// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/init.h>

#include "common.h"

#include "voltage.h"
#include "vp.h"
#include "prm-regbits-34xx.h"
#include "prm-regbits-44xx.h"
#include "prm44xx.h"

static u32 _vp_set_init_voltage(struct voltagedomain *voltdm, u32 volt)
{
        struct omap_vp_instance *vp = voltdm->vp;
        u32 vpconfig;
        char vsel;

        vsel = voltdm->pmic->uv_to_vsel(volt);

        vpconfig = voltdm->read(vp->vpconfig);
        vpconfig &= ~(vp->common->vpconfig_initvoltage_mask |
                      vp->common->vpconfig_forceupdate |
                      vp->common->vpconfig_initvdd);
        vpconfig |= vsel << __ffs(vp->common->vpconfig_initvoltage_mask);
        voltdm->write(vpconfig, vp->vpconfig);

        /* Trigger initVDD value copy to voltage processor */
        voltdm->write((vpconfig | vp->common->vpconfig_initvdd),
                       vp->vpconfig);

        /* Clear initVDD copy trigger bit */
        voltdm->write(vpconfig, vp->vpconfig);

        return vpconfig;
}

/* Generic voltage init functions */
void __init omap_vp_init(struct voltagedomain *voltdm)
{
        struct omap_vp_instance *vp = voltdm->vp;
        u32 val, sys_clk_rate, timeout, waittime;
        u32 vddmin, vddmax, vstepmin, vstepmax;

        if (!voltdm->pmic || !voltdm->pmic->uv_to_vsel) {
                pr_err("%s: No PMIC info for vdd_%s\n", __func__, voltdm->name);
                return;
        }

        if (!voltdm->read || !voltdm->write) {
                pr_err("%s: No read/write API for accessing vdd_%s regs\n",
                        __func__, voltdm->name);
                return;
        }

        vp->enabled = false;

        /* Divide to avoid overflow */
        sys_clk_rate = voltdm->sys_clk.rate / 1000;

        timeout = (sys_clk_rate * voltdm->pmic->vp_timeout_us) / 1000;
        vddmin = max(voltdm->vp_param->vddmin, voltdm->pmic->vddmin);
        vddmax = min(voltdm->vp_param->vddmax, voltdm->pmic->vddmax);
        vddmin = voltdm->pmic->uv_to_vsel(vddmin);
        vddmax = voltdm->pmic->uv_to_vsel(vddmax);

        waittime = DIV_ROUND_UP(voltdm->pmic->step_size * sys_clk_rate,
                                1000 * voltdm->pmic->slew_rate);
        vstepmin = voltdm->pmic->vp_vstepmin;
        vstepmax = voltdm->pmic->vp_vstepmax;

        /*
         * VP_CONFIG: error gain is not set here, it will be updated
         * on each scale, based on OPP.
         */
        val = (voltdm->pmic->vp_erroroffset <<
               __ffs(voltdm->vp->common->vpconfig_erroroffset_mask)) |
                vp->common->vpconfig_timeouten;
        voltdm->write(val, vp->vpconfig);

        /* VSTEPMIN */
        val = (waittime << vp->common->vstepmin_smpswaittimemin_shift) |
                (vstepmin <<  vp->common->vstepmin_stepmin_shift);
        voltdm->write(val, vp->vstepmin);

        /* VSTEPMAX */
        val = (vstepmax << vp->common->vstepmax_stepmax_shift) |
                (waittime << vp->common->vstepmax_smpswaittimemax_shift);
        voltdm->write(val, vp->vstepmax);

        /* VLIMITTO */
        val = (vddmax << vp->common->vlimitto_vddmax_shift) |
                (vddmin << vp->common->vlimitto_vddmin_shift) |
                (timeout <<  vp->common->vlimitto_timeout_shift);
        voltdm->write(val, vp->vlimitto);
}

int omap_vp_update_errorgain(struct voltagedomain *voltdm,
                             unsigned long target_volt)
{
        struct omap_volt_data *volt_data;

        if (!voltdm->vp)
                return -EINVAL;

        /* Get volt_data corresponding to target_volt */
        volt_data = omap_voltage_get_voltdata(voltdm, target_volt);
        if (IS_ERR(volt_data))
                return -EINVAL;

        /* Setting vp errorgain based on the voltage */
        voltdm->rmw(voltdm->vp->common->vpconfig_errorgain_mask,
                    volt_data->vp_errgain <<
                    __ffs(voltdm->vp->common->vpconfig_errorgain_mask),
                    voltdm->vp->vpconfig);

        return 0;
}

/* VP force update method of voltage scaling */
int omap_vp_forceupdate_scale(struct voltagedomain *voltdm,
                              unsigned long target_volt)
{
        struct omap_vp_instance *vp = voltdm->vp;
        u32 vpconfig;
        u8 target_vsel, current_vsel;
        int ret, timeout = 0;

        ret = omap_vc_pre_scale(voltdm, target_volt, &target_vsel, &current_vsel);
        if (ret)
                return ret;

        /*
         * Clear all pending TransactionDone interrupt/status. Typical latency
         * is <3us
         */
        while (timeout++ < VP_TRANXDONE_TIMEOUT) {
                vp->common->ops->clear_txdone(vp->id);
                if (!vp->common->ops->check_txdone(vp->id))
                        break;
                udelay(1);
        }
        if (timeout >= VP_TRANXDONE_TIMEOUT) {
                pr_warn("%s: vdd_%s TRANXDONE timeout exceeded. Voltage change aborted\n",
                        __func__, voltdm->name);
                return -ETIMEDOUT;
        }

        vpconfig = _vp_set_init_voltage(voltdm, target_volt);

        /* Force update of voltage */
        voltdm->write(vpconfig | vp->common->vpconfig_forceupdate,
                      voltdm->vp->vpconfig);

        /*
         * Wait for TransactionDone. Typical latency is <200us.
         * Depends on SMPSWAITTIMEMIN/MAX and voltage change
         */
        timeout = 0;
        omap_test_timeout(vp->common->ops->check_txdone(vp->id),
                          VP_TRANXDONE_TIMEOUT, timeout);
        if (timeout >= VP_TRANXDONE_TIMEOUT)
                pr_err("%s: vdd_%s TRANXDONE timeout exceeded. TRANXDONE never got set after the voltage update\n",
                       __func__, voltdm->name);

        omap_vc_post_scale(voltdm, target_volt, target_vsel, current_vsel);

        /*
         * Disable TransactionDone interrupt , clear all status, clear
         * control registers
         */
        timeout = 0;
        while (timeout++ < VP_TRANXDONE_TIMEOUT) {
                vp->common->ops->clear_txdone(vp->id);
                if (!vp->common->ops->check_txdone(vp->id))
                        break;
                udelay(1);
        }

        if (timeout >= VP_TRANXDONE_TIMEOUT)
                pr_warn("%s: vdd_%s TRANXDONE timeout exceeded while trying to clear the TRANXDONE status\n",
                        __func__, voltdm->name);

        /* Clear force bit */
        voltdm->write(vpconfig, vp->vpconfig);

        return 0;
}

/**
 * omap_vp_enable() - API to enable a particular VP
 * @voltdm:     pointer to the VDD whose VP is to be enabled.
 *
 * This API enables a particular voltage processor. Needed by the smartreflex
 * class drivers.
 */
void omap_vp_enable(struct voltagedomain *voltdm)
{
        struct omap_vp_instance *vp;
        u32 vpconfig, volt;

        if (IS_ERR_OR_NULL(voltdm)) {
                pr_warn("%s: VDD specified does not exist!\n", __func__);
                return;
        }

        vp = voltdm->vp;
        if (!voltdm->read || !voltdm->write) {
                pr_err("%s: No read/write API for accessing vdd_%s regs\n",
                        __func__, voltdm->name);
                return;
        }

        /* If VP is already enabled, do nothing. Return */
        if (vp->enabled)
                return;

        volt = voltdm_get_voltage(voltdm);
        if (!volt) {
                pr_warn("%s: unable to find current voltage for %s\n",
                        __func__, voltdm->name);
                return;
        }

        vpconfig = _vp_set_init_voltage(voltdm, volt);

        /* Enable VP */
        vpconfig |= vp->common->vpconfig_vpenable;
        voltdm->write(vpconfig, vp->vpconfig);

        vp->enabled = true;
}

/**
 * omap_vp_disable() - API to disable a particular VP
 * @voltdm:     pointer to the VDD whose VP is to be disabled.
 *
 * This API disables a particular voltage processor. Needed by the smartreflex
 * class drivers.
 */
void omap_vp_disable(struct voltagedomain *voltdm)
{
        struct omap_vp_instance *vp;
        u32 vpconfig;
        int timeout;

        if (IS_ERR_OR_NULL(voltdm)) {
                pr_warn("%s: VDD specified does not exist!\n", __func__);
                return;
        }

        vp = voltdm->vp;
        if (!voltdm->read || !voltdm->write) {
                pr_err("%s: No read/write API for accessing vdd_%s regs\n",
                        __func__, voltdm->name);
                return;
        }

        /* If VP is already disabled, do nothing. Return */
        if (!vp->enabled) {
                pr_warn("%s: Trying to disable VP for vdd_%s when it is already disabled\n",
                        __func__, voltdm->name);
                return;
        }

        /* Disable VP */
        vpconfig = voltdm->read(vp->vpconfig);
        vpconfig &= ~vp->common->vpconfig_vpenable;
        voltdm->write(vpconfig, vp->vpconfig);

        /*
         * Wait for VP idle Typical latency is <2us. Maximum latency is ~100us
         */
        omap_test_timeout((voltdm->read(vp->vstatus)),
                          VP_IDLE_TIMEOUT, timeout);

        if (timeout >= VP_IDLE_TIMEOUT)
                pr_warn("%s: vdd_%s idle timedout\n", __func__, voltdm->name);

        vp->enabled = false;

        return;
}