Hi Federico,

here comes my late review. Mark and others have already commented and I
will focus on further improvements...

On 06/04/2012 03:32 PM, Federico Vaga wrote:

A few more words would be nice here.

Please don't change unrelated things. It's done that way also in other
CAN subdirectories.

s /Platform/PCI/ ?

+ *
+ * Copyright (C) 2012 Federico Vaga [off-list ref]
+  *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/clk.h>
+#include <linux/pci.h>
+#include <linux/can/dev.h>
+
+#include "c_can.h"
+
+enum c_can_pci_reg_align {
+	C_CAN_REG_ALIGN_16,
+	C_CAN_REG_ALIGN_32,
+};
+
+struct c_can_pci_data {
+	unsigned int reg_align;	/* Set the register alignment in the memory */

Should be "enum c_can_pci_reg_align" here.

+	unsigned int freq;	/* Set the frequency if clk is not usable */
+};
+
+/*
+ * 16-bit c_can registers can be arranged differently in the memory
+ * architecture of different implementations. For example: 16-bit
+ * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
+ * Handle the same by providing a common read/write interface.
+ */
+static u16 c_can_pci_read_reg_aligned_to_16bit(struct c_can_priv *priv,
+						void *reg)
+{
+	return readw(reg);
+}
+
+static void c_can_pci_write_reg_aligned_to_16bit(struct c_can_priv *priv,
+						void *reg, u16 val)
+{
+	writew(val, reg);
+}
+
+static u16 c_can_pci_read_reg_aligned_to_32bit(struct c_can_priv *priv,
+						void *reg)
+{
+	return readw(reg + (long)reg - (long)priv->regs);
+}
+
+static void c_can_pci_write_reg_aligned_to_32bit(struct c_can_priv *priv,
+						void *reg, u16 val)
+{
+	writew(val, reg + (long)reg - (long)priv->regs);
+}

This will look better with the new register access methods.

+static int __devinit c_can_pci_probe(struct pci_dev *pdev,
+				     const struct pci_device_id *ent)
+{
+	struct c_can_pci_data *c_can_pci_data = (void *)ent->driver_data;
+	struct c_can_priv *priv;
+	struct net_device *dev;
+	void __iomem *addr;
+	struct clk *clk;
+	int ret;
+
+	ret = pci_enable_device(pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "pci_enable_device FAILED\n");
+		goto out;
+	}
+
+	ret = pci_request_regions(pdev, KBUILD_MODNAME);
+	if (ret) {
+		dev_err(&pdev->dev, "pci_request_regions FAILED\n");
+		goto out_disable_device;
+	}
+
+	pci_set_master(pdev);
+	pci_enable_msi(pdev);
+
+	addr = pci_iomap(pdev, 0, pci_resource_len(pdev, 0));
+	if (!addr) {
+		dev_err(&pdev->dev,
+			"device has no PCI memory resources, "
+			"failing adapter\n");
+		ret = -ENOMEM;
+		goto out_release_regions;
+	}
+
+	/* allocate the c_can device */
+	dev = alloc_c_can_dev();
+	if (!dev) {
+		ret = -ENOMEM;
+		goto out_iounmap;
+	}
+
+	priv = netdev_priv(dev);
+	pci_set_drvdata(pdev, dev);
+	SET_NETDEV_DEV(dev, &pdev->dev);
+
+	dev->irq = pdev->irq;
+	priv->regs = addr;
+
+	if (!c_can_pci_data->freq) {
+		/* get the appropriate clk */
+		clk = clk_get(&pdev->dev, NULL);
+		if (IS_ERR(clk)) {
+			dev_err(&pdev->dev, "no clock defined\n");
+			ret = -ENODEV;
+			goto out_free_c_can;
+		}
+		priv->can.clock.freq = clk_get_rate(clk);
+		priv->priv = clk;
+	} else {
+		priv->can.clock.freq = c_can_pci_data->freq;
+		priv->priv = NULL;
+	}
+
+	switch (c_can_pci_data->reg_align) {
+	case C_CAN_REG_ALIGN_32:
+		priv->read_reg = c_can_pci_read_reg_aligned_to_32bit;
+		priv->write_reg = c_can_pci_write_reg_aligned_to_32bit;
+		break;
+	case C_CAN_REG_ALIGN_16:
+	default:
+		priv->read_reg = c_can_pci_read_reg_aligned_to_16bit;
+		priv->write_reg = c_can_pci_write_reg_aligned_to_16bit;
+		break;
+	}
+
+	ret = register_c_can_dev(dev);
+	if (ret) {
+		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
+			KBUILD_MODNAME, ret);
+		goto out_free_clock;
+	}
+
+	dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
+		 KBUILD_MODNAME, priv->regs, dev->irq);
+
+	return 0;
+
+out_free_clock:
+	if (!priv->priv)
+		clk_put(priv->priv);
+out_free_c_can:
+	pci_set_drvdata(pdev, NULL);
+	free_c_can_dev(dev);
+out_iounmap:
+	pci_iounmap(pdev, addr);
+out_release_regions:
+	pci_disable_msi(pdev);
+	pci_clear_master(pdev);
+	pci_release_regions(pdev);
+out_disable_device:
+	/*
+	 * do not call pci_disable_device on sta2x11 because it
+	 * break all other Bus masters on this EP
+	 */

Puh!

+	if(pdev->vendor == PCI_VENDOR_ID_STMICRO &&
+	   pdev->device == PCI_DEVICE_ID_STMICRO_CAN)
+		goto out;
+	pci_disable_device(pdev);
+out:
+	return ret;
+}
+
+static void __devexit c_can_pci_remove(struct pci_dev *pdev)
+{
+	struct net_device *dev = pci_get_drvdata(pdev);
+	struct c_can_priv *priv = netdev_priv(dev);
+
+	pci_set_drvdata(pdev, NULL);
+	free_c_can_dev(dev);

Should be moved a few line down.

+	if (!priv->priv)
+		clk_put(priv->priv);
+	pci_iounmap(pdev, priv->regs);
+	pci_disable_msi(pdev);
+	pci_clear_master(pdev);
+	pci_release_regions(pdev);
+	/*
+	 * do not call pci_disable_device on sta2x11 because it
+	 * break all other Bus masters on this EP
+	 */
+	if(pdev->vendor == PCI_VENDOR_ID_STMICRO &&
+	   pdev->device == PCI_DEVICE_ID_STMICRO_CAN)
+		return;
+	pci_disable_device(pdev);
+}
+
+static struct c_can_pci_data c_can_sta2x11= {
+	.reg_align = C_CAN_REG_ALIGN_32,
+	.freq = 52000000, /* 52 Mhz */
+};
+
+#define C_CAN_ID(_vend, _dev, _driverdata) {		\
+	PCI_DEVICE(_vend, _dev),			\
+	.driver_data = (unsigned long)&_driverdata,	\
+}
+DEFINE_PCI_DEVICE_TABLE(c_can_pci_tbl) = {
+	C_CAN_ID(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_CAN,
+		 c_can_sta2x11),
+	{},
+};
+static struct pci_driver sta2x11_pci_driver = {

Why do you not use a generic name here?

+	.name = KBUILD_MODNAME,
+	.id_table = c_can_pci_tbl,
+	.probe = c_can_pci_probe,
+	.remove = __devexit_p(c_can_pci_remove),
+};
+
+module_pci_driver(sta2x11_pci_driver);
+
+MODULE_AUTHOR("Federico Vaga [off-list ref]");
+MODULE_LICENSE("GPL V2");
+MODULE_DESCRIPTION("PCI CAN bus driver for Bosch C_CAN controller");
+MODULE_DEVICE_TABLE(pci, c_can_pci_tbl);

Thanks for your contribution.

Wolfgang.