drivers/spi/tle62x0.c

   1 /*
   2  * tle62x0.c -- support Infineon TLE62x0 driver chips
   3  *
   4  * Copyright (c) 2007 Simtec Electronics
   5  *      Ben Dooks, <ben@simtec.co.uk>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/device.h>
  13 #include <linux/kernel.h>
  14
  15 #include <linux/spi/spi.h>
  16 #include <linux/spi/tle62x0.h>
  17
  18
  19 #define CMD_READ        0x00
  20 #define CMD_SET         0xff
  21
  22 #define DIAG_NORMAL     0x03
  23 #define DIAG_OVERLOAD   0x02
  24 #define DIAG_OPEN       0x01
  25 #define DIAG_SHORTGND   0x00
  26
  27 struct tle62x0_state {
  28         struct spi_device       *us;
  29         struct mutex            lock;
  30         unsigned int            nr_gpio;
  31         unsigned int            gpio_state;
  32
  33         unsigned char           tx_buff[4];
  34         unsigned char           rx_buff[4];
  35 };
  36
  37 static int to_gpio_num(struct device_attribute *attr);
  38
  39 static inline int tle62x0_write(struct tle62x0_state *st)
  40 {
  41         unsigned char *buff = st->tx_buff;
  42         unsigned int gpio_state = st->gpio_state;
  43
  44         buff[0] = CMD_SET;
  45
  46         if (st->nr_gpio == 16) {
  47                 buff[1] = gpio_state >> 8;
  48                 buff[2] = gpio_state;
  49         } else {
  50                 buff[1] = gpio_state;
  51         }
  52
  53         dev_dbg(&st->us->dev, "buff %02x,%02x,%02x\n",
  54                 buff[0], buff[1], buff[2]);
  55
  56         return spi_write(st->us, buff, (st->nr_gpio == 16) ? 3 : 2);
  57 }
  58
  59 static inline int tle62x0_read(struct tle62x0_state *st)
  60 {
  61         unsigned char *txbuff = st->tx_buff;
  62         struct spi_transfer xfer = {
  63                 .tx_buf         = txbuff,
  64                 .rx_buf         = st->rx_buff,
  65                 .len            = (st->nr_gpio * 2) / 8,
  66         };
  67         struct spi_message msg;
  68
  69         txbuff[0] = CMD_READ;
  70         txbuff[1] = 0x00;
  71         txbuff[2] = 0x00;
  72         txbuff[3] = 0x00;
  73
  74         spi_message_init(&msg);
  75         spi_message_add_tail(&xfer, &msg);
  76
  77         return spi_sync(st->us, &msg);
  78 }
  79
  80 static unsigned char *decode_fault(unsigned int fault_code)
  81 {
  82         fault_code &= 3;
  83
  84         switch (fault_code) {
  85         case DIAG_NORMAL:
  86                 return "N";
  87         case DIAG_OVERLOAD:
  88                 return "V";
  89         case DIAG_OPEN:
  90                 return "O";
  91         case DIAG_SHORTGND:
  92                 return "G";
  93         }
  94
  95         return "?";
  96 }
  97
  98 static ssize_t tle62x0_status_show(struct device *dev,
  99                 struct device_attribute *attr, char *buf)
 100 {
 101         struct tle62x0_state *st = dev_get_drvdata(dev);
 102         char *bp = buf;
 103         unsigned char *buff = st->rx_buff;
 104         unsigned long fault = 0;
 105         int ptr;
 106         int ret;
 107
 108         mutex_lock(&st->lock);
 109         ret = tle62x0_read(st);
 110         dev_dbg(dev, "tle62x0_read() returned %d\n", ret);
 111         if (ret < 0) {
 112                 mutex_unlock(&st->lock);
 113                 return ret;
 114         }
 115
 116         for (ptr = 0; ptr < (st->nr_gpio * 2)/8; ptr += 1) {
 117                 fault <<= 8;
 118                 fault  |= ((unsigned long)buff[ptr]);
 119
 120                 dev_dbg(dev, "byte %d is %02x\n", ptr, buff[ptr]);
 121         }
 122
 123         for (ptr = 0; ptr < st->nr_gpio; ptr++) {
 124                 bp += sprintf(bp, "%s ", decode_fault(fault >> (ptr * 2)));
 125         }
 126
 127         *bp++ = '\n';
 128
 129         mutex_unlock(&st->lock);
 130         return bp - buf;
 131 }
 132
 133 static DEVICE_ATTR(status_show, S_IRUGO, tle62x0_status_show, NULL);
 134
 135 static ssize_t tle62x0_gpio_show(struct device *dev,
 136                 struct device_attribute *attr, char *buf)
 137 {
 138         struct tle62x0_state *st = dev_get_drvdata(dev);
 139         int gpio_num = to_gpio_num(attr);
 140         int value;
 141
 142         mutex_lock(&st->lock);
 143         value = (st->gpio_state >> gpio_num) & 1;
 144         mutex_unlock(&st->lock);
 145
 146         return snprintf(buf, PAGE_SIZE, "%d", value);
 147 }
 148
 149 static ssize_t tle62x0_gpio_store(struct device *dev,
 150                 struct device_attribute *attr,
 151                 const char *buf, size_t len)
 152 {
 153         struct tle62x0_state *st = dev_get_drvdata(dev);
 154         int gpio_num = to_gpio_num(attr);
 155         unsigned long val;
 156         char *endp;
 157
 158         val = simple_strtoul(buf, &endp, 0);
 159         if (buf == endp)
 160                 return -EINVAL;
 161
 162         dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);
 163
 164         mutex_lock(&st->lock);
 165
 166         if (val)
 167                 st->gpio_state |= 1 << gpio_num;
 168         else
 169                 st->gpio_state &= ~(1 << gpio_num);
 170
 171         tle62x0_write(st);
 172         mutex_unlock(&st->lock);
 173
 174         return len;
 175 }
 176
 177 static DEVICE_ATTR(gpio1, S_IWUSR|S_IRUGO,
 178                 tle62x0_gpio_show, tle62x0_gpio_store);
 179 static DEVICE_ATTR(gpio2, S_IWUSR|S_IRUGO,
 180                 tle62x0_gpio_show, tle62x0_gpio_store);
 181 static DEVICE_ATTR(gpio3, S_IWUSR|S_IRUGO,
 182                 tle62x0_gpio_show, tle62x0_gpio_store);
 183 static DEVICE_ATTR(gpio4, S_IWUSR|S_IRUGO,
 184                 tle62x0_gpio_show, tle62x0_gpio_store);
 185 static DEVICE_ATTR(gpio5, S_IWUSR|S_IRUGO,
 186                 tle62x0_gpio_show, tle62x0_gpio_store);
 187 static DEVICE_ATTR(gpio6, S_IWUSR|S_IRUGO,
 188                 tle62x0_gpio_show, tle62x0_gpio_store);
 189 static DEVICE_ATTR(gpio7, S_IWUSR|S_IRUGO,
 190                 tle62x0_gpio_show, tle62x0_gpio_store);
 191 static DEVICE_ATTR(gpio8, S_IWUSR|S_IRUGO,
 192                 tle62x0_gpio_show, tle62x0_gpio_store);
 193 static DEVICE_ATTR(gpio9, S_IWUSR|S_IRUGO,
 194                 tle62x0_gpio_show, tle62x0_gpio_store);
 195 static DEVICE_ATTR(gpio10, S_IWUSR|S_IRUGO,
 196                 tle62x0_gpio_show, tle62x0_gpio_store);
 197 static DEVICE_ATTR(gpio11, S_IWUSR|S_IRUGO,
 198                 tle62x0_gpio_show, tle62x0_gpio_store);
 199 static DEVICE_ATTR(gpio12, S_IWUSR|S_IRUGO,
 200                 tle62x0_gpio_show, tle62x0_gpio_store);
 201 static DEVICE_ATTR(gpio13, S_IWUSR|S_IRUGO,
 202                 tle62x0_gpio_show, tle62x0_gpio_store);
 203 static DEVICE_ATTR(gpio14, S_IWUSR|S_IRUGO,
 204                 tle62x0_gpio_show, tle62x0_gpio_store);
 205 static DEVICE_ATTR(gpio15, S_IWUSR|S_IRUGO,
 206                 tle62x0_gpio_show, tle62x0_gpio_store);
 207 static DEVICE_ATTR(gpio16, S_IWUSR|S_IRUGO,
 208                 tle62x0_gpio_show, tle62x0_gpio_store);
 209
 210 static struct device_attribute *gpio_attrs[] = {
 211         [0]             = &dev_attr_gpio1,
 212         [1]             = &dev_attr_gpio2,
 213         [2]             = &dev_attr_gpio3,
 214         [3]             = &dev_attr_gpio4,
 215         [4]             = &dev_attr_gpio5,
 216         [5]             = &dev_attr_gpio6,
 217         [6]             = &dev_attr_gpio7,
 218         [7]             = &dev_attr_gpio8,
 219         [8]             = &dev_attr_gpio9,
 220         [9]             = &dev_attr_gpio10,
 221         [10]            = &dev_attr_gpio11,
 222         [11]            = &dev_attr_gpio12,
 223         [12]            = &dev_attr_gpio13,
 224         [13]            = &dev_attr_gpio14,
 225         [14]            = &dev_attr_gpio15,
 226         [15]            = &dev_attr_gpio16
 227 };
 228
 229 static int to_gpio_num(struct device_attribute *attr)
 230 {
 231         int ptr;
 232
 233         for (ptr = 0; ptr < ARRAY_SIZE(gpio_attrs); ptr++) {
 234                 if (gpio_attrs[ptr] == attr)
 235                         return ptr;
 236         }
 237
 238         return -1;
 239 }
 240
 241 static int __devinit tle62x0_probe(struct spi_device *spi)
 242 {
 243         struct tle62x0_state *st;
 244         struct tle62x0_pdata *pdata;
 245         int ptr;
 246         int ret;
 247
 248         pdata = spi->dev.platform_data;
 249         if (pdata == NULL) {
 250                 dev_err(&spi->dev, "no device data specified\n");
 251                 return -EINVAL;
 252         }
 253
 254         st = kzalloc(sizeof(struct tle62x0_state), GFP_KERNEL);
 255         if (st == NULL) {
 256                 dev_err(&spi->dev, "no memory for device state\n");
 257                 return -ENOMEM;
 258         }
 259
 260         st->us = spi;
 261         st->nr_gpio = pdata->gpio_count;
 262         st->gpio_state = pdata->init_state;
 263
 264         mutex_init(&st->lock);
 265
 266         ret = device_create_file(&spi->dev, &dev_attr_status_show);
 267         if (ret) {
 268                 dev_err(&spi->dev, "cannot create status attribute\n");
 269                 goto err_status;
 270         }
 271
 272         for (ptr = 0; ptr < pdata->gpio_count; ptr++) {
 273                 ret = device_create_file(&spi->dev, gpio_attrs[ptr]);
 274                 if (ret) {
 275                         dev_err(&spi->dev, "cannot create gpio attribute\n");
 276                         goto err_gpios;
 277                 }
 278         }
 279
 280         /* tle62x0_write(st); */
 281         spi_set_drvdata(spi, st);
 282         return 0;
 283
 284  err_gpios:
 285         for (; ptr > 0; ptr--)
 286                 device_remove_file(&spi->dev, gpio_attrs[ptr]);
 287
 288         device_remove_file(&spi->dev, &dev_attr_status_show);
 289
 290  err_status:
 291         kfree(st);
 292         return ret;
 293 }
 294
 295 static int __devexit tle62x0_remove(struct spi_device *spi)
 296 {
 297         struct tle62x0_state *st = spi_get_drvdata(spi);
 298         int ptr;
 299
 300         for (ptr = 0; ptr < st->nr_gpio; ptr++)
 301                 device_remove_file(&spi->dev, gpio_attrs[ptr]);
 302
 303         kfree(st);
 304         return 0;
 305 }
 306
 307 static struct spi_driver tle62x0_driver = {
 308         .driver = {
 309                 .name   = "tle62x0",
 310                 .owner  = THIS_MODULE,
 311         },
 312         .probe          = tle62x0_probe,
 313         .remove         = __devexit_p(tle62x0_remove),
 314 };
 315
 316 static __init int tle62x0_init(void)
 317 {
 318         return spi_register_driver(&tle62x0_driver);
 319 }
 320
 321 static __exit void tle62x0_exit(void)
 322 {
 323         spi_unregister_driver(&tle62x0_driver);
 324 }
 325
 326 module_init(tle62x0_init);
 327 module_exit(tle62x0_exit);
 328
 329 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 330 MODULE_DESCRIPTION("TLE62x0 SPI driver");
 331 MODULE_LICENSE("GPL v2");
 332 MODULE_ALIAS("spi:tle62x0");