can: m_can: let m_can_class_allocate_dev() allocate driver specific private data

This patch enhances m_can_class_allocate_dev() to allocate driver specific
private data. The driver's private data struct must contain struct
m_can_classdev as its first member followed by the remaining private data.

Link: https://lore.kernel.org/r/20201212175518.139651-7-mkl@pengutronix.de
Reviewed-by: Sean Nyekjaer <sean@geanix.com>
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 16 insertions, 11 deletions

diff --git a/drivers/net/can/m_can/m_can_pci.c b/drivers/net/can/m_can/m_can_pci.c
index 04010ee0407c..ebfbef25e3f9 100644
--- a/drivers/net/can/m_can/m_can_pci.c
+++ b/drivers/net/can/m_can/m_can_pci.c
@@ -22,26 +22,33 @@
 #define CTL_CSR_INT_CTL_OFFSET		0x508
 
 struct m_can_pci_priv {
+	struct m_can_classdev cdev;
+
 	void __iomem *base;
 };
 
+static inline struct m_can_pci_priv *cdev_to_priv(struct m_can_classdev *cdev)
+{
+	return container_of(cdev, struct m_can_pci_priv, cdev);
+}
+
 static u32 iomap_read_reg(struct m_can_classdev *cdev, int reg)
 {
-	struct m_can_pci_priv *priv = cdev->device_data;
+	struct m_can_pci_priv *priv = cdev_to_priv(cdev);
 
 	return readl(priv->base + reg);
 }
 
 static u32 iomap_read_fifo(struct m_can_classdev *cdev, int offset)
 {
-	struct m_can_pci_priv *priv = cdev->device_data;
+	struct m_can_pci_priv *priv = cdev_to_priv(cdev);
 
 	return readl(priv->base + offset);
 }
 
 static int iomap_write_reg(struct m_can_classdev *cdev, int reg, int val)
 {
-	struct m_can_pci_priv *priv = cdev->device_data;
+	struct m_can_pci_priv *priv = cdev_to_priv(cdev);
 
 	writel(val, priv->base + reg);
 
@@ -50,7 +57,7 @@ static int iomap_write_reg(struct m_can_classdev *cdev, int reg, int val)
 
 static int iomap_write_fifo(struct m_can_classdev *cdev, int offset, int val)
 {
-	struct m_can_pci_priv *priv = cdev->device_data;
+	struct m_can_pci_priv *priv = cdev_to_priv(cdev);
 
 	writel(val, priv->base + offset);
 
@@ -89,21 +96,19 @@ static int m_can_pci_probe(struct pci_dev *pci, const struct pci_device_id *id)
 		return -ENOMEM;
 	}
 
-	priv = devm_kzalloc(&pci->dev, sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
-
-	mcan_class = m_can_class_allocate_dev(&pci->dev);
+	mcan_class = m_can_class_allocate_dev(&pci->dev,
+					      sizeof(struct m_can_pci_priv));
 	if (!mcan_class)
 		return -ENOMEM;
 
+	priv = cdev_to_priv(mcan_class);
+
 	priv->base = base;
 
 	ret = pci_alloc_irq_vectors(pci, 1, 1, PCI_IRQ_ALL_TYPES);
 	if (ret < 0)
 		return ret;
 
-	mcan_class->device_data = priv;
 	mcan_class->dev = &pci->dev;
 	mcan_class->net->irq = pci_irq_vector(pci, 0);
 	mcan_class->pm_clock_support = 1;
@@ -135,7 +140,7 @@ static void m_can_pci_remove(struct pci_dev *pci)
 {
 	struct net_device *dev = pci_get_drvdata(pci);
 	struct m_can_classdev *mcan_class = netdev_priv(dev);
-	struct m_can_pci_priv *priv = mcan_class->device_data;
+	struct m_can_pci_priv *priv = cdev_to_priv(mcan_class);
 
 	pm_runtime_forbid(&pci->dev);
 	pm_runtime_get_noresume(&pci->dev);