drivers/char/xillybus/xillybus_pcie.c

   1 /*
   2  * linux/drivers/misc/xillybus_pcie.c
   3  *
   4  * Copyright 2011 Xillybus Ltd, http://xillybus.com
   5  *
   6  * Driver for the Xillybus FPGA/host framework using PCI Express.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the smems of the GNU General Public License as published by
  10  * the Free Software Foundation; version 2 of the License.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/pci.h>
  15 #include <linux/pci-aspm.h>
  16 #include <linux/slab.h>
  17 #include "xillybus.h"
  18
  19 MODULE_DESCRIPTION("Xillybus driver for PCIe");
  20 MODULE_AUTHOR("Eli Billauer, Xillybus Ltd.");
  21 MODULE_VERSION("1.06");
  22 MODULE_ALIAS("xillybus_pcie");
  23 MODULE_LICENSE("GPL v2");
  24
  25 #define PCI_DEVICE_ID_XILLYBUS          0xebeb
  26
  27 #define PCI_VENDOR_ID_ALTERA            0x1172
  28 #define PCI_VENDOR_ID_ACTEL             0x11aa
  29 #define PCI_VENDOR_ID_LATTICE           0x1204
  30
  31 static const char xillyname[] = "xillybus_pcie";
  32
  33 static const struct pci_device_id xillyids[] = {
  34         {PCI_DEVICE(PCI_VENDOR_ID_XILINX, PCI_DEVICE_ID_XILLYBUS)},
  35         {PCI_DEVICE(PCI_VENDOR_ID_ALTERA, PCI_DEVICE_ID_XILLYBUS)},
  36         {PCI_DEVICE(PCI_VENDOR_ID_ACTEL, PCI_DEVICE_ID_XILLYBUS)},
  37         {PCI_DEVICE(PCI_VENDOR_ID_LATTICE, PCI_DEVICE_ID_XILLYBUS)},
  38         { /* End: all zeroes */ }
  39 };
  40
  41 static int xilly_pci_direction(int direction)
  42 {
  43         switch (direction) {
  44         case DMA_TO_DEVICE:
  45                 return PCI_DMA_TODEVICE;
  46         case DMA_FROM_DEVICE:
  47                 return PCI_DMA_FROMDEVICE;
  48         default:
  49                 return PCI_DMA_BIDIRECTIONAL;
  50         }
  51 }
  52
  53 static void xilly_dma_sync_single_for_cpu_pci(struct xilly_endpoint *ep,
  54                                               dma_addr_t dma_handle,
  55                                               size_t size,
  56                                               int direction)
  57 {
  58         pci_dma_sync_single_for_cpu(ep->pdev,
  59                                     dma_handle,
  60                                     size,
  61                                     xilly_pci_direction(direction));
  62 }
  63
  64 static void xilly_dma_sync_single_for_device_pci(struct xilly_endpoint *ep,
  65                                                  dma_addr_t dma_handle,
  66                                                  size_t size,
  67                                                  int direction)
  68 {
  69         pci_dma_sync_single_for_device(ep->pdev,
  70                                        dma_handle,
  71                                        size,
  72                                        xilly_pci_direction(direction));
  73 }
  74
  75 static void xilly_pci_unmap(void *ptr)
  76 {
  77         struct xilly_mapping *data = ptr;
  78
  79         pci_unmap_single(data->device, data->dma_addr,
  80                          data->size, data->direction);
  81
  82         kfree(ptr);
  83 }
  84
  85 /*
  86  * Map either through the PCI DMA mapper or the non_PCI one. Behind the
  87  * scenes exactly the same functions are called with the same parameters,
  88  * but that can change.
  89  */
  90
  91 static int xilly_map_single_pci(struct xilly_endpoint *ep,
  92                                 void *ptr,
  93                                 size_t size,
  94                                 int direction,
  95                                 dma_addr_t *ret_dma_handle
  96         )
  97 {
  98         int pci_direction;
  99         dma_addr_t addr;
 100         struct xilly_mapping *this;
 101         int rc;
 102
 103         this = kzalloc(sizeof(*this), GFP_KERNEL);
 104         if (!this)
 105                 return -ENOMEM;
 106
 107         pci_direction = xilly_pci_direction(direction);
 108
 109         addr = pci_map_single(ep->pdev, ptr, size, pci_direction);
 110
 111         if (pci_dma_mapping_error(ep->pdev, addr)) {
 112                 kfree(this);
 113                 return -ENODEV;
 114         }
 115
 116         this->device = ep->pdev;
 117         this->dma_addr = addr;
 118         this->size = size;
 119         this->direction = pci_direction;
 120
 121         *ret_dma_handle = addr;
 122
 123         rc = devm_add_action(ep->dev, xilly_pci_unmap, this);
 124         if (rc) {
 125                 pci_unmap_single(ep->pdev, addr, size, pci_direction);
 126                 kfree(this);
 127                 return rc;
 128         }
 129
 130         return 0;
 131 }
 132
 133 static struct xilly_endpoint_hardware pci_hw = {
 134         .owner = THIS_MODULE,
 135         .hw_sync_sgl_for_cpu = xilly_dma_sync_single_for_cpu_pci,
 136         .hw_sync_sgl_for_device = xilly_dma_sync_single_for_device_pci,
 137         .map_single = xilly_map_single_pci,
 138 };
 139
 140 static int xilly_probe(struct pci_dev *pdev,
 141                        const struct pci_device_id *ent)
 142 {
 143         struct xilly_endpoint *endpoint;
 144         int rc;
 145
 146         endpoint = xillybus_init_endpoint(pdev, &pdev->dev, &pci_hw);
 147
 148         if (!endpoint)
 149                 return -ENOMEM;
 150
 151         pci_set_drvdata(pdev, endpoint);
 152
 153         rc = pcim_enable_device(pdev);
 154         if (rc) {
 155                 dev_err(endpoint->dev,
 156                         "pcim_enable_device() failed. Aborting.\n");
 157                 return rc;
 158         }
 159
 160         /* L0s has caused packet drops. No power saving, thank you. */
 161
 162         pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S);
 163
 164         if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
 165                 dev_err(endpoint->dev,
 166                         "Incorrect BAR configuration. Aborting.\n");
 167                 return -ENODEV;
 168         }
 169
 170         rc = pcim_iomap_regions(pdev, 0x01, xillyname);
 171         if (rc) {
 172                 dev_err(endpoint->dev,
 173                         "pcim_iomap_regions() failed. Aborting.\n");
 174                 return rc;
 175         }
 176
 177         endpoint->registers = pcim_iomap_table(pdev)[0];
 178
 179         pci_set_master(pdev);
 180
 181         /* Set up a single MSI interrupt */
 182         if (pci_enable_msi(pdev)) {
 183                 dev_err(endpoint->dev,
 184                         "Failed to enable MSI interrupts. Aborting.\n");
 185                 return -ENODEV;
 186         }
 187         rc = devm_request_irq(&pdev->dev, pdev->irq, xillybus_isr, 0,
 188                               xillyname, endpoint);
 189         if (rc) {
 190                 dev_err(endpoint->dev,
 191                         "Failed to register MSI handler. Aborting.\n");
 192                 return -ENODEV;
 193         }
 194
 195         /*
 196          * In theory, an attempt to set the DMA mask to 64 and dma_using_dac=1
 197          * is the right thing. But some unclever PCIe drivers report it's OK
 198          * when the hardware drops those 64-bit PCIe packets. So trust
 199          * nobody and use 32 bits DMA addressing in any case.
 200          */
 201
 202         if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
 203                 endpoint->dma_using_dac = 0;
 204         } else {
 205                 dev_err(endpoint->dev, "Failed to set DMA mask. Aborting.\n");
 206                 return -ENODEV;
 207         }
 208
 209         return xillybus_endpoint_discovery(endpoint);
 210 }
 211
 212 static void xilly_remove(struct pci_dev *pdev)
 213 {
 214         struct xilly_endpoint *endpoint = pci_get_drvdata(pdev);
 215
 216         xillybus_endpoint_remove(endpoint);
 217 }
 218
 219 MODULE_DEVICE_TABLE(pci, xillyids);
 220
 221 static struct pci_driver xillybus_driver = {
 222         .name = xillyname,
 223         .id_table = xillyids,
 224         .probe = xilly_probe,
 225         .remove = xilly_remove,
 226 };
 227
 228 module_pci_driver(xillybus_driver);