rockchip: rk3399-puma: add code to allow forcing a power-on reset

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>
This commit is contained in:
Philipp Tomsich 2017-11-28 17:56:11 +01:00
parent 884ad05d34
commit ae0d33a729
2 changed files with 50 additions and 0 deletions

View file

@ -11,7 +11,10 @@
#include <usb.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 <u-boot/sha256.h>
@ -33,9 +36,50 @@ 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

View file

@ -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.