clocksource: convert SPEAr platforms 16-bit up counting clocksource

Convert SPEAr platforms 16-bit up counting clocksource, which requires
a 16-bit register access read rather than 32-bit.

Acked-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 3 insertions, 14 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index bab25a0ba10..cbc27fb1256 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -884,6 +884,7 @@ config PLAT_SPEAR
         select ARM_AMBA
         select ARCH_REQUIRE_GPIOLIB
         select CLKDEV_LOOKUP
+        select CLKSRC_MMIO
         select GENERIC_CLOCKEVENTS
         select HAVE_CLK
         help
diff --git a/arch/arm/plat-spear/time.c b/arch/arm/plat-spear/time.c
index dbb6e4fff79..0c77e429867 100644
--- a/arch/arm/plat-spear/time.c
+++ b/arch/arm/plat-spear/time.c
@@ -70,19 +70,6 @@ static void clockevent_set_mode(enum clock_event_mode mode,
 static int clockevent_next_event(unsigned long evt,
                                  struct clock_event_device *clk_event_dev);
 
-static cycle_t clocksource_read_cycles(struct clocksource *cs)
-{
-        return (cycle_t) readw(gpt_base + COUNT(CLKSRC));
-}
-
-static struct clocksource clksrc = {
-        .name = "tmr1",
-        .rating = 200,          /* its a pretty decent clock */
-        .read = clocksource_read_cycles,
-        .mask = 0xFFFF,         /* 16 bits */
-        .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
 static void spear_clocksource_init(void)
 {
         u32 tick_rate;
@@ -103,7 +90,8 @@ static void spear_clocksource_init(void)
         writew(val, gpt_base + CR(CLKSRC));
 
         /* register the clocksource */
-        clocksource_register_hz(&clksrc, tick_rate);
+        clocksource_mmio_init(gpt_base + COUNT(CLKSRC), "tmr1", tick_rate,
+                200, 16, clocksource_mmio_readw_up);
 }
 
 static struct clock_event_device clkevt = {