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    Subject[RFC PATCH 11/13] m68k: mac: Convert to clocksource API
    Date
    Add a platform clocksource by adapting the existing arch_gettimeoffset
    implementation.

    Cc: Joshua Thompson <funaho@jurai.org>
    Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
    ---
    arch/m68k/mac/via.c | 31 +++++++++++++++++++++++--------
    1 file changed, 23 insertions(+), 8 deletions(-)

    diff --git a/arch/m68k/mac/via.c b/arch/m68k/mac/via.c
    index 7130abec0b77..c4c304470fae 100644
    --- a/arch/m68k/mac/via.c
    +++ b/arch/m68k/mac/via.c
    @@ -23,6 +23,7 @@
    *
    */

    +#include <linux/clocksource.h>
    #include <linux/types.h>
    #include <linux/kernel.h>
    #include <linux/mm.h>
    @@ -556,13 +557,23 @@ EXPORT_SYMBOL(via2_scsi_drq_pending);
    /* timer and clock source */

    #define VIA_CLOCK_FREQ 783360 /* VIA "phase 2" clock in Hz */
    -#define VIA_TIMER_INTERVAL (1000000 / HZ) /* microseconds per jiffy */
    #define VIA_TIMER_CYCLES (VIA_CLOCK_FREQ / HZ) /* clock cycles per jiffy */

    #define VIA_TC (VIA_TIMER_CYCLES - 2) /* including 0 and -1 */
    #define VIA_TC_LOW (VIA_TC & 0xFF)
    #define VIA_TC_HIGH (VIA_TC >> 8)

    +static u64 mac_read_clk(struct clocksource *cs);
    +
    +static struct clocksource mac_clk = {
    + .name = "via1",
    + .rating = 250,
    + .read = mac_read_clk,
    + .mask = CLOCKSOURCE_MASK(32),
    + .flags = CLOCK_SOURCE_IS_CONTINUOUS,
    +};
    +
    +static u32 clk_total;
    static bool lost_timer_intr;

    static irqreturn_t via_timer_handler(int irq, void *data)
    @@ -573,16 +584,18 @@ static irqreturn_t via_timer_handler(int irq, void *data)
    local_irq_save(flags);
    if (lost_timer_intr) {
    lost_timer_intr = false;
    - local_irq_restore(flags);
    - func(irq, data);
    - } else
    - local_irq_restore(flags);
    + clk_total += VIA_TIMER_CYCLES;
    + }
    + clk_total += VIA_TIMER_CYCLES;
    + local_irq_restore(flags);
    +
    return func(irq, data);
    }

    void __init via_init_clock(irq_handler_t func)
    {
    - if (request_irq(IRQ_MAC_TIMER_1, via_timer_handler, 0, "timer", func)) {
    + if (request_irq(IRQ_MAC_TIMER_1, via_timer_handler, IRQF_TIMER,
    + "timer", func)) {
    pr_err("Couldn't register %s interrupt\n", "timer");
    return;
    }
    @@ -592,11 +605,13 @@ void __init via_init_clock(irq_handler_t func)
    via1[vT1CL] = VIA_TC_LOW;
    via1[vT1CH] = VIA_TC_HIGH;
    via1[vACR] |= 0x40;
    +
    + clocksource_register_hz(&mac_clk, VIA_CLOCK_FREQ);
    }

    #define VIA_T1_INT_FLAG BIT(6)

    -u32 mac_gettimeoffset(void)
    +static u64 mac_read_clk(struct clocksource *cs)
    {
    unsigned long flags;
    u8 count_high, count_high_new, count_low;
    @@ -631,5 +646,5 @@ u32 mac_gettimeoffset(void)
    count = ((count_high << 8) | count_low) + 1;
    count = VIA_TIMER_CYCLES - count + offset;

    - return ((count * VIA_TIMER_INTERVAL) / VIA_TIMER_CYCLES) * 1000;
    + return clk_total + count;
    }
    --
    2.18.1
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