From de0c91e7a7605b047d3dc96f9e1c02701af6d716 Mon Sep 17 00:00:00 2001 From: Jakob Unterwurzacher Date: Tue, 17 Jun 2025 10:42:52 +0200 Subject: [PATCH] board: rockchip: unblock CAN bus in spl_board_init on Jaguar GPIO0_B7 is routed to TXI of the on-board CAN transceiver. The line has a pull-down per SoC default. This means the CAN transceiver transmits a dominant zero and blocks the CAN bus until Linux boots and reconfigures the pin. Let's switch to pull-up as soon as we can (i.e. in SPL). This cuts down the "bus is blocked" time from 10 seconds to < 1 second. Of course, to this needs CONFIG_SPL_BOARD_INIT, so enable it the Jaguar defconfig. Signed-off-by: Jakob Unterwurzacher Reviewed-by: Kever Yang --- .../jaguar_rk3588/jaguar_rk3588.c | 19 +++++++++++++++++++ configs/jaguar-rk3588_defconfig | 1 + 2 files changed, 20 insertions(+) diff --git a/board/theobroma-systems/jaguar_rk3588/jaguar_rk3588.c b/board/theobroma-systems/jaguar_rk3588/jaguar_rk3588.c index a6d44f10db3..3f484646701 100644 --- a/board/theobroma-systems/jaguar_rk3588/jaguar_rk3588.c +++ b/board/theobroma-systems/jaguar_rk3588/jaguar_rk3588.c @@ -51,3 +51,22 @@ int rockchip_early_misc_init_r(void) return 0; } + +#define GPIO0B7_PU_EN BIT(15) + +void spl_board_init(void) +{ + /* + * GPIO0_B7 is routed to CAN TX. This SoC pin has a pull-down per default. + * So on power-up, we block the CAN bus with a dominant zero. We want to keep + * this blocking time to a minimum, so we want to get this pin high in SPL. + * + * The CAN driver in Linux disables the pull-down and sets the pin to + * output high. We don't have a CAN driver in U-Boot and don't need one, + * so we just use the easiest way to get the pin high, which is setting a + * pull-up. + */ + struct rk3588_pmu2_ioc * const ioc = (void *)PMU2_IOC_BASE; + + rk_setreg(&ioc->gpio0b_p, GPIO0B7_PU_EN); +} diff --git a/configs/jaguar-rk3588_defconfig b/configs/jaguar-rk3588_defconfig index 378c48963f7..3ed07d18e10 100644 --- a/configs/jaguar-rk3588_defconfig +++ b/configs/jaguar-rk3588_defconfig @@ -27,6 +27,7 @@ CONFIG_DEFAULT_FDT_FILE="rockchip/rk3588-jaguar.dtb" CONFIG_DISPLAY_BOARDINFO_LATE=y CONFIG_CYCLIC=y CONFIG_SPL_MAX_SIZE=0x40000 +CONFIG_SPL_BOARD_INIT=y # CONFIG_SPL_RAW_IMAGE_SUPPORT is not set CONFIG_SPL_ATF=y # CONFIG_BOOTM_NETBSD is not set -- 2.47.3