[PATCH v3 0/3] Add I2C support on TH1520

[Drew Fustini]

On Tue, Jun 18, 2024 at 09:42:37AM +0200, Thomas Bonnefille wrote:
> This adds I2C support in the device tree of the T-Head TH1520 RISCV-SoC
> and a default configuration for the BeagleV-Ahead. It appears that the
> TH1520 I2C is already supported in the upstream kernel through the
> Synopsis Designware I2C adapter driver.
> 
> This patch depends on the clock patch from Drew Fustini
> Link: https://lore.kernel.org/linux-riscv/20240615-th1520-clk-v1-0-3ba4978c4d6b@tenstorrent.com
> and the pinctrl patch from Emil Renner Berthing
> Link: https://lore.kernel.org/linux-riscv/20240103132852.298964-1-emil.renner.berthing@canonical.com
> 
> Changed from v1:
> 1. Remove redundant example for Synopsis DesignWare-I2C bindings
> 2. Remove Node Ordering commit as it has already been taken
> 3. Remove EEPROM label
> 4. Rebase on pinctrl and clock driver patches
> 5. Add pinctrl configuration
> 6. Replaced the fixed-clock with a correct configuration
> 
> Changed from v2:
> 1. Reorder nodes to conserve ascending register node ordering
> 2. Add support for I2C2 as it probably use the same controller
> 3. Format comments to match kernel coding style
> 4. Reorder nodes to conserve alphabetical node ordering
> 6. Declare I2C2
> 6. Set pinctrl pull-up resistor to the highest value
> 
> Signed-off-by: Thomas Bonnefille <thomas.bonnefille at bootlin.com>
> ---
> Thomas Bonnefille (3):
>       dt-bindings: i2c: dw: Document compatible thead,th1520-i2c
>       riscv: dts: thead: Add TH1520 I2C nodes
>       riscv: dts: thead: Enable I2C on the BeagleV-Ahead
> 
>  .../bindings/i2c/snps,designware-i2c.yaml          |  4 ++
>  arch/riscv/boot/dts/thead/th1520-beaglev-ahead.dts | 84 ++++++++++++++++++++++
>  arch/riscv/boot/dts/thead/th1520.dtsi              | 60 ++++++++++++++++
>  3 files changed, 148 insertions(+)

The I2C controllers and the EEPROM probe okay on the BeagleV Ahead:

[    3.834654] i2c_dev: i2c /dev entries driver
[    4.037875] at24 0-0050: supply vcc not found, using dummy regulator
[    4.050303] at24 0-0050: 4096 byte 24c32 EEPROM, writable, 1 bytes/write

The EEPROM on I2C0 is working correctly:

# hexdump -C /sys/class/i2c-dev/i2c-0/device/0-0050/eeprom
[  196.438252] random: crng init done
00000000  42 45 41 47 4c 45 56 2d  41 48 45 41 44 2d 41 30  |BEAGLEV-AHEAD-A0|
00000010  0a ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000020  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
*
00001000

I did have to modify the .config to enable the necessary drivers.

Could you add patch that includes these in arch/riscv/configs/defconfig?

CONFIG_I2C_DESIGNWARE_CORE
CONFIG_I2C_DESIGNWARE_PLATFORM 
CONFIG_EEPROM_AT24

Thanks,
Drew