[PATCH v5 11/16] mach-snapdragon: fixup power-domains

[Caleb Connolly]

We don't support the RPM(h)PD power domains in U-Boot, and we don't need
to - the necessary resources are on, and we aren't going to enter any
low power modes.

We could try using a no-op device, but this requires adding a compatible
for every platform, and just pollutes the driver model. So instead let's
just remove every "power-domains" property that references the RPM(h)pd
power controller. This takes <1ms as we're using OF_LIVE.

Of note, this only applies to drivers which are loading post-relocation.
Drivers loaded pre-reloc that reference the rpm(h)pd still need
DM_FLAG_DEFAULT_PD_CTRL_OFF in their flags.

Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
---
 arch/arm/mach-snapdragon/of_fixup.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/arch/arm/mach-snapdragon/of_fixup.c b/arch/arm/mach-snapdragon/of_fixup.c
index 4fdfed2dff16..3f7ac227bd09 100644
--- a/arch/arm/mach-snapdragon/of_fixup.c
+++ b/arch/arm/mach-snapdragon/of_fixup.c
@@ -21,8 +21,9 @@
 #include <dm/of_access.h>
 #include <dm/of.h>
 #include <fdt_support.h>
 #include <linux/errno.h>
+#include <stdlib.h>
 #include <time.h>
 
 /* U-Boot only supports USB high-speed mode on Qualcomm platforms with DWC3
  * USB controllers. Rather than requiring source level DT changes, we fix up
@@ -109,8 +110,38 @@ static void fixup_usb_nodes(void)
 			log_warning("Failed to fixup node %s: %d\n", glue_np->name, ret);
 	}
 }
 
+/* Remove all references to the rpmhpd device */
+static void fixup_power_domains(void)
+{
+	struct device_node *pd = NULL, *np = NULL;
+	struct property *prop;
+	const __be32 *val;
+
+	/* All Qualcomm platforms name the rpm(h)pd "power-controller" */
+	for_each_of_allnodes(pd) {
+		if (pd->name && !strcmp("power-controller", pd->name))
+			break;
+	}
+
+	/* Sanity check that this is indeed a power domain controller */
+	if (!of_find_property(pd, "#power-domain-cells", NULL)) {
+		log_err("Found power-controller but it doesn't have #power-domain-cells\n");
+		return;
+	}
+
+	/* Remove all references to the power domain controller */
+	for_each_of_allnodes(np) {
+		if (!(prop = of_find_property(np, "power-domains", NULL)))
+			continue;
+
+		val = prop->value;
+		if (val[0] == cpu_to_fdt32(pd->phandle))
+			of_remove_property(np, prop);
+	}
+}
+
 #define time_call(func, ...) \
 	do { \
 		u64 start = timer_get_us(); \
 		func(__VA_ARGS__); \
@@ -119,5 +150,6 @@ static void fixup_usb_nodes(void)
 
 void qcom_of_fixup_nodes(void)
 {
 	time_call(fixup_usb_nodes);
+	time_call(fixup_power_domains);
 }

-- 
2.44.0