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Message-ID: <20150330080651.GM457@x1>
Date: Mon, 30 Mar 2015 09:06:51 +0100
From: Lee Jones <lee.jones@...aro.org>
To: Holger Dengler <dengler@...utronix.de>
Cc: linux-kernel@...r.kernel.org, Peter Mahler <mahler@...ug.com>,
Juergen Bubeck <bubeck@...ug.com>,
Benedikt Spranger <b.spranger@...utronix.de>,
Samuel Ortiz <sameo@...ux.intel.com>
Subject: Re: [PATCH 02/11] mfd: flexcard: add flexcard core device
On Wed, 25 Mar 2015, Holger Dengler wrote:
> From: Benedikt Spranger <b.spranger@...utronix.de>
>
> The Flexcard PCI BAR0 contain registers for configuration but also
> for informational purpose like error counter, statistical information
> and some timestamps. The read-only mmap of the misc device offers the
> userspace a fast access to these registers.
This code looks like it belongs in drivers/misc.
</review>
> Signed-off-by: Holger Dengler <dengler@...utronix.de>
> Signed-off-by: Benedikt Spranger <b.spranger@...utronix.de>
> cc: Samuel Ortiz <sameo@...ux.intel.com>
> cc: Lee Jones <lee.jones@...aro.org>
> ---
> drivers/mfd/flexcard/core.c | 107 ++++++++++++++++++++++++++++++++++++++++++-
> include/linux/mfd/flexcard.h | 6 +++
> include/uapi/linux/Kbuild | 1 +
> 3 files changed, 112 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mfd/flexcard/core.c b/drivers/mfd/flexcard/core.c
> index 99df3d5..1e7fb0f 100644
> --- a/drivers/mfd/flexcard/core.c
> +++ b/drivers/mfd/flexcard/core.c
> @@ -14,11 +14,16 @@
> #include <linux/module.h>
> #include <linux/init.h>
> #include <linux/flexcard.h>
> +#include <linux/fs.h>
> +#include <linux/kref.h>
> +#include <linux/miscdevice.h>
> #include <linux/pci.h>
> #include <linux/platform_device.h>
> #include <linux/mfd/core.h>
> #include <linux/mfd/flexcard.h>
>
> +static DEFINE_IDA(flexcard_ida);
> +
> static const char drv_name[] = "flexcard";
>
> static int flexcard_tiny_can(struct flexcard_device *priv,
> @@ -104,23 +109,106 @@ static int flexcard_tiny_probe(struct flexcard_device *priv)
> return mfd_add_devices(&pdev->dev, 0, priv->cells, nr, NULL, 0, NULL);
> }
>
> +static int flexcard_misc_open(struct inode *inode, struct file *filp)
> +{
> + struct flexcard_device *priv =
> + container_of(filp->private_data, struct flexcard_device, dev);
> + int ret;
> +
> + filp->private_data = priv;
> + ret = nonseekable_open(inode, filp);
> + if (ret) {
> + dev_err(&priv->pdev->dev, "unable to open file: %d\n", ret);
> + return ret;
> + }
> +
> + kref_get(&priv->ref);
> + return 0;
> +}
> +
> +static void flexcard_dev_release(struct kref *ref)
> +{
> + struct flexcard_device *priv =
> + container_of(ref, struct flexcard_device, ref);
> +
> + kfree(priv);
> + dev_info(&priv->pdev->dev, "misc device release");
> +}
> +
> +static int flexcard_misc_release(struct inode *inode, struct file *filp)
> +{
> + struct flexcard_device *priv = filp->private_data;
> +
> + filp->private_data = NULL;
> + kref_put(&priv->ref, flexcard_dev_release);
> +
> + return 0;
> +}
> +
> +static int flexcard_misc_mmap(struct file *filp, struct vm_area_struct *vma)
> +{
> + struct flexcard_device *priv = filp->private_data;
> + unsigned long offset, vsize, psize, addr;
> +
> + if (vma->vm_flags & (VM_WRITE | VM_EXEC))
> + return -EPERM;
> +
> + offset = vma->vm_pgoff << PAGE_SHIFT;
> + vsize = vma->vm_end - vma->vm_start;
> + psize = pci_resource_len(priv->pdev, 0) - offset;
> + addr = (pci_resource_start(priv->pdev, 0) + offset) >> PAGE_SHIFT;
> +
> + if (vsize > psize) {
> + dev_err(&priv->pdev->dev,
> + "requested mmap mapping too large\n");
> + return -EINVAL;
> + }
> +
> + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
> +
> + return io_remap_pfn_range(vma, vma->vm_start, addr, vsize,
> + vma->vm_page_prot);
> +}
> +
> +static const struct file_operations flexcard_misc_fops = {
> + .owner = THIS_MODULE,
> + .open = flexcard_misc_open,
> + .release = flexcard_misc_release,
> + .mmap = flexcard_misc_mmap,
> + .llseek = no_llseek,
> +};
> +
> static int flexcard_probe(struct pci_dev *pdev,
> const struct pci_device_id *id)
> {
> struct flexcard_device *priv;
> int ret;
>
> - priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> + priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> if (!priv)
> return -ENOMEM;
>
> + ret = ida_simple_get(&flexcard_ida, 0, 0, GFP_KERNEL);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "could not get new Flexcard id:%d\n", ret);
> + goto out_free;
> + }
> +
> + priv->cardnr = ret;
> pci_set_drvdata(pdev, priv);
> priv->pdev = pdev;
> + kref_init(&priv->ref);
> +
> + snprintf(priv->name, sizeof(priv->name), "flexcard%d", priv->cardnr);
> + priv->dev.minor = MISC_DYNAMIC_MINOR;
> + priv->dev.name = priv->name;
> + priv->dev.fops = &flexcard_misc_fops;
> + priv->dev.parent = &pdev->dev;
>
> ret = pci_enable_device(pdev);
> if (ret) {
> dev_err(&pdev->dev, "unable to enable device: %d\n", ret);
> - return ret;
> + goto out_put;
> }
>
> pci_set_master(pdev);
> @@ -143,6 +231,12 @@ static int flexcard_probe(struct pci_dev *pdev,
> goto out_unmap;
> }
>
> + ret = misc_register(&priv->dev);
> + if (ret) {
> + dev_err(&pdev->dev, "unable to register miscdevice: %d\n", ret);
> + goto out_remove;
> + }
> +
> dev_info(&pdev->dev, "HW %02x.%02x.%02x FW %02x.%02x.%02x\n",
> priv->conf->fc_hw_ver.maj, priv->conf->fc_hw_ver.min,
> priv->conf->fc_hw_ver.dev, priv->conf->fc_fw_ver.maj,
> @@ -150,12 +244,18 @@ static int flexcard_probe(struct pci_dev *pdev,
>
> return 0;
>
> +out_remove:
> + mfd_remove_devices(&pdev->dev);
> out_unmap:
> iounmap(priv->conf);
> out_release:
> pci_release_regions(pdev);
> out_disable:
> pci_disable_device(pdev);
> +out_put:
> + ida_simple_remove(&flexcard_ida, priv->cardnr);
> +out_free:
> + kref_put(&priv->ref, flexcard_dev_release);
>
> return ret;
> }
> @@ -164,10 +264,13 @@ static void flexcard_remove(struct pci_dev *pdev)
> {
> struct flexcard_device *priv = pci_get_drvdata(pdev);
>
> + misc_deregister(&priv->dev);
> mfd_remove_devices(&pdev->dev);
> iounmap(priv->conf);
> pci_release_regions(pdev);
> pci_disable_device(pdev);
> + ida_simple_remove(&flexcard_ida, priv->cardnr);
> + kref_put(&priv->ref, flexcard_dev_release);
> }
>
> #define PCI_VENDOR_ID_EBEL 0x1974
> diff --git a/include/linux/mfd/flexcard.h b/include/linux/mfd/flexcard.h
> index 20d0f40..84e155c 100644
> --- a/include/linux/mfd/flexcard.h
> +++ b/include/linux/mfd/flexcard.h
> @@ -19,11 +19,17 @@
> #define FLEXCARD_FR_OFFSET 0x4000
> #define FLEXCARD_FR_SIZE 0x2000
>
> +#define FLEXCARD_MAX_NAME 16
> +
> struct flexcard_device {
> struct pci_dev *pdev;
> struct fc_conf_bar __iomem *conf;
> struct mfd_cell *cells;
> struct resource *res;
> + struct miscdevice dev;
> + struct kref ref;
> + int cardnr;
> + char name[FLEXCARD_MAX_NAME];
> };
>
> enum flexcard_cell_id {
> diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
> index 68ceb97..d5c5002 100644
> --- a/include/uapi/linux/Kbuild
> +++ b/include/uapi/linux/Kbuild
> @@ -127,6 +127,7 @@ header-y += filter.h
> header-y += firewire-cdev.h
> header-y += firewire-constants.h
> header-y += flat.h
> +header-y += flexcard.h
> header-y += fou.h
> header-y += fs.h
> header-y += fsl_hypervisor.h
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
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