149 150 memset(&t, 0, sizeof(t)); 151 152 t[0].tx_buf = cmd; 153 t[0].len = sizeof(cmd); 154 spi_message_add_tail(&t[0], &m); 155 156 t[1].tx_buf = buf; 157 t[1].len = count; 158 spi_message_add_tail(&t[1], &m); 159 160 cmd[0] = KS8995_CMD_WRITE; 161 cmd[1] = offset; 162 163 mutex_lock(&ks->lock); 164 err = spi_sync(ks->spi, &m); 165 mutex_unlock(&ks->lock); 166 167 return err ? err : count; 168 } 169 170 static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf) 171 { 172 return (ks8995_read(ks, buf, addr, 1) != 1); 173 } 174 175 static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val) 176 { 177 char buf = val; 178 179 return (ks8995_write(ks, &buf, addr, 1) != 1); 180 } 181 182 /* ------------------------------------------------------------------------ */ 183 184 static int ks8995_stop(struct ks8995_switch *ks) 185 { 186 return ks8995_write_reg(ks, KS8995_REG_ID1, 0); 187 } 188 189 static int ks8995_start(struct ks8995_switch *ks) 190 { 191 return ks8995_write_reg(ks, KS8995_REG_ID1, 1); 192 } 193 194 static int ks8995_reset(struct ks8995_switch *ks) 195 { 196 int err; 197 198 err = ks8995_stop(ks); 199 if (err) 200 return err; 201 202 udelay(KS8995_RESET_DELAY); 203 204 return ks8995_start(ks); 205 } 206 207 /* ------------------------------------------------------------------------ */ 208 209 static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj, 210 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) 211 { 212 struct device *dev; 213 struct ks8995_switch *ks8995; 214 215 dev = container_of(kobj, struct device, kobj); 216 ks8995 = dev_get_drvdata(dev); 217 218 if (unlikely(off > KS8995_REGS_SIZE)) 219 return 0; 220 221 if ((off + count) > KS8995_REGS_SIZE) 222 count = KS8995_REGS_SIZE - off; 223 224 if (unlikely(!count)) 225 return count; 226 227 return ks8995_read(ks8995, buf, off, count); 228 } 229 230 231 static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj, 232 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) 233 { 234 struct device *dev; 235 struct ks8995_switch *ks8995; 236 237 dev = container_of(kobj, struct device, kobj); 238 ks8995 = dev_get_drvdata(dev); 239 240 if (unlikely(off >= KS8995_REGS_SIZE)) 241 return -EFBIG; 242 243 if ((off + count) > KS8995_REGS_SIZE) 244 count = KS8995_REGS_SIZE - off; 245 246 if (unlikely(!count)) 247 return count; 248 249 return ks8995_write(ks8995, buf, off, count); 250 } 251 252 253 static struct bin_attribute ks8995_registers_attr = { 254 .attr = { 255 .name = "registers", 256 .mode = S_IRUSR | S_IWUSR, 257 }, 258 .size = KS8995_REGS_SIZE, 259 .read = ks8995_registers_read, 260 .write = ks8995_registers_write, 261 }; 262 263 /* ------------------------------------------------------------------------ */ 264 265 static int __devinit ks8995_probe(struct spi_device *spi) 266 { 267 struct ks8995_switch *ks; 268 struct ks8995_pdata *pdata; 269 u8 ids[2]; 270 int err; 271 272 /* Chip description */ 273 pdata = spi->dev.platform_data; 274 275 ks = kzalloc(sizeof(*ks), GFP_KERNEL); 276 if (!ks) { 277 dev_err(&spi->dev, "no memory for private data\n"); 278 return -ENOMEM; 279 } 280 281 mutex_init(&ks->lock); 282 ks->pdata = pdata; 283 ks->spi = spi_dev_get(spi); 284 dev_set_drvdata(&spi->dev, ks); 285 286 spi->mode = SPI_MODE_0; 287 spi->bits_per_word = 8; 288 err = spi_setup(spi); 289 if (err) { 290 dev_err(&spi->dev, "spi_setup failed, err=%d\n", err); 291 goto err_drvdata; 292 } 293 294 err = ks8995_read(ks, ids, KS8995_REG_ID0, sizeof(ids)); 295 if (err < 0) { 296 dev_err(&spi->dev, "unable to read id registers, err=%d\n", 297 err); 298 goto err_drvdata; 299 } 300 301 switch (ids[0]) { 302 case FAMILY_KS8995: 303 break; 304 default: 305 dev_err(&spi->dev, "unknown family id:%02x\n", ids[0]); 306 err = -ENODEV; 307 goto err_drvdata; 308 } 309 310 err = ks8995_reset(ks); 311 if (err) 312 goto err_drvdata; 313 314 err = sysfs_create_bin_file(&spi->dev.kobj, &ks8995_registers_attr); 315 if (err) { 316 dev_err(&spi->dev, "unable to create sysfs file, err=%d\n", 317 err); 318 goto err_drvdata; 319 } 320 321 dev_info(&spi->dev, "KS89%02X device found, Chip ID:%01x, " 322 "Revision:%01x\n", ids[0], 323 get_chip_id(ids[1]), get_chip_rev(ids[1])); 324 325 return 0; 326 327 err_drvdata: 328 dev_set_drvdata(&spi->dev, NULL); 329 kfree(ks); 330 return err; 331 } 332 333 static int __devexit ks8995_remove(struct spi_device *spi) 334 { 335 struct ks8995_data *ks8995; 336 337 ks8995 = dev_get_drvdata(&spi->dev); 338 sysfs_remove_bin_file(&spi->dev.kobj, &ks8995_registers_attr); 339 340 dev_set_drvdata(&spi->dev, NULL); 341 kfree(ks8995); 342 343 return 0; 344 } 345 346 /* ------------------------------------------------------------------------ */ 347 348 static struct spi_driver ks8995_driver = { 349 .driver = { 350 .name = "spi-ks8995", 351 .bus = &spi_bus_type, 352 .owner = THIS_MODULE, 353 }, 354 .probe = ks8995_probe, 355 .remove = __devexit_p(ks8995_remove), 356 }; 357 358 static int __init ks8995_init(void) 359 { 360 printk(KERN_INFO DRV_DESC " version " DRV_VERSION"\n"); 361 362 return spi_register_driver(&ks8995_driver); 363 } 364 module_init(ks8995_init); 365 366 static void __exit ks8995_exit(void) 367 { 368 spi_unregister_driver(&ks8995_driver); 369 } 370 module_exit(ks8995_exit); 371 372 MODULE_DESCRIPTION(DRV_DESC); 373 MODULE_VERSION(DRV_VERSION); 374 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>"); 375 MODULE_LICENSE("GPL v2"); 376