In Tegra186, the BPMP (Boot and Power Management Processor) owns certain
HW devices, such as the I2C controller for the power management I2C bus.
Software running on other CPUs must perform IPC to the BPMP in order to
execute transactions on that I2C bus. This binding describes an I2C bus
that is accessed in such a fashion.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Add a new I2C_MUX uclass. Devices in this class can multiplex between
several I2C buses, selecting them one at a time for use by the system.
The multiplexing mechanism is left to the driver to decide - it may be
controlled by GPIOs, for example.
The uclass supports only two methods: select() and deselect().
The current mux state is expected to be stored in the mux itself since
it is the only thing that knows how to make things work. The mux can
record the current state and then avoid switching unless it is necessary.
So select() can be skipped if the mux is already in the correct state.
Also deselect() can be made a nop if required.
Signed-off-by: Simon Glass <sjg@chromium.org>
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>
Since U-Boot can support different offset lengths (0-4 bytes), add a device
tree property to specify this. This avoids hard-coding it in the driver.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add U-Boot's peripheral clock information to the Tegra20 device tree file.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Songjun Wu
Stephen Warren
Moritz Fischer
Simon Glass
Przemyslaw Marczak
Wolfgang Denk