diff options
Diffstat (limited to 'drivers/opp/ti-opp-supply.c')
| -rw-r--r-- | drivers/opp/ti-opp-supply.c | 425 |
1 files changed, 425 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..370eff3acd8a --- /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. + */ +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"); |