arch/powerpc/platforms/powernv/opal-lpc.c

   1 /*
   2  * PowerNV LPC bus handling.
   3  *
   4  * Copyright 2013 IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/of.h>
  14 #include <linux/bug.h>
  15 #include <linux/debugfs.h>
  16 #include <linux/io.h>
  17 #include <linux/slab.h>
  18
  19 #include <asm/machdep.h>
  20 #include <asm/firmware.h>
  21 #include <asm/xics.h>
  22 #include <asm/opal.h>
  23 #include <asm/prom.h>
  24 #include <asm/uaccess.h>
  25 #include <asm/debug.h>
  26
  27 static int opal_lpc_chip_id = -1;
  28
  29 static u8 opal_lpc_inb(unsigned long port)
  30 {
  31         int64_t rc;
  32         __be32 data;
  33
  34         if (opal_lpc_chip_id < 0 || port > 0xffff)
  35                 return 0xff;
  36         rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 1);
  37         return rc ? 0xff : be32_to_cpu(data);
  38 }
  39
  40 static __le16 __opal_lpc_inw(unsigned long port)
  41 {
  42         int64_t rc;
  43         __be32 data;
  44
  45         if (opal_lpc_chip_id < 0 || port > 0xfffe)
  46                 return 0xffff;
  47         if (port & 1)
  48                 return (__le16)opal_lpc_inb(port) << 8 | opal_lpc_inb(port + 1);
  49         rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 2);
  50         return rc ? 0xffff : be32_to_cpu(data);
  51 }
  52 static u16 opal_lpc_inw(unsigned long port)
  53 {
  54         return le16_to_cpu(__opal_lpc_inw(port));
  55 }
  56
  57 static __le32 __opal_lpc_inl(unsigned long port)
  58 {
  59         int64_t rc;
  60         __be32 data;
  61
  62         if (opal_lpc_chip_id < 0 || port > 0xfffc)
  63                 return 0xffffffff;
  64         if (port & 3)
  65                 return (__le32)opal_lpc_inb(port    ) << 24 |
  66                        (__le32)opal_lpc_inb(port + 1) << 16 |
  67                        (__le32)opal_lpc_inb(port + 2) <<  8 |
  68                                opal_lpc_inb(port + 3);
  69         rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 4);
  70         return rc ? 0xffffffff : be32_to_cpu(data);
  71 }
  72
  73 static u32 opal_lpc_inl(unsigned long port)
  74 {
  75         return le32_to_cpu(__opal_lpc_inl(port));
  76 }
  77
  78 static void opal_lpc_outb(u8 val, unsigned long port)
  79 {
  80         if (opal_lpc_chip_id < 0 || port > 0xffff)
  81                 return;
  82         opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 1);
  83 }
  84
  85 static void __opal_lpc_outw(__le16 val, unsigned long port)
  86 {
  87         if (opal_lpc_chip_id < 0 || port > 0xfffe)
  88                 return;
  89         if (port & 1) {
  90                 opal_lpc_outb(val >> 8, port);
  91                 opal_lpc_outb(val     , port + 1);
  92                 return;
  93         }
  94         opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 2);
  95 }
  96
  97 static void opal_lpc_outw(u16 val, unsigned long port)
  98 {
  99         __opal_lpc_outw(cpu_to_le16(val), port);
 100 }
 101
 102 static void __opal_lpc_outl(__le32 val, unsigned long port)
 103 {
 104         if (opal_lpc_chip_id < 0 || port > 0xfffc)
 105                 return;
 106         if (port & 3) {
 107                 opal_lpc_outb(val >> 24, port);
 108                 opal_lpc_outb(val >> 16, port + 1);
 109                 opal_lpc_outb(val >>  8, port + 2);
 110                 opal_lpc_outb(val      , port + 3);
 111                 return;
 112         }
 113         opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 4);
 114 }
 115
 116 static void opal_lpc_outl(u32 val, unsigned long port)
 117 {
 118         __opal_lpc_outl(cpu_to_le32(val), port);
 119 }
 120
 121 static void opal_lpc_insb(unsigned long p, void *b, unsigned long c)
 122 {
 123         u8 *ptr = b;
 124
 125         while(c--)
 126                 *(ptr++) = opal_lpc_inb(p);
 127 }
 128
 129 static void opal_lpc_insw(unsigned long p, void *b, unsigned long c)
 130 {
 131         __le16 *ptr = b;
 132
 133         while(c--)
 134                 *(ptr++) = __opal_lpc_inw(p);
 135 }
 136
 137 static void opal_lpc_insl(unsigned long p, void *b, unsigned long c)
 138 {
 139         __le32 *ptr = b;
 140
 141         while(c--)
 142                 *(ptr++) = __opal_lpc_inl(p);
 143 }
 144
 145 static void opal_lpc_outsb(unsigned long p, const void *b, unsigned long c)
 146 {
 147         const u8 *ptr = b;
 148
 149         while(c--)
 150                 opal_lpc_outb(*(ptr++), p);
 151 }
 152
 153 static void opal_lpc_outsw(unsigned long p, const void *b, unsigned long c)
 154 {
 155         const __le16 *ptr = b;
 156
 157         while(c--)
 158                 __opal_lpc_outw(*(ptr++), p);
 159 }
 160
 161 static void opal_lpc_outsl(unsigned long p, const void *b, unsigned long c)
 162 {
 163         const __le32 *ptr = b;
 164
 165         while(c--)
 166                 __opal_lpc_outl(*(ptr++), p);
 167 }
 168
 169 static const struct ppc_pci_io opal_lpc_io = {
 170         .inb    = opal_lpc_inb,
 171         .inw    = opal_lpc_inw,
 172         .inl    = opal_lpc_inl,
 173         .outb   = opal_lpc_outb,
 174         .outw   = opal_lpc_outw,
 175         .outl   = opal_lpc_outl,
 176         .insb   = opal_lpc_insb,
 177         .insw   = opal_lpc_insw,
 178         .insl   = opal_lpc_insl,
 179         .outsb  = opal_lpc_outsb,
 180         .outsw  = opal_lpc_outsw,
 181         .outsl  = opal_lpc_outsl,
 182 };
 183
 184 #ifdef CONFIG_DEBUG_FS
 185 struct lpc_debugfs_entry {
 186         enum OpalLPCAddressType lpc_type;
 187 };
 188
 189 static ssize_t lpc_debug_read(struct file *filp, char __user *ubuf,
 190                               size_t count, loff_t *ppos)
 191 {
 192         struct lpc_debugfs_entry *lpc = filp->private_data;
 193         u32 data, pos, len, todo;
 194         __be32 bedata;
 195         int rc;
 196
 197         if (!access_ok(VERIFY_WRITE, ubuf, count))
 198                 return -EFAULT;
 199
 200         todo = count;
 201         while (todo) {
 202                 pos = *ppos;
 203
 204                 /*
 205                  * Select access size based on count and alignment and
 206                  * access type. IO and MEM only support byte acceses,
 207                  * FW supports all 3.
 208                  */
 209                 len = 1;
 210                 if (lpc->lpc_type == OPAL_LPC_FW) {
 211                         if (todo > 3 && (pos & 3) == 0)
 212                                 len = 4;
 213                         else if (todo > 1 && (pos & 1) == 0)
 214                                 len = 2;
 215                 }
 216                 rc = opal_lpc_read(opal_lpc_chip_id, lpc->lpc_type, pos,
 217                                    &bedata, len);
 218                 if (rc)
 219                         return -ENXIO;
 220                 data = be32_to_cpu(bedata);
 221                 switch(len) {
 222                 case 4:
 223                         rc = __put_user((u32)data, (u32 __user *)ubuf);
 224                         break;
 225                 case 2:
 226                         rc = __put_user((u16)data, (u16 __user *)ubuf);
 227                         break;
 228                 default:
 229                         rc = __put_user((u8)data, (u8 __user *)ubuf);
 230                         break;
 231                 }
 232                 if (rc)
 233                         return -EFAULT;
 234                 *ppos += len;
 235                 ubuf += len;
 236                 todo -= len;
 237         }
 238
 239         return count;
 240 }
 241
 242 static ssize_t lpc_debug_write(struct file *filp, const char __user *ubuf,
 243                                size_t count, loff_t *ppos)
 244 {
 245         struct lpc_debugfs_entry *lpc = filp->private_data;
 246         u32 data, pos, len, todo;
 247         int rc;
 248
 249         if (!access_ok(VERIFY_READ, ubuf, count))
 250                 return -EFAULT;
 251
 252         todo = count;
 253         while (todo) {
 254                 pos = *ppos;
 255
 256                 /*
 257                  * Select access size based on count and alignment and
 258                  * access type. IO and MEM only support byte acceses,
 259                  * FW supports all 3.
 260                  */
 261                 len = 1;
 262                 if (lpc->lpc_type == OPAL_LPC_FW) {
 263                         if (todo > 3 && (pos & 3) == 0)
 264                                 len = 4;
 265                         else if (todo > 1 && (pos & 1) == 0)
 266                                 len = 2;
 267                 }
 268                 switch(len) {
 269                 case 4:
 270                         rc = __get_user(data, (u32 __user *)ubuf);
 271                         break;
 272                 case 2:
 273                         rc = __get_user(data, (u16 __user *)ubuf);
 274                         break;
 275                 default:
 276                         rc = __get_user(data, (u8 __user *)ubuf);
 277                         break;
 278                 }
 279                 if (rc)
 280                         return -EFAULT;
 281
 282                 rc = opal_lpc_write(opal_lpc_chip_id, lpc->lpc_type, pos,
 283                                     data, len);
 284                 if (rc)
 285                         return -ENXIO;
 286                 *ppos += len;
 287                 ubuf += len;
 288                 todo -= len;
 289         }
 290
 291         return count;
 292 }
 293
 294 static const struct file_operations lpc_fops = {
 295         .read =         lpc_debug_read,
 296         .write =        lpc_debug_write,
 297         .open =         simple_open,
 298         .llseek =       default_llseek,
 299 };
 300
 301 static int opal_lpc_debugfs_create_type(struct dentry *folder,
 302                                         const char *fname,
 303                                         enum OpalLPCAddressType type)
 304 {
 305         struct lpc_debugfs_entry *entry;
 306         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 307         if (!entry)
 308                 return -ENOMEM;
 309         entry->lpc_type = type;
 310         debugfs_create_file(fname, 0600, folder, entry, &lpc_fops);
 311         return 0;
 312 }
 313
 314 static int opal_lpc_init_debugfs(void)
 315 {
 316         struct dentry *root;
 317         int rc = 0;
 318
 319         if (opal_lpc_chip_id < 0)
 320                 return -ENODEV;
 321
 322         root = debugfs_create_dir("lpc", powerpc_debugfs_root);
 323
 324         rc |= opal_lpc_debugfs_create_type(root, "io", OPAL_LPC_IO);
 325         rc |= opal_lpc_debugfs_create_type(root, "mem", OPAL_LPC_MEM);
 326         rc |= opal_lpc_debugfs_create_type(root, "fw", OPAL_LPC_FW);
 327         return rc;
 328 }
 329 machine_device_initcall(powernv, opal_lpc_init_debugfs);
 330 #endif  /* CONFIG_DEBUG_FS */
 331
 332 void opal_lpc_init(void)
 333 {
 334         struct device_node *np;
 335
 336         /*
 337          * Look for a Power8 LPC bus tagged as "primary",
 338          * we currently support only one though the OPAL APIs
 339          * support any number.
 340          */
 341         for_each_compatible_node(np, NULL, "ibm,power8-lpc") {
 342                 if (!of_device_is_available(np))
 343                         continue;
 344                 if (!of_get_property(np, "primary", NULL))
 345                         continue;
 346                 opal_lpc_chip_id = of_get_ibm_chip_id(np);
 347                 break;
 348         }
 349         if (opal_lpc_chip_id < 0)
 350                 return;
 351
 352         /* Setup special IO ops */
 353         ppc_pci_io = opal_lpc_io;
 354         isa_io_special = true;
 355
 356         pr_info("OPAL: Power8 LPC bus found, chip ID %d\n", opal_lpc_chip_id);
 357 }