arch/powerpc/sysdev/ppc4xx_msi.c

   1 /*
   2  * Adding PCI-E MSI support for PPC4XX SoCs.
   3  *
   4  * Copyright (c) 2010, Applied Micro Circuits Corporation
   5  * Authors:     Tirumala R Marri <tmarri@apm.com>
   6  *              Feng Kan <fkan@apm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 #include <linux/irq.h>
  25 #include <linux/bootmem.h>
  26 #include <linux/pci.h>
  27 #include <linux/msi.h>
  28 #include <linux/of_platform.h>
  29 #include <linux/interrupt.h>
  30 #include <asm/prom.h>
  31 #include <asm/hw_irq.h>
  32 #include <asm/ppc-pci.h>
  33 #include <boot/dcr.h>
  34 #include <asm/dcr-regs.h>
  35 #include <asm/msi_bitmap.h>
  36
  37 #define PEIH_TERMADH    0x00
  38 #define PEIH_TERMADL    0x08
  39 #define PEIH_MSIED      0x10
  40 #define PEIH_MSIMK      0x18
  41 #define PEIH_MSIASS     0x20
  42 #define PEIH_FLUSH0     0x30
  43 #define PEIH_FLUSH1     0x38
  44 #define PEIH_CNTRST     0x48
  45 #define NR_MSI_IRQS     4
  46
  47 struct ppc4xx_msi {
  48         u32 msi_addr_lo;
  49         u32 msi_addr_hi;
  50         void __iomem *msi_regs;
  51         int msi_virqs[NR_MSI_IRQS];
  52         struct msi_bitmap bitmap;
  53         struct device_node *msi_dev;
  54 };
  55
  56 static struct ppc4xx_msi ppc4xx_msi;
  57
  58 static int ppc4xx_msi_init_allocator(struct platform_device *dev,
  59                 struct ppc4xx_msi *msi_data)
  60 {
  61         int err;
  62
  63         err = msi_bitmap_alloc(&msi_data->bitmap, NR_MSI_IRQS,
  64                               dev->dev.of_node);
  65         if (err)
  66                 return err;
  67
  68         err = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
  69         if (err < 0) {
  70                 msi_bitmap_free(&msi_data->bitmap);
  71                 return err;
  72         }
  73
  74         return 0;
  75 }
  76
  77 static int ppc4xx_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
  78 {
  79         int int_no = -ENOMEM;
  80         unsigned int virq;
  81         struct msi_msg msg;
  82         struct msi_desc *entry;
  83         struct ppc4xx_msi *msi_data = &ppc4xx_msi;
  84
  85         list_for_each_entry(entry, &dev->msi_list, list) {
  86                 int_no = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
  87                 if (int_no >= 0)
  88                         break;
  89                 if (int_no < 0) {
  90                         pr_debug("%s: fail allocating msi interrupt\n",
  91                                         __func__);
  92                 }
  93                 virq = irq_of_parse_and_map(msi_data->msi_dev, int_no);
  94                 if (virq == NO_IRQ) {
  95                         dev_err(&dev->dev, "%s: fail mapping irq\n", __func__);
  96                         msi_bitmap_free_hwirqs(&msi_data->bitmap, int_no, 1);
  97                         return -ENOSPC;
  98                 }
  99                 dev_dbg(&dev->dev, "%s: virq = %d\n", __func__, virq);
 100
 101                 /* Setup msi address space */
 102                 msg.address_hi = msi_data->msi_addr_hi;
 103                 msg.address_lo = msi_data->msi_addr_lo;
 104
 105                 irq_set_msi_desc(virq, entry);
 106                 msg.data = int_no;
 107                 write_msi_msg(virq, &msg);
 108         }
 109         return 0;
 110 }
 111
 112 void ppc4xx_teardown_msi_irqs(struct pci_dev *dev)
 113 {
 114         struct msi_desc *entry;
 115         struct ppc4xx_msi *msi_data = &ppc4xx_msi;
 116
 117         dev_dbg(&dev->dev, "PCIE-MSI: tearing down msi irqs\n");
 118
 119         list_for_each_entry(entry, &dev->msi_list, list) {
 120                 if (entry->irq == NO_IRQ)
 121                         continue;
 122                 irq_set_msi_desc(entry->irq, NULL);
 123                 msi_bitmap_free_hwirqs(&msi_data->bitmap,
 124                                 virq_to_hw(entry->irq), 1);
 125                 irq_dispose_mapping(entry->irq);
 126         }
 127 }
 128
 129 static int ppc4xx_msi_check_device(struct pci_dev *pdev, int nvec, int type)
 130 {
 131         dev_dbg(&pdev->dev, "PCIE-MSI:%s called. vec %x type %d\n",
 132                 __func__, nvec, type);
 133         if (type == PCI_CAP_ID_MSIX)
 134                 pr_debug("ppc4xx msi: MSI-X untested, trying anyway.\n");
 135
 136         return 0;
 137 }
 138
 139 static int ppc4xx_setup_pcieh_hw(struct platform_device *dev,
 140                                  struct resource res, struct ppc4xx_msi *msi)
 141 {
 142         const u32 *msi_data;
 143         const u32 *msi_mask;
 144         const u32 *sdr_addr;
 145         dma_addr_t msi_phys;
 146         void *msi_virt;
 147
 148         sdr_addr = of_get_property(dev->dev.of_node, "sdr-base", NULL);
 149         if (!sdr_addr)
 150                 return -1;
 151
 152         SDR0_WRITE(sdr_addr, (u64)res.start >> 32);      /*HIGH addr */
 153         SDR0_WRITE(sdr_addr + 1, res.start & 0xFFFFFFFF); /* Low addr */
 154
 155
 156         msi->msi_dev = of_find_node_by_name(NULL, "ppc4xx-msi");
 157         if (msi->msi_dev)
 158                 return -ENODEV;
 159
 160         msi->msi_regs = of_iomap(msi->msi_dev, 0);
 161         if (!msi->msi_regs) {
 162                 dev_err(&dev->dev, "of_iomap problem failed\n");
 163                 return -ENOMEM;
 164         }
 165         dev_dbg(&dev->dev, "PCIE-MSI: msi register mapped 0x%x 0x%x\n",
 166                 (u32) (msi->msi_regs + PEIH_TERMADH), (u32) (msi->msi_regs));
 167
 168         msi_virt = dma_alloc_coherent(&dev->dev, 64, &msi_phys, GFP_KERNEL);
 169         msi->msi_addr_hi = 0x0;
 170         msi->msi_addr_lo = (u32) msi_phys;
 171         dev_dbg(&dev->dev, "PCIE-MSI: msi address 0x%x\n", msi->msi_addr_lo);
 172
 173         /* Progam the Interrupt handler Termination addr registers */
 174         out_be32(msi->msi_regs + PEIH_TERMADH, msi->msi_addr_hi);
 175         out_be32(msi->msi_regs + PEIH_TERMADL, msi->msi_addr_lo);
 176
 177         msi_data = of_get_property(dev->dev.of_node, "msi-data", NULL);
 178         if (!msi_data)
 179                 return -1;
 180         msi_mask = of_get_property(dev->dev.of_node, "msi-mask", NULL);
 181         if (!msi_mask)
 182                 return -1;
 183         /* Program MSI Expected data and Mask bits */
 184         out_be32(msi->msi_regs + PEIH_MSIED, *msi_data);
 185         out_be32(msi->msi_regs + PEIH_MSIMK, *msi_mask);
 186
 187         return 0;
 188 }
 189
 190 static int ppc4xx_of_msi_remove(struct platform_device *dev)
 191 {
 192         struct ppc4xx_msi *msi = dev->dev.platform_data;
 193         int i;
 194         int virq;
 195
 196         for (i = 0; i < NR_MSI_IRQS; i++) {
 197                 virq = msi->msi_virqs[i];
 198                 if (virq != NO_IRQ)
 199                         irq_dispose_mapping(virq);
 200         }
 201
 202         if (msi->bitmap.bitmap)
 203                 msi_bitmap_free(&msi->bitmap);
 204         iounmap(msi->msi_regs);
 205         of_node_put(msi->msi_dev);
 206         kfree(msi);
 207
 208         return 0;
 209 }
 210
 211 static int __devinit ppc4xx_msi_probe(struct platform_device *dev)
 212 {
 213         struct ppc4xx_msi *msi;
 214         struct resource res;
 215         int err = 0;
 216
 217         msi = &ppc4xx_msi;/*keep the msi data for further use*/
 218
 219         dev_dbg(&dev->dev, "PCIE-MSI: Setting up MSI support...\n");
 220
 221         msi = kzalloc(sizeof(struct ppc4xx_msi), GFP_KERNEL);
 222         if (!msi) {
 223                 dev_err(&dev->dev, "No memory for MSI structure\n");
 224                 return -ENOMEM;
 225         }
 226         dev->dev.platform_data = msi;
 227
 228         /* Get MSI ranges */
 229         err = of_address_to_resource(dev->dev.of_node, 0, &res);
 230         if (err) {
 231                 dev_err(&dev->dev, "%s resource error!\n",
 232                         dev->dev.of_node->full_name);
 233                 goto error_out;
 234         }
 235
 236         if (ppc4xx_setup_pcieh_hw(dev, res, msi))
 237                 goto error_out;
 238
 239         err = ppc4xx_msi_init_allocator(dev, msi);
 240         if (err) {
 241                 dev_err(&dev->dev, "Error allocating MSI bitmap\n");
 242                 goto error_out;
 243         }
 244
 245         ppc_md.setup_msi_irqs = ppc4xx_setup_msi_irqs;
 246         ppc_md.teardown_msi_irqs = ppc4xx_teardown_msi_irqs;
 247         ppc_md.msi_check_device = ppc4xx_msi_check_device;
 248         return err;
 249
 250 error_out:
 251         ppc4xx_of_msi_remove(dev);
 252         return err;
 253 }
 254 static const struct of_device_id ppc4xx_msi_ids[] = {
 255         {
 256                 .compatible = "amcc,ppc4xx-msi",
 257         },
 258         {}
 259 };
 260 static struct platform_driver ppc4xx_msi_driver = {
 261         .probe = ppc4xx_msi_probe,
 262         .remove = ppc4xx_of_msi_remove,
 263         .driver = {
 264                    .name = "ppc4xx-msi",
 265                    .owner = THIS_MODULE,
 266                    .of_match_table = ppc4xx_msi_ids,
 267                    },
 268
 269 };
 270
 271 static __init int ppc4xx_msi_init(void)
 272 {
 273         return platform_driver_register(&ppc4xx_msi_driver);
 274 }
 275
 276 subsys_initcall(ppc4xx_msi_init);