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>

arch/arm/Kconfig

@@ -254,8 +254,8 @@ config ARCH_INTEGRATOR
 	bool "ARM Ltd. Integrator family"
 	select ARM_AMBA
 	select ARCH_HAS_CPUFREQ
-	select CLKDEV_LOOKUP
-	select HAVE_MACH_CLKDEV
+	select COMMON_CLK
+	select CLK_VERSATILE
 	select HAVE_TCM
 	select ICST
 	select GENERIC_CLOCKEVENTS
@@ -277,6 +277,7 @@ config ARCH_REALVIEW
 	select GENERIC_CLOCKEVENTS
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select PLAT_VERSATILE
+	select PLAT_VERSATILE_CLOCK
 	select PLAT_VERSATILE_CLCD
 	select ARM_TIMER_SP804
 	select GPIO_PL061 if GPIOLIB
@@ -295,6 +296,7 @@ config ARCH_VERSATILE
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select NEED_MACH_IO_H if PCI
 	select PLAT_VERSATILE
+	select PLAT_VERSATILE_CLOCK
 	select PLAT_VERSATILE_CLCD
 	select PLAT_VERSATILE_FPGA_IRQ
 	select ARM_TIMER_SP804
@@ -314,6 +316,7 @@ config ARCH_VEXPRESS
 	select ICST
 	select NO_IOPORT
 	select PLAT_VERSATILE
+	select PLAT_VERSATILE_CLOCK
 	select PLAT_VERSATILE_CLCD
 	help
 	  This enables support for the ARM Ltd Versatile Express boards.

arch/arm/mach-integrator/core.c

@@ -21,7 +21,6 @@
 #include <linux/amba/bus.h>
 #include <linux/amba/serial.h>
 #include <linux/io.h>
-#include <linux/clkdev.h>
 
 #include <mach/hardware.h>
 #include <mach/platform.h>
@@ -61,50 +60,6 @@ static struct amba_device *amba_devs[] __initdata = {
 	&kmi1_device,
 };
 
-/*
- * These are fixed clocks.
- */
-static struct clk clk24mhz = {
-	.rate	= 24000000,
-};
-
-static struct clk uartclk = {
-	.rate	= 14745600,
-};
-
-static struct clk dummy_apb_pclk;
-
-static struct clk_lookup lookups[] = {
-	{	/* Bus clock */
-		.con_id		= "apb_pclk",
-		.clk		= &dummy_apb_pclk,
-	}, {
-		/* Integrator/AP timer frequency */
-		.dev_id		= "ap_timer",
-		.clk		= &clk24mhz,
-	}, {	/* UART0 */
-		.dev_id		= "uart0",
-		.clk		= &uartclk,
-	}, {	/* UART1 */
-		.dev_id		= "uart1",
-		.clk		= &uartclk,
-	}, {	/* KMI0 */
-		.dev_id		= "kmi0",
-		.clk		= &clk24mhz,
-	}, {	/* KMI1 */
-		.dev_id		= "kmi1",
-		.clk		= &clk24mhz,
-	}, {	/* MMCI - IntegratorCP */
-		.dev_id		= "mmci",
-		.clk		= &uartclk,
-	}
-};
-
-void __init integrator_init_early(void)
-{
-	clkdev_add_table(lookups, ARRAY_SIZE(lookups));
-}
-
 static int __init integrator_init(void)
 {
 	int i;

arch/arm/mach-integrator/include/mach/clkdev.h

-#ifndef __ASM_MACH_CLKDEV_H
-#define __ASM_MACH_CLKDEV_H
-
-#include <linux/module.h>
-#include <plat/clock.h>
-
-struct clk {
-	unsigned long		rate;
-	const struct clk_ops	*ops;
-	struct module		*owner;
-	const struct icst_params *params;
-	void __iomem		*vcoreg;
-	void			*data;
-};
-
-static inline int __clk_get(struct clk *clk)
-{
-	return try_module_get(clk->owner);
-}
-
-static inline void __clk_put(struct clk *clk)
-{
-	module_put(clk->owner);
-}
-
-#endif

arch/arm/mach-integrator/integrator_ap.c

@@ -33,6 +33,7 @@
 #include <linux/io.h>
 #include <linux/mtd/physmap.h>
 #include <linux/clk.h>
+#include <linux/platform_data/clk-integrator.h>
 #include <video/vga.h>
 
 #include <mach/hardware.h>
@@ -174,6 +175,7 @@ static void __init ap_init_irq(void)
 
 	fpga_irq_init(VA_IC_BASE, "SC", IRQ_PIC_START,
 		-1, INTEGRATOR_SC_VALID_INT, NULL);
+	integrator_clk_init(false);
 }
 
 #ifdef CONFIG_PM
@@ -440,6 +442,10 @@ static void integrator_clockevent_init(unsigned long inrate)
 					0xffffU);
 }
 
+void __init ap_init_early(void)
+{
+}
+
 /*
  * Set up timer(s).
  */
@@ -471,7 +477,7 @@ MACHINE_START(INTEGRATOR, "ARM-Integrator")
 	.reserve	= integrator_reserve,
 	.map_io		= ap_map_io,
 	.nr_irqs	= NR_IRQS_INTEGRATOR_AP,
-	.init_early	= integrator_init_early,
+	.init_early	= ap_init_early,
 	.init_irq	= ap_init_irq,
 	.handle_irq	= fpga_handle_irq,
 	.timer		= &ap_timer,

arch/arm/mach-integrator/integrator_cp.c

@@ -21,8 +21,8 @@
 #include <linux/amba/mmci.h>
 #include <linux/io.h>
 #include <linux/gfp.h>
-#include <linux/clkdev.h>
 #include <linux/mtd/physmap.h>
+#include <linux/platform_data/clk-integrator.h>
 
 #include <mach/hardware.h>
 #include <mach/platform.h>
@@ -171,64 +171,9 @@ static void __init intcp_init_irq(void)
 
 	fpga_irq_init(INTCP_VA_SIC_BASE, "SIC", IRQ_SIC_START,
 		      IRQ_CP_CPPLDINT, sic_mask, NULL);
+	integrator_clk_init(true);
 }
 
-/*
- * Clock handling
- */
-#define CM_LOCK		(__io_address(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_LOCK_OFFSET)
-#define CM_AUXOSC	(__io_address(INTEGRATOR_HDR_BASE)+0x1c)
-
-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 void cp_auxvco_set(struct clk *clk, struct icst_vco vco)
-{
-	u32 val;
-
-	val = readl(clk->vcoreg) & ~0x7ffff;
-	val |= vco.v | (vco.r << 9) | (vco.s << 16);
-
-	writel(0xa05f, CM_LOCK);
-	writel(val, clk->vcoreg);
-	writel(0, CM_LOCK);
-}
-
-static const struct clk_ops cp_auxclk_ops = {
-	.round	= icst_clk_round,
-	.set	= icst_clk_set,
-	.setvco	= cp_auxvco_set,
-};
-
-static struct clk cp_auxclk = {
-	.ops	= &cp_auxclk_ops,
-	.params	= &cp_auxvco_params,
-	.vcoreg	= CM_AUXOSC,
-};
-
-static struct clk sp804_clk = {
-	.rate	= 1000000,
-};
-
-static struct clk_lookup cp_lookups[] = {
-	{	/* CLCD */
-		.dev_id		= "clcd",
-		.clk		= &cp_auxclk,
-	}, {	/* SP804 timers */
-		.dev_id		= "sp804",
-		.clk		= &sp804_clk,
-	},
-};
-
 /*
  * Flash handling.
  */
@@ -406,10 +351,6 @@ static struct amba_device *amba_devs[] __initdata = {
 
 static void __init intcp_init_early(void)
 {
-	clkdev_add_table(cp_lookups, ARRAY_SIZE(cp_lookups));
-
-	integrator_init_early();
-
 #ifdef CONFIG_PLAT_VERSATILE_SCHED_CLOCK
 	versatile_sched_clock_init(REFCOUNTER, 24000000);
 #endif

arch/arm/plat-versatile/Kconfig

 if PLAT_VERSATILE
 
+config PLAT_VERSATILE_CLOCK
+	bool
+
 config PLAT_VERSATILE_CLCD
 	bool
 

arch/arm/plat-versatile/Makefile

-obj-y	:= clock.o
+obj-$(CONFIG_PLAT_VERSATILE_CLOCK) += clock.o
 obj-$(CONFIG_PLAT_VERSATILE_CLCD) += clcd.o
 obj-$(CONFIG_PLAT_VERSATILE_FPGA_IRQ) += fpga-irq.o
 obj-$(CONFIG_PLAT_VERSATILE_LEDS) += leds.o

drivers/clk/versatile/Makefile

 # Makefile for Versatile-specific clocks
 obj-$(CONFIG_ICST)		+= clk-icst.o
+obj-$(CONFIG_ARCH_INTEGRATOR)	+= clk-integrator.o

drivers/clk/versatile/clk-integrator.c

+#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");
+}

include/linux/platform_data/clk-integrator.h

+void integrator_clk_init(bool is_cp);