[PATCH 2/3] arm64: dts: juno: add arm, primecell-periphid override
From: liviu.dudau@arm.com (Liviu Dudau)
Date: 2016-06-08 16:05:17
Also in:
linux-devicetree
On Mon, Jun 06, 2016 at 04:59:24PM +0100, Sudeep Holla wrote:
The Linux AMBA framework probes the peripheral ids when adding the amba devices very early on the boot. Generally they are on APB bus and just require APB clocks to be on even when most of the core logic of the IP is powered down. However on Juno, the entire debugsys domain needs to be ON to access those CID/PID registers and hence broken by design. Accessing those while debugsys power domain is off will lead to the bridge stalling the transactions instead of returning the slave error. Since keeping the power domain on by default affects the core power(by preventing cores entering deeper idle states), it's not feasible solution. Instead we can provide arm,primecell-periphid override in the device tree that prevents accessing the device early in the boot. However the power domains can be enabled whenever required using runtime PM and associated power domains. Cc: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
quoted hunk
Cc: Lorenzo Pieralisi <redacted> Cc: linux-arm-kernel at lists.infradead.org Cc: devicetree at vger.kernel.org Signed-off-by: Sudeep Holla <redacted> --- arch/arm64/boot/dts/arm/juno-base.dtsi | 13 +++++++++++++ arch/arm64/boot/dts/arm/juno-r1.dts | 6 ++++++ arch/arm64/boot/dts/arm/juno-r2.dts | 6 ++++++ arch/arm64/boot/dts/arm/juno.dts | 6 ++++++ 4 files changed, 31 insertions(+)diff --git a/arch/arm64/boot/dts/arm/juno-base.dtsi b/arch/arm64/boot/dts/arm/juno-base.dtsi index 90a8710f7032..49fa55cdc977 100644 --- a/arch/arm64/boot/dts/arm/juno-base.dtsi +++ b/arch/arm64/boot/dts/arm/juno-base.dtsi@@ -63,6 +63,14 @@ */ etf at 20010000 { compatible = "arm,coresight-tmc", "arm,primecell"; + /* + * The primecell peripheral id is explicitly specified here with + * the actual hardware value. It's not any override. It's + * required to workaround an errata to avoid bus stalls early + * in the boot when AMBA primecell ids are probed before the + * actual power domain can be enabled using SCPI. + */ + arm,primecell-periphid = <0x001bb961>; reg = <0 0x20010000 0 0x1000>; clocks = <&soc_smc50mhz>;@@ -92,6 +100,7 @@ tpiu at 20030000 { compatible = "arm,coresight-tpiu", "arm,primecell"; + arm,primecell-periphid = <0x004bb912>; reg = <0 0x20030000 0 0x1000>; clocks = <&soc_smc50mhz>;@@ -106,6 +115,7 @@ main_funnel at 20040000 { compatible = "arm,coresight-funnel", "arm,primecell"; + arm,primecell-periphid = <0x002bb908>; reg = <0 0x20040000 0 0x1000>; clocks = <&soc_smc50mhz>;@@ -142,6 +152,7 @@ etr at 20070000 { compatible = "arm,coresight-tmc", "arm,primecell"; + arm,primecell-periphid = <0x001bb961>; reg = <0 0x20070000 0 0x1000>; clocks = <&soc_smc50mhz>;@@ -192,6 +203,7 @@ cluster0_funnel at 220c0000 { compatible = "arm,coresight-funnel", "arm,primecell"; + arm,primecell-periphid = <0x002bb908>; reg = <0 0x220c0000 0 0x1000>; clocks = <&soc_smc50mhz>;@@ -227,6 +239,7 @@ cluster1_funnel at 230c0000 { compatible = "arm,coresight-funnel", "arm,primecell"; + arm,primecell-periphid = <0x002bb908>; reg = <0 0x230c0000 0 0x1000>; clocks = <&soc_smc50mhz>;diff --git a/arch/arm64/boot/dts/arm/juno-r1.dts b/arch/arm64/boot/dts/arm/juno-r1.dts index f4f8f54f8b85..c3c9fdff49bf 100644 --- a/arch/arm64/boot/dts/arm/juno-r1.dts +++ b/arch/arm64/boot/dts/arm/juno-r1.dts@@ -184,24 +184,30 @@ &etm0 { cpu = <&A57_0>; + arm,primecell-periphid = <0x002bb95e>; }; &etm1 { cpu = <&A57_1>; + arm,primecell-periphid = <0x002bb95e>; }; &etm2 { cpu = <&A53_0>; + arm,primecell-periphid = <0x003bb95d>; }; &etm3 { cpu = <&A53_1>; + arm,primecell-periphid = <0x003bb95d>; }; &etm4 { cpu = <&A53_2>; + arm,primecell-periphid = <0x003bb95d>; }; &etm5 { cpu = <&A53_3>; + arm,primecell-periphid = <0x003bb95d>; };diff --git a/arch/arm64/boot/dts/arm/juno-r2.dts b/arch/arm64/boot/dts/arm/juno-r2.dts index d903e545b64c..c672c978f89d 100644 --- a/arch/arm64/boot/dts/arm/juno-r2.dts +++ b/arch/arm64/boot/dts/arm/juno-r2.dts@@ -184,24 +184,30 @@ &etm0 { cpu = <&A72_0>; + arm,primecell-periphid = <0x000bb95a>; }; &etm1 { cpu = <&A72_1>; + arm,primecell-periphid = <0x000bb95a>; }; &etm2 { cpu = <&A53_0>; + arm,primecell-periphid = <0x003bb95d>; }; &etm3 { cpu = <&A53_1>; + arm,primecell-periphid = <0x003bb95d>; }; &etm4 { cpu = <&A53_2>; + arm,primecell-periphid = <0x003bb95d>; }; &etm5 { cpu = <&A53_3>; + arm,primecell-periphid = <0x003bb95d>; };diff --git a/arch/arm64/boot/dts/arm/juno.dts b/arch/arm64/boot/dts/arm/juno.dts index a7270eff6939..0528e47e66d1 100644 --- a/arch/arm64/boot/dts/arm/juno.dts +++ b/arch/arm64/boot/dts/arm/juno.dts@@ -176,24 +176,30 @@ &etm0 { cpu = <&A57_0>; + arm,primecell-periphid = <0x000bb95e>; }; &etm1 { cpu = <&A57_1>; + arm,primecell-periphid = <0x000bb95e>; }; &etm2 { cpu = <&A53_0>; + arm,primecell-periphid = <0x000bb95d>; }; &etm3 { cpu = <&A53_1>; + arm,primecell-periphid = <0x000bb95d>; }; &etm4 { cpu = <&A53_2>; + arm,primecell-periphid = <0x000bb95d>; }; &etm5 { cpu = <&A53_3>; + arm,primecell-periphid = <0x000bb95d>; }; --2.7.4
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