// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright(C) 2020 Linaro Limited. All rights reserved.
 * Author: Mike Leach <mike.leach@linaro.org>
 */

#include <linux/sysfs.h>
#include "coresight-config.h"
#include "coresight-priv.h"

/*
 * This provides a set of generic functions that operate on configurations
 * and features to manage the handling of parameters, the programming and
 * saving of registers used by features on devices.
 */

/*
 * Write the value held in the register structure into the driver internal memory
 * location.
 */
static void cscfg_set_reg(struct cscfg_regval_csdev *reg_csdev)
{
        u32 *p_val32 = (u32 *)reg_csdev->driver_regval;
        u32 tmp32 = reg_csdev->reg_desc.val32;

        if (reg_csdev->reg_desc.type & CS_CFG_REG_TYPE_VAL_64BIT) {
                *((u64 *)reg_csdev->driver_regval) = reg_csdev->reg_desc.val64;
                return;
        }

        if (reg_csdev->reg_desc.type & CS_CFG_REG_TYPE_VAL_MASK) {
                tmp32 = *p_val32;
                tmp32 &= ~reg_csdev->reg_desc.mask32;
                tmp32 |= reg_csdev->reg_desc.val32 & reg_csdev->reg_desc.mask32;
        }
        *p_val32 = tmp32;
}

/*
 * Read the driver value into the reg if this is marked as one we want to save.
 */
static void cscfg_save_reg(struct cscfg_regval_csdev *reg_csdev)
{
        if (!(reg_csdev->reg_desc.type & CS_CFG_REG_TYPE_VAL_SAVE))
                return;
        if (reg_csdev->reg_desc.type & CS_CFG_REG_TYPE_VAL_64BIT)
                reg_csdev->reg_desc.val64 = *(u64 *)(reg_csdev->driver_regval);
        else
                reg_csdev->reg_desc.val32 = *(u32 *)(reg_csdev->driver_regval);
}

/*
 * Some register values are set from parameters. Initialise these registers
 * from the current parameter values.
 */
static void cscfg_init_reg_param(struct cscfg_feature_csdev *feat_csdev,
                                 struct cscfg_regval_desc *reg_desc,
                                 struct cscfg_regval_csdev *reg_csdev)
{
        struct cscfg_parameter_csdev *param_csdev;

        /* for param, load routines have validated the index */
        param_csdev = &feat_csdev->params_csdev[reg_desc->param_idx];
        param_csdev->reg_csdev = reg_csdev;
        param_csdev->val64 = reg_csdev->reg_desc.type & CS_CFG_REG_TYPE_VAL_64BIT;

        if (param_csdev->val64)
                reg_csdev->reg_desc.val64 = param_csdev->current_value;
        else
                reg_csdev->reg_desc.val32 = (u32)param_csdev->current_value;
}

/* set values into the driver locations referenced in cscfg_reg_csdev */
static int cscfg_set_on_enable(struct cscfg_feature_csdev *feat_csdev)
{
        unsigned long flags;
        int i;

        spin_lock_irqsave(feat_csdev->drv_spinlock, flags);
        for (i = 0; i < feat_csdev->nr_regs; i++)
                cscfg_set_reg(&feat_csdev->regs_csdev[i]);
        spin_unlock_irqrestore(feat_csdev->drv_spinlock, flags);
        dev_dbg(&feat_csdev->csdev->dev, "Feature %s: %s",
                feat_csdev->feat_desc->name, "set on enable");
        return 0;
}

/* copy back values from the driver locations referenced in cscfg_reg_csdev */
static void cscfg_save_on_disable(struct cscfg_feature_csdev *feat_csdev)
{
        unsigned long flags;
        int i;

        spin_lock_irqsave(feat_csdev->drv_spinlock, flags);
        for (i = 0; i < feat_csdev->nr_regs; i++)
                cscfg_save_reg(&feat_csdev->regs_csdev[i]);
        spin_unlock_irqrestore(feat_csdev->drv_spinlock, flags);
        dev_dbg(&feat_csdev->csdev->dev, "Feature %s: %s",
                feat_csdev->feat_desc->name, "save on disable");
}

/* default reset - restore default values */
void cscfg_reset_feat(struct cscfg_feature_csdev *feat_csdev)
{
        struct cscfg_regval_desc *reg_desc;
        struct cscfg_regval_csdev *reg_csdev;
        int i;

        /*
         * set the default values for all parameters and regs from the
         * relevant static descriptors.
         */
        for (i = 0; i < feat_csdev->nr_params; i++)
                feat_csdev->params_csdev[i].current_value =
                        feat_csdev->feat_desc->params_desc[i].value;

        for (i = 0; i < feat_csdev->nr_regs; i++) {
                reg_desc = &feat_csdev->feat_desc->regs_desc[i];
                reg_csdev = &feat_csdev->regs_csdev[i];
                reg_csdev->reg_desc.type = reg_desc->type;

                /* check if reg set from a parameter otherwise desc default */
                if (reg_desc->type & CS_CFG_REG_TYPE_VAL_PARAM)
                        cscfg_init_reg_param(feat_csdev, reg_desc, reg_csdev);
                else
                        /*
                         * for normal values the union between val64 & val32 + mask32
                         * allows us to init using the 64 bit value
                         */
                        reg_csdev->reg_desc.val64 = reg_desc->val64;
        }
}

/*
 * For the selected presets, we set the register associated with the parameter, to
 * the value of the preset index associated with the parameter.
 */
static int cscfg_update_presets(struct cscfg_config_csdev *config_csdev, int preset)
{
        int i, j, val_idx = 0, nr_cfg_params;
        struct cscfg_parameter_csdev *param_csdev;
        struct cscfg_feature_csdev *feat_csdev;
        const struct cscfg_config_desc *config_desc = config_csdev->config_desc;
        const char *name;
        const u64 *preset_base;
        u64 val;

        /* preset in range 1 to nr_presets */
        if (preset < 1 || preset > config_desc->nr_presets)
                return -EINVAL;
        /*
         * Go through the array of features, assigning preset values to
         * feature parameters in the order they appear.
         * There should be precisely the same number of preset values as the
         * sum of number of parameters over all the features - but we will
         * ensure there is no overrun.
         */
        nr_cfg_params = config_desc->nr_total_params;
        preset_base = &config_desc->presets[(preset - 1) * nr_cfg_params];
        for (i = 0; i < config_csdev->nr_feat; i++) {
                feat_csdev = config_csdev->feats_csdev[i];
                if (!feat_csdev->nr_params)
                        continue;

                for (j = 0; j < feat_csdev->nr_params; j++) {
                        param_csdev = &feat_csdev->params_csdev[j];
                        name = feat_csdev->feat_desc->params_desc[j].name;
                        val = preset_base[val_idx++];
                        if (param_csdev->val64) {
                                dev_dbg(&config_csdev->csdev->dev,
                                        "set param %s (%lld)", name, val);
                                param_csdev->reg_csdev->reg_desc.val64 = val;
                        } else {
                                param_csdev->reg_csdev->reg_desc.val32 = (u32)val;
                                dev_dbg(&config_csdev->csdev->dev,
                                        "set param %s (%d)", name, (u32)val);
                        }
                }

                /* exit early if all params filled */
                if (val_idx >= nr_cfg_params)
                        break;
        }
        return 0;
}

/*
 * if we are not using a preset, then need to update the feature params
 * with current values. This sets the register associated with the parameter
 * with the current value of that parameter.
 */
static int cscfg_update_curr_params(struct cscfg_config_csdev *config_csdev)
{
        int i, j;
        struct cscfg_feature_csdev *feat_csdev;
        struct cscfg_parameter_csdev *param_csdev;
        const char *name;
        u64 val;

        for (i = 0; i < config_csdev->nr_feat; i++) {
                feat_csdev = config_csdev->feats_csdev[i];
                if (!feat_csdev->nr_params)
                        continue;
                for (j = 0; j < feat_csdev->nr_params; j++) {
                        param_csdev = &feat_csdev->params_csdev[j];
                        name = feat_csdev->feat_desc->params_desc[j].name;
                        val = param_csdev->current_value;
                        if (param_csdev->val64) {
                                dev_dbg(&config_csdev->csdev->dev,
                                        "set param %s (%lld)", name, val);
                                param_csdev->reg_csdev->reg_desc.val64 = val;
                        } else {
                                param_csdev->reg_csdev->reg_desc.val32 = (u32)val;
                                dev_dbg(&config_csdev->csdev->dev,
                                        "set param %s (%d)", name, (u32)val);
                        }
                }
        }
        return 0;
}

/*
 * Configuration values will be programmed into the driver locations if enabling, or read
 * from relevant locations on disable.
 */
static int cscfg_prog_config(struct cscfg_config_csdev *config_csdev, bool enable)
{
        int i, err = 0;
        struct cscfg_feature_csdev *feat_csdev;
        struct coresight_device *csdev;

        for (i = 0; i < config_csdev->nr_feat; i++) {
                feat_csdev = config_csdev->feats_csdev[i];
                csdev = feat_csdev->csdev;
                dev_dbg(&csdev->dev, "cfg %s;  %s feature:%s", config_csdev->config_desc->name,
                        enable ? "enable" : "disable", feat_csdev->feat_desc->name);

                if (enable)
                        err = cscfg_set_on_enable(feat_csdev);
                else
                        cscfg_save_on_disable(feat_csdev);

                if (err)
                        break;
        }
        return err;
}

/*
 * Enable configuration for the device. Will result in the internal driver data
 * being updated ready for programming into the device.
 *
 * @config_csdev:       config_csdev to set.
 * @preset:             preset values to use - 0 for default.
 */
int cscfg_csdev_enable_config(struct cscfg_config_csdev *config_csdev, int preset)
{
        int err = 0;

        if (preset)
                err = cscfg_update_presets(config_csdev, preset);
        else
                err = cscfg_update_curr_params(config_csdev);
        if (!err)
                err = cscfg_prog_config(config_csdev, true);
        return err;
}

void cscfg_csdev_disable_config(struct cscfg_config_csdev *config_csdev)
{
        cscfg_prog_config(config_csdev, false);
}