interconnect: qcom: smd-rpm: Add rpmcc handling skeleton code

Introduce qcom_icc_rpm_set_bus_rate() in preparation for handling RPM
clock resources within the interconnect framework. This lets us greatly
simplify all of the code handling, as setting the rate comes down to:

u32 rate_khz = max(clk.sleep_rate, clk.active_rate, clk_a.active_rate)
write_to_rpm(clock.description, rate_khz);

Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Georgi Djakov <djakov@kernel.org>
Link: https://lore.kernel.org/r/20230526-topic-smd_icc-v7-9-09c78c175546@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

2 files changed, 36 insertions, 0 deletions

diff --git a/drivers/interconnect/qcom/icc-rpm.h b/drivers/interconnect/qcom/icc-rpm.h
index 4755e422d2d1..5c43a8023ffa 100644
--- a/drivers/interconnect/qcom/icc-rpm.h
+++ b/drivers/interconnect/qcom/icc-rpm.h
@@ -25,6 +25,18 @@ enum qcom_icc_type {
 	QCOM_ICC_QNOC,
 };
 
+/**
+ * struct rpm_clk_resource - RPM bus clock resource
+ * @resource_type: RPM resource type of the clock resource
+ * @clock_id: index of the clock resource of a specific resource type
+ * @branch: whether the resource represents a branch clock
+*/
+struct rpm_clk_resource {
+	u32 resource_type;
+	u32 clock_id;
+	bool branch;
+};
+
 #define NUM_BUS_CLKS	2
 
 /**
@@ -50,6 +62,7 @@ struct qcom_icc_provider {
 	unsigned int qos_offset;
 	u64 bus_clk_rate[NUM_BUS_CLKS];
 	struct clk_bulk_data bus_clks[NUM_BUS_CLKS];
+	const struct rpm_clk_resource *bus_clk_desc;
 	struct clk_bulk_data *intf_clks;
 	bool keep_alive;
 	bool is_on;
@@ -107,6 +120,7 @@ struct qcom_icc_desc {
 	struct qcom_icc_node * const *nodes;
 	size_t num_nodes;
 	const char * const *bus_clocks;
+	const struct rpm_clk_resource *bus_clk_desc;
 	const char * const *intf_clocks;
 	size_t num_intf_clocks;
 	bool keep_alive;
@@ -128,5 +142,6 @@ int qnoc_remove(struct platform_device *pdev);
 
 bool qcom_icc_rpm_smd_available(void);
 int qcom_icc_rpm_smd_send(int ctx, int rsc_type, int id, u32 val);
+int qcom_icc_rpm_set_bus_rate(const struct rpm_clk_resource *clk, int ctx, u32 rate);
 
 #endif
diff --git a/drivers/interconnect/qcom/smd-rpm.c b/drivers/interconnect/qcom/smd-rpm.c
index b0183262ba66..24bc994e1a12 100644
--- a/drivers/interconnect/qcom/smd-rpm.c
+++ b/drivers/interconnect/qcom/smd-rpm.c
@@ -16,6 +16,7 @@
 #include "icc-rpm.h"
 
 #define RPM_KEY_BW		0x00007762
+#define QCOM_RPM_SMD_KEY_RATE	0x007a484b
 
 static struct qcom_smd_rpm *icc_smd_rpm;
 
@@ -44,6 +45,26 @@ int qcom_icc_rpm_smd_send(int ctx, int rsc_type, int id, u32 val)
 }
 EXPORT_SYMBOL_GPL(qcom_icc_rpm_smd_send);
 
+int qcom_icc_rpm_set_bus_rate(const struct rpm_clk_resource *clk, int ctx, u32 rate)
+{
+	struct clk_smd_rpm_req req = {
+		.key = cpu_to_le32(QCOM_RPM_SMD_KEY_RATE),
+		.nbytes = cpu_to_le32(sizeof(u32)),
+	};
+
+	/* Branch clocks are only on/off */
+	if (clk->branch)
+		rate = !!rate;
+
+	req.value = cpu_to_le32(rate);
+	return qcom_rpm_smd_write(icc_smd_rpm,
+				  ctx,
+				  clk->resource_type,
+				  clk->clock_id,
+				  &req, sizeof(req));
+}
+EXPORT_SYMBOL_GPL(qcom_icc_rpm_set_bus_rate);
+
 static int qcom_icc_rpm_smd_remove(struct platform_device *pdev)
 {
 	icc_smd_rpm = NULL;