diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.14/950-0277-overlays-Add-combine-option-to-i2c-overlays.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.14/950-0277-overlays-Add-combine-option-to-i2c-overlays.patch | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.14/950-0277-overlays-Add-combine-option-to-i2c-overlays.patch b/target/linux/brcm2708/patches-4.14/950-0277-overlays-Add-combine-option-to-i2c-overlays.patch new file mode 100644 index 0000000000..3981686cc8 --- /dev/null +++ b/target/linux/brcm2708/patches-4.14/950-0277-overlays-Add-combine-option-to-i2c-overlays.patch @@ -0,0 +1,104 @@ +From 1b02fe3ab446613cadcfac08d611b90becb02189 Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.org> +Date: Wed, 18 Apr 2018 17:04:23 +0100 +Subject: [PATCH 277/454] overlays: Add 'combine' option to i2c overlays + +The i2c0-bcm2708 and i2c1-bcm2708 overlays allow the I2C pin usage to +be changed. The names also suggest they revert to the old i2c_bcm2708 +driver, but they don't. The newer i2c_bcm2835 driver forces +transactions to be combined where possible, but this breaks some +devices. + +Add an option to disable transaction combining, which is currently +implemented by reverting to the old driver. + +See: https://github.com/raspberrypi/firmware/issues/828 + +Signed-off-by: Phil Elwell <phil@raspberrypi.org> +--- + arch/arm/boot/dts/overlays/README | 12 ++++++++++-- + arch/arm/boot/dts/overlays/i2c0-bcm2708-overlay.dts | 8 ++++++++ + arch/arm/boot/dts/overlays/i2c1-bcm2708-overlay.dts | 9 +++++++++ + 3 files changed, 27 insertions(+), 2 deletions(-) + +--- a/arch/arm/boot/dts/overlays/README ++++ b/arch/arm/boot/dts/overlays/README +@@ -865,8 +865,9 @@ Params: addr Set the + + + Name: i2c0-bcm2708 +-Info: Enable the i2c_bcm2708 driver for the i2c0 bus. Not all pin combinations +- are usable on all platforms. ++Info: Change i2c0 pin usage. Not all pin combinations are usable on all ++ platforms - platforms other then Compute Modules can only use this ++ to disable transaction combining. + Load: dtoverlay=i2c0-bcm2708,<param>=<val> + Params: sda0_pin GPIO pin for SDA0 (deprecated - use pins_*) + scl0_pin GPIO pin for SCL0 (deprecated - use pins_*) +@@ -874,15 +875,22 @@ Params: sda0_pin GPIO pin + pins_28_29 Use pins 28 and 29 + pins_44_45 Use pins 44 and 45 + pins_46_47 Use pins 46 and 47 ++ combine Allow transactions to be combined (default ++ "yes") + + + Name: i2c1-bcm2708 ++Info: Change i2c1 pin usage. Not all pin combinations are usable on all ++ platforms - platforms other then Compute Modules can only use this ++ to disable transaction combining. + Info: Enable the i2c_bcm2708 driver for the i2c1 bus + Load: dtoverlay=i2c1-bcm2708,<param>=<val> + Params: sda1_pin GPIO pin for SDA1 (2 or 44 - default 2) + scl1_pin GPIO pin for SCL1 (3 or 45 - default 3) + pin_func Alternative pin function (4 (alt0), 6 (alt2) - + default 4) ++ combine Allow transactions to be combined (default ++ "yes") + + + Name: i2s-gpio28-31 +--- a/arch/arm/boot/dts/overlays/i2c0-bcm2708-overlay.dts ++++ b/arch/arm/boot/dts/overlays/i2c0-bcm2708-overlay.dts +@@ -50,6 +50,13 @@ + }; + }; + ++ fragment@5 { ++ target = <&i2c0>; ++ __dormant__ { ++ compatible = "brcm,bcm2708-i2c"; ++ }; ++ }; ++ + __overrides__ { + sda0_pin = <&frag1>,"brcm,pins:0"; + scl0_pin = <&frag1>,"brcm,pins:4"; +@@ -57,5 +64,6 @@ + pins_28_29 = <0>,"-1+2-3-4"; + pins_44_45 = <0>,"-1-2+3-4"; + pins_46_47 = <0>,"-1-2-3+4"; ++ combine = <0>, "!5"; + }; + }; +--- a/arch/arm/boot/dts/overlays/i2c1-bcm2708-overlay.dts ++++ b/arch/arm/boot/dts/overlays/i2c1-bcm2708-overlay.dts +@@ -26,9 +26,18 @@ + brcm,function = <4>; /* alt 0 */ + }; + }; ++ ++ fragment@2 { ++ target = <&i2c1>; ++ __dormant__ { ++ compatible = "brcm,bcm2708-i2c"; ++ }; ++ }; ++ + __overrides__ { + sda1_pin = <&pins>,"brcm,pins:0"; + scl1_pin = <&pins>,"brcm,pins:4"; + pin_func = <&pins>,"brcm,function:0"; ++ combine = <0>, "!2"; + }; + }; |