[PATCH v2 2/2] ARM: imx53: globally disable supervisor protect
Shawn Guo
shawn.guo at freescale.com
Sun Jun 29 21:12:27 PDT 2014
On Wed, Jun 25, 2014 at 01:01:31PM +0200, Steffen Trumtrar wrote:
> Most peripherals on the i.MX53 have an
> Off-Platform Peripheral Access Control Register (OPACR)
> in which the access rights (together with the MPROT registers) can be declared.
> However, this does not seem to work for example for SSI1+SDMA, because the
> supervisor bit is not set for the SDMA unit.
> It does work for SSI2, the QSB for example uses SSI2 for its audio. But SSI2 only
> works because it does NOT have an OPACR.
>
> The right solution would be to fix the access rights for the SDMA, but the unit
> responsible for this is the Central Security Unit (CSU), which of course is NOT
> documented. So, until documentation for this is openly available, turn off the
> supervisor protection because it cripples the hardware.
>
> Signed-off-by: Steffen Trumtrar <s.trumtrar at pengutronix.de>
> ---
> arch/arm/mach-imx/mach-imx53.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/arch/arm/mach-imx/mach-imx53.c b/arch/arm/mach-imx/mach-imx53.c
> index 2bad387..380c7ee 100644
> --- a/arch/arm/mach-imx/mach-imx53.c
> +++ b/arch/arm/mach-imx/mach-imx53.c
> @@ -15,6 +15,7 @@
> #include <linux/err.h>
> #include <linux/io.h>
> #include <linux/irq.h>
> +#include <linux/of_address.h>
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> #include <asm/mach/arch.h>
> @@ -24,11 +25,24 @@
> #include "hardware.h"
> #include "mx53.h"
>
> +static const struct of_device_id aips_of_matches[] __initconst = {
> + { .compatible = "fsl,imx53-aipstz" },
> + { /*sentinel*/ }
> +};
> +
> static void __init imx53_dt_init(void)
> {
> + void __iomem *aips_base_addr;
> + struct device_node *np;
> +
> mxc_arch_reset_init_dt();
>
> of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
> +
> + for_each_matching_node(np, aips_of_matches) {
> + aips_base_addr = of_iomap(np, 0);
> + imx_set_aips(aips_base_addr);
> + }
The same code pattern might be needed for i.MX31 and i.MX35 device tree
support later. Can we have a helper for it, so that i.MX3 DT conversion
can benefit from it?
Shawn
> }
>
> static const char *imx53_dt_board_compat[] __initconst = {
> --
> 2.0.0
>
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