ARM: integrator: convert to common clock

This converts the Integrator platform to use common clock
and the ICST driver. Since from this point not all ARM
reference platforms use the clock, we define
CONFIG_PLAT_VERSATILE_CLOCK and select it for all platforms
except the Integrator.

Open issue: I could not use the .init_early() field of the
machine descriptor to initialize the clocks, but had to
move them to .init_irq(), so presumably .init_early() is
so early that common clock is not up, and .init_machine()
is too late since it's needed for the clockevent/clocksource
initialization. Any suggestions on how to solve this is
very welcome.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[mturquette@linaro.org: use 'select' instead of versatile Kconfig]
Signed-off-by: Mike Turquette <mturquette@linaro.org>

2 files changed, 112 insertions, 0 deletions

diff --git a/drivers/clk/versatile/Makefile b/drivers/clk/versatile/Makefile
index a83539b41787..50cf6a2ee693 100644
--- a/drivers/clk/versatile/Makefile
+++ b/drivers/clk/versatile/Makefile
@@ -1,2 +1,3 @@
 # Makefile for Versatile-specific clocks
 obj-$(CONFIG_ICST)		+= clk-icst.o
+obj-$(CONFIG_ARCH_INTEGRATOR)	+= clk-integrator.o
diff --git a/drivers/clk/versatile/clk-integrator.c b/drivers/clk/versatile/clk-integrator.c
new file mode 100644
index 000000000000..a5053921bf7f
--- /dev/null
+++ b/drivers/clk/versatile/clk-integrator.c
@@ -0,0 +1,111 @@
+#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 Integrator/AP and Integrator/CP clock tree.
+ * Inspired by portions of:
+ * plat-versatile/clock.c and plat-versatile/include/plat/clock.h
+ */
+#define CM_LOCK		(__io_address(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_LOCK_OFFSET)
+#define CM_AUXOSC	(__io_address(INTEGRATOR_HDR_BASE)+0x1c)
+
+/**
+ * cp_auxvco_get() - get ICST VCO settings for the Integrator/CP
+ * @vco: ICST VCO parameters to update with hardware status
+ */
+static struct icst_vco cp_auxvco_get(void)
+{
+	u32 val;
+	struct icst_vco vco;
+
+	val = readl(CM_AUXOSC);
+	vco.v = val & 0x1ff;
+	vco.r = (val >> 9) & 0x7f;
+	vco.s = (val >> 16) & 03;
+	return vco;
+}
+
+/**
+ * cp_auxvco_set() - commit changes to Integrator/CP ICST VCO
+ * @vco: ICST VCO parameters to commit
+ */
+static void cp_auxvco_set(struct icst_vco vco)
+{
+	u32 val;
+
+	val = readl(CM_AUXOSC) & ~0x7ffff;
+	val |= vco.v | (vco.r << 9) | (vco.s << 16);
+
+	/* This magic unlocks the CM VCO so it can be controlled */
+	writel(0xa05f, CM_LOCK);
+	writel(val, CM_AUXOSC);
+	/* This locks the CM again */
+	writel(0, CM_LOCK);
+}
+
+static const struct icst_params cp_auxvco_params = {
+	.ref		= 24000000,
+	.vco_max	= ICST525_VCO_MAX_5V,
+	.vco_min	= ICST525_VCO_MIN,
+	.vd_min 	= 8,
+	.vd_max 	= 263,
+	.rd_min 	= 3,
+	.rd_max 	= 65,
+	.s2div		= icst525_s2div,
+	.idx2s		= icst525_idx2s,
+};
+
+static const struct clk_icst_desc __initdata cp_icst_desc = {
+	.params = &cp_auxvco_params,
+	.getvco = cp_auxvco_get,
+	.setvco = cp_auxvco_set,
+};
+
+/*
+ * integrator_clk_init() - set up the integrator clock tree
+ * @is_cp: pass true if it's the Integrator/CP else AP is assumed
+ */
+void __init integrator_clk_init(bool is_cp)
+{
+	struct clk *clk;
+
+	/* APB clock dummy */
+	clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, CLK_IS_ROOT, 0);
+	clk_register_clkdev(clk, "apb_pclk", NULL);
+
+	/* UART reference clock */
+	clk = clk_register_fixed_rate(NULL, "uartclk", NULL, CLK_IS_ROOT,
+				14745600);
+	clk_register_clkdev(clk, NULL, "uart0");
+	clk_register_clkdev(clk, NULL, "uart1");
+	if (is_cp)
+		clk_register_clkdev(clk, NULL, "mmci");
+
+	/* 24 MHz clock */
+	clk = clk_register_fixed_rate(NULL, "clk24mhz", NULL, CLK_IS_ROOT,
+				24000000);
+	clk_register_clkdev(clk, NULL, "kmi0");
+	clk_register_clkdev(clk, NULL, "kmi1");
+	if (!is_cp)
+		clk_register_clkdev(clk, NULL, "ap_timer");
+
+	if (!is_cp)
+		return;
+
+	/* 1 MHz clock */
+	clk = clk_register_fixed_rate(NULL, "clk1mhz", NULL, CLK_IS_ROOT,
+				1000000);
+	clk_register_clkdev(clk, NULL, "sp804");
+
+	/* ICST VCO clock used on the Integrator/CP CLCD */
+	clk = icst_clk_register(NULL, &cp_icst_desc);
+	clk_register_clkdev(clk, NULL, "clcd");
+}