soc: qcom: geni-se: Introduce helper API for resource initialization

The GENI Serial Engine drivers (I2C, SPI, and SERIAL) currently duplicate
code for initializing shared resources such as clocks and interconnect
paths.

Introduce a new helper API, geni_se_resources_init(), to centralize this
initialization logic, improving modularity and simplifying the probe
function.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Tested-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
Link: https://lore.kernel.org/r/20260227061544.1785978-4-praveen.talari@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

2 files changed, 53 insertions, 0 deletions

diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
index b0542f836453..75e722cd1a94 100644
--- a/drivers/soc/qcom/qcom-geni-se.c
+++ b/drivers/soc/qcom/qcom-geni-se.c
@@ -19,6 +19,7 @@
 #include <linux/of_platform.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
+#include <linux/pm_opp.h>
 #include <linux/soc/qcom/geni-se.h>
 
 /**
@@ -1013,6 +1014,52 @@ int geni_icc_disable(struct geni_se *se)
 EXPORT_SYMBOL_GPL(geni_icc_disable);
 
 /**
+ * geni_se_resources_init() - Initialize resources for a GENI SE device.
+ * @se: Pointer to the geni_se structure representing the GENI SE device.
+ *
+ * This function initializes various resources required by the GENI Serial Engine
+ * (SE) device, including clock resources (core and SE clocks), interconnect
+ * paths for communication.
+ * It retrieves optional and mandatory clock resources, adds an OF-based
+ * operating performance point (OPP) table, and sets up interconnect paths
+ * with default bandwidths. The function also sets a flag (`has_opp`) to
+ * indicate whether OPP support is available for the device.
+ *
+ * Return: 0 on success, or a negative errno on failure.
+ */
+int geni_se_resources_init(struct geni_se *se)
+{
+	int ret;
+
+	se->core_clk = devm_clk_get_optional(se->dev, "core");
+	if (IS_ERR(se->core_clk))
+		return dev_err_probe(se->dev, PTR_ERR(se->core_clk),
+				     "Failed to get optional core clk\n");
+
+	se->clk = devm_clk_get(se->dev, "se");
+	if (IS_ERR(se->clk) && !has_acpi_companion(se->dev))
+		return dev_err_probe(se->dev, PTR_ERR(se->clk),
+				     "Failed to get SE clk\n");
+
+	ret = devm_pm_opp_set_clkname(se->dev, "se");
+	if (ret)
+		return ret;
+
+	ret = devm_pm_opp_of_add_table(se->dev);
+	if (ret && ret != -ENODEV)
+		return dev_err_probe(se->dev, ret, "Failed to add OPP table\n");
+
+	se->has_opp = (ret == 0);
+
+	ret = geni_icc_get(se, "qup-memory");
+	if (ret)
+		return ret;
+
+	return geni_icc_set_bw_ab(se, GENI_DEFAULT_BW, GENI_DEFAULT_BW, GENI_DEFAULT_BW);
+}
+EXPORT_SYMBOL_GPL(geni_se_resources_init);
+
+/**
  * geni_find_protocol_fw() - Locate and validate SE firmware for a protocol.
  * @dev: Pointer to the device structure.
  * @fw: Pointer to the firmware image.
diff --git a/include/linux/soc/qcom/geni-se.h b/include/linux/soc/qcom/geni-se.h
index 980aabea2157..c182dd0f0bde 100644
--- a/include/linux/soc/qcom/geni-se.h
+++ b/include/linux/soc/qcom/geni-se.h
@@ -60,18 +60,22 @@ struct geni_icc_path {
  * @dev:		Pointer to the Serial Engine device
  * @wrapper:		Pointer to the parent QUP Wrapper core
  * @clk:		Handle to the core serial engine clock
+ * @core_clk:		Auxiliary clock, which may be required by a protocol
  * @num_clk_levels:	Number of valid clock levels in clk_perf_tbl
  * @clk_perf_tbl:	Table of clock frequency input to serial engine clock
  * @icc_paths:		Array of ICC paths for SE
+ * @has_opp:		Indicates if OPP is supported
  */
 struct geni_se {
 	void __iomem *base;
 	struct device *dev;
 	struct geni_wrapper *wrapper;
 	struct clk *clk;
+	struct clk *core_clk;
 	unsigned int num_clk_levels;
 	unsigned long *clk_perf_tbl;
 	struct geni_icc_path icc_paths[3];
+	bool has_opp;
 };
 
 /* Common SE registers */
@@ -535,6 +539,8 @@ int geni_icc_enable(struct geni_se *se);
 
 int geni_icc_disable(struct geni_se *se);
 
+int geni_se_resources_init(struct geni_se *se);
+
 int geni_load_se_firmware(struct geni_se *se, enum geni_se_protocol_type protocol);
 #endif
 #endif