ARM: shmobile: sh73a0: add CPUFreq support

This patch enables the use of the generic cpufreq-cpu0 driver on sh73a0.
Providing a regulator, a list of OPPs in DT, combined with a virtual
cpufreq-cpu0 platform device and a clock, attached to it is everything,
the cpufreq-cpu0 driver needs. The first sh73a0 platform, implementing
such CPUFreq support is kzm9g-reference.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/mach-shmobile/Kconfig

@@ -169,6 +169,8 @@ config MACH_KZM9D
 config MACH_KZM9G
 	bool "KZM-A9-GT board"
 	depends on ARCH_SH73A0
+	select ARCH_HAS_CPUFREQ
+	select ARCH_HAS_OPP
 	select ARCH_REQUIRE_GPIOLIB
 	select REGULATOR_FIXED_VOLTAGE if REGULATOR
 	select SND_SOC_AK4642 if SND_SIMPLE_CARD

arch/arm/mach-shmobile/setup-sh73a0.c

@@ -963,6 +963,8 @@ static const struct of_dev_auxdata sh73a0_auxdata_lookup[] __initconst = {
 
 void __init sh73a0_add_standard_devices_dt(void)
 {
+	struct platform_device_info devinfo = { .name = "cpufreq-cpu0", .id = -1, };
+
 	/* clocks are setup late during boot in the case of DT */
 	sh73a0_clock_init();
 
@@ -970,6 +972,9 @@ void __init sh73a0_add_standard_devices_dt(void)
 			     ARRAY_SIZE(sh73a0_devices_dt));
 	of_platform_populate(NULL, of_default_bus_match_table,
 			     sh73a0_auxdata_lookup, NULL);
+
+	/* Instantiate cpufreq-cpu0 */
+	platform_device_register_full(&devinfo);
 }
 
 static const char *sh73a0_boards_compat_dt[] __initdata = {