clocksource/drivers/ralink: Add Ralink System Tick Counter driver

System Tick Counter is present on Ralink SoCs RT3352 and MT7620. This
driver has been in 'arch/mips/ralink' directory since the beggining of
Ralink architecture support. However, it can be moved into a more proper
place in 'drivers/clocksource'. Hence add it here adding also support for
compile test targets and reducing LOC in architecture code folder.

Signed-off-by: Sergio Paracuellos <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Daniel Lezcano <[e-mail]>

arch/mips/ralink/Kconfig

···
 # SPDX-License-Identifier: GPL-2.0
 if RALINK
 
-config CLKEVT_RT3352
-	bool
-	depends on SOC_RT305X || SOC_MT7620
-	default y
-	select TIMER_OF
-	select CLKSRC_MMIO
-
 config RALINK_ILL_ACC
 	bool
 	depends on SOC_RT305X

arch/mips/ralink/Makefile

···
 	obj-y += clk.o timer.o
 endif
 
-obj-$(CONFIG_CLKEVT_RT3352) += cevt-rt3352.o
-
 obj-$(CONFIG_RALINK_ILL_ACC) += ill_acc.o
 
 obj-$(CONFIG_IRQ_INTC) += irq.o

arch/mips/ralink/cevt-rt3352.c drivers/clocksource/timer-ralink.c

···
+// SPDX-License-Identifier: GPL-2.0
 /*
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
+ * Ralink System Tick Counter driver present on RT3352 and MT7620 SoCs.
  *
  * Copyright (C) 2013 by John Crispin <[e-mail]>
  */
···
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
-
-#include <asm/mach-ralink/ralink_regs.h>
 
 #define SYSTICK_FREQ		(50 * 1000)
 
···
 static int systick_shutdown(struct clock_event_device *evt);
 
 static int systick_next_event(unsigned long delta,
-				struct clock_event_device *evt)
+			      struct clock_event_device *evt)
 {
 	struct systick_device *sdev;
 	u32 count;
···
 
 static irqreturn_t systick_interrupt(int irq, void *dev_id)
 {
-	struct clock_event_device *dev = (struct clock_event_device *) dev_id;
+	struct clock_event_device *dev = (struct clock_event_device *)dev_id;
 
 	dev->event_handler(dev);
 

drivers/clocksource/Kconfig

···
 	  Enables support for the Cirrus Logic timer block
 	  EP93XX.
 
+config RALINK_TIMER
+	bool "Ralink System Tick Counter"
+	depends on SOC_RT305X || SOC_MT7620 || COMPILE_TEST
+	select CLKSRC_MMIO
+	select TIMER_OF
+	help
+	  Enables support for system tick counter present on
+	  Ralink SoCs RT3352 and MT7620.
+
 endmenu

drivers/clocksource/Makefile

···
 obj-$(CONFIG_GXP_TIMER)			+= timer-gxp.o
 obj-$(CONFIG_CLKSRC_LOONGSON1_PWM)	+= timer-loongson1-pwm.o
 obj-$(CONFIG_EP93XX_TIMER)		+= timer-ep93xx.o
+obj-$(CONFIG_RALINK_TIMER)		+= timer-ralink.o