linux-kernel - [PATCH] pwm: core: Use pwm->args.polarity to setup PWM_POLARITY

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Date:   Thu,  6 Oct 2016 08:49:54 +0200
From:   Lukasz Majewski <l.majewski@...ess.pl>
To:     Bhuvanchandra DV <bhuvanchandra.dv@...adex.com>, stefan@...er.ch
Cc:     <shawnguo@...nel.org>, <thierry.reding@...il.com>,
        mark.rutland@....com, linux-pwm@...r.kernel.org,
        l.majewski@...sung.com, linux-kernel@...r.kernel.org,
        robh+dt@...nel.org, kernel@...gutronix.de, fabio.estevam@....com,
        linux-arm-kernel@...ts.infradead.org,
        Lothar Wassmann <LW@...O-electronics.de>,
        Lukasz Majewski <l.majewski@...ess.pl>
Subject: [PATCH] pwm: core: Use pwm->args.polarity to setup PWM_POLARITY_INVERSED

The pwm_set_polarity() function finally calls pwm_apply_state(), which
in turn requires state->duty_cycle and state->period properly set.

In the moment when polarity is set, the PWM is disabled and not configured.
For that reason both above variables are set to 0 and the polarity is not
set.

To be sure that polarity is setup, one needs to set pwm->args.polarity, which
controls MX3_PWMCR_POUTC bit setting at imx_pwm_config_v2().

Signed-off-by: Lukasz Majewski <l.majewski@...ess.pl>
---
This patch should be applied on top of:

"[v2,2/6] pwm: core: make the PWM_POLARITY flag in DTB optional"

http://patchwork.ozlabs.org/patch/677330/

---
 drivers/pwm/core.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 1f62668..6cd6004 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -153,13 +153,11 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
 		return pwm;
 
 	pwm->args.period = args->args[1];
+	pwm->args.polarity = PWM_POLARITY_NORMAL;
 
-	if (args->args_count > 2) {
+	if (args->args_count > 2)
 		if (args->args[2] & PWM_POLARITY_INVERTED)
-			pwm_set_polarity(pwm, PWM_POLARITY_INVERSED);
-		else
-			pwm_set_polarity(pwm, PWM_POLARITY_NORMAL);
-	}
+			pwm->args.polarity = PWM_POLARITY_INVERSED;
 
 	return pwm;
 }
-- 
2.1.4