// SPDX-License-Identifier: GPL-2.0-or-later
#include "sun4i-ss.h"

int sun4i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed,
                       unsigned int slen)
{
        struct sun4i_ss_alg_template *algt;
        struct rng_alg *alg = crypto_rng_alg(tfm);

        algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
        memcpy(algt->ss->seed, seed, slen);

        return 0;
}

int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
                           unsigned int slen, u8 *dst, unsigned int dlen)
{
        struct sun4i_ss_alg_template *algt;
        struct rng_alg *alg = crypto_rng_alg(tfm);
        int i, err;
        u32 v;
        u32 *data = (u32 *)dst;
        const u32 mode = SS_OP_PRNG | SS_PRNG_CONTINUE | SS_ENABLED;
        size_t len;
        struct sun4i_ss_ctx *ss;
        unsigned int todo = (dlen / 4) * 4;

        algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
        ss = algt->ss;

        err = pm_runtime_resume_and_get(ss->dev);
        if (err < 0)
                return err;

        if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN4I_SS_DEBUG)) {
                algt->stat_req++;
                algt->stat_bytes += todo;
        }

        spin_lock_bh(&ss->slock);

        writel(mode, ss->base + SS_CTL);

        while (todo > 0) {
                /* write the seed */
                for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++)
                        writel(ss->seed[i], ss->base + SS_KEY0 + i * 4);

                /* Read the random data */
                len = min_t(size_t, SS_DATA_LEN / BITS_PER_BYTE, todo);
                readsl(ss->base + SS_TXFIFO, data, len / 4);
                data += len / 4;
                todo -= len;

                /* Update the seed */
                for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++) {
                        v = readl(ss->base + SS_KEY0 + i * 4);
                        ss->seed[i] = v;
                }
        }

        writel(0, ss->base + SS_CTL);
        spin_unlock_bh(&ss->slock);

        pm_runtime_put(ss->dev);

        return 0;
}