Hi,
On Tue, Jul 10, 2018 at 01:08:47PM -0300, Fabio Estevam wrote:
> On i.MX51/i.MX53 it is necessary to set the DBGEN bit in
> ARM_GPC register in order to turn on the debug clocks.
>
> The DBGEN bit of ARM_GPC register has the following description
> in the i.MX53 Reference Manual:
>
> "This allows the user to manually activate clocks within the debug
> system. This register bit directly controls the platform's dbgen_out
> output signal which connects to the DAP_SYS to enable all debug clocks.
> Once enabled, the clocks cannot be disabled except by asserting the
> disable_trace input of the DAP_SYS."
>
> Based on a previous patch from Sebastian Reichel.
>
> Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxx>
> ---
> Changes since v2:
> - Also check for "secure-reg-access" presence (Sebastian)
> - Call of_node_put() (Sebastian)
>
> arch/arm/mach-imx/common.h | 1 +
> arch/arm/mach-imx/cpu-imx5.c | 43 ++++++++++++++++++++++++++++++++++++++++++
> arch/arm/mach-imx/mach-imx51.c | 2 +-
> arch/arm/mach-imx/mach-imx53.c | 2 +-
> 4 files changed, 46 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h
> index 93225db7..423dd76 100644
> --- a/arch/arm/mach-imx/common.h
> +++ b/arch/arm/mach-imx/common.h
> @@ -62,6 +62,7 @@ void imx_gpc_set_arm_power_up_timing(u32 sw2iso, u32 sw);
> void imx_gpc_set_arm_power_down_timing(u32 sw2iso, u32 sw);
> void imx25_pm_init(void);
> void imx27_pm_init(void);
> +void imx5_pmu_init(void);
>
> enum mxc_cpu_pwr_mode {
> WAIT_CLOCKED, /* wfi only */
> diff --git a/arch/arm/mach-imx/cpu-imx5.c b/arch/arm/mach-imx/cpu-imx5.c
> index 4f2d1c7..bba6e9b 100644
> --- a/arch/arm/mach-imx/cpu-imx5.c
> +++ b/arch/arm/mach-imx/cpu-imx5.c
> @@ -117,3 +117,46 @@ int mx53_revision(void)
> return mx5_cpu_rev;
> }
> EXPORT_SYMBOL(mx53_revision);
> +
> +#define ARM_GPC 0x4
> +#define DBGEN BIT(16)
> +
> +/*
> + * This enables the DBGEN bit in ARM_GPC register, which is
> + * required for accessing some performance counter features.
> + * Technically it is only required while perf is used, but to
> + * keep the source code simple we just enable it all the time
> + * when the kernel configuration allows using the feature.
> + */
> +void __init imx5_pmu_init(void)
> +{
> + void __iomem *tigerp_base;
> + struct device_node *np;
> + u32 gpc;
> +
> + if (!IS_ENABLED(CONFIG_ARM_PMU))
> + return;
> +
> + np = of_find_compatible_node(NULL, NULL, "arm,cortex-a8-pmu");
> + if (!np)
> + return;
> +
> + if (!of_property_read_bool(np, "secure-reg-access"))
> + goto exit;
There is still a missing of_node_put() here. Otherwise
Reviewed-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxxxx>
> + np = of_find_compatible_node(NULL, NULL, "fsl,imx51-tigerp");
> + if (!np)
> + goto exit;
> +
> + tigerp_base = of_iomap(np, 0);
> + if (!tigerp_base)
> + goto exit;
> +
> + gpc = readl_relaxed(tigerp_base + ARM_GPC);
> + gpc |= DBGEN;
> + writel_relaxed(gpc, tigerp_base + ARM_GPC);
> + iounmap(tigerp_base);
> +exit:
> + of_node_put(np);
> +
> +}
> diff --git a/arch/arm/mach-imx/mach-imx51.c b/arch/arm/mach-imx/mach-imx51.c
> index 3835b6a..8838fba 100644
> --- a/arch/arm/mach-imx/mach-imx51.c
> +++ b/arch/arm/mach-imx/mach-imx51.c
> @@ -52,7 +52,7 @@ static void __init imx51_dt_init(void)
> {
> imx51_ipu_mipi_setup();
> imx_src_init();
> -
> + imx5_pmu_init();
> imx_aips_allow_unprivileged_access("fsl,imx51-aipstz");
> }
>
> diff --git a/arch/arm/mach-imx/mach-imx53.c b/arch/arm/mach-imx/mach-imx53.c
> index 07c2e8d..5ec7100 100644
> --- a/arch/arm/mach-imx/mach-imx53.c
> +++ b/arch/arm/mach-imx/mach-imx53.c
> @@ -31,7 +31,7 @@ static void __init imx53_init_early(void)
> static void __init imx53_dt_init(void)
> {
> imx_src_init();
> -
> + imx5_pmu_init();
> imx_aips_allow_unprivileged_access("fsl,imx53-aipstz");
> }
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