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    Subject[PATCH 1/6] unicore32: pwm: Properly remap memory-mapped registers
    Date
    Instead of writing to the timer controller registers by dereferencing a
    pointer to the memory location, properly remap the memory region with a
    call to ioremap_nocache() and access the registers using writel().

    Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
    ---
    arch/unicore32/kernel/pwm.c | 25 ++++++++++++++++++++++---
    1 file changed, 22 insertions(+), 3 deletions(-)

    diff --git a/arch/unicore32/kernel/pwm.c b/arch/unicore32/kernel/pwm.c
    index 4615d51..410b786 100644
    --- a/arch/unicore32/kernel/pwm.c
    +++ b/arch/unicore32/kernel/pwm.c
    @@ -23,10 +23,16 @@
    #include <asm/div64.h>
    #include <mach/hardware.h>

    +#define PWCR 0x00
    +#define DCCR 0x04
    +#define PCR 0x08
    +
    struct pwm_device {
    struct list_head node;
    struct platform_device *pdev;

    + void __iomem *base;
    +
    const char *label;
    struct clk *clk;
    int clk_enabled;
    @@ -69,9 +75,11 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
    * before writing to the registers
    */
    clk_enable(pwm->clk);
    - OST_PWMPWCR = prescale;
    - OST_PWMDCCR = pv - dc;
    - OST_PWMPCR = pv;
    +
    + writel(prescale, pwm->base + PWCR);
    + writel(pv - dc, pwm->base + DCCR);
    + writel(pv, pwm->base + PCR);
    +
    clk_disable(pwm->clk);

    return 0;
    @@ -190,10 +198,19 @@ static struct pwm_device *pwm_probe(struct platform_device *pdev,
    goto err_free_clk;
    }

    + pwm->base = ioremap_nocache(r->start, resource_size(r));
    + if (pwm->base == NULL) {
    + dev_err(&pdev->dev, "failed to remap memory resource\n");
    + ret = -EADDRNOTAVAIL;
    + goto err_release_mem;
    + }
    +
    __add_pwm(pwm);
    platform_set_drvdata(pdev, pwm);
    return pwm;

    +err_release_mem:
    + release_mem_region(r->start, resource_size(r));
    err_free_clk:
    clk_put(pwm->clk);
    err_free:
    @@ -224,6 +241,8 @@ static int __devexit pwm_remove(struct platform_device *pdev)
    list_del(&pwm->node);
    mutex_unlock(&pwm_lock);

    + iounmap(pwm->base);
    +
    r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    release_mem_region(r->start, resource_size(r));

    --
    1.7.12


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