By setting "reset_type" to one of the following values, the default
software reset mechanism may be overidden. Here the possible values of
"reset_type":
1 - PPC4xx core reset
2 - PPC4xx chip reset
3 - PPC4xx system reset (default)
This will be used by a new PPC440SPe board port, which needs a "chip
reset" instead of the default "system reset" to be asserted.
Signed-off-by: Stefan Roese <s...@denx.de>
Cc: Josh Boyer <jwbo...@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
---
v2:
- Add small property description to Documentation
- Add sanity check for property value
Documentation/powerpc/dts-bindings/4xx/reboot.txt | 18 +++++++++++++++
arch/powerpc/sysdev/ppc4xx_soc.c | 24 +++++++++++++++++++-
2 files changed, 40 insertions(+), 2 deletions(-)
create mode 100644 Documentation/powerpc/dts-bindings/4xx/reboot.txt
diff --git a/Documentation/powerpc/dts-bindings/4xx/reboot.txt
b/Documentation/powerpc/dts-bindings/4xx/reboot.txt
new file mode 100644
index 0000000..d721726
--- /dev/null
+++ b/Documentation/powerpc/dts-bindings/4xx/reboot.txt
@@ -0,0 +1,18 @@
+Reboot property to control system reboot on PPC4xx systems:
+
+By setting "reset_type" to one of the following values, the default
+software reset mechanism may be overidden. Here the possible values of
+"reset_type":
+
+ 1 - PPC4xx core reset
+ 2 - PPC4xx chip reset
+ 3 - PPC4xx system reset (default)
+
+Example:
+
+ c...@0 {
+ device_type = "cpu";
+ model = "PowerPC,440SPe";
+ ...
+ reset-type = <2>; /* Use chip-reset */
+ };
diff --git a/arch/powerpc/sysdev/ppc4xx_soc.c b/arch/powerpc/sysdev/ppc4xx_soc.c
index 5c01435..d3d6ce3 100644
--- a/arch/powerpc/sysdev/ppc4xx_soc.c
+++ b/arch/powerpc/sysdev/ppc4xx_soc.c
@@ -191,11 +191,31 @@ static int __init ppc4xx_l2c_probe(void)
arch_initcall(ppc4xx_l2c_probe);
/*
- * At present, this routine just applies a system reset.
+ * Apply a system reset. Alternatively a board specific value may be
+ * provided via the "reset-type" property in the cpu node.
*/
void ppc4xx_reset_system(char *cmd)
{
- mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_RST_SYSTEM);
+ struct device_node *np;
+ u32 reset_type = DBCR0_RST_SYSTEM;
+ const u32 *prop;
+
+ np = of_find_node_by_type(NULL, "cpu");
+ if (np) {
+ prop = of_get_property(np, "reset-type", NULL);
+
+ /*
+ * Check if property exists and if it is in range:
+ * 1 - PPC4xx core reset
+ * 2 - PPC4xx chip reset
+ * 3 - PPC4xx system reset (default)
+ */
+ if ((prop) && ((prop[0] >= 1) && (prop[0] <= 3)))
+ reset_type = prop[0] << 28;
+ }
+
+ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | reset_type);
+
while (1)
; /* Just in case the reset doesn't work */
}
--
1.7.1
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