diff options
Diffstat (limited to 'drivers/char/hw_random/rockchip-rng.c')
| -rw-r--r-- | drivers/char/hw_random/rockchip-rng.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/drivers/char/hw_random/rockchip-rng.c b/drivers/char/hw_random/rockchip-rng.c index 161050591663..fb4a30b95507 100644 --- a/drivers/char/hw_random/rockchip-rng.c +++ b/drivers/char/hw_random/rockchip-rng.c @@ -93,6 +93,30 @@ #define TRNG_v1_VERSION_CODE 0x46bc /* end of TRNG_V1 register definitions */ +/* + * RKRNG register definitions + * The RKRNG IP is a stand-alone TRNG implementation (not part of a crypto IP) + * and can be found in the Rockchip RK3576, Rockchip RK3562 and Rockchip RK3528 + * SoCs. It can either output true randomness (TRNG) or "deterministic" + * randomness derived from hashing the true entropy (DRNG). This driver + * implementation uses just the true entropy, and leaves stretching the entropy + * up to Linux. + */ +#define RKRNG_CFG 0x0000 +#define RKRNG_CTRL 0x0010 +#define RKRNG_CTRL_REQ_TRNG BIT(4) +#define RKRNG_STATE 0x0014 +#define RKRNG_STATE_TRNG_RDY BIT(4) +#define RKRNG_TRNG_DATA0 0x0050 +#define RKRNG_TRNG_DATA1 0x0054 +#define RKRNG_TRNG_DATA2 0x0058 +#define RKRNG_TRNG_DATA3 0x005C +#define RKRNG_TRNG_DATA4 0x0060 +#define RKRNG_TRNG_DATA5 0x0064 +#define RKRNG_TRNG_DATA6 0x0068 +#define RKRNG_TRNG_DATA7 0x006C +#define RKRNG_READ_LEN 32 + /* Before removing this assert, give rk3588_rng_read an upper bound of 32 */ static_assert(RK_RNG_MAX_BYTE <= (TRNG_V1_RAND7 + 4 - TRNG_V1_RAND0), "You raised RK_RNG_MAX_BYTE and broke rk3588-rng, congrats."); @@ -205,6 +229,46 @@ out: return (ret < 0) ? ret : to_read; } +static int rk3576_rng_init(struct hwrng *rng) +{ + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); + + return rk_rng_enable_clks(rk_rng); +} + +static int rk3576_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) +{ + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); + size_t to_read = min_t(size_t, max, RKRNG_READ_LEN); + int ret = 0; + u32 val; + + ret = pm_runtime_resume_and_get(rk_rng->dev); + if (ret < 0) + return ret; + + rk_rng_writel(rk_rng, RKRNG_CTRL_REQ_TRNG | (RKRNG_CTRL_REQ_TRNG << 16), + RKRNG_CTRL); + + if (readl_poll_timeout(rk_rng->base + RKRNG_STATE, val, + (val & RKRNG_STATE_TRNG_RDY), RK_RNG_POLL_PERIOD_US, + RK_RNG_POLL_TIMEOUT_US)) { + dev_err(rk_rng->dev, "timed out waiting for data\n"); + ret = -ETIMEDOUT; + goto out; + } + + rk_rng_writel(rk_rng, RKRNG_STATE_TRNG_RDY, RKRNG_STATE); + + memcpy_fromio(buf, rk_rng->base + RKRNG_TRNG_DATA0, to_read); + +out: + pm_runtime_mark_last_busy(rk_rng->dev); + pm_runtime_put_sync_autosuspend(rk_rng->dev); + + return (ret < 0) ? ret : to_read; +} + static int rk3588_rng_init(struct hwrng *rng) { struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); @@ -305,6 +369,14 @@ static const struct rk_rng_soc_data rk3568_soc_data = { .reset_optional = false, }; +static const struct rk_rng_soc_data rk3576_soc_data = { + .rk_rng_init = rk3576_rng_init, + .rk_rng_read = rk3576_rng_read, + .rk_rng_cleanup = rk3588_rng_cleanup, + .quality = 999, /* as determined by actual testing */ + .reset_optional = true, +}; + static const struct rk_rng_soc_data rk3588_soc_data = { .rk_rng_init = rk3588_rng_init, .rk_rng_read = rk3588_rng_read, @@ -397,6 +469,7 @@ static const struct dev_pm_ops rk_rng_pm_ops = { static const struct of_device_id rk_rng_dt_match[] = { { .compatible = "rockchip,rk3568-rng", .data = (void *)&rk3568_soc_data }, + { .compatible = "rockchip,rk3576-rng", .data = (void *)&rk3576_soc_data }, { .compatible = "rockchip,rk3588-rng", .data = (void *)&rk3588_soc_data }, { /* sentinel */ }, }; |