diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0172-media-tc358743-Check-I2C-succeeded-during-probe.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.19/950-0172-media-tc358743-Check-I2C-succeeded-during-probe.patch | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0172-media-tc358743-Check-I2C-succeeded-during-probe.patch b/target/linux/brcm2708/patches-4.19/950-0172-media-tc358743-Check-I2C-succeeded-during-probe.patch new file mode 100644 index 0000000000..6cb1134b9d --- /dev/null +++ b/target/linux/brcm2708/patches-4.19/950-0172-media-tc358743-Check-I2C-succeeded-during-probe.patch @@ -0,0 +1,98 @@ +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; |