PM / OPP: Add ti-opp-supply driver

obj-y				+= core.o cpu.o

obj-$(CONFIG_OF)		+= of.o

obj-$(CONFIG_DEBUG_FS)		+= debugfs.o

obj-$(CONFIG_ARM_TI_CPUFREQ)	+= ti-opp-supply.o

// 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");