* [PATCH 0/3] Kirkwoode cpufreq driver
@ 2013-01-18 14:20 Andrew Lunn
2013-01-18 14:20 ` [PATCH 1/3] cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs Andrew Lunn
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: Andrew Lunn @ 2013-01-18 14:20 UTC (permalink / raw)
To: linux-arm-kernel
This patchset adds a cpufreq driver for Marvell Kirkwood SoCs.
The changes to kirkwood_defconfig enable it and set the default
governor to ondemand.
Andrew Lunn (3):
cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs
arm: kirkwood: Instantiate cpufreq driver
arm: kirkwood: Enable cpufreq and ondemand on kirkwood_defconfig
arch/arm/Kconfig | 1 +
arch/arm/configs/kirkwood_defconfig | 3 +
arch/arm/mach-kirkwood/board-dt.c | 3 +-
arch/arm/mach-kirkwood/common.c | 23 ++
arch/arm/mach-kirkwood/common.h | 2 +
arch/arm/mach-kirkwood/include/mach/bridge-regs.h | 2 +
drivers/clk/mvebu/clk-gating-ctrl.c | 1 +
drivers/cpufreq/Kconfig.arm | 6 +
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/kirkwood-cpufreq.c | 273 +++++++++++++++++++++
10 files changed, 314 insertions(+), 1 deletion(-)
create mode 100644 drivers/cpufreq/kirkwood-cpufreq.c
--
1.7.10.4
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 1/3] cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs
2013-01-18 14:20 [PATCH 0/3] Kirkwoode cpufreq driver Andrew Lunn
@ 2013-01-18 14:20 ` Andrew Lunn
2013-01-18 14:39 ` Peter Korsgaard
2013-01-20 4:11 ` Viresh Kumar
2013-01-18 14:20 ` [PATCH 2/3] arm: kirkwood: Instantiate cpufreq driver Andrew Lunn
2013-01-18 14:20 ` [PATCH 3/3] arm: kirkwood: Enable cpufreq and ondemand on kirkwood_defconfig Andrew Lunn
2 siblings, 2 replies; 7+ messages in thread
From: Andrew Lunn @ 2013-01-18 14:20 UTC (permalink / raw)
To: linux-arm-kernel
The Marvell Kirkwood SoCs have simple cpufreq support in hardware. The
CPU can either use the a high speed cpu clock, or the slower DDR
clock. Add a driver to swap between these two clock sources.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
drivers/clk/mvebu/clk-gating-ctrl.c | 1 +
drivers/cpufreq/Kconfig.arm | 6 +
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/kirkwood-cpufreq.c | 273 +++++++++++++++++++++++++++++++++++
4 files changed, 281 insertions(+)
create mode 100644 drivers/cpufreq/kirkwood-cpufreq.c
diff --git a/drivers/clk/mvebu/clk-gating-ctrl.c b/drivers/clk/mvebu/clk-gating-ctrl.c
index 8fa5408..ebf141d 100644
--- a/drivers/clk/mvebu/clk-gating-ctrl.c
+++ b/drivers/clk/mvebu/clk-gating-ctrl.c
@@ -193,6 +193,7 @@ static const struct mvebu_soc_descr __initconst kirkwood_gating_descr[] = {
{ "runit", NULL, 7 },
{ "xor0", NULL, 8 },
{ "audio", NULL, 9 },
+ { "powersave", "cpuclk", 11 },
{ "sata0", NULL, 14 },
{ "sata1", NULL, 15 },
{ "xor1", NULL, 16 },
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index a0b3661..08ca366 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -77,6 +77,12 @@ config ARM_EXYNOS5250_CPUFREQ
This adds the CPUFreq driver for Samsung EXYNOS5250
SoC.
+config ARM_KIRKWOOD_CPUFREQ
+ def_bool ARCH_KIRKWOOD && OF
+ help
+ This adds the CPUFreq driver for Marvell Kirkwood
+ SoCs.
+
config ARM_SPEAR_CPUFREQ
bool "SPEAr CPUFreq support"
depends on PLAT_SPEAR
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index fadc4d4..39a0ffe 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_ARM_EXYNOS_CPUFREQ) += exynos-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) += exynos4210-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ) += exynos4x12-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ) += exynos5250-cpufreq.o
+obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ) += kirkwood-cpufreq.o
obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o
obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o
diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
new file mode 100644
index 0000000..4f0a435
--- /dev/null
+++ b/drivers/cpufreq/kirkwood-cpufreq.c
@@ -0,0 +1,273 @@
+/*
+ * kirkwood_freq.c: cpufreq driver for the Marvell kirkwood
+ *
+ * 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/init.h>
+#include <linux/platform_device.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/timex.h>
+#include <linux/io.h>
+#include <asm/proc-fns.h>
+
+#define CPU_SW_INT_BLK BIT(28)
+
+
+#include <linux/clk-private.h>
+
+static struct priv
+{
+ struct clk *cpu_clk;
+ struct clk *ddr_clk;
+ struct clk *powersave_clk;
+ struct device *dev;
+ void __iomem *base;
+} priv;
+
+#define STATE_CPU_FREQ 0x01
+#define STATE_DDR_FREQ 0x02
+
+/* Kirkwood 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 kirkwood_freq_table[] = {
+ {STATE_CPU_FREQ, 0}, /* CPU uses cpuclk */
+ {STATE_DDR_FREQ, 0}, /* CPU uses ddrclk */
+ {0, CPUFREQ_TABLE_END},
+};
+
+static unsigned int kirkwood_cpufreq_get_cpu_frequency(unsigned int cpu)
+{
+ if (__clk_is_enabled(priv.powersave_clk))
+ return kirkwood_freq_table[1].frequency;
+ return kirkwood_freq_table[0].frequency;
+}
+
+static void kirkwood_cpufreq_set_cpu_state(unsigned int index)
+{
+
+ struct cpufreq_freqs freqs;
+ unsigned int state = kirkwood_freq_table[index].index;
+ unsigned long reg;
+
+ freqs.old = kirkwood_cpufreq_get_cpu_frequency(0);
+ freqs.new = kirkwood_freq_table[index].frequency;
+ freqs.cpu = 0; /* Kirkwood is UP */
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+ dev_dbg(priv.dev, "Attempting to set frequency to %i KHz\n",
+ kirkwood_freq_table[index].frequency);
+ dev_dbg(priv.dev, "old frequency was %i KHz\n",
+ kirkwood_cpufreq_get_cpu_frequency(0));
+
+ if (freqs.old != freqs.new) {
+ local_irq_disable();
+
+ /* Disable interrupts to the CPU */
+ reg = readl_relaxed(priv.base);
+ reg |= CPU_SW_INT_BLK;
+ writel(reg, priv.base);
+
+ switch (state) {
+ case STATE_CPU_FREQ:
+ clk_disable(priv.powersave_clk);
+ break;
+ case STATE_DDR_FREQ:
+ clk_enable(priv.powersave_clk);
+ break;
+ default:
+ dev_err(priv.dev, "Unexpected cpufreq state");
+ }
+
+ /* Wait-for-Interrupt, which the hardware changes frequency */
+ cpu_do_idle();
+
+ /* Enable interrupts to the CPU */
+ reg = readl_relaxed(priv.base);
+ reg &= ~CPU_SW_INT_BLK;
+ writel(reg, priv.base);
+
+ local_irq_enable();
+ }
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+};
+
+static int kirkwood_cpufreq_verify(struct cpufreq_policy *policy)
+{
+ return cpufreq_frequency_table_verify(policy, &kirkwood_freq_table[0]);
+}
+
+static int kirkwood_cpufreq_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ unsigned int index = 0;
+
+ if (cpufreq_frequency_table_target(policy, kirkwood_freq_table,
+ target_freq, relation, &index))
+ return -EINVAL;
+
+ kirkwood_cpufreq_set_cpu_state(index);
+
+ return 0;
+}
+
+/*
+ * Module init and exit code
+ */
+static int kirkwood_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+ int result;
+
+ /* cpuinfo and default policy values */
+ policy->cpuinfo.transition_latency = 5000; /* 5uS */
+ policy->cur = kirkwood_cpufreq_get_cpu_frequency(0);
+
+ result = cpufreq_frequency_table_cpuinfo(policy, kirkwood_freq_table);
+ if (result)
+ return result;
+
+ cpufreq_frequency_table_get_attr(kirkwood_freq_table, policy->cpu);
+
+ return 0;
+}
+
+static int kirkwood_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+ cpufreq_frequency_table_put_attr(policy->cpu);
+ return 0;
+}
+
+static struct freq_attr *kirkwood_cpufreq_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
+
+static struct cpufreq_driver kirkwood_cpufreq_driver = {
+ .get = kirkwood_cpufreq_get_cpu_frequency,
+ .verify = kirkwood_cpufreq_verify,
+ .target = kirkwood_cpufreq_target,
+ .init = kirkwood_cpufreq_cpu_init,
+ .exit = kirkwood_cpufreq_cpu_exit,
+ .name = "kirkwood_freq",
+ .owner = THIS_MODULE,
+ .attr = kirkwood_cpufreq_attr,
+};
+
+static int kirkwood_cpufreq_probe(struct platform_device *pdev)
+{
+ struct device_node *np = of_find_compatible_node(
+ NULL, NULL, "marvell,kirkwood-core-clock");
+
+ struct of_phandle_args clkspec;
+ struct resource *res;
+ int err;
+
+ priv.dev = &pdev->dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "Cannot get memory resource\n");
+ return -ENODEV;
+ }
+ priv.base = devm_request_and_ioremap(&pdev->dev, res);
+ if (!priv.base) {
+ dev_err(&pdev->dev, "Cannot ioremap\n");
+ return -ENOMEM;
+ }
+
+ clkspec.np = np;
+ clkspec.args_count = 1;
+ clkspec.args[0] = 1;
+
+ priv.cpu_clk = of_clk_get_from_provider(&clkspec);
+ if (IS_ERR(priv.cpu_clk)) {
+ dev_err(priv.dev, "Unable to get cpuclk");
+ return PTR_ERR(priv.cpu_clk);
+ }
+
+ clk_prepare_enable(priv.cpu_clk);
+ kirkwood_freq_table[0].frequency = clk_get_rate(priv.cpu_clk) / 1000;
+
+ clkspec.args[0] = 3;
+ priv.ddr_clk = of_clk_get_from_provider(&clkspec);
+ if (IS_ERR(priv.ddr_clk)) {
+ dev_err(priv.dev, "Unable to get ddrclk");
+ err = PTR_ERR(priv.ddr_clk);
+ goto out_cpu;
+ }
+
+ clk_prepare_enable(priv.ddr_clk);
+ kirkwood_freq_table[1].frequency = clk_get_rate(priv.ddr_clk) / 1000;
+
+ np = of_find_compatible_node(NULL, NULL,
+ "marvell,kirkwood-gating-clock");
+ clkspec.np = np;
+ clkspec.args[0] = 11;
+ priv.powersave_clk = of_clk_get_from_provider(&clkspec);
+ if (IS_ERR(priv.powersave_clk)) {
+ dev_err(priv.dev, "Unable to get powersave");
+ err = PTR_ERR(priv.powersave_clk);
+ goto out_ddr;
+ }
+ clk_prepare(priv.powersave_clk);
+
+ err = cpufreq_register_driver(&kirkwood_cpufreq_driver);
+ if (!err)
+ return 0;
+ dev_err(priv.dev, "Failed to register cpufreq driver");
+
+ clk_disable_unprepare(priv.powersave_clk);
+out_ddr:
+ clk_disable_unprepare(priv.ddr_clk);
+out_cpu:
+ clk_disable_unprepare(priv.cpu_clk);
+
+ return err;
+}
+
+
+static int kirkwood_cpufreq_remove(struct platform_device *pdev)
+{
+ cpufreq_unregister_driver(&kirkwood_cpufreq_driver);
+
+ clk_disable_unprepare(priv.powersave_clk);
+ clk_disable_unprepare(priv.ddr_clk);
+ clk_disable_unprepare(priv.cpu_clk);
+
+ return 0;
+}
+
+static struct platform_driver kirkwood_cpufreq_platform_driver = {
+ .probe = kirkwood_cpufreq_probe,
+ .remove = kirkwood_cpufreq_remove,
+ .driver = {
+ .name = "kirkwood-cpufreq",
+ .owner = THIS_MODULE,
+ },
+};
+
+module_platform_driver(kirkwood_cpufreq_platform_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch");
+MODULE_DESCRIPTION("cpufreq driver for Marvell's kirkwood CPU");
+MODULE_ALIAS("platform:kirkwood-cpufreq");
--
1.7.10.4
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 2/3] arm: kirkwood: Instantiate cpufreq driver
2013-01-18 14:20 [PATCH 0/3] Kirkwoode cpufreq driver Andrew Lunn
2013-01-18 14:20 ` [PATCH 1/3] cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs Andrew Lunn
@ 2013-01-18 14:20 ` Andrew Lunn
2013-01-18 14:20 ` [PATCH 3/3] arm: kirkwood: Enable cpufreq and ondemand on kirkwood_defconfig Andrew Lunn
2 siblings, 0 replies; 7+ messages in thread
From: Andrew Lunn @ 2013-01-18 14:20 UTC (permalink / raw)
To: linux-arm-kernel
Register a platform driver structure for the cpufreq driver.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
arch/arm/Kconfig | 1 +
arch/arm/mach-kirkwood/board-dt.c | 3 ++-
arch/arm/mach-kirkwood/common.c | 23 +++++++++++++++++++++
arch/arm/mach-kirkwood/common.h | 2 ++
arch/arm/mach-kirkwood/include/mach/bridge-regs.h | 2 ++
5 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 67874b8..830975b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -543,6 +543,7 @@ config ARCH_DOVE
config ARCH_KIRKWOOD
bool "Marvell Kirkwood"
+ select ARCH_HAS_CPUFREQ
select ARCH_REQUIRE_GPIOLIB
select CPU_FEROCEON
select GENERIC_CLOCKEVENTS
diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
index de4fd2b..fab541d 100644
--- a/arch/arm/mach-kirkwood/board-dt.c
+++ b/arch/arm/mach-kirkwood/board-dt.c
@@ -70,7 +70,6 @@ static void __init kirkwood_legacy_clk_init(void)
clkspec.args[0] = CGC_BIT_SDIO;
orion_clkdev_add(NULL, "mvsdio",
of_clk_get_from_provider(&clkspec));
-
}
static void __init kirkwood_of_clk_init(void)
@@ -95,6 +94,8 @@ static void __init kirkwood_dt_init(void)
kirkwood_l2_init();
+ kirkwood_cpufreq_init();
+
/* Setup root of clk tree */
kirkwood_of_clk_init();
diff --git a/arch/arm/mach-kirkwood/common.c b/arch/arm/mach-kirkwood/common.c
index bac21a5..a3dc21c 100644
--- a/arch/arm/mach-kirkwood/common.c
+++ b/arch/arm/mach-kirkwood/common.c
@@ -584,6 +584,29 @@ void __init kirkwood_audio_init(void)
}
/*****************************************************************************
+ * CPU Frequency
+ ****************************************************************************/
+static struct resource kirkwood_cpufreq_resources[] = {
+ [0] = {
+ .start = CPU_CONTROL_PHYS,
+ .end = CPU_CONTROL_PHYS + 3,
+ .flags = IORESOURCE_MEM,
+ },
+};
+
+static struct platform_device kirkwood_cpufreq_device = {
+ .name = "kirkwood-cpufreq",
+ .id = -1,
+ .num_resources = ARRAY_SIZE(kirkwood_cpufreq_resources),
+ .resource = kirkwood_cpufreq_resources,
+};
+
+void __init kirkwood_cpufreq_init(void)
+{
+ platform_device_register(&kirkwood_cpufreq_device);
+}
+
+/*****************************************************************************
* General
****************************************************************************/
/*
diff --git a/arch/arm/mach-kirkwood/common.h b/arch/arm/mach-kirkwood/common.h
index 5ffa57f..9ede04b 100644
--- a/arch/arm/mach-kirkwood/common.h
+++ b/arch/arm/mach-kirkwood/common.h
@@ -50,6 +50,8 @@ void kirkwood_nand_init(struct mtd_partition *parts, int nr_parts, int delay);
void kirkwood_nand_init_rnb(struct mtd_partition *parts, int nr_parts,
int (*dev_ready)(struct mtd_info *));
void kirkwood_audio_init(void);
+void kirkwood_cpufreq_init(void);
+
void kirkwood_restart(char, const char *);
void kirkwood_clk_init(void);
diff --git a/arch/arm/mach-kirkwood/include/mach/bridge-regs.h b/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
index 5c82b7d..d4cbe5e 100644
--- a/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
+++ b/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
@@ -17,6 +17,7 @@
#define CPU_CONFIG_ERROR_PROP 0x00000004
#define CPU_CONTROL (BRIDGE_VIRT_BASE + 0x0104)
+#define CPU_CONTROL_PHYS (BRIDGE_PHYS_BASE + 0x0104)
#define CPU_RESET 0x00000002
#define RSTOUTn_MASK (BRIDGE_VIRT_BASE + 0x0108)
@@ -69,6 +70,7 @@
#define CGC_RUNIT (1 << 7)
#define CGC_XOR0 (1 << 8)
#define CGC_AUDIO (1 << 9)
+#define CGC_POWERSAVE (1 << 11)
#define CGC_SATA0 (1 << 14)
#define CGC_SATA1 (1 << 15)
#define CGC_XOR1 (1 << 16)
--
1.7.10.4
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 3/3] arm: kirkwood: Enable cpufreq and ondemand on kirkwood_defconfig
2013-01-18 14:20 [PATCH 0/3] Kirkwoode cpufreq driver Andrew Lunn
2013-01-18 14:20 ` [PATCH 1/3] cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs Andrew Lunn
2013-01-18 14:20 ` [PATCH 2/3] arm: kirkwood: Instantiate cpufreq driver Andrew Lunn
@ 2013-01-18 14:20 ` Andrew Lunn
2 siblings, 0 replies; 7+ messages in thread
From: Andrew Lunn @ 2013-01-18 14:20 UTC (permalink / raw)
To: linux-arm-kernel
Now that we have a cpufreq driver for kirkwood, enable it in
kirkwood_defconfig and set the default governer to ondemand.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
arch/arm/configs/kirkwood_defconfig | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm/configs/kirkwood_defconfig b/arch/arm/configs/kirkwood_defconfig
index 93f3794..6ecb7de 100644
--- a/arch/arm/configs/kirkwood_defconfig
+++ b/arch/arm/configs/kirkwood_defconfig
@@ -55,6 +55,9 @@ CONFIG_AEABI=y
# CONFIG_OABI_COMPAT is not set
CONFIG_ZBOOT_ROM_TEXT=0x0
CONFIG_ZBOOT_ROM_BSS=0x0
+CONFIG_CPU_FREQ=y
+CONFIG_CPU_FREQ_STAT_DETAILS=y
+CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y
CONFIG_CPU_IDLE=y
CONFIG_NET=y
CONFIG_PACKET=y
--
1.7.10.4
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 1/3] cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs
2013-01-18 14:20 ` [PATCH 1/3] cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs Andrew Lunn
@ 2013-01-18 14:39 ` Peter Korsgaard
2013-01-20 4:11 ` Viresh Kumar
1 sibling, 0 replies; 7+ messages in thread
From: Peter Korsgaard @ 2013-01-18 14:39 UTC (permalink / raw)
To: linux-arm-kernel
>>>>> "Andrew" == Andrew Lunn <andrew@lunn.ch> writes:
Andrew> The Marvell Kirkwood SoCs have simple cpufreq support in hardware. The
Andrew> CPU can either use the a high speed cpu clock, or the slower DDR
Andrew> clock. Add a driver to swap between these two clock sources.
Andrew> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Andrew> ---
Andrew> drivers/clk/mvebu/clk-gating-ctrl.c | 1 +
Andrew> drivers/cpufreq/Kconfig.arm | 6 +
Andrew> drivers/cpufreq/Makefile | 1 +
Andrew> drivers/cpufreq/kirkwood-cpufreq.c | 273 +++++++++++++++++++++++++++++++++++
Andrew> 4 files changed, 281 insertions(+)
Andrew> create mode 100644 drivers/cpufreq/kirkwood-cpufreq.c
Andrew> +++ b/drivers/cpufreq/Kconfig.arm
Andrew> @@ -77,6 +77,12 @@ config ARM_EXYNOS5250_CPUFREQ
Andrew> This adds the CPUFreq driver for Samsung EXYNOS5250
Andrew> SoC.
Andrew> +config ARM_KIRKWOOD_CPUFREQ
Andrew> + def_bool ARCH_KIRKWOOD && OF
Andrew> + help
The def_bool should be indented with a <tab>
Otherwise looks good.
--
Bye, Peter Korsgaard
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 1/3] cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs
2013-01-18 14:20 ` [PATCH 1/3] cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs Andrew Lunn
2013-01-18 14:39 ` Peter Korsgaard
@ 2013-01-20 4:11 ` Viresh Kumar
2013-01-20 8:35 ` Andrew Lunn
1 sibling, 1 reply; 7+ messages in thread
From: Viresh Kumar @ 2013-01-20 4:11 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Jan 18, 2013 at 7:50 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> The Marvell Kirkwood SoCs have simple cpufreq support in hardware. The
> CPU can either use the a high speed cpu clock, or the slower DDR
> clock. Add a driver to swap between these two clock sources.
>
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> ---
> drivers/clk/mvebu/clk-gating-ctrl.c | 1 +
> drivers/cpufreq/Kconfig.arm | 6 +
> drivers/cpufreq/Makefile | 1 +
> drivers/cpufreq/kirkwood-cpufreq.c | 273 +++++++++++++++++++++++++++++++++++
> 4 files changed, 281 insertions(+)
> create mode 100644 drivers/cpufreq/kirkwood-cpufreq.c
>
> diff --git a/drivers/clk/mvebu/clk-gating-ctrl.c b/drivers/clk/mvebu/clk-gating-ctrl.c
> index 8fa5408..ebf141d 100644
> --- a/drivers/clk/mvebu/clk-gating-ctrl.c
> +++ b/drivers/clk/mvebu/clk-gating-ctrl.c
> @@ -193,6 +193,7 @@ static const struct mvebu_soc_descr __initconst kirkwood_gating_descr[] = {
> { "runit", NULL, 7 },
> { "xor0", NULL, 8 },
> { "audio", NULL, 9 },
> + { "powersave", "cpuclk", 11 },
> { "sata0", NULL, 14 },
> { "sata1", NULL, 15 },
> { "xor1", NULL, 16 },
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index a0b3661..08ca366 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -77,6 +77,12 @@ config ARM_EXYNOS5250_CPUFREQ
> This adds the CPUFreq driver for Samsung EXYNOS5250
> SoC.
>
> +config ARM_KIRKWOOD_CPUFREQ
> + def_bool ARCH_KIRKWOOD && OF
> + help
> + This adds the CPUFreq driver for Marvell Kirkwood
> + SoCs.
> +
> config ARM_SPEAR_CPUFREQ
> bool "SPEAr CPUFreq support"
> depends on PLAT_SPEAR
> diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
> index fadc4d4..39a0ffe 100644
> --- a/drivers/cpufreq/Makefile
> +++ b/drivers/cpufreq/Makefile
> @@ -50,6 +50,7 @@ obj-$(CONFIG_ARM_EXYNOS_CPUFREQ) += exynos-cpufreq.o
> obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) += exynos4210-cpufreq.o
> obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ) += exynos4x12-cpufreq.o
> obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ) += exynos5250-cpufreq.o
> +obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ) += kirkwood-cpufreq.o
> obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o
> obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o
>
> diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
> new file mode 100644
> index 0000000..4f0a435
> --- /dev/null
> +++ b/drivers/cpufreq/kirkwood-cpufreq.c
> @@ -0,0 +1,273 @@
> +/*
> + * kirkwood_freq.c: cpufreq driver for the Marvell kirkwood
> + *
> + * 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/init.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk-provider.h>
why do you need this one?
> +#include <linux/of.h>
> +#include <linux/delay.h>
> +#include <linux/clk.h>
> +#include <linux/cpufreq.h>
> +#include <linux/timex.h>
> +#include <linux/io.h>
> +#include <asm/proc-fns.h>
would be better to keep them in alphabetical order to guarantee that we don't
include anything twice.
> +#define CPU_SW_INT_BLK BIT(28)
> +
> +
> +#include <linux/clk-private.h>
> +
> +static struct priv
> +{
> + struct clk *cpu_clk;
> + struct clk *ddr_clk;
> + struct clk *powersave_clk;
> + struct device *dev;
> + void __iomem *base;
> +} priv;
> +
> +#define STATE_CPU_FREQ 0x01
> +#define STATE_DDR_FREQ 0x02
> +
> +/* Kirkwood can swap the clock to the CPU between two clocks:
> + *
> + * - cpu clk
> + * - ddr clk
> + *
> + * The frequencies are set at runtime before registering this *
> + * table. */
wrong multiline comment style.
/*
* ....
* ....
*/
> +static struct cpufreq_frequency_table kirkwood_freq_table[] = {
> + {STATE_CPU_FREQ, 0}, /* CPU uses cpuclk */
> + {STATE_DDR_FREQ, 0}, /* CPU uses ddrclk */
> + {0, CPUFREQ_TABLE_END},
> +};
I don't know if anything is broken now, but i would like to keep index
in freq_table.index
field as the actual index in the table.
i.e, currently you have order as 1,2,0 .. but should have been 0, 1, 2
> +static unsigned int kirkwood_cpufreq_get_cpu_frequency(unsigned int cpu)
> +{
> + if (__clk_is_enabled(priv.powersave_clk))
> + return kirkwood_freq_table[1].frequency;
> + return kirkwood_freq_table[0].frequency;
> +}
> +
> +static void kirkwood_cpufreq_set_cpu_state(unsigned int index)
> +{
> +
> + struct cpufreq_freqs freqs;
> + unsigned int state = kirkwood_freq_table[index].index;
> + unsigned long reg;
> +
> + freqs.old = kirkwood_cpufreq_get_cpu_frequency(0);
> + freqs.new = kirkwood_freq_table[index].frequency;
> + freqs.cpu = 0; /* Kirkwood is UP */
> +
> + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
> +
> + dev_dbg(priv.dev, "Attempting to set frequency to %i KHz\n",
> + kirkwood_freq_table[index].frequency);
> + dev_dbg(priv.dev, "old frequency was %i KHz\n",
> + kirkwood_cpufreq_get_cpu_frequency(0));
> +
> + if (freqs.old != freqs.new) {
> + local_irq_disable();
> +
> + /* Disable interrupts to the CPU */
> + reg = readl_relaxed(priv.base);
> + reg |= CPU_SW_INT_BLK;
> + writel(reg, priv.base);
> +
> + switch (state) {
> + case STATE_CPU_FREQ:
> + clk_disable(priv.powersave_clk);
> + break;
> + case STATE_DDR_FREQ:
> + clk_enable(priv.powersave_clk);
> + break;
> + default:
> + dev_err(priv.dev, "Unexpected cpufreq state");
> + }
> +
> + /* Wait-for-Interrupt, which the hardware changes frequency */
> + cpu_do_idle();
> +
> + /* Enable interrupts to the CPU */
> + reg = readl_relaxed(priv.base);
> + reg &= ~CPU_SW_INT_BLK;
> + writel(reg, priv.base);
> +
> + local_irq_enable();
> + }
> + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
> +};
> +
> +static int kirkwood_cpufreq_verify(struct cpufreq_policy *policy)
> +{
> + return cpufreq_frequency_table_verify(policy, &kirkwood_freq_table[0]);
> +}
> +
> +static int kirkwood_cpufreq_target(struct cpufreq_policy *policy,
> + unsigned int target_freq,
> + unsigned int relation)
> +{
> + unsigned int index = 0;
> +
> + if (cpufreq_frequency_table_target(policy, kirkwood_freq_table,
> + target_freq, relation, &index))
> + return -EINVAL;
> +
> + kirkwood_cpufreq_set_cpu_state(index);
You can get this function inlined here.. as it is only called from
this location.
> + return 0;
> +}
> +
> +/*
> + * Module init and exit code
> + */
> +static int kirkwood_cpufreq_cpu_init(struct cpufreq_policy *policy)
> +{
> + int result;
> +
> + /* cpuinfo and default policy values */
> + policy->cpuinfo.transition_latency = 5000; /* 5uS */
> + policy->cur = kirkwood_cpufreq_get_cpu_frequency(0);
> +
> + result = cpufreq_frequency_table_cpuinfo(policy, kirkwood_freq_table);
> + if (result)
> + return result;
> +
> + cpufreq_frequency_table_get_attr(kirkwood_freq_table, policy->cpu);
> +
> + return 0;
> +}
> +
> +static int kirkwood_cpufreq_cpu_exit(struct cpufreq_policy *policy)
> +{
> + cpufreq_frequency_table_put_attr(policy->cpu);
> + return 0;
> +}
> +
> +static struct freq_attr *kirkwood_cpufreq_attr[] = {
> + &cpufreq_freq_attr_scaling_available_freqs,
> + NULL,
> +};
> +
> +
> +static struct cpufreq_driver kirkwood_cpufreq_driver = {
> + .get = kirkwood_cpufreq_get_cpu_frequency,
> + .verify = kirkwood_cpufreq_verify,
> + .target = kirkwood_cpufreq_target,
> + .init = kirkwood_cpufreq_cpu_init,
> + .exit = kirkwood_cpufreq_cpu_exit,
> + .name = "kirkwood_freq",
> + .owner = THIS_MODULE,
> + .attr = kirkwood_cpufreq_attr,
> +};
> +
> +static int kirkwood_cpufreq_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = of_find_compatible_node(
> + NULL, NULL, "marvell,kirkwood-core-clock");
Is cpu0 a better location for adding this entry?
> + struct of_phandle_args clkspec;
> + struct resource *res;
> + int err;
> +
> + priv.dev = &pdev->dev;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "Cannot get memory resource\n");
> + return -ENODEV;
> + }
> + priv.base = devm_request_and_ioremap(&pdev->dev, res);
> + if (!priv.base) {
> + dev_err(&pdev->dev, "Cannot ioremap\n");
> + return -ENOMEM;
> + }
> +
> + clkspec.np = np;
> + clkspec.args_count = 1;
> + clkspec.args[0] = 1;
> +
> + priv.cpu_clk = of_clk_get_from_provider(&clkspec);
> + if (IS_ERR(priv.cpu_clk)) {
> + dev_err(priv.dev, "Unable to get cpuclk");
> + return PTR_ERR(priv.cpu_clk);
> + }
> +
> + clk_prepare_enable(priv.cpu_clk);
> + kirkwood_freq_table[0].frequency = clk_get_rate(priv.cpu_clk) / 1000;
> +
> + clkspec.args[0] = 3;
> + priv.ddr_clk = of_clk_get_from_provider(&clkspec);
> + if (IS_ERR(priv.ddr_clk)) {
> + dev_err(priv.dev, "Unable to get ddrclk");
> + err = PTR_ERR(priv.ddr_clk);
> + goto out_cpu;
> + }
> +
> + clk_prepare_enable(priv.ddr_clk);
> + kirkwood_freq_table[1].frequency = clk_get_rate(priv.ddr_clk) / 1000;
> +
> + np = of_find_compatible_node(NULL, NULL,
> + "marvell,kirkwood-gating-clock");
> + clkspec.np = np;
> + clkspec.args[0] = 11;
> + priv.powersave_clk = of_clk_get_from_provider(&clkspec);
> + if (IS_ERR(priv.powersave_clk)) {
> + dev_err(priv.dev, "Unable to get powersave");
> + err = PTR_ERR(priv.powersave_clk);
> + goto out_ddr;
> + }
> + clk_prepare(priv.powersave_clk);
want to check return value?
> + err = cpufreq_register_driver(&kirkwood_cpufreq_driver);
> + if (!err)
> + return 0;
> + dev_err(priv.dev, "Failed to register cpufreq driver");
> +
> + clk_disable_unprepare(priv.powersave_clk);
> +out_ddr:
> + clk_disable_unprepare(priv.ddr_clk);
> +out_cpu:
> + clk_disable_unprepare(priv.cpu_clk);
> +
> + return err;
> +}
> +
> +
> +static int kirkwood_cpufreq_remove(struct platform_device *pdev)
> +{
> + cpufreq_unregister_driver(&kirkwood_cpufreq_driver);
> +
> + clk_disable_unprepare(priv.powersave_clk);
> + clk_disable_unprepare(priv.ddr_clk);
> + clk_disable_unprepare(priv.cpu_clk);
> +
> + return 0;
> +}
> +
> +static struct platform_driver kirkwood_cpufreq_platform_driver = {
> + .probe = kirkwood_cpufreq_probe,
> + .remove = kirkwood_cpufreq_remove,
> + .driver = {
> + .name = "kirkwood-cpufreq",
> + .owner = THIS_MODULE,
> + },
> +};
> +
> +module_platform_driver(kirkwood_cpufreq_platform_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch");
> +MODULE_DESCRIPTION("cpufreq driver for Marvell's kirkwood CPU");
> +MODULE_ALIAS("platform:kirkwood-cpufreq");
> --
> 1.7.10.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe cpufreq" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 1/3] cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs
2013-01-20 4:11 ` Viresh Kumar
@ 2013-01-20 8:35 ` Andrew Lunn
0 siblings, 0 replies; 7+ messages in thread
From: Andrew Lunn @ 2013-01-20 8:35 UTC (permalink / raw)
To: linux-arm-kernel
On Sun, Jan 20, 2013 at 09:41:34AM +0530, Viresh Kumar wrote:
> On Fri, Jan 18, 2013 at 7:50 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> > The Marvell Kirkwood SoCs have simple cpufreq support in hardware. The
> > CPU can either use the a high speed cpu clock, or the slower DDR
> > clock. Add a driver to swap between these two clock sources.
> >
> > Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> > ---
> > drivers/clk/mvebu/clk-gating-ctrl.c | 1 +
> > drivers/cpufreq/Kconfig.arm | 6 +
> > drivers/cpufreq/Makefile | 1 +
> > drivers/cpufreq/kirkwood-cpufreq.c | 273 +++++++++++++++++++++++++++++++++++
> > 4 files changed, 281 insertions(+)
> > create mode 100644 drivers/cpufreq/kirkwood-cpufreq.c
> >
> > diff --git a/drivers/clk/mvebu/clk-gating-ctrl.c b/drivers/clk/mvebu/clk-gating-ctrl.c
> > index 8fa5408..ebf141d 100644
> > --- a/drivers/clk/mvebu/clk-gating-ctrl.c
> > +++ b/drivers/clk/mvebu/clk-gating-ctrl.c
> > @@ -193,6 +193,7 @@ static const struct mvebu_soc_descr __initconst kirkwood_gating_descr[] = {
> > { "runit", NULL, 7 },
> > { "xor0", NULL, 8 },
> > { "audio", NULL, 9 },
> > + { "powersave", "cpuclk", 11 },
> > { "sata0", NULL, 14 },
> > { "sata1", NULL, 15 },
> > { "xor1", NULL, 16 },
> > diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> > index a0b3661..08ca366 100644
> > --- a/drivers/cpufreq/Kconfig.arm
> > +++ b/drivers/cpufreq/Kconfig.arm
> > @@ -77,6 +77,12 @@ config ARM_EXYNOS5250_CPUFREQ
> > This adds the CPUFreq driver for Samsung EXYNOS5250
> > SoC.
> >
> > +config ARM_KIRKWOOD_CPUFREQ
> > + def_bool ARCH_KIRKWOOD && OF
> > + help
> > + This adds the CPUFreq driver for Marvell Kirkwood
> > + SoCs.
> > +
> > config ARM_SPEAR_CPUFREQ
> > bool "SPEAr CPUFreq support"
> > depends on PLAT_SPEAR
> > diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
> > index fadc4d4..39a0ffe 100644
> > --- a/drivers/cpufreq/Makefile
> > +++ b/drivers/cpufreq/Makefile
> > @@ -50,6 +50,7 @@ obj-$(CONFIG_ARM_EXYNOS_CPUFREQ) += exynos-cpufreq.o
> > obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) += exynos4210-cpufreq.o
> > obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ) += exynos4x12-cpufreq.o
> > obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ) += exynos5250-cpufreq.o
> > +obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ) += kirkwood-cpufreq.o
> > obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o
> > obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o
> >
> > diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
> > new file mode 100644
> > index 0000000..4f0a435
> > --- /dev/null
> > +++ b/drivers/cpufreq/kirkwood-cpufreq.c
> > @@ -0,0 +1,273 @@
> > +/*
> > + * kirkwood_freq.c: cpufreq driver for the Marvell kirkwood
> > + *
> > + * 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/init.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/clk-provider.h>
>
> why do you need this one?
I need __clk_is_enabled() in order to know the current state of the
clock. What i found is that if the state does not change, the CPU
never wakes up from the WFI. So i want to read back from the hardware
what state the clock is in.
>
> > +#include <linux/of.h>
> > +#include <linux/delay.h>
> > +#include <linux/clk.h>
> > +#include <linux/cpufreq.h>
> > +#include <linux/timex.h>
> > +#include <linux/io.h>
> > +#include <asm/proc-fns.h>
>
> would be better to keep them in alphabetical order to guarantee that we don't
> include anything twice.
O.K.
> > +#define CPU_SW_INT_BLK BIT(28)
> > +
> > +
> > +#include <linux/clk-private.h>
> > +
> > +static struct priv
> > +{
> > + struct clk *cpu_clk;
> > + struct clk *ddr_clk;
> > + struct clk *powersave_clk;
> > + struct device *dev;
> > + void __iomem *base;
> > +} priv;
> > +
> > +#define STATE_CPU_FREQ 0x01
> > +#define STATE_DDR_FREQ 0x02
> > +
> > +/* Kirkwood can swap the clock to the CPU between two clocks:
> > + *
> > + * - cpu clk
> > + * - ddr clk
> > + *
> > + * The frequencies are set at runtime before registering this *
> > + * table. */
>
> wrong multiline comment style.
>
> /*
> * ....
> * ....
> */
>
> > +static struct cpufreq_frequency_table kirkwood_freq_table[] = {
> > + {STATE_CPU_FREQ, 0}, /* CPU uses cpuclk */
> > + {STATE_DDR_FREQ, 0}, /* CPU uses ddrclk */
> > + {0, CPUFREQ_TABLE_END},
> > +};
>
> I don't know if anything is broken now, but i would like to keep index
> in freq_table.index
> field as the actual index in the table.
>
> i.e, currently you have order as 1,2,0 .. but should have been 0, 1, 2
Documentation/cpu-freq/cpu-drivers.txt says:
2. Frequency Table Helpers
==========================
As most cpufreq processors only allow for being set to a few specific
frequencies, a "frequency table" with some functions might assist in
some work of the processor driver. Such a "frequency table" consists
of an array of struct cpufreq_freq_table entries, with any value in
"index" you want to use, and the corresponding frequency in
"frequency". At the end of the table, you need to add a
cpufreq_freq_table entry with frequency set to CPUFREQ_TABLE_END. And
if you want to skip one entry in the table, set the frequency to
CPUFREQ_ENTRY_INVALID. The entries don't need to be in ascending
order.
> > +static unsigned int kirkwood_cpufreq_get_cpu_frequency(unsigned int cpu)
> > +{
> > + if (__clk_is_enabled(priv.powersave_clk))
> > + return kirkwood_freq_table[1].frequency;
> > + return kirkwood_freq_table[0].frequency;
> > +}
> > +
> > +static void kirkwood_cpufreq_set_cpu_state(unsigned int index)
> > +{
> > +
> > + struct cpufreq_freqs freqs;
> > + unsigned int state = kirkwood_freq_table[index].index;
> > + unsigned long reg;
> > +
> > + freqs.old = kirkwood_cpufreq_get_cpu_frequency(0);
> > + freqs.new = kirkwood_freq_table[index].frequency;
> > + freqs.cpu = 0; /* Kirkwood is UP */
> > +
> > + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
> > +
> > + dev_dbg(priv.dev, "Attempting to set frequency to %i KHz\n",
> > + kirkwood_freq_table[index].frequency);
> > + dev_dbg(priv.dev, "old frequency was %i KHz\n",
> > + kirkwood_cpufreq_get_cpu_frequency(0));
> > +
> > + if (freqs.old != freqs.new) {
> > + local_irq_disable();
> > +
> > + /* Disable interrupts to the CPU */
> > + reg = readl_relaxed(priv.base);
> > + reg |= CPU_SW_INT_BLK;
> > + writel(reg, priv.base);
> > +
> > + switch (state) {
> > + case STATE_CPU_FREQ:
> > + clk_disable(priv.powersave_clk);
> > + break;
> > + case STATE_DDR_FREQ:
> > + clk_enable(priv.powersave_clk);
> > + break;
> > + default:
> > + dev_err(priv.dev, "Unexpected cpufreq state");
> > + }
> > +
> > + /* Wait-for-Interrupt, which the hardware changes frequency */
> > + cpu_do_idle();
> > +
> > + /* Enable interrupts to the CPU */
> > + reg = readl_relaxed(priv.base);
> > + reg &= ~CPU_SW_INT_BLK;
> > + writel(reg, priv.base);
> > +
> > + local_irq_enable();
> > + }
> > + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
> > +};
> > +
> > +static int kirkwood_cpufreq_verify(struct cpufreq_policy *policy)
> > +{
> > + return cpufreq_frequency_table_verify(policy, &kirkwood_freq_table[0]);
> > +}
> > +
> > +static int kirkwood_cpufreq_target(struct cpufreq_policy *policy,
> > + unsigned int target_freq,
> > + unsigned int relation)
> > +{
> > + unsigned int index = 0;
> > +
> > + if (cpufreq_frequency_table_target(policy, kirkwood_freq_table,
> > + target_freq, relation, &index))
> > + return -EINVAL;
> > +
> > + kirkwood_cpufreq_set_cpu_state(index);
>
> You can get this function inlined here.. as it is only called from
> this location.
Yes, i could. gcc will inline it anyway. But look at other
drivers. elan, gx-suspmod, longhaul, maple, p4, powernow-k6,
powernow-k7, powernow-k8, etc, all have a helper function to do the
actual change, which is called from the target function. So i'm just
following the normal convention.
> > + return 0;
> > +}
> > +
> > +/*
> > + * Module init and exit code
> > + */
> > +static int kirkwood_cpufreq_cpu_init(struct cpufreq_policy *policy)
> > +{
> > + int result;
> > +
> > + /* cpuinfo and default policy values */
> > + policy->cpuinfo.transition_latency = 5000; /* 5uS */
> > + policy->cur = kirkwood_cpufreq_get_cpu_frequency(0);
> > +
> > + result = cpufreq_frequency_table_cpuinfo(policy, kirkwood_freq_table);
> > + if (result)
> > + return result;
> > +
> > + cpufreq_frequency_table_get_attr(kirkwood_freq_table, policy->cpu);
> > +
> > + return 0;
> > +}
> > +
> > +static int kirkwood_cpufreq_cpu_exit(struct cpufreq_policy *policy)
> > +{
> > + cpufreq_frequency_table_put_attr(policy->cpu);
> > + return 0;
> > +}
> > +
> > +static struct freq_attr *kirkwood_cpufreq_attr[] = {
> > + &cpufreq_freq_attr_scaling_available_freqs,
> > + NULL,
> > +};
> > +
> > +
> > +static struct cpufreq_driver kirkwood_cpufreq_driver = {
> > + .get = kirkwood_cpufreq_get_cpu_frequency,
> > + .verify = kirkwood_cpufreq_verify,
> > + .target = kirkwood_cpufreq_target,
> > + .init = kirkwood_cpufreq_cpu_init,
> > + .exit = kirkwood_cpufreq_cpu_exit,
> > + .name = "kirkwood_freq",
> > + .owner = THIS_MODULE,
> > + .attr = kirkwood_cpufreq_attr,
> > +};
> > +
> > +static int kirkwood_cpufreq_probe(struct platform_device *pdev)
> > +{
> > + struct device_node *np = of_find_compatible_node(
> > + NULL, NULL, "marvell,kirkwood-core-clock");
>
> Is cpu0 a better location for adding this entry?
I'm not adding an entry here. I'm using an existing entry.
> > + struct of_phandle_args clkspec;
> > + struct resource *res;
> > + int err;
> > +
> > + priv.dev = &pdev->dev;
> > +
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + if (!res) {
> > + dev_err(&pdev->dev, "Cannot get memory resource\n");
> > + return -ENODEV;
> > + }
> > + priv.base = devm_request_and_ioremap(&pdev->dev, res);
> > + if (!priv.base) {
> > + dev_err(&pdev->dev, "Cannot ioremap\n");
> > + return -ENOMEM;
> > + }
> > +
> > + clkspec.np = np;
> > + clkspec.args_count = 1;
> > + clkspec.args[0] = 1;
> > +
> > + priv.cpu_clk = of_clk_get_from_provider(&clkspec);
> > + if (IS_ERR(priv.cpu_clk)) {
> > + dev_err(priv.dev, "Unable to get cpuclk");
> > + return PTR_ERR(priv.cpu_clk);
> > + }
> > +
> > + clk_prepare_enable(priv.cpu_clk);
> > + kirkwood_freq_table[0].frequency = clk_get_rate(priv.cpu_clk) / 1000;
> > +
> > + clkspec.args[0] = 3;
> > + priv.ddr_clk = of_clk_get_from_provider(&clkspec);
> > + if (IS_ERR(priv.ddr_clk)) {
> > + dev_err(priv.dev, "Unable to get ddrclk");
> > + err = PTR_ERR(priv.ddr_clk);
> > + goto out_cpu;
> > + }
> > +
> > + clk_prepare_enable(priv.ddr_clk);
> > + kirkwood_freq_table[1].frequency = clk_get_rate(priv.ddr_clk) / 1000;
> > +
> > + np = of_find_compatible_node(NULL, NULL,
> > + "marvell,kirkwood-gating-clock");
> > + clkspec.np = np;
> > + clkspec.args[0] = 11;
> > + priv.powersave_clk = of_clk_get_from_provider(&clkspec);
> > + if (IS_ERR(priv.powersave_clk)) {
> > + dev_err(priv.dev, "Unable to get powersave");
> > + err = PTR_ERR(priv.powersave_clk);
> > + goto out_ddr;
> > + }
> > + clk_prepare(priv.powersave_clk);
>
> want to check return value?
Not much point. Gated clock drivers don't actually have a prepare
function, so it cannot fail. The parent clock is a fixed clock, which
also does not have a prepare function. All this call is doing is
updating the reference counters.
Andrew
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2013-01-20 8:35 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-01-18 14:20 [PATCH 0/3] Kirkwoode cpufreq driver Andrew Lunn
2013-01-18 14:20 ` [PATCH 1/3] cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs Andrew Lunn
2013-01-18 14:39 ` Peter Korsgaard
2013-01-20 4:11 ` Viresh Kumar
2013-01-20 8:35 ` Andrew Lunn
2013-01-18 14:20 ` [PATCH 2/3] arm: kirkwood: Instantiate cpufreq driver Andrew Lunn
2013-01-18 14:20 ` [PATCH 3/3] arm: kirkwood: Enable cpufreq and ondemand on kirkwood_defconfig Andrew Lunn
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