[PATCH] mfd: intel_quark_i2c_gpio: manage the fixed-rate clock

[Myeonghun Pak <mhun512@gmail.com>]

The I2C clock is allocated by clk_register_fixed_rate(), but cleanup uses
clk_unregister(), leaving the fixed-rate provider allocation behind.

Manage the provider with devm_clk_hw_register_fixed_rate() and its lookup
with devm_clk_hw_register_clkdev(). Managed resources release the lookup
before the provider, after the MFD children have been removed.

Remove the manual clock cleanup and the private structure that only
stored the clock and lookup pointers.

This issue was identified during our ongoing static-analysis research while
reviewing kernel code.

Fixes: 60ae5b9f5cdd ("mfd: intel_quark_i2c_gpio: Add Intel Quark X1000 I2C-GPIO MFD Driver")
Assisted-by: OpenAI:GPT-5.6
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
---
 drivers/mfd/intel_quark_i2c_gpio.c | 52 +++++---------------------------------
 1 file changed, 6 insertions(+), 46 deletions(-)

diff --git a/drivers/mfd/intel_quark_i2c_gpio.c b/drivers/mfd/intel_quark_i2c_gpio.c
index 9b9c76bd067b8198553013af70c9123e33fb9041..443a1a0cf7778d400b40e0c75439e3c7235f8ec5 100644
--- a/drivers/mfd/intel_quark_i2c_gpio.c
+++ b/drivers/mfd/intel_quark_i2c_gpio.c
@@ -35,11 +35,6 @@
 /* The Quark I2C controller source clock */
 #define INTEL_QUARK_I2C_CLK_HZ	33000000
 
-struct intel_quark_mfd {
-	struct clk		*i2c_clk;
-	struct clk_lookup	*i2c_clk_lookup;
-};
-
 static const struct property_entry intel_quark_i2c_controller_standard_properties[] = {
 	PROPERTY_ENTRY_U32("clock-frequency", I2C_MAX_STANDARD_MODE_FREQ),
 	{ }
@@ -160,37 +155,12 @@ MODULE_DEVICE_TABLE(pci, intel_quark_mfd_ids);
 
 static int intel_quark_register_i2c_clk(struct device *dev)
 {
-	struct intel_quark_mfd *quark_mfd = dev_get_drvdata(dev);
-	struct clk *i2c_clk;
-
-	i2c_clk = clk_register_fixed_rate(dev,
-					  INTEL_QUARK_I2C_CONTROLLER_CLK, NULL,
-					  0, INTEL_QUARK_I2C_CLK_HZ);
-	if (IS_ERR(i2c_clk))
-		return PTR_ERR(i2c_clk);
-
-	quark_mfd->i2c_clk = i2c_clk;
-	quark_mfd->i2c_clk_lookup = clkdev_create(i2c_clk, NULL,
-						INTEL_QUARK_I2C_CONTROLLER_CLK);
-
-	if (!quark_mfd->i2c_clk_lookup) {
-		clk_unregister(quark_mfd->i2c_clk);
-		dev_err(dev, "Fixed clk register failed\n");
-		return -ENOMEM;
-	}
-
-	return 0;
-}
-
-static void intel_quark_unregister_i2c_clk(struct device *dev)
-{
-	struct intel_quark_mfd *quark_mfd = dev_get_drvdata(dev);
-
-	if (!quark_mfd->i2c_clk_lookup)
-		return;
+	struct clk_hw *hw;
 
-	clkdev_drop(quark_mfd->i2c_clk_lookup);
-	clk_unregister(quark_mfd->i2c_clk);
+	hw = devm_clk_hw_register_fixed_rate(dev, INTEL_QUARK_I2C_CONTROLLER_CLK,
+					     NULL, 0, INTEL_QUARK_I2C_CLK_HZ);
+	return devm_clk_hw_register_clkdev(dev, hw, NULL,
+					 INTEL_QUARK_I2C_CONTROLLER_CLK);
 }
 
 static int intel_quark_i2c_setup(struct pci_dev *pdev)
@@ -238,19 +208,12 @@ static int intel_quark_gpio_setup(struct pci_dev *pdev)
 static int intel_quark_mfd_probe(struct pci_dev *pdev,
 				 const struct pci_device_id *id)
 {
-	struct intel_quark_mfd *quark_mfd;
 	int ret;
 
 	ret = pcim_enable_device(pdev);
 	if (ret)
 		return ret;
 
-	quark_mfd = devm_kzalloc(&pdev->dev, sizeof(*quark_mfd), GFP_KERNEL);
-	if (!quark_mfd)
-		return -ENOMEM;
-
-	dev_set_drvdata(&pdev->dev, quark_mfd);
-
 	ret = intel_quark_register_i2c_clk(&pdev->dev);
 	if (ret)
 		return ret;
@@ -260,7 +223,7 @@ static int intel_quark_mfd_probe(struct pci_dev *pdev,
 	/* This driver only requires 1 IRQ vector */
 	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
 	if (ret < 0)
-		goto err_unregister_i2c_clk;
+		return ret;
 
 	ret = intel_quark_i2c_setup(pdev);
 	if (ret)
@@ -282,8 +245,6 @@ static int intel_quark_mfd_probe(struct pci_dev *pdev,
 	software_node_unregister_node_group(intel_quark_gpio_node_group);
 err_free_irq_vectors:
 	pci_free_irq_vectors(pdev);
-err_unregister_i2c_clk:
-	intel_quark_unregister_i2c_clk(&pdev->dev);
 	return ret;
 }
 
@@ -292,7 +253,6 @@ static void intel_quark_mfd_remove(struct pci_dev *pdev)
 	mfd_remove_devices(&pdev->dev);
 	software_node_unregister_node_group(intel_quark_gpio_node_group);
 	pci_free_irq_vectors(pdev);
-	intel_quark_unregister_i2c_clk(&pdev->dev);
 }
 
 static struct pci_driver intel_quark_mfd_driver = {
-- 
2.53.0