summaryrefslogtreecommitdiff
path: root/drivers/media/dvb/frontends/dib0070.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/media/dvb/frontends/dib0070.c')
-rw-r--r--drivers/media/dvb/frontends/dib0070.c37
1 files changed, 30 insertions, 7 deletions
diff --git a/drivers/media/dvb/frontends/dib0070.c b/drivers/media/dvb/frontends/dib0070.c
index 1d47d4da7d4c..dc1cb17a6ea7 100644
--- a/drivers/media/dvb/frontends/dib0070.c
+++ b/drivers/media/dvb/frontends/dib0070.c
@@ -27,6 +27,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/i2c.h>
+#include <linux/mutex.h>
#include "dvb_frontend.h"
@@ -78,10 +79,18 @@ struct dib0070_state {
struct i2c_msg msg[2];
u8 i2c_write_buffer[3];
u8 i2c_read_buffer[2];
+ struct mutex i2c_buffer_lock;
};
-static uint16_t dib0070_read_reg(struct dib0070_state *state, u8 reg)
+static u16 dib0070_read_reg(struct dib0070_state *state, u8 reg)
{
+ u16 ret;
+
+ if (mutex_lock_interruptible(&state->i2c_buffer_lock) < 0) {
+ dprintk("could not acquire lock");
+ return 0;
+ }
+
state->i2c_write_buffer[0] = reg;
memset(state->msg, 0, 2 * sizeof(struct i2c_msg));
@@ -96,13 +105,23 @@ static uint16_t dib0070_read_reg(struct dib0070_state *state, u8 reg)
if (i2c_transfer(state->i2c, state->msg, 2) != 2) {
printk(KERN_WARNING "DiB0070 I2C read failed\n");
- return 0;
- }
- return (state->i2c_read_buffer[0] << 8) | state->i2c_read_buffer[1];
+ ret = 0;
+ } else
+ ret = (state->i2c_read_buffer[0] << 8)
+ | state->i2c_read_buffer[1];
+
+ mutex_unlock(&state->i2c_buffer_lock);
+ return ret;
}
static int dib0070_write_reg(struct dib0070_state *state, u8 reg, u16 val)
{
+ int ret;
+
+ if (mutex_lock_interruptible(&state->i2c_buffer_lock) < 0) {
+ dprintk("could not acquire lock");
+ return -EINVAL;
+ }
state->i2c_write_buffer[0] = reg;
state->i2c_write_buffer[1] = val >> 8;
state->i2c_write_buffer[2] = val & 0xff;
@@ -115,9 +134,12 @@ static int dib0070_write_reg(struct dib0070_state *state, u8 reg, u16 val)
if (i2c_transfer(state->i2c, state->msg, 1) != 1) {
printk(KERN_WARNING "DiB0070 I2C write failed\n");
- return -EREMOTEIO;
- }
- return 0;
+ ret = -EREMOTEIO;
+ } else
+ ret = 0;
+
+ mutex_unlock(&state->i2c_buffer_lock);
+ return ret;
}
#define HARD_RESET(state) do { \
@@ -734,6 +756,7 @@ struct dvb_frontend *dib0070_attach(struct dvb_frontend *fe, struct i2c_adapter
state->cfg = cfg;
state->i2c = i2c;
state->fe = fe;
+ mutex_init(&state->i2c_buffer_lock);
fe->tuner_priv = state;
if (dib0070_reset(fe) != 0)