hwspinlock: stm32: enable clock at probe

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>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211011135836.1045437-1-fabien.dessenne@foss.st.com

diff --git a/drivers/hwspinlock/stm32_hwspinlock.c b/drivers/hwspinlock/stm32_hwspinlock.c
index 3ad0ce0..5bd11a7 100644 (file)
--- 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,