VisionFive2 Linux kernel

StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)

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author: Dave Gerlach <d-gerlach@ti.com> 2017-12-14 22:25:28 -0600 committer: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 2017-12-17 19:17:44 +0100 commit: 9a835fa6e47f27b1ae71390b6f12efce7335aaac parent: 212b7287ae6098337fffa9c0cd7e139dceb98125
Commit Summary:
PM / OPP: Add ti-opp-supply driver
Diffstat:
1 file changed, 371 insertions, 0 deletions
diff --git a/drivers/opp/ti-opp-supply.c b/drivers/opp/ti-opp-supply.c
new file mode 100644
index 000000000000..44dae3e51aac
--- /dev/null
+++ b/drivers/opp/ti-opp-supply.c
@@ -0,0 +1,425 @@
+// 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");