The reset circuitry in the RK3399 only resets 'almost all logic' when a software reset is performed. To make our software maintenance easier in the future, we want to have the option (controlled by a DTS property) to force all reset causes other than a power-on reset to trigger a power-on reset via a GPIO trigger.
This adds the necessary support to the rk3399-puma (i.e. RK3399-Q7) board-support and the documentation for the new property (sysreset-gpio) within the /config-node.
Signed-off-by: Philipp Tomsich philipp.tomsich@theobroma-systems.com Tested-by: Klaus Goger klaus.goger@theobroma-systems.com Reviewed-by: Simon Glass sjg@chromium.org
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Changes in v2: - updated for review comments (i.e. simplified dm_gpio_is_valid check)
board/theobroma-systems/puma_rk3399/puma-rk3399.c | 44 +++++++++++++++++++++++ doc/device-tree-bindings/config.txt | 6 ++++ 2 files changed, 50 insertions(+)
diff --git a/board/theobroma-systems/puma_rk3399/puma-rk3399.c b/board/theobroma-systems/puma_rk3399/puma-rk3399.c index 2b4988e..6750b5e 100644 --- a/board/theobroma-systems/puma_rk3399/puma-rk3399.c +++ b/board/theobroma-systems/puma_rk3399/puma-rk3399.c @@ -9,7 +9,10 @@ #include <misc.h> #include <dm/pinctrl.h> #include <dm/uclass-internal.h> +#include <asm/gpio.h> #include <asm/setup.h> +#include <asm/arch/clock.h> +#include <asm/arch/cru_rk3399.h> #include <asm/arch/periph.h> #include <power/regulator.h> #include <spl.h> @@ -32,9 +35,50 @@ int board_init(void) return 0; }
+static void rk3399_force_power_on_reset(void) +{ + ofnode node; + struct gpio_desc sysreset_gpio; + + debug("%s: trying to force a power-on reset\n", __func__); + + node = ofnode_path("/config"); + if (!ofnode_valid(node)) { + debug("%s: no /config node?\n", __func__); + return; + } + + if (gpio_request_by_name_nodev(node, "sysreset-gpio", 0, + &sysreset_gpio, GPIOD_IS_OUT)) { + debug("%s: could not find a /config/sysreset-gpio\n", __func__); + return; + } + + dm_gpio_set_value(&sysreset_gpio, 1); +} + void spl_board_init(void) { int ret; + struct rk3399_cru *cru = rockchip_get_cru(); + + /* + * The RK3399 resets only 'almost all logic' (see also in the TRM + * "3.9.4 Global software reset"), when issuing a software reset. + * This may cause issues during boot-up for some configurations of + * the application software stack. + * + * To work around this, we test whether the last reset reason was + * a power-on reset and (if not) issue an overtemp-reset to reset + * the entire module. + * + * While this was previously fixed by modifying the various places + * that could generate a software reset (e.g. U-Boot's sysreset + * driver, the ATF or Linux), we now have it here to ensure that + * we no longer have to track this through the various components. + */ + if (cru->glb_rst_st != 0) + rk3399_force_power_on_reset();
/* * Turning the eMMC and SPI back on (if disabled via the Qseven diff --git a/doc/device-tree-bindings/config.txt b/doc/device-tree-bindings/config.txt index 15e4349..6cdc16d 100644 --- a/doc/device-tree-bindings/config.txt +++ b/doc/device-tree-bindings/config.txt @@ -46,3 +46,9 @@ u-boot,spl-payload-offset If present (and SPL is controlled by the device-tree), this allows to override the CONFIG_SYS_SPI_U_BOOT_OFFS setting using a value from the device-tree. + +sysreset-gpio + If present (and supported by the specific board), indicates a + GPIO that can be set to trigger a system reset. It is assumed + that such a system reset will effect a complete platform reset, + being roughly equivalent to a power-on reset.