[PATCH 0/3] ARM: brcmstb: Bus Interface Unit support

[PATCH 0/3] ARM: brcmstb: Bus Interface Unit support

[Florian Fainelli]

Hi all,

This patch series adds support for early boot time Bus Interface Unit control
register setup which is required to occur before SMP is brought-up, but needs
to remap registers, so init_irq() is chosen for that.

This builds on top of the 'soc/next' branch at github.com/Broadcom/stblinux

Thanks!

Florian Fainelli (3):
  Documentation: bindings: brcmstb: Document write-pairing
  soc: brcmstb: Add Bus Interface Unit control setup
  ARM: brcmstb: Setup BIU control registers during boot

 .../devicetree/bindings/arm/bcm/brcm,brcmstb.txt   |  15 +++
 arch/arm/mach-bcm/brcmstb.c                        |   9 ++
 drivers/soc/brcmstb/Makefile                       |   2 +-
 drivers/soc/brcmstb/biuctrl.c                      | 117 +++++++++++++++++++++
 include/linux/soc/brcmstb/brcmstb.h                |  10 ++
 5 files changed, 152 insertions(+), 1 deletion(-)
 create mode 100644 drivers/soc/brcmstb/biuctrl.c
 create mode 100644 include/linux/soc/brcmstb/brcmstb.h

-- 
2.1.0

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[PATCH 1/3] Documentation: bindings: brcmstb: Document write-pairing

[Florian Fainelli]

Document the hif-cpubiuctrl node a bit more, and add a documentation
entry for the optional "brcm,write-pairing" property.

Signed-off-by: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 .../devicetree/bindings/arm/bcm/brcm,brcmstb.txt          | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt b/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt
index 430608ec09f0..602fa5f308bb 100644
--- a/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt
+++ b/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt
@@ -20,6 +20,20 @@ system control is required:
     - compatible: "brcm,bcm<chip_id>-hif-cpubiuctrl", "syscon"
     - compatible: "brcm,bcm<chip_id>-hif-continuation", "syscon"
 
+hif-cpubiuctrl node
+-------------------
+
+Required properties:
+
+    - compatible
+	The string should be "brcm.bcm7445-hif-cpubiuctrl", "syscon"
+
+Optional properties:
+
+    - brcm,write-pairing:
+	Boolean property, which when present indicatse that the chip
+	supports write-pairing.
+
 example:
     rdb {
         #address-cells = <1>;
@@ -35,6 +49,7 @@ example:
         hif_cpubiuctrl: syscon@3e2400 {
             compatible = "brcm,bcm7445-hif-cpubiuctrl", "syscon";
             reg = <0x3e2400 0x5b4>;
+            brcm,write-pairing;
         };
 
         hif_continuation: syscon@452000 {
-- 
2.1.0

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Re: [PATCH 1/3] Documentation: bindings: brcmstb: Document write-pairing

[Rob Herring]

On 09/14/2015 02:52 PM, Florian Fainelli wrote:
> Document the hif-cpubiuctrl node a bit more, and add a documentation
> entry for the optional "brcm,write-pairing" property.
> 
> Signed-off-by: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>  .../devicetree/bindings/arm/bcm/brcm,brcmstb.txt          | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt b/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt
> index 430608ec09f0..602fa5f308bb 100644
> --- a/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt
> +++ b/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt
> @@ -20,6 +20,20 @@ system control is required:
>      - compatible: "brcm,bcm<chip_id>-hif-cpubiuctrl", "syscon"

This has multiple chips allowed, but...

>      - compatible: "brcm,bcm<chip_id>-hif-continuation", "syscon"
>  
> +hif-cpubiuctrl node
> +-------------------

Perhaps it is outside this context, but a description of the block would
be nice.

> +
> +Required properties:
> +
> +    - compatible
> +	The string should be "brcm.bcm7445-hif-cpubiuctrl", "syscon"

This is just one.

> +
> +Optional properties:
> +
> +    - brcm,write-pairing:
> +	Boolean property, which when present indicatse that the chip

s/indicatse/indicates/

> +	supports write-pairing.

What is write pairing? Please give brief description.

> +
>  example:
>      rdb {
>          #address-cells = <1>;
> @@ -35,6 +49,7 @@ example:
>          hif_cpubiuctrl: syscon@3e2400 {
>              compatible = "brcm,bcm7445-hif-cpubiuctrl", "syscon";
>              reg = <0x3e2400 0x5b4>;
> +            brcm,write-pairing;
>          };
>  
>          hif_continuation: syscon@452000 {
> 

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Re: [PATCH 1/3] Documentation: bindings: brcmstb: Document write-pairing

[Florian Fainelli]

On 14/09/15 13:36, Rob Herring wrote:
> On 09/14/2015 02:52 PM, Florian Fainelli wrote:
>> Document the hif-cpubiuctrl node a bit more, and add a documentation
>> entry for the optional "brcm,write-pairing" property.
>>
>> Signed-off-by: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> ---
>>  .../devicetree/bindings/arm/bcm/brcm,brcmstb.txt          | 15 +++++++++++++++
>>  1 file changed, 15 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt b/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt
>> index 430608ec09f0..602fa5f308bb 100644
>> --- a/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt
>> +++ b/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt
>> @@ -20,6 +20,20 @@ system control is required:
>>      - compatible: "brcm,bcm<chip_id>-hif-cpubiuctrl", "syscon"
> 
> This has multiple chips allowed, but...
> 
>>      - compatible: "brcm,bcm<chip_id>-hif-continuation", "syscon"
>>  
>> +hif-cpubiuctrl node
>> +-------------------
> 
> Perhaps it is outside this context, but a description of the block would
> be nice.

Sure.

> 
>> +
>> +Required properties:
>> +
>> +    - compatible
>> +	The string should be "brcm.bcm7445-hif-cpubiuctrl", "syscon"
> 
> This is just one.

Right, will fix that.

> 
>> +
>> +Optional properties:
>> +
>> +    - brcm,write-pairing:
>> +	Boolean property, which when present indicatse that the chip
> 
> s/indicatse/indicates/
> 
>> +	supports write-pairing.
> 
> What is write pairing? Please give brief description.

I will provide an explanation in v2 for what that is.
-- 
Florian
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[PATCH 2/3] soc: brcmstb: Add Bus Interface Unit control setup

[Florian Fainelli]

Broadcom STB SoCs (brcmstb) require an early setup of their Bus
Interface Unit control register, this needs to happen before SMP is
brought up because it affects how the CPU complex will be interfaced to
the memory controller.

Add support code which properly initializes the BIU registers based on
whether "brcm,write-pairing" is present in Device Tree, and take care of
saving and restoring credit register settings during system-wide
suspend/resume operations.

Signed-off-by: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 drivers/soc/brcmstb/Makefile        |   2 +-
 drivers/soc/brcmstb/biuctrl.c       | 117 ++++++++++++++++++++++++++++++++++++
 include/linux/soc/brcmstb/brcmstb.h |  10 +++
 3 files changed, 128 insertions(+), 1 deletion(-)
 create mode 100644 drivers/soc/brcmstb/biuctrl.c
 create mode 100644 include/linux/soc/brcmstb/brcmstb.h

diff --git a/drivers/soc/brcmstb/Makefile b/drivers/soc/brcmstb/Makefile
index 677e3fa0d042..75df0e0c091d 100644
--- a/drivers/soc/brcmstb/Makefile
+++ b/drivers/soc/brcmstb/Makefile
@@ -1,3 +1,3 @@
 obj-$(CONFIG_BRCMSTB_PM)	+= pm/
 
-obj-y				+= common.o
+obj-y				+= common.o biuctrl.o
diff --git a/drivers/soc/brcmstb/biuctrl.c b/drivers/soc/brcmstb/biuctrl.c
new file mode 100644
index 000000000000..7e4ead2c9565
--- /dev/null
+++ b/drivers/soc/brcmstb/biuctrl.c
@@ -0,0 +1,117 @@
+/*
+ * Broadcom STB SoCs Bus Unit Interface controls
+ *
+ * Copyright (C) 2015, Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/syscore_ops.h>
+
+#define CPU_CREDIT_REG_OFFSET			0x184
+#define  CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK	0x70000000
+
+static void __iomem *cpubiuctrl_base;
+static bool mcp_wr_pairing_en;
+
+static int __init mcp_write_pairing_set(void)
+{
+	u32 creds = 0;
+
+	if (!cpubiuctrl_base)
+		return -1;
+
+	creds = readl_relaxed(cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
+	if (mcp_wr_pairing_en) {
+		pr_info("MCP: Enabling write pairing\n");
+		writel_relaxed(creds | CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK,
+			     cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
+	} else if (creds & CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK) {
+		pr_info("MCP: Disabling write pairing\n");
+		writel_relaxed(creds & ~CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK,
+				cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
+	} else {
+		pr_info("MCP: Write pairing already disabled\n");
+	}
+
+	return 0;
+}
+
+static int __init setup_hifcpubiuctrl_regs(void)
+{
+	struct device_node *np;
+	int ret = 0;
+
+	np = of_find_compatible_node(NULL, NULL, "brcm,brcmstb-cpu-biu-ctrl");
+	if (!np) {
+		pr_err("missing BIU control node\n");
+		return -ENODEV;
+	}
+
+	cpubiuctrl_base = of_iomap(np, 0);
+	if (!cpubiuctrl_base) {
+		pr_err("failed to remap BIU control base\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	mcp_wr_pairing_en = of_property_read_bool(np, "brcm,write-pairing");
+out:
+	of_node_put(np);
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static u32 cpu_credit_reg_dump;  /* for save/restore */
+
+static int brcmstb_cpu_credit_reg_suspend(void)
+{
+	if (cpubiuctrl_base)
+		cpu_credit_reg_dump =
+			readl_relaxed(cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
+	return 0;
+}
+
+static void brcmstb_cpu_credit_reg_resume(void)
+{
+	if (cpubiuctrl_base)
+		writel_relaxed(cpu_credit_reg_dump,
+				cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
+}
+
+static struct syscore_ops brcmstb_cpu_credit_syscore_ops = {
+	.suspend = brcmstb_cpu_credit_reg_suspend,
+	.resume = brcmstb_cpu_credit_reg_resume,
+};
+#endif
+
+
+int __init brcmstb_biuctrl_init(void)
+{
+	int ret = 0;
+
+	ret = setup_hifcpubiuctrl_regs();
+	if (ret)
+		return ret;
+
+	ret = mcp_write_pairing_set();
+	if (ret) {
+		pr_err("MCP: Unable to disable write pairing!\n");
+		return ret;
+	}
+
+#ifdef CONFIG_PM_SLEEP
+	register_syscore_ops(&brcmstb_cpu_credit_syscore_ops);
+#endif
+	return ret;
+}
diff --git a/include/linux/soc/brcmstb/brcmstb.h b/include/linux/soc/brcmstb/brcmstb.h
new file mode 100644
index 000000000000..7009f61ea24c
--- /dev/null
+++ b/include/linux/soc/brcmstb/brcmstb.h
@@ -0,0 +1,10 @@
+#ifndef __BRCMSTB_SOC_H
+#define __BRCMSTB_SOC_H
+
+/*
+ * Bus Interface Unit control register setup, must happen early during boot,
+ * before SMP is brought up, called by machine entry point.
+ */
+int brcmstb_biuctrl_init(void);
+
+#endif /* __BRCMSTB_SOC_H */
-- 
2.1.0

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[PATCH 3/3] ARM: brcmstb: Setup BIU control registers during boot

[Florian Fainelli]

Call brcmstb_biuctrl_init() in brcmstb's init_irq machine descriptor
callback since we need to setup the Bus Interface Unit before SMP in
particular, but we also need to be able to remap registers.

Signed-off-by: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 arch/arm/mach-bcm/brcmstb.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/mach-bcm/brcmstb.c b/arch/arm/mach-bcm/brcmstb.c
index 3a60f7ee3f0c..99a67cfb7c0d 100644
--- a/arch/arm/mach-bcm/brcmstb.c
+++ b/arch/arm/mach-bcm/brcmstb.c
@@ -12,11 +12,19 @@
  */
 
 #include <linux/init.h>
+#include <linux/irqchip.h>
 #include <linux/of_platform.h>
+#include <linux/soc/brcmstb/brcmstb.h>
 
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
 
+static void __init brcmstb_init_irq(void)
+{
+	irqchip_init();
+	brcmstb_biuctrl_init();
+}
+
 static const char *const brcmstb_match[] __initconst = {
 	"brcm,bcm7445",
 	"brcm,brcmstb",
@@ -25,4 +33,5 @@ static const char *const brcmstb_match[] __initconst = {
 
 DT_MACHINE_START(BRCMSTB, "Broadcom STB (Flattened Device Tree)")
 	.dt_compat	= brcmstb_match,
+	.init_irq	= brcmstb_init_irq,
 MACHINE_END
-- 
2.1.0

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Re: [PATCH 3/3] ARM: brcmstb: Setup BIU control registers during boot

[Brian Norris]

On Mon, Sep 14, 2015 at 12:52:49PM -0700, Florian Fainelli wrote:
> Call brcmstb_biuctrl_init() in brcmstb's init_irq machine descriptor
> callback since we need to setup the Bus Interface Unit before SMP in
> particular, but we also need to be able to remap registers.
> 
> Signed-off-by: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>  arch/arm/mach-bcm/brcmstb.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/arm/mach-bcm/brcmstb.c b/arch/arm/mach-bcm/brcmstb.c
> index 3a60f7ee3f0c..99a67cfb7c0d 100644
> --- a/arch/arm/mach-bcm/brcmstb.c
> +++ b/arch/arm/mach-bcm/brcmstb.c
> @@ -12,11 +12,19 @@
>   */
>  
>  #include <linux/init.h>
> +#include <linux/irqchip.h>
>  #include <linux/of_platform.h>
> +#include <linux/soc/brcmstb/brcmstb.h>
>  
>  #include <asm/mach-types.h>
>  #include <asm/mach/arch.h>
>  
> +static void __init brcmstb_init_irq(void)
> +{
> +	irqchip_init();
> +	brcmstb_biuctrl_init();

I believe you're introducing a dependency on CONFIG_SOC_BRCMSTB, but
it's not represented in Kconfig. Maybe SOC_BRCMSTB shouldn't be
user-selectable, and it should just be select-ed by ARCH_BRCMSTB?

Brian

> +}
> +
>  static const char *const brcmstb_match[] __initconst = {
>  	"brcm,bcm7445",
>  	"brcm,brcmstb",
> @@ -25,4 +33,5 @@ static const char *const brcmstb_match[] __initconst = {
>  
>  DT_MACHINE_START(BRCMSTB, "Broadcom STB (Flattened Device Tree)")
>  	.dt_compat	= brcmstb_match,
> +	.init_irq	= brcmstb_init_irq,
>  MACHINE_END
> -- 
> 2.1.0
> 
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Re: [PATCH 3/3] ARM: brcmstb: Setup BIU control registers during boot

[Florian Fainelli]

On 14/09/15 13:48, Brian Norris wrote:
> On Mon, Sep 14, 2015 at 12:52:49PM -0700, Florian Fainelli wrote:
>> Call brcmstb_biuctrl_init() in brcmstb's init_irq machine descriptor
>> callback since we need to setup the Bus Interface Unit before SMP in
>> particular, but we also need to be able to remap registers.
>>
>> Signed-off-by: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> ---
>> +static void __init brcmstb_init_irq(void)
>> +{
>> +	irqchip_init();
>> +	brcmstb_biuctrl_init();
> 
> I believe you're introducing a dependency on CONFIG_SOC_BRCMSTB, but
> it's not represented in Kconfig. Maybe SOC_BRCMSTB shouldn't be
> user-selectable, and it should just be select-ed by ARCH_BRCMSTB?

It is thanks to your previous commit, which is why I mentioned in the
cover letter that this was based on the 'soc/next' branch.

https://github.com/Broadcom/stblinux/commit/b19826efa15f94084416d5fc7749c45eabfbee36

Thanks for taking a look though!
-- 
Florian
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Re: [PATCH 3/3] ARM: brcmstb: Setup BIU control registers during boot

[Brian Norris]

On Mon, Sep 14, 2015 at 02:21:11PM -0700, Florian Fainelli wrote:
> On 14/09/15 13:48, Brian Norris wrote:
> > On Mon, Sep 14, 2015 at 12:52:49PM -0700, Florian Fainelli wrote:
> >> Call brcmstb_biuctrl_init() in brcmstb's init_irq machine descriptor
> >> callback since we need to setup the Bus Interface Unit before SMP in
> >> particular, but we also need to be able to remap registers.
> >>
> >> Signed-off-by: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> >> ---
> >> +static void __init brcmstb_init_irq(void)
> >> +{
> >> +	irqchip_init();
> >> +	brcmstb_biuctrl_init();
> > 
> > I believe you're introducing a dependency on CONFIG_SOC_BRCMSTB, but
> > it's not represented in Kconfig. Maybe SOC_BRCMSTB shouldn't be
> > user-selectable, and it should just be select-ed by ARCH_BRCMSTB?
> 
> It is thanks to your previous commit, which is why I mentioned in the
> cover letter that this was based on the 'soc/next' branch.
> 
> https://github.com/Broadcom/stblinux/commit/b19826efa15f94084416d5fc7749c45eabfbee36

Hah, bad memory I have. I suppose a user-selectable option that is also
selected by another symbol is OK if the former has few/no dependencies.

> Thanks for taking a look though!

Brian
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