Re: [PATCH V2 1/1] can: sja1000: f81601: add Fintek F81601 support

[Saeed Mahameed]

On Mon, 2019-07-22 at 14:22 +0800, Ji-Ze Hong (Peter Hong) wrote:
> This patch add support for Fintek PCIE to 2 CAN controller support
> 
> Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@xxxxxxxxx
> >
> ---
> Changelog:
> v2:
> 	1: Fix comment on the spinlock with write access.
> 	2: Use ARRAY_SIZE instead of F81601_PCI_MAX_CHAN.
> 	3: Check the strap pin outside the loop.
> 	4: Fix the cleanup issue in f81601_pci_add_card().
> 	5: Remove unused "channels" in struct f81601_pci_card.
> 
>  drivers/net/can/sja1000/Kconfig  |   8 ++
>  drivers/net/can/sja1000/Makefile |   1 +
>  drivers/net/can/sja1000/f81601.c | 215
> +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 224 insertions(+)
>  create mode 100644 drivers/net/can/sja1000/f81601.c
> 
> diff --git a/drivers/net/can/sja1000/Kconfig
> b/drivers/net/can/sja1000/Kconfig
> index f6dc89927ece..8588323c5138 100644
> --- a/drivers/net/can/sja1000/Kconfig
> +++ b/drivers/net/can/sja1000/Kconfig
> @@ -101,4 +101,12 @@ config CAN_TSCAN1
>  	  IRQ numbers are read from jumpers JP4 and JP5,
>  	  SJA1000 IO base addresses are chosen heuristically (first
> that works).
>  
> +config CAN_F81601
> +	tristate "Fintek F81601 PCIE to 2 CAN Controller"
> +	depends on PCI
> +	help
> +	  This driver adds support for Fintek F81601 PCIE to 2 CAN
> Controller.
> +	  It had internal 24MHz clock source, but it can be changed by
> +	  manufacturer. We can use modinfo to get usage for parameters.
> +	  Visit http://www.fintek.com.tw to get more information.
>  endif
> diff --git a/drivers/net/can/sja1000/Makefile
> b/drivers/net/can/sja1000/Makefile
> index 9253aaf9e739..6f6268543bd9 100644
> --- a/drivers/net/can/sja1000/Makefile
> +++ b/drivers/net/can/sja1000/Makefile
> @@ -13,3 +13,4 @@ obj-$(CONFIG_CAN_PEAK_PCMCIA) += peak_pcmcia.o
>  obj-$(CONFIG_CAN_PEAK_PCI) += peak_pci.o
>  obj-$(CONFIG_CAN_PLX_PCI) += plx_pci.o
>  obj-$(CONFIG_CAN_TSCAN1) += tscan1.o
> +obj-$(CONFIG_CAN_F81601) += f81601.o
> diff --git a/drivers/net/can/sja1000/f81601.c
> b/drivers/net/can/sja1000/f81601.c
> new file mode 100644
> index 000000000000..3c378de8764d
> --- /dev/null
> +++ b/drivers/net/can/sja1000/f81601.c
> @@ -0,0 +1,215 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Fintek F81601 PCIE to 2 CAN controller driver
> + *
> + * Copyright (C) 2019 Peter Hong <peter_hong@xxxxxxxxxxxxx>
> + * Copyright (C) 2019 Linux Foundation
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/netdevice.h>
> +#include <linux/delay.h>
> +#include <linux/slab.h>
> +#include <linux/pci.h>
> +#include <linux/can/dev.h>
> +#include <linux/io.h>
> +#include <linux/version.h>
> +
> +#include "sja1000.h"
> +
> +#define F81601_PCI_MAX_CHAN		2
> +
> +#define F81601_DECODE_REG		0x209
> +#define F81601_IO_MODE			BIT(7)
> +#define F81601_MEM_MODE			BIT(6)
> +#define F81601_CFG_MODE			BIT(5)
> +#define F81601_CAN2_INTERNAL_CLK	BIT(3)
> +#define F81601_CAN1_INTERNAL_CLK	BIT(2)
> +#define F81601_CAN2_EN			BIT(1)
> +#define F81601_CAN1_EN			BIT(0)
> +
> +#define F81601_TRAP_REG			0x20a
> +#define F81601_CAN2_HAS_EN		BIT(4)
> +
> +struct f81601_pci_card {
> +	void __iomem *addr;
> +	spinlock_t lock;	/* use this spin lock only for write access
> */
> +	struct pci_dev *dev;
> +	struct net_device *net_dev[F81601_PCI_MAX_CHAN];
> +};
> +
> +static const struct pci_device_id f81601_pci_tbl[] = {
> +	{ PCI_DEVICE(0x1c29, 0x1703) },
> +	{},
> +};
> +
> +MODULE_DEVICE_TABLE(pci, f81601_pci_tbl);
> +
> +static bool internal_clk = 1;
> +module_param(internal_clk, bool, 0444);
> +MODULE_PARM_DESC(internal_clk, "Use internal clock, default 1
> (24MHz)");
> +
> +static unsigned int external_clk;
> +module_param(external_clk, uint, 0444);
> +MODULE_PARM_DESC(external_clk, "External Clock, must spec when
> internal_clk = 0");
> +
> +static u8 f81601_pci_read_reg(const struct sja1000_priv *priv, int
> port)
> +{
> +	return readb(priv->reg_base + port);
> +}
> +
> +static void f81601_pci_write_reg(const struct sja1000_priv *priv,
> int port,
> +				 u8 val)
> +{
> +	struct f81601_pci_card *card = priv->priv;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&card->lock, flags);
> +	writeb(val, priv->reg_base + port);
> +	readb(priv->reg_base);
> +	spin_unlock_irqrestore(&card->lock, flags);
> +}
> +
> +static void f81601_pci_del_card(struct pci_dev *pdev)
> +{
> +	struct f81601_pci_card *card = pci_get_drvdata(pdev);
> +	struct net_device *dev;
> +	int i = 0;
> +
> +	for (i = 0; i < ARRAY_SIZE(card->net_dev); i++) {
> +		dev = card->net_dev[i];
> +		if (!dev)
> +			continue;
> +
> +		dev_info(&pdev->dev, "%s: Removing %s\n", __func__,
> dev->name);
> +
> +		unregister_sja1000dev(dev);
> +		free_sja1000dev(dev);
> +	}
> +
> +	pcim_iounmap(pdev, card->addr);
> +}
> +
> +/* Probe F81601 based device for the SJA1000 chips and register each
> + * available CAN channel to SJA1000 Socket-CAN subsystem.
> + */
> +static int f81601_pci_add_card(struct pci_dev *pdev,
> +			       const struct pci_device_id *ent)
> +{
> +	struct sja1000_priv *priv;
> +	struct net_device *dev;
> +	struct f81601_pci_card *card;

nit, reverse xmas tree.

> +	int err, i, count;
> +	u8 tmp;
> +
> +	if (pcim_enable_device(pdev) < 0) {
> +		dev_err(&pdev->dev, "Failed to enable PCI device\n");
> +		return -ENODEV;
> +	}
> +
> +	dev_info(&pdev->dev, "Detected card at slot #%i\n",
> +		 PCI_SLOT(pdev->devfn));
> +
> +	card = devm_kzalloc(&pdev->dev, sizeof(*card), GFP_KERNEL);
> +	if (!card)
> +		return -ENOMEM;
> +
> +	card->dev = pdev;
> +	spin_lock_init(&card->lock);
> +
> +	pci_set_drvdata(pdev, card);
> +
> +	tmp = F81601_IO_MODE | F81601_MEM_MODE | F81601_CFG_MODE |
> +		F81601_CAN2_EN | F81601_CAN1_EN;
> +
> +	if (internal_clk) {
> +		tmp |= F81601_CAN2_INTERNAL_CLK |
> F81601_CAN1_INTERNAL_CLK;
> +
> +		dev_info(&pdev->dev,
> +			 "F81601 running with internal clock:
> 24Mhz\n");
> +	} else {
> +		dev_info(&pdev->dev,
> +			 "F81601 running with external clock: %dMhz\n",
> +			 external_clk / 1000000);
> +	}
> +
> +	pci_write_config_byte(pdev, F81601_DECODE_REG, tmp);
> +
> +	card->addr = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
> +
> +	if (!card->addr) {
> +		err = -ENOMEM;
> +		dev_err(&pdev->dev, "%s: Failed to remap BAR\n",
> __func__);
> +		goto failure_cleanup;
> +	}
> +
> +	/* read CAN2_HW_EN strap pin to detect how many CANBUS do we
> have */
> +	count = ARRAY_SIZE(card->net_dev);
> +	pci_read_config_byte(pdev, F81601_TRAP_REG, &tmp);
> +	if (!(tmp & F81601_CAN2_HAS_EN))
> +		count = 1;
> +
> +	/* Detect available channels */
> +	for (i = 0; i < count; i++) {
> +		dev = alloc_sja1000dev(0);
> +		if (!dev) {
> +			err = -ENOMEM;
> +			goto failure_cleanup;
> +		}
> +

don't you need to rollback and cleanup/unregister previously allocated
devs ?

> +		priv = netdev_priv(dev);
> +		priv->priv = card;
> +		priv->irq_flags = IRQF_SHARED;
> +		priv->reg_base = card->addr + 0x80 * i;
> +		priv->read_reg = f81601_pci_read_reg;
> +		priv->write_reg = f81601_pci_write_reg;
> +
> +		if (internal_clk)
> +			priv->can.clock.freq = 24000000 / 2;
> +		else
> +			priv->can.clock.freq = external_clk / 2;
> +
> +		priv->ocr = OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL;
> +		priv->cdr = CDR_CBP;
> +
> +		SET_NETDEV_DEV(dev, &pdev->dev);
> +		dev->dev_id = i;
> +		dev->irq = pdev->irq;
> +
> +		/* Register SJA1000 device */
> +		err = register_sja1000dev(dev);
> +		if (err) {
> +			dev_err(&pdev->dev,
> +				"%s: Registering device failed: %x\n",
> __func__,
> +				err);
> +			free_sja1000dev(dev);
> +			goto failure_cleanup;
> +		}
> +
> +		card->net_dev[i] = dev;
> +		dev_info(&pdev->dev, "Channel #%d, %s at 0x%p, irq
> %d\n", i,
> +			 dev->name, priv->reg_base, dev->irq);
> +	}
> +
> +	return 0;
> +
> +failure_cleanup:
> +	dev_err(&pdev->dev, "%s: failed: %d. Cleaning Up.\n", __func__,
> err);
> +	f81601_pci_del_card(pdev);
> +
> +	return err;
> +}
> +
> +static struct pci_driver f81601_pci_driver = {
> +	.name =		"f81601",
> +	.id_table =	f81601_pci_tbl,
> +	.probe =	f81601_pci_add_card,
> +	.remove =	f81601_pci_del_card,
> +};
> +
> +MODULE_DESCRIPTION("Fintek F81601 PCIE to 2 CANBUS adaptor driver");
> +MODULE_AUTHOR("Peter Hong <peter_hong@xxxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> +
> +module_pci_driver(f81601_pci_driver);