clk: convert ARM RealView to common clk

This converts the ARM RealView machine over to using the common
clock. The approach is similar to the one used for the Integrator,
and we're reusing the ICST wrapper code.

We have to put the clock intialization in the timer init function
for the clocks to be available when initializing the timer,
keeping them in early_init() is too early for the common clk.

Since we now have to go down and compile drivers/clk/versatile
a CONFIG_COMMON_CLK_VERSATILE symbol has been added so the proper
code gets compiled into the kernel for either machine. A leftover
CLK_VERSATILE in the Integrator Kconfig was fixed up to use
the new symbol as well.

Tested on ARM RealView PB1176.

Cc: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

2 files changed, 115 insertions, 0 deletions

diff --git a/drivers/clk/versatile/Makefile b/drivers/clk/versatile/Makefile
index 50cf6a2ee693..c0a0f6478798 100644
--- a/drivers/clk/versatile/Makefile
+++ b/drivers/clk/versatile/Makefile
@@ -1,3 +1,4 @@
 # Makefile for Versatile-specific clocks
 obj-$(CONFIG_ICST)		+= clk-icst.o
 obj-$(CONFIG_ARCH_INTEGRATOR)	+= clk-integrator.o
+obj-$(CONFIG_ARCH_REALVIEW)	+= clk-realview.o
diff --git a/drivers/clk/versatile/clk-realview.c b/drivers/clk/versatile/clk-realview.c
new file mode 100644
index 000000000000..e21a99cef378
--- /dev/null
+++ b/drivers/clk/versatile/clk-realview.c
@@ -0,0 +1,114 @@
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/clk-provider.h>
+
+#include <mach/hardware.h>
+#include <mach/platform.h>
+
+#include "clk-icst.h"
+
+/*
+ * Implementation of the ARM RealView clock trees.
+ */
+
+static void __iomem *sys_lock;
+static void __iomem *sys_vcoreg;
+
+/**
+ * realview_oscvco_get() - get ICST OSC settings for the RealView
+ */
+static struct icst_vco realview_oscvco_get(void)
+{
+	u32 val;
+	struct icst_vco vco;
+
+	val = readl(sys_vcoreg);
+	vco.v = val & 0x1ff;
+	vco.r = (val >> 9) & 0x7f;
+	vco.s = (val >> 16) & 03;
+	return vco;
+}
+
+static void realview_oscvco_set(struct icst_vco vco)
+{
+	u32 val;
+
+	val = readl(sys_vcoreg) & ~0x7ffff;
+	val |= vco.v | (vco.r << 9) | (vco.s << 16);
+
+	/* This magic unlocks the CM VCO so it can be controlled */
+	writel(0xa05f, sys_lock);
+	writel(val, sys_vcoreg);
+	/* This locks the CM again */
+	writel(0, sys_lock);
+}
+
+static const struct icst_params realview_oscvco_params = {
+	.ref		= 24000000,
+	.vco_max	= ICST307_VCO_MAX,
+	.vco_min	= ICST307_VCO_MIN,
+	.vd_min		= 4 + 8,
+	.vd_max		= 511 + 8,
+	.rd_min		= 1 + 2,
+	.rd_max		= 127 + 2,
+	.s2div		= icst307_s2div,
+	.idx2s		= icst307_idx2s,
+};
+
+static const struct clk_icst_desc __initdata realview_icst_desc = {
+	.params = &realview_oscvco_params,
+	.getvco = realview_oscvco_get,
+	.setvco = realview_oscvco_set,
+};
+
+/*
+ * realview_clk_init() - set up the RealView clock tree
+ */
+void __init realview_clk_init(void __iomem *sysbase, bool is_pb1176)
+{
+	struct clk *clk;
+
+	sys_lock = sysbase + REALVIEW_SYS_LOCK_OFFSET;
+	if (is_pb1176)
+		sys_vcoreg = sysbase + REALVIEW_SYS_OSC0_OFFSET;
+	else
+		sys_vcoreg = sysbase + REALVIEW_SYS_OSC4_OFFSET;
+
+
+	/* APB clock dummy */
+	clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, CLK_IS_ROOT, 0);
+	clk_register_clkdev(clk, "apb_pclk", NULL);
+
+	/* 24 MHz clock */
+	clk = clk_register_fixed_rate(NULL, "clk24mhz", NULL, CLK_IS_ROOT,
+				24000000);
+	clk_register_clkdev(clk, NULL, "dev:uart0");
+	clk_register_clkdev(clk, NULL, "dev:uart1");
+	clk_register_clkdev(clk, NULL, "dev:uart2");
+	clk_register_clkdev(clk, NULL, "fpga:kmi0");
+	clk_register_clkdev(clk, NULL, "fpga:kmi1");
+	clk_register_clkdev(clk, NULL, "fpga:mmc0");
+	clk_register_clkdev(clk, NULL, "dev:ssp0");
+	if (is_pb1176) {
+		/*
+		 * UART3 is on the dev chip in PB1176
+		 * UART4 only exists in PB1176
+		 */
+		clk_register_clkdev(clk, NULL, "dev:uart3");
+		clk_register_clkdev(clk, NULL, "dev:uart4");
+	} else
+		clk_register_clkdev(clk, NULL, "fpga:uart3");
+
+
+	/* 1 MHz clock */
+	clk = clk_register_fixed_rate(NULL, "clk1mhz", NULL, CLK_IS_ROOT,
+				      1000000);
+	clk_register_clkdev(clk, NULL, "sp804");
+
+	/* ICST VCO clock */
+	clk = icst_clk_register(NULL, &realview_icst_desc);
+	clk_register_clkdev(clk, NULL, "dev:clcd");
+	clk_register_clkdev(clk, NULL, "issp:clcd");
+}