Re: [PATCH 2/2] clocksource: sprd: Add timer driver for Spreadtrum SC9860 platform

[kbuild test robot]

Hi Baolin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on tip/timers/core]
[also build test WARNING on v4.14 next-20171124]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Baolin-Wang/dt-bindings-clocksource-Add-Spreadtrum-SC9860-timer/20171125-090749
config: i386-allmodconfig (attached as .config)
compiler: gcc-6 (Debian 6.4.0-9) 6.4.0 20171026
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All warnings (new ones prefixed by >>):

   In file included from arch/x86/include/asm/realmode.h:14:0,
                    from arch/x86/include/asm/acpi.h:33,
                    from arch/x86/include/asm/fixmap.h:19,
                    from arch/x86/include/asm/apic.h:10,
                    from arch/x86/include/asm/smp.h:12,
                    from include/linux/smp.h:63,
                    from include/linux/topology.h:33,
                    from include/linux/gfp.h:8,
                    from include/linux/idr.h:16,
                    from include/linux/kernfs.h:14,
                    from include/linux/sysfs.h:15,
                    from include/linux/kobject.h:21,
                    from include/linux/of.h:21,
                    from include/linux/clocksource.h:18,
                    from drivers/clocksource/sprd-timer.c:7:
   drivers/clocksource/sprd-timer.c: In function 'sprd_timer_update_counter':
>> drivers/clocksource/sprd-timer.c:85:24: warning: right shift count >= width of type [-Wshift-count-overflow]
     writel_relaxed(cycles >> TIMER_VALUE_HI_SHIFT,
                           ^
   arch/x86/include/asm/io.h:87:39: note: in definition of macro 'writel_relaxed'
    #define writel_relaxed(v, a) __writel(v, a)
                                          ^

vim +85 drivers/clocksource/sprd-timer.c

   > 7	#include <linux/clocksource.h>
     8	#include <linux/clockchips.h>
     9	#include <linux/init.h>
    10	#include <linux/interrupt.h>
    11	#include <linux/sched_clock.h>
    12	#include <linux/slab.h>
    13	#include <linux/of.h>
    14	#include <linux/of_address.h>
    15	#include <linux/of_irq.h>
    16	
    17	#define TIMER_NAME		"sprd_timer"
    18	
    19	#define TIMER_LOAD_LO		0x0
    20	#define TIMER_LOAD_HI		0x4
    21	#define TIMER_VALUE_LO		0x8
    22	#define TIMER_VALUE_HI		0xc
    23	
    24	#define TIMER_CTL		0x10
    25	#define TIMER_CTL_PERIOD_MODE	BIT(0)
    26	#define TIMER_CTL_ENABLE	BIT(1)
    27	#define TIMER_CTL_64BIT_WIDTH	BIT(16)
    28	
    29	#define TIMER_INT		0x14
    30	#define TIMER_INT_EN		BIT(0)
    31	#define TIMER_INT_RAW_STS	BIT(1)
    32	#define TIMER_INT_MASK_STS	BIT(2)
    33	#define TIMER_INT_CLR		BIT(3)
    34	
    35	#define TIMER_VALUE_SHDW_LO	0x18
    36	#define TIMER_VALUE_SHDW_HI	0x1c
    37	
    38	#define TIMER_VALUE_LO_MASK	GENMASK(31, 0)
    39	#define TIMER_VALUE_HI_SHIFT	32
    40	
    41	struct sprd_timer_device {
    42		struct clock_event_device ce;
    43		void __iomem *base;
    44		u32 freq;
    45		int irq;
    46	};
    47	
    48	static inline struct sprd_timer_device *
    49	to_sprd_timer(struct clock_event_device *c)
    50	{
    51		return container_of(c, struct sprd_timer_device, ce);
    52	}
    53	
    54	static void sprd_timer_enable(struct sprd_timer_device *timer, u32 flag)
    55	{
    56		u32 val = readl_relaxed(timer->base + TIMER_CTL);
    57	
    58		val |= TIMER_CTL_ENABLE;
    59		if (flag & TIMER_CTL_64BIT_WIDTH)
    60			val |= TIMER_CTL_64BIT_WIDTH;
    61		else
    62			val &= ~TIMER_CTL_64BIT_WIDTH;
    63	
    64		if (flag & TIMER_CTL_PERIOD_MODE)
    65			val |= TIMER_CTL_PERIOD_MODE;
    66		else
    67			val &= ~TIMER_CTL_PERIOD_MODE;
    68	
    69		writel_relaxed(val, timer->base + TIMER_CTL);
    70	}
    71	
    72	static void sprd_timer_disable(struct sprd_timer_device *timer)
    73	{
    74		u32 val = readl_relaxed(timer->base + TIMER_CTL);
    75	
    76		val &= ~TIMER_CTL_ENABLE;
    77		writel_relaxed(val, timer->base + TIMER_CTL);
    78	}
    79	
    80	static void sprd_timer_update_counter(struct sprd_timer_device *timer,
    81					      unsigned long cycles)
    82	{
    83		writel_relaxed(cycles & TIMER_VALUE_LO_MASK,
    84			       timer->base + TIMER_LOAD_LO);
  > 85		writel_relaxed(cycles >> TIMER_VALUE_HI_SHIFT,
    86			       timer->base + TIMER_LOAD_HI);
    87	}
    88	

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0-DAY kernel test infrastructure                Open Source Technology Center
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