Re: [PATCH v2 1/1] drivers: rng: add support for Meson S4

Hi,

On 10/10/2023 13:13, Alexey Romanov wrote:

For some Amlogic SOC's, mechanism to obtain random number has been changed. For example, S4 now uses status bit waiting algo.

Signed-off-by: Alexey Romanov avromanov@salutedevices.com

drivers/rng/meson-rng.c | 72 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 71 insertions(+), 1 deletion(-)

diff --git a/drivers/rng/meson-rng.c b/drivers/rng/meson-rng.c index e0a1e8c7e0..ba60325b94 100644 --- a/drivers/rng/meson-rng.c +++ b/drivers/rng/meson-rng.c @@ -10,10 +10,23 @@ #include <dm.h> #include <rng.h> #include <asm/io.h> +#include <linux/iopoll.h>

+#define RNG_DATA 0x00 +#define RNG_S4_DATA 0x08 +#define RNG_S4_CFG 0x00

+#define RUN_BIT BIT(0) +#define SEED_READY_STS_BIT BIT(31)

+struct meson_rng_priv {

• u32 (*read)(fdt_addr_t base);

+};

struct meson_rng_plat { fdt_addr_t base; struct clk clk;

• struct meson_rng_priv *priv; };

  /**

@@ -27,10 +40,11 @@ struct meson_rng_plat { static int meson_rng_read(struct udevice *dev, void *data, size_t len) { struct meson_rng_plat *pdata = dev_get_plat(dev);

• struct meson_rng_priv *priv = pdata->priv; char *buffer = (char *)data;

  while (len) {

• u32 rand = readl(pdata->base);
  

• u32 rand = priv->read(pdata->base);
  

  size_t step;

  if (len >= 4)

@@ -44,6 +58,47 @@ static int meson_rng_read(struct udevice *dev, void *data, size_t len) return 0; }

+static int meson_rng_wait_status(void __iomem *cfg_addr, int bit) +{

• u32 status = 0;
• int ret;
• ret = readl_relaxed_poll_timeout(cfg_addr,

• 			 status, !(status & bit),
  

• 			 10000);
  

• if (ret)

• return -EBUSY;
  

• return 0;

+}

+static u32 meson_common_rng_read(fdt_addr_t base) +{

• return readl(base);

+}

+static u32 meson_s4_rng_read(fdt_addr_t base) +{

• void __iomem *cfg_addr = (void *)base + RNG_S4_CFG;
• int err;
• writel_relaxed(readl_relaxed(cfg_addr) | SEED_READY_STS_BIT, cfg_addr);
• err = meson_rng_wait_status(cfg_addr, SEED_READY_STS_BIT);
• if (err) {

• pr_err("Seed isn't ready, try again\n");
  

• return err;
  

• }
• err = meson_rng_wait_status(cfg_addr, RUN_BIT);
• if (err) {

• pr_err("Can't get random number, try again\n");
  

• return err;
  

• }
• return readl_relaxed(base + RNG_S4_DATA);

+}

• /**
  • meson_rng_probe() - probe rng device

@@ -59,6 +114,8 @@ static int meson_rng_probe(struct udevice *dev) if (err) return err;

• pdata->priv = dev_get_driver_data(dev);
• return 0; }

@@ -102,9 +159,22 @@ static const struct dm_rng_ops meson_rng_ops = { .read = meson_rng_read, };

+static const struct meson_rng_priv meson_rng_priv = {

• .read = meson_common_rng_read,

+};

+static const struct meson_rng_priv meson_rng_priv_s4 = {

• .read = meson_s4_rng_read,

+};

• static const struct udevice_id meson_rng_match[] = { { .compatible = "amlogic,meson-rng",

• .data = (ulong)&meson_rng_priv,
  

• },
• {

• .compatible = "amlogic,meson-s4-rng",
  

• .data = (ulong)&meson_rng_priv_s4,
  

  }, {}, };

I get: +drivers/rng/meson-rng.c: In function 'meson_rng_probe': +drivers/rng/meson-rng.c:117:21: error: assignment to 'struct meson_rng_priv *' from 'ulong' {aka 'long unsigned int'} makes pointer from integer without a cast [-Werror=int-conversion] + 117 | pdata->priv = dev_get_driver_data(dev);

while building in CI.

Thanks, Neil