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Message-ID: <5445F781.7010804@gmail.com>
Date: Tue, 21 Oct 2014 11:34:49 +0530
From: Varka Bhadram <varkabhadram@...il.com>
To: Ankit Jindal <ankit.jindal@...aro.org>,
linux-kernel@...r.kernel.org
CC: "Hans J. Koch" <hjk@...sjkoch.de>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
patches@....com, linux-arm-kernel@...ts.infradead.org,
Rob Herring <robh+dt@...nel.org>,
Tushar Jagad <tushar.jagad@...aro.org>,
Russell King - ARM Linux <linux@....linux.org.uk>,
devicetree@...r.kernel.org, Guenter Roeck <linux@...ck-us.net>
Subject: Re: [PATCH v3 4/6] uio: Add X-Gene QMTM UIO driver
On 10/21/2014 11:26 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@...aro.org>
> Signed-off-by: Tushar Jagad <tushar.jagad@...aro.org>
(...)
> +
> +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;
> + }
> +
> + csr = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!csr) {
> + ret = -ENODEV;
> + dev_err(&pdev->dev, "No QMTM CSR resource specified\n");
> + goto out_err;
> + }
> +
This error check is not required. *csr* is checked in devm_ioremap_resource().
> + if (!csr->start) {
> + ret = -EINVAL;
> + dev_err(&pdev->dev, "Invalid CSR resource\n");
> + goto out_err;
> + }
> +
> + fabric = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + if (!fabric) {
> + ret = -ENODEV;
> + dev_err(&pdev->dev, "No QMTM Fabric resource specified\n");
> + goto out_err;
> + }
> +
same
> + if (!fabric->start) {
> + ret = -EINVAL;
> + dev_err(&pdev->dev, "Invalid Fabric resource\n");
> + goto out_err;
> + }
> +
> + ret = of_property_read_u32(pdev->dev.of_node, "qpool", &qpool_phandle);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "No qpool resource specified\n");
> + goto out_err;
> + }
> +
> + qpool_node = of_find_node_by_phandle(qpool_phandle);
> + 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_err;
> + }
> +
> + 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_err;
> + }
> +
> + if (!qpool.start) {
> + ret = -EINVAL;
> + dev_err(&pdev->dev, "Invalid qpool resource\n");
> + goto out_err;
> + }
> +
> + ret = of_property_read_u32(pdev->dev.of_node, "num-queues",
> + &num_queues);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "No num-queues resource specified\n");
> + goto out_err;
> + }
> +
> + /* 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_err;
> + }
> +
> + 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_err;
> + }
> +
> + 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_err;
> + }
> +
> + 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;
> +
> + /* enable the clock */
> + clk_prepare_enable(qmtm_dev->qmtm_clk);
> +
> + /* 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_clk;
> + }
> +
> + /* register with uio framework */
> + ret = uio_register_device(&pdev->dev, info);
> + if (ret < 0)
> + goto out_clk;
> +
> + platform_set_drvdata(pdev, qmtm_dev);
> + return 0;
> +
> +out_clk:
> + clk_disable_unprepare(qmtm_dev->qmtm_clk);
> +
> +out_err:
> + return ret;
> +}
>
--
Regards,
Varka Bhadram.
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