[PATCH v4] i2c: designware-platdrv: simplify reset control and error handling

[Artem Shimko <a.shimko.dev@gmail.com>]

The current implementation uses separate calls to acquire and deassert
reset control, requiring manual error handling for the deassertion
operation. This can be simplified using the dedicated devm function that
combines both operations.

Replace devm_reset_control_get_optional_exclusive() with
devm_reset_control_get_optional_exclusive_deasserted(), which handles both
reset acquisition and deassertion in a single call as well as
reset_control_put() which is called automatically on driver detach. This
eliminates the need for explicit deassertion and its associated error
checking while maintaining the same functional behavior through automatic
resource management.

As part of this cleanup, streamline the error handling by removing goto
exit_reset and goto exit_probe labels, using direct returns with
dev_err_probe() for cleaner and more linear code flow.

Suggested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com>
---

Oh sorry Philipp, now I got it

If you have a time, could you please have a look at this version?

Thank you!

--
Regards,
Artem

 drivers/i2c/busses/i2c-designware-platdrv.c | 43 +++++++--------------
 1 file changed, 14 insertions(+), 29 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 34d881572351..147eda5f5268 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -236,40 +236,32 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	dev->rst = devm_reset_control_get_optional_exclusive(device, NULL);
+	dev->rst = devm_reset_control_get_optional_exclusive_deasserted(device, NULL);
 	if (IS_ERR(dev->rst))
-		return dev_err_probe(device, PTR_ERR(dev->rst), "failed to acquire reset\n");
-
-	reset_control_deassert(dev->rst);
+		return PTR_ERR(dev->rst);
 
 	ret = i2c_dw_fw_parse_and_configure(dev);
 	if (ret)
-		goto exit_reset;
+		return ret;
 
 	ret = i2c_dw_probe_lock_support(dev);
-	if (ret) {
-		ret = dev_err_probe(device, ret, "failed to probe lock support\n");
-		goto exit_reset;
-	}
+	if (ret)
+		return dev_err_probe(device, ret, "failed to probe lock support\n");
 
 	i2c_dw_configure(dev);
 
 	/* Optional interface clock */
 	dev->pclk = devm_clk_get_optional(device, "pclk");
-	if (IS_ERR(dev->pclk)) {
-		ret = dev_err_probe(device, PTR_ERR(dev->pclk), "failed to acquire pclk\n");
-		goto exit_reset;
-	}
+	if (IS_ERR(dev->pclk))
+		return dev_err_probe(device, PTR_ERR(dev->pclk), "failed to acquire pclk\n");
 
 	dev->clk = devm_clk_get_optional(device, NULL);
-	if (IS_ERR(dev->clk)) {
-		ret = dev_err_probe(device, PTR_ERR(dev->clk), "failed to acquire clock\n");
-		goto exit_reset;
-	}
+	if (IS_ERR(dev->clk))
+		return dev_err_probe(device, PTR_ERR(dev->clk), "failed to acquire clock\n");
 
 	ret = i2c_dw_prepare_clk(dev, true);
 	if (ret)
-		goto exit_reset;
+		return ret;
 
 	if (dev->clk) {
 		struct i2c_timings *t = &dev->timings;
@@ -309,16 +301,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	pm_runtime_enable(device);
 
 	ret = i2c_dw_probe(dev);
-	if (ret)
-		goto exit_probe;
-
-	return ret;
+	if (ret) {
+		dw_i2c_plat_pm_cleanup(dev);
+		i2c_dw_prepare_clk(dev, false);
+	}
 
-exit_probe:
-	dw_i2c_plat_pm_cleanup(dev);
-	i2c_dw_prepare_clk(dev, false);
-exit_reset:
-	reset_control_assert(dev->rst);
 	return ret;
 }
 
@@ -340,8 +327,6 @@ static void dw_i2c_plat_remove(struct platform_device *pdev)
 	i2c_dw_prepare_clk(dev, false);
 
 	i2c_dw_remove_lock_support(dev);
-
-	reset_control_assert(dev->rst);
 }
 
 static const struct of_device_id dw_i2c_of_match[] = {
-- 
2.43.0