Commit 26b754f9 authored by Fabio Estevam's avatar Fabio Estevam Committed by Shawn Guo
Browse files

ARM: mx5: Set the DBGEN bit in ARM_GPC register 



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: default avatarFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: default avatarShawn Guo <shawnguo@kernel.org>
parent 11d973de

arch/arm/mach-imx/common.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

arch/arm/mach-imx/cpu-imx5.c

+45 −0
Original line number Diff line number Diff line
@@ -117,3 +117,48 @@ 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;



	of_node_put(np);



	np = of_find_compatible_node(NULL, NULL, "fsl,imx51-tigerp");

	if (!np)

		return;



	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);



}

arch/arm/mach-imx/mach-imx51.c

+1 −0
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ static void __init imx51_dt_init(void) 
	imx51_ipu_mipi_setup();

	imx_src_init();

	imx51_m4if_setup();

	imx5_pmu_init();

	imx_aips_allow_unprivileged_access("fsl,imx51-aipstz");

}

arch/arm/mach-imx/mach-imx53.c

+1 −1
Original line number Diff line number Diff line
@@ -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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