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https://github.com/brain-hackers/u-boot-brain
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3d1957f0ea
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>
78 lines
2.5 KiB
Plaintext
78 lines
2.5 KiB
Plaintext
config DM_I2C
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bool "Enable Driver Model for I2C drivers"
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depends on DM
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help
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Enable driver model for I2C. The I2C uclass interface: probe, read,
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write and speed, is implemented with the bus drivers operations,
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which provide methods for bus setting and data transfer. Each chip
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device (bus child) info is kept as parent platdata. The interface
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is defined in include/i2c.h. When i2c bus driver supports the i2c
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uclass, but the device drivers not, then DM_I2C_COMPAT config can
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be used as compatibility layer.
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config DM_I2C_COMPAT
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bool "Enable I2C compatibility layer"
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depends on DM
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help
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Enable old-style I2C functions for compatibility with existing code.
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This option can be enabled as a temporary measure to avoid needing
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to convert all code for a board in a single commit. It should not
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be enabled for any board in an official release.
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config DM_I2C_GPIO
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bool "Enable Driver Model for software emulated I2C bus driver"
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depends on DM_I2C && DM_GPIO
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help
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Enable the i2c bus driver emulation by using the GPIOs. The bus GPIO
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configuration is given by the device tree. Kernel-style device tree
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bindings are supported.
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Binding info: doc/device-tree-bindings/i2c/i2c-gpio.txt
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config SYS_I2C_SANDBOX
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bool "Sandbox I2C driver"
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depends on SANDBOX && DM_I2C
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help
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Enable I2C support for sandbox. This is an emulation of a real I2C
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bus. Devices can be attached to the bus using the device tree
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which specifies the driver to use. As an example, see this device
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tree fragment from sandbox.dts. It shows that the I2C bus has a
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single EEPROM at address 0x2c (7-bit address) which is emulated by
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the driver for "sandbox,i2c-eeprom", which is in
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drivers/misc/i2c_eeprom_emul.c.
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i2c@0 {
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#address-cells = <1>;
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#size-cells = <0>;
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reg = <0>;
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compatible = "sandbox,i2c";
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clock-frequency = <400000>;
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eeprom@2c {
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reg = <0x2c>;
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compatible = "i2c-eeprom";
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emul {
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compatible = "sandbox,i2c-eeprom";
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sandbox,filename = "i2c.bin";
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sandbox,size = <128>;
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};
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};
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};
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config SYS_I2C_UNIPHIER
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bool "UniPhier I2C driver"
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depends on ARCH_UNIPHIER && DM_I2C
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default y
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help
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Support for UniPhier I2C controller driver. This I2C controller
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is used on PH1-LD4, PH1-sLD8 or older UniPhier SoCs.
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config SYS_I2C_UNIPHIER_F
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bool "UniPhier FIFO-builtin I2C driver"
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depends on ARCH_UNIPHIER && DM_I2C
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default y
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help
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Support for UniPhier FIFO-builtin I2C controller driver.
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This I2C controller is used on PH1-Pro4 or newer UniPhier SoCs.
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source "drivers/i2c/muxes/Kconfig"
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