i2c: imx: use guard to take spinlock

JIRA: https://issues.redhat.com/browse/RHEL-116101

commit 07e0e8e
Author: Troy Mitchell <troymitchell988@gmail.com>
Date:   Sat May 31 14:57:26 2025 +0800

    i2c: imx: use guard to take spinlock

    Use guard to automatically release the lock after going out of scope
    instead of calling it manually.

    i2c_imx_slave_handle() can safely be entered with the lock held.

    Refactored the i2c_imx_isr function so that i2c_imx_master_isr
    does not participate in the guard scope

    So Using scoped_guard simplifies the control flow
    by ensuring consistent and automatic unlock,
    which improves readability without affecting correctness.

    Co-developed-by: Yongchao Jia <jyc0019@gmail.com>
    Signed-off-by: Yongchao Jia <jyc0019@gmail.com>
    Signed-off-by: Troy Mitchell <troymitchell988@gmail.com>
    Reviewed-by: Frank Li <Frank.Li@nxp.com>
    Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
    Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
    Link: https://lore.kernel.org/r/20250531-i2c-imx-update-v4-1-bfad0c8fd45c@gmail.com

Signed-off-by: Jared Kangas <jkangas@redhat.com>

Author: rh-jkangas

drivers/i2c/busses/i2c-imx.c

@@ -23,6 +23,7 @@
 
 #include <linux/acpi.h>
 #include <linux/clk.h>
+#include <linux/cleanup.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
@@ -891,13 +892,13 @@ static enum hrtimer_restart i2c_imx_slave_timeout(struct hrtimer *t)
 	struct imx_i2c_struct *i2c_imx = container_of(t, struct imx_i2c_struct,
 						      slave_timer);
 	unsigned int ctl, status;
-	unsigned long flags;
 
-	spin_lock_irqsave(&i2c_imx->slave_lock, flags);
+	guard(spinlock_irqsave)(&i2c_imx->slave_lock);
+
 	status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
 	ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 	i2c_imx_slave_handle(i2c_imx, status, ctl);
-	spin_unlock_irqrestore(&i2c_imx->slave_lock, flags);
+
 	return HRTIMER_NORESTART;
 }
 
@@ -1126,32 +1127,26 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
 {
 	struct imx_i2c_struct *i2c_imx = dev_id;
 	unsigned int ctl, status;
-	unsigned long flags;
 
-	spin_lock_irqsave(&i2c_imx->slave_lock, flags);
-	status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
-	ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+	scoped_guard(spinlock_irqsave, &i2c_imx->slave_lock) {
+		status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+		ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+
+		if (!(status & I2SR_IIF))
+			return IRQ_NONE;
 
-	if (status & I2SR_IIF) {
 		i2c_imx_clear_irq(i2c_imx, I2SR_IIF);
+
 		if (i2c_imx->slave) {
-			if (!(ctl & I2CR_MSTA)) {
-				irqreturn_t ret;
-
-				ret = i2c_imx_slave_handle(i2c_imx,
-							   status, ctl);
-				spin_unlock_irqrestore(&i2c_imx->slave_lock,
-						       flags);
-				return ret;
-			}
+			if (!(ctl & I2CR_MSTA))
+				return i2c_imx_slave_handle(i2c_imx,
+							    status, ctl);
+
 			i2c_imx_slave_finish_op(i2c_imx);
 		}
-		spin_unlock_irqrestore(&i2c_imx->slave_lock, flags);
-		return i2c_imx_master_isr(i2c_imx, status);
 	}
-	spin_unlock_irqrestore(&i2c_imx->slave_lock, flags);
 
-	return IRQ_NONE;
+	return i2c_imx_master_isr(i2c_imx, status);
 }
 
 static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,