linux-kernel - [PATCH v3 02/11] pwm: imx: remove ipg clock

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Message-Id: <1477984230-18071-3-git-send-email-l.majewski@majess.pl>
Date:   Tue,  1 Nov 2016 08:10:21 +0100
From:   Lukasz Majewski <l.majewski@...ess.pl>
To:     Thierry Reding <thierry.reding@...il.com>,
        Stefan Agner <stefan@...er.ch>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Boris Brezillon <boris.brezillon@...e-electrons.com>
Cc:     linux-pwm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Fabio Estevam <fabio.estevam@....com>,
        Fabio Estevam <festevam@...il.com>,
        Lothar Wassmann <LW@...o-electronics.de>,
        Bhuvanchandra DV <bhuvanchandra.dv@...adex.com>,
        kernel@...gutronix.de, Lukasz Majewski <l.majewski@...ess.pl>,
        Lothar Waßmann <LW@...O-electronics.de>,
        Philipp Zabel <p.zabel@...gutronix.de>
Subject: [PATCH v3 02/11] pwm: imx: remove ipg clock

From: Sascha Hauer <s.hauer@...gutronix.de>

The use of the ipg clock was introduced with commit 7b27c160c681
("pwm: i.MX: fix clock lookup").
In the commit message it was claimed that the ipg clock is enabled for
register accesses. This is true for the ->config() callback, but not
for the ->set_enable() callback. Given that the ipg clock is not
consistently enabled for all register accesses we can assume that either
it is not required at all or that the current code does not work.
Remove the ipg clock code for now so that it's no longer in the way of
refactoring the driver.

Signed-off-by: Sascha Hauer <s.hauer@...gutronix.de>
Cc: Philipp Zabel <p.zabel@...gutronix.de>
---
[commit message text refactored by Lukasz Majewski <l.majewski@...ess.pl>]
---
Changes for v3:
- New patch
---
 drivers/pwm/pwm-imx.c | 19 +------------------
 1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index d600fd5..70609ef2 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -49,7 +49,6 @@
 
 struct imx_chip {
 	struct clk	*clk_per;
-	struct clk	*clk_ipg;
 
 	void __iomem	*mmio_base;
 
@@ -204,17 +203,8 @@ static int imx_pwm_config(struct pwm_chip *chip,
 		struct pwm_device *pwm, int duty_ns, int period_ns)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
-	int ret;
-
-	ret = clk_prepare_enable(imx->clk_ipg);
-	if (ret)
-		return ret;
 
-	ret = imx->config(chip, pwm, duty_ns, period_ns);
-
-	clk_disable_unprepare(imx->clk_ipg);
-
-	return ret;
+	return imx->config(chip, pwm, duty_ns, period_ns);
 }
 
 static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
@@ -293,13 +283,6 @@ static int imx_pwm_probe(struct platform_device *pdev)
 		return PTR_ERR(imx->clk_per);
 	}
 
-	imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
-	if (IS_ERR(imx->clk_ipg)) {
-		dev_err(&pdev->dev, "getting ipg clock failed with %ld\n",
-				PTR_ERR(imx->clk_ipg));
-		return PTR_ERR(imx->clk_ipg);
-	}
-
 	imx->chip.ops = &imx_pwm_ops;
 	imx->chip.dev = &pdev->dev;
 	imx->chip.base = -1;
-- 
2.1.4