--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016-2017 Texas Instruments Incorporated - http://www.ti.com/
+ * Nishanth Menon <nm@ti.com>
+ * Dave Gerlach <d-gerlach@ti.com>
+ *
+ * TI OPP supply driver that provides override into the regulator control
+ * for generic opp core to handle devices with ABB regulator and/or
+ * SmartReflex Class0.
+ */
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+/**
+ * struct ti_opp_supply_optimum_voltage_table - optimized voltage table
+ * @reference_uv: reference voltage (usually Nominal voltage)
+ * @optimized_uv: Optimized voltage from efuse
+ */
+struct ti_opp_supply_optimum_voltage_table {
+ unsigned int reference_uv;
+ unsigned int optimized_uv;
+};
+
+/**
+ * struct ti_opp_supply_data - OMAP specific opp supply data
+ * @vdd_table: Optimized voltage mapping table
+ * @num_vdd_table: number of entries in vdd_table
+ * @vdd_absolute_max_voltage_uv: absolute maximum voltage in UV for the supply
+ */
+struct ti_opp_supply_data {
+ struct ti_opp_supply_optimum_voltage_table *vdd_table;
+ u32 num_vdd_table;
+ u32 vdd_absolute_max_voltage_uv;
+};
+
+static struct ti_opp_supply_data opp_data;
+
+/**
+ * struct ti_opp_supply_of_data - device tree match data
+ * @flags: specific type of opp supply
+ * @efuse_voltage_mask: mask required for efuse register representing voltage
+ * @efuse_voltage_uv: Are the efuse entries in micro-volts? if not, assume
+ * milli-volts.
+ */
+struct ti_opp_supply_of_data {
+#define OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE BIT(1)
+#define OPPDM_HAS_NO_ABB BIT(2)
+ const u8 flags;
+ const u32 efuse_voltage_mask;
+ const bool efuse_voltage_uv;
+};
+
+/**
+ * _store_optimized_voltages() - store optimized voltages
+ * @dev: ti opp supply device for which we need to store info
+ * @data: data specific to the device
+ *
+ * Picks up efuse based optimized voltages for VDD unique per device and
+ * stores it in internal data structure for use during transition requests.
+ *
+ * Return: If successful, 0, else appropriate error value.
+ */
+static int _store_optimized_voltages(struct device *dev,
+ struct ti_opp_supply_data *data)
+{
+ void __iomem *base;
+ struct property *prop;
+ struct resource *res;
+ const __be32 *val;
+ int proplen, i;
+ int ret = 0;
+ struct ti_opp_supply_optimum_voltage_table *table;
+ const struct ti_opp_supply_of_data *of_data = dev_get_drvdata(dev);
+
+ /* pick up Efuse based voltages */
+ res = platform_get_resource(to_platform_device(dev), IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "Unable to get IO resource\n");
+ ret = -ENODEV;
+ goto out_map;
+ }
+
+ base = ioremap_nocache(res->start, resource_size(res));
+ if (!base) {
+ dev_err(dev, "Unable to map Efuse registers\n");
+ ret = -ENOMEM;
+ goto out_map;
+ }
+
+ /* Fetch efuse-settings. */
+ prop = of_find_property(dev->of_node, "ti,efuse-settings", NULL);
+ if (!prop) {
+ dev_err(dev, "No 'ti,efuse-settings' property found\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ proplen = prop->length / sizeof(int);
+ data->num_vdd_table = proplen / 2;
+ /* Verify for corrupted OPP entries in dt */
+ if (data->num_vdd_table * 2 * sizeof(int) != prop->length) {
+ dev_err(dev, "Invalid 'ti,efuse-settings'\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = of_property_read_u32(dev->of_node, "ti,absolute-max-voltage-uv",
+ &data->vdd_absolute_max_voltage_uv);
+ if (ret) {
+ dev_err(dev, "ti,absolute-max-voltage-uv is missing\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ table = kzalloc(sizeof(*data->vdd_table) *
+ data->num_vdd_table, GFP_KERNEL);
+ if (!table) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ data->vdd_table = table;
+
+ val = prop->value;
+ for (i = 0; i < data->num_vdd_table; i++, table++) {
+ u32 efuse_offset;
+ u32 tmp;
+
+ table->reference_uv = be32_to_cpup(val++);
+ efuse_offset = be32_to_cpup(val++);
+
+ tmp = readl(base + efuse_offset);
+ tmp &= of_data->efuse_voltage_mask;
+ tmp >>= __ffs(of_data->efuse_voltage_mask);
+
+ table->optimized_uv = of_data->efuse_voltage_uv ? tmp :
+ tmp * 1000;
+
+ dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d vset=%d\n",
+ i, efuse_offset, table->reference_uv,
+ table->optimized_uv);
+
+ /*
+ * Some older samples might not have optimized efuse
+ * Use reference voltage for those - just add debug message
+ * for them.
+ */
+ if (!table->optimized_uv) {
+ dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d:vset0\n",
+ i, efuse_offset, table->reference_uv);
+ table->optimized_uv = table->reference_uv;
+ }
+ }
+out:
+ iounmap(base);
+out_map:
+ return ret;
+}
+
+/**
+ * _free_optimized_voltages() - free resources for optvoltages
+ * @dev: device for which we need to free info
+ * @data: data specific to the device
+ */
+static void _free_optimized_voltages(struct device *dev,
+ struct ti_opp_supply_data *data)
+{
+ kfree(data->vdd_table);
+ data->vdd_table = NULL;
+ data->num_vdd_table = 0;
+}
+
+/**
+ * _get_optimal_vdd_voltage() - Finds optimal voltage for the supply
+ * @dev: device for which we need to find info
+ * @data: data specific to the device
+ * @reference_uv: reference voltage (OPP voltage) for which we need value
+ *
+ * Return: if a match is found, return optimized voltage, else return
+ * reference_uv, also return reference_uv if no optimization is needed.
+ */
+static int _get_optimal_vdd_voltage(struct device *dev,
+ struct ti_opp_supply_data *data,
+ int reference_uv)
+{
+ int i;
+ struct ti_opp_supply_optimum_voltage_table *table;
+
+ if (!data->num_vdd_table)
+ return reference_uv;
+
+ table = data->vdd_table;
+ if (!table)
+ return -EINVAL;
+
+ /* Find a exact match - this list is usually very small */
+ for (i = 0; i < data->num_vdd_table; i++, table++)
+ if (table->reference_uv == reference_uv)
+ return table->optimized_uv;
+
+ /* IF things are screwed up, we'd make a mess on console.. ratelimit */
+ dev_err_ratelimited(dev, "%s: Failed optimized voltage match for %d\n",
+ __func__, reference_uv);
+ return reference_uv;
+}
+
+static int _opp_set_voltage(struct device *dev,
+ struct dev_pm_opp_supply *supply,
+ int new_target_uv, struct regulator *reg,
+ char *reg_name)
+{
+ int ret;
+ unsigned long vdd_uv, uv_max;
+
+ if (new_target_uv)
+ vdd_uv = new_target_uv;
+ else
+ vdd_uv = supply->u_volt;
+
+ /*
+ * If we do have an absolute max voltage specified, then we should
+ * use that voltage instead to allow for cases where the voltage rails
+ * are ganged (example if we set the max for an opp as 1.12v, and
+ * the absolute max is 1.5v, for another rail to get 1.25v, it cannot
+ * be achieved if the regulator is constrainted to max of 1.12v, even
+ * if it can function at 1.25v
+ */
+ if (opp_data.vdd_absolute_max_voltage_uv)
+ uv_max = opp_data.vdd_absolute_max_voltage_uv;
+ else
+ uv_max = supply->u_volt_max;
+
+ if (vdd_uv > uv_max ||
+ vdd_uv < supply->u_volt_min ||
+ supply->u_volt_min > uv_max) {
+ dev_warn(dev,
+ "Invalid range voltages [Min:%lu target:%lu Max:%lu]\n",
+ supply->u_volt_min, vdd_uv, uv_max);
+ return -EINVAL;
+ }
+
+ dev_dbg(dev, "%s scaling to %luuV[min %luuV max %luuV]\n", reg_name,
+ vdd_uv, supply->u_volt_min,
+ uv_max);
+
+ ret = regulator_set_voltage_triplet(reg,
+ supply->u_volt_min,
+ vdd_uv,
+ uv_max);
+ if (ret) {
+ dev_err(dev, "%s failed for %luuV[min %luuV max %luuV]\n",
+ reg_name, vdd_uv, supply->u_volt_min,
+ uv_max);
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * ti_opp_supply_set_opp() - do the opp supply transition
+ * @data: information on regulators and new and old opps provided by
+ * opp core to use in transition
+ *
+ * Return: If successful, 0, else appropriate error value.
+ */
+int ti_opp_supply_set_opp(struct dev_pm_set_opp_data *data)
+{
+ struct dev_pm_opp_supply *old_supply_vdd = &data->old_opp.supplies[0];
+ struct dev_pm_opp_supply *old_supply_vbb = &data->old_opp.supplies[1];
+ struct dev_pm_opp_supply *new_supply_vdd = &data->new_opp.supplies[0];
+ struct dev_pm_opp_supply *new_supply_vbb = &data->new_opp.supplies[1];
+ struct device *dev = data->dev;
+ unsigned long old_freq = data->old_opp.rate, freq = data->new_opp.rate;
+ struct clk *clk = data->clk;
+ struct regulator *vdd_reg = data->regulators[0];
+ struct regulator *vbb_reg = data->regulators[1];
+ int vdd_uv;
+ int ret;
+
+ vdd_uv = _get_optimal_vdd_voltage(dev, &opp_data,
+ new_supply_vbb->u_volt);
+
+ /* Scaling up? Scale voltage before frequency */
+ if (freq > old_freq) {
+ ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
+ "vdd");
+ if (ret)
+ goto restore_voltage;
+
+ ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
+ if (ret)
+ goto restore_voltage;
+ }
+
+ /* Change frequency */
+ dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n",
+ __func__, old_freq, freq);
+
+ ret = clk_set_rate(clk, freq);
+ if (ret) {
+ dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
+ ret);
+ goto restore_voltage;
+ }
+
+ /* Scaling down? Scale voltage after frequency */
+ if (freq < old_freq) {
+ ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
+ if (ret)
+ goto restore_freq;
+
+ ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
+ "vdd");
+ if (ret)
+ goto restore_freq;
+ }
+
+ return 0;
+
+restore_freq:
+ ret = clk_set_rate(clk, old_freq);
+ if (ret)
+ dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
+ __func__, old_freq);
+restore_voltage:
+ /* This shouldn't harm even if the voltages weren't updated earlier */
+ if (old_supply_vdd->u_volt) {
+ ret = _opp_set_voltage(dev, old_supply_vbb, 0, vbb_reg, "vbb");
+ if (ret)
+ return ret;
+
+ ret = _opp_set_voltage(dev, old_supply_vdd, 0, vdd_reg,
+ "vdd");
+ if (ret)
+ return ret;
+ }
+
+ return ret;
+}
+
+static const struct ti_opp_supply_of_data omap_generic_of_data = {
+};
+
+static const struct ti_opp_supply_of_data omap_omap5_of_data = {
+ .flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE,
+ .efuse_voltage_mask = 0xFFF,
+ .efuse_voltage_uv = false,
+};
+
+static const struct ti_opp_supply_of_data omap_omap5core_of_data = {
+ .flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE | OPPDM_HAS_NO_ABB,
+ .efuse_voltage_mask = 0xFFF,
+ .efuse_voltage_uv = false,
+};
+
+static const struct of_device_id ti_opp_supply_of_match[] = {
+ {.compatible = "ti,omap-opp-supply", .data = &omap_generic_of_data},
+ {.compatible = "ti,omap5-opp-supply", .data = &omap_omap5_of_data},
+ {.compatible = "ti,omap5-core-opp-supply",
+ .data = &omap_omap5core_of_data},
+ {},
+};
+MODULE_DEVICE_TABLE(of, ti_opp_supply_of_match);
+
+static int ti_opp_supply_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device *cpu_dev = get_cpu_device(0);
+ const struct of_device_id *match;
+ const struct ti_opp_supply_of_data *of_data;
+ int ret = 0;
+
+ match = of_match_device(ti_opp_supply_of_match, dev);
+ if (!match) {
+ /* We do not expect this to happen */
+ dev_err(dev, "%s: Unable to match device\n", __func__);
+ return -ENODEV;
+ }
+ if (!match->data) {
+ /* Again, unlikely.. but mistakes do happen */
+ dev_err(dev, "%s: Bad data in match\n", __func__);
+ return -EINVAL;
+ }
+ of_data = match->data;
+
+ dev_set_drvdata(dev, (void *)of_data);
+
+ /* If we need optimized voltage */
+ if (of_data->flags & OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE) {
+ ret = _store_optimized_voltages(dev, &opp_data);
+ if (ret)
+ return ret;
+ }
+
+ ret = PTR_ERR_OR_ZERO(dev_pm_opp_register_set_opp_helper(cpu_dev,
+ ti_opp_supply_set_opp));
+ if (ret)
+ _free_optimized_voltages(dev, &opp_data);
+
+ return ret;
+}
+
+static struct platform_driver ti_opp_supply_driver = {
+ .probe = ti_opp_supply_probe,
+ .driver = {
+ .name = "ti_opp_supply",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(ti_opp_supply_of_match),
+ },
+};
+module_platform_driver(ti_opp_supply_driver);
+
+MODULE_DESCRIPTION("Texas Instruments OMAP OPP Supply driver");
+MODULE_AUTHOR("Texas Instruments Inc.");
+MODULE_LICENSE("GPL v2");
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