On Mon, Dec 11, 2017 at 3:06 PM, Łukasz Stelmach <l.stelmach@xxxxxxxxxxx> wrote:
> Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>, Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
>
> Add support for PRNG in Exynos5250+ SoCs.
>
> Signed-off-by: Łukasz Stelmach <l.stelmach@xxxxxxxxxxx>
> ---
> .../bindings/crypto/samsung,exynos-rng4.txt | 4 ++-
> drivers/crypto/exynos-rng.c | 32 ++++++++++++++++++++--
> 2 files changed, 33 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/crypto/samsung,exynos-rng4.txt b/Documentation/devicetree/bindings/crypto/samsung,exynos-rng4.txt
> index 4ca8dd4d7e66..a13fbdb4bd88 100644
> --- a/Documentation/devicetree/bindings/crypto/samsung,exynos-rng4.txt
> +++ b/Documentation/devicetree/bindings/crypto/samsung,exynos-rng4.txt
> @@ -2,7 +2,9 @@ Exynos Pseudo Random Number Generator
>
> Required properties:
>
> -- compatible : Should be "samsung,exynos4-rng".
> +- compatible : One of:
> + - "samsung,exynos4-rng" for Exynos4210 and Exynos4412
> + - "samsung,exynos5250-prng" for Exynos5250+
> - reg : Specifies base physical address and size of the registers map.
> - clocks : Phandle to clock-controller plus clock-specifier pair.
> - clock-names : "secss" as a clock name.
> diff --git a/drivers/crypto/exynos-rng.c b/drivers/crypto/exynos-rng.c
> index ed6ba796ad71..2f554b82f49f 100644
> --- a/drivers/crypto/exynos-rng.c
> +++ b/drivers/crypto/exynos-rng.c
> @@ -22,12 +22,17 @@
> #include <linux/err.h>
> #include <linux/io.h>
> #include <linux/module.h>
> +#include <linux/of_device.h>
> #include <linux/platform_device.h>
>
> #include <crypto/internal/rng.h>
>
> #define EXYNOS_RNG_CONTROL 0x0
> #define EXYNOS_RNG_STATUS 0x10
> +
> +#define EXYNOS_RNG_SEED_CONF 0x14
> +#define EXYNOS_RNG_GEN_PRNG BIT(1)
> +
> #define EXYNOS_RNG_SEED_BASE 0x140
> #define EXYNOS_RNG_SEED(n) (EXYNOS_RNG_SEED_BASE + (n * 0x4))
> #define EXYNOS_RNG_OUT_BASE 0x160
> @@ -43,6 +48,12 @@
> #define EXYNOS_RNG_SEED_REGS 5
> #define EXYNOS_RNG_SEED_SIZE (EXYNOS_RNG_SEED_REGS * 4)
>
> +enum exynos_prng_type {
> + EXYNOS_PRNG_UNKNOWN = 0,
> + EXYNOS_PRNG_EXYNOS4,
> + EXYNOS_PRNG_EXYNOS5,
> +};
> +
> /*
> * Driver re-seeds itself with generated random numbers to increase
> * the randomness.
> @@ -63,6 +74,7 @@ struct exynos_rng_ctx {
> /* Device associated memory */
> struct exynos_rng_dev {
> struct device *dev;
> + enum exynos_prng_type type;
> void __iomem *mem;
> struct clk *clk;
> /* Generated numbers stored for seeding during resume */
> @@ -160,8 +172,13 @@ static int exynos_rng_get_random(struct exynos_rng_dev *rng,
> {
> int retry = EXYNOS_RNG_WAIT_RETRIES;
>
> - exynos_rng_writel(rng, EXYNOS_RNG_CONTROL_START,
> - EXYNOS_RNG_CONTROL);
> + if (rng->type == EXYNOS_PRNG_EXYNOS4) {
> + exynos_rng_writel(rng, EXYNOS_RNG_CONTROL_START,
> + EXYNOS_RNG_CONTROL);
> + } else if (rng->type == EXYNOS_PRNG_EXYNOS5) {
> + exynos_rng_writel(rng, EXYNOS_RNG_GEN_PRNG,
> + EXYNOS_RNG_SEED_CONF);
> + }
>
> while (!(exynos_rng_readl(rng,
> EXYNOS_RNG_STATUS) & EXYNOS_RNG_STATUS_RNG_DONE) && --retry)
> @@ -279,6 +296,13 @@ static int exynos_rng_probe(struct platform_device *pdev)
> if (!rng)
> return -ENOMEM;
>
> + rng->type = (enum exynos_prng_type)of_device_get_match_data(&pdev->dev);
> + if (rng->type != EXYNOS_PRNG_EXYNOS4 &&
> + rng->type != EXYNOS_PRNG_EXYNOS5) {
> + dev_err(&pdev->dev, "Unsupported PRNG type: %d", rng->type);
> + return -ENOTSUPP;
> + }
> +
This cannot happen. Device will be matched only on matching compatible
thus rng->type will be always correct.
Best regards,
Krzysztof
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