[PATCH v2] thermal/drivers/sun8i: Fix some error handling paths in sun8i_ths_probe()

From: Christophe JAILLET
Date: Sun May 14 2023 - 14:46:32 EST


Should an error occur after calling sun8i_ths_resource_init() in the probe
function, some resources need to be released, as already done in the
.remove() function.

Switch to the devm_clk_get_enabled() helper and add a new devm_action to
turn sun8i_ths_resource_init() into a fully managed function.

Move the place where reset_control_deassert() is called so that the
recommended order of reset release/clock enable steps is kept.
A64 manual states that:

3.3.6.4. Gating and reset

Make sure that the reset signal has been released before the release of
module clock gating;

This fixes the issue and removes some LoC at the same time.

Fixes: dccc5c3b6f30 ("thermal/drivers/sun8i: Add thermal driver for H6/H5/H3/A64/A83T/R40")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
Changes in v2:
- move reset_control_deassert() next to devm_reset_control_get()

v1: https://lore.kernel.org/all/26f9e3bb3fcd0c12ea24a44c75b7960da993b68b.1684077651.git.christophe.jaillet@xxxxxxxxxx/
---
drivers/thermal/sun8i_thermal.c | 55 +++++++++++----------------------
1 file changed, 18 insertions(+), 37 deletions(-)

diff --git a/drivers/thermal/sun8i_thermal.c b/drivers/thermal/sun8i_thermal.c
index 793ddce72132..d4d241686c81 100644
--- a/drivers/thermal/sun8i_thermal.c
+++ b/drivers/thermal/sun8i_thermal.c
@@ -319,6 +319,11 @@ static int sun8i_ths_calibrate(struct ths_device *tmdev)
return ret;
}

+static void sun8i_ths_reset_control_assert(void *data)
+{
+ reset_control_assert(data);
+}
+
static int sun8i_ths_resource_init(struct ths_device *tmdev)
{
struct device *dev = tmdev->dev;
@@ -339,47 +344,35 @@ static int sun8i_ths_resource_init(struct ths_device *tmdev)
if (IS_ERR(tmdev->reset))
return PTR_ERR(tmdev->reset);

- tmdev->bus_clk = devm_clk_get(&pdev->dev, "bus");
+ ret = reset_control_deassert(tmdev->reset);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(dev, sun8i_ths_reset_control_assert,
+ tmdev->reset);
+ if (ret)
+ return ret;
+
+ tmdev->bus_clk = devm_clk_get_enabled(&pdev->dev, "bus");
if (IS_ERR(tmdev->bus_clk))
return PTR_ERR(tmdev->bus_clk);
}

if (tmdev->chip->has_mod_clk) {
- tmdev->mod_clk = devm_clk_get(&pdev->dev, "mod");
+ tmdev->mod_clk = devm_clk_get_enabled(&pdev->dev, "mod");
if (IS_ERR(tmdev->mod_clk))
return PTR_ERR(tmdev->mod_clk);
}

- ret = reset_control_deassert(tmdev->reset);
- if (ret)
- return ret;
-
- ret = clk_prepare_enable(tmdev->bus_clk);
- if (ret)
- goto assert_reset;
-
ret = clk_set_rate(tmdev->mod_clk, 24000000);
if (ret)
- goto bus_disable;
-
- ret = clk_prepare_enable(tmdev->mod_clk);
- if (ret)
- goto bus_disable;
+ return ret;

ret = sun8i_ths_calibrate(tmdev);
if (ret)
- goto mod_disable;
+ return ret;

return 0;
-
-mod_disable:
- clk_disable_unprepare(tmdev->mod_clk);
-bus_disable:
- clk_disable_unprepare(tmdev->bus_clk);
-assert_reset:
- reset_control_assert(tmdev->reset);
-
- return ret;
}

static int sun8i_h3_thermal_init(struct ths_device *tmdev)
@@ -530,17 +523,6 @@ static int sun8i_ths_probe(struct platform_device *pdev)
return 0;
}

-static int sun8i_ths_remove(struct platform_device *pdev)
-{
- struct ths_device *tmdev = platform_get_drvdata(pdev);
-
- clk_disable_unprepare(tmdev->mod_clk);
- clk_disable_unprepare(tmdev->bus_clk);
- reset_control_assert(tmdev->reset);
-
- return 0;
-}
-
static const struct ths_thermal_chip sun8i_a83t_ths = {
.sensor_num = 3,
.scale = 705,
@@ -642,7 +624,6 @@ MODULE_DEVICE_TABLE(of, of_ths_match);

static struct platform_driver ths_driver = {
.probe = sun8i_ths_probe,
- .remove = sun8i_ths_remove,
.driver = {
.name = "sun8i-thermal",
.of_match_table = of_ths_match,
--
2.34.1