[PATCH v1] clocksource/drivers/timer-atmel-pit: Fix init failure cleanup

[Yuho Choi <dbgh9129@gmail.com>]

After clk_prepare_enable(data->mck) succeeds, at91sam926x_pit_dt_init()
can still fail while parsing the IRQ, registering the clocksource, or
requesting the IRQ. These paths only free the driver data, leaving the
master clock enabled.

Unwind each initialized state on failure. Stop the PIT after it has been
started, dispose the IRQ mapping after it has been created, disable and
put the master clock, and unmap the registers before freeing the driver
data.

Fixes: 699e36e5b8e9 ("clocksource/drivers/timer-atmel-pit: Enable mck clock")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
---
 drivers/clocksource/timer-atmel-pit.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/timer-atmel-pit.c b/drivers/clocksource/timer-atmel-pit.c
index 888b06731e54..edd427ab93e6 100644
--- a/drivers/clocksource/timer-atmel-pit.c
+++ b/drivers/clocksource/timer-atmel-pit.c
@@ -12,7 +12,9 @@
 #include <linux/clk.h>
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
+#include <linux/io.h>
 #include <linux/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
@@ -185,13 +187,13 @@ static int __init at91sam926x_pit_dt_init(struct device_node *node)
 	if (IS_ERR(data->mck)) {
 		pr_err("Unable to get mck clk\n");
 		ret = PTR_ERR(data->mck);
-		goto exit;
+		goto exit_iounmap;
 	}
 
 	ret = clk_prepare_enable(data->mck);
 	if (ret) {
 		pr_err("Unable to enable mck\n");
-		goto exit;
+		goto exit_clk_put;
 	}
 
 	/* Get the interrupts property */
@@ -199,7 +201,7 @@ static int __init at91sam926x_pit_dt_init(struct device_node *node)
 	if (!data->irq) {
 		pr_err("Unable to get IRQ from DT\n");
 		ret = -EINVAL;
-		goto exit;
+		goto exit_clk_disable;
 	}
 
 	/*
@@ -227,7 +229,7 @@ static int __init at91sam926x_pit_dt_init(struct device_node *node)
 	ret = clocksource_register_hz(&data->clksrc, pit_rate);
 	if (ret) {
 		pr_err("Failed to register clocksource\n");
-		goto exit;
+		goto exit_pit_disable;
 	}
 
 	/* Set up irq handler */
@@ -237,7 +239,7 @@ static int __init at91sam926x_pit_dt_init(struct device_node *node)
 	if (ret) {
 		pr_err("Unable to setup IRQ\n");
 		clocksource_unregister(&data->clksrc);
-		goto exit;
+		goto exit_pit_disable;
 	}
 
 	/* Set up and register clockevents */
@@ -256,6 +258,15 @@ static int __init at91sam926x_pit_dt_init(struct device_node *node)
 
 	return 0;
 
+exit_pit_disable:
+	pit_write(data->base, AT91_PIT_MR, 0);
+	irq_dispose_mapping(data->irq);
+exit_clk_disable:
+	clk_disable_unprepare(data->mck);
+exit_clk_put:
+	clk_put(data->mck);
+exit_iounmap:
+	iounmap(data->base);
 exit:
 	kfree(data);
 	return ret;
-- 
2.43.0