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Diffstat (limited to 'arch/arm/mach-omap2/voltage.c')
-rw-r--r-- | arch/arm/mach-omap2/voltage.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c new file mode 100644 index 0000000000..49e8bc69ab --- /dev/null +++ b/arch/arm/mach-omap2/voltage.c @@ -0,0 +1,339 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * OMAP3/OMAP4 Voltage Management Routines + * + * Author: Thara Gopinath <thara@ti.com> + * + * Copyright (C) 2007 Texas Instruments, Inc. + * Rajendra Nayak <rnayak@ti.com> + * Lesly A M <x0080970@ti.com> + * + * Copyright (C) 2008, 2011 Nokia Corporation + * Kalle Jokiniemi + * Paul Walmsley + * + * Copyright (C) 2010 Texas Instruments, Inc. + * Thara Gopinath <thara@ti.com> + */ + +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/debugfs.h> +#include <linux/slab.h> +#include <linux/clk.h> + +#include "common.h" + +#include "prm-regbits-34xx.h" +#include "prm-regbits-44xx.h" +#include "prm44xx.h" +#include "prcm44xx.h" +#include "prminst44xx.h" +#include "control.h" + +#include "voltage.h" +#include "powerdomain.h" + +#include "vc.h" +#include "vp.h" + +static LIST_HEAD(voltdm_list); + +/* Public functions */ +/** + * voltdm_get_voltage() - Gets the current non-auto-compensated voltage + * @voltdm: pointer to the voltdm for which current voltage info is needed + * + * API to get the current non-auto-compensated voltage for a voltage domain. + * Returns 0 in case of error else returns the current voltage. + */ +unsigned long voltdm_get_voltage(struct voltagedomain *voltdm) +{ + if (!voltdm || IS_ERR(voltdm)) { + pr_warn("%s: VDD specified does not exist!\n", __func__); + return 0; + } + + return voltdm->nominal_volt; +} + +/** + * voltdm_scale() - API to scale voltage of a particular voltage domain. + * @voltdm: pointer to the voltage domain which is to be scaled. + * @target_volt: The target voltage of the voltage domain + * + * This API should be called by the kernel to do the voltage scaling + * for a particular voltage domain during DVFS. + */ +static int voltdm_scale(struct voltagedomain *voltdm, + unsigned long target_volt) +{ + int ret, i; + unsigned long volt = 0; + + if (!voltdm || IS_ERR(voltdm)) { + pr_warn("%s: VDD specified does not exist!\n", __func__); + return -EINVAL; + } + + if (!voltdm->scale) { + pr_err("%s: No voltage scale API registered for vdd_%s\n", + __func__, voltdm->name); + return -ENODATA; + } + + if (!voltdm->volt_data) { + pr_err("%s: No voltage data defined for vdd_%s\n", + __func__, voltdm->name); + return -ENODATA; + } + + /* Adjust voltage to the exact voltage from the OPP table */ + for (i = 0; voltdm->volt_data[i].volt_nominal != 0; i++) { + if (voltdm->volt_data[i].volt_nominal >= target_volt) { + volt = voltdm->volt_data[i].volt_nominal; + break; + } + } + + if (!volt) { + pr_warn("%s: not scaling. OPP voltage for %lu, not found.\n", + __func__, target_volt); + return -EINVAL; + } + + ret = voltdm->scale(voltdm, volt); + if (!ret) + voltdm->nominal_volt = volt; + + return ret; +} + +/** + * voltdm_reset() - Resets the voltage of a particular voltage domain + * to that of the current OPP. + * @voltdm: pointer to the voltage domain whose voltage is to be reset. + * + * This API finds out the correct voltage the voltage domain is supposed + * to be at and resets the voltage to that level. Should be used especially + * while disabling any voltage compensation modules. + */ +void voltdm_reset(struct voltagedomain *voltdm) +{ + unsigned long target_volt; + + if (!voltdm || IS_ERR(voltdm)) { + pr_warn("%s: VDD specified does not exist!\n", __func__); + return; + } + + target_volt = voltdm_get_voltage(voltdm); + if (!target_volt) { + pr_err("%s: unable to find current voltage for vdd_%s\n", + __func__, voltdm->name); + return; + } + + voltdm_scale(voltdm, target_volt); +} + +/** + * omap_voltage_get_volttable() - API to get the voltage table associated with a + * particular voltage domain. + * @voltdm: pointer to the VDD for which the voltage table is required + * @volt_data: the voltage table for the particular vdd which is to be + * populated by this API + * + * This API populates the voltage table associated with a VDD into the + * passed parameter pointer. Returns the count of distinct voltages + * supported by this vdd. + * + */ +void omap_voltage_get_volttable(struct voltagedomain *voltdm, + struct omap_volt_data **volt_data) +{ + if (!voltdm || IS_ERR(voltdm)) { + pr_warn("%s: VDD specified does not exist!\n", __func__); + return; + } + + *volt_data = voltdm->volt_data; +} + +/** + * omap_voltage_get_voltdata() - API to get the voltage table entry for a + * particular voltage + * @voltdm: pointer to the VDD whose voltage table has to be searched + * @volt: the voltage to be searched in the voltage table + * + * This API searches through the voltage table for the required voltage + * domain and tries to find a matching entry for the passed voltage volt. + * If a matching entry is found volt_data is populated with that entry. + * This API searches only through the non-compensated voltages int the + * voltage table. + * Returns pointer to the voltage table entry corresponding to volt on + * success. Returns -ENODATA if no voltage table exisits for the passed voltage + * domain or if there is no matching entry. + */ +struct omap_volt_data *omap_voltage_get_voltdata(struct voltagedomain *voltdm, + unsigned long volt) +{ + int i; + + if (!voltdm || IS_ERR(voltdm)) { + pr_warn("%s: VDD specified does not exist!\n", __func__); + return ERR_PTR(-EINVAL); + } + + if (!voltdm->volt_data) { + pr_warn("%s: voltage table does not exist for vdd_%s\n", + __func__, voltdm->name); + return ERR_PTR(-ENODATA); + } + + for (i = 0; voltdm->volt_data[i].volt_nominal != 0; i++) { + if (voltdm->volt_data[i].volt_nominal == volt) + return &voltdm->volt_data[i]; + } + + pr_notice("%s: Unable to match the current voltage with the voltage table for vdd_%s\n", + __func__, voltdm->name); + + return ERR_PTR(-ENODATA); +} + +/** + * omap_voltage_register_pmic() - API to register PMIC specific data + * @voltdm: pointer to the VDD for which the PMIC specific data is + * to be registered + * @pmic: the structure containing pmic info + * + * This API is to be called by the SOC/PMIC file to specify the + * pmic specific info as present in omap_voltdm_pmic structure. + */ +int omap_voltage_register_pmic(struct voltagedomain *voltdm, + struct omap_voltdm_pmic *pmic) +{ + if (!voltdm || IS_ERR(voltdm)) { + pr_warn("%s: VDD specified does not exist!\n", __func__); + return -EINVAL; + } + + voltdm->pmic = pmic; + + return 0; +} + +/** + * omap_voltage_late_init() - Init the various voltage parameters + * + * This API is to be called in the later stages of the + * system boot to init the voltage controller and + * voltage processors. + */ +int __init omap_voltage_late_init(void) +{ + struct voltagedomain *voltdm; + + if (list_empty(&voltdm_list)) { + pr_err("%s: Voltage driver support not added\n", + __func__); + return -EINVAL; + } + + list_for_each_entry(voltdm, &voltdm_list, node) { + struct clk *sys_ck; + + if (!voltdm->scalable) + continue; + + sys_ck = clk_get(NULL, voltdm->sys_clk.name); + if (IS_ERR(sys_ck)) { + pr_warn("%s: Could not get sys clk.\n", __func__); + return -EINVAL; + } + voltdm->sys_clk.rate = clk_get_rate(sys_ck); + WARN_ON(!voltdm->sys_clk.rate); + clk_put(sys_ck); + + if (voltdm->vc) { + voltdm->scale = omap_vc_bypass_scale; + omap_vc_init_channel(voltdm); + } + + if (voltdm->vp) { + voltdm->scale = omap_vp_forceupdate_scale; + omap_vp_init(voltdm); + } + } + + return 0; +} + +static struct voltagedomain *_voltdm_lookup(const char *name) +{ + struct voltagedomain *voltdm, *temp_voltdm; + + voltdm = NULL; + + list_for_each_entry(temp_voltdm, &voltdm_list, node) { + if (!strcmp(name, temp_voltdm->name)) { + voltdm = temp_voltdm; + break; + } + } + + return voltdm; +} + +static int _voltdm_register(struct voltagedomain *voltdm) +{ + if (!voltdm || !voltdm->name) + return -EINVAL; + + list_add(&voltdm->node, &voltdm_list); + + pr_debug("voltagedomain: registered %s\n", voltdm->name); + + return 0; +} + +/** + * voltdm_lookup - look up a voltagedomain by name, return a pointer + * @name: name of voltagedomain + * + * Find a registered voltagedomain by its name @name. Returns a pointer + * to the struct voltagedomain if found, or NULL otherwise. + */ +struct voltagedomain *voltdm_lookup(const char *name) +{ + struct voltagedomain *voltdm ; + + if (!name) + return NULL; + + voltdm = _voltdm_lookup(name); + + return voltdm; +} + +/** + * voltdm_init - set up the voltagedomain layer + * @voltdm_list: array of struct voltagedomain pointers to register + * + * Loop through the array of voltagedomains @voltdm_list, registering all + * that are available on the current CPU. If voltdm_list is supplied + * and not null, all of the referenced voltagedomains will be + * registered. No return value. + */ +void voltdm_init(struct voltagedomain **voltdms) +{ + struct voltagedomain **v; + + if (voltdms) { + for (v = voltdms; *v; v++) + _voltdm_register(*v); + } +} |