Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754879Ab2FKOJs (ORCPT ); Mon, 11 Jun 2012 10:09:48 -0400 Received: from ngcobalt02.manitu.net ([217.11.48.102]:39457 "EHLO ngcobalt02.manitu.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754709Ab2FKOJp (ORCPT ); Mon, 11 Jun 2012 10:09:45 -0400 X-manitu-Original-Sender-IP: 79.214.40.70 X-manitu-Original-Receiver-Name: ngcobalt02.manitu.net Message-ID: <4FD5FC13.8040800@grandegger.com> Date: Mon, 11 Jun 2012 16:09:23 +0200 From: Wolfgang Grandegger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Federico Vaga CC: Marc Kleine-Budde , Giancarlo Asnaghi , Alan Cox , Alessandro Rubini , linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC] c_can_pci: generic module for c_can on PCI References: <4FC135C6.5030206@grandegger.com> <1338816766-7089-1-git-send-email-federico.vaga@gmail.com> <1338816766-7089-2-git-send-email-federico.vaga@gmail.com> In-Reply-To: <1338816766-7089-2-git-send-email-federico.vaga@gmail.com> X-Enigmail-Version: 1.4.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8970 Lines: 315 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. > Signed-off-by: Federico Vaga > Acked-by: Giancarlo Asnaghi > Cc: Alan Cox > --- > 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 don't change unrelated things. It's done that way also in other CAN subdirectories. > config CAN_C_CAN_PLATFORM > tristate "Generic Platform Bus based C_CAN driver" > + depends on CAN_C_CAN > ---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 > + > +config CAN_C_CAN_PCI > + tristate "Generic PCI Bus based C_CAN driver" > + depends on CAN_C_CAN > + ---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 s /Platform/PCI/ ? > + * > + * Copyright (C) 2012 Federico Vaga > + * > + * 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 > +#include > +#include > +#include > +#include > +#include > + > +#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 "); > +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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/