cpufreq: probe the Integrator cpufreq driver from DT

This makes the Integrator cpufreq driver probe from the core
module device tree node through it's registered platforms
device, getting the memory base from the device tree,
remapping it and removing dependencies to <mach/platform.h>
and <mach/hardware.h> by moving the two affected CM
register offsets into the driver.
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/cpufreq/integrator-cpufreq.c

@@ -15,18 +15,19 @@
 #include <linux/smp.h>
 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 
-#include <mach/hardware.h>
-#include <mach/platform.h>
 #include <asm/mach-types.h>
 #include <asm/hardware/icst.h>
 
-static struct cpufreq_driver integrator_driver;
+static void __iomem *cm_base;
+/* The cpufreq driver only use the OSC register */
+#define INTEGRATOR_HDR_OSC_OFFSET       0x08
+#define INTEGRATOR_HDR_LOCK_OFFSET      0x14
 
-#define CM_ID  	__io_address(INTEGRATOR_HDR_ID)
-#define CM_OSC	__io_address(INTEGRATOR_HDR_OSC)
-#define CM_STAT __io_address(INTEGRATOR_HDR_STAT)
-#define CM_LOCK __io_address(INTEGRATOR_HDR_LOCK)
+static struct cpufreq_driver integrator_driver;
 
 static const struct icst_params lclk_params = {
 	.ref		= 24000000,
@@ -100,7 +101,7 @@ static int integrator_set_target(struct cpufreq_policy *policy,
 	BUG_ON(cpu != smp_processor_id());
 
 	/* get current setting */
-	cm_osc = __raw_readl(CM_OSC);
+	cm_osc = __raw_readl(cm_base + INTEGRATOR_HDR_OSC_OFFSET);
 
 	if (machine_is_integrator()) {
 		vco.s = (cm_osc >> 8) & 7;
@@ -128,7 +129,7 @@ static int integrator_set_target(struct cpufreq_policy *policy,
 
 	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
 
-	cm_osc = __raw_readl(CM_OSC);
+	cm_osc = __raw_readl(cm_base + INTEGRATOR_HDR_OSC_OFFSET);
 
 	if (machine_is_integrator()) {
 		cm_osc &= 0xfffff800;
@@ -138,9 +139,9 @@ static int integrator_set_target(struct cpufreq_policy *policy,
 	}
 	cm_osc |= vco.v;
 
-	__raw_writel(0xa05f, CM_LOCK);
-	__raw_writel(cm_osc, CM_OSC);
-	__raw_writel(0, CM_LOCK);
+	__raw_writel(0xa05f, cm_base + INTEGRATOR_HDR_LOCK_OFFSET);
+	__raw_writel(cm_osc, cm_base + INTEGRATOR_HDR_OSC_OFFSET);
+	__raw_writel(0, cm_base + INTEGRATOR_HDR_LOCK_OFFSET);
 
 	/*
 	 * Restore the CPUs allowed mask.
@@ -165,7 +166,7 @@ static unsigned int integrator_get(unsigned int cpu)
 	BUG_ON(cpu != smp_processor_id());
 
 	/* detect memory etc. */
-	cm_osc = __raw_readl(CM_OSC);
+	cm_osc = __raw_readl(cm_base + INTEGRATOR_HDR_OSC_OFFSET);
 
 	if (machine_is_integrator()) {
 		vco.s = (cm_osc >> 8) & 7;
@@ -202,19 +203,43 @@ static struct cpufreq_driver integrator_driver = {
 	.name		= "integrator",
 };
 
-static int __init integrator_cpu_init(void)
+static int __init integrator_cpufreq_probe(struct platform_device *pdev)
 {
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res)
+		return -ENODEV;
+
+	cm_base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (!cm_base)
+		return -ENODEV;
+
 	return cpufreq_register_driver(&integrator_driver);
 }
 
-static void __exit integrator_cpu_exit(void)
+static void __exit integrator_cpufreq_remove(struct platform_device *pdev)
 {
 	cpufreq_unregister_driver(&integrator_driver);
 }
 
+static const struct of_device_id integrator_cpufreq_match[] = {
+	{ .compatible = "arm,core-module-integrator"},
+	{ },
+};
+
+static struct platform_driver integrator_cpufreq_driver = {
+	.driver = {
+		.name = "integrator-cpufreq",
+		.owner = THIS_MODULE,
+		.of_match_table = integrator_cpufreq_match,
+	},
+	.remove = __exit_p(integrator_cpufreq_remove),
+};
+
+module_platform_driver_probe(integrator_cpufreq_driver,
+			     integrator_cpufreq_probe);
+
 MODULE_AUTHOR ("Russell M. King");
 MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs");
 MODULE_LICENSE ("GPL");
-
-module_init(integrator_cpu_init);
-module_exit(integrator_cpu_exit);