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