[PATCH 2/4] mvebu: Dove: Instantiate cpufreq driver.

[PATCH 2/4] mvebu: Dove: Instantiate cpufreq driver.

[Andrew Lunn]

Add a platform driver definition to instantiate the dove cpufreq
driver. Also indicate the ARCH has cpufreq support, so allowing the
cpufreq framework to be enabled.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
 arch/arm/Kconfig                       |  1 +
 arch/arm/mach-dove/board-dt.c          |  2 ++
 arch/arm/mach-dove/common.c            | 36 ++++++++++++++++++++++++++++++++++
 arch/arm/mach-dove/common.h            |  1 +
 arch/arm/mach-dove/include/mach/dove.h |  1 +
 5 files changed, 41 insertions(+)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 1ad6fb6..7744415 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -495,6 +495,7 @@ config ARCH_IXP4XX
 
 config ARCH_DOVE
 	bool "Marvell Dove"
+	select ARCH_HAS_CPUFREQ
 	select ARCH_REQUIRE_GPIOLIB
 	select CPU_PJ4
 	select GENERIC_CLOCKEVENTS
diff --git a/arch/arm/mach-dove/board-dt.c b/arch/arm/mach-dove/board-dt.c
index 49f72a8..98202de 100644
--- a/arch/arm/mach-dove/board-dt.c
+++ b/arch/arm/mach-dove/board-dt.c
@@ -70,6 +70,8 @@ static void __init dove_dt_init(void)
 	/* Setup clocks for legacy devices */
 	dove_legacy_clk_init();
 
+	dove_cpufreq_init();
+
 	/* Internal devices not ported to DT yet */
 	dove_pcie_init(1, 1);
 
diff --git a/arch/arm/mach-dove/common.c b/arch/arm/mach-dove/common.c
index c122bcf..9e648a8 100644
--- a/arch/arm/mach-dove/common.c
+++ b/arch/arm/mach-dove/common.c
@@ -344,6 +344,42 @@ void __init dove_sdio1_init(void)
 	platform_device_register(&dove_sdio1);
 }
 
+/*****************************************************************************
+ * CPU Frequency
+ ****************************************************************************/
+static struct resource dove_cpufreq_resources[] = {
+	[0] = {
+		.start  = DOVE_PMU_PHYS_BASE,
+		.end    = DOVE_PMU_PHYS_BASE + 0x7,
+		.flags  = IORESOURCE_MEM,
+		.name   = "cpufreq: DFS"
+	},
+	[1] = {
+		.start  = DOVE_PMU_PHYS_BASE + 0x8000,
+		.end    = DOVE_PMU_PHYS_BASE + 0x8004,
+		.flags  = IORESOURCE_MEM,
+		.name   = "cpufreq PMU CR"
+	},
+	[2] = {
+		.start  = DOVE_PMU_PHYS_BASE + 0x0044,
+		.end    = DOVE_PMU_PHYS_BASE + 0x0048,
+		.flags  = IORESOURCE_MEM,
+		.name   = "cpufreq: PMU Clk Div"
+	},
+};
+
+static struct platform_device dove_cpufreq_device = {
+	.name		= "dove-cpufreq",
+	.id		= -1,
+	.num_resources	= ARRAY_SIZE(dove_cpufreq_resources),
+	.resource	= dove_cpufreq_resources,
+};
+
+void __init dove_cpufreq_init(void)
+{
+	platform_device_register(&dove_cpufreq_device);
+}
+
 void __init dove_setup_cpu_wins(void)
 {
 	/*
diff --git a/arch/arm/mach-dove/common.h b/arch/arm/mach-dove/common.h
index 1d72522..5c9a77b 100644
--- a/arch/arm/mach-dove/common.h
+++ b/arch/arm/mach-dove/common.h
@@ -44,6 +44,7 @@ void dove_spi1_init(void);
 void dove_i2c_init(void);
 void dove_sdio0_init(void);
 void dove_sdio1_init(void);
+void dove_cpufreq_init(void);
 void dove_restart(enum reboot_mode, const char *);
 
 #endif
diff --git a/arch/arm/mach-dove/include/mach/dove.h b/arch/arm/mach-dove/include/mach/dove.h
index 0c4b35f..48db186 100644
--- a/arch/arm/mach-dove/include/mach/dove.h
+++ b/arch/arm/mach-dove/include/mach/dove.h
@@ -144,6 +144,7 @@
 #define  DOVE_SD0_GPIO_SEL		(1 << 0)
 
 /* Power Management */
+#define DOVE_PMU_PHYS_BASE	(DOVE_SB_REGS_PHYS_BASE + 0xd0000)
 #define DOVE_PMU_VIRT_BASE	(DOVE_SB_REGS_VIRT_BASE + 0xd0000)
 #define DOVE_PMU_SIG_CTRL	(DOVE_PMU_VIRT_BASE + 0x802c)
 
-- 
1.8.4.rc3

Re: [PATCH 2/4] mvebu: Dove: Instantiate cpufreq driver.

[Sebastian Hesselbarth]

On 10/19/2013 01:37 PM, Andrew Lunn wrote:
> Add a platform driver definition to instantiate the dove cpufreq
> driver. Also indicate the ARCH has cpufreq support, so allowing the
> cpufreq framework to be enabled.
>
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> ---
>   arch/arm/Kconfig                       |  1 +
>   arch/arm/mach-dove/board-dt.c          |  2 ++
>   arch/arm/mach-dove/common.c            | 36 ++++++++++++++++++++++++++++++++++
>   arch/arm/mach-dove/common.h            |  1 +
>   arch/arm/mach-dove/include/mach/dove.h |  1 +
>   5 files changed, 41 insertions(+)
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 1ad6fb6..7744415 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -495,6 +495,7 @@ config ARCH_IXP4XX
>
>   config ARCH_DOVE
>   	bool "Marvell Dove"
> +	select ARCH_HAS_CPUFREQ
>   	select ARCH_REQUIRE_GPIOLIB
>   	select CPU_PJ4
>   	select GENERIC_CLOCKEVENTS
> diff --git a/arch/arm/mach-dove/board-dt.c b/arch/arm/mach-dove/board-dt.c
> index 49f72a8..98202de 100644
> --- a/arch/arm/mach-dove/board-dt.c
> +++ b/arch/arm/mach-dove/board-dt.c
> @@ -70,6 +70,8 @@ static void __init dove_dt_init(void)
>   	/* Setup clocks for legacy devices */
>   	dove_legacy_clk_init();
>
> +	dove_cpufreq_init();
> +

What ever the outcome of "DT: blessing or curse" discussion at ELCE will
be, are there any plans to probe the cpufreq/cpuidle drivers directly
from DT? Someday, we want to get rid of .machine_init.

>   	/* Internal devices not ported to DT yet */
>   	dove_pcie_init(1, 1);
>
> diff --git a/arch/arm/mach-dove/common.c b/arch/arm/mach-dove/common.c
> index c122bcf..9e648a8 100644
> --- a/arch/arm/mach-dove/common.c
> +++ b/arch/arm/mach-dove/common.c
> @@ -344,6 +344,42 @@ void __init dove_sdio1_init(void)
>   	platform_device_register(&dove_sdio1);
>   }
>
> +/*****************************************************************************
> + * CPU Frequency
> + ****************************************************************************/
> +static struct resource dove_cpufreq_resources[] = {
> +	[0] = {
> +		.start  = DOVE_PMU_PHYS_BASE,
> +		.end    = DOVE_PMU_PHYS_BASE + 0x7,
> +		.flags  = IORESOURCE_MEM,
> +		.name   = "cpufreq: DFS"
> +	},
> +	[1] = {
> +		.start  = DOVE_PMU_PHYS_BASE + 0x8000,
> +		.end    = DOVE_PMU_PHYS_BASE + 0x8004,

BASE + 0x8004 - 1 ?

> +		.flags  = IORESOURCE_MEM,
> +		.name   = "cpufreq PMU CR"
> +	},
> +	[2] = {
> +		.start  = DOVE_PMU_PHYS_BASE + 0x0044,
> +		.end    = DOVE_PMU_PHYS_BASE + 0x0048,

ditto.

Sebastian

> +		.flags  = IORESOURCE_MEM,
> +		.name   = "cpufreq: PMU Clk Div"
> +	},
> +};
> +
> +static struct platform_device dove_cpufreq_device = {
> +	.name		= "dove-cpufreq",
> +	.id		= -1,
> +	.num_resources	= ARRAY_SIZE(dove_cpufreq_resources),
> +	.resource	= dove_cpufreq_resources,
> +};
> +
> +void __init dove_cpufreq_init(void)
> +{
> +	platform_device_register(&dove_cpufreq_device);
> +}
> +
>   void __init dove_setup_cpu_wins(void)
>   {
>   	/*
> diff --git a/arch/arm/mach-dove/common.h b/arch/arm/mach-dove/common.h
> index 1d72522..5c9a77b 100644
> --- a/arch/arm/mach-dove/common.h
> +++ b/arch/arm/mach-dove/common.h
> @@ -44,6 +44,7 @@ void dove_spi1_init(void);
>   void dove_i2c_init(void);
>   void dove_sdio0_init(void);
>   void dove_sdio1_init(void);
> +void dove_cpufreq_init(void);
>   void dove_restart(enum reboot_mode, const char *);
>
>   #endif
> diff --git a/arch/arm/mach-dove/include/mach/dove.h b/arch/arm/mach-dove/include/mach/dove.h
> index 0c4b35f..48db186 100644
> --- a/arch/arm/mach-dove/include/mach/dove.h
> +++ b/arch/arm/mach-dove/include/mach/dove.h
> @@ -144,6 +144,7 @@
>   #define  DOVE_SD0_GPIO_SEL		(1 << 0)
>
>   /* Power Management */
> +#define DOVE_PMU_PHYS_BASE	(DOVE_SB_REGS_PHYS_BASE + 0xd0000)
>   #define DOVE_PMU_VIRT_BASE	(DOVE_SB_REGS_VIRT_BASE + 0xd0000)
>   #define DOVE_PMU_SIG_CTRL	(DOVE_PMU_VIRT_BASE + 0x802c)
>
>

Re: [PATCH 2/4] mvebu: Dove: Instantiate cpufreq driver.

[Andrew Lunn]

On Mon, Oct 21, 2013 at 11:47:32AM +0100, Sebastian Hesselbarth wrote:
> On 10/19/2013 01:37 PM, Andrew Lunn wrote:
> >Add a platform driver definition to instantiate the dove cpufreq
> >driver. Also indicate the ARCH has cpufreq support, so allowing the
> >cpufreq framework to be enabled.
> >
> >Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> >---
> >  arch/arm/Kconfig                       |  1 +
> >  arch/arm/mach-dove/board-dt.c          |  2 ++
> >  arch/arm/mach-dove/common.c            | 36 ++++++++++++++++++++++++++++++++++
> >  arch/arm/mach-dove/common.h            |  1 +
> >  arch/arm/mach-dove/include/mach/dove.h |  1 +
> >  5 files changed, 41 insertions(+)
> >
> >diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> >index 1ad6fb6..7744415 100644
> >--- a/arch/arm/Kconfig
> >+++ b/arch/arm/Kconfig
> >@@ -495,6 +495,7 @@ config ARCH_IXP4XX
> >
> >  config ARCH_DOVE
> >  	bool "Marvell Dove"
> >+	select ARCH_HAS_CPUFREQ
> >  	select ARCH_REQUIRE_GPIOLIB
> >  	select CPU_PJ4
> >  	select GENERIC_CLOCKEVENTS
> >diff --git a/arch/arm/mach-dove/board-dt.c b/arch/arm/mach-dove/board-dt.c
> >index 49f72a8..98202de 100644
> >--- a/arch/arm/mach-dove/board-dt.c
> >+++ b/arch/arm/mach-dove/board-dt.c
> >@@ -70,6 +70,8 @@ static void __init dove_dt_init(void)
> >  	/* Setup clocks for legacy devices */
> >  	dove_legacy_clk_init();
> >
> >+	dove_cpufreq_init();
> >+
> 
> What ever the outcome of "DT: blessing or curse" discussion at ELCE will
> be, are there any plans to probe the cpufreq/cpuidle drivers directly
> from DT? Someday, we want to get rid of .machine_init.

Hi Sebastian

This has already been discussed once for cpufreq drivers. I triggered
it with the kirkwood cpufreq driver. The outcome was that not
everything needs to the DT, platform drivers are still OK for things
which are not really devices. But as you say, the outcome from
Edinburgh might repeal that decision.

> >+	[1] = {
> >+		.start  = DOVE_PMU_PHYS_BASE + 0x8000,
> >+		.end    = DOVE_PMU_PHYS_BASE + 0x8004,
> 
> BASE + 0x8004 - 1 ?

Ah, yes, was thinking DT.

See you soon,

    Andrew

[PATCH 1/4] cpufreq: Add a cpufreq driver for Marvell Dove

[Andrew Lunn]

The Marvell Dove SoC can run the CPU at two frequencies. The high
frequencey is from a PLL, while the lower is the same as the DDR
clock. Add a cpufreq driver to swap between these frequences.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
---
Sort header files
Remove unneeded header files
Notify only on change
Use get_cpu_device(0), devm_clk_get()
Use platform_get_resource_byname()
Error check clk_prepare_enable()
Comment the interrupt handler
---
 drivers/cpufreq/Kconfig.arm    |   5 +
 drivers/cpufreq/Makefile       |   1 +
 drivers/cpufreq/dove-cpufreq.c | 279 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 285 insertions(+)
 create mode 100644 drivers/cpufreq/dove-cpufreq.c

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 701ec95..9560384 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -8,6 +8,11 @@ config ARM_BIG_LITTLE_CPUFREQ
 	help
 	  This enables the Generic CPUfreq driver for ARM big.LITTLE platforms.
 
+config ARM_DOVE_CPUFREQ
+	def_bool ARCH_DOVE && OF
+	help
+	  This adds the CPUFreq driver for Marvell Dove SoCs.
+
 config ARM_DT_BL_CPUFREQ
 	tristate "Generic probing via DT for ARM big LITTLE CPUfreq driver"
 	depends on ARM_BIG_LITTLE_CPUFREQ && OF
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index b7948bb..5956661 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_ARM_DT_BL_CPUFREQ)		+= arm_big_little_dt.o
 
 obj-$(CONFIG_ARCH_DAVINCI_DA850)	+= davinci-cpufreq.o
 obj-$(CONFIG_UX500_SOC_DB8500)		+= dbx500-cpufreq.o
+obj-$(CONFIG_ARM_DOVE_CPUFREQ)		+= dove-cpufreq.o
 obj-$(CONFIG_ARM_EXYNOS_CPUFREQ)	+= exynos-cpufreq.o
 obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ)	+= exynos4210-cpufreq.o
 obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ)	+= exynos4x12-cpufreq.o
diff --git a/drivers/cpufreq/dove-cpufreq.c b/drivers/cpufreq/dove-cpufreq.c
new file mode 100644
index 0000000..10f013c
--- /dev/null
+++ b/drivers/cpufreq/dove-cpufreq.c
@@ -0,0 +1,279 @@
+/*
+ *	dove_freq.c: cpufreq driver for the Marvell dove
+ *
+ *	Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <asm/proc-fns.h>
+
+#define DFS_CR			0x00
+#define  DFS_EN			BIT(0)
+#define  CPU_SLOW_EN		BIT(1)
+#define  L2_RATIO_OFFS		9
+#define  L2_RATIO_MASK		(0x3F << L2_RATIO_OFFS)
+#define DFS_SR			0x04
+#define  CPU_SLOW_MODE_STTS	BIT(1)
+
+/* PMU_CR */
+#define  MASK_FIQ		BIT(28)
+#define  MASK_IRQ		BIT(24)	/* PMU_CR */
+
+/* CPU Clock Divider Control 0 Register */
+#define DPRATIO_OFFS		24
+#define DPRATIO_MASK		(0x3F << DPRATIO_OFFS)
+#define XPRATIO_OFFS		16
+#define XPRATIO_MASK		(0x3F << XPRATIO_OFFS)
+
+static struct priv
+{
+	struct clk *cpu_clk;
+	struct clk *ddr_clk;
+	struct device *dev;
+	unsigned long dpratio;
+	unsigned long xpratio;
+	void __iomem *dfs;
+	void __iomem *pmu_cr;
+	void __iomem *pmu_clk_div;
+} priv;
+
+#define STATE_CPU_FREQ 0x01
+#define STATE_DDR_FREQ 0x02
+
+/*
+ * Dove can swap the clock to the CPU between two clocks:
+ *
+ * - cpu clk
+ * - ddr clk
+ *
+ * The frequencies are set at runtime before registering this
+ * table.
+ */
+static struct cpufreq_frequency_table dove_freq_table[] = {
+	{STATE_CPU_FREQ,	0}, /* CPU uses cpuclk */
+	{STATE_DDR_FREQ,	0}, /* CPU uses ddrclk */
+	{0,			CPUFREQ_TABLE_END},
+};
+
+static unsigned int dove_cpufreq_get_cpu_frequency(unsigned int cpu)
+{
+	unsigned long reg = readl_relaxed(priv.dfs + DFS_SR);
+
+	if (reg & CPU_SLOW_MODE_STTS)
+		return dove_freq_table[1].frequency;
+	return dove_freq_table[0].frequency;
+}
+
+static void dove_cpufreq_set_cpu_state(struct cpufreq_policy *policy,
+				       unsigned int index)
+{
+	struct cpufreq_freqs freqs;
+	unsigned int state = dove_freq_table[index].driver_data;
+	unsigned long reg, cr;
+
+	freqs.old = dove_cpufreq_get_cpu_frequency(0);
+	freqs.new = dove_freq_table[index].frequency;
+
+	if (freqs.old != freqs.new) {
+		cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+		local_irq_disable();
+
+		/* Mask IRQ and FIQ to CPU */
+		cr = readl(priv.pmu_cr);
+		cr |= MASK_IRQ | MASK_FIQ;
+		writel(cr, priv.pmu_cr);
+
+		/* Set/Clear the CPU_SLOW_EN bit */
+		reg = readl_relaxed(priv.dfs + DFS_CR);
+		reg &= ~L2_RATIO_MASK;
+
+		switch (state) {
+		case STATE_CPU_FREQ:
+			reg |= priv.xpratio;
+			reg &= ~CPU_SLOW_EN;
+			break;
+		case STATE_DDR_FREQ:
+			reg |= (priv.dpratio | CPU_SLOW_EN);
+			break;
+		}
+
+		/* Start the DFS process */
+		reg |= DFS_EN;
+
+		writel(reg, priv.dfs + DFS_CR);
+
+		/* Wait-for-Interrupt, while the hardware changes frequency */
+		cpu_do_idle();
+
+		local_irq_enable();
+		cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	}
+}
+
+static int dove_cpufreq_target(struct cpufreq_policy *policy,
+			    unsigned int target_freq,
+			    unsigned int relation)
+{
+	unsigned int index = 0;
+
+	if (cpufreq_frequency_table_target(policy, dove_freq_table,
+				target_freq, relation, &index))
+		return -EINVAL;
+
+	dove_cpufreq_set_cpu_state(policy, index);
+
+	return 0;
+}
+
+static int dove_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	return cpufreq_generic_init(policy, dove_freq_table, 5000);
+}
+
+/*
+ * Handle the interrupt raised when the frequency change is
+ * complete.
+ */
+static irqreturn_t dove_cpufreq_irq(int irq, void *dev)
+{
+	return IRQ_HANDLED;
+}
+
+static struct cpufreq_driver dove_cpufreq_driver = {
+	.get	= dove_cpufreq_get_cpu_frequency,
+	.verify	= cpufreq_generic_frequency_table_verify,
+	.target = dove_cpufreq_target,
+	.init	= dove_cpufreq_cpu_init,
+	.exit	= cpufreq_generic_exit,
+	.name	= "dove-cpufreq",
+	.attr	= cpufreq_generic_attr,
+};
+
+static int dove_cpufreq_probe(struct platform_device *pdev)
+{
+	struct device *cpu_dev;
+	struct resource *res;
+	int err, irq;
+
+	memset(&priv, 0, sizeof(priv));
+	priv.dev = &pdev->dev;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+					   "cpufreq: DFS");
+	priv.dfs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv.dfs))
+		return PTR_ERR(priv.dfs);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+					   "cpufreq: PMU CR");
+	priv.pmu_cr = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv.pmu_cr))
+		return PTR_ERR(priv.pmu_cr);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+					   "cpufreq: PMU Clk Div");
+	priv.pmu_clk_div = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv.pmu_clk_div))
+		return PTR_ERR(priv.pmu_clk_div);
+
+	cpu_dev = get_cpu_device(0);
+
+	priv.cpu_clk = devm_clk_get(cpu_dev, "cpu_clk");
+	if (IS_ERR(priv.cpu_clk)) {
+		err = PTR_ERR(priv.cpu_clk);
+		goto out;
+	}
+
+	err = clk_prepare_enable(priv.cpu_clk);
+	if (err)
+		goto out;
+
+	dove_freq_table[0].frequency = clk_get_rate(priv.cpu_clk) / 1000;
+
+	priv.ddr_clk = devm_clk_get(cpu_dev, "ddrclk");
+	if (IS_ERR(priv.ddr_clk)) {
+		err = PTR_ERR(priv.ddr_clk);
+		goto out;
+	}
+
+	err = clk_prepare_enable(priv.ddr_clk);
+	if (err)
+		goto out;
+
+	dove_freq_table[1].frequency = clk_get_rate(priv.ddr_clk) / 1000;
+
+	irq = irq_of_parse_and_map(cpu_dev->of_node, 0);
+	if (!irq) {
+		err = -ENXIO;
+		goto out;
+	}
+
+	err = devm_request_irq(&pdev->dev, irq, dove_cpufreq_irq,
+			       0, "dove-cpufreq", NULL);
+	if (err) {
+		dev_err(&pdev->dev, "cannot assign irq %d, %d\n", irq, err);
+		goto out;
+	}
+
+	/* Read the target ratio which should be the DDR ratio */
+	priv.dpratio = readl_relaxed(priv.pmu_clk_div);
+	priv.dpratio = (priv.dpratio & DPRATIO_MASK) >> DPRATIO_OFFS;
+	priv.dpratio = priv.dpratio << L2_RATIO_OFFS;
+
+	/* Save L2 ratio at reset */
+	priv.xpratio = readl(priv.pmu_clk_div);
+	priv.xpratio = (priv.xpratio & XPRATIO_MASK) >> XPRATIO_OFFS;
+	priv.xpratio = priv.xpratio << L2_RATIO_OFFS;
+
+	err = cpufreq_register_driver(&dove_cpufreq_driver);
+	if (!err)
+		return 0;
+
+	dev_err(priv.dev, "Failed to register cpufreq driver");
+
+out:
+	clk_disable_unprepare(priv.ddr_clk);
+	clk_disable_unprepare(priv.cpu_clk);
+
+	return err;
+}
+
+static int dove_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_driver(&dove_cpufreq_driver);
+
+	clk_disable_unprepare(priv.ddr_clk);
+	clk_disable_unprepare(priv.cpu_clk);
+
+	return 0;
+}
+
+static struct platform_driver dove_cpufreq_platform_driver = {
+	.probe = dove_cpufreq_probe,
+	.remove = dove_cpufreq_remove,
+	.driver = {
+		.name = "dove-cpufreq",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_platform_driver(dove_cpufreq_platform_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch");
+MODULE_DESCRIPTION("cpufreq driver for Marvell's dove CPU");
+MODULE_ALIAS("platform:dove-cpufreq");
-- 
1.8.4.rc3

[PATCH 2/4] mvebu: Dove: Instantiate cpufreq driver.

[Andrew Lunn]

Add a platform driver definition to instantiate the dove cpufreq
driver. Also indicate the ARCH has cpufreq support, so allowing the
cpufreq framework to be enabled.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
---
Make resource names consistent.
Fix length of ranges
---
 arch/arm/Kconfig                       |  1 +
 arch/arm/mach-dove/board-dt.c          |  2 ++
 arch/arm/mach-dove/common.c            | 36 ++++++++++++++++++++++++++++++++++
 arch/arm/mach-dove/common.h            |  1 +
 arch/arm/mach-dove/include/mach/dove.h |  1 +
 5 files changed, 41 insertions(+)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 1ad6fb6..7744415 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -495,6 +495,7 @@ config ARCH_IXP4XX
 
 config ARCH_DOVE
 	bool "Marvell Dove"
+	select ARCH_HAS_CPUFREQ
 	select ARCH_REQUIRE_GPIOLIB
 	select CPU_PJ4
 	select GENERIC_CLOCKEVENTS
diff --git a/arch/arm/mach-dove/board-dt.c b/arch/arm/mach-dove/board-dt.c
index 49f72a8..98202de 100644
--- a/arch/arm/mach-dove/board-dt.c
+++ b/arch/arm/mach-dove/board-dt.c
@@ -70,6 +70,8 @@ static void __init dove_dt_init(void)
 	/* Setup clocks for legacy devices */
 	dove_legacy_clk_init();
 
+	dove_cpufreq_init();
+
 	/* Internal devices not ported to DT yet */
 	dove_pcie_init(1, 1);
 
diff --git a/arch/arm/mach-dove/common.c b/arch/arm/mach-dove/common.c
index c122bcf..323fcd4 100644
--- a/arch/arm/mach-dove/common.c
+++ b/arch/arm/mach-dove/common.c
@@ -344,6 +344,42 @@ void __init dove_sdio1_init(void)
 	platform_device_register(&dove_sdio1);
 }
 
+/*****************************************************************************
+ * CPU Frequency
+ ****************************************************************************/
+static struct resource dove_cpufreq_resources[] = {
+	[0] = {
+		.start  = DOVE_PMU_PHYS_BASE,
+		.end    = DOVE_PMU_PHYS_BASE + 0x7,
+		.flags  = IORESOURCE_MEM,
+		.name   = "cpufreq: DFS"
+	},
+	[1] = {
+		.start  = DOVE_PMU_PHYS_BASE + 0x8000,
+		.end    = DOVE_PMU_PHYS_BASE + 0x8003,
+		.flags  = IORESOURCE_MEM,
+		.name   = "cpufreq: PMU CR"
+	},
+	[2] = {
+		.start  = DOVE_PMU_PHYS_BASE + 0x0044,
+		.end    = DOVE_PMU_PHYS_BASE + 0x0047,
+		.flags  = IORESOURCE_MEM,
+		.name   = "cpufreq: PMU Clk Div"
+	},
+};
+
+static struct platform_device dove_cpufreq_device = {
+	.name		= "dove-cpufreq",
+	.id		= -1,
+	.num_resources	= ARRAY_SIZE(dove_cpufreq_resources),
+	.resource	= dove_cpufreq_resources,
+};
+
+void __init dove_cpufreq_init(void)
+{
+	platform_device_register(&dove_cpufreq_device);
+}
+
 void __init dove_setup_cpu_wins(void)
 {
 	/*
diff --git a/arch/arm/mach-dove/common.h b/arch/arm/mach-dove/common.h
index 1d72522..5c9a77b 100644
--- a/arch/arm/mach-dove/common.h
+++ b/arch/arm/mach-dove/common.h
@@ -44,6 +44,7 @@ void dove_spi1_init(void);
 void dove_i2c_init(void);
 void dove_sdio0_init(void);
 void dove_sdio1_init(void);
+void dove_cpufreq_init(void);
 void dove_restart(enum reboot_mode, const char *);
 
 #endif
diff --git a/arch/arm/mach-dove/include/mach/dove.h b/arch/arm/mach-dove/include/mach/dove.h
index 0c4b35f..48db186 100644
--- a/arch/arm/mach-dove/include/mach/dove.h
+++ b/arch/arm/mach-dove/include/mach/dove.h
@@ -144,6 +144,7 @@
 #define  DOVE_SD0_GPIO_SEL		(1 << 0)
 
 /* Power Management */
+#define DOVE_PMU_PHYS_BASE	(DOVE_SB_REGS_PHYS_BASE + 0xd0000)
 #define DOVE_PMU_VIRT_BASE	(DOVE_SB_REGS_VIRT_BASE + 0xd0000)
 #define DOVE_PMU_SIG_CTRL	(DOVE_PMU_VIRT_BASE + 0x802c)
 
-- 
1.8.4.rc3

[PATCH 3/4] mvebu: Dove: Enable cpufreq driver in defconfig

[Andrew Lunn]

Add cpufreq to dove_defconfig, so it is built by default.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
---
 arch/arm/configs/dove_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/configs/dove_defconfig b/arch/arm/configs/dove_defconfig
index 1101054..3d92350 100644
--- a/arch/arm/configs/dove_defconfig
+++ b/arch/arm/configs/dove_defconfig
@@ -22,6 +22,8 @@ CONFIG_ZBOOT_ROM_TEXT=0x0
 CONFIG_ZBOOT_ROM_BSS=0x0
 CONFIG_ARM_APPENDED_DTB=y
 CONFIG_ARM_ATAG_DTB_COMPAT=y
+CONFIG_CPU_FREQ=y
+CONFIG_CPU_FREQ_GOV_ONDEMAND=y
 CONFIG_VFP=y
 CONFIG_NET=y
 CONFIG_PACKET=y
-- 
1.8.4.rc3

[PATCH 4/4] mvebu: Dove: Add clocks and DFS interrupt to cpu node in DT.

[Andrew Lunn]

The dove-cpufreq driver needs access to the DDR and CPU clock.  There
is also an interrupt generated when the DFS hardware completes a
change of frequencey. Add these to the cpu node in DT.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
---
 arch/arm/boot/dts/dove.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/boot/dts/dove.dtsi b/arch/arm/boot/dts/dove.dtsi
index 1fd615d..e96d7a6 100644
--- a/arch/arm/boot/dts/dove.dtsi
+++ b/arch/arm/boot/dts/dove.dtsi
@@ -19,6 +19,10 @@
 			device_type = "cpu";
 			next-level-cache = <&l2>;
 			reg = <0>;
+			clocks = <&core_clk 1>, <&core_clk 3>;
+			clock-names = "cpu_clk", "ddrclk";
+			interrupt-parent = <&pmu_intc>;
+			interrupts = <0>;
 		};
 	};
 
-- 
1.8.4.rc3

Re: [PATCH 1/4] cpufreq: Add a cpufreq driver for Marvell Dove

[Viresh Kumar]

On 23 October 2013 18:34, Andrew Lunn <andrew@lunn.ch> wrote:
> The Marvell Dove SoC can run the CPU at two frequencies. The high
> frequencey is from a PLL, while the lower is the same as the DDR
> clock. Add a cpufreq driver to swap between these frequences.
>
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
> ---
> Sort header files
> Comment the interrupt handler

Really? I don't see these two comments being incorporated..
Also, you would be required to update your patchset ones my
patches are in (And that will happen for v3.13)..

Re: [PATCH 1/4] cpufreq: Add a cpufreq driver for Marvell Dove

[Andrew Lunn]

On Wed, Oct 23, 2013 at 07:10:41PM +0530, Viresh Kumar wrote:
> On 23 October 2013 18:34, Andrew Lunn <andrew@lunn.ch> wrote:
> > The Marvell Dove SoC can run the CPU at two frequencies. The high
> > frequencey is from a PLL, while the lower is the same as the DDR
> > clock. Add a cpufreq driver to swap between these frequences.
> >
> > Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> > Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
> > ---
> > Sort header files
> > Comment the interrupt handler
> 
> Really? I don't see these two comments being incorporated..
> Also, you would be required to update your patchset ones my
> patches are in (And that will happen for v3.13)..

+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <asm/proc-fns.h>

There does seem to be a convention that kernel.h and module.h come
first, and then i have the rest in order. 

+/*
+ * Handle the interrupt raised when the frequency change is
+ * complete.
+ */
+static irqreturn_t dove_cpufreq_irq(int irq, void *dev)
+{
+       return IRQ_HANDLED;
+}

What more would you like to see in the comment?

Thanks
     Andrew

Re: [PATCH 1/4] cpufreq: Add a cpufreq driver for Marvell Dove

[Viresh Kumar]

On 23 October 2013 19:21, Andrew Lunn <andrew@lunn.ch> wrote:
> There does seem to be a convention that kernel.h and module.h come
> first, and then i have the rest in order.

Atleast I am not aware of any such convention and so got
confused.

> +/*
> + * Handle the interrupt raised when the frequency change is
> + * complete.
> + */
> +static irqreturn_t dove_cpufreq_irq(int irq, void *dev)
> +{
> +       return IRQ_HANDLED;
> +}
>
> What more would you like to see in the comment?

Ahh.. I read it as "Commented interrupt handler and so it is no
more registered" :)

So, you have actually tested your code without interrupt handler?
What exactly happens in that case?

Re: [PATCH 1/4] cpufreq: Add a cpufreq driver for Marvell Dove

[Andrew Lunn]

> So, you have actually tested your code without interrupt handler?

No.

> What exactly happens in that case?

Take a look at request_threaded_irq(). It contains:

1421         if (!handler) {
1422                 if (!thread_fn)
1423                         return -EINVAL;

So devm_request_irq() will fail, and so the probe function will fail.

   Andrew

Re: [PATCH 1/4] cpufreq: Add a cpufreq driver for Marvell Dove

[Andrew Lunn]

On Wed, Oct 23, 2013 at 08:30:02PM +0530, Viresh Kumar wrote:
> On 23 October 2013 20:06, Andrew Lunn <andrew@lunn.ch> wrote:
> >> So, you have actually tested your code without interrupt handler?
> >
> > No.
> 
> It would be better if you atleast try this and confirm that this dummy
> handler is required.
> 
> >> What exactly happens in that case?
> >
> > Take a look at request_threaded_irq(). It contains:
> >
> > 1421         if (!handler) {
> > 1422                 if (!thread_fn)
> > 1423                         return -EINVAL;
> >
> > So devm_request_irq() will fail, and so the probe function will fail.
> 
> Obviously I wanted you to remove all irq specific code and hence
> devm_request_irq() :)

So you want to know if WFI exits without an interrupt being delivered?
The Marvell documentation says the interrupt should be enabled, but we
can try it with it disabled.

    Andrew

Re: [PATCH 1/4] cpufreq: Add a cpufreq driver for Marvell Dove

[Viresh Kumar]

On 23 October 2013 20:06, Andrew Lunn <andrew@lunn.ch> wrote:
>> So, you have actually tested your code without interrupt handler?
>
> No.

It would be better if you atleast try this and confirm that this dummy
handler is required.

>> What exactly happens in that case?
>
> Take a look at request_threaded_irq(). It contains:
>
> 1421         if (!handler) {
> 1422                 if (!thread_fn)
> 1423                         return -EINVAL;
>
> So devm_request_irq() will fail, and so the probe function will fail.

Obviously I wanted you to remove all irq specific code and hence
devm_request_irq() :)

Re: [PATCH 1/4] cpufreq: Add a cpufreq driver for Marvell Dove

[Viresh Kumar]

On 23 October 2013 20:29, Andrew Lunn <andrew@lunn.ch> wrote:
> So you want to know if WFI exits without an interrupt being delivered?

Yeah..

> The Marvell documentation says the interrupt should be enabled, but we
> can try it with it disabled.

Yes, that will work.. So we will not explicitly disable interrupt but let kernel
do it for us (i.e. by not registering an interrupt handler)..

Re: [PATCH 1/4] cpufreq: Add a cpufreq driver for Marvell Dove

[Andrew Lunn]

On Wed, Oct 23, 2013 at 08:30:02PM +0530, Viresh Kumar wrote:
> On 23 October 2013 20:06, Andrew Lunn <andrew@lunn.ch> wrote:
> >> So, you have actually tested your code without interrupt handler?
> >
> > No.
> 
> It would be better if you atleast try this and confirm that this dummy
> handler is required.

Hi Viresh

I have tested this now. The dummy handler is required. Without it, it
seems like the WFI exits at the next timer tick, not immediately once
the cpufreq change has finished. I get poor numbers out of
cpufreq-bench without the handler.

	      Andrew

Re: [PATCH 1/4] cpufreq: Add a cpufreq driver for Marvell Dove

[Viresh Kumar]

On 28 October 2013 17:01, Andrew Lunn <andrew@lunn.ch> wrote:
> I have tested this now. The dummy handler is required. Without it, it
> seems like the WFI exits at the next timer tick, not immediately once
> the cpufreq change has finished. I get poor numbers out of
> cpufreq-bench without the handler.

Ahh.. that helps.. You can now put exactly this stuff in the comment over
the handler..