Re: [RESEND PATCH V1] can: sja1000: f81601: add Fintek F81601 support

From: Marc Kleine-Budde
Date: Fri Jul 19 2019 - 09:53:59 EST

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On 6/11/19 3:47 AM, 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>
> ---
> drivers/net/can/sja1000/Kconfig | 8 ++
> drivers/net/can/sja1000/Makefile | 1 +
> drivers/net/can/sja1000/f81601.c | 223 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 232 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..1578bb837aaf
> --- /dev/null
> +++ b/drivers/net/can/sja1000/f81601.c
> @@ -0,0 +1,223 @@
> +// 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 {
> + int channels; /* detected channels count */

Where is this variable used? Why does it have to live inside this struct.

> + void __iomem *addr;
> + spinlock_t lock; /* for access mem io */

This description is not in sync with the source. Use use this spin lock
only for write access, not to access the iomem in general. Please update
the code or the description.

> + 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 < F81601_PCI_MAX_CHAN; i++) {

Usee ARRAY_SIZE instead of F81601_PCI_MAX_CHAN.

> + 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;
> + int err, i;
> + 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->channels = 0;
> + 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;

nitpick: pleas use only 2 tabs to indent here.

> +
> + 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;
> + }
> +
> + /* Detect available channels */
> + for (i = 0; i < F81601_PCI_MAX_CHAN; i++) {
> + /* read CAN2_HW_EN strap pin */
> + pci_read_config_byte(pdev, F81601_TRAP_REG, &tmp);

Why do you read this inside the loop? Read it outside and adjust the end
of the for loop instead.

> + if (i == 1 && !(tmp & F81601_CAN2_HAS_EN))
> + break;
> +
> + dev = alloc_sja1000dev(0);
> + if (!dev) {
> + err = -ENOMEM;
> + goto failure_cleanup;
> + }
> +
> + card->net_dev[i] = dev;
> + dev->irq = pdev->irq;
> +
> + 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;
> +
> + /* Register SJA1000 device */
> + err = register_sja1000dev(dev);
> + if (err) {
> + dev_err(&pdev->dev,
> + "%s: Registering device failed: %x\n", __func__,
> + err);
> + goto failure_cleanup;

If this fails you still call a unregister_sja1000dev() in
f81601_pci_del_card()

> + }
> +
> + card->channels++;
> +
> + dev_info(&pdev->dev, "Channel #%d, %s at 0x%p, irq %d\n", i,
> + dev->name, priv->reg_base, dev->irq);
> + }
> +
> + if (!card->channels) {
> + err = -ENODEV;
> + goto failure_cleanup;
> + }
> +
> + 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);
>

Marc

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