--- /dev/null
+/*
+ * TI CPUFreq/OPP hw-supported driver
+ *
+ * Copyright (C) 2016-2017 Texas Instruments, Inc.
+ * Dave Gerlach <d-gerlach@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/cpu.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/pm_opp.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define REVISION_MASK 0xF
+#define REVISION_SHIFT 28
+
+#define AM33XX_800M_ARM_MPU_MAX_FREQ 0x1E2F
+#define AM43XX_600M_ARM_MPU_MAX_FREQ 0xFFA
+
+#define DRA7_EFUSE_HAS_OD_MPU_OPP 11
+#define DRA7_EFUSE_HAS_HIGH_MPU_OPP 15
+#define DRA7_EFUSE_HAS_ALL_MPU_OPP 23
+
+#define DRA7_EFUSE_NOM_MPU_OPP BIT(0)
+#define DRA7_EFUSE_OD_MPU_OPP BIT(1)
+#define DRA7_EFUSE_HIGH_MPU_OPP BIT(2)
+
+#define VERSION_COUNT 2
+
+struct ti_cpufreq_data;
+
+struct ti_cpufreq_soc_data {
+ unsigned long (*efuse_xlate)(struct ti_cpufreq_data *opp_data,
+ unsigned long efuse);
+ unsigned long efuse_fallback;
+ unsigned long efuse_offset;
+ unsigned long efuse_mask;
+ unsigned long efuse_shift;
+ unsigned long rev_offset;
+};
+
+struct ti_cpufreq_data {
+ struct device *cpu_dev;
+ struct device_node *opp_node;
+ struct regmap *syscon;
+ const struct ti_cpufreq_soc_data *soc_data;
+};
+
+static unsigned long amx3_efuse_xlate(struct ti_cpufreq_data *opp_data,
+ unsigned long efuse)
+{
+ if (!efuse)
+ efuse = opp_data->soc_data->efuse_fallback;
+ /* AM335x and AM437x use "OPP disable" bits, so invert */
+ return ~efuse;
+}
+
+static unsigned long dra7_efuse_xlate(struct ti_cpufreq_data *opp_data,
+ unsigned long efuse)
+{
+ unsigned long calculated_efuse = DRA7_EFUSE_NOM_MPU_OPP;
+
+ /*
+ * The efuse on dra7 and am57 parts contains a specific
+ * value indicating the highest available OPP.
+ */
+
+ switch (efuse) {
+ case DRA7_EFUSE_HAS_ALL_MPU_OPP:
+ case DRA7_EFUSE_HAS_HIGH_MPU_OPP:
+ calculated_efuse |= DRA7_EFUSE_HIGH_MPU_OPP;
+ case DRA7_EFUSE_HAS_OD_MPU_OPP:
+ calculated_efuse |= DRA7_EFUSE_OD_MPU_OPP;
+ }
+
+ return calculated_efuse;
+}
+
+static struct ti_cpufreq_soc_data am3x_soc_data = {
+ .efuse_xlate = amx3_efuse_xlate,
+ .efuse_fallback = AM33XX_800M_ARM_MPU_MAX_FREQ,
+ .efuse_offset = 0x07fc,
+ .efuse_mask = 0x1fff,
+ .rev_offset = 0x600,
+};
+
+static struct ti_cpufreq_soc_data am4x_soc_data = {
+ .efuse_xlate = amx3_efuse_xlate,
+ .efuse_fallback = AM43XX_600M_ARM_MPU_MAX_FREQ,
+ .efuse_offset = 0x0610,
+ .efuse_mask = 0x3f,
+ .rev_offset = 0x600,
+};
+
+static struct ti_cpufreq_soc_data dra7_soc_data = {
+ .efuse_xlate = dra7_efuse_xlate,
+ .efuse_offset = 0x020c,
+ .efuse_mask = 0xf80000,
+ .efuse_shift = 19,
+ .rev_offset = 0x204,
+};
+
+/**
+ * ti_cpufreq_get_efuse() - Parse and return efuse value present on SoC
+ * @opp_data: pointer to ti_cpufreq_data context
+ * @efuse_value: Set to the value parsed from efuse
+ *
+ * Returns error code if efuse not read properly.
+ */
+static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data,
+ u32 *efuse_value)
+{
+ struct device *dev = opp_data->cpu_dev;
+ u32 efuse;
+ int ret;
+
+ ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset,
+ &efuse);
+ if (ret) {
+ dev_err(dev,
+ "Failed to read the efuse value from syscon: %d\n",
+ ret);
+ return ret;
+ }
+
+ efuse = (efuse & opp_data->soc_data->efuse_mask);
+ efuse >>= opp_data->soc_data->efuse_shift;
+
+ *efuse_value = opp_data->soc_data->efuse_xlate(opp_data, efuse);
+
+ return 0;
+}
+
+/**
+ * ti_cpufreq_get_rev() - Parse and return rev value present on SoC
+ * @opp_data: pointer to ti_cpufreq_data context
+ * @revision_value: Set to the value parsed from revision register
+ *
+ * Returns error code if revision not read properly.
+ */
+static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data,
+ u32 *revision_value)
+{
+ struct device *dev = opp_data->cpu_dev;
+ u32 revision;
+ int ret;
+
+ ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset,
+ &revision);
+ if (ret) {
+ dev_err(dev,
+ "Failed to read the revision number from syscon: %d\n",
+ ret);
+ return ret;
+ }
+
+ *revision_value = BIT((revision >> REVISION_SHIFT) & REVISION_MASK);
+
+ return 0;
+}
+
+static int ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data *opp_data)
+{
+ struct device *dev = opp_data->cpu_dev;
+ struct device_node *np = opp_data->opp_node;
+
+ opp_data->syscon = syscon_regmap_lookup_by_phandle(np,
+ "syscon");
+ if (IS_ERR(opp_data->syscon)) {
+ dev_err(dev,
+ "\"syscon\" is missing, cannot use OPPv2 table.\n");
+ return PTR_ERR(opp_data->syscon);
+ }
+
+ return 0;
+}
+
+static const struct of_device_id ti_cpufreq_of_match[] = {
+ { .compatible = "ti,am33xx", .data = &am3x_soc_data, },
+ { .compatible = "ti,am4372", .data = &am4x_soc_data, },
+ { .compatible = "ti,dra7", .data = &dra7_soc_data },
+ {},
+};
+
+static int ti_cpufreq_init(void)
+{
+ u32 version[VERSION_COUNT];
+ struct device_node *np;
+ const struct of_device_id *match;
+ struct ti_cpufreq_data *opp_data;
+ int ret;
+
+ np = of_find_node_by_path("/");
+ match = of_match_node(ti_cpufreq_of_match, np);
+ if (!match)
+ return -ENODEV;
+
+ opp_data = kzalloc(sizeof(*opp_data), GFP_KERNEL);
+ if (!opp_data)
+ return -ENOMEM;
+
+ opp_data->soc_data = match->data;
+
+ opp_data->cpu_dev = get_cpu_device(0);
+ if (!opp_data->cpu_dev) {
+ pr_err("%s: Failed to get device for CPU0\n", __func__);
+ return -ENODEV;
+ }
+
+ opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
+ if (!opp_data->opp_node) {
+ dev_info(opp_data->cpu_dev,
+ "OPP-v2 not supported, cpufreq-dt will attempt to use legacy tables.\n");
+ goto register_cpufreq_dt;
+ }
+
+ ret = ti_cpufreq_setup_syscon_register(opp_data);
+ if (ret)
+ goto fail_put_node;
+
+ /*
+ * OPPs determine whether or not they are supported based on
+ * two metrics:
+ * 0 - SoC Revision
+ * 1 - eFuse value
+ */
+ ret = ti_cpufreq_get_rev(opp_data, &version[0]);
+ if (ret)
+ goto fail_put_node;
+
+ ret = ti_cpufreq_get_efuse(opp_data, &version[1]);
+ if (ret)
+ goto fail_put_node;
+
+ of_node_put(opp_data->opp_node);
+
+ ret = PTR_ERR_OR_ZERO(dev_pm_opp_set_supported_hw(opp_data->cpu_dev,
+ version, VERSION_COUNT));
+ if (ret) {
+ dev_err(opp_data->cpu_dev,
+ "Failed to set supported hardware\n");
+ goto fail_put_node;
+ }
+
+register_cpufreq_dt:
+ platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
+
+ return 0;
+
+fail_put_node:
+ of_node_put(opp_data->opp_node);
+
+ return ret;
+}
+module_init(ti_cpufreq_init);
+
+MODULE_DESCRIPTION("TI CPUFreq/OPP hw-supported driver");
+MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
+MODULE_LICENSE("GPL v2");
projects / openwrt / staging / blogic.git / commitdiff