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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 15 16 #include <linux/types.h> 17 #include <linux/kernel.h> 18 #include <linux/init.h> 19 #include <linux/module.h> 20 #include <linux/delay.h> 21 #include <linux/device.h> 22 23 #include <linux/spi/spi.h> 24 25 #define DRV_VERSION "0.1.1" 26 #define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver" 27 28 /* ------------------------------------------------------------------------ */ 29 30 #define KS8995_REG_ID0 0x00 /* Chip ID0 */ 31 #define KS8995_REG_ID1 0x01 /* Chip ID1 */ 32 33 #define KS8995_REG_GC0 0x02 /* Global Control 0 */ 34 #define KS8995_REG_GC1 0x03 /* Global Control 1 */ 35 #define KS8995_REG_GC2 0x04 /* Global Control 2 */ 36 #define KS8995_REG_GC3 0x05 /* Global Control 3 */ 37 #define KS8995_REG_GC4 0x06 /* Global Control 4 */ 38 #define KS8995_REG_GC5 0x07 /* Global Control 5 */ 39 #define KS8995_REG_GC6 0x08 /* Global Control 6 */ 40 #define KS8995_REG_GC7 0x09 /* Global Control 7 */ 41 #define KS8995_REG_GC8 0x0a /* Global Control 8 */ 42 #define KS8995_REG_GC9 0x0b /* Global Control 9 */ 43 44 #define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */ 45 #define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */ 46 47 #define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */ 48 #define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */ 49 #define KS8995_REG_TPC2 0x62 /* TOS Priority Control 2 */ 50 #define KS8995_REG_TPC3 0x63 /* TOS Priority Control 3 */ 51 #define KS8995_REG_TPC4 0x64 /* TOS Priority Control 4 */ 52 #define KS8995_REG_TPC5 0x65 /* TOS Priority Control 5 */ 53 #define KS8995_REG_TPC6 0x66 /* TOS Priority Control 6 */ 54 #define KS8995_REG_TPC7 0x67 /* TOS Priority Control 7 */ 55 56 #define KS8995_REG_MAC0 0x68 /* MAC address 0 */ 57 #define KS8995_REG_MAC1 0x69 /* MAC address 1 */ 58 #define KS8995_REG_MAC2 0x6a /* MAC address 2 */ 59 #define KS8995_REG_MAC3 0x6b /* MAC address 3 */ 60 #define KS8995_REG_MAC4 0x6c /* MAC address 4 */ 61 #define KS8995_REG_MAC5 0x6d /* MAC address 5 */ 62 63 #define KS8995_REG_IAC0 0x6e /* Indirect Access Control 0 */ 64 #define KS8995_REG_IAC1 0x6f /* Indirect Access Control 0 */ 65 #define KS8995_REG_IAD7 0x70 /* Indirect Access Data 7 */ 66 #define KS8995_REG_IAD6 0x71 /* Indirect Access Data 6 */ 67 #define KS8995_REG_IAD5 0x72 /* Indirect Access Data 5 */ 68 #define KS8995_REG_IAD4 0x73 /* Indirect Access Data 4 */ 69 #define KS8995_REG_IAD3 0x74 /* Indirect Access Data 3 */ 70 #define KS8995_REG_IAD2 0x75 /* Indirect Access Data 2 */ 71 #define KS8995_REG_IAD1 0x76 /* Indirect Access Data 1 */ 72 #define KS8995_REG_IAD0 0x77 /* Indirect Access Data 0 */ 73 74 #define KS8995_REGS_SIZE 0x80 75 76 #define ID1_CHIPID_M 0xf 77 #define ID1_CHIPID_S 4 78 #define ID1_REVISION_M 0x7 79 #define ID1_REVISION_S 1 80 #define ID1_START_SW 1 /* start the switch */ 81 82 #define FAMILY_KS8995 0x95 83 #define CHIPID_M 0 84 85 #define KS8995_CMD_WRITE 0x02U 86 #define KS8995_CMD_READ 0x03U 87 88 #define KS8995_RESET_DELAY 10 /* usec */ 89 90 struct ks8995_pdata { 91 /* not yet implemented */ 92 }; 93 94 struct ks8995_switch { 95 struct spi_device *spi; 96 struct mutex lock; 97 struct ks8995_pdata *pdata; 98 }; 99 100 static inline u8 get_chip_id(u8 val) 101 { 102 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M; 103 } 104 105 static inline u8 get_chip_rev(u8 val) 106 { 107 return (val >> ID1_REVISION_S) & ID1_REVISION_M; 108 } 109 110 /* ------------------------------------------------------------------------ */ 111 static int ks8995_read(struct ks8995_switch *ks, char *buf, 112 unsigned offset, size_t count) 113 { 114 u8 cmd[2]; 115 struct spi_transfer t[2]; 116 struct spi_message m; 117 int err; 118 119 spi_message_init(&m); 120 121 memset(&t, 0, sizeof(t)); 122 123 t[0].tx_buf = cmd; 124 t[0].len = sizeof(cmd); 125 spi_message_add_tail(&t[0], &m); 126 127 t[1].rx_buf = buf; 128 t[1].len = count; 129 spi_message_add_tail(&t[1], &m); 130 131 cmd[0] = KS8995_CMD_READ; 132 cmd[1] = offset; 133 134 mutex_lock(&ks->lock); 135 err = spi_sync(ks->spi, &m); 136 mutex_unlock(&ks->lock); 137 138 return err ? err : count; 139 } 140 141 142 static int ks8995_write(struct ks8995_switch *ks, char *buf, 143 unsigned offset, size_t count) 144 { 145 u8 cmd[2]; 146 struct spi_transfer t[2]; 147 struct spi_message m; 148 int err; 149 150 spi_message_init(&m); 151 152 memset(&t, 0, sizeof(t)); 153 154 t[0].tx_buf = cmd; 155 t[0].len = sizeof(cmd); 156 spi_message_add_tail(&t[0], &m); 157 158 t[1].tx_buf = buf; 159 t[1].len = count; 160 spi_message_add_tail(&t[1], &m); 161 162 cmd[0] = KS8995_CMD_WRITE; 163 cmd[1] = offset; 164 165 mutex_lock(&ks->lock); 166 err = spi_sync(ks->spi, &m); 167 mutex_unlock(&ks->lock); 168 169 return err ? err : count; 170 } 171 172 static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf) 173 { 174 return (ks8995_read(ks, buf, addr, 1) != 1); 175 } 176 177 static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val) 178 { 179 char buf = val; 180 181 return (ks8995_write(ks, &buf, addr, 1) != 1); 182 } 183 184 /* ------------------------------------------------------------------------ */ 185 186 static int ks8995_stop(struct ks8995_switch *ks) 187 { 188 return ks8995_write_reg(ks, KS8995_REG_ID1, 0); 189 } 190 191 static int ks8995_start(struct ks8995_switch *ks) 192 { 193 return ks8995_write_reg(ks, KS8995_REG_ID1, 1); 194 } 195 196 static int ks8995_reset(struct ks8995_switch *ks) 197 { 198 int err; 199 200 err = ks8995_stop(ks); 201 if (err) 202 return err; 203 204 udelay(KS8995_RESET_DELAY); 205 206 return ks8995_start(ks); 207 } 208 209 /* ------------------------------------------------------------------------ */ 210 211 static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj, 212 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) 213 { 214 struct device *dev; 215 struct ks8995_switch *ks8995; 216 217 dev = container_of(kobj, struct device, kobj); 218 ks8995 = dev_get_drvdata(dev); 219 220 if (unlikely(off > KS8995_REGS_SIZE)) 221 return 0; 222 223 if ((off + count) > KS8995_REGS_SIZE) 224 count = KS8995_REGS_SIZE - off; 225 226 if (unlikely(!count)) 227 return count; 228 229 return ks8995_read(ks8995, buf, off, count); 230 } 231 232 233 static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj, 234 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) 235 { 236 struct device *dev; 237 struct ks8995_switch *ks8995; 238 239 dev = container_of(kobj, struct device, kobj); 240 ks8995 = dev_get_drvdata(dev); 241 242 if (unlikely(off >= KS8995_REGS_SIZE)) 243 return -EFBIG; 244 245 if ((off + count) > KS8995_REGS_SIZE) 246 count = KS8995_REGS_SIZE - off; 247 248 if (unlikely(!count)) 249 return count; 250 251 return ks8995_write(ks8995, buf, off, count); 252 } 253 254 255 static struct bin_attribute ks8995_registers_attr = { 256 .attr = { 257 .name = "registers", 258 .mode = S_IRUSR | S_IWUSR, 259 }, 260 .size = KS8995_REGS_SIZE, 261 .read = ks8995_registers_read, 262 .write = ks8995_registers_write, 263 }; 264 265 /* ------------------------------------------------------------------------ */ 266 267 static int ks8995_probe(struct spi_device *spi) 268 { 269 struct ks8995_switch *ks; 270 struct ks8995_pdata *pdata; 271 u8 ids[2]; 272 int err; 273 274 /* Chip description */ 275 pdata = spi->dev.platform_data; 276 277 ks = kzalloc(sizeof(*ks), GFP_KERNEL); 278 if (!ks) 279 return -ENOMEM; 280 281 mutex_init(&ks->lock); 282 ks->pdata = pdata; 283 ks->spi = spi_dev_get(spi); 284 spi_set_drvdata(spi, 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 kfree(ks); 329 return err; 330 } 331 332 static int ks8995_remove(struct spi_device *spi) 333 { 334 struct ks8995_data *ks8995; 335 336 ks8995 = spi_get_drvdata(spi); 337 sysfs_remove_bin_file(&spi->dev.kobj, &ks8995_registers_attr); 338 339 kfree(ks8995); 340 341 return 0; 342 } 343 344 /* ------------------------------------------------------------------------ */ 345 346 static struct spi_driver ks8995_driver = { 347 .driver = { 348 .name = "spi-ks8995", 349 .owner = THIS_MODULE, 350 }, 351 .probe = ks8995_probe, 352 .remove = ks8995_remove, 353 }; 354 355 module_spi_driver(ks8995_driver); 356 357 MODULE_DESCRIPTION(DRV_DESC); 358 MODULE_VERSION(DRV_VERSION); 359 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>"); 360 MODULE_LICENSE("GPL v2"); 361