U-Boot currently is missing GPIO support for FU540-C000 SoC which is mounted on HiFive Unleashed A00 board. This patch is intended to add DM based GPIO controller driver in order to access GPIO pins within the SoC using GPIO command in U-Boot. More details on the GPIO controller within the SoC can be found at[1]
The driver is based above master branch of u-boot-riscv.git and provides a method to configure Input/Output mode of the GPIO pin along with an option to set or clear state of the GPIO pin. The patch is available in dev/sagark/gpio_v4 branch here[2].
GPIO device node added to the mainline bound device tree for HiFive Unleashed is available in dev/sagark/mlv5.3-rc5 branch of repo here[3].
This implementation is ported from linux driver submitted for review at [4].
More details of GPIO pin routing on J1 header is available in schematic document[5]
[1] https://static.dev.sifive.com/FU540-C000-v1.0.pdf [2] https://github.com/sagsifive/u-boot [3] https://github.com/sagsifive/riscv-linux-hifive/ [4] https://lkml.org/lkml/2018/10/9/1103 [5] https://static.dev.sifive.com/dev-kits/hifive-unleashed/hifive-unleashed-a00...
Driver Testing: # Show status of all gpio's # Pin description will shown pins as unused/output/input. => gpio status -a Bank gpio@10060000_: gpio@10060000_0: unused: 0 [ ] gpio@10060000_1: unused: 0 [ ] ............................... ............................... ............................... gpio@10060000_15: unused: 0 [ ]
#Show status of pin 0 => gpio status gpio@10060000_0 Bank gpio@10060000_: gpio@10060000_0: unused: 0 [ ]
#Set GPIO1 high. =>gpio set 1 => gpio status gpio@10060000_1 Bank gpio@10060000_: gpio@10060000_1: output: 1 [ ]
#Set GPIO1 low =>gpio clear 0
#Toggle GPIO1 =>gpio toggle 1 #Toggle value of GPIO1 =>gpio toggle 1 #Toggle value of GPIO1
#Configure pin as input =>gpio input 3 #Configure gpio line 3 as input.
#Error check #16 is not a valid GPIO number for FU540-C000 so return error. =>gpio set 16 GPIO: '16' not found Command 'gpio' failed: Error -22
Patch history: v2: -Added get_function handler which is used by "gpio status" command. -Incorporated review comments on v1 patch series. -Updated driver testing information.
v1: -Set gpio_count either from the device tree or with a MACRO if ngpio's property is not mentioned in device node. -Check if gpio number passed from the command line is within the valid range. Incorporated review comment from Bin Meng -Renamed driver from fu540-gpio to sifive-gpio -Include a proper header file -Use dev->name as bank_name.
v0: Base version
Sagar Shrikant Kadam (2): gpio: sifive: add support for DM based gpio driver for FU540-SoC configs: fu540: enable gpio driver
arch/riscv/include/asm/arch-generic/gpio.h | 35 ++++++ arch/riscv/include/asm/gpio.h | 6 + board/sifive/fu540/Kconfig | 3 + drivers/gpio/Kconfig | 7 ++ drivers/gpio/Makefile | 1 + drivers/gpio/sifive-gpio.c | 177 +++++++++++++++++++++++++++++ 6 files changed, 229 insertions(+) create mode 100644 arch/riscv/include/asm/arch-generic/gpio.h create mode 100644 arch/riscv/include/asm/gpio.h create mode 100644 drivers/gpio/sifive-gpio.c