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 <linux/export.h>
  31 #include <asm/prom.h>
  32 #include <asm/hw_irq.h>
  33 #include <asm/ppc-pci.h>
  34 #include <boot/dcr.h>
  35 #include <asm/dcr-regs.h>
  36 #include <asm/msi_bitmap.h>
  37
  38 #define PEIH_TERMADH    0x00
  39 #define PEIH_TERMADL    0x08
  40 #define PEIH_MSIED      0x10
  41 #define PEIH_MSIMK      0x18
  42 #define PEIH_MSIASS     0x20
  43 #define PEIH_FLUSH0     0x30
  44 #define PEIH_FLUSH1     0x38
  45 #define PEIH_CNTRST     0x48
  46 #define NR_MSI_IRQS     4
  47
  48 struct ppc4xx_msi {
  49         u32 msi_addr_lo;
  50         u32 msi_addr_hi;
  51         void __iomem *msi_regs;
  52         int msi_virqs[NR_MSI_IRQS];
  53         struct msi_bitmap bitmap;
  54         struct device_node *msi_dev;
  55 };
  56
  57 static struct ppc4xx_msi ppc4xx_msi;
  58
  59 static int ppc4xx_msi_init_allocator(struct platform_device *dev,
  60                 struct ppc4xx_msi *msi_data)
  61 {
  62         int err;
  63
  64         err = msi_bitmap_alloc(&msi_data->bitmap, NR_MSI_IRQS,
  65                               dev->dev.of_node);
  66         if (err)
  67                 return err;
  68
  69         err = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
  70         if (err < 0) {
  71                 msi_bitmap_free(&msi_data->bitmap);
  72                 return err;
  73         }
  74
  75         return 0;
  76 }
  77
  78 static int ppc4xx_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
  79 {
  80         int int_no = -ENOMEM;
  81         unsigned int virq;
  82         struct msi_msg msg;
  83         struct msi_desc *entry;
  84         struct ppc4xx_msi *msi_data = &ppc4xx_msi;
  85
  86         list_for_each_entry(entry, &dev->msi_list, list) {
  87                 int_no = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
  88                 if (int_no >= 0)
  89                         break;
  90                 if (int_no < 0) {
  91                         pr_debug("%s: fail allocating msi interrupt\n",
  92                                         __func__);
  93                 }
  94                 virq = irq_of_parse_and_map(msi_data->msi_dev, int_no);
  95                 if (virq == NO_IRQ) {
  96                         dev_err(&dev->dev, "%s: fail mapping irq\n", __func__);
  97                         msi_bitmap_free_hwirqs(&msi_data->bitmap, int_no, 1);
  98                         return -ENOSPC;
  99                 }
 100                 dev_dbg(&dev->dev, "%s: virq = %d\n", __func__, virq);
 101
 102                 /* Setup msi address space */
 103                 msg.address_hi = msi_data->msi_addr_hi;
 104                 msg.address_lo = msi_data->msi_addr_lo;
 105
 106                 irq_set_msi_desc(virq, entry);
 107                 msg.data = int_no;
 108                 write_msi_msg(virq, &msg);
 109         }
 110         return 0;
 111 }
 112
 113 void ppc4xx_teardown_msi_irqs(struct pci_dev *dev)
 114 {
 115         struct msi_desc *entry;
 116         struct ppc4xx_msi *msi_data = &ppc4xx_msi;
 117
 118         dev_dbg(&dev->dev, "PCIE-MSI: tearing down msi irqs\n");
 119
 120         list_for_each_entry(entry, &dev->msi_list, list) {
 121                 if (entry->irq == NO_IRQ)
 122                         continue;
 123                 irq_set_msi_desc(entry->irq, NULL);
 124                 msi_bitmap_free_hwirqs(&msi_data->bitmap,
 125                                 virq_to_hw(entry->irq), 1);
 126                 irq_dispose_mapping(entry->irq);
 127         }
 128 }
 129
 130 static int ppc4xx_msi_check_device(struct pci_dev *pdev, int nvec, int type)
 131 {
 132         dev_dbg(&pdev->dev, "PCIE-MSI:%s called. vec %x type %d\n",
 133                 __func__, nvec, type);
 134         if (type == PCI_CAP_ID_MSIX)
 135                 pr_debug("ppc4xx msi: MSI-X untested, trying anyway.\n");
 136
 137         return 0;
 138 }
 139
 140 static int ppc4xx_setup_pcieh_hw(struct platform_device *dev,
 141                                  struct resource res, struct ppc4xx_msi *msi)
 142 {
 143         const u32 *msi_data;
 144         const u32 *msi_mask;
 145         const u32 *sdr_addr;
 146         dma_addr_t msi_phys;
 147         void *msi_virt;
 148
 149         sdr_addr = of_get_property(dev->dev.of_node, "sdr-base", NULL);
 150         if (!sdr_addr)
 151                 return -1;
 152
 153         SDR0_WRITE(sdr_addr, (u64)res.start >> 32);      /*HIGH addr */
 154         SDR0_WRITE(sdr_addr + 1, res.start & 0xFFFFFFFF); /* Low addr */
 155
 156
 157         msi->msi_dev = of_find_node_by_name(NULL, "ppc4xx-msi");
 158         if (msi->msi_dev)
 159                 return -ENODEV;
 160
 161         msi->msi_regs = of_iomap(msi->msi_dev, 0);
 162         if (!msi->msi_regs) {
 163                 dev_err(&dev->dev, "of_iomap problem failed\n");
 164                 return -ENOMEM;
 165         }
 166         dev_dbg(&dev->dev, "PCIE-MSI: msi register mapped 0x%x 0x%x\n",
 167                 (u32) (msi->msi_regs + PEIH_TERMADH), (u32) (msi->msi_regs));
 168
 169         msi_virt = dma_alloc_coherent(&dev->dev, 64, &msi_phys, GFP_KERNEL);
 170         msi->msi_addr_hi = 0x0;
 171         msi->msi_addr_lo = (u32) msi_phys;
 172         dev_dbg(&dev->dev, "PCIE-MSI: msi address 0x%x\n", msi->msi_addr_lo);
 173
 174         /* Progam the Interrupt handler Termination addr registers */
 175         out_be32(msi->msi_regs + PEIH_TERMADH, msi->msi_addr_hi);
 176         out_be32(msi->msi_regs + PEIH_TERMADL, msi->msi_addr_lo);
 177
 178         msi_data = of_get_property(dev->dev.of_node, "msi-data", NULL);
 179         if (!msi_data)
 180                 return -1;
 181         msi_mask = of_get_property(dev->dev.of_node, "msi-mask", NULL);
 182         if (!msi_mask)
 183                 return -1;
 184         /* Program MSI Expected data and Mask bits */
 185         out_be32(msi->msi_regs + PEIH_MSIED, *msi_data);
 186         out_be32(msi->msi_regs + PEIH_MSIMK, *msi_mask);
 187
 188         return 0;
 189 }
 190
 191 static int ppc4xx_of_msi_remove(struct platform_device *dev)
 192 {
 193         struct ppc4xx_msi *msi = dev->dev.platform_data;
 194         int i;
 195         int virq;
 196
 197         for (i = 0; i < NR_MSI_IRQS; i++) {
 198                 virq = msi->msi_virqs[i];
 199                 if (virq != NO_IRQ)
 200                         irq_dispose_mapping(virq);
 201         }
 202
 203         if (msi->bitmap.bitmap)
 204                 msi_bitmap_free(&msi->bitmap);
 205         iounmap(msi->msi_regs);
 206         of_node_put(msi->msi_dev);
 207         kfree(msi);
 208
 209         return 0;
 210 }
 211
 212 static int __devinit ppc4xx_msi_probe(struct platform_device *dev)
 213 {
 214         struct ppc4xx_msi *msi;
 215         struct resource res;
 216         int err = 0;
 217
 218         msi = &ppc4xx_msi;/*keep the msi data for further use*/
 219
 220         dev_dbg(&dev->dev, "PCIE-MSI: Setting up MSI support...\n");
 221
 222         msi = kzalloc(sizeof(struct ppc4xx_msi), GFP_KERNEL);
 223         if (!msi) {
 224                 dev_err(&dev->dev, "No memory for MSI structure\n");
 225                 return -ENOMEM;
 226         }
 227         dev->dev.platform_data = msi;
 228
 229         /* Get MSI ranges */
 230         err = of_address_to_resource(dev->dev.of_node, 0, &res);
 231         if (err) {
 232                 dev_err(&dev->dev, "%s resource error!\n",
 233                         dev->dev.of_node->full_name);
 234                 goto error_out;
 235         }
 236
 237         if (ppc4xx_setup_pcieh_hw(dev, res, msi))
 238                 goto error_out;
 239
 240         err = ppc4xx_msi_init_allocator(dev, msi);
 241         if (err) {
 242                 dev_err(&dev->dev, "Error allocating MSI bitmap\n");
 243                 goto error_out;
 244         }
 245
 246         ppc_md.setup_msi_irqs = ppc4xx_setup_msi_irqs;
 247         ppc_md.teardown_msi_irqs = ppc4xx_teardown_msi_irqs;
 248         ppc_md.msi_check_device = ppc4xx_msi_check_device;
 249         return err;
 250
 251 error_out:
 252         ppc4xx_of_msi_remove(dev);
 253         return err;
 254 }
 255 static const struct of_device_id ppc4xx_msi_ids[] = {
 256         {
 257                 .compatible = "amcc,ppc4xx-msi",
 258         },
 259         {}
 260 };
 261 static struct platform_driver ppc4xx_msi_driver = {
 262         .probe = ppc4xx_msi_probe,
 263         .remove = ppc4xx_of_msi_remove,
 264         .driver = {
 265                    .name = "ppc4xx-msi",
 266                    .owner = THIS_MODULE,
 267                    .of_match_table = ppc4xx_msi_ids,
 268                    },
 269
 270 };
 271
 272 static __init int ppc4xx_msi_init(void)
 273 {
 274         return platform_driver_register(&ppc4xx_msi_driver);
 275 }
 276
 277 subsys_initcall(ppc4xx_msi_init);