Merge branch 'cpufreq/qcom-updates' into cpufreq/arm/linux-next

6 files changed, 414 insertions, 262 deletions

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 70c2b4bea55c..a905796f7f85 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -132,8 +132,8 @@ config ARM_OMAP2PLUS_CPUFREQ
 	depends on ARCH_OMAP2PLUS
 	default ARCH_OMAP2PLUS
 
-config ARM_QCOM_CPUFREQ_KRYO
-	tristate "Qualcomm Kryo based CPUFreq"
+config ARM_QCOM_CPUFREQ_NVMEM
+	tristate "Qualcomm nvmem based CPUFreq"
 	depends on ARM64
 	depends on QCOM_QFPROM
 	depends on QCOM_SMEM
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 7f2d2e1079d4..9a9f5ccd13d9 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -64,7 +64,7 @@ obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ)	+= omap-cpufreq.o
 obj-$(CONFIG_ARM_PXA2xx_CPUFREQ)	+= pxa2xx-cpufreq.o
 obj-$(CONFIG_PXA3xx)			+= pxa3xx-cpufreq.o
 obj-$(CONFIG_ARM_QCOM_CPUFREQ_HW)	+= qcom-cpufreq-hw.o
-obj-$(CONFIG_ARM_QCOM_CPUFREQ_KRYO)	+= qcom-cpufreq-kryo.o
+obj-$(CONFIG_ARM_QCOM_CPUFREQ_NVMEM)	+= qcom-cpufreq-nvmem.o
 obj-$(CONFIG_ARM_RASPBERRYPI_CPUFREQ) 	+= raspberrypi-cpufreq.o
 obj-$(CONFIG_ARM_S3C2410_CPUFREQ)	+= s3c2410-cpufreq.o
 obj-$(CONFIG_ARM_S3C2412_CPUFREQ)	+= s3c2412-cpufreq.o
diff --git a/drivers/cpufreq/cpufreq-dt-platdev.c b/drivers/cpufreq/cpufreq-dt-platdev.c
index d51bfef286e3..bca8d1f47fd2 100644
--- a/drivers/cpufreq/cpufreq-dt-platdev.c
+++ b/drivers/cpufreq/cpufreq-dt-platdev.c
@@ -127,6 +127,7 @@ static const struct of_device_id blacklist[] __initconst = {
 
 	{ .compatible = "qcom,apq8096", },
 	{ .compatible = "qcom,msm8996", },
+	{ .compatible = "qcom,qcs404", },
 
 	{ .compatible = "st,stih407", },
 	{ .compatible = "st,stih410", },
diff --git a/drivers/cpufreq/qcom-cpufreq-kryo.c b/drivers/cpufreq/qcom-cpufreq-kryo.c
deleted file mode 100644
index dd64dcf89c74..000000000000
--- a/drivers/cpufreq/qcom-cpufreq-kryo.c
+++ /dev/null
@@ -1,249 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (c) 2018, The Linux Foundation. All rights reserved.
- */
-
-/*
- * In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO processors,
- * the CPU frequency subset and voltage value of each OPP varies
- * based on the silicon variant in use. Qualcomm Process Voltage Scaling Tables
- * defines the voltage and frequency value based on the msm-id in SMEM
- * and speedbin blown in the efuse combination.
- * The qcom-cpufreq-kryo driver reads the msm-id and efuse value from the SoC
- * to provide the OPP framework with required information.
- * This is used to determine the voltage and frequency value for each OPP of
- * operating-points-v2 table when it is parsed by the OPP framework.
- */
-
-#include <linux/cpu.h>
-#include <linux/err.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/nvmem-consumer.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-#include <linux/pm_opp.h>
-#include <linux/slab.h>
-#include <linux/soc/qcom/smem.h>
-
-#define MSM_ID_SMEM	137
-
-enum _msm_id {
-	MSM8996V3 = 0xF6ul,
-	APQ8096V3 = 0x123ul,
-	MSM8996SG = 0x131ul,
-	APQ8096SG = 0x138ul,
-};
-
-enum _msm8996_version {
-	MSM8996_V3,
-	MSM8996_SG,
-	NUM_OF_MSM8996_VERSIONS,
-};
-
-static struct platform_device *cpufreq_dt_pdev, *kryo_cpufreq_pdev;
-
-static enum _msm8996_version qcom_cpufreq_kryo_get_msm_id(void)
-{
-	size_t len;
-	u32 *msm_id;
-	enum _msm8996_version version;
-
-	msm_id = qcom_smem_get(QCOM_SMEM_HOST_ANY, MSM_ID_SMEM, &len);
-	if (IS_ERR(msm_id))
-		return NUM_OF_MSM8996_VERSIONS;
-
-	/* The first 4 bytes are format, next to them is the actual msm-id */
-	msm_id++;
-
-	switch ((enum _msm_id)*msm_id) {
-	case MSM8996V3:
-	case APQ8096V3:
-		version = MSM8996_V3;
-		break;
-	case MSM8996SG:
-	case APQ8096SG:
-		version = MSM8996_SG;
-		break;
-	default:
-		version = NUM_OF_MSM8996_VERSIONS;
-	}
-
-	return version;
-}
-
-static int qcom_cpufreq_kryo_probe(struct platform_device *pdev)
-{
-	struct opp_table **opp_tables;
-	enum _msm8996_version msm8996_version;
-	struct nvmem_cell *speedbin_nvmem;
-	struct device_node *np;
-	struct device *cpu_dev;
-	unsigned cpu;
-	u8 *speedbin;
-	u32 versions;
-	size_t len;
-	int ret;
-
-	cpu_dev = get_cpu_device(0);
-	if (!cpu_dev)
-		return -ENODEV;
-
-	msm8996_version = qcom_cpufreq_kryo_get_msm_id();
-	if (NUM_OF_MSM8996_VERSIONS == msm8996_version) {
-		dev_err(cpu_dev, "Not Snapdragon 820/821!");
-		return -ENODEV;
-	}
-
-	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
-	if (!np)
-		return -ENOENT;
-
-	ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
-	if (!ret) {
-		of_node_put(np);
-		return -ENOENT;
-	}
-
-	speedbin_nvmem = of_nvmem_cell_get(np, NULL);
-	of_node_put(np);
-	if (IS_ERR(speedbin_nvmem)) {
-		if (PTR_ERR(speedbin_nvmem) != -EPROBE_DEFER)
-			dev_err(cpu_dev, "Could not get nvmem cell: %ld\n",
-				PTR_ERR(speedbin_nvmem));
-		return PTR_ERR(speedbin_nvmem);
-	}
-
-	speedbin = nvmem_cell_read(speedbin_nvmem, &len);
-	nvmem_cell_put(speedbin_nvmem);
-	if (IS_ERR(speedbin))
-		return PTR_ERR(speedbin);
-
-	switch (msm8996_version) {
-	case MSM8996_V3:
-		versions = 1 << (unsigned int)(*speedbin);
-		break;
-	case MSM8996_SG:
-		versions = 1 << ((unsigned int)(*speedbin) + 4);
-		break;
-	default:
-		BUG();
-		break;
-	}
-	kfree(speedbin);
-
-	opp_tables = kcalloc(num_possible_cpus(), sizeof(*opp_tables), GFP_KERNEL);
-	if (!opp_tables)
-		return -ENOMEM;
-
-	for_each_possible_cpu(cpu) {
-		cpu_dev = get_cpu_device(cpu);
-		if (NULL == cpu_dev) {
-			ret = -ENODEV;
-			goto free_opp;
-		}
-
-		opp_tables[cpu] = dev_pm_opp_set_supported_hw(cpu_dev,
-							      &versions, 1);
-		if (IS_ERR(opp_tables[cpu])) {
-			ret = PTR_ERR(opp_tables[cpu]);
-			dev_err(cpu_dev, "Failed to set supported hardware\n");
-			goto free_opp;
-		}
-	}
-
-	cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
-							  NULL, 0);
-	if (!IS_ERR(cpufreq_dt_pdev)) {
-		platform_set_drvdata(pdev, opp_tables);
-		return 0;
-	}
-
-	ret = PTR_ERR(cpufreq_dt_pdev);
-	dev_err(cpu_dev, "Failed to register platform device\n");
-
-free_opp:
-	for_each_possible_cpu(cpu) {
-		if (IS_ERR_OR_NULL(opp_tables[cpu]))
-			break;
-		dev_pm_opp_put_supported_hw(opp_tables[cpu]);
-	}
-	kfree(opp_tables);
-
-	return ret;
-}
-
-static int qcom_cpufreq_kryo_remove(struct platform_device *pdev)
-{
-	struct opp_table **opp_tables = platform_get_drvdata(pdev);
-	unsigned int cpu;
-
-	platform_device_unregister(cpufreq_dt_pdev);
-
-	for_each_possible_cpu(cpu)
-		dev_pm_opp_put_supported_hw(opp_tables[cpu]);
-
-	kfree(opp_tables);
-
-	return 0;
-}
-
-static struct platform_driver qcom_cpufreq_kryo_driver = {
-	.probe = qcom_cpufreq_kryo_probe,
-	.remove = qcom_cpufreq_kryo_remove,
-	.driver = {
-		.name = "qcom-cpufreq-kryo",
-	},
-};
-
-static const struct of_device_id qcom_cpufreq_kryo_match_list[] __initconst = {
-	{ .compatible = "qcom,apq8096", },
-	{ .compatible = "qcom,msm8996", },
-	{}
-};
-
-/*
- * Since the driver depends on smem and nvmem drivers, which may
- * return EPROBE_DEFER, all the real activity is done in the probe,
- * which may be defered as well. The init here is only registering
- * the driver and the platform device.
- */
-static int __init qcom_cpufreq_kryo_init(void)
-{
-	struct device_node *np = of_find_node_by_path("/");
-	const struct of_device_id *match;
-	int ret;
-
-	if (!np)
-		return -ENODEV;
-
-	match = of_match_node(qcom_cpufreq_kryo_match_list, np);
-	of_node_put(np);
-	if (!match)
-		return -ENODEV;
-
-	ret = platform_driver_register(&qcom_cpufreq_kryo_driver);
-	if (unlikely(ret < 0))
-		return ret;
-
-	kryo_cpufreq_pdev = platform_device_register_simple(
-		"qcom-cpufreq-kryo", -1, NULL, 0);
-	ret = PTR_ERR_OR_ZERO(kryo_cpufreq_pdev);
-	if (0 == ret)
-		return 0;
-
-	platform_driver_unregister(&qcom_cpufreq_kryo_driver);
-	return ret;
-}
-module_init(qcom_cpufreq_kryo_init);
-
-static void __exit qcom_cpufreq_kryo_exit(void)
-{
-	platform_device_unregister(kryo_cpufreq_pdev);
-	platform_driver_unregister(&qcom_cpufreq_kryo_driver);
-}
-module_exit(qcom_cpufreq_kryo_exit);
-
-MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Kryo CPUfreq driver");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/cpufreq/qcom-cpufreq-nvmem.c b/drivers/cpufreq/qcom-cpufreq-nvmem.c
new file mode 100644
index 000000000000..f0d2d5035413
--- /dev/null
+++ b/drivers/cpufreq/qcom-cpufreq-nvmem.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+/*
+ * In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO processors,
+ * the CPU frequency subset and voltage value of each OPP varies
+ * based on the silicon variant in use. Qualcomm Process Voltage Scaling Tables
+ * defines the voltage and frequency value based on the msm-id in SMEM
+ * and speedbin blown in the efuse combination.
+ * The qcom-cpufreq-nvmem driver reads the msm-id and efuse value from the SoC
+ * to provide the OPP framework with required information.
+ * This is used to determine the voltage and frequency value for each OPP of
+ * operating-points-v2 table when it is parsed by the OPP framework.
+ */
+
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/smem.h>
+
+#define MSM_ID_SMEM	137
+
+enum _msm_id {
+	MSM8996V3 = 0xF6ul,
+	APQ8096V3 = 0x123ul,
+	MSM8996SG = 0x131ul,
+	APQ8096SG = 0x138ul,
+};
+
+enum _msm8996_version {
+	MSM8996_V3,
+	MSM8996_SG,
+	NUM_OF_MSM8996_VERSIONS,
+};
+
+struct qcom_cpufreq_drv;
+
+struct qcom_cpufreq_match_data {
+	int (*get_version)(struct device *cpu_dev,
+			   struct nvmem_cell *speedbin_nvmem,
+			   struct qcom_cpufreq_drv *drv);
+	const char **genpd_names;
+};
+
+struct qcom_cpufreq_drv {
+	struct opp_table **opp_tables;
+	struct opp_table **genpd_opp_tables;
+	u32 versions;
+	const struct qcom_cpufreq_match_data *data;
+};
+
+static struct platform_device *cpufreq_dt_pdev, *cpufreq_pdev;
+
+static enum _msm8996_version qcom_cpufreq_get_msm_id(void)
+{
+	size_t len;
+	u32 *msm_id;
+	enum _msm8996_version version;
+
+	msm_id = qcom_smem_get(QCOM_SMEM_HOST_ANY, MSM_ID_SMEM, &len);
+	if (IS_ERR(msm_id))
+		return NUM_OF_MSM8996_VERSIONS;
+
+	/* The first 4 bytes are format, next to them is the actual msm-id */
+	msm_id++;
+
+	switch ((enum _msm_id)*msm_id) {
+	case MSM8996V3:
+	case APQ8096V3:
+		version = MSM8996_V3;
+		break;
+	case MSM8996SG:
+	case APQ8096SG:
+		version = MSM8996_SG;
+		break;
+	default:
+		version = NUM_OF_MSM8996_VERSIONS;
+	}
+
+	return version;
+}
+
+static int qcom_cpufreq_kryo_name_version(struct device *cpu_dev,
+					  struct nvmem_cell *speedbin_nvmem,
+					  struct qcom_cpufreq_drv *drv)
+{
+	size_t len;
+	u8 *speedbin;
+	enum _msm8996_version msm8996_version;
+
+	msm8996_version = qcom_cpufreq_get_msm_id();
+	if (NUM_OF_MSM8996_VERSIONS == msm8996_version) {
+		dev_err(cpu_dev, "Not Snapdragon 820/821!");
+		return -ENODEV;
+	}
+
+	speedbin = nvmem_cell_read(speedbin_nvmem, &len);
+	if (IS_ERR(speedbin))
+		return PTR_ERR(speedbin);
+
+	switch (msm8996_version) {
+	case MSM8996_V3:
+		drv->versions = 1 << (unsigned int)(*speedbin);
+		break;
+	case MSM8996_SG:
+		drv->versions = 1 << ((unsigned int)(*speedbin) + 4);
+		break;
+	default:
+		BUG();
+		break;
+	}
+
+	kfree(speedbin);
+	return 0;
+}
+
+static const struct qcom_cpufreq_match_data match_data_kryo = {
+	.get_version = qcom_cpufreq_kryo_name_version,
+};
+
+static const char *qcs404_genpd_names[] = { "cpr", NULL };
+
+static const struct qcom_cpufreq_match_data match_data_qcs404 = {
+	.genpd_names = qcs404_genpd_names,
+};
+
+static int qcom_cpufreq_probe(struct platform_device *pdev)
+{
+	struct qcom_cpufreq_drv *drv;
+	struct nvmem_cell *speedbin_nvmem;
+	struct device_node *np;
+	struct device *cpu_dev;
+	unsigned cpu;
+	const struct of_device_id *match;
+	int ret;
+
+	cpu_dev = get_cpu_device(0);
+	if (!cpu_dev)
+		return -ENODEV;
+
+	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
+	if (!np)
+		return -ENOENT;
+
+	ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
+	if (!ret) {
+		of_node_put(np);
+		return -ENOENT;
+	}
+
+	drv = kzalloc(sizeof(*drv), GFP_KERNEL);
+	if (!drv)
+		return -ENOMEM;
+
+	match = pdev->dev.platform_data;
+	drv->data = match->data;
+	if (!drv->data) {
+		ret = -ENODEV;
+		goto free_drv;
+	}
+
+	if (drv->data->get_version) {
+		speedbin_nvmem = of_nvmem_cell_get(np, NULL);
+		if (IS_ERR(speedbin_nvmem)) {
+			if (PTR_ERR(speedbin_nvmem) != -EPROBE_DEFER)
+				dev_err(cpu_dev,
+					"Could not get nvmem cell: %ld\n",
+					PTR_ERR(speedbin_nvmem));
+			ret = PTR_ERR(speedbin_nvmem);
+			goto free_drv;
+		}
+
+		ret = drv->data->get_version(cpu_dev, speedbin_nvmem, drv);
+		if (ret) {
+			nvmem_cell_put(speedbin_nvmem);
+			goto free_drv;
+		}
+		nvmem_cell_put(speedbin_nvmem);
+	}
+	of_node_put(np);
+
+	drv->opp_tables = kcalloc(num_possible_cpus(), sizeof(*drv->opp_tables),
+				  GFP_KERNEL);
+	if (!drv->opp_tables) {
+		ret = -ENOMEM;
+		goto free_drv;
+	}
+
+	drv->genpd_opp_tables = kcalloc(num_possible_cpus(),
+					sizeof(*drv->genpd_opp_tables),
+					GFP_KERNEL);
+	if (!drv->genpd_opp_tables) {
+		ret = -ENOMEM;
+		goto free_opp;
+	}
+
+	for_each_possible_cpu(cpu) {
+		cpu_dev = get_cpu_device(cpu);
+		if (NULL == cpu_dev) {
+			ret = -ENODEV;
+			goto free_genpd_opp;
+		}
+
+		if (drv->data->get_version) {
+			drv->opp_tables[cpu] =
+				dev_pm_opp_set_supported_hw(cpu_dev,
+							    &drv->versions, 1);
+			if (IS_ERR(drv->opp_tables[cpu])) {
+				ret = PTR_ERR(drv->opp_tables[cpu]);
+				dev_err(cpu_dev,
+					"Failed to set supported hardware\n");
+				goto free_genpd_opp;
+			}
+		}
+
+		if (drv->data->genpd_names) {
+			drv->genpd_opp_tables[cpu] =
+				dev_pm_opp_attach_genpd(cpu_dev,
+							drv->data->genpd_names,
+							NULL);
+			if (IS_ERR(drv->genpd_opp_tables[cpu])) {
+				ret = PTR_ERR(drv->genpd_opp_tables[cpu]);
+				if (ret != -EPROBE_DEFER)
+					dev_err(cpu_dev,
+						"Could not attach to pm_domain: %d\n",
+						ret);
+				goto free_genpd_opp;
+			}
+		}
+	}
+
+	cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
+							  NULL, 0);
+	if (!IS_ERR(cpufreq_dt_pdev)) {
+		platform_set_drvdata(pdev, drv);
+		return 0;
+	}
+
+	ret = PTR_ERR(cpufreq_dt_pdev);
+	dev_err(cpu_dev, "Failed to register platform device\n");
+
+free_genpd_opp:
+	for_each_possible_cpu(cpu) {
+		if (IS_ERR_OR_NULL(drv->genpd_opp_tables[cpu]))
+			break;
+		dev_pm_opp_detach_genpd(drv->genpd_opp_tables[cpu]);
+	}
+	kfree(drv->genpd_opp_tables);
+free_opp:
+	for_each_possible_cpu(cpu) {
+		if (IS_ERR_OR_NULL(drv->opp_tables[cpu]))
+			break;
+		dev_pm_opp_put_supported_hw(drv->opp_tables[cpu]);
+	}
+	kfree(drv->opp_tables);
+free_drv:
+	kfree(drv);
+
+	return ret;
+}
+
+static int qcom_cpufreq_remove(struct platform_device *pdev)
+{
+	struct qcom_cpufreq_drv *drv = platform_get_drvdata(pdev);
+	unsigned int cpu;
+
+	platform_device_unregister(cpufreq_dt_pdev);
+
+	for_each_possible_cpu(cpu) {
+		if (drv->opp_tables[cpu])
+			dev_pm_opp_put_supported_hw(drv->opp_tables[cpu]);
+		if (drv->genpd_opp_tables[cpu])
+			dev_pm_opp_detach_genpd(drv->genpd_opp_tables[cpu]);
+	}
+
+	kfree(drv->opp_tables);
+	kfree(drv->genpd_opp_tables);
+	kfree(drv);
+
+	return 0;
+}
+
+static struct platform_driver qcom_cpufreq_driver = {
+	.probe = qcom_cpufreq_probe,
+	.remove = qcom_cpufreq_remove,
+	.driver = {
+		.name = "qcom-cpufreq-nvmem",
+	},
+};
+
+static const struct of_device_id qcom_cpufreq_match_list[] __initconst = {
+	{ .compatible = "qcom,apq8096", .data = &match_data_kryo },
+	{ .compatible = "qcom,msm8996", .data = &match_data_kryo },
+	{ .compatible = "qcom,qcs404", .data = &match_data_qcs404 },
+	{},
+};
+
+/*
+ * Since the driver depends on smem and nvmem drivers, which may
+ * return EPROBE_DEFER, all the real activity is done in the probe,
+ * which may be defered as well. The init here is only registering
+ * the driver and the platform device.
+ */
+static int __init qcom_cpufreq_init(void)
+{
+	struct device_node *np = of_find_node_by_path("/");
+	const struct of_device_id *match;
+	int ret;
+
+	if (!np)
+		return -ENODEV;
+
+	match = of_match_node(qcom_cpufreq_match_list, np);
+	of_node_put(np);
+	if (!match)
+		return -ENODEV;
+
+	ret = platform_driver_register(&qcom_cpufreq_driver);
+	if (unlikely(ret < 0))
+		return ret;
+
+	cpufreq_pdev = platform_device_register_data(NULL, "qcom-cpufreq-nvmem",
+						     -1, match, sizeof(*match));
+	ret = PTR_ERR_OR_ZERO(cpufreq_pdev);
+	if (0 == ret)
+		return 0;
+
+	platform_driver_unregister(&qcom_cpufreq_driver);
+	return ret;
+}
+module_init(qcom_cpufreq_init);
+
+static void __exit qcom_cpufreq_exit(void)
+{
+	platform_device_unregister(cpufreq_pdev);
+	platform_driver_unregister(&qcom_cpufreq_driver);
+}
+module_exit(qcom_cpufreq_exit);
+
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. CPUfreq driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index c094d5d20fd7..0ee8c0133d3e 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -401,6 +401,54 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
 
+/**
+ * dev_pm_opp_find_level_exact() - search for an exact level
+ * @dev:		device for which we do this operation
+ * @level:		level to search for
+ *
+ * Return: Searches for exact match in the opp table and returns pointer to the
+ * matching opp if found, else returns ERR_PTR in case of error and should
+ * be handled using IS_ERR. Error return values can be:
+ * EINVAL:	for bad pointer
+ * ERANGE:	no match found for search
+ * ENODEV:	if device not found in list of registered devices
+ *
+ * The callers are required to call dev_pm_opp_put() for the returned OPP after
+ * use.
+ */
+struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev,
+					       unsigned int level)
+{
+	struct opp_table *opp_table;
+	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table)) {
+		int r = PTR_ERR(opp_table);
+
+		dev_err(dev, "%s: OPP table not found (%d)\n", __func__, r);
+		return ERR_PTR(r);
+	}
+
+	mutex_lock(&opp_table->lock);
+
+	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
+		if (temp_opp->level == level) {
+			opp = temp_opp;
+
+			/* Increment the reference count of OPP */
+			dev_pm_opp_get(opp);
+			break;
+		}
+	}
+
+	mutex_unlock(&opp_table->lock);
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return opp;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_exact);
+
 static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
 						   unsigned long *freq)
 {
@@ -1771,6 +1819,7 @@ static void _opp_detach_genpd(struct opp_table *opp_table)
  * dev_pm_opp_attach_genpd - Attach genpd(s) for the device and save virtual device pointer
  * @dev: Consumer device for which the genpd is getting attached.
  * @names: Null terminated array of pointers containing names of genpd to attach.
+ * @virt_devs: Pointer to return the array of virtual devices.
  *
  * Multiple generic power domains for a device are supported with the help of
  * virtual genpd devices, which are created for each consumer device - genpd
@@ -1784,12 +1833,16 @@ static void _opp_detach_genpd(struct opp_table *opp_table)
  *
  * This helper needs to be called once with a list of all genpd to attach.
  * Otherwise the original device structure will be used instead by the OPP core.
+ *
+ * The order of entries in the names array must match the order in which
+ * "required-opps" are added in DT.
  */
-struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names)
+struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,
+		const char **names, struct device ***virt_devs)
 {
 	struct opp_table *opp_table;
 	struct device *virt_dev;
-	int index, ret = -EINVAL;
+	int index = 0, ret = -EINVAL;
 	const char **name = names;
 
 	opp_table = dev_pm_opp_get_opp_table(dev);
@@ -1815,14 +1868,6 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names
 		goto unlock;
 
 	while (*name) {
-		index = of_property_match_string(dev->of_node,
-						 "power-domain-names", *name);
-		if (index < 0) {
-			dev_err(dev, "Failed to find power domain: %s (%d)\n",
-				*name, index);
-			goto err;
-		}
-
 		if (index >= opp_table->required_opp_count) {
 			dev_err(dev, "Index can't be greater than required-opp-count - 1, %s (%d : %d)\n",
 				*name, opp_table->required_opp_count, index);
@@ -1843,9 +1888,12 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names
 		}
 
 		opp_table->genpd_virt_devs[index] = virt_dev;
+		index++;
 		name++;
 	}
 
+	if (virt_devs)
+		*virt_devs = opp_table->genpd_virt_devs;
 	mutex_unlock(&opp_table->genpd_virt_dev_lock);
 
 	return opp_table;