libata: pata_pdc2027x PLL input clock fix

[pandora-kernel.git] / drivers / ata / pata_pdc2027x.c

diff --git a/drivers/ata/pata_pdc2027x.c b/drivers/ata/pata_pdc2027x.c
index 0d2cc49..69a5aa4 100644 (file)
--- a/drivers/ata/pata_pdc2027x.c
+++ b/drivers/ata/pata_pdc2027x.c
@@ -689,10 +689,12 @@ static long pdc_detect_pll_input_clock(struct ata_host *host)
        void __iomem *mmio_base = host->iomap[PDC_MMIO_BAR];
        u32 scr;
        long start_count, end_count;
-       long pll_clock;
+       struct timeval start_time, end_time;
+       long pll_clock, usec_elapsed;
 
        /* Read current counter value */
        start_count = pdc_read_counter(host);
+       do_gettimeofday(&start_time);
 
        /* Start the test mode */
        scr = readl(mmio_base + PDC_SYS_CTL);
@@ -705,6 +707,7 @@ static long pdc_detect_pll_input_clock(struct ata_host *host)
 
        /* Read the counter values again */
        end_count = pdc_read_counter(host);
+       do_gettimeofday(&end_time);
 
        /* Stop the test mode */
        scr = readl(mmio_base + PDC_SYS_CTL);
@@ -713,7 +716,11 @@ static long pdc_detect_pll_input_clock(struct ata_host *host)
        readl(mmio_base + PDC_SYS_CTL); /* flush */
 
        /* calculate the input clock in Hz */
-       pll_clock = (start_count - end_count) * 10;
+       usec_elapsed = (end_time.tv_sec - start_time.tv_sec) * 1000000 +
+               (end_time.tv_usec - start_time.tv_usec);
+
+       pll_clock = (start_count - end_count) / 100 *
+               (100000000 / usec_elapsed);
 
        PDPRINTK("start[%ld] end[%ld] \n", start_count, end_count);
        PDPRINTK("PLL input clock[%ld]Hz\n", pll_clock);