mirror of https://github.com/hak5/openwrt.git
99 lines
3.1 KiB
Diff
99 lines
3.1 KiB
Diff
From 6e089b7c2526037b0eaf9ecaed4d38957f33c19c Mon Sep 17 00:00:00 2001
|
|
From: Dave Stevenson <dave.stevenson@raspberrypi.org>
|
|
Date: Wed, 31 Oct 2018 14:57:34 +0000
|
|
Subject: [PATCH] media: tc358743: Check I2C succeeded during probe.
|
|
|
|
The probe for the TC358743 reads the CHIPID register from
|
|
the device and compares it to the expected value of 0.
|
|
If the I2C request fails then that also returns 0, so
|
|
the driver loads thinking that the device is there.
|
|
|
|
Generally I2C communications are reliable so there is
|
|
limited need to check the return value on every transfer,
|
|
therefore only amend the one read during probe to check
|
|
for I2C errors.
|
|
|
|
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
|
|
---
|
|
drivers/media/i2c/tc358743.c | 27 +++++++++++++++++++++++----
|
|
1 file changed, 23 insertions(+), 4 deletions(-)
|
|
|
|
--- a/drivers/media/i2c/tc358743.c
|
|
+++ b/drivers/media/i2c/tc358743.c
|
|
@@ -110,7 +110,7 @@ static inline struct tc358743_state *to_
|
|
|
|
/* --------------- I2C --------------- */
|
|
|
|
-static void i2c_rd(struct v4l2_subdev *sd, u16 reg, u8 *values, u32 n)
|
|
+static int i2c_rd(struct v4l2_subdev *sd, u16 reg, u8 *values, u32 n)
|
|
{
|
|
struct tc358743_state *state = to_state(sd);
|
|
struct i2c_client *client = state->i2c_client;
|
|
@@ -136,6 +136,7 @@ static void i2c_rd(struct v4l2_subdev *s
|
|
v4l2_err(sd, "%s: reading register 0x%x from 0x%x failed\n",
|
|
__func__, reg, client->addr);
|
|
}
|
|
+ return err != ARRAY_SIZE(msgs);
|
|
}
|
|
|
|
static void i2c_wr(struct v4l2_subdev *sd, u16 reg, u8 *values, u32 n)
|
|
@@ -192,15 +193,24 @@ static void i2c_wr(struct v4l2_subdev *s
|
|
}
|
|
}
|
|
|
|
-static noinline u32 i2c_rdreg(struct v4l2_subdev *sd, u16 reg, u32 n)
|
|
+static noinline u32 i2c_rdreg_err(struct v4l2_subdev *sd, u16 reg, u32 n,
|
|
+ int *err)
|
|
{
|
|
+ int error;
|
|
__le32 val = 0;
|
|
|
|
- i2c_rd(sd, reg, (u8 __force *)&val, n);
|
|
+ error = i2c_rd(sd, reg, (u8 __force *)&val, n);
|
|
+ if (err)
|
|
+ *err = error;
|
|
|
|
return le32_to_cpu(val);
|
|
}
|
|
|
|
+static inline u32 i2c_rdreg(struct v4l2_subdev *sd, u16 reg, u32 n)
|
|
+{
|
|
+ return i2c_rdreg_err(sd, reg, n, NULL);
|
|
+}
|
|
+
|
|
static noinline void i2c_wrreg(struct v4l2_subdev *sd, u16 reg, u32 val, u32 n)
|
|
{
|
|
__le32 raw = cpu_to_le32(val);
|
|
@@ -229,6 +239,13 @@ static u16 i2c_rd16(struct v4l2_subdev *
|
|
return i2c_rdreg(sd, reg, 2);
|
|
}
|
|
|
|
+static int i2c_rd16_err(struct v4l2_subdev *sd, u16 reg, u16 *value)
|
|
+{
|
|
+ int err;
|
|
+ *value = i2c_rdreg_err(sd, reg, 2, &err);
|
|
+ return err;
|
|
+}
|
|
+
|
|
static void i2c_wr16(struct v4l2_subdev *sd, u16 reg, u16 val)
|
|
{
|
|
i2c_wrreg(sd, reg, val, 2);
|
|
@@ -2054,6 +2071,7 @@ static int tc358743_probe(struct i2c_cli
|
|
struct tc358743_platform_data *pdata = client->dev.platform_data;
|
|
struct v4l2_subdev *sd;
|
|
u16 irq_mask = MASK_HDMI_MSK | MASK_CSI_MSK;
|
|
+ u16 chipid;
|
|
int err;
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
|
|
@@ -2086,7 +2104,8 @@ static int tc358743_probe(struct i2c_cli
|
|
sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
|
|
|
|
/* i2c access */
|
|
- if ((i2c_rd16(sd, CHIPID) & MASK_CHIPID) != 0) {
|
|
+ if (i2c_rd16_err(sd, CHIPID, &chipid) ||
|
|
+ (chipid & MASK_CHIPID) != 0) {
|
|
v4l2_info(sd, "not a TC358743 on address 0x%x\n",
|
|
client->addr << 1);
|
|
return -ENODEV;
|