[PATCH v2 08/22] interconnect: qcom: smd-rpm: Add rpmcc handling skeleton code

[Konrad Dybcio]

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);

Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
---
 drivers/interconnect/qcom/icc-rpm.h | 15 +++++++++++++++
 drivers/interconnect/qcom/smd-rpm.c | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/drivers/interconnect/qcom/icc-rpm.h b/drivers/interconnect/qcom/icc-rpm.h
index 9b4ea4e39b9f..aec192321411 100644
--- a/drivers/interconnect/qcom/icc-rpm.h
+++ b/drivers/interconnect/qcom/icc-rpm.h
@@ -22,6 +22,18 @@ 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
 
 /**
@@ -47,6 +59,7 @@ struct qcom_icc_provider {
 	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;
@@ -104,6 +117,7 @@ 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;
@@ -125,5 +139,6 @@ 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, u32 active_rate, u32 sleep_rate);
 
 #endif
diff --git a/drivers/interconnect/qcom/smd-rpm.c b/drivers/interconnect/qcom/smd-rpm.c
index b0183262ba66..6c51e346b326 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 +45,38 @@ 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, u32 active_rate, u32 sleep_rate)
+{
+	struct clk_smd_rpm_req req = {
+		.key = cpu_to_le32(QCOM_RPM_SMD_KEY_RATE),
+		.nbytes = cpu_to_le32(sizeof(u32)),
+	};
+	int ret;
+
+	/* Branch clocks are only on/off */
+	if (clk->branch) {
+		active_rate = !!active_rate;
+		sleep_rate = !!sleep_rate;
+	}
+
+	req.value = cpu_to_le32(active_rate);
+	ret = qcom_rpm_smd_write(icc_smd_rpm,
+				 QCOM_SMD_RPM_ACTIVE_STATE,
+				 clk->resource_type,
+				 clk->clock_id,
+				 &req, sizeof(req));
+	if (ret)
+		return ret;
+
+	req.value = cpu_to_le32(sleep_rate);
+	return qcom_rpm_smd_write(icc_smd_rpm,
+				  QCOM_SMD_RPM_SLEEP_STATE,
+				  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;
@@ -60,6 +93,10 @@ static int qcom_icc_rpm_smd_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
+	/* We need the clock driver to kick things off first to avoid ugly races */
+	if (!qcom_smd_rpm_scaling_available())
+		return -EPROBE_DEFER;
+
 	return 0;
 }
 

-- 
2.41.0