Re: [PATCH RFC] c_can_pci: generic module for c_can on PCI

From: Marc Kleine-Budde
Date: Mon Jun 04 2012 - 10:05:10 EST

Next message: Mark Salter: "build failure in mm/nommu.c"
Previous message: Masami Hiramatsu: "Re: Re: [RFC PATCH -tip 1/9] ftrace: Add pt_regs acceptable tracecallback"
In reply to: Federico Vaga: "[PATCH RFC] c_can_pci: generic module for c_can on PCI"
Next in thread: Alan Cox: "Re: [PATCH RFC] c_can_pci: generic module for c_can on PCI"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On 06/04/2012 03:32 PM, Federico Vaga wrote:
> Signed-off-by: Federico Vaga <federico.vaga@xxxxxxxxx>
> Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@xxxxxx>
> Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>

Please port you driver to the recent c_can changes. Use the c_can branch
of the linux-can-next repo[1] as base for your work. You have to rework
the register access function. Please have a look if there are devm_
variants for the registration/mapping of the pci and clock.

[1] https://gitorious.org/linux-can/linux-can-next

More comments inline. Marc

> ---
> drivers/net/can/c_can/Kconfig | 11 +-
> drivers/net/can/c_can/Makefile | 1 +
> drivers/net/can/c_can/c_can_pci.c | 221 +++++++++++++++++++++++++++++++++++++
> 3 files changed, 230 insertions(+), 3 deletions(-)
> create mode 100644 drivers/net/can/c_can/c_can_pci.c
>
> diff --git a/drivers/net/can/c_can/Kconfig b/drivers/net/can/c_can/Kconfig
> index ffb9773..74ef97d 100644
> --- a/drivers/net/can/c_can/Kconfig
> +++ b/drivers/net/can/c_can/Kconfig
> @@ -2,14 +2,19 @@ menuconfig CAN_C_CAN
> tristate "Bosch C_CAN devices"
> depends on CAN_DEV && HAS_IOMEM
>
> -if CAN_C_CAN

please keep the if CAN_C_CAN...

> -
> config CAN_C_CAN_PLATFORM
> tristate "Generic Platform Bus based C_CAN driver"
> + depends on CAN_C_CAN

...then you don't have to add the depends on here.

> ---help---
> This driver adds support for the C_CAN chips connected to
> the "platform bus" (Linux abstraction for directly to the
> processor attached devices) which can be found on various
> boards from ST Microelectronics (http://www.st.com)
> like the SPEAr1310 and SPEAr320 evaluation boards.
> -endif

... Just move you pci driver inside the if...endif block...
> +
> +config CAN_C_CAN_PCI
> + tristate "Generic PCI Bus based C_CAN driver"
> + depends on CAN_C_CAN

...and remove the depends on CAN_C_CAN. You probably have to add a
depends on PCI.

> + ---help---
> + This driver adds support for the C_CAN chips connected to
> + the PCI bus.
> diff --git a/drivers/net/can/c_can/Makefile b/drivers/net/can/c_can/Makefile
> index 9273f6d..ad1cc84 100644
> --- a/drivers/net/can/c_can/Makefile
> +++ b/drivers/net/can/c_can/Makefile
> @@ -4,5 +4,6 @@
>
> obj-$(CONFIG_CAN_C_CAN) += c_can.o
> obj-$(CONFIG_CAN_C_CAN_PLATFORM) += c_can_platform.o
> +obj-$(CONFIG_CAN_C_CAN_PCI) += c_can_pci.o
>
> ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
> diff --git a/drivers/net/can/c_can/c_can_pci.c b/drivers/net/can/c_can/c_can_pci.c
> new file mode 100644
> index 0000000..b635375
> --- /dev/null
> +++ b/drivers/net/can/c_can/c_can_pci.c
> @@ -0,0 +1,221 @@
> +/*
> + * Platform CAN bus driver for Bosch C_CAN controller
> + *
> + * Copyright (C) 2012 Federico Vaga <federico.vaga@xxxxxxxxx>
> + *
^^^ double space :)

> + * 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 */
^^^^^^^^^^^^
use the enum you defined above.

> + 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);
> +}
> +
> +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)
^^^

looks fishy

> + 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
> + */
> + 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);
> + if (!priv->priv)
dito
> + 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) = {
^^^^

static?

> + C_CAN_ID(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_CAN,
> + c_can_sta2x11),
> + {},
> +};
> +static struct pci_driver sta2x11_pci_driver = {
> + .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 <federico.vaga@xxxxxxxxx>");
> +MODULE_LICENSE("GPL V2");

IIRC, the correct case is "GPL v2"

> +MODULE_DESCRIPTION("PCI CAN bus driver for Bosch C_CAN controller");
> +MODULE_DEVICE_TABLE(pci, c_can_pci_tbl);

--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |

Attachment: signature.asc
Description: OpenPGP digital signature

Next message: Mark Salter: "build failure in mm/nommu.c"
Previous message: Masami Hiramatsu: "Re: Re: [RFC PATCH -tip 1/9] ftrace: Add pt_regs acceptable tracecallback"
In reply to: Federico Vaga: "[PATCH RFC] c_can_pci: generic module for c_can on PCI"
Next in thread: Alan Cox: "Re: [PATCH RFC] c_can_pci: generic module for c_can on PCI"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]