ARM: integrator: switch to fetch clocks from device tree

This atomic commit changes the Integrator clock implementation
and the machines to register clocks from the device tree and
use these instead of the previous hard-coded clocks.

In the clock implementation all hard-coded clocks and the
special initialization function call goes away, and is
replaced by two compatible strings for the two clocks
available on the core module.

Cc: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/clock/arm-integrator.txt

@@ -0,0 +1,34 @@
+Clock bindings for ARM Integrator Core Module clocks
+
+Auxilary Oscillator Clock
+
+This is a configurable clock fed from a 24 MHz chrystal,
+used for generating e.g. video clocks. It is located on the
+core module and there is only one of these.
+
+This clock node *must* be a subnode of the core module, since
+it obtains the base address for it's address range from its
+parent node.
+
+
+Required properties:
+- compatible: must be "arm,integrator-cm-auxosc"
+- #clock-cells: must be <0>
+
+Optional properties:
+- clocks: parent clock(s)
+
+Example:
+
+core-module@10000000 {
+	xtal24mhz: xtal24mhz@24M {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <24000000>;
+	};
+	auxosc: cm_aux_osc@25M {
+		#clock-cells = <0>;
+		compatible = "arm,integrator-cm-auxosc";
+		clocks = <&xtal24mhz>;
+	};
+};

arch/arm/mach-integrator/integrator_ap.c

@@ -42,6 +42,7 @@
 #include <linux/sys_soc.h>
 #include <linux/termios.h>
 #include <linux/sched_clock.h>
+#include <linux/clk-provider.h>
 
 #include <mach/hardware.h>
 #include <mach/platform.h>
@@ -402,10 +403,7 @@ static void __init ap_of_timer_init(void)
 	struct clk *clk;
 	unsigned long rate;
 
-	clk = clk_get_sys("ap_timer", NULL);
-	BUG_ON(IS_ERR(clk));
-	clk_prepare_enable(clk);
-	rate = clk_get_rate(clk);
+	of_clk_init(NULL);
 
 	err = of_property_read_string(of_aliases,
 				"arm,timer-primary", &path);
@@ -415,6 +413,12 @@ static void __init ap_of_timer_init(void)
 	base = of_iomap(node, 0);
 	if (WARN_ON(!base))
 		return;
+
+	clk = of_clk_get(node, 0);
+	BUG_ON(IS_ERR(clk));
+	clk_prepare_enable(clk);
+	rate = clk_get_rate(clk);
+
 	writel(0, base + TIMER_CTRL);
 	integrator_clocksource_init(rate, base);
 
@@ -427,6 +431,12 @@ static void __init ap_of_timer_init(void)
 	if (WARN_ON(!base))
 		return;
 	irq = irq_of_parse_and_map(node, 0);
+
+	clk = of_clk_get(node, 0);
+	BUG_ON(IS_ERR(clk));
+	clk_prepare_enable(clk);
+	rate = clk_get_rate(clk);
+
 	writel(0, base + TIMER_CTRL);
 	integrator_clockevent_init(rate, base, irq);
 }
@@ -440,7 +450,6 @@ static void __init ap_init_irq_of(void)
 {
 	cm_init();
 	of_irq_init(fpga_irq_of_match);
-	integrator_clk_init(false);
 }
 
 /* For the Device Tree, add in the UART callbacks as AUXDATA */

arch/arm/mach-integrator/integrator_cp.c

@@ -23,7 +23,6 @@
 #include <linux/irqchip/versatile-fpga.h>
 #include <linux/gfp.h>
 #include <linux/mtd/physmap.h>
-#include <linux/platform_data/clk-integrator.h>
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
 #include <linux/of_platform.h>
@@ -33,8 +32,6 @@
 #include <mach/platform.h>
 #include <asm/setup.h>
 #include <asm/mach-types.h>
-#include <asm/hardware/arm_timer.h>
-#include <asm/hardware/icst.h>
 
 #include <mach/lm.h>
 
@@ -43,8 +40,6 @@
 #include <asm/mach/map.h>
 #include <asm/mach/time.h>
 
-#include <asm/hardware/timer-sp.h>
-
 #include <plat/clcd.h>
 #include <plat/sched_clock.h>
 
@@ -250,7 +245,6 @@ static void __init intcp_init_irq_of(void)
 {
 	cm_init();
 	of_irq_init(fpga_irq_of_match);
-	integrator_clk_init(true);
 }
 
 /*

drivers/clk/versatile/clk-integrator.c

@@ -10,20 +10,17 @@
 #include <linux/clk.h>
 #include <linux/clkdev.h>
 #include <linux/err.h>
-#include <linux/platform_data/clk-integrator.h>
-
-#include <mach/hardware.h>
-#include <mach/platform.h>
+#include <linux/of.h>
+#include <linux/of_address.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 INTEGRATOR_HDR_LOCK_OFFSET	0x14
 
-static const struct icst_params cp_auxvco_params = {
+/* Base offset for the core module */
+static void __iomem *cm_base;
+
+static const struct icst_params cp_auxosc_params = {
 	.ref		= 24000000,
 	.vco_max	= ICST525_VCO_MAX_5V,
 	.vco_min	= ICST525_VCO_MIN,
@@ -35,50 +32,37 @@ static const struct icst_params cp_auxvco_params = {
 	.idx2s		= icst525_idx2s,
 };
 
-static const struct clk_icst_desc __initdata cp_icst_desc = {
-	.params = &cp_auxvco_params,
+static const struct clk_icst_desc __initdata cm_auxosc_desc = {
+	.params = &cp_auxosc_params,
 	.vco_offset = 0x1c,
 	.lock_offset = INTEGRATOR_HDR_LOCK_OFFSET,
 };
 
-/*
- * 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)
+static void __init of_integrator_cm_osc_setup(struct device_node *np)
 {
-	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");
+	struct clk *clk = ERR_PTR(-EINVAL);
+	const char *clk_name = np->name;
+	const struct clk_icst_desc *desc = &cm_auxosc_desc;
 
-	if (!is_cp)
-		return;
+	if (!cm_base) {
+		/* Remap the core module base if not done yet */
+		struct device_node *parent;
 
-	/* 1 MHz clock */
-	clk = clk_register_fixed_rate(NULL, "clk1mhz", NULL, CLK_IS_ROOT,
-				1000000);
-	clk_register_clkdev(clk, NULL, "sp804");
+		parent = of_get_parent(np);
+		if (!np) {
+			pr_err("no parent on core module clock\n");
+			return;
+		}
+		cm_base = of_iomap(parent, 0);
+		if (!cm_base) {
+			pr_err("could not remap core module base\n");
+			return;
+		}
+	}
 
-	/* ICST VCO clock used on the Integrator/CP CLCD */
-	clk = icst_clk_register(NULL, &cp_icst_desc, "icst",
-				__io_address(INTEGRATOR_HDR_BASE));
-	clk_register_clkdev(clk, NULL, "clcd");
+	clk = icst_clk_register(NULL, desc, clk_name, cm_base);
+	if (!IS_ERR(clk))
+		of_clk_add_provider(np, of_clk_src_simple_get, clk);
 }
+CLK_OF_DECLARE(integrator_cm_auxosc_clk,
+	"arm,integrator-cm-auxosc", of_integrator_cm_osc_setup);

include/linux/platform_data/clk-integrator.h

@@ -1,3 +1,2 @@
-void integrator_clk_init(bool is_cp);
 void integrator_impd1_clk_init(void __iomem *base, unsigned int id);
 void integrator_impd1_clk_exit(unsigned int id);