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
 111         dev_dbg(dev, "tle62x0_read() returned %d\n", ret);
 112
 113         for (ptr = 0; ptr < (st->nr_gpio * 2)/8; ptr += 1) {
 114                 fault <<= 8;
 115                 fault  |= ((unsigned long)buff[ptr]);
 116
 117                 dev_dbg(dev, "byte %d is %02x\n", ptr, buff[ptr]);
 118         }
 119
 120         for (ptr = 0; ptr < st->nr_gpio; ptr++) {
 121                 bp += sprintf(bp, "%s ", decode_fault(fault >> (ptr * 2)));
 122         }
 123
 124         *bp++ = '\n';
 125
 126         mutex_unlock(&st->lock);
 127         return bp - buf;
 128 }
 129
 130 static DEVICE_ATTR(status_show, S_IRUGO, tle62x0_status_show, NULL);
 131
 132 static ssize_t tle62x0_gpio_show(struct device *dev,
 133                 struct device_attribute *attr, char *buf)
 134 {
 135         struct tle62x0_state *st = dev_get_drvdata(dev);
 136         int gpio_num = to_gpio_num(attr);
 137         int value;
 138
 139         mutex_lock(&st->lock);
 140         value = (st->gpio_state >> gpio_num) & 1;
 141         mutex_unlock(&st->lock);
 142
 143         return snprintf(buf, PAGE_SIZE, "%d", value);
 144 }
 145
 146 static ssize_t tle62x0_gpio_store(struct device *dev,
 147                 struct device_attribute *attr,
 148                 const char *buf, size_t len)
 149 {
 150         struct tle62x0_state *st = dev_get_drvdata(dev);
 151         int gpio_num = to_gpio_num(attr);
 152         unsigned long val;
 153         char *endp;
 154
 155         val = simple_strtoul(buf, &endp, 0);
 156         if (buf == endp)
 157                 return -EINVAL;
 158
 159         dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);
 160
 161         mutex_lock(&st->lock);
 162
 163         if (val)
 164                 st->gpio_state |= 1 << gpio_num;
 165         else
 166                 st->gpio_state &= ~(1 << gpio_num);
 167
 168         tle62x0_write(st);
 169         mutex_unlock(&st->lock);
 170
 171         return len;
 172 }
 173
 174 static DEVICE_ATTR(gpio1, S_IWUSR|S_IRUGO,
 175                 tle62x0_gpio_show, tle62x0_gpio_store);
 176 static DEVICE_ATTR(gpio2, S_IWUSR|S_IRUGO,
 177                 tle62x0_gpio_show, tle62x0_gpio_store);
 178 static DEVICE_ATTR(gpio3, S_IWUSR|S_IRUGO,
 179                 tle62x0_gpio_show, tle62x0_gpio_store);
 180 static DEVICE_ATTR(gpio4, S_IWUSR|S_IRUGO,
 181                 tle62x0_gpio_show, tle62x0_gpio_store);
 182 static DEVICE_ATTR(gpio5, S_IWUSR|S_IRUGO,
 183                 tle62x0_gpio_show, tle62x0_gpio_store);
 184 static DEVICE_ATTR(gpio6, S_IWUSR|S_IRUGO,
 185                 tle62x0_gpio_show, tle62x0_gpio_store);
 186 static DEVICE_ATTR(gpio7, S_IWUSR|S_IRUGO,
 187                 tle62x0_gpio_show, tle62x0_gpio_store);
 188 static DEVICE_ATTR(gpio8, S_IWUSR|S_IRUGO,
 189                 tle62x0_gpio_show, tle62x0_gpio_store);
 190 static DEVICE_ATTR(gpio9, S_IWUSR|S_IRUGO,
 191                 tle62x0_gpio_show, tle62x0_gpio_store);
 192 static DEVICE_ATTR(gpio10, S_IWUSR|S_IRUGO,
 193                 tle62x0_gpio_show, tle62x0_gpio_store);
 194 static DEVICE_ATTR(gpio11, S_IWUSR|S_IRUGO,
 195                 tle62x0_gpio_show, tle62x0_gpio_store);
 196 static DEVICE_ATTR(gpio12, S_IWUSR|S_IRUGO,
 197                 tle62x0_gpio_show, tle62x0_gpio_store);
 198 static DEVICE_ATTR(gpio13, S_IWUSR|S_IRUGO,
 199                 tle62x0_gpio_show, tle62x0_gpio_store);
 200 static DEVICE_ATTR(gpio14, S_IWUSR|S_IRUGO,
 201                 tle62x0_gpio_show, tle62x0_gpio_store);
 202 static DEVICE_ATTR(gpio15, S_IWUSR|S_IRUGO,
 203                 tle62x0_gpio_show, tle62x0_gpio_store);
 204 static DEVICE_ATTR(gpio16, S_IWUSR|S_IRUGO,
 205                 tle62x0_gpio_show, tle62x0_gpio_store);
 206
 207 static struct device_attribute *gpio_attrs[] = {
 208         [0]             = &dev_attr_gpio1,
 209         [1]             = &dev_attr_gpio2,
 210         [2]             = &dev_attr_gpio3,
 211         [3]             = &dev_attr_gpio4,
 212         [4]             = &dev_attr_gpio5,
 213         [5]             = &dev_attr_gpio6,
 214         [6]             = &dev_attr_gpio7,
 215         [7]             = &dev_attr_gpio8,
 216         [8]             = &dev_attr_gpio9,
 217         [9]             = &dev_attr_gpio10,
 218         [10]            = &dev_attr_gpio11,
 219         [11]            = &dev_attr_gpio12,
 220         [12]            = &dev_attr_gpio13,
 221         [13]            = &dev_attr_gpio14,
 222         [14]            = &dev_attr_gpio15,
 223         [15]            = &dev_attr_gpio16
 224 };
 225
 226 static int to_gpio_num(struct device_attribute *attr)
 227 {
 228         int ptr;
 229
 230         for (ptr = 0; ptr < ARRAY_SIZE(gpio_attrs); ptr++) {
 231                 if (gpio_attrs[ptr] == attr)
 232                         return ptr;
 233         }
 234
 235         return -1;
 236 }
 237
 238 static int __devinit tle62x0_probe(struct spi_device *spi)
 239 {
 240         struct tle62x0_state *st;
 241         struct tle62x0_pdata *pdata;
 242         int ptr;
 243         int ret;
 244
 245         pdata = spi->dev.platform_data;
 246         if (pdata == NULL) {
 247                 dev_err(&spi->dev, "no device data specified\n");
 248                 return -EINVAL;
 249         }
 250
 251         st = kzalloc(sizeof(struct tle62x0_state), GFP_KERNEL);
 252         if (st == NULL) {
 253                 dev_err(&spi->dev, "no memory for device state\n");
 254                 return -ENOMEM;
 255         }
 256
 257         st->us = spi;
 258         st->nr_gpio = pdata->gpio_count;
 259         st->gpio_state = pdata->init_state;
 260
 261         mutex_init(&st->lock);
 262
 263         ret = device_create_file(&spi->dev, &dev_attr_status_show);
 264         if (ret) {
 265                 dev_err(&spi->dev, "cannot create status attribute\n");
 266                 goto err_status;
 267         }
 268
 269         for (ptr = 0; ptr < pdata->gpio_count; ptr++) {
 270                 ret = device_create_file(&spi->dev, gpio_attrs[ptr]);
 271                 if (ret) {
 272                         dev_err(&spi->dev, "cannot create gpio attribute\n");
 273                         goto err_gpios;
 274                 }
 275         }
 276
 277         /* tle62x0_write(st); */
 278         spi_set_drvdata(spi, st);
 279         return 0;
 280
 281  err_gpios:
 282         for (; ptr > 0; ptr--)
 283                 device_remove_file(&spi->dev, gpio_attrs[ptr]);
 284
 285         device_remove_file(&spi->dev, &dev_attr_status_show);
 286
 287  err_status:
 288         kfree(st);
 289         return ret;
 290 }
 291
 292 static int __devexit tle62x0_remove(struct spi_device *spi)
 293 {
 294         struct tle62x0_state *st = spi_get_drvdata(spi);
 295         int ptr;
 296
 297         for (ptr = 0; ptr < st->nr_gpio; ptr++)
 298                 device_remove_file(&spi->dev, gpio_attrs[ptr]);
 299
 300         kfree(st);
 301         return 0;
 302 }
 303
 304 static struct spi_driver tle62x0_driver = {
 305         .driver = {
 306                 .name   = "tle62x0",
 307                 .owner  = THIS_MODULE,
 308         },
 309         .probe          = tle62x0_probe,
 310         .remove         = __devexit_p(tle62x0_remove),
 311 };
 312
 313 static __init int tle62x0_init(void)
 314 {
 315         return spi_register_driver(&tle62x0_driver);
 316 }
 317
 318 static __exit void tle62x0_exit(void)
 319 {
 320         spi_unregister_driver(&tle62x0_driver);
 321 }
 322
 323 module_init(tle62x0_init);
 324 module_exit(tle62x0_exit);
 325
 326 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 327 MODULE_DESCRIPTION("TLE62x0 SPI driver");
 328 MODULE_LICENSE("GPL v2");