Re: [PATCH v2 4/6] drivers: uio: Add X-Gene QMTM UIO driver

[Ankit Jindal]

On 30 September 2014 11:35, Varka Bhadram <varkabhadram@xxxxxxxxx> wrote:
> I think *drivers* is not required in the commit message...
>
>
> On 09/30/2014 09:56 AM, Ankit Jindal wrote:
>>
>> The Applied Micro X-Gene SOC has on-chip QMTM (Queue manager
>> and Traffic manager) which is hardware based Queue or Ring
>> manager. This QMTM device can be used in conjunction with
>> other devices such as DMA Engine, Ethernet, Security Engine,
>> etc to assign work based on queues or rings.
>>
>> This patch allows user space access to X-Gene QMTM device.
>>
>> Signed-off-by: Ankit Jindal <ankit.jindal@xxxxxxxxxx>
>> Signed-off-by: Tushar Jagad <tushar.jagad@xxxxxxxxxx>
>> ---
>>   drivers/uio/Kconfig          |    8 ++
>>   drivers/uio/Makefile         |    1 +
>>   drivers/uio/uio_xgene_qmtm.c |  278
>> ++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 287 insertions(+)
>>   create mode 100644 drivers/uio/uio_xgene_qmtm.c
>>
>> diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
>> index 5a90914..76b1858 100644
>> --- a/drivers/uio/Kconfig
>> +++ b/drivers/uio/Kconfig
>> @@ -135,4 +135,12 @@ config UIO_MF624
>>           If you compile this as a module, it will be called uio_mf624.
>>   +config UIO_XGENE_QMTM
>> +       tristate "Applied Micro X-Gene QMTM driver"
>> +       depends on OF
>> +       help
>> +         Userspace I/O interface for the X-Gene QMTM. The userspace part
>> of
>> +         this driver will be available for download from the Applied
>> Micro
>> +         web site (http://www.apm.com/).
>> +
>>   endif
>> diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
>> index d3218bd..633eaa0 100644
>> --- a/drivers/uio/Makefile
>> +++ b/drivers/uio/Makefile
>> @@ -8,3 +8,4 @@ obj-$(CONFIG_UIO_PCI_GENERIC)   += uio_pci_generic.o
>>   obj-$(CONFIG_UIO_NETX)        += uio_netx.o
>>   obj-$(CONFIG_UIO_PRUSS)         += uio_pruss.o
>>   obj-$(CONFIG_UIO_MF624)         += uio_mf624.o
>> +obj-$(CONFIG_UIO_XGENE_QMTM)   += uio_xgene_qmtm.o
>> diff --git a/drivers/uio/uio_xgene_qmtm.c b/drivers/uio/uio_xgene_qmtm.c
>> new file mode 100644
>> index 0000000..36d9000
>> --- /dev/null
>> +++ b/drivers/uio/uio_xgene_qmtm.c
>> @@ -0,0 +1,278 @@
>> +/*
>> + * X-Gene Queue Manager Traffic Manager (QMTM) UIO driver
>> (uio_xgene_qmtm)
>> + *
>> + * This driver exports QMTM CSRs, Fabric and memory for queues to
>> user-space
>> + *
>> + * Copyright (C) 2014 Applied Micro - http://www.apm.com/
>> + * Copyright (C) 2014 Linaro Ltd.
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License as
>> + * published by the Free Software Foundation version 2.
>> + *
>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
>> + * kind, whether express or implied; without even the implied warranty
>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/device.h>
>> +#include <linux/delay.h>
>> +#include <linux/module.h>
>> +#include <linux/moduleparam.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/uio_driver.h>
>> +#include <linux/io.h>
>> +#include <linux/clk.h>
>> +#include <linux/slab.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/of_address.h>
>> +
>
>
> Headers in alphabetical order...?
>
> #include <linux/clk.h>
> #include <linux/device.h>
>
> ...
>
>
>> +#define DRV_NAME "qmtm_uio"
>> +#define DRV_VERSION "1.0"
>> +
>> +#define QMTM_CFG_MEM_RAM_SHUTDOWN      0x0000d070
>> +
>> +#define QMTM_DEFAULT_QSIZE             65536
>> +
>> +struct uio_qmtm_dev {
>> +       struct uio_info *info;
>> +       struct clk *qmtm_clk;
>> +};
>> +
>> +/* QMTM CSR read/write routine */
>> +static inline void qmtm_csr_write(struct uio_qmtm_dev *qmtm_dev, u32
>> offset,
>> +               u32 data)
>> +{
>> +       void __iomem *addr = qmtm_dev->info->mem[0].internal_addr;
>> +
>> +       writel(data, addr + offset);
>> +}
>> +
>> +static inline u32 qmtm_csr_read(struct uio_qmtm_dev *qmtm_dev, u32
>> offset)
>> +{
>> +       void __iomem *addr = qmtm_dev->info->mem[0].internal_addr;
>> +
>> +       return readl(addr + offset);
>> +}
>> +
>> +static int qmtm_reset(struct uio_qmtm_dev *qmtm_dev)
>> +{
>> +       u32 val;
>> +       int wait = 1000;
>> +
>> +       /* reset the internal memory of the device */
>> +       qmtm_csr_write(qmtm_dev, QMTM_CFG_MEM_RAM_SHUTDOWN, 0);
>> +
>> +       /* check whether device internal memory is out of reset or not */
>> +       while (1) {
>> +               val = qmtm_csr_read(qmtm_dev, QMTM_CFG_MEM_RAM_SHUTDOWN);
>> +
>> +               if (val != 0xffffffff)
>> +                       return 0;
>> +
>> +               if (!wait--)
>> +                       return -EBUSY;
>> +
>> +               udelay(1);
>> +       }
>> +}
>> +
>> +static void qmtm_cleanup(struct platform_device *pdev,
>> +               struct uio_qmtm_dev *qmtm_dev)
>> +{
>> +       struct uio_info *info = qmtm_dev->info;
>> +
>> +       uio_unregister_device(info);
>> +
>> +       clk_disable_unprepare(qmtm_dev->qmtm_clk);
>> +}
>> +
>> +static int qmtm_probe(struct platform_device *pdev)
>> +{
>> +       struct uio_info *info;
>> +       struct uio_qmtm_dev *qmtm_dev;
>> +       struct resource *csr;
>> +       struct resource *fabric;
>> +       struct resource qpool;
>> +       unsigned int num_queues;
>> +       unsigned int devid;
>> +       phandle qpool_phandle;
>> +       struct device_node *qpool_node;
>> +       int ret;
>> +
>> +       qmtm_dev = devm_kzalloc(&pdev->dev, sizeof(struct uio_qmtm_dev),
>> +                               GFP_KERNEL);
>> +       if (!qmtm_dev)
>> +               return -ENOMEM;
>> +
>> +       qmtm_dev->info = devm_kzalloc(&pdev->dev, sizeof(*info),
>> GFP_KERNEL);
>> +       if (!qmtm_dev->info)
>> +               return -ENOMEM;
>> +
>> +       /* Power on qmtm in case its not done as part of boot-loader */
>> +       qmtm_dev->qmtm_clk = devm_clk_get(&pdev->dev, NULL);
>> +       if (IS_ERR(qmtm_dev->qmtm_clk)) {
>> +               dev_err(&pdev->dev, "Failed to get clock\n");
>> +               ret = PTR_ERR(qmtm_dev->qmtm_clk);
>> +               return ret;
>> +       } else {
>> +               clk_prepare_enable(qmtm_dev->qmtm_clk);
>> +       }
>> +
>> +       csr = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +       if (!csr) {
>> +               ret = -ENODEV;
>> +               dev_err(&pdev->dev, "No QMTM CSR resource specified\n");
>> +               goto out_free;
>> +       }
>> +
>> +       if (!csr->start) {
>> +               ret = -EINVAL;
>> +               dev_err(&pdev->dev, "Invalid CSR resource\n");
>> +               goto out_free;
>> +       }
>> +
>> +       fabric = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>> +       if (!fabric) {
>> +               ret = -ENODEV;
>> +               dev_err(&pdev->dev, "No QMTM Fabric resource
>> specified\n");
>> +               goto out_free;
>> +       }
>> +
>> +       if (!fabric->start) {
>> +               ret = -EINVAL;
>> +               dev_err(&pdev->dev, "Invalid Fabric resource\n");
>> +               goto out_free;
>> +       }
>> +
>> +       ret = of_property_read_u32(pdev->dev.of_node, "qpool",
>> &qpool_phandle);
>> +
>
>
> unnecessary one line space..
>
>> +       if (ret < 0) {
>> +               dev_err(&pdev->dev, "No qpool resource specified\n");
>> +               goto out_free;
>> +       }
>> +
>> +       qpool_node = of_find_node_by_phandle(qpool_phandle);
>> +
>
>
> unnecessary one line space..
>
>> +       if (IS_ERR_OR_NULL(qpool_node)) {
>> +               ret = PTR_ERR(qpool_node);
>> +               dev_err(&pdev->dev, "Failed to get node by phandle\n");
>> +               goto out_free;
>> +       }
>> +
>> +       ret = of_address_to_resource(qpool_node, 0, &qpool);
>> +
>> +       of_node_put(qpool_node);
>> +
>> +       if (ret < 0) {
>> +               dev_err(&pdev->dev, "Failed to get qpool resource from
>> node\n");
>> +               goto out_free;
>> +       }
>> +
>> +       if (!qpool.start) {
>> +               ret = -EINVAL;
>> +               dev_err(&pdev->dev, "Invalid qpool resource\n");
>> +               goto out_free;
>> +       }
>> +
>> +       ret = of_property_read_u32(pdev->dev.of_node, "num-queues",
>> +                       &num_queues);
>> +
>
>
> unnecessary one line space..
>
>
>> +       if (ret < 0) {
>> +               dev_err(&pdev->dev, "No num-queues resource specified\n");
>> +               goto out_free;
>> +       }
>> +
>> +       /* check whether sufficient memory is provided for the given
>> queues */
>> +       if (!((num_queues * QMTM_DEFAULT_QSIZE) <= resource_size(&qpool)))
>> {
>> +               ret = -ENOSPC;
>> +               dev_err(&pdev->dev, "Insufficient Qpool for the given
>> queues\n");
>> +               goto out_free;
>> +       }
>> +
>> +       ret = of_property_read_u32(pdev->dev.of_node, "devid", &devid);
>> +       if (ret < 0) {
>> +               dev_err(&pdev->dev, "No devid resource specified\n");
>> +               goto out_free;
>> +       }
>> +
>> +       info = qmtm_dev->info;
>> +       info->mem[0].name = "csr";
>> +       info->mem[0].addr = csr->start;
>> +       info->mem[0].size = resource_size(csr);
>> +       info->mem[0].memtype = UIO_MEM_PHYS;
>> +       info->mem[0].internal_addr = devm_ioremap_resource(&pdev->dev,
>> csr);
>> +
>> +       if (IS_ERR(info->mem[0].internal_addr)) {
>> +               ret = PTR_ERR(info->mem[0].internal_addr);
>> +               dev_err(&pdev->dev, "Failed to ioremap CSR region\n");
>> +               goto out_free;
>> +       }
>> +
>> +       info->mem[1].name = "fabric";
>> +       info->mem[1].addr = fabric->start;
>> +       info->mem[1].size = resource_size(fabric);
>> +       info->mem[1].memtype = UIO_MEM_PHYS;
>> +
>> +       info->mem[2].name = "qpool";
>> +       info->mem[2].addr = qpool.start;
>> +       info->mem[2].size = resource_size(&qpool);
>> +       info->mem[2].memtype = UIO_MEM_PHYS_CACHE;
>> +
>> +       info->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "qmtm%d",
>> devid);
>> +       info->version = DRV_VERSION;
>> +
>> +       info->priv = qmtm_dev;
>> +
>> +       /* get the qmtm out of reset */
>> +       ret = qmtm_reset(qmtm_dev);
>> +       if (ret < 0) {
>> +               dev_err(&pdev->dev, "Failed to reset QMTM\n");
>> +               goto out_free;
>> +       }
>> +
>> +       /* register with uio framework */
>> +       ret = uio_register_device(&pdev->dev, info);
>> +       if (ret < 0)
>> +               goto out_free;
>> +
>> +       platform_set_drvdata(pdev, qmtm_dev);
>> +       return 0;
>> +
>> +out_free:
>> +       qmtm_cleanup(pdev, qmtm_dev);
>> +       return ret;
>> +}
>> +
>> +static int qmtm_remove(struct platform_device *pdev)
>> +{
>> +       struct uio_qmtm_dev *qmtm_dev = platform_get_drvdata(pdev);
>> +
>> +       qmtm_cleanup(pdev, qmtm_dev);
>> +       return 0;
>> +}
>> +
>> +static struct of_device_id qmtm_match[] = {
>> +       {.compatible = "apm,xgene-qmtm",},
>> +       {},
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, qmtm_match);
>> +
>> +static struct platform_driver qmtm_driver = {
>> +       .driver = {
>> +               .name = DRV_NAME,
>> +               .owner = THIS_MODULE,
>
>
> Its not required. It will be updated by *module_platform_driver()*
>
>
>> +               .of_match_table = qmtm_match,
>> +       },
>> +       .probe = qmtm_probe,
>> +       .remove = qmtm_remove,
>> +};
>> +
>> +module_platform_driver(qmtm_driver);
>
>
>
I will address all of your comments in next revision.

-Ankit
> --
> Regards,
> Varka Bhadram.
>
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