drivers/char/xillybus/xillybus_pcie.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/drivers/misc/xillybus_pcie.c
   4  *
   5  * Copyright 2011 Xillybus Ltd, http://xillybus.com
   6  *
   7  * Driver for the Xillybus FPGA/host framework using PCI Express.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/pci.h>
  12 #include <linux/slab.h>
  13 #include "xillybus.h"
  14
  15 MODULE_DESCRIPTION("Xillybus driver for PCIe");
  16 MODULE_AUTHOR("Eli Billauer, Xillybus Ltd.");
  17 MODULE_VERSION("1.06");
  18 MODULE_ALIAS("xillybus_pcie");
  19 MODULE_LICENSE("GPL v2");
  20
  21 #define PCI_DEVICE_ID_XILLYBUS          0xebeb
  22
  23 #define PCI_VENDOR_ID_ACTEL             0x11aa
  24 #define PCI_VENDOR_ID_LATTICE           0x1204
  25
  26 static const char xillyname[] = "xillybus_pcie";
  27
  28 static const struct pci_device_id xillyids[] = {
  29         {PCI_DEVICE(PCI_VENDOR_ID_XILINX, PCI_DEVICE_ID_XILLYBUS)},
  30         {PCI_DEVICE(PCI_VENDOR_ID_ALTERA, PCI_DEVICE_ID_XILLYBUS)},
  31         {PCI_DEVICE(PCI_VENDOR_ID_ACTEL, PCI_DEVICE_ID_XILLYBUS)},
  32         {PCI_DEVICE(PCI_VENDOR_ID_LATTICE, PCI_DEVICE_ID_XILLYBUS)},
  33         { /* End: all zeroes */ }
  34 };
  35
  36 static int xilly_pci_direction(int direction)
  37 {
  38         switch (direction) {
  39         case DMA_TO_DEVICE:
  40                 return PCI_DMA_TODEVICE;
  41         case DMA_FROM_DEVICE:
  42                 return PCI_DMA_FROMDEVICE;
  43         default:
  44                 return PCI_DMA_BIDIRECTIONAL;
  45         }
  46 }
  47
  48 static void xilly_dma_sync_single_for_cpu_pci(struct xilly_endpoint *ep,
  49                                               dma_addr_t dma_handle,
  50                                               size_t size,
  51                                               int direction)
  52 {
  53         pci_dma_sync_single_for_cpu(ep->pdev,
  54                                     dma_handle,
  55                                     size,
  56                                     xilly_pci_direction(direction));
  57 }
  58
  59 static void xilly_dma_sync_single_for_device_pci(struct xilly_endpoint *ep,
  60                                                  dma_addr_t dma_handle,
  61                                                  size_t size,
  62                                                  int direction)
  63 {
  64         pci_dma_sync_single_for_device(ep->pdev,
  65                                        dma_handle,
  66                                        size,
  67                                        xilly_pci_direction(direction));
  68 }
  69
  70 static void xilly_pci_unmap(void *ptr)
  71 {
  72         struct xilly_mapping *data = ptr;
  73
  74         pci_unmap_single(data->device, data->dma_addr,
  75                          data->size, data->direction);
  76
  77         kfree(ptr);
  78 }
  79
  80 /*
  81  * Map either through the PCI DMA mapper or the non_PCI one. Behind the
  82  * scenes exactly the same functions are called with the same parameters,
  83  * but that can change.
  84  */
  85
  86 static int xilly_map_single_pci(struct xilly_endpoint *ep,
  87                                 void *ptr,
  88                                 size_t size,
  89                                 int direction,
  90                                 dma_addr_t *ret_dma_handle
  91         )
  92 {
  93         int pci_direction;
  94         dma_addr_t addr;
  95         struct xilly_mapping *this;
  96
  97         this = kzalloc(sizeof(*this), GFP_KERNEL);
  98         if (!this)
  99                 return -ENOMEM;
 100
 101         pci_direction = xilly_pci_direction(direction);
 102
 103         addr = pci_map_single(ep->pdev, ptr, size, pci_direction);
 104
 105         if (pci_dma_mapping_error(ep->pdev, addr)) {
 106                 kfree(this);
 107                 return -ENODEV;
 108         }
 109
 110         this->device = ep->pdev;
 111         this->dma_addr = addr;
 112         this->size = size;
 113         this->direction = pci_direction;
 114
 115         *ret_dma_handle = addr;
 116
 117         return devm_add_action_or_reset(ep->dev, xilly_pci_unmap, this);
 118 }
 119
 120 static struct xilly_endpoint_hardware pci_hw = {
 121         .owner = THIS_MODULE,
 122         .hw_sync_sgl_for_cpu = xilly_dma_sync_single_for_cpu_pci,
 123         .hw_sync_sgl_for_device = xilly_dma_sync_single_for_device_pci,
 124         .map_single = xilly_map_single_pci,
 125 };
 126
 127 static int xilly_probe(struct pci_dev *pdev,
 128                        const struct pci_device_id *ent)
 129 {
 130         struct xilly_endpoint *endpoint;
 131         int rc;
 132
 133         endpoint = xillybus_init_endpoint(pdev, &pdev->dev, &pci_hw);
 134
 135         if (!endpoint)
 136                 return -ENOMEM;
 137
 138         pci_set_drvdata(pdev, endpoint);
 139
 140         rc = pcim_enable_device(pdev);
 141         if (rc) {
 142                 dev_err(endpoint->dev,
 143                         "pcim_enable_device() failed. Aborting.\n");
 144                 return rc;
 145         }
 146
 147         /* L0s has caused packet drops. No power saving, thank you. */
 148
 149         pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S);
 150
 151         if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
 152                 dev_err(endpoint->dev,
 153                         "Incorrect BAR configuration. Aborting.\n");
 154                 return -ENODEV;
 155         }
 156
 157         rc = pcim_iomap_regions(pdev, 0x01, xillyname);
 158         if (rc) {
 159                 dev_err(endpoint->dev,
 160                         "pcim_iomap_regions() failed. Aborting.\n");
 161                 return rc;
 162         }
 163
 164         endpoint->registers = pcim_iomap_table(pdev)[0];
 165
 166         pci_set_master(pdev);
 167
 168         /* Set up a single MSI interrupt */
 169         if (pci_enable_msi(pdev)) {
 170                 dev_err(endpoint->dev,
 171                         "Failed to enable MSI interrupts. Aborting.\n");
 172                 return -ENODEV;
 173         }
 174         rc = devm_request_irq(&pdev->dev, pdev->irq, xillybus_isr, 0,
 175                               xillyname, endpoint);
 176         if (rc) {
 177                 dev_err(endpoint->dev,
 178                         "Failed to register MSI handler. Aborting.\n");
 179                 return -ENODEV;
 180         }
 181
 182         /*
 183          * Some (old and buggy?) hardware drops 64-bit addressed PCIe packets,
 184          * even when the PCIe driver claims that a 64-bit mask is OK. On the
 185          * other hand, on some architectures, 64-bit addressing is mandatory.
 186          * So go for the 64-bit mask only when failing is the other option.
 187          */
 188
 189         if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
 190                 endpoint->dma_using_dac = 0;
 191         } else if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) {
 192                 endpoint->dma_using_dac = 1;
 193         } else {
 194                 dev_err(endpoint->dev, "Failed to set DMA mask. Aborting.\n");
 195                 return -ENODEV;
 196         }
 197
 198         return xillybus_endpoint_discovery(endpoint);
 199 }
 200
 201 static void xilly_remove(struct pci_dev *pdev)
 202 {
 203         struct xilly_endpoint *endpoint = pci_get_drvdata(pdev);
 204
 205         xillybus_endpoint_remove(endpoint);
 206 }
 207
 208 MODULE_DEVICE_TABLE(pci, xillyids);
 209
 210 static struct pci_driver xillybus_driver = {
 211         .name = xillyname,
 212         .id_table = xillyids,
 213         .probe = xilly_probe,
 214         .remove = xilly_remove,
 215 };
 216
 217 module_pci_driver(xillybus_driver);