[PATCH v2] cpufreq: instantiate cpufreq-cpu0 as a platform_driver

Shawn Guo shawn.guo at linaro.org
Mon Jan 28 21:53:40 EST 2013


As multiplatform build is being adopted by more and more ARM platforms,
initcall function should be used very carefully.  For example, when
GENERIC_CPUFREQ_CPU0 is built in the kernel, cpu0_cpufreq_driver_init()
will be called on all the platforms to initialize cpufreq-cpu0 driver.

To eliminate this undesired the effect, the patch changes cpufreq-cpu0
driver to have it instantiated as a platform_driver.  Then it will only
run on platforms that create the platform_device "cpufreq-cpu0".

Along with the change, it also changes cpu_dev to be &pdev->dev,
so that managed functions can start working, and module build gets
supported too.

The existing users of cpufreq-cpu0 driver highbank and am33xx are also
updated accordingly to adapt the changes.

Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
Cc: Mark Langsdorf <mark.langsdorf at calxeda.com>
Cc: AnilKumar Ch <anilkumar at ti.com>
Cc: Tony Lindgren <tony at atomide.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
---
Changes since v1:
 * Migrate cpufreq-cpu0 users in the same patch

Rafael,

The patch is based on Mark's highbank-cpufreq series and Nishanth's
"PM / OPP : export symbol consolidation" sereis.

Mark, AnilKumar,

I only compile-tested it on highbank and omap2.  Please give it a test
no hardware to make sure cpufreq-cpu0 still works for you.  Thanks.

Shawn

 arch/arm/mach-omap2/board-generic.c   |    1 +
 arch/arm/mach-omap2/cclock33xx_data.c |    2 +-
 arch/arm/mach-omap2/common.h          |    1 +
 arch/arm/mach-omap2/io.c              |    7 +++++++
 drivers/cpufreq/Kconfig               |    2 +-
 drivers/cpufreq/cpufreq-cpu0.c        |   35 ++++++++++++++++++++++-----------
 drivers/cpufreq/highbank-cpufreq.c    |    5 +++++
 7 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/arch/arm/mach-omap2/board-generic.c b/arch/arm/mach-omap2/board-generic.c
index 53cb380b..b945480 100644
--- a/arch/arm/mach-omap2/board-generic.c
+++ b/arch/arm/mach-omap2/board-generic.c
@@ -139,6 +139,7 @@ DT_MACHINE_START(AM33XX_DT, "Generic AM33XX (Flattened Device Tree)")
 	.init_irq	= omap_intc_of_init,
 	.handle_irq	= omap3_intc_handle_irq,
 	.init_machine	= omap_generic_init,
+	.init_late	= am33xx_init_late,
 	.timer		= &omap3_am33xx_timer,
 	.dt_compat	= am33xx_boards_compat,
 MACHINE_END
diff --git a/arch/arm/mach-omap2/cclock33xx_data.c b/arch/arm/mach-omap2/cclock33xx_data.c
index ea64ad6..acb1620 100644
--- a/arch/arm/mach-omap2/cclock33xx_data.c
+++ b/arch/arm/mach-omap2/cclock33xx_data.c
@@ -850,7 +850,7 @@ static struct omap_clk am33xx_clks[] = {
 	CLK(NULL,	"dpll_core_m5_ck",	&dpll_core_m5_ck,	CK_AM33XX),
 	CLK(NULL,	"dpll_core_m6_ck",	&dpll_core_m6_ck,	CK_AM33XX),
 	CLK(NULL,	"dpll_mpu_ck",		&dpll_mpu_ck,	CK_AM33XX),
-	CLK("cpu0",	NULL,			&dpll_mpu_ck,	CK_AM33XX),
+	CLK("cpufreq-cpu0.0",	NULL,		&dpll_mpu_ck,	CK_AM33XX),
 	CLK(NULL,	"dpll_mpu_m2_ck",	&dpll_mpu_m2_ck,	CK_AM33XX),
 	CLK(NULL,	"dpll_ddr_ck",		&dpll_ddr_ck,	CK_AM33XX),
 	CLK(NULL,	"dpll_ddr_m2_ck",	&dpll_ddr_m2_ck,	CK_AM33XX),
diff --git a/arch/arm/mach-omap2/common.h b/arch/arm/mach-omap2/common.h
index 948bcaa..e3355df5 100644
--- a/arch/arm/mach-omap2/common.h
+++ b/arch/arm/mach-omap2/common.h
@@ -106,6 +106,7 @@ void omap2430_init_late(void);
 void omap3430_init_late(void);
 void omap35xx_init_late(void);
 void omap3630_init_late(void);
+void am33xx_init_late(void);
 void am35xx_init_late(void);
 void ti81xx_init_late(void);
 void omap4430_init_late(void);
diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c
index 2c3fdd6..7acfb8a 100644
--- a/arch/arm/mach-omap2/io.c
+++ b/arch/arm/mach-omap2/io.c
@@ -535,6 +535,13 @@ void __init omap3630_init_late(void)
 	omap2_clk_enable_autoidle_all();
 }
 
+void __init am33xx_init_late(void)
+{
+	struct platform_device_info devinfo = { .name = "cpufreq-cpu0", };
+
+	platform_device_register_full(&devinfo);
+}
+
 void __init am35xx_init_late(void)
 {
 	omap_mux_late_init();
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index ea512f4..774dc1c 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -180,7 +180,7 @@ config CPU_FREQ_GOV_CONSERVATIVE
 	  If in doubt, say N.
 
 config GENERIC_CPUFREQ_CPU0
-	bool "Generic CPU0 cpufreq driver"
+	tristate "Generic CPU0 cpufreq driver"
 	depends on HAVE_CLK && REGULATOR && PM_OPP && OF
 	select CPU_FREQ_TABLE
 	help
diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
index 90e9d73..519c2f7 100644
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ b/drivers/cpufreq/cpufreq-cpu0.c
@@ -12,12 +12,12 @@
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
 
 #include <linux/clk.h>
-#include <linux/cpu.h>
 #include <linux/cpufreq.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/opp.h>
+#include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 
@@ -174,7 +174,7 @@ static struct cpufreq_driver cpu0_cpufreq_driver = {
 	.attr = cpu0_cpufreq_attr,
 };
 
-static int cpu0_cpufreq_driver_init(void)
+static int cpu0_cpufreq_probe(struct platform_device *pdev)
 {
 	struct device_node *np;
 	int ret;
@@ -189,23 +189,17 @@ static int cpu0_cpufreq_driver_init(void)
 		return -ENOENT;
 	}
 
-	cpu_dev = get_cpu_device(0);
-	if (!cpu_dev) {
-		pr_err("failed to get cpu0 device\n");
-		ret = -ENODEV;
-		goto out_put_node;
-	}
-
+	cpu_dev = &pdev->dev;
 	cpu_dev->of_node = np;
 
-	cpu_clk = clk_get(cpu_dev, NULL);
+	cpu_clk = devm_clk_get(cpu_dev, NULL);
 	if (IS_ERR(cpu_clk)) {
 		ret = PTR_ERR(cpu_clk);
 		pr_err("failed to get cpu0 clock: %d\n", ret);
 		goto out_put_node;
 	}
 
-	cpu_reg = regulator_get(cpu_dev, "cpu0");
+	cpu_reg = devm_regulator_get(cpu_dev, "cpu0");
 	if (IS_ERR(cpu_reg)) {
 		pr_warn("failed to get cpu0 regulator\n");
 		cpu_reg = NULL;
@@ -266,7 +260,24 @@ out_put_node:
 	of_node_put(np);
 	return ret;
 }
-late_initcall(cpu0_cpufreq_driver_init);
+
+static int cpu0_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_driver(&cpu0_cpufreq_driver);
+	opp_free_cpufreq_table(cpu_dev, &freq_table);
+
+	return 0;
+}
+
+static struct platform_driver cpu0_cpufreq_platdrv = {
+	.driver = {
+		.name	= "cpufreq-cpu0",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= cpu0_cpufreq_probe,
+	.remove		= cpu0_cpufreq_remove,
+};
+module_platform_driver(cpu0_cpufreq_platdrv);
 
 MODULE_AUTHOR("Shawn Guo <shawn.guo at linaro.org>");
 MODULE_DESCRIPTION("Generic CPU0 cpufreq driver");
diff --git a/drivers/cpufreq/highbank-cpufreq.c b/drivers/cpufreq/highbank-cpufreq.c
index 2ea6276..0491f1f 100644
--- a/drivers/cpufreq/highbank-cpufreq.c
+++ b/drivers/cpufreq/highbank-cpufreq.c
@@ -20,6 +20,7 @@
 #include <linux/err.h>
 #include <linux/of.h>
 #include <linux/mailbox.h>
+#include <linux/platform_device.h>
 
 #define HB_CPUFREQ_CHANGE_NOTE	0x80000001
 #define HB_CPUFREQ_IPC_LEN	7
@@ -65,6 +66,7 @@ static struct notifier_block hb_cpufreq_clk_nb = {
 
 static int hb_cpufreq_driver_init(void)
 {
+	struct platform_device_info devinfo = { .name = "cpufreq-cpu0", };
 	struct device *cpu_dev;
 	struct clk *cpu_clk;
 	struct device_node *np;
@@ -104,6 +106,9 @@ static int hb_cpufreq_driver_init(void)
 		goto out_put_node;
 	}
 
+	/* Instantiate cpufreq-cpu0 */
+	platform_device_register_full(&devinfo);
+
 out_put_node:
 	of_node_put(np);
 	return ret;
-- 
1.7.9.5





More information about the linux-arm-kernel mailing list