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Subject[PATCH v2] hwspinlock: stm32: enable clock at probe
Date
Set the clock during probe and keep its control during suspend / resume
operations.
This fixes an issue when CONFIG_PM is not set and where the clock is
never enabled.

Make use of devm_ functions to simplify the code.

Signed-off-by: Fabien Dessenne <fabien.dessenne@foss.st.com>
---
Changes since v1:
- Call platform_set_drvdata() before pm_runtime_...() calls
---
drivers/hwspinlock/stm32_hwspinlock.c | 58 +++++++++++++++++----------
1 file changed, 37 insertions(+), 21 deletions(-)

diff --git a/drivers/hwspinlock/stm32_hwspinlock.c b/drivers/hwspinlock/stm32_hwspinlock.c
index 3ad0ce0da4d9..5bd11a7fab65 100644
--- a/drivers/hwspinlock/stm32_hwspinlock.c
+++ b/drivers/hwspinlock/stm32_hwspinlock.c
@@ -54,8 +54,23 @@ static const struct hwspinlock_ops stm32_hwspinlock_ops = {
.relax = stm32_hwspinlock_relax,
};

+static void stm32_hwspinlock_disable_clk(void *data)
+{
+ struct platform_device *pdev = data;
+ struct stm32_hwspinlock *hw = platform_get_drvdata(pdev);
+ struct device *dev = &pdev->dev;
+
+ pm_runtime_get_sync(dev);
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+ pm_runtime_put_noidle(dev);
+
+ clk_disable_unprepare(hw->clk);
+}
+
static int stm32_hwspinlock_probe(struct platform_device *pdev)
{
+ struct device *dev = &pdev->dev;
struct stm32_hwspinlock *hw;
void __iomem *io_base;
size_t array_size;
@@ -66,41 +81,43 @@ static int stm32_hwspinlock_probe(struct platform_device *pdev)
return PTR_ERR(io_base);

array_size = STM32_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
- hw = devm_kzalloc(&pdev->dev, sizeof(*hw) + array_size, GFP_KERNEL);
+ hw = devm_kzalloc(dev, sizeof(*hw) + array_size, GFP_KERNEL);
if (!hw)
return -ENOMEM;

- hw->clk = devm_clk_get(&pdev->dev, "hsem");
+ hw->clk = devm_clk_get(dev, "hsem");
if (IS_ERR(hw->clk))
return PTR_ERR(hw->clk);

- for (i = 0; i < STM32_MUTEX_NUM_LOCKS; i++)
- hw->bank.lock[i].priv = io_base + i * sizeof(u32);
+ ret = clk_prepare_enable(hw->clk);
+ if (ret) {
+ dev_err(dev, "Failed to prepare_enable clock\n");
+ return ret;
+ }

platform_set_drvdata(pdev, hw);
- pm_runtime_enable(&pdev->dev);

- ret = hwspin_lock_register(&hw->bank, &pdev->dev, &stm32_hwspinlock_ops,
- 0, STM32_MUTEX_NUM_LOCKS);
+ pm_runtime_get_noresume(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+ pm_runtime_put(dev);

- if (ret)
- pm_runtime_disable(&pdev->dev);
+ ret = devm_add_action_or_reset(dev, stm32_hwspinlock_disable_clk, pdev);
+ if (ret) {
+ dev_err(dev, "Failed to register action\n");
+ return ret;
+ }

- return ret;
-}
+ for (i = 0; i < STM32_MUTEX_NUM_LOCKS; i++)
+ hw->bank.lock[i].priv = io_base + i * sizeof(u32);

-static int stm32_hwspinlock_remove(struct platform_device *pdev)
-{
- struct stm32_hwspinlock *hw = platform_get_drvdata(pdev);
- int ret;
+ ret = devm_hwspin_lock_register(dev, &hw->bank, &stm32_hwspinlock_ops,
+ 0, STM32_MUTEX_NUM_LOCKS);

- ret = hwspin_lock_unregister(&hw->bank);
if (ret)
- dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
-
- pm_runtime_disable(&pdev->dev);
+ dev_err(dev, "Failed to register hwspinlock\n");

- return 0;
+ return ret;
}

static int __maybe_unused stm32_hwspinlock_runtime_suspend(struct device *dev)
@@ -135,7 +152,6 @@ MODULE_DEVICE_TABLE(of, stm32_hwpinlock_ids);

static struct platform_driver stm32_hwspinlock_driver = {
.probe = stm32_hwspinlock_probe,
- .remove = stm32_hwspinlock_remove,
.driver = {
.name = "stm32_hwspinlock",
.of_match_table = stm32_hwpinlock_ids,
--
2.25.1
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