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/module.h> 19 #include <linux/delay.h> 20 #include <linux/device.h> 21 22 #include <linux/spi/spi.h> 23 24 #define DRV_VERSION "0.1.1" 25 #define DRV_DESC "Micrel KS8995 Ethernet switch SPI driver" 26 27 /* ------------------------------------------------------------------------ */ 28 29 #define KS8995_REG_ID0 0x00 /* Chip ID0 */ 30 #define KS8995_REG_ID1 0x01 /* Chip ID1 */ 31 32 #define KS8995_REG_GC0 0x02 /* Global Control 0 */ 33 #define KS8995_REG_GC1 0x03 /* Global Control 1 */ 34 #define KS8995_REG_GC2 0x04 /* Global Control 2 */ 35 #define KS8995_REG_GC3 0x05 /* Global Control 3 */ 36 #define KS8995_REG_GC4 0x06 /* Global Control 4 */ 37 #define KS8995_REG_GC5 0x07 /* Global Control 5 */ 38 #define KS8995_REG_GC6 0x08 /* Global Control 6 */ 39 #define KS8995_REG_GC7 0x09 /* Global Control 7 */ 40 #define KS8995_REG_GC8 0x0a /* Global Control 8 */ 41 #define KS8995_REG_GC9 0x0b /* Global Control 9 */ 42 43 #define KS8995_REG_PC(p, r) ((0x10 * p) + r) /* Port Control */ 44 #define KS8995_REG_PS(p, r) ((0x10 * p) + r + 0xe) /* Port Status */ 45 46 #define KS8995_REG_TPC0 0x60 /* TOS Priority Control 0 */ 47 #define KS8995_REG_TPC1 0x61 /* TOS Priority Control 1 */ 48 #define KS8995_REG_TPC2 0x62 /* TOS Priority Control 2 */ 49 #define KS8995_REG_TPC3 0x63 /* TOS Priority Control 3 */ 50 #define KS8995_REG_TPC4 0x64 /* TOS Priority Control 4 */ 51 #define KS8995_REG_TPC5 0x65 /* TOS Priority Control 5 */ 52 #define KS8995_REG_TPC6 0x66 /* TOS Priority Control 6 */ 53 #define KS8995_REG_TPC7 0x67 /* TOS Priority Control 7 */ 54 55 #define KS8995_REG_MAC0 0x68 /* MAC address 0 */ 56 #define KS8995_REG_MAC1 0x69 /* MAC address 1 */ 57 #define KS8995_REG_MAC2 0x6a /* MAC address 2 */ 58 #define KS8995_REG_MAC3 0x6b /* MAC address 3 */ 59 #define KS8995_REG_MAC4 0x6c /* MAC address 4 */ 60 #define KS8995_REG_MAC5 0x6d /* MAC address 5 */ 61 62 #define KS8995_REG_IAC0 0x6e /* Indirect Access Control 0 */ 63 #define KS8995_REG_IAC1 0x6f /* Indirect Access Control 0 */ 64 #define KS8995_REG_IAD7 0x70 /* Indirect Access Data 7 */ 65 #define KS8995_REG_IAD6 0x71 /* Indirect Access Data 6 */ 66 #define KS8995_REG_IAD5 0x72 /* Indirect Access Data 5 */ 67 #define KS8995_REG_IAD4 0x73 /* Indirect Access Data 4 */ 68 #define KS8995_REG_IAD3 0x74 /* Indirect Access Data 3 */ 69 #define KS8995_REG_IAD2 0x75 /* Indirect Access Data 2 */ 70 #define KS8995_REG_IAD1 0x76 /* Indirect Access Data 1 */ 71 #define KS8995_REG_IAD0 0x77 /* Indirect Access Data 0 */ 72 73 #define KS8995_REGS_SIZE 0x80 74 75 #define ID1_CHIPID_M 0xf 76 #define ID1_CHIPID_S 4 77 #define ID1_REVISION_M 0x7 78 #define ID1_REVISION_S 1 79 #define ID1_START_SW 1 /* start the switch */ 80 81 #define FAMILY_KS8995 0x95 82 #define CHIPID_M 0 83 84 #define KS8995_CMD_WRITE 0x02U 85 #define KS8995_CMD_READ 0x03U 86 87 #define KS8995_RESET_DELAY 10 /* usec */ 88 89 struct ks8995_pdata { 90 /* not yet implemented */ 91 }; 92 93 struct ks8995_switch { 94 struct spi_device *spi; 95 struct mutex lock; 96 struct ks8995_pdata *pdata; 97 }; 98 99 static inline u8 get_chip_id(u8 val) 100 { 101 return (val >> ID1_CHIPID_S) & ID1_CHIPID_M; 102 } 103 104 static inline u8 get_chip_rev(u8 val) 105 { 106 return (val >> ID1_REVISION_S) & ID1_REVISION_M; 107 } 108 109 /* ------------------------------------------------------------------------ */ 110 static int ks8995_read(struct ks8995_switch *ks, char *buf, 111 unsigned offset, size_t count) 112 { 113 u8 cmd[2]; 114 struct spi_transfer t[2]; 115 struct spi_message m; 116 int err; 117 118 spi_message_init(&m); 119 120 memset(&t, 0, sizeof(t)); 121 122 t[0].tx_buf = cmd; 123 t[0].len = sizeof(cmd); 124 spi_message_add_tail(&t[0], &m); 125 126 t[1].rx_buf = buf; 127 t[1].len = count; 128 spi_message_add_tail(&t[1], &m); 129 130 cmd[0] = KS8995_CMD_READ; 131 cmd[1] = offset; 132 133 mutex_lock(&ks->lock); 134 err = spi_sync(ks->spi, &m); 135 mutex_unlock(&ks->lock); 136 137 return err ? err : count; 138 } 139 140 141 static int ks8995_write(struct ks8995_switch *ks, char *buf, 142 unsigned offset, size_t count) 143 { 144 u8 cmd[2]; 145 struct spi_transfer t[2]; 146 struct spi_message m; 147 int err; 148 149 spi_message_init(&m); 150 151 memset(&t, 0, sizeof(t)); 152 153 t[0].tx_buf = cmd; 154 t[0].len = sizeof(cmd); 155 spi_message_add_tail(&t[0], &m); 156 157 t[1].tx_buf = buf; 158 t[1].len = count; 159 spi_message_add_tail(&t[1], &m); 160 161 cmd[0] = KS8995_CMD_WRITE; 162 cmd[1] = offset; 163 164 mutex_lock(&ks->lock); 165 err = spi_sync(ks->spi, &m); 166 mutex_unlock(&ks->lock); 167 168 return err ? err : count; 169 } 170 171 static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf) 172 { 173 return ks8995_read(ks, buf, addr, 1) != 1; 174 } 175 176 static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val) 177 { 178 char buf = val; 179 180 return ks8995_write(ks, &buf, addr, 1) != 1; 181 } 182 183 /* ------------------------------------------------------------------------ */ 184 185 static int ks8995_stop(struct ks8995_switch *ks) 186 { 187 return ks8995_write_reg(ks, KS8995_REG_ID1, 0); 188 } 189 190 static int ks8995_start(struct ks8995_switch *ks) 191 { 192 return ks8995_write_reg(ks, KS8995_REG_ID1, 1); 193 } 194 195 static int ks8995_reset(struct ks8995_switch *ks) 196 { 197 int err; 198 199 err = ks8995_stop(ks); 200 if (err) 201 return err; 202 203 udelay(KS8995_RESET_DELAY); 204 205 return ks8995_start(ks); 206 } 207 208 /* ------------------------------------------------------------------------ */ 209 210 static ssize_t ks8995_registers_read(struct file *filp, struct kobject *kobj, 211 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) 212 { 213 struct device *dev; 214 struct ks8995_switch *ks8995; 215 216 dev = container_of(kobj, struct device, kobj); 217 ks8995 = dev_get_drvdata(dev); 218 219 if (unlikely(off > KS8995_REGS_SIZE)) 220 return 0; 221 222 if ((off + count) > KS8995_REGS_SIZE) 223 count = KS8995_REGS_SIZE - off; 224 225 if (unlikely(!count)) 226 return count; 227 228 return ks8995_read(ks8995, buf, off, count); 229 } 230 231 232 static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj, 233 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) 234 { 235 struct device *dev; 236 struct ks8995_switch *ks8995; 237 238 dev = container_of(kobj, struct device, kobj); 239 ks8995 = dev_get_drvdata(dev); 240 241 if (unlikely(off >= KS8995_REGS_SIZE)) 242 return -EFBIG; 243 244 if ((off + count) > KS8995_REGS_SIZE) 245 count = KS8995_REGS_SIZE - off; 246 247 if (unlikely(!count)) 248 return count; 249 250 return ks8995_write(ks8995, buf, off, count); 251 } 252 253 254 static struct bin_attribute ks8995_registers_attr = { 255 .attr = { 256 .name = "registers", 257 .mode = S_IRUSR | S_IWUSR, 258 }, 259 .size = KS8995_REGS_SIZE, 260 .read = ks8995_registers_read, 261 .write = ks8995_registers_write, 262 }; 263 264 /* ------------------------------------------------------------------------ */ 265 266 static int ks8995_probe(struct spi_device *spi) 267 { 268 struct ks8995_switch *ks; 269 struct ks8995_pdata *pdata; 270 u8 ids[2]; 271 int err; 272 273 /* Chip description */ 274 pdata = spi->dev.platform_data; 275 276 ks = kzalloc(sizeof(*ks), GFP_KERNEL); 277 if (!ks) 278 return -ENOMEM; 279 280 mutex_init(&ks->lock); 281 ks->pdata = pdata; 282 ks->spi = spi_dev_get(spi); 283 spi_set_drvdata(spi, ks); 284 285 spi->mode = SPI_MODE_0; 286 spi->bits_per_word = 8; 287 err = spi_setup(spi); 288 if (err) { 289 dev_err(&spi->dev, "spi_setup failed, err=%d\n", err); 290 goto err_drvdata; 291 } 292 293 err = ks8995_read(ks, ids, KS8995_REG_ID0, sizeof(ids)); 294 if (err < 0) { 295 dev_err(&spi->dev, "unable to read id registers, err=%d\n", 296 err); 297 goto err_drvdata; 298 } 299 300 switch (ids[0]) { 301 case FAMILY_KS8995: 302 break; 303 default: 304 dev_err(&spi->dev, "unknown family id:%02x\n", ids[0]); 305 err = -ENODEV; 306 goto err_drvdata; 307 } 308 309 err = ks8995_reset(ks); 310 if (err) 311 goto err_drvdata; 312 313 err = sysfs_create_bin_file(&spi->dev.kobj, &ks8995_registers_attr); 314 if (err) { 315 dev_err(&spi->dev, "unable to create sysfs file, err=%d\n", 316 err); 317 goto err_drvdata; 318 } 319 320 dev_info(&spi->dev, "KS89%02X device found, Chip ID:%01x, " 321 "Revision:%01x\n", ids[0], 322 get_chip_id(ids[1]), get_chip_rev(ids[1])); 323 324 return 0; 325 326 err_drvdata: 327 kfree(ks); 328 return err; 329 } 330 331 static int ks8995_remove(struct spi_device *spi) 332 { 333 struct ks8995_data *ks8995; 334 335 ks8995 = spi_get_drvdata(spi); 336 sysfs_remove_bin_file(&spi->dev.kobj, &ks8995_registers_attr); 337 338 kfree(ks8995); 339 340 return 0; 341 } 342 343 /* ------------------------------------------------------------------------ */ 344 345 static struct spi_driver ks8995_driver = { 346 .driver = { 347 .name = "spi-ks8995", 348 .owner = THIS_MODULE, 349 }, 350 .probe = ks8995_probe, 351 .remove = ks8995_remove, 352 }; 353 354 module_spi_driver(ks8995_driver); 355 356 MODULE_DESCRIPTION(DRV_DESC); 357 MODULE_VERSION(DRV_VERSION); 358 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>"); 359 MODULE_LICENSE("GPL v2"); 360