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