This adds device tree support to the davinci timer so that when clocks
are moved to device tree, the timer will still work.

Signed-off-by: David Lechner <da...@lechnology.com>
---

v7 changes:
- add workaround for platform devices not available in early boot

v6 changes:
- none


 arch/arm/mach-davinci/Kconfig |  1 +
 arch/arm/mach-davinci/time.c  | 31 +++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/arch/arm/mach-davinci/Kconfig b/arch/arm/mach-davinci/Kconfig
index ba9912b..da8a039 100644
--- a/arch/arm/mach-davinci/Kconfig
+++ b/arch/arm/mach-davinci/Kconfig
@@ -59,6 +59,7 @@ config MACH_DA8XX_DT
        default y
        depends on ARCH_DAVINCI_DA850
        select PINCTRL
+       select TIMER_OF
        help
          Say y here to include support for TI DaVinci DA850 based using
          Flattened Device Tree. More information at Documentation/devicetree
diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
index d6a78f7..590b118 100644
--- a/arch/arm/mach-davinci/time.c
+++ b/arch/arm/mach-davinci/time.c
@@ -17,6 +17,7 @@
 #include <linux/io.h>
 #include <linux/clk.h>
 #include <linux/err.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/sched_clock.h>
 
@@ -405,3 +406,33 @@ void __init davinci_timer_init(struct clk *timer_clk)
        for (i=0; i< ARRAY_SIZE(timers); i++)
                timer32_config(&timers[i]);
 }
+
+static int __init of_davinci_timer_init(struct device_node *np)
+{
+       struct clk *clk;
+
+       clk = of_clk_get(np, 0);
+       if (IS_ERR(clk)) {
+               struct of_phandle_args clkspec;
+
+               /*
+                * Fall back to using ref_clk if the actual clock is not
+                * available. This currently always happens because platform
+                * clocks (i.e PLLs and PSCs) are registered as platform
+                * devices and therefore are not available at this point in
+                * the boot process.
+                */
+               clkspec.np = of_find_node_by_name(NULL, "ref_clk");
+               if (IS_ERR(clkspec.np)) {
+                       pr_err("%s: No clock available for timer!\n", __func__);
+                       return PTR_ERR(clkspec.np);
+               }
+               clk = of_clk_get_from_provider(&clkspec);
+               of_node_put(clkspec.np);
+       }
+
+       davinci_timer_init(clk);
+
+       return 0;
+}
+TIMER_OF_DECLARE(davinci_timer, "ti,davinci-timer", of_davinci_timer_init);
-- 
2.7.4

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