// 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.
*/
static 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");
