[PATCH 3.16 033/328] pwm: tiehrpwm: Don't use emulation mode bits to control PWM output

[Ben Hutchings]

3.16.62-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Vignesh R <vigne...@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")
Signed-off-by: Vignesh R <vigne...@ti.com>
Signed-off-by: Thierry Reding <thierry.red...@gmail.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -35,10 +35,6 @@
 #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)
@@ -357,7 +353,7 @@ 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\n",
@@ -365,8 +361,6 @@ 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;
 }
 
@@ -396,9 +390,6 @@ 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);
 }