[PATCH v9 25/27] ARM: davinci: add device tree support to timer

David Lechner
2018-04-27T00:17:43Z

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 <david@lechnology.com>
---

v9 changes:
- none (there were supposed to be changed, but apparently they got squashed
into the next commit - will fix on the next round)

v8 changes:
- none

v7 changes:
- rebased
- add davinci prefix to commit message

v6 changes:
- rebased

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 ba9912b4dfab..da8a039d65f9 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 7ea3db0ff062..7a8c6fada644 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>

@@ -397,3 +398,33 @@ 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);
--
2.17.0