ARM: tegra: split tegra_pmc_init() in two

Tegra's board file currently initializes clocks much earlier than those
for most other ARM SoCs. The reason is:

* The PMC HW block is involved in the path of some interrupts (i.e. it
inverts, or not, the IRQ input pin dedicated to the PMIC).

* So, that part of the PMC must be initialized early so that the IRQ
polarity is correct.

* The PMC initialization is currently monolithic, and the PMC has some
clock inputs, so the init routine ends up calling of_clk_get_by_name(),
and hence clocks must be set up early too.

In order to defer clock initialization to the more typical location,
split out the portions of tegra_pmc_init() that are truly IRQ-related
into a separate tegra_pmc_init_irq(), which can be called from the
machine descriptor's .init_irq() function, and defer the rest until
the machine descriptor's .init_machine() function. This allows the
clock initiliazation to happen from the machine descriptor's
.init_time() function, as is typical.

Signed-off-by: Stephen Warren <swarren@nvidia.com>

arch/arm/mach-tegra/common.c

@@ -24,7 +24,6 @@
 #include <linux/delay.h>
 #include <linux/reboot.h>
 #include <linux/irqchip.h>
-#include <linux/clk-provider.h>
 
 #include <asm/hardware/cache-l2x0.h>
 
@@ -61,8 +60,7 @@ u32 tegra_uart_config[4] = {
 #ifdef CONFIG_OF
 void __init tegra_dt_init_irq(void)
 {
-	of_clk_init(NULL);
-	tegra_pmc_init();
+	tegra_pmc_init_irq();
 	tegra_init_irq();
 	irqchip_init();
 	tegra_legacy_irq_syscore_init();

arch/arm/mach-tegra/pmc.c

@@ -285,7 +285,28 @@ static const struct of_device_id matches[] __initconst = {
 	{ }
 };
 
-static void __init tegra_pmc_parse_dt(void)
+void __init tegra_pmc_init_irq(void)
+{
+	struct device_node *np;
+	u32 val;
+
+	np = of_find_matching_node(NULL, matches);
+	BUG_ON(!np);
+
+	tegra_pmc_base = of_iomap(np, 0);
+
+	tegra_pmc_invert_interrupt = of_property_read_bool(np,
+				     "nvidia,invert-interrupt");
+
+	val = tegra_pmc_readl(PMC_CTRL);
+	if (tegra_pmc_invert_interrupt)
+		val |= PMC_CTRL_INTR_LOW;
+	else
+		val &= ~PMC_CTRL_INTR_LOW;
+	tegra_pmc_writel(val, PMC_CTRL);
+}
+
+void __init tegra_pmc_init(void)
 {
 	struct device_node *np;
 	u32 prop;
@@ -296,10 +317,6 @@ static void __init tegra_pmc_parse_dt(void)
 	np = of_find_matching_node(NULL, matches);
 	BUG_ON(!np);
 
-	tegra_pmc_base = of_iomap(np, 0);
-
-	tegra_pmc_invert_interrupt = of_property_read_bool(np,
-				     "nvidia,invert-interrupt");
 	tegra_pclk = of_clk_get_by_name(np, "pclk");
 	WARN_ON(IS_ERR(tegra_pclk));
 
@@ -365,17 +382,3 @@ static void __init tegra_pmc_parse_dt(void)
 
 	pmc_pm_data.suspend_mode = suspend_mode;
 }
-
-void __init tegra_pmc_init(void)
-{
-	u32 val;
-
-	tegra_pmc_parse_dt();
-
-	val = tegra_pmc_readl(PMC_CTRL);
-	if (tegra_pmc_invert_interrupt)
-		val |= PMC_CTRL_INTR_LOW;
-	else
-		val &= ~PMC_CTRL_INTR_LOW;
-	tegra_pmc_writel(val, PMC_CTRL);
-}

arch/arm/mach-tegra/pmc.h

@@ -39,6 +39,7 @@ bool tegra_pmc_cpu_is_powered(int cpuid);
 int tegra_pmc_cpu_power_on(int cpuid);
 int tegra_pmc_cpu_remove_clamping(int cpuid);
 
+void tegra_pmc_init_irq(void);
 void tegra_pmc_init(void);
 
 #endif

arch/arm/mach-tegra/tegra.c

@@ -33,6 +33,7 @@
 #include <linux/slab.h>
 #include <linux/sys_soc.h>
 #include <linux/usb/tegra_usb_phy.h>
+#include <linux/clk-provider.h>
 #include <linux/clk/tegra.h>
 
 #include <asm/mach-types.h>
@@ -44,6 +45,7 @@
 #include "common.h"
 #include "fuse.h"
 #include "iomap.h"
+#include "pmc.h"
 
 static void __init tegra_dt_init(void)
 {
@@ -51,6 +53,8 @@ static void __init tegra_dt_init(void)
 	struct soc_device *soc_dev;
 	struct device *parent = NULL;
 
+	tegra_pmc_init();
+
 	tegra_clocks_apply_init_table();
 
 	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
@@ -80,6 +84,12 @@ out:
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, parent);
 }
 
+static void __init tegra_dt_init_time(void)
+{
+	of_clk_init(NULL);
+	clocksource_of_init();
+}
+
 static void __init paz00_init(void)
 {
 	if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
@@ -119,7 +129,7 @@ DT_MACHINE_START(TEGRA_DT, "NVIDIA Tegra SoC (Flattened Device Tree)")
 	.smp		= smp_ops(tegra_smp_ops),
 	.init_early	= tegra_init_early,
 	.init_irq	= tegra_dt_init_irq,
-	.init_time	= clocksource_of_init,
+	.init_time	= tegra_dt_init_time,
 	.init_machine	= tegra_dt_init,
 	.init_late	= tegra_dt_init_late,
 	.restart	= tegra_assert_system_reset,