cpufreq: instantiate cpufreq-cpu0 as a platform_driver
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 highbank-cpufreq driver is also updated accordingly to adapt the
changes on cpufreq-cpu0.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Mark Langsdorf <mark.langsdorf@calxeda.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index e0a899f..cbcb21e 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -185,7 +185,7 @@
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 38ae178..a108f66 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>
@@ -177,7 +177,7 @@
.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;
@@ -192,23 +192,17 @@
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;
@@ -271,7 +265,24 @@
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@linaro.org>");
MODULE_DESCRIPTION("Generic CPU0 cpufreq driver");
diff --git a/drivers/cpufreq/highbank-cpufreq.c b/drivers/cpufreq/highbank-cpufreq.c
index 53f25e5..66e3a71 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 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 @@
goto out_put_node;
}
+ /* Instantiate cpufreq-cpu0 */
+ platform_device_register_full(&devinfo);
+
out_put_node:
of_node_put(np);
return ret;