On 24/10/2019 20:04:52+0300, Codrin Ciubotariu wrote:
> Add platform support for the new IP found on sam9x60 SoC. For this
> version, if the peripheral clk is above 100MHz, the HALFR bit must be
> set. This bit is available only if the IP can generate a random number
> every 168 cycles (instead of 84).
>
> Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>
> ---
> drivers/char/hw_random/atmel-rng.c | 39 ++++++++++++++++++++++++++++--
> 1 file changed, 37 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c
> index e55705745d5e..0aa9425e6c3e 100644
> --- a/drivers/char/hw_random/atmel-rng.c
> +++ b/drivers/char/hw_random/atmel-rng.c
> @@ -14,14 +14,22 @@
> #include <linux/clk.h>
> #include <linux/io.h>
> #include <linux/hw_random.h>
> +#include <linux/of_device.h>
> #include <linux/platform_device.h>
>
> #define TRNG_CR 0x00
> +#define TRNG_MR 0x04
> #define TRNG_ISR 0x1c
> #define TRNG_ODATA 0x50
>
> #define TRNG_KEY 0x524e4700 /* RNG */
>
> +#define TRNG_HALFR BIT(0) /* generate RN every 168 cycles */
> +
> +struct atmel_trng_pdata {
Could that be just atmel_trng_data?
There is no platform data in this driver and it is DT only.
> + bool has_half_rate;
> +};
> +
> struct atmel_trng {
> struct clk *clk;
> void __iomem *base;
> @@ -63,6 +71,7 @@ static int atmel_trng_probe(struct platform_device *pdev)
> {
> struct atmel_trng *trng;
> struct resource *res;
> + const struct atmel_trng_pdata *pdata;
> int ret;
>
> trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
> @@ -77,6 +86,17 @@ static int atmel_trng_probe(struct platform_device *pdev)
> trng->clk = devm_clk_get(&pdev->dev, NULL);
> if (IS_ERR(trng->clk))
> return PTR_ERR(trng->clk);
> + pdata = of_device_get_match_data(&pdev->dev);
> + if (!pdata)
> + return -ENODEV;
> +
> + if (pdata->has_half_rate) {
> + unsigned long rate = clk_get_rate(trng->clk);
> +
> + /* if peripheral clk is above 100MHz, set HALFR */
> + if (rate > 100000000)
> + writel(TRNG_HALFR, trng->base + TRNG_MR);
> + }
>
> ret = clk_prepare_enable(trng->clk);
> if (ret)
> @@ -141,9 +161,24 @@ static const struct dev_pm_ops atmel_trng_pm_ops = {
> };
> #endif /* CONFIG_PM */
>
> +static struct atmel_trng_pdata at91sam9g45_config = {
> + .has_half_rate = false,
> +};
> +
> +static struct atmel_trng_pdata sam9x60_config = {
> + .has_half_rate = true,
> +};
> +
> static const struct of_device_id atmel_trng_dt_ids[] = {
> - { .compatible = "atmel,at91sam9g45-trng" },
> - { /* sentinel */ }
> + {
> + .compatible = "atmel,at91sam9g45-trng",
> + .data = &at91sam9g45_config,
> + }, {
> + .compatible = "microchip,sam9x60-trng",
> + .data = &sam9x60_config,
> + }, {
> + /* sentinel */
> + }
> };
> MODULE_DEVICE_TABLE(of, atmel_trng_dt_ids);
>
> --
> 2.20.1
>
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
