You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
104 lines
3.7 KiB
104 lines
3.7 KiB
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";
|
|
};
|
|
};
|
|
|