On 2/21/19 10:43 PM, Simon Goldschmidt wrote:
> This adds code to take peripherals out of reset based on an environment
> variable. This is in preparation for removing the code that does this from
> SPL.
>
> However, some drivers even in current Linux cannot handle peripheral reset,
> so until this works, we need a compatibility workaround.
>
> This workaround is implemented in the 'remove' callback of this reset
> driver, which is called on OS_PREPARE: it checks if the environment
> variable "socfpga_permodrst_ungate" - if it is set to 1, it deasserts all
> peripheral resets, which is what the gen5 SPL did up to now.
>
> This is in preparation to clean up the SPL and implementing proper reset
> handling for U-Boot.
>
> Signed-off-by: Simon Goldschmidt <simon.k.r.goldschm...@gmail.com>
> ---
>
> Changes in v2:
> - moved from Kernel option "OLD_SOCFPGA_KERNEL_COMPAT" to environment
> variable "socfpga_permodrst_ungate"
>
> drivers/reset/reset-socfpga.c | 34 ++++++++++++++++++++++++++++++++++
> 1 file changed, 34 insertions(+)
>
> diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c
> index b2acfcd2ec..749f671e05 100644
> --- a/drivers/reset/reset-socfpga.c
> +++ b/drivers/reset/reset-socfpga.c
> @@ -89,6 +89,36 @@ static int socfpga_reset_probe(struct udevice *dev)
> return 0;
> }
>
> +#ifndef CONFIG_SPL_BUILD
> +/*
> + * This remove function is called before starting OS to deassert peripheral
> + * resets for Kernels that don't support this.
> + *
> + * The reset driver checks the environment variable
> "socfpga_permodrst_ungate"
> + * when it is removed. If this variable is '1', all peripherals in
> 'permodrst'
> + * are taken out of reset before booting into the OS.
> + * This should be required for gen5 systems only that are running Linux
> kernels
> + * without proper peripheral reset support for all drivers used.
> + */
> +static int socfpga_reset_remove(struct udevice *dev)
> +{
> + struct socfpga_reset_data *data = dev_get_priv(dev);
> + const char *env_str;
> + long val;
> +
> + env_str = env_get("socfpga_permodrst_ungate");
> + if (env_str) {
> + val = simple_strtol(env_str, NULL, 0);
> + if (val == 1) {
> + puts("Deasserting all peripheral resets\n");
> + writel(0, data->membase + 4);
> + }
> + }
> +
> + return 0;
> +}
> +#endif
> +
> static const struct udevice_id socfpga_reset_match[] = {
> { .compatible = "altr,rst-mgr" },
> { /* sentinel */ },
> @@ -101,4 +131,8 @@ U_BOOT_DRIVER(socfpga_reset) = {
> .probe = socfpga_reset_probe,
> .priv_auto_alloc_size = sizeof(struct socfpga_reset_data),
> .ops = &socfpga_reset_ops,
> +#ifndef CONFIG_SPL_BUILD
> + .remove = socfpga_reset_remove,
> + .flags = DM_FLAG_OS_PREPARE,
> +#endif
> };
Does this work if you use Falcon mode ? :)
--
Best regards,
Marek Vasut
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