[PATCH] i2c: cadence: fix call balance of id->clk handling routines

[Vitalii Mordan]

If the clock id->clk was not enabled in cdns_i2c_probe(), it should not be
disabled in any execution path. If the clock was not enabled, the probe
function should return an error code.

Use the devm_clk_get_enabled() helper function to ensure proper call
balance for id->clk.

Found by Linux Verification Center (linuxtesting.org) with Klever.

Fixes: df8eb5691c48 ("i2c: Add driver for Cadence I2C controller")
Signed-off-by: Vitalii Mordan <mordan at ispras.ru>
---
 drivers/i2c/busses/i2c-cadence.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index b64026fbca66..07564a962dcb 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -1541,7 +1541,7 @@ static int cdns_i2c_probe(struct platform_device *pdev)
 	snprintf(id->adap.name, sizeof(id->adap.name),
 		 "Cadence I2C at %08lx", (unsigned long)r_mem->start);
 
-	id->clk = devm_clk_get(&pdev->dev, NULL);
+	id->clk = devm_clk_get_enabled(&pdev->dev, NULL);
 	if (IS_ERR(id->clk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(id->clk),
 				     "input clock not found.\n");
@@ -1551,10 +1551,6 @@ static int cdns_i2c_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(id->reset),
 				     "Failed to request reset.\n");
 
-	ret = clk_prepare_enable(id->clk);
-	if (ret)
-		dev_err(&pdev->dev, "Unable to enable clock.\n");
-
 	ret = reset_control_deassert(id->reset);
 	if (ret) {
 		dev_err_probe(&pdev->dev, ret,
@@ -1617,7 +1613,6 @@ static int cdns_i2c_probe(struct platform_device *pdev)
 	clk_notifier_unregister(id->clk, &id->clk_rate_change_nb);
 	reset_control_assert(id->reset);
 err_clk_dis:
-	clk_disable_unprepare(id->clk);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 	return ret;
@@ -1642,7 +1637,6 @@ static void cdns_i2c_remove(struct platform_device *pdev)
 	i2c_del_adapter(&id->adap);
 	clk_notifier_unregister(id->clk, &id->clk_rate_change_nb);
 	reset_control_assert(id->reset);
-	clk_disable_unprepare(id->clk);
 }
 
 static struct platform_driver cdns_i2c_drv = {
-- 
2.25.1