mirror of
https://github.com/AsahiLinux/u-boot
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156 lines
3.2 KiB
C
156 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (c) 2022 Nuvoton Technology Corp.
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*/
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#include <common.h>
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#include <dm.h>
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#include <malloc.h>
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#include <rng.h>
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#include <uboot_aes.h>
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#include <asm/io.h>
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#define RNGCS_RNGE BIT(0)
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#define RNGCS_DVALID BIT(1)
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#define RNGCS_CLKP(range) ((0x0f & (range)) << 2)
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#define RNGMODE_M1ROSEL_VAL (0x02) /* Ring Oscillator Select for Method I */
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enum {
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RNG_CLKP_80_100_MHZ = 0x00, /*default */
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RNG_CLKP_60_80_MHZ = 0x01,
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RNG_CLKP_50_60_MHZ = 0x02,
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RNG_CLKP_40_50_MHZ = 0x03,
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RNG_CLKP_30_40_MHZ = 0x04,
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RNG_CLKP_25_30_MHZ = 0x05,
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RNG_CLKP_20_25_MHZ = 0x06,
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RNG_CLKP_5_20_MHZ = 0x07,
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RNG_CLKP_2_15_MHZ = 0x08,
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RNG_CLKP_9_12_MHZ = 0x09,
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RNG_CLKP_7_9_MHZ = 0x0A,
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RNG_CLKP_6_7_MHZ = 0x0B,
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RNG_CLKP_5_6_MHZ = 0x0C,
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RNG_CLKP_4_5_MHZ = 0x0D,
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RNG_CLKP_3_4_MHZ = 0x0E,
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RNG_NUM_OF_CLKP
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};
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struct npcm_rng_regs {
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unsigned int rngcs;
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unsigned int rngd;
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unsigned int rngmode;
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};
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struct npcm_rng_priv {
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struct npcm_rng_regs *regs;
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};
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static struct npcm_rng_priv *rng_priv;
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void npcm_rng_init(void)
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{
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struct npcm_rng_regs *regs = rng_priv->regs;
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int init;
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/* check if rng enabled */
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init = readb(®s->rngcs);
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if ((init & RNGCS_RNGE) == 0) {
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/* init rng */
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writeb(RNGCS_CLKP(RNG_CLKP_20_25_MHZ) | RNGCS_RNGE, ®s->rngcs);
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writeb(RNGMODE_M1ROSEL_VAL, ®s->rngmode);
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}
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}
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void npcm_rng_disable(void)
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{
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struct npcm_rng_regs *regs = rng_priv->regs;
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/* disable rng */
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writeb(0, ®s->rngcs);
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writeb(0, ®s->rngmode);
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}
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void srand(unsigned int seed)
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{
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/* no need to seed for now */
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}
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int npcm_rng_read(struct udevice *dev, void *data, size_t max)
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{
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struct npcm_rng_regs *regs = rng_priv->regs;
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int i;
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int ret_val = 0;
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char *buf = data;
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npcm_rng_init();
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printf("NPCM HW RNG\n");
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/* Wait for RNG done (max bytes) */
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for (i = 0; i < max; i++) {
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/* wait until DVALID is set */
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while ((readb(®s->rngcs) & RNGCS_DVALID) == 0)
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;
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buf[i] = ((unsigned int)readb(®s->rngd) & 0x000000FF);
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}
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return ret_val;
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}
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unsigned int rand_r(unsigned int *seedp)
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{
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struct npcm_rng_regs *regs = rng_priv->regs;
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int i;
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unsigned int ret_val = 0;
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npcm_rng_init();
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/* Wait for RNG done (4 bytes) */
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for (i = 0; i < 4 ; i++) {
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/* wait until DVALID is set */
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while ((readb(®s->rngcs) & RNGCS_DVALID) == 0)
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;
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ret_val |= (((unsigned int)readb(®s->rngd) & 0x000000FF) << (i * 8));
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}
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return ret_val;
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}
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unsigned int rand(void)
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{
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return rand_r(NULL);
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}
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static int npcm_rng_bind(struct udevice *dev)
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{
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rng_priv = calloc(1, sizeof(struct npcm_rng_priv));
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if (!rng_priv)
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return -ENOMEM;
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rng_priv->regs = dev_remap_addr_index(dev, 0);
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if (!rng_priv->regs) {
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printf("Cannot find rng reg address, binding failed\n");
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return -EINVAL;
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}
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printf("RNG: NPCM RNG module bind OK\n");
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return 0;
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}
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static const struct udevice_id npcm_rng_ids[] = {
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{ .compatible = "nuvoton,npcm845-rng" },
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{ .compatible = "nuvoton,npcm750-rng" },
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{ }
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};
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static const struct dm_rng_ops npcm_rng_ops = {
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.read = npcm_rng_read,
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};
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U_BOOT_DRIVER(npcm_rng) = {
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.name = "npcm_rng",
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.id = UCLASS_RNG,
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.ops = &npcm_rng_ops,
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.of_match = npcm_rng_ids,
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.priv_auto = sizeof(struct npcm_rng_priv),
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.bind = npcm_rng_bind,
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};
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