[PATCH v3 0/3] clk: clock driver for the Marvell Armada AP806

[PATCH v3 0/3] clk: clock driver for the Marvell Armada AP806

[Thomas Petazzoni]

Michael, Stephen,

Here is a new version of the clock driver and its DT binding for the
Marvell Armada AP806. As you will see, there is no longer any
reference to the DFX Server and changes in the clock tree compared to
the v2. This is due to the fact that the HW has changed from this
point of view between the test chips and the final revision, and this
new version aims at supporting only the final revision.

We therefore have a very simple DT binding, with one single node that
covers the entire "system controller" registers, associated to one
driver that provides the clocks. This system controller will later be
used to support other features such as pin-muxing, but for now we only
support the clocks aspects of it.

Please let me know if this approach works for you.

Note that this patch series is based on clk-net, because I wanted to
avoid introducing a new use of CLK_IS_ROOT. To do this, I needed the
patches currently in clk-next that remove the need for CLK_IS_ROOT.

Thanks!

Thomas

Thomas Petazzoni (3):
  dt-bindings: arm: add DT binding for Marvell AP806 system controller
  clk: unconditionally recurse into clk/mvebu/
  clk: mvebu: new driver for Armada AP806 system controller

 .../arm/marvell/ap806-system-controller.txt        |  34 +++++++
 drivers/clk/Makefile                               |   2 +-
 drivers/clk/mvebu/Kconfig                          |   3 +
 drivers/clk/mvebu/Makefile                         |   1 +
 drivers/clk/mvebu/ap806-system-controller.c        | 106 +++++++++++++++++++++
 5 files changed, 145 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/arm/marvell/ap806-system-controller.txt
 create mode 100644 drivers/clk/mvebu/ap806-system-controller.c

-- 
2.6.4

[PATCH v3 1/3] dt-bindings: arm: add DT binding for Marvell AP806 system controller

[Thomas Petazzoni]

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 .../arm/marvell/ap806-system-controller.txt        | 34 ++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/marvell/ap806-system-controller.txt

diff --git a/Documentation/devicetree/bindings/arm/marvell/ap806-system-controller.txt b/Documentation/devicetree/bindings/arm/marvell/ap806-system-controller.txt
new file mode 100644
index 0000000..5086b89
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/marvell/ap806-system-controller.txt
@@ -0,0 +1,34 @@
+Marvell Armada AP806 System Controller
+======================================
+
+The AP806 is one of the two core HW blocks of the Marvell Armada 7K/8K
+SoCs. It contains a system controller, which provides a number
+registers giving access to numerous features: clocks, pin-muxing and
+many other SoC configuration items. This DT binding allows to describe
+this system controller.
+
+The Device Tree node representing the AP806 system controller provides
+a number of clocks:
+
+ - 0: clock of CPU cluster 0
+ - 1: clock of CPU cluster 1
+ - 2: fixed PLL at 1200 Mhz
+ - 3: MSS clock, derived from the fixed PLL
+
+Required properties:
+
+ - compatible: must be:
+     "marvell,ap806-system-controller", "syscon"
+ - reg: register area of the AP806 system controller
+ - #clock-cells: must be set to 1
+ - clock-output-names: must be defined to:
+    "cpu-cluster-0", "cpu-cluster-1", "fixed", "mss"
+
+Example:
+
+	syscon: system-controller@6f4000 {
+		compatible = "marvell,ap806-system-controller", "syscon";
+		#clock-cells = <1>;
+		clock-output-names = "cpu-cluster-0", "cpu-cluster-1", "fixed", "mss";
+		reg = <0x6f4000 0x1000>;
+	};
-- 
2.6.4

[PATCH v3 2/3] clk: unconditionally recurse into clk/mvebu/

[Thomas Petazzoni]

The drivers/clk/mvebu directory is only being built when
CONFIG_PLAT_ORION=y. As we are going to support additional mvebu
platforms in drivers/clk/mvebu, which don't have CONFIG_PLAT_ORION=y,
we need to recurse into this directory regardless of the value of
CONFIG_PLAT_ORION.

Since all files in drivers/clk/mvebu/ are already conditionally
compiled depending on various Kconfig options, we can recurse
unconditionally into drivers/clk/mvebu without any other change.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/clk/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 46869d69..f9ad66e 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -61,7 +61,7 @@ obj-$(CONFIG_ARCH_MEDIATEK)		+= mediatek/
 ifeq ($(CONFIG_COMMON_CLK), y)
 obj-$(CONFIG_ARCH_MMP)			+= mmp/
 endif
-obj-$(CONFIG_PLAT_ORION)		+= mvebu/
+obj-y					+= mvebu/
 obj-$(CONFIG_ARCH_MESON)		+= meson/
 obj-$(CONFIG_ARCH_MXS)			+= mxs/
 obj-$(CONFIG_MACH_PISTACHIO)		+= pistachio/
-- 
2.6.4

[PATCH v3 3/3] clk: mvebu: new driver for Armada AP806 system controller

[Thomas Petazzoni]

The Armada AP806 system controller, amongst other things, provides a
number of clocks for the platform: the CPU cluster clocks, whose
frequencies are found by reading the Sample At Reset register, one
fixed clock, and another clock derived from the fixed clock, which is
the one used by most peripherals in AP806.

The AP806 is one of the two core HW blocks used in the Marvell 7K/8K
SoCs.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/clk/mvebu/Kconfig                   |   3 +
 drivers/clk/mvebu/Makefile                  |   1 +
 drivers/clk/mvebu/ap806-system-controller.c | 106 ++++++++++++++++++++++++++++
 3 files changed, 110 insertions(+)
 create mode 100644 drivers/clk/mvebu/ap806-system-controller.c

diff --git a/drivers/clk/mvebu/Kconfig b/drivers/clk/mvebu/Kconfig
index eaee8f0..bf7ae00 100644
--- a/drivers/clk/mvebu/Kconfig
+++ b/drivers/clk/mvebu/Kconfig
@@ -29,6 +29,9 @@ config ARMADA_XP_CLK
 	select MVEBU_CLK_COMMON
 	select MVEBU_CLK_CPU
 
+config ARMADA_AP806_SYSCON
+	bool
+
 config DOVE_CLK
 	bool
 	select MVEBU_CLK_COMMON
diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile
index 8866115..f4aa481 100644
--- a/drivers/clk/mvebu/Makefile
+++ b/drivers/clk/mvebu/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_ARMADA_375_CLK)	+= armada-375.o
 obj-$(CONFIG_ARMADA_38X_CLK)	+= armada-38x.o
 obj-$(CONFIG_ARMADA_39X_CLK)	+= armada-39x.o
 obj-$(CONFIG_ARMADA_XP_CLK)	+= armada-xp.o
+obj-$(CONFIG_ARMADA_AP806_SYSCON) += ap806-system-controller.o
 obj-$(CONFIG_DOVE_CLK)		+= dove.o dove-divider.o
 obj-$(CONFIG_KIRKWOOD_CLK)	+= kirkwood.o
 obj-$(CONFIG_ORION_CLK)		+= orion.o
diff --git a/drivers/clk/mvebu/ap806-system-controller.c b/drivers/clk/mvebu/ap806-system-controller.c
new file mode 100644
index 0000000..c33c209
--- /dev/null
+++ b/drivers/clk/mvebu/ap806-system-controller.c
@@ -0,0 +1,106 @@
+/*
+ * Marvell Armada AP806 System Controller
+ *
+ * Copyright (C) 2016 Marvell
+ *
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#define pr_fmt(fmt) "ap806-system-controller: " fmt
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+
+#define AP806_SAR_REG			0x400
+#define AP806_SAR_CLKFREQ_MODE_MASK	0x1f
+
+#define AP806_CLK_NUM 			4
+
+static struct clk *ap806_clks[AP806_CLK_NUM];
+
+static struct clk_onecell_data ap806_clk_data = {
+	.clks = ap806_clks,
+	.clk_num = AP806_CLK_NUM,
+};
+
+static void __init ap806_syscon_clk_init(struct device_node *np)
+{
+	unsigned int freq_mode, cpuclk_freq;
+	const char *name, *fixedclk_name;
+	struct regmap *regmap;
+	u32 reg;
+
+	regmap = syscon_node_to_regmap(np);
+	if (IS_ERR(regmap)) {
+		pr_err("cannot get regmap\n");
+		return;
+	}
+
+	if (regmap_read(regmap, AP806_SAR_REG, &reg)) {
+		pr_err("cannot read from regmap\n");
+		return;
+	}
+
+	freq_mode = reg & AP806_SAR_CLKFREQ_MODE_MASK;
+	switch(freq_mode) {
+	case 0x0 ... 0x5:
+		cpuclk_freq = 2000;
+		break;
+	case 0x6 ... 0xB:
+		cpuclk_freq = 1800;
+		break;
+	case 0xC ... 0x11:
+		cpuclk_freq = 1600;
+		break;
+	case 0x12 ... 0x16:
+		cpuclk_freq = 1400;
+		break;
+	case 0x17 ... 0x19:
+		cpuclk_freq = 1300;
+		break;
+	default:
+		pr_err("invalid SAR value\n");
+		return;
+	}
+
+	/* Convert to hertz */
+	cpuclk_freq *= 1000 * 1000;
+
+	/* CPU clocks depend on the Sample At Reset configuration */
+	of_property_read_string_index(np, "clock-output-names",
+				      0, &name);
+	ap806_clks[0] = clk_register_fixed_rate(NULL, name, NULL,
+						0, cpuclk_freq);
+
+	of_property_read_string_index(np, "clock-output-names",
+				      1, &name);
+	ap806_clks[1] = clk_register_fixed_rate(NULL, name, NULL, 0,
+						cpuclk_freq);
+
+	/* Fixed clock is always 1200 Mhz */
+	of_property_read_string_index(np, "clock-output-names",
+				      2, &fixedclk_name);
+	ap806_clks[2] = clk_register_fixed_rate(NULL, fixedclk_name, NULL, 0,
+						1200 * 1000 * 1000);
+
+	/* MSS Clock is fixed clock divided by 6 */
+	of_property_read_string_index(np, "clock-output-names",
+				      3, &name);
+	ap806_clks[3] = clk_register_fixed_factor(NULL, name, fixedclk_name,
+						  0, 1, 6);
+
+	of_clk_add_provider(np, of_clk_src_onecell_get, &ap806_clk_data);
+}
+
+CLK_OF_DECLARE(ap806_syscon_clk, "marvell,ap806-system-controller",
+	       ap806_syscon_clk_init);
-- 
2.6.4

Re: [PATCH v3 1/3] dt-bindings: arm: add DT binding for Marvell AP806 system controller

[Rob Herring]

On Fri, Mar 04, 2016 at 01:57:53PM +0100, Thomas Petazzoni wrote:
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> ---
>  .../arm/marvell/ap806-system-controller.txt        | 34 ++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/marvell/ap806-system-controller.txt

That was fun. ;)

Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
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Re: [PATCH v3 0/3] clk: clock driver for the Marvell Armada AP806

[Gregory CLEMENT]

Hi Thomas,
 
 On ven., mars 04 2016, Thomas Petazzoni <thomas.petazzoni@free-electrons.com> wrote:

> Michael, Stephen,
>
> Here is a new version of the clock driver and its DT binding for the
> Marvell Armada AP806. As you will see, there is no longer any
> reference to the DFX Server and changes in the clock tree compared to
> the v2. This is due to the fact that the HW has changed from this
> point of view between the test chips and the final revision, and this
> new version aims at supporting only the final revision.
>
> We therefore have a very simple DT binding, with one single node that
> covers the entire "system controller" registers, associated to one
> driver that provides the clocks. This system controller will later be
> used to support other features such as pin-muxing, but for now we only
> support the clocks aspects of it.
>
> Please let me know if this approach works for you.
>
> Note that this patch series is based on clk-net, because I wanted to
> avoid introducing a new use of CLK_IS_ROOT. To do this, I needed the
> patches currently in clk-next that remove the need for CLK_IS_ROOT.
>
> Thanks!

The series is clean and small, I didn't see any problem with it, so for
the whole series:

Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

Thanks,

Gregory


>
> Thomas
>
> Thomas Petazzoni (3):
>   dt-bindings: arm: add DT binding for Marvell AP806 system controller
>   clk: unconditionally recurse into clk/mvebu/
>   clk: mvebu: new driver for Armada AP806 system controller
>
>  .../arm/marvell/ap806-system-controller.txt        |  34 +++++++
>  drivers/clk/Makefile                               |   2 +-
>  drivers/clk/mvebu/Kconfig                          |   3 +
>  drivers/clk/mvebu/Makefile                         |   1 +
>  drivers/clk/mvebu/ap806-system-controller.c        | 106 +++++++++++++++++++++
>  5 files changed, 145 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/arm/marvell/ap806-system-controller.txt
>  create mode 100644 drivers/clk/mvebu/ap806-system-controller.c
>
> -- 
> 2.6.4
>

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

Re: [PATCH v3 0/3] clk: clock driver for the Marvell Armada AP806

[Thomas Petazzoni]

Michael, Stephen,

On Fri,  4 Mar 2016 13:57:52 +0100, Thomas Petazzoni wrote:
> Michael, Stephen,
> 
> Here is a new version of the clock driver and its DT binding for the
> Marvell Armada AP806. As you will see, there is no longer any
> reference to the DFX Server and changes in the clock tree compared to
> the v2. This is due to the fact that the HW has changed from this
> point of view between the test chips and the final revision, and this
> new version aims at supporting only the final revision.

This third version of the patch series has received the ACK from Rob as
the DT binding maintainer, and from Gregory as the mvebu platform
maintainer.

Do you have any other concern about this series, or can it be applied
soon?

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com