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_ACTEL             0x11aa
  28 #define PCI_VENDOR_ID_LATTICE           0x1204
  29
  30 static const char xillyname[] = "xillybus_pcie";
  31
  32 static const struct pci_device_id xillyids[] = {
  33         {PCI_DEVICE(PCI_VENDOR_ID_XILINX, PCI_DEVICE_ID_XILLYBUS)},
  34         {PCI_DEVICE(PCI_VENDOR_ID_ALTERA, PCI_DEVICE_ID_XILLYBUS)},
  35         {PCI_DEVICE(PCI_VENDOR_ID_ACTEL, PCI_DEVICE_ID_XILLYBUS)},
  36         {PCI_DEVICE(PCI_VENDOR_ID_LATTICE, PCI_DEVICE_ID_XILLYBUS)},
  37         { /* End: all zeroes */ }
  38 };
  39
  40 static int xilly_pci_direction(int direction)
  41 {
  42         switch (direction) {
  43         case DMA_TO_DEVICE:
  44                 return PCI_DMA_TODEVICE;
  45         case DMA_FROM_DEVICE:
  46                 return PCI_DMA_FROMDEVICE;
  47         default:
  48                 return PCI_DMA_BIDIRECTIONAL;
  49         }
  50 }
  51
  52 static void xilly_dma_sync_single_for_cpu_pci(struct xilly_endpoint *ep,
  53                                               dma_addr_t dma_handle,
  54                                               size_t size,
  55                                               int direction)
  56 {
  57         pci_dma_sync_single_for_cpu(ep->pdev,
  58                                     dma_handle,
  59                                     size,
  60                                     xilly_pci_direction(direction));
  61 }
  62
  63 static void xilly_dma_sync_single_for_device_pci(struct xilly_endpoint *ep,
  64                                                  dma_addr_t dma_handle,
  65                                                  size_t size,
  66                                                  int direction)
  67 {
  68         pci_dma_sync_single_for_device(ep->pdev,
  69                                        dma_handle,
  70                                        size,
  71                                        xilly_pci_direction(direction));
  72 }
  73
  74 static void xilly_pci_unmap(void *ptr)
  75 {
  76         struct xilly_mapping *data = ptr;
  77
  78         pci_unmap_single(data->device, data->dma_addr,
  79                          data->size, data->direction);
  80
  81         kfree(ptr);
  82 }
  83
  84 /*
  85  * Map either through the PCI DMA mapper or the non_PCI one. Behind the
  86  * scenes exactly the same functions are called with the same parameters,
  87  * but that can change.
  88  */
  89
  90 static int xilly_map_single_pci(struct xilly_endpoint *ep,
  91                                 void *ptr,
  92                                 size_t size,
  93                                 int direction,
  94                                 dma_addr_t *ret_dma_handle
  95         )
  96 {
  97         int pci_direction;
  98         dma_addr_t addr;
  99         struct xilly_mapping *this;
 100
 101         this = kzalloc(sizeof(*this), GFP_KERNEL);
 102         if (!this)
 103                 return -ENOMEM;
 104
 105         pci_direction = xilly_pci_direction(direction);
 106
 107         addr = pci_map_single(ep->pdev, ptr, size, pci_direction);
 108
 109         if (pci_dma_mapping_error(ep->pdev, addr)) {
 110                 kfree(this);
 111                 return -ENODEV;
 112         }
 113
 114         this->device = ep->pdev;
 115         this->dma_addr = addr;
 116         this->size = size;
 117         this->direction = pci_direction;
 118
 119         *ret_dma_handle = addr;
 120
 121         return devm_add_action_or_reset(ep->dev, xilly_pci_unmap, this);
 122 }
 123
 124 static struct xilly_endpoint_hardware pci_hw = {
 125         .owner = THIS_MODULE,
 126         .hw_sync_sgl_for_cpu = xilly_dma_sync_single_for_cpu_pci,
 127         .hw_sync_sgl_for_device = xilly_dma_sync_single_for_device_pci,
 128         .map_single = xilly_map_single_pci,
 129 };
 130
 131 static int xilly_probe(struct pci_dev *pdev,
 132                        const struct pci_device_id *ent)
 133 {
 134         struct xilly_endpoint *endpoint;
 135         int rc;
 136
 137         endpoint = xillybus_init_endpoint(pdev, &pdev->dev, &pci_hw);
 138
 139         if (!endpoint)
 140                 return -ENOMEM;
 141
 142         pci_set_drvdata(pdev, endpoint);
 143
 144         rc = pcim_enable_device(pdev);
 145         if (rc) {
 146                 dev_err(endpoint->dev,
 147                         "pcim_enable_device() failed. Aborting.\n");
 148                 return rc;
 149         }
 150
 151         /* L0s has caused packet drops. No power saving, thank you. */
 152
 153         pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S);
 154
 155         if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
 156                 dev_err(endpoint->dev,
 157                         "Incorrect BAR configuration. Aborting.\n");
 158                 return -ENODEV;
 159         }
 160
 161         rc = pcim_iomap_regions(pdev, 0x01, xillyname);
 162         if (rc) {
 163                 dev_err(endpoint->dev,
 164                         "pcim_iomap_regions() failed. Aborting.\n");
 165                 return rc;
 166         }
 167
 168         endpoint->registers = pcim_iomap_table(pdev)[0];
 169
 170         pci_set_master(pdev);
 171
 172         /* Set up a single MSI interrupt */
 173         if (pci_enable_msi(pdev)) {
 174                 dev_err(endpoint->dev,
 175                         "Failed to enable MSI interrupts. Aborting.\n");
 176                 return -ENODEV;
 177         }
 178         rc = devm_request_irq(&pdev->dev, pdev->irq, xillybus_isr, 0,
 179                               xillyname, endpoint);
 180         if (rc) {
 181                 dev_err(endpoint->dev,
 182                         "Failed to register MSI handler. Aborting.\n");
 183                 return -ENODEV;
 184         }
 185
 186         /*
 187          * Some (old and buggy?) hardware drops 64-bit addressed PCIe packets,
 188          * even when the PCIe driver claims that a 64-bit mask is OK. On the
 189          * other hand, on some architectures, 64-bit addressing is mandatory.
 190          * So go for the 64-bit mask only when failing is the other option.
 191          */
 192
 193         if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
 194                 endpoint->dma_using_dac = 0;
 195         } else if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) {
 196                 endpoint->dma_using_dac = 1;
 197         } else {
 198                 dev_err(endpoint->dev, "Failed to set DMA mask. Aborting.\n");
 199                 return -ENODEV;
 200         }
 201
 202         return xillybus_endpoint_discovery(endpoint);
 203 }
 204
 205 static void xilly_remove(struct pci_dev *pdev)
 206 {
 207         struct xilly_endpoint *endpoint = pci_get_drvdata(pdev);
 208
 209         xillybus_endpoint_remove(endpoint);
 210 }
 211
 212 MODULE_DEVICE_TABLE(pci, xillyids);
 213
 214 static struct pci_driver xillybus_driver = {
 215         .name = xillyname,
 216         .id_table = xillyids,
 217         .probe = xilly_probe,
 218         .remove = xilly_remove,
 219 };
 220
 221 module_pci_driver(xillybus_driver);