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linux/drivers/spi/tle62x0.c
David Brownell 822bd5aa2b tle62x0 driver stops ignoring read errors 
The tle62x0 driver was ignoring all read errors.  This patch makes it
pass such errors up the stack, instead of returning bogus data.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-14 18:45:42 -08:00

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/*
* tle62x0.c -- support Infineon TLE62x0 driver chips
*
* Copyright (c) 2007 Simtec Electronics
* Ben Dooks, <ben@simtec.co.uk>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/spi/tle62x0.h>
#define CMD_READ 0x00
#define CMD_SET 0xff
#define DIAG_NORMAL 0x03
#define DIAG_OVERLOAD 0x02
#define DIAG_OPEN 0x01
#define DIAG_SHORTGND 0x00
struct tle62x0_state {
struct spi_device *us;
struct mutex lock;
unsigned int nr_gpio;
unsigned int gpio_state;
unsigned char tx_buff[4];
unsigned char rx_buff[4];
};
static int to_gpio_num(struct device_attribute *attr);
static inline int tle62x0_write(struct tle62x0_state *st)
{
unsigned char *buff = st->tx_buff;
unsigned int gpio_state = st->gpio_state;
buff[0] = CMD_SET;
if (st->nr_gpio == 16) {
buff[1] = gpio_state >> 8;
buff[2] = gpio_state;
} else {
buff[1] = gpio_state;
}
dev_dbg(&st->us->dev, "buff %02x,%02x,%02x\n",
buff[0], buff[1], buff[2]);
return spi_write(st->us, buff, (st->nr_gpio == 16) ? 3 : 2);
}
static inline int tle62x0_read(struct tle62x0_state *st)
{
unsigned char *txbuff = st->tx_buff;
struct spi_transfer xfer = {
.tx_buf = txbuff,
.rx_buf = st->rx_buff,
.len = (st->nr_gpio * 2) / 8,
};
struct spi_message msg;
txbuff[0] = CMD_READ;
txbuff[1] = 0x00;
txbuff[2] = 0x00;
txbuff[3] = 0x00;
spi_message_init(&msg);
spi_message_add_tail(&xfer, &msg);
return spi_sync(st->us, &msg);
}
static unsigned char *decode_fault(unsigned int fault_code)
{
fault_code &= 3;
switch (fault_code) {
case DIAG_NORMAL:
return "N";
case DIAG_OVERLOAD:
return "V";
case DIAG_OPEN:
return "O";
case DIAG_SHORTGND:
return "G";
}
return "?";
}
static ssize_t tle62x0_status_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct tle62x0_state *st = dev_get_drvdata(dev);
char *bp = buf;
unsigned char *buff = st->rx_buff;
unsigned long fault = 0;
int ptr;
int ret;
mutex_lock(&st->lock);
ret = tle62x0_read(st);
dev_dbg(dev, "tle62x0_read() returned %d\n", ret);
if (ret < 0) {
mutex_unlock(&st->lock);
return ret;
}
for (ptr = 0; ptr < (st->nr_gpio * 2)/8; ptr += 1) {
fault <<= 8;
fault |= ((unsigned long)buff[ptr]);
dev_dbg(dev, "byte %d is %02x\n", ptr, buff[ptr]);
}
for (ptr = 0; ptr < st->nr_gpio; ptr++) {
bp += sprintf(bp, "%s ", decode_fault(fault >> (ptr * 2)));
}
*bp++ = '\n';
mutex_unlock(&st->lock);
return bp - buf;
}
static DEVICE_ATTR(status_show, S_IRUGO, tle62x0_status_show, NULL);
static ssize_t tle62x0_gpio_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct tle62x0_state *st = dev_get_drvdata(dev);
int gpio_num = to_gpio_num(attr);
int value;
mutex_lock(&st->lock);
value = (st->gpio_state >> gpio_num) & 1;
mutex_unlock(&st->lock);
return snprintf(buf, PAGE_SIZE, "%d", value);
}
static ssize_t tle62x0_gpio_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct tle62x0_state *st = dev_get_drvdata(dev);
int gpio_num = to_gpio_num(attr);
unsigned long val;
char *endp;
val = simple_strtoul(buf, &endp, 0);
if (buf == endp)
return -EINVAL;
dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);
mutex_lock(&st->lock);
if (val)
st->gpio_state |= 1 << gpio_num;
else
st->gpio_state &= ~(1 << gpio_num);
tle62x0_write(st);
mutex_unlock(&st->lock);
return len;
}
static DEVICE_ATTR(gpio1, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio2, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio3, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio4, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio5, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio6, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio7, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio8, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio9, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio10, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio11, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio12, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio13, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio14, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio15, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static DEVICE_ATTR(gpio16, S_IWUSR|S_IRUGO,
tle62x0_gpio_show, tle62x0_gpio_store);
static struct device_attribute *gpio_attrs[] = {
[0] = &dev_attr_gpio1,
[1] = &dev_attr_gpio2,
[2] = &dev_attr_gpio3,
[3] = &dev_attr_gpio4,
[4] = &dev_attr_gpio5,
[5] = &dev_attr_gpio6,
[6] = &dev_attr_gpio7,
[7] = &dev_attr_gpio8,
[8] = &dev_attr_gpio9,
[9] = &dev_attr_gpio10,
[10] = &dev_attr_gpio11,
[11] = &dev_attr_gpio12,
[12] = &dev_attr_gpio13,
[13] = &dev_attr_gpio14,
[14] = &dev_attr_gpio15,
[15] = &dev_attr_gpio16
};
static int to_gpio_num(struct device_attribute *attr)
{
int ptr;
for (ptr = 0; ptr < ARRAY_SIZE(gpio_attrs); ptr++) {
if (gpio_attrs[ptr] == attr)
return ptr;
}
return -1;
}
static int __devinit tle62x0_probe(struct spi_device *spi)
{
struct tle62x0_state *st;
struct tle62x0_pdata *pdata;
int ptr;
int ret;
pdata = spi->dev.platform_data;
if (pdata == NULL) {
dev_err(&spi->dev, "no device data specified\n");
return -EINVAL;
}
st = kzalloc(sizeof(struct tle62x0_state), GFP_KERNEL);
if (st == NULL) {
dev_err(&spi->dev, "no memory for device state\n");
return -ENOMEM;
}
st->us = spi;
st->nr_gpio = pdata->gpio_count;
st->gpio_state = pdata->init_state;
mutex_init(&st->lock);
ret = device_create_file(&spi->dev, &dev_attr_status_show);
if (ret) {
dev_err(&spi->dev, "cannot create status attribute\n");
goto err_status;
}
for (ptr = 0; ptr < pdata->gpio_count; ptr++) {
ret = device_create_file(&spi->dev, gpio_attrs[ptr]);
if (ret) {
dev_err(&spi->dev, "cannot create gpio attribute\n");
goto err_gpios;
}
}
/* tle62x0_write(st); */
spi_set_drvdata(spi, st);
return 0;
err_gpios:
for (; ptr > 0; ptr--)
device_remove_file(&spi->dev, gpio_attrs[ptr]);
device_remove_file(&spi->dev, &dev_attr_status_show);
err_status:
kfree(st);
return ret;
}
static int __devexit tle62x0_remove(struct spi_device *spi)
{
struct tle62x0_state *st = spi_get_drvdata(spi);
int ptr;
for (ptr = 0; ptr < st->nr_gpio; ptr++)
device_remove_file(&spi->dev, gpio_attrs[ptr]);
kfree(st);
return 0;
}
static struct spi_driver tle62x0_driver = {
.driver = {
.name = "tle62x0",
.owner = THIS_MODULE,
},
.probe = tle62x0_probe,
.remove = __devexit_p(tle62x0_remove),
};
static __init int tle62x0_init(void)
{
return spi_register_driver(&tle62x0_driver);
}
static __exit void tle62x0_exit(void)
{
spi_unregister_driver(&tle62x0_driver);
}
module_init(tle62x0_init);
module_exit(tle62x0_exit);
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_DESCRIPTION("TLE62x0 SPI driver");
MODULE_LICENSE("GPL v2");
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