[PATCH/RFC 02/14] firmware: arm_scmi: quirk: Handle bad clocks on R-Car X5H

[Geert Uytterhoeven]

Renesas R-Car X5H SCP FW SDKv4.28.0, v4.31.0, and v4.32.0 expose a few
clocks that do not support the CLOCK_ATTRIBUTES or CLOCK_DESCRIBE_RATES
command.  Since commit 0d8b0c8068a8ff5f ("firmware: arm_scmi: Harden
clock protocol initialization") in scmi/for-linux-next (next-20260319
and later), scmi_clock_attributes_get() or
scmi_clock_describe_rates_get() failures are no longer ignored, but
prevent the SCMI clock driver from initializing.

Hence add a quirk to ignore such failures, like before.  As the quirk
handling is harmless for unaffected systems, make it generic for all
R-Car X5H systems using SCP FW SDKv4.28.0 or later.

Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
---
 drivers/firmware/arm_scmi/clock.c  | 14 ++++++++++++++
 drivers/firmware/arm_scmi/quirks.c |  3 +++
 drivers/firmware/arm_scmi/quirks.h |  1 +
 3 files changed, 18 insertions(+)

diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index ce6f968925af38c0..d530882a0bac88c3 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -1232,6 +1232,18 @@ static const struct scmi_protocol_events clk_protocol_events = {
 	.num_events = ARRAY_SIZE(clk_events),
 };
 
+#define QUIRK_RCAR_X5H_NO_ATTRIBUTES					\
+	({								\
+		if (ret == -EREMOTEIO || ret == -EOPNOTSUPP)		\
+			continue;					\
+	})
+
+#define QUIRK_RCAR_X5H_NO_RATES						\
+	({								\
+		if (ret == -EOPNOTSUPP)					\
+			ret = 0;					\
+	})
+
 static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
 {
 	int clkid, ret;
@@ -1256,10 +1268,12 @@ static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
 	for (clkid = 0; clkid < cinfo->num_clocks; clkid++) {
 		cinfo->clkds[clkid].id = clkid;
 		ret = scmi_clock_attributes_get(ph, clkid, cinfo);
+		SCMI_QUIRK(clock_rcar_x5h_no_attributes, QUIRK_RCAR_X5H_NO_ATTRIBUTES);
 		if (ret)
 			return ret;
 
 		ret = scmi_clock_describe_rates_get(ph, clkid, cinfo);
+		SCMI_QUIRK(clock_rcar_x5h_no_attributes, QUIRK_RCAR_X5H_NO_RATES);
 		if (ret)
 			return ret;
 	}
diff --git a/drivers/firmware/arm_scmi/quirks.c b/drivers/firmware/arm_scmi/quirks.c
index c1a2f58505c1a757..e27c21b14220ab5f 100644
--- a/drivers/firmware/arm_scmi/quirks.c
+++ b/drivers/firmware/arm_scmi/quirks.c
@@ -171,6 +171,8 @@ struct scmi_quirk {
 
 /* Global Quirks Definitions */
 DEFINE_SCMI_QUIRK(clock_rates_triplet_out_of_spec, NULL, NULL, NULL);
+DEFINE_SCMI_QUIRK(clock_rcar_x5h_no_attributes, "Renesas", NULL, "0x10a0000-",
+		  "renesas,r8a78000");
 DEFINE_SCMI_QUIRK(perf_level_get_fc_force, "Qualcomm", NULL, "0x20000-");
 DEFINE_SCMI_QUIRK(power_rcar_x5h_4_28_bad_domains, "Renesas", NULL,
 		  "0x10a0000-0x10e0000", "renesas,r8a78000");
@@ -183,6 +185,7 @@ DEFINE_SCMI_QUIRK(power_rcar_x5h_4_28_bad_domains, "Renesas", NULL,
  */
 static struct scmi_quirk *scmi_quirks_table[] = {
 	__DECLARE_SCMI_QUIRK_ENTRY(clock_rates_triplet_out_of_spec),
+	__DECLARE_SCMI_QUIRK_ENTRY(clock_rcar_x5h_no_attributes),
 	__DECLARE_SCMI_QUIRK_ENTRY(perf_level_get_fc_force),
 	__DECLARE_SCMI_QUIRK_ENTRY(power_rcar_x5h_4_28_bad_domains),
 	NULL
diff --git a/drivers/firmware/arm_scmi/quirks.h b/drivers/firmware/arm_scmi/quirks.h
index 108c8d11f6043a61..67818b6cf0909f8e 100644
--- a/drivers/firmware/arm_scmi/quirks.h
+++ b/drivers/firmware/arm_scmi/quirks.h
@@ -47,6 +47,7 @@ static inline void scmi_quirks_enable(struct device *dev, const char *vend,
 
 /* Quirk delarations */
 DECLARE_SCMI_QUIRK(clock_rates_triplet_out_of_spec);
+DECLARE_SCMI_QUIRK(clock_rcar_x5h_no_attributes);
 DECLARE_SCMI_QUIRK(perf_level_get_fc_force);
 DECLARE_SCMI_QUIRK(power_rcar_x5h_4_28_bad_domains);
 
-- 
2.43.0