1 files changed, 352 insertions, 0 deletions
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");