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| author | Gao Pan <b54642@freescale.com> | 2015-10-23 15:28:54 +0300 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2015-10-23 22:55:50 +0300 |
| commit | 1c4b6c3bcf30d0804db0d0647d8ebeb862c6f7e5 (patch) | |
| tree | a8773ecfa4e4f91be9bb41335d8326f78390fedb /Documentation/devicetree | |
| parent | 3861841d2205714bfabaee4efcbb5e4202884852 (diff) | |
| download | linux-1c4b6c3bcf30d0804db0d0647d8ebeb862c6f7e5.tar.xz | |
i2c: imx: implement bus recovery
Implement bus recovery methods for i2c-imx so we can recover from
situations where SCL/SDA are stuck low.
Once i2c bus SCL/SDA are stuck low during transfer, config the i2c
pinctrl to gpio mode by calling pinctrl sleep set function, and then
use GPIO to emulate the i2c protocol to send nine dummy clock to recover
i2c device. After recovery, set i2c pinctrl to default group setting.
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Gao Pan <b54642@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'Documentation/devicetree')
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-imx.txt | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx.txt b/Documentation/devicetree/bindings/i2c/i2c-imx.txt index ce4311d726ae..eab5836ba7f9 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-imx.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-imx.txt @@ -14,6 +14,10 @@ Optional properties: The absence of the propoerty indicates the default frequency 100 kHz. - dmas: A list of two dma specifiers, one for each entry in dma-names. - dma-names: should contain "tx" and "rx". +- scl-gpios: specify the gpio related to SCL pin +- sda-gpios: specify the gpio related to SDA pin +- pinctrl: add extra pinctrl to configure i2c pins to gpio function for i2c + bus recovery, call it "gpio" state Examples: @@ -37,4 +41,9 @@ i2c0: i2c@40066000 { /* i2c0 on vf610 */ dmas = <&edma0 0 50>, <&edma0 0 51>; dma-names = "rx","tx"; + pinctrl-names = "default", "gpio"; + pinctrl-0 = <&pinctrl_i2c1>; + pinctrl-1 = <&pinctrl_i2c1_gpio>; + scl-gpios = <&gpio5 26 GPIO_ACTIVE_HIGH>; + sda-gpios = <&gpio5 27 GPIO_ACTIVE_HIGH>; }; |