interconnect: qcom: rpm: Handle interface clocks

Some (but not all) providers (or their specific nodes) require
specific clocks to be turned on before they can be accessed. Failure
to ensure that results in a seemingly random system crash (which
would usually happen at boot with the interconnect driver built-in),
resulting in the platform not booting up properly.

Limit the number of bus_clocks to 2 (which is the maximum that SMD
RPM interconnect supports anyway) and handle non-scaling clocks
separately. Update MSM8996 and SDM660 drivers to make sure they do
not regress with this change.

This unfortunately has to be done in one patch to prevent either
compile errors or broken bisect.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230518195801.2556998-1-konrad.dybcio@linaro.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>

Author: konradybcio

drivers/interconnect/qcom/icc-rpm.c

@@ -409,7 +409,7 @@ int qnoc_probe(struct platform_device *pdev)
 	struct qcom_icc_provider *qp;
 	struct icc_node *node;
 	size_t num_nodes, i;
-	const char * const *cds;
+	const char * const *cds = NULL;
 	int cd_num;
 	int ret;
 
@@ -424,28 +424,39 @@ int qnoc_probe(struct platform_device *pdev)
 	qnodes = desc->nodes;
 	num_nodes = desc->num_nodes;
 
-	if (desc->num_bus_clocks) {
-		cds = desc->bus_clocks;
-		cd_num = desc->num_bus_clocks;
+	if (desc->num_intf_clocks) {
+		cds = desc->intf_clocks;
+		cd_num = desc->num_intf_clocks;
 	} else {
-		cds = bus_clocks;
-		cd_num = ARRAY_SIZE(bus_clocks);
+		/* 0 intf clocks is perfectly fine */
+		cd_num = 0;
 	}
 
-	qp = devm_kzalloc(dev, struct_size(qp, bus_clks, cd_num), GFP_KERNEL);
+	qp = devm_kzalloc(dev, sizeof(*qp), GFP_KERNEL);
 	if (!qp)
 		return -ENOMEM;
 
-	qp->bus_clk_rate = devm_kcalloc(dev, cd_num, sizeof(*qp->bus_clk_rate),
-					GFP_KERNEL);
-	if (!qp->bus_clk_rate)
+	qp->intf_clks = devm_kzalloc(dev, sizeof(qp->intf_clks), GFP_KERNEL);
+	if (!qp->intf_clks)
 		return -ENOMEM;
 
 	data = devm_kzalloc(dev, struct_size(data, nodes, num_nodes),
 			    GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
+	qp->num_intf_clks = cd_num;
+	for (i = 0; i < cd_num; i++)
+		qp->intf_clks[i].id = cds[i];
+
+	if (desc->num_bus_clocks) {
+		cds = desc->bus_clocks;
+		cd_num = desc->num_bus_clocks;
+	} else {
+		cds = bus_clocks;
+		cd_num = ARRAY_SIZE(bus_clocks);
+	}
+
 	for (i = 0; i < cd_num; i++)
 		qp->bus_clks[i].id = cds[i];
 	qp->num_bus_clks = cd_num;
@@ -486,6 +497,10 @@ int qnoc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = devm_clk_bulk_get(dev, qp->num_intf_clks, qp->intf_clks);
+	if (ret)
+		return ret;
+
 	provider = &qp->provider;
 	provider->dev = dev;
 	provider->set = qcom_icc_set;
@@ -496,6 +511,11 @@ int qnoc_probe(struct platform_device *pdev)
 
 	icc_provider_init(provider);
 
+	/* If this fails, bus accesses will crash the platform! */
+	ret = clk_bulk_prepare_enable(qp->num_intf_clks, qp->intf_clks);
+	if (ret)
+		return ret;
+
 	for (i = 0; i < num_nodes; i++) {
 		size_t j;
 
@@ -524,6 +544,8 @@ int qnoc_probe(struct platform_device *pdev)
 	}
 	data->num_nodes = num_nodes;
 
+	clk_bulk_disable_unprepare(qp->num_intf_clks, qp->intf_clks);
+
 	ret = icc_provider_register(provider);
 	if (ret)
 		goto err_remove_nodes;

drivers/interconnect/qcom/icc-rpm.h

@@ -20,24 +20,32 @@ enum qcom_icc_type {
 	QCOM_ICC_QNOC,
 };
 
+#define NUM_BUS_CLKS	2
+
 /**
  * struct qcom_icc_provider - Qualcomm specific interconnect provider
  * @provider: generic interconnect provider
  * @num_bus_clks: the total number of bus_clks clk_bulk_data entries
+ * @num_intf_clks: the total number of intf_clks clk_bulk_data entries
  * @type: the ICC provider type
  * @regmap: regmap for QoS registers read/write access
  * @qos_offset: offset to QoS registers
  * @bus_clk_rate: bus clock rate in Hz
  * @bus_clks: the clk_bulk_data table of bus clocks
+ * @intf_clks: a clk_bulk_data array of interface clocks
+ * @is_on: whether the bus is powered on
  */
 struct qcom_icc_provider {
 	struct icc_provider provider;
 	int num_bus_clks;
+	int num_intf_clks;
 	enum qcom_icc_type type;
 	struct regmap *regmap;
 	unsigned int qos_offset;
-	u64 *bus_clk_rate;
-	struct clk_bulk_data bus_clks[];
+	u64 bus_clk_rate[NUM_BUS_CLKS];
+	struct clk_bulk_data bus_clks[NUM_BUS_CLKS];
+	struct clk_bulk_data *intf_clks;
+	bool is_on;
 };
 
 /**
@@ -93,6 +101,8 @@ struct qcom_icc_desc {
 	size_t num_nodes;
 	const char * const *bus_clocks;
 	size_t num_bus_clocks;
+	const char * const *intf_clocks;
+	size_t num_intf_clocks;
 	enum qcom_icc_type type;
 	const struct regmap_config *regmap_cfg;
 	unsigned int qos_offset;

drivers/interconnect/qcom/msm8996.c

@@ -21,21 +21,17 @@
 #include "smd-rpm.h"
 #include "msm8996.h"
 
-static const char * const bus_mm_clocks[] = {
-	"bus",
-	"bus_a",
+static const char * const mm_intf_clocks[] = {
 	"iface"
 };
 
-static const char * const bus_a0noc_clocks[] = {
+static const char * const a0noc_intf_clocks[] = {
 	"aggre0_snoc_axi",
 	"aggre0_cnoc_ahb",
 	"aggre0_noc_mpu_cfg"
 };
 
-static const char * const bus_a2noc_clocks[] = {
-	"bus",
-	"bus_a",
+static const char * const a2noc_intf_clocks[] = {
 	"aggre2_ufs_axi",
 	"ufs_axi"
 };
@@ -1821,8 +1817,8 @@ static const struct qcom_icc_desc msm8996_a0noc = {
 	.type = QCOM_ICC_NOC,
 	.nodes = a0noc_nodes,
 	.num_nodes = ARRAY_SIZE(a0noc_nodes),
-	.bus_clocks = bus_a0noc_clocks,
-	.num_bus_clocks = ARRAY_SIZE(bus_a0noc_clocks),
+	.intf_clocks = a0noc_intf_clocks,
+	.num_intf_clocks = ARRAY_SIZE(a0noc_intf_clocks),
 	.regmap_cfg = &msm8996_a0noc_regmap_config
 };
 
@@ -1865,8 +1861,8 @@ static const struct qcom_icc_desc msm8996_a2noc = {
 	.type = QCOM_ICC_NOC,
 	.nodes = a2noc_nodes,
 	.num_nodes = ARRAY_SIZE(a2noc_nodes),
-	.bus_clocks = bus_a2noc_clocks,
-	.num_bus_clocks = ARRAY_SIZE(bus_a2noc_clocks),
+	.intf_clocks = a2noc_intf_clocks,
+	.num_intf_clocks = ARRAY_SIZE(a2noc_intf_clocks),
 	.regmap_cfg = &msm8996_a2noc_regmap_config
 };
 
@@ -2004,8 +2000,8 @@ static const struct qcom_icc_desc msm8996_mnoc = {
 	.type = QCOM_ICC_NOC,
 	.nodes = mnoc_nodes,
 	.num_nodes = ARRAY_SIZE(mnoc_nodes),
-	.bus_clocks = bus_mm_clocks,
-	.num_bus_clocks = ARRAY_SIZE(bus_mm_clocks),
+	.intf_clocks = mm_intf_clocks,
+	.num_intf_clocks = ARRAY_SIZE(mm_intf_clocks),
 	.regmap_cfg = &msm8996_mnoc_regmap_config
 };
 

drivers/interconnect/qcom/sdm660.c

@@ -127,15 +127,11 @@ enum {
 	SDM660_SNOC,
 };
 
-static const char * const bus_mm_clocks[] = {
-	"bus",
-	"bus_a",
+static const char * const mm_intf_clocks[] = {
 	"iface",
 };
 
-static const char * const bus_a2noc_clocks[] = {
-	"bus",
-	"bus_a",
+static const char * const a2noc_intf_clocks[] = {
 	"ipa",
 	"ufs_axi",
 	"aggre2_ufs_axi",
@@ -1516,8 +1512,8 @@ static const struct qcom_icc_desc sdm660_a2noc = {
 	.type = QCOM_ICC_NOC,
 	.nodes = sdm660_a2noc_nodes,
 	.num_nodes = ARRAY_SIZE(sdm660_a2noc_nodes),
-	.bus_clocks = bus_a2noc_clocks,
-	.num_bus_clocks = ARRAY_SIZE(bus_a2noc_clocks),
+	.intf_clocks = a2noc_intf_clocks,
+	.num_intf_clocks = ARRAY_SIZE(a2noc_intf_clocks),
 	.regmap_cfg = &sdm660_a2noc_regmap_config,
 };
 
@@ -1659,8 +1655,8 @@ static const struct qcom_icc_desc sdm660_mnoc = {
 	.type = QCOM_ICC_NOC,
 	.nodes = sdm660_mnoc_nodes,
 	.num_nodes = ARRAY_SIZE(sdm660_mnoc_nodes),
-	.bus_clocks = bus_mm_clocks,
-	.num_bus_clocks = ARRAY_SIZE(bus_mm_clocks),
+	.intf_clocks = mm_intf_clocks,
+	.num_intf_clocks = ARRAY_SIZE(mm_intf_clocks),
 	.regmap_cfg = &sdm660_mnoc_regmap_config,
 };