[PATCH/RFC 4/4] ARM: shmobile: lager: add CPUFreq support

[Guennadi Liakhovetski]

The Lager board uses a DA9210 voltage regulator to supply DVFS power to the
CA15 cores on the r8a7790 SoC. This patch adds CPUFreq support for that
board using the cpufreq-cpu0 driver.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@xxxxxxxxx>
---

This patch is marked as RFC, because so far I don't have data about r8a7790
valid OPPs. The Lager system boots with 1.3GHz, supplying 1.0V to SoC's
DVFS. Apart from that I don't have information what voltage is required for
other clock frequencies. Here I'm using a "safe guess" of 0.95V for 700MHz,
but we might either wait with this patch until exact data is available, or
actually commit these values - this can be decided.

 arch/arm/boot/dts/r8a7790-lager-reference.dts  |   32 ++++++++++++++++++++++++
 arch/arm/mach-shmobile/board-lager-reference.c |    4 ++-
 2 files changed, 35 insertions(+), 1 deletions(-)

diff --git a/arch/arm/boot/dts/r8a7790-lager-reference.dts b/arch/arm/boot/dts/r8a7790-lager-reference.dts
index c462ef1..7a41419 100644
--- a/arch/arm/boot/dts/r8a7790-lager-reference.dts
+++ b/arch/arm/boot/dts/r8a7790-lager-reference.dts
@@ -43,3 +43,35 @@
 		};
 	};
 };
+
+&i2c3 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2c3_pins>;
+
+	vdd_dvfs: da9210@68 {
+		compatible = "diasemi,da9210";
+		reg = <0x68>;
+
+		regulator-min-microvolt = <900000>;
+		regulator-max-microvolt = <1000000>;
+		regulator-boot-on;
+		regulator-always-on;
+	};
+};
+
+&cpu0 {
+	cpu0-supply = <&vdd_dvfs>;
+	operating-points = <
+		/* kHz  uV - OPs unknown yet */
+		1300000 1000000
+		 700000  950000
+	>;
+	voltage-tolerance = <1>; /* 1% */
+};
+
+&pfc {
+	i2c3_pins: i2c3 {
+		renesas,groups = "i2c3";
+		renesas,function = "i2c3";
+	};
+};
diff --git a/arch/arm/mach-shmobile/board-lager-reference.c b/arch/arm/mach-shmobile/board-lager-reference.c
index 9c316a1..442d854 100644
--- a/arch/arm/mach-shmobile/board-lager-reference.c
+++ b/arch/arm/mach-shmobile/board-lager-reference.c
@@ -20,6 +20,7 @@
 
 #include <linux/init.h>
 #include <linux/of_platform.h>
+#include <linux/platform_device.h>
 #include <mach/r8a7790.h>
 #include <asm/mach/arch.h>
 
@@ -29,7 +30,8 @@ static void __init lager_add_standard_devices(void)
 	r8a7790_clock_init();
 
 	r8a7790_add_dt_devices();
-        of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
+	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
+	platform_device_register_simple("cpufreq-cpu0", -1, NULL, 0);
 }
 
 static const char *lager_boards_compat_dt[] __initdata = {
-- 
1.7.2.5

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