linux-kernel - [PATCH v2 4/4] pwm: sysfs: Utilize an array for polarity strings

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Message-Id: <20220826170716.6886-4-andriy.shevchenko@linux.intel.com>
Date:   Fri, 26 Aug 2022 20:07:16 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        linux-pwm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Thierry Reding <thierry.reding@...il.com>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>
Subject: [PATCH v2 4/4] pwm: sysfs: Utilize an array for polarity strings

Code is smaller and looks nicer if we combine polarity strings
into an array.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
v2: added pwm_ prefix to the variable (Uwe), adjusted intendation (Uwe)
 drivers/pwm/sysfs.c | 32 ++++++++++++--------------------
 1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index 767c4b19afb1..502167e44a3d 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c
@@ -151,27 +151,23 @@ static ssize_t enable_store(struct device *child,
 	return ret ? : size;
 }
 
+static const char * const pwm_polarity_strings[] = {
+	[PWM_POLARITY_NORMAL] = "normal",
+	[PWM_POLARITY_INVERSED] = "inversed",
+};
+
 static ssize_t polarity_show(struct device *child,
 			     struct device_attribute *attr,
 			     char *buf)
 {
 	const struct pwm_device *pwm = child_to_pwm_device(child);
-	const char *polarity = "unknown";
 	struct pwm_state state;
 
 	pwm_get_state(pwm, &state);
+	if (state.polarity < 0 || state.polarity >= ARRAY_SIZE(pwm_polarity_strings))
+		return sysfs_emit(buf, "unknown\n");
 
-	switch (state.polarity) {
-	case PWM_POLARITY_NORMAL:
-		polarity = "normal";
-		break;
-
-	case PWM_POLARITY_INVERSED:
-		polarity = "inversed";
-		break;
-	}
-
-	return sysfs_emit(buf, "%s\n", polarity);
+	return sysfs_emit(buf, "%s\n", pwm_polarity_strings[state.polarity]);
 }
 
 static ssize_t polarity_store(struct device *child,
@@ -180,20 +176,16 @@ static ssize_t polarity_store(struct device *child,
 {
 	struct pwm_export *export = child_to_pwm_export(child);
 	struct pwm_device *pwm = export->pwm;
-	enum pwm_polarity polarity;
 	struct pwm_state state;
 	int ret;
 
-	if (sysfs_streq(buf, "normal"))
-		polarity = PWM_POLARITY_NORMAL;
-	else if (sysfs_streq(buf, "inversed"))
-		polarity = PWM_POLARITY_INVERSED;
-	else
-		return -EINVAL;
+	ret = sysfs_match_string(pwm_polarity_strings, buf);
+	if (ret < 0)
+		return ret;
 
 	mutex_lock(&export->lock);
 	pwm_get_state(pwm, &state);
-	state.polarity = polarity;
+	state.polarity = ret;
 	ret = pwm_apply_state(pwm, &state);
 	mutex_unlock(&export->lock);
 
-- 
2.35.1