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path: root/drivers/i2c/chips/pcf8574.c
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Diffstat (limited to 'drivers/i2c/chips/pcf8574.c')
-rw-r--r--drivers/i2c/chips/pcf8574.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/i2c/chips/pcf8574.c b/drivers/i2c/chips/pcf8574.c
index 32b25427eaba..21c6dd69193c 100644
--- a/drivers/i2c/chips/pcf8574.c
+++ b/drivers/i2c/chips/pcf8574.c
@@ -48,14 +48,11 @@ static unsigned short normal_i2c[] = { 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26,
/* Insmod parameters */
I2C_CLIENT_INSMOD_2(pcf8574, pcf8574a);
-/* Initial values */
-#define PCF8574_INIT 255 /* All outputs on (input mode) */
-
/* Each client has this additional data */
struct pcf8574_data {
struct i2c_client client;
- u8 write; /* Remember last written value */
+ int write; /* Remember last written value */
};
static int pcf8574_attach_adapter(struct i2c_adapter *adapter);
@@ -85,7 +82,11 @@ static DEVICE_ATTR(read, S_IRUGO, show_read, NULL);
static ssize_t show_write(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pcf8574_data *data = i2c_get_clientdata(to_i2c_client(dev));
- return sprintf(buf, "%u\n", data->write);
+
+ if (data->write < 0)
+ return data->write;
+
+ return sprintf(buf, "%d\n", data->write);
}
static ssize_t set_write(struct device *dev, struct device_attribute *attr, const char *buf,
@@ -206,8 +207,7 @@ static int pcf8574_detach_client(struct i2c_client *client)
static void pcf8574_init_client(struct i2c_client *client)
{
struct pcf8574_data *data = i2c_get_clientdata(client);
- data->write = PCF8574_INIT;
- i2c_smbus_write_byte(client, data->write);
+ data->write = -EAGAIN;
}
static int __init pcf8574_init(void)