Am Do., 21. Feb. 2019, 22:56 hat Marek Vasut marex@denx.de geschrieben:
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.goldschmidt@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 ? :)
Probably not, but would anyone be able to use falcon mode in socfpga gen5 given the current SPL size? I think it didn't fit for,a last time I checked.
And if it fits in the future, we probably don't need this workaraound any more...
I did it like that since env_get() broke compilation of SPL. But if you insist of making this work even for SPL, I'll check again.
Regards, Simon