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From: Lokesh Vutla <lokeshvutla@ti.com>
To: "Thierry Reding" <thierry.reding@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: Tony Lindgren <tony@atomide.com>,
	Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-pwm@vger.kernel.org>,
	Sekhar Nori <nsekhar@ti.com>, Lokesh Vutla <lokeshvutla@ti.com>
Subject: [PATCH 3/4] pwm: omap-dmtimer: Do not disable pwm before changing period/duty_cycle
Date: Mon, 24 Feb 2020 10:51:34 +0530	[thread overview]
Message-ID: <20200224052135.17278-4-lokeshvutla@ti.com> (raw)
In-Reply-To: <20200224052135.17278-1-lokeshvutla@ti.com>

Only the Timer control register(TCLR) can be updated only when the timer
is stopped. Registers like Counter register(TCRR), loader register(TLDR),
match register(TMAR) can be updated when the counter is running. Since
TCLR is not updated in pwm_omap_dmtimer_config(), do not stop the
timer for period/duty_cycle update.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 drivers/pwm/pwm-omap-dmtimer.c | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index f13be7216847..58c61559e72f 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -102,7 +102,6 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
 	u32 load_value, match_value;
 	struct clk *fclk;
 	unsigned long clk_rate;
-	bool timer_active;
 
 	dev_dbg(chip->dev, "requested duty cycle: %d ns, period: %d ns\n",
 		duty_ns, period_ns);
@@ -178,25 +177,12 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
 	load_value = (DM_TIMER_MAX - period_cycles) + 1;
 	match_value = load_value + duty_cycles - 1;
 
-	/*
-	 * We MUST stop the associated dual-mode timer before attempting to
-	 * write its registers, but calls to omap_dm_timer_start/stop must
-	 * be balanced so check if timer is active before calling timer_stop.
-	 */
-	timer_active = pm_runtime_active(&omap->dm_timer_pdev->dev);
-	if (timer_active)
-		omap->pdata->stop(omap->dm_timer);
-
 	omap->pdata->set_load(omap->dm_timer, true, load_value);
 	omap->pdata->set_match(omap->dm_timer, true, match_value);
 
 	dev_dbg(chip->dev, "load value: %#08x (%d), match value: %#08x (%d)\n",
 		load_value, load_value,	match_value, match_value);
 
-	/* If config was called while timer was running it must be reenabled. */
-	if (timer_active)
-		pwm_omap_dmtimer_start(omap);
-
 	mutex_unlock(&omap->mutex);
 
 	return 0;
-- 
2.23.0


WARNING: multiple messages have this Message-ID (diff)
From: Lokesh Vutla <lokeshvutla@ti.com>
To: "Thierry Reding" <thierry.reding@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: Tony Lindgren <tony@atomide.com>,
	Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
	linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org,
	Sekhar Nori <nsekhar@ti.com>, Lokesh Vutla <lokeshvutla@ti.com>
Subject: [PATCH 3/4] pwm: omap-dmtimer: Do not disable pwm before changing period/duty_cycle
Date: Mon, 24 Feb 2020 10:51:34 +0530	[thread overview]
Message-ID: <20200224052135.17278-4-lokeshvutla@ti.com> (raw)
In-Reply-To: <20200224052135.17278-1-lokeshvutla@ti.com>

Only the Timer control register(TCLR) can be updated only when the timer
is stopped. Registers like Counter register(TCRR), loader register(TLDR),
match register(TMAR) can be updated when the counter is running. Since
TCLR is not updated in pwm_omap_dmtimer_config(), do not stop the
timer for period/duty_cycle update.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 drivers/pwm/pwm-omap-dmtimer.c | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index f13be7216847..58c61559e72f 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -102,7 +102,6 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
 	u32 load_value, match_value;
 	struct clk *fclk;
 	unsigned long clk_rate;
-	bool timer_active;
 
 	dev_dbg(chip->dev, "requested duty cycle: %d ns, period: %d ns\n",
 		duty_ns, period_ns);
@@ -178,25 +177,12 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
 	load_value = (DM_TIMER_MAX - period_cycles) + 1;
 	match_value = load_value + duty_cycles - 1;
 
-	/*
-	 * We MUST stop the associated dual-mode timer before attempting to
-	 * write its registers, but calls to omap_dm_timer_start/stop must
-	 * be balanced so check if timer is active before calling timer_stop.
-	 */
-	timer_active = pm_runtime_active(&omap->dm_timer_pdev->dev);
-	if (timer_active)
-		omap->pdata->stop(omap->dm_timer);
-
 	omap->pdata->set_load(omap->dm_timer, true, load_value);
 	omap->pdata->set_match(omap->dm_timer, true, match_value);
 
 	dev_dbg(chip->dev, "load value: %#08x (%d), match value: %#08x (%d)\n",
 		load_value, load_value,	match_value, match_value);
 
-	/* If config was called while timer was running it must be reenabled. */
-	if (timer_active)
-		pwm_omap_dmtimer_start(omap);
-
 	mutex_unlock(&omap->mutex);
 
 	return 0;
-- 
2.23.0

  parent reply	other threads:[~2020-02-24  5:22 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-24  5:21 [PATCH 0/4] pwm: omap-dmtimer: Allow for dynamic pwm period updates Lokesh Vutla
2020-02-24  5:21 ` Lokesh Vutla
2020-02-24  5:21 ` [PATCH 1/4] pwm: omap-dmtimer: Drop unused header file Lokesh Vutla
2020-02-24  5:21   ` Lokesh Vutla
2020-02-24  7:53   ` Uwe Kleine-König
2020-02-25  5:02     ` Lokesh Vutla
2020-02-25  5:02       ` Lokesh Vutla
2020-02-25  6:43       ` Uwe Kleine-König
2020-02-24  5:21 ` [PATCH 2/4] pwm: omap-dmtimer: Fix pwm enabling sequence Lokesh Vutla
2020-02-24  5:21   ` Lokesh Vutla
2020-02-24  8:49   ` Uwe Kleine-König
2020-02-25  5:02     ` Lokesh Vutla
2020-02-25  5:02       ` Lokesh Vutla
2020-02-24  5:21 ` Lokesh Vutla [this message]
2020-02-24  5:21   ` [PATCH 3/4] pwm: omap-dmtimer: Do not disable pwm before changing period/duty_cycle Lokesh Vutla
2020-02-24  8:55   ` Uwe Kleine-König
2020-02-25  5:02     ` Lokesh Vutla
2020-02-25  5:02       ` Lokesh Vutla
2020-02-25  6:48       ` Uwe Kleine-König
2020-02-25  7:59         ` Lokesh Vutla
2020-02-25  7:59           ` Lokesh Vutla
2020-02-25  8:38           ` Uwe Kleine-König
2020-02-25 11:26             ` Lokesh Vutla
2020-02-25 11:26               ` Lokesh Vutla
2020-02-26 16:35               ` Uwe Kleine-König
2020-02-24  5:21 ` [PATCH 4/4] pwm: omap-dmtimer: Implement .apply callback Lokesh Vutla
2020-02-24  5:21   ` Lokesh Vutla
2020-02-24  9:07   ` Uwe Kleine-König
2020-02-25  5:01     ` Lokesh Vutla
2020-02-25  5:01       ` Lokesh Vutla
2020-02-26 16:21       ` Uwe Kleine-König
2020-02-26 17:57 ` [PATCH 0/4] pwm: omap-dmtimer: Allow for dynamic pwm period updates Tony Lindgren

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