ARM: at91: PIT: Rework probe functions

The PIT timer driver until now had a single probe function, disregarding wether
it was probed through DT or in the old-style way. This code later on was
calling some DT function to retrieve the proper values for its base address,
interrupts and clocks.

While this was working, it was preventing the usage of CLOCKSOURCE_OF_DECLARE,
and the two different probe path were not as clearly separated as they could
be.

Rework the probe path to take this into account, and switch to
CLOCKSOURCE_OF_DECLARE.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

4 files changed, 51 insertions, 64 deletions

diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 6eb3c658761d..c3f9ebc5f9f5 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -34,6 +34,7 @@ config OLD_IRQ_AT91
         select SPARSE_IRQ
 
 config AT91_SAM9_TIME
+        select CLKSRC_OF if OF
         bool
 
 config HAVE_AT91_SMD
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c
index b87a12f05540..af466eb68624 100644
--- a/arch/arm/mach-at91/at91sam926x_time.c
+++ b/arch/arm/mach-at91/at91sam926x_time.c
@@ -19,7 +19,6 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 
-#include <asm/mach/time.h>
 #include <mach/hardware.h>
 
 #define AT91_PIT_MR             0x00                    /* Mode Register */
@@ -176,81 +175,21 @@ static struct irqaction at91sam926x_pit_irq = {
         .name           = "at91_tick",
         .flags          = IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
         .handler        = at91sam926x_pit_interrupt,
-        .irq            = NR_IRQS_LEGACY + AT91_ID_SYS,
 };
 
-#ifdef CONFIG_OF
-static struct of_device_id pit_timer_ids[] = {
-        { .compatible = "atmel,at91sam9260-pit" },
-        { /* sentinel */ }
-};
-
-static int __init of_at91sam926x_pit_init(void)
-{
-        struct device_node      *np;
-        int                     ret;
-
-        np = of_find_matching_node(NULL, pit_timer_ids);
-        if (!np)
-                goto err;
-
-        pit_base_addr = of_iomap(np, 0);
-        if (!pit_base_addr)
-                goto node_err;
-
-        mck = of_clk_get(np, 0);
-
-        /* Get the interrupts property */
-        ret = irq_of_parse_and_map(np, 0);
-        if (!ret) {
-                pr_crit("AT91: PIT: Unable to get IRQ from DT\n");
-                if (!IS_ERR(mck))
-                        clk_put(mck);
-                goto ioremap_err;
-        }
-        at91sam926x_pit_irq.irq = ret;
-
-        of_node_put(np);
-
-        return 0;
-
-ioremap_err:
-        iounmap(pit_base_addr);
-node_err:
-        of_node_put(np);
-err:
-        return -EINVAL;
-}
-#else
-static int __init of_at91sam926x_pit_init(void)
-{
-        return -EINVAL;
-}
-#endif
-
 /*
  * Set up both clocksource and clockevent support.
  */
-void __init at91sam926x_pit_init(void)
+static void __init at91sam926x_pit_common_init(void)
 {
         unsigned long   pit_rate;
         unsigned        bits;
         int             ret;
 
-        mck = ERR_PTR(-ENOENT);
-
-        /* For device tree enabled device: initialize here */
-        of_at91sam926x_pit_init();
-
         /*
          * Use our actual MCK to figure out how many MCK/16 ticks per
          * 1/HZ period (instead of a compile-time constant LATCH).
          */
-        if (IS_ERR(mck))
-                mck = clk_get(NULL, "mck");
-
-        if (IS_ERR(mck))
-                panic("AT91: PIT: Unable to get mck clk\n");
         pit_rate = clk_get_rate(mck) / 16;
         pit_cycle = DIV_ROUND_CLOSEST(pit_rate, HZ);
         WARN_ON(((pit_cycle - 1) & ~AT91_PIT_PIV) != 0);
@@ -277,6 +216,51 @@ void __init at91sam926x_pit_init(void)
         clockevents_register_device(&pit_clkevt);
 }
 
+static void __init at91sam926x_pit_dt_init(struct device_node *node)
+{
+        unsigned int irq;
+
+        pit_base_addr = of_iomap(node, 0);
+        if (!pit_base_addr)
+                return;
+
+        mck = of_clk_get(node, 0);
+        if (IS_ERR(mck))
+                /* Fallback on clkdev for !CCF-based boards */
+                mck = clk_get(NULL, "mck");
+
+        if (IS_ERR(mck))
+                panic("AT91: PIT: Unable to get mck clk\n");
+
+        /* Get the interrupts property */
+        irq = irq_of_parse_and_map(node, 0);
+        if (!irq) {
+                pr_crit("AT91: PIT: Unable to get IRQ from DT\n");
+                goto clk_err;
+        }
+
+        at91sam926x_pit_irq.irq = irq;
+
+        at91sam926x_pit_common_init();
+
+clk_err:
+        clk_put(mck);
+        iounmap(pit_base_addr);
+}
+CLOCKSOURCE_OF_DECLARE(at91sam926x_pit, "atmel,at91sam9260-pit",
+                       at91sam926x_pit_dt_init);
+
+void __init at91sam926x_pit_init(void)
+{
+        mck = clk_get(NULL, "mck");
+        if (IS_ERR(mck))
+                panic("AT91: PIT: Unable to get mck clk\n");
+
+        at91sam926x_pit_irq.irq = NR_IRQS_LEGACY + AT91_ID_SYS;
+
+        at91sam926x_pit_common_init();
+}
+
 void __init at91sam926x_ioremap_pit(u32 addr)
 {
         if (of_have_populated_dt())
diff --git a/arch/arm/mach-at91/board-dt-sam9.c b/arch/arm/mach-at91/board-dt-sam9.c
index dfa8d48146fe..78962fd23859 100644
--- a/arch/arm/mach-at91/board-dt-sam9.c
+++ b/arch/arm/mach-at91/board-dt-sam9.c
@@ -14,6 +14,7 @@
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/clk-provider.h>
+#include <linux/clocksource.h>
 
 #include <asm/setup.h>
 #include <asm/irq.h>
@@ -31,7 +32,7 @@ static void __init sam9_dt_timer_init(void)
 #if defined(CONFIG_COMMON_CLK)
         of_clk_init(NULL);
 #endif
-        at91sam926x_pit_init();
+        clocksource_of_init();
 }
 
 static const char *at91_dt_board_compat[] __initdata = {
diff --git a/arch/arm/mach-at91/board-dt-sama5.c b/arch/arm/mach-at91/board-dt-sama5.c
index d6fe04bcaabd..4f01e34fae0a 100644
--- a/arch/arm/mach-at91/board-dt-sama5.c
+++ b/arch/arm/mach-at91/board-dt-sama5.c
@@ -17,6 +17,7 @@
 #include <linux/of_platform.h>
 #include <linux/phy.h>
 #include <linux/clk-provider.h>
+#include <linux/clocksource.h>
 
 #include <asm/setup.h>
 #include <asm/irq.h>
@@ -32,7 +33,7 @@ static void __init sama5_dt_timer_init(void)
 #if defined(CONFIG_COMMON_CLK)
         of_clk_init(NULL);
 #endif
-        at91sam926x_pit_init();
+        clocksource_of_init();
 }
 
 static int ksz9021rn_phy_fixup(struct phy_device *phy)