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    Subject[PATCH 4.14 75/89] pwm: tiehrpwm: Dont use emulation mode bits to control PWM output
    Date
    4.14-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Vignesh R <vigneshr@ti.com>

    commit aa49d628f6e016bcec8c6f8e704b9b18ee697329 upstream.

    As per AM335x TRM SPRUH73P "15.2.2.11 ePWM Behavior During Emulation",
    TBCTL[15:14] only have effect during emulation suspend events (IOW,
    to stop PWM when debugging using a debugger). These bits have no effect
    on PWM output during normal running of system. Hence, remove code
    accessing these bits as they have no role in enabling/disabling PWMs.

    Fixes: 19891b20e7c2 ("pwm: pwm-tiehrpwm: PWM driver support for EHRPWM")
    Cc: stable@vger.kernel.org
    Signed-off-by: Vignesh R <vigneshr@ti.com>
    Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/pwm/pwm-tiehrpwm.c | 12 +-----------
    1 file changed, 1 insertion(+), 11 deletions(-)

    --- a/drivers/pwm/pwm-tiehrpwm.c
    +++ b/drivers/pwm/pwm-tiehrpwm.c
    @@ -33,10 +33,6 @@
    #define TBCTL 0x00
    #define TBPRD 0x0A

    -#define TBCTL_RUN_MASK (BIT(15) | BIT(14))
    -#define TBCTL_STOP_NEXT 0
    -#define TBCTL_STOP_ON_CYCLE BIT(14)
    -#define TBCTL_FREE_RUN (BIT(15) | BIT(14))
    #define TBCTL_PRDLD_MASK BIT(3)
    #define TBCTL_PRDLD_SHDW 0
    #define TBCTL_PRDLD_IMDT BIT(3)
    @@ -360,7 +356,7 @@ static int ehrpwm_pwm_enable(struct pwm_
    /* Channels polarity can be configured from action qualifier module */
    configure_polarity(pc, pwm->hwpwm);

    - /* Enable TBCLK before enabling PWM device */
    + /* Enable TBCLK */
    ret = clk_enable(pc->tbclk);
    if (ret) {
    dev_err(chip->dev, "Failed to enable TBCLK for %s: %d\n",
    @@ -368,9 +364,6 @@ static int ehrpwm_pwm_enable(struct pwm_
    return ret;
    }

    - /* Enable time counter for free_run */
    - ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_FREE_RUN);
    -
    return 0;
    }

    @@ -400,9 +393,6 @@ static void ehrpwm_pwm_disable(struct pw
    /* Disabling TBCLK on PWM disable */
    clk_disable(pc->tbclk);

    - /* Stop Time base counter */
    - ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_STOP_NEXT);
    -
    /* Disable clock on PWM disable */
    pm_runtime_put_sync(chip->dev);
    }

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