On Fri, Jan 11, 2019 at 07:33:41PM +0100, Gustavo Pimentel wrote:
> Synopsys eDMA IP is normally distributed along with Synopsys PCIe
> EndPoint IP (depends of the use and licensing agreement).
>
> This IP requires some basic configurations, such as:
> - eDMA registers BAR
> - eDMA registers offset
> - eDMA registers size
> - eDMA linked list memory BAR
> - eDMA linked list memory offset
> - eDMA linked list memory sze
> - eDMA data memory BAR
> - eDMA data memory offset
> - eDMA data memory size
> - eDMA version
> - eDMA mode
> - IRQs available for eDMA
>
> As a working example, PCIe glue-logic will attach to a Synopsys PCIe
> EndPoint IP prototype kit (Vendor ID = 0x16c3, Device ID = 0xedda),
> which has built-in an eDMA IP with this default configuration:
> - eDMA registers BAR = 0
> - eDMA registers offset = 0x00001000 (4 Kbytes)
> - eDMA registers size = 0x00002000 (8 Kbytes)
> - eDMA linked list memory BAR = 2
> - eDMA linked list memory offset = 0x00000000 (0 Kbytes)
> - eDMA linked list memory size = 0x00800000 (8 Mbytes)
> - eDMA data memory BAR = 2
> - eDMA data memory offset = 0x00800000 (8 Mbytes)
> - eDMA data memory size = 0x03800000 (56 Mbytes)
> - eDMA version = 0
> - eDMA mode = EDMA_MODE_UNROLL
> - IRQs = 1
>
> This driver can be compile as built-in or external module in kernel.
>
> To enable this driver just select DW_EDMA_PCIE option in kernel
> configuration, however it requires and selects automatically DW_EDMA
> option too.
>
> Changes:
> RFC v1->RFC v2:
Changes go after '--- ' line.
> - Replace comments // (C99 style) by /**/
> - Merge two pcim_iomap_regions() calls into just one call
> - Remove pci_try_set_mwi() call
> - Replace some dev_info() by dev_dbg() to reduce *noise*
> - Remove pci_name(pdev) call after being call dw_edma_remove()
> - Remove all power management support
> - Fix the headers of the .c and .h files according to the most recent
> convention
> - Fix errors and checks pointed out by checkpatch with --strict option
> - Replace patch small description tag from dma by dmaengine
> RFC v2->RFC v3:
> - Fix printk variable of phys_addr_t type
> - Fix missing variable initialization (chan->configured)
> - Change linked list size to 512 Kbytes
> - Add data memory information
> - Add register size information
> - Add comments or improve existing ones
> - Add possibility to work with multiple IRQs feature
> - Replace MSI and MSI-X enable condition by pci_dev_msi_enabled()
> - Replace code to acquire MSI(-X) address and data by
> get_cached_msi_msg()
> +enum dw_edma_pcie_bar {
> + BAR_0,
> + BAR_1,
> + BAR_2,
> + BAR_3,
> + BAR_4,
> + BAR_5
> +};
pci-epf.h has this.
Why duplicate?
What else is being duplicated from PCI core?
> +static bool disable_msix;
> +module_param(disable_msix, bool, 0644);
> +MODULE_PARM_DESC(disable_msix, "Disable MSI-X interrupts");
Why?!
We are no allow new module parameters without very strong arguments.
> +
> +static int dw_edma_pcie_probe(struct pci_dev *pdev,
> + const struct pci_device_id *pid)
> +{
> + const struct dw_edma_pcie_data *pdata = (void *)pid->driver_data;
> + struct device *dev = &pdev->dev;
> + struct dw_edma_chip *chip;
> + struct dw_edma *dw;
> + unsigned int irq_flags = PCI_IRQ_MSI;
> + int err, nr_irqs, i;
> +
> + if (!pdata) {
> + dev_err(dev, "%s missing data structure\n", pci_name(pdev));
> + return -EFAULT;
> + }
Useless check.
> +
> + /* Enable PCI device */
> + err = pcim_enable_device(pdev);
> + if (err) {
> + dev_err(dev, "%s enabling device failed\n", pci_name(pdev));
> + return err;
> + }
> +
> + /* Mapping PCI BAR regions */
> + err = pcim_iomap_regions(pdev, BIT(pdata->rg_bar) |
> + BIT(pdata->ll_bar) |
> + BIT(pdata->dt_bar),
> + pci_name(pdev));
> + if (err) {
> + dev_err(dev, "%s eDMA BAR I/O remapping failed\n",
> + pci_name(pdev));
Isn't it pci_err() ?
Same comment for the rest similar cases above and below.
> + return err;
> + }
> +
> + pci_set_master(pdev);
> +
> + nr_irqs = pci_alloc_irq_vectors(pdev, 1, pdata->irqs_cnt, irq_flags);
> + if (nr_irqs < 1) {
> + dev_err(dev, "%s failed to alloc IRQ vector (Number of IRQs=%u)\n",
> + pci_name(pdev), nr_irqs);
> + return -EPERM;
> + }
> +
> + /* Data structure initialization */
> + chip->dw = dw;
> + chip->dev = dev;
> + chip->id = pdev->devfn;
> + chip->irq = pdev->irq;
> +
> + if (!pcim_iomap_table(pdev))
> + return -EACCES;
Never happen condition. Thus useless.
> + dev_info(dev, "DesignWare eDMA PCIe driver loaded completely\n");
Useless.
> +}
> +
> +static void dw_edma_pcie_remove(struct pci_dev *pdev)
> +{
> + struct dw_edma_chip *chip = pci_get_drvdata(pdev);
> + struct device *dev = &pdev->dev;
> + int err;
> +
> + /* Stopping eDMA driver */
> + err = dw_edma_remove(chip);
> + if (err)
> + dev_warn(dev, "can't remove device properly: %d\n", err);
> +
> + /* Freeing IRQs */
> + pci_free_irq_vectors(pdev);
> +
> + dev_info(dev, "DesignWare eDMA PCIe driver unloaded completely\n");
Ditto.
> +}
> +MODULE_DEVICE_TABLE(pci, dw_edma_pcie_id_table);
> +
> +static struct pci_driver dw_edma_pcie_driver = {
> + .name = "dw-edma-pcie",
> + .id_table = dw_edma_pcie_id_table,
> + .probe = dw_edma_pcie_probe,
> + .remove = dw_edma_pcie_remove,
Power management?
> +};
--
With Best Regards,
Andy Shevchenko
