linux-kernel - [PATCH] serial: mctrl_gpio: Remove unused mctrl_gpio

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Message-ID: <20250129020048.245529-1-linux@treblig.org>
Date: Wed, 29 Jan 2025 02:00:48 +0000
From: linux@...blig.org
To: gregkh@...uxfoundation.org,
	jirislaby@...nel.org,
	linus.walleij@...aro.org,
	brgl@...ev.pl
Cc: corbet@....net,
	linux-serial@...r.kernel.org,
	linux-gpio@...r.kernel.org,
	linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	"Dr. David Alan Gilbert" <linux@...blig.org>
Subject: [PATCH] serial: mctrl_gpio: Remove unused mctrl_gpio_free

From: "Dr. David Alan Gilbert" <linux@...blig.org>

mctrl_gpio_free() was added in 2014 by
commit 84130aace839 ("tty/serial: Add GPIOLIB helpers for controlling
modem lines")

It does have a comment saying:
  '- * Normally, this function will not be called, as the GPIOs will
   - * be disposed of by the resource management code.'

indeed, it doesn't seem to have been used since it was added.

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@...blig.org>
---
 Documentation/driver-api/serial/driver.rst |  2 +-
 drivers/tty/serial/serial_mctrl_gpio.c     | 28 +---------------------
 drivers/tty/serial/serial_mctrl_gpio.h     | 16 ++-----------
 3 files changed, 4 insertions(+), 42 deletions(-)

diff --git a/Documentation/driver-api/serial/driver.rst b/Documentation/driver-api/serial/driver.rst
index 84b43061c11b..df353211fc6b 100644
--- a/Documentation/driver-api/serial/driver.rst
+++ b/Documentation/driver-api/serial/driver.rst
@@ -101,6 +101,6 @@ Modem control lines via GPIO
 Some helpers are provided in order to set/get modem control lines via GPIO.
 
 .. kernel-doc:: drivers/tty/serial/serial_mctrl_gpio.c
-   :identifiers: mctrl_gpio_init mctrl_gpio_free mctrl_gpio_to_gpiod
+   :identifiers: mctrl_gpio_init mctrl_gpio_to_gpiod
            mctrl_gpio_set mctrl_gpio_get mctrl_gpio_enable_ms
            mctrl_gpio_disable_ms
diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
index 8855688a5b6c..85c172ad1de9 100644
--- a/drivers/tty/serial/serial_mctrl_gpio.c
+++ b/drivers/tty/serial/serial_mctrl_gpio.c
@@ -217,7 +217,7 @@ static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context)
  *
  * This will get the {cts,rts,...}-gpios from device tree if they are present
  * and request them, set direction etc, and return an allocated structure.
- * `devm_*` functions are used, so there's no need to call mctrl_gpio_free().
+ * `devm_*` functions are used, so there's no need to explicitly free.
  * As this sets up the irq handling, make sure to not handle changes to the
  * gpio input lines in your driver, too.
  */
@@ -267,32 +267,6 @@ struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
 }
 EXPORT_SYMBOL_GPL(mctrl_gpio_init);
 
-/**
- * mctrl_gpio_free - explicitly free uart gpios
- * @dev: uart port's device
- * @gpios: gpios structure to be freed
- *
- * This will free the requested gpios in mctrl_gpio_init(). As `devm_*`
- * functions are used, there's generally no need to call this function.
- */
-void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
-{
-	enum mctrl_gpio_idx i;
-
-	if (gpios == NULL)
-		return;
-
-	for (i = 0; i < UART_GPIO_MAX; i++) {
-		if (gpios->irq[i])
-			devm_free_irq(gpios->port->dev, gpios->irq[i], gpios);
-
-		if (gpios->gpio[i])
-			devm_gpiod_put(dev, gpios->gpio[i]);
-	}
-	devm_kfree(dev, gpios);
-}
-EXPORT_SYMBOL_GPL(mctrl_gpio_free);
-
 /**
  * mctrl_gpio_enable_ms - enable irqs and handling of changes to the ms lines
  * @gpios: gpios to enable
diff --git a/drivers/tty/serial/serial_mctrl_gpio.h b/drivers/tty/serial/serial_mctrl_gpio.h
index fc76910fb105..ec4170084766 100644
--- a/drivers/tty/serial/serial_mctrl_gpio.h
+++ b/drivers/tty/serial/serial_mctrl_gpio.h
@@ -59,7 +59,7 @@ struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
 /*
  * Request and set direction of modem control line GPIOs and set up irq
  * handling.
- * devm_* functions are used, so there's no need to call mctrl_gpio_free().
+ * devm_* functions are used, so there's no need to explicitly free.
  * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
  * allocation error.
  */
@@ -67,20 +67,13 @@ struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx);
 
 /*
  * Request and set direction of modem control line GPIOs.
- * devm_* functions are used, so there's no need to call mctrl_gpio_free().
+ * devm_* functions are used, so there's no need to explicitly free.
  * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
  * allocation error.
  */
 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev,
 					   unsigned int idx);
 
-/*
- * Free the mctrl_gpios structure.
- * Normally, this function will not be called, as the GPIOs will
- * be disposed of by the resource management code.
- */
-void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
-
 /*
  * Enable gpio interrupts to report status line changes.
  */
@@ -139,11 +132,6 @@ struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
 	return NULL;
 }
 
-static inline
-void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
-{
-}
-
 static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
 {
 }
-- 
2.48.1