clocksource/drivers/cadence-ttc: Use ttc driver as platform driver

Currently TTC driver is TIMER_OF_DECLARE type driver. Because of
that, TTC driver may be initialized before other clock drivers. If
TTC driver is dependent on that clock driver then initialization of
TTC driver will failed.

So use TTC driver as platform driver instead of using
TIMER_OF_DECLARE.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1573122988-18399-1-git-send-email-rajan.vaja@xilinx.com

drivers/clocksource/timer-cadence-ttc.c

@@ -15,6 +15,8 @@
 #include <linux/of_irq.h>
 #include <linux/slab.h>
 #include <linux/sched_clock.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
 
 /*
  * This driver configures the 2 16/32-bit count-up timers as follows:
@@ -464,13 +466,7 @@ static int __init ttc_setup_clockevent(struct clk *clk,
 	return 0;
 }
 
-/**
- * ttc_timer_init - Initialize the timer
- *
- * Initializes the timer hardware and register the clock source and clock event
- * timers with Linux kernal timer framework
- */
-static int __init ttc_timer_init(struct device_node *timer)
+static int __init ttc_timer_probe(struct platform_device *pdev)
 {
 	unsigned int irq;
 	void __iomem *timer_baseaddr;
@@ -478,6 +474,7 @@ static int __init ttc_timer_init(struct device_node *timer)
 	static int initialized;
 	int clksel, ret;
 	u32 timer_width = 16;
+	struct device_node *timer = pdev->dev.of_node;
 
 	if (initialized)
 		return 0;
@@ -532,4 +529,17 @@ static int __init ttc_timer_init(struct device_node *timer)
 	return 0;
 }
 
-TIMER_OF_DECLARE(ttc, "cdns,ttc", ttc_timer_init);
+static const struct of_device_id ttc_timer_of_match[] = {
+	{.compatible = "cdns,ttc"},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, ttc_timer_of_match);
+
+static struct platform_driver ttc_timer_driver = {
+	.driver = {
+		.name	= "cdns_ttc_timer",
+		.of_match_table = ttc_timer_of_match,
+	},
+};
+builtin_platform_driver_probe(ttc_timer_driver, ttc_timer_probe);