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>

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>
Philipp Tomsich
1 parent 884ad05d34
Showing 2 changed files with 50 additions and 0 deletions Side-by-side Diff
board/theobroma-systems/puma_rk3399/puma-rk3399.c
doc/device-tree-bindings/config.txt
@@ -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 @@
 	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
@@ -46,4 +46,10 @@
 	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.
...	...	@@ -11,7 +11,10 @@
11	11	#include <usb.h>
12	12	#include <dm/pinctrl.h>
13	13	#include <dm/uclass-internal.h>
	14	+#include <asm/gpio.h>
14	15	#include <asm/setup.h>
	16	+#include <asm/arch/clock.h>
	17	+#include <asm/arch/cru_rk3399.h>
15	18	#include <asm/arch/periph.h>
16	19	#include <power/regulator.h>
17	20	#include <u-boot/sha256.h>
18	21
...	...	@@ -33,9 +36,50 @@
33	36	return 0;
34	37	}
35	38
	39	+static void rk3399_force_power_on_reset(void)
	40	+{
	41	+ ofnode node;
	42	+ struct gpio_desc sysreset_gpio;
	43	+
	44	+ debug("%s: trying to force a power-on reset\n", __func__);
	45	+
	46	+ node = ofnode_path("/config");
	47	+ if (!ofnode_valid(node)) {
	48	+ debug("%s: no /config node?\n", __func__);
	49	+ return;
	50	+ }
	51	+
	52	+ if (gpio_request_by_name_nodev(node, "sysreset-gpio", 0,
	53	+ &sysreset_gpio, GPIOD_IS_OUT)) {
	54	+ debug("%s: could not find a /config/sysreset-gpio\n", __func__);
	55	+ return;
	56	+ }
	57	+
	58	+ dm_gpio_set_value(&sysreset_gpio, 1);
	59	+}
	60	+
36	61	void spl_board_init(void)
37	62	{
38	63	int ret;
	64	+ struct rk3399_cru *cru = rockchip_get_cru();
	65	+
	66	+ /*
	67	+ * The RK3399 resets only 'almost all logic' (see also in the TRM
	68	+ * "3.9.4 Global software reset"), when issuing a software reset.
	69	+ * This may cause issues during boot-up for some configurations of
	70	+ * the application software stack.
	71	+ *
	72	+ * To work around this, we test whether the last reset reason was
	73	+ * a power-on reset and (if not) issue an overtemp-reset to reset
	74	+ * the entire module.
	75	+ *
	76	+ * While this was previously fixed by modifying the various places
	77	+ * that could generate a software reset (e.g. U-Boot's sysreset
	78	+ * driver, the ATF or Linux), we now have it here to ensure that
	79	+ * we no longer have to track this through the various components.
	80	+ */
	81	+ if (cru->glb_rst_st != 0)
	82	+ rk3399_force_power_on_reset();
39	83
40	84	/*
41	85	* Turning the eMMC and SPI back on (if disabled via the Qseven
...	...	@@ -46,4 +46,10 @@
46	46	If present (and SPL is controlled by the device-tree), this allows
47	47	to override the CONFIG_SYS_SPI_U_BOOT_OFFS setting using a value
48	48	from the device-tree.
	49	+
	50	+sysreset-gpio
	51	+ If present (and supported by the specific board), indicates a
	52	+ GPIO that can be set to trigger a system reset. It is assumed
	53	+ that such a system reset will effect a complete platform reset,
	54	+ being roughly equivalent to a power-on reset.