linux-kernel - [PATCH v1 1/2] pinctrl: cherryview: Avoid duplicated I/O

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Message-Id: <20231006094033.3082468-1-andriy.shevchenko@linux.intel.com>
Date:   Fri,  6 Oct 2023 12:40:32 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Andy Shevchenko <andy@...nel.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Raag Jadav <raag.jadav@...el.com>
Subject: [PATCH v1 1/2] pinctrl: cherryview: Avoid duplicated I/O

In some cases we already read the value from the register followed
by a reading of it again for other purposes, but the both reads
are under the lock and bits we are insterested in are not going
to change (they are not volatile from HW perspective). Hence, no
need to read the same registeer twice.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 drivers/pinctrl/intel/pinctrl-cherryview.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/pinctrl/intel/pinctrl-cherryview.c b/drivers/pinctrl/intel/pinctrl-cherryview.c
index f047f7bf4afb..9b9f18f50c1d 100644
--- a/drivers/pinctrl/intel/pinctrl-cherryview.c
+++ b/drivers/pinctrl/intel/pinctrl-cherryview.c
@@ -612,9 +612,14 @@ static void chv_writel(struct intel_pinctrl *pctrl, unsigned int pin, unsigned i
 }
 
 /* When Pad Cfg is locked, driver can only change GPIOTXState or GPIORXState */
+static bool chv_pad_is_locked(u32 ctrl1)
+{
+	return ctrl1 & CHV_PADCTRL1_CFGLOCK;
+}
+
 static bool chv_pad_locked(struct intel_pinctrl *pctrl, unsigned int offset)
 {
-	return chv_readl(pctrl, offset, CHV_PADCTRL1) & CHV_PADCTRL1_CFGLOCK;
+	return chv_pad_is_locked(chv_readl(pctrl, offset, CHV_PADCTRL1));
 }
 
 static void chv_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
@@ -623,13 +628,11 @@ static void chv_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
 	struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
 	unsigned long flags;
 	u32 ctrl0, ctrl1;
-	bool locked;
 
 	raw_spin_lock_irqsave(&chv_lock, flags);
 
 	ctrl0 = chv_readl(pctrl, offset, CHV_PADCTRL0);
 	ctrl1 = chv_readl(pctrl, offset, CHV_PADCTRL1);
-	locked = chv_pad_locked(pctrl, offset);
 
 	raw_spin_unlock_irqrestore(&chv_lock, flags);
 
@@ -646,7 +649,7 @@ static void chv_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
 
 	seq_printf(s, "0x%08x 0x%08x", ctrl0, ctrl1);
 
-	if (locked)
+	if (chv_pad_is_locked(ctrl1))
 		seq_puts(s, " [LOCKED]");
 }
 
-- 
2.40.0.1.gaa8946217a0b