clk: mvebu: add Orion5x clock driver

This commit adds a core clock driver for the Orion5x SoC, with support
for the tclk, the CPU frequency and the DDR frequency. All the details
about the Sample-At-Reset register were extracted from the U-Boot
sources for Orion5x.

Note that Orion5x does not have gatable clocks, so this core clock
driver is sufficient to support clocking on Orion5x platforms.

Signed-off-by: Thomas Petazzoni <[e-mail]>
Acked-by: Sebastian Hesselbarth <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]
Cc: Mike Turquette <[e-mail]>
Signed-off-by: Jason Cooper <[e-mail]>

Documentation/devicetree/bindings/clock/mvebu-core-clock.txt

···
  2 = l2clk  (L2 Cache clock derived from CPU0 clock)
  3 = ddrclk (DDR controller clock derived from CPU0 clock)
 
+The following is a list of provided IDs and clock names on Orion5x:
+ 0 = tclk   (Internal Bus clock)
+ 1 = cpuclk (CPU0 clock)
+ 2 = ddrclk (DDR controller clock derived from CPU0 clock)
+
 Required properties:
 - compatible : shall be one of the following:
 	"marvell,armada-370-core-clock" - For Armada 370 SoC core clocks
···
 	"marvell,dove-core-clock" - for Dove SoC core clocks
 	"marvell,kirkwood-core-clock" - for Kirkwood SoC (except mv88f6180)
 	"marvell,mv88f6180-core-clock" - for Kirkwood MV88f6180 SoC
+	"marvell,mv88f5182-core-clock" - for Orion MV88F5182 SoC
+	"marvell,mv88f5281-core-clock" - for Orion MV88F5281 SoC
+	"marvell,mv88f6183-core-clock" - for Orion MV88F6183 SoC
 - reg : shall be the register address of the Sample-At-Reset (SAR) register
 - #clock-cells : from common clock binding; shall be set to 1
 

drivers/clk/mvebu/Kconfig

···
 config KIRKWOOD_CLK
 	bool
 	select MVEBU_CLK_COMMON
+
+config ORION_CLK
+	bool
+	select MVEBU_CLK_COMMON

drivers/clk/mvebu/Makefile

···
 obj-$(CONFIG_ARMADA_XP_CLK)	+= armada-xp.o
 obj-$(CONFIG_DOVE_CLK)		+= dove.o
 obj-$(CONFIG_KIRKWOOD_CLK)	+= kirkwood.o
+obj-$(CONFIG_ORION_CLK)		+= orion.o

drivers/clk/mvebu/orion.c

···
+/*
+ * Marvell Orion SoC clocks
+ *
+ * Copyright (C) 2014 Thomas Petazzoni
+ *
+ * Thomas Petazzoni <[e-mail]>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include "common.h"
+
+static const struct coreclk_ratio orion_coreclk_ratios[] __initconst = {
+	{ .id = 0, .name = "ddrclk", }
+};
+
+/*
+ * Orion 5182
+ */
+
+#define SAR_MV88F5182_TCLK_FREQ      8
+#define SAR_MV88F5182_TCLK_FREQ_MASK 0x3
+
+static u32 __init mv88f5182_get_tclk_freq(void __iomem *sar)
+{
+	u32 opt = (readl(sar) >> SAR_MV88F5182_TCLK_FREQ) &
+		SAR_MV88F5182_TCLK_FREQ_MASK;
+	if (opt == 1)
+		return 150000000;
+	else if (opt == 2)
+		return 166666667;
+	else
+		return 0;
+}
+
+#define SAR_MV88F5182_CPU_FREQ       4
+#define SAR_MV88F5182_CPU_FREQ_MASK  0xf
+
+static u32 __init mv88f5182_get_cpu_freq(void __iomem *sar)
+{
+	u32 opt = (readl(sar) >> SAR_MV88F5182_CPU_FREQ) &
+		SAR_MV88F5182_CPU_FREQ_MASK;
+	if (opt == 0)
+		return 333333333;
+	else if (opt == 1 || opt == 2)
+		return 400000000;
+	else if (opt == 3)
+		return 500000000;
+	else
+		return 0;
+}
+
+static void __init mv88f5182_get_clk_ratio(void __iomem *sar, int id,
+					   int *mult, int *div)
+{
+	u32 opt = (readl(sar) >> SAR_MV88F5182_CPU_FREQ) &
+		SAR_MV88F5182_CPU_FREQ_MASK;
+	if (opt == 0 || opt == 1) {
+		*mult = 1;
+		*div  = 2;
+	} else if (opt == 2 || opt == 3) {
+		*mult = 1;
+		*div  = 3;
+	} else {
+		*mult = 0;
+		*div  = 1;
+	}
+}
+
+static const struct coreclk_soc_desc mv88f5182_coreclks = {
+	.get_tclk_freq = mv88f5182_get_tclk_freq,
+	.get_cpu_freq = mv88f5182_get_cpu_freq,
+	.get_clk_ratio = mv88f5182_get_clk_ratio,
+	.ratios = orion_coreclk_ratios,
+	.num_ratios = ARRAY_SIZE(orion_coreclk_ratios),
+};
+
+static void __init mv88f5182_clk_init(struct device_node *np)
+{
+	return mvebu_coreclk_setup(np, &mv88f5182_coreclks);
+}
+
+CLK_OF_DECLARE(mv88f5182_clk, "marvell,mv88f5182-core-clock", mv88f5182_clk_init);
+
+/*
+ * Orion 5281
+ */
+
+static u32 __init mv88f5281_get_tclk_freq(void __iomem *sar)
+{
+	/* On 5281, tclk is always 166 Mhz */
+	return 166666667;
+}
+
+#define SAR_MV88F5281_CPU_FREQ       4
+#define SAR_MV88F5281_CPU_FREQ_MASK  0xf
+
+static u32 __init mv88f5281_get_cpu_freq(void __iomem *sar)
+{
+	u32 opt = (readl(sar) >> SAR_MV88F5281_CPU_FREQ) &
+		SAR_MV88F5281_CPU_FREQ_MASK;
+	if (opt == 1 || opt == 2)
+		return 400000000;
+	else if (opt == 3)
+		return 500000000;
+	else
+		return 0;
+}
+
+static void __init mv88f5281_get_clk_ratio(void __iomem *sar, int id,
+					   int *mult, int *div)
+{
+	u32 opt = (readl(sar) >> SAR_MV88F5281_CPU_FREQ) &
+		SAR_MV88F5281_CPU_FREQ_MASK;
+	if (opt == 1) {
+		*mult = 1;
+		*div = 2;
+	} else if (opt == 2 || opt == 3) {
+		*mult = 1;
+		*div = 3;
+	} else {
+		*mult = 0;
+		*div = 1;
+	}
+}
+
+static const struct coreclk_soc_desc mv88f5281_coreclks = {
+	.get_tclk_freq = mv88f5281_get_tclk_freq,
+	.get_cpu_freq = mv88f5281_get_cpu_freq,
+	.get_clk_ratio = mv88f5281_get_clk_ratio,
+	.ratios = orion_coreclk_ratios,
+	.num_ratios = ARRAY_SIZE(orion_coreclk_ratios),
+};
+
+static void __init mv88f5281_clk_init(struct device_node *np)
+{
+	return mvebu_coreclk_setup(np, &mv88f5281_coreclks);
+}
+
+CLK_OF_DECLARE(mv88f5281_clk, "marvell,mv88f5281-core-clock", mv88f5281_clk_init);
+
+/*
+ * Orion 6183
+ */
+
+#define SAR_MV88F6183_TCLK_FREQ      9
+#define SAR_MV88F6183_TCLK_FREQ_MASK 0x1
+
+static u32 __init mv88f6183_get_tclk_freq(void __iomem *sar)
+{
+	u32 opt = (readl(sar) >> SAR_MV88F6183_TCLK_FREQ) &
+		SAR_MV88F6183_TCLK_FREQ_MASK;
+	if (opt == 0)
+		return 133333333;
+	else if (opt == 1)
+		return 166666667;
+	else
+		return 0;
+}
+
+#define SAR_MV88F6183_CPU_FREQ       1
+#define SAR_MV88F6183_CPU_FREQ_MASK  0x3f
+
+static u32 __init mv88f6183_get_cpu_freq(void __iomem *sar)
+{
+	u32 opt = (readl(sar) >> SAR_MV88F6183_CPU_FREQ) &
+		SAR_MV88F6183_CPU_FREQ_MASK;
+	if (opt == 9)
+		return 333333333;
+	else if (opt == 17)
+		return 400000000;
+	else
+		return 0;
+}
+
+static void __init mv88f6183_get_clk_ratio(void __iomem *sar, int id,
+					   int *mult, int *div)
+{
+	u32 opt = (readl(sar) >> SAR_MV88F6183_CPU_FREQ) &
+		SAR_MV88F6183_CPU_FREQ_MASK;
+	if (opt == 9 || opt == 17) {
+		*mult = 1;
+		*div  = 2;
+	} else {
+		*mult = 0;
+		*div  = 1;
+	}
+}
+
+static const struct coreclk_soc_desc mv88f6183_coreclks = {
+	.get_tclk_freq = mv88f6183_get_tclk_freq,
+	.get_cpu_freq = mv88f6183_get_cpu_freq,
+	.get_clk_ratio = mv88f6183_get_clk_ratio,
+	.ratios = orion_coreclk_ratios,
+	.num_ratios = ARRAY_SIZE(orion_coreclk_ratios),
+};
+
+
+static void __init mv88f6183_clk_init(struct device_node *np)
+{
+	return mvebu_coreclk_setup(np, &mv88f6183_coreclks);
+}
+
+CLK_OF_DECLARE(mv88f6183_clk, "marvell,mv88f6183-core-clock", mv88f6183_clk_init);