diff options
author | Przemyslaw Marczak <p.marczak@samsung.com> | 2015-03-31 19:57:18 +0300 |
---|---|---|
committer | Simon Glass <sjg@chromium.org> | 2015-04-18 20:11:17 +0300 |
commit | c54473cb25968be53e6b47527d5970b03a3cf41d (patch) | |
tree | 3bd25bfae1d777030122a441f585b20ba42a427f /doc/device-tree-bindings/i2c | |
parent | 705fcf4de40383a47dc92c4c9d7dbeb37a9d1104 (diff) | |
download | u-boot-c54473cb25968be53e6b47527d5970b03a3cf41d.tar.xz |
dm: i2c: add i2c-gpio driver
This commit adds driver model support to software emulated i2c bus driver.
This driver supports kernel-style device tree bindings. Fdt properties in use:
- compatible - "i2c-gpio"
- gpios - data and clock GPIO pin phandles
- delay-us - micro seconds delay between GPIOs toggle operations,
which is 1/4 of I2C speed clock period.
Added:
- Config: CONFIG_DM_I2C_GPIO
- File: drivers/i2c/i2c-gpio.c
- File: doc/device-tree-bindings/i2c/i2c-gpio.txt
Driver base code is taken from: drivers/i2c/soft-i2c.c, changes:
- use "i2c-gpio" naming
- update comments style
- move preprocesor macros into functions
- add device tree support
- add driver model i2c support
- code cleanup,
- add Kconfig entry
Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Added braces in i2c_gpio_xfer() to fix style nit:
Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'doc/device-tree-bindings/i2c')
-rw-r--r-- | doc/device-tree-bindings/i2c/i2c-gpio.txt | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/doc/device-tree-bindings/i2c/i2c-gpio.txt b/doc/device-tree-bindings/i2c/i2c-gpio.txt new file mode 100644 index 0000000000..ba56ed5dea --- /dev/null +++ b/doc/device-tree-bindings/i2c/i2c-gpio.txt @@ -0,0 +1,37 @@ +I2C gpio device binding +======================= + +Driver: +- drivers/i2c/i2c-gpio.c + +Software i2c device-tree node properties: +Required: +* #address-cells = <1>; +* #size-cells = <0>; +* compatible = "i2c-gpio"; +* gpios = <sda ...>, <scl ...>; + +Optional: +* i2c-gpio,delay-us = <5>; + The resulting transfer speed can be adjusted by setting the delay[us] + between gpio-toggle operations. Speed [Hz] = 1000000 / 4 * udelay[us], + It not defined, then default is 5us (~50KHz). + +Example: + +i2c-gpio@1 { + #address-cells = <1>; + #size-cells = <0>; + + compatible = "i2c-gpio"; + gpios = <&gpd1 0 GPIO_ACTIVE_HIGH>, /* SDA */ + <&gpd1 1 GPIO_ACTIVE_HIGH>; /* CLK */ + + i2c-gpio,delay-us = <5>; + + some_device@5 { + compatible = "some_device"; + reg = <0x5>; + ... + }; +}; |