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
  16 #include <asm/machdep.h>
  17 #include <asm/firmware.h>
  18 #include <asm/xics.h>
  19 #include <asm/opal.h>
  20
  21 static int opal_lpc_chip_id = -1;
  22
  23 static u8 opal_lpc_inb(unsigned long port)
  24 {
  25         int64_t rc;
  26         uint32_t data;
  27
  28         if (opal_lpc_chip_id < 0 || port > 0xffff)
  29                 return 0xff;
  30         rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 1);
  31         return rc ? 0xff : data;
  32 }
  33
  34 static __le16 __opal_lpc_inw(unsigned long port)
  35 {
  36         int64_t rc;
  37         uint32_t data;
  38
  39         if (opal_lpc_chip_id < 0 || port > 0xfffe)
  40                 return 0xffff;
  41         if (port & 1)
  42                 return (__le16)opal_lpc_inb(port) << 8 | opal_lpc_inb(port + 1);
  43         rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 2);
  44         return rc ? 0xffff : data;
  45 }
  46 static u16 opal_lpc_inw(unsigned long port)
  47 {
  48         return le16_to_cpu(__opal_lpc_inw(port));
  49 }
  50
  51 static __le32 __opal_lpc_inl(unsigned long port)
  52 {
  53         int64_t rc;
  54         uint32_t data;
  55
  56         if (opal_lpc_chip_id < 0 || port > 0xfffc)
  57                 return 0xffffffff;
  58         if (port & 3)
  59                 return (__le32)opal_lpc_inb(port    ) << 24 |
  60                        (__le32)opal_lpc_inb(port + 1) << 16 |
  61                        (__le32)opal_lpc_inb(port + 2) <<  8 |
  62                                opal_lpc_inb(port + 3);
  63         rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 4);
  64         return rc ? 0xffffffff : data;
  65 }
  66
  67 static u32 opal_lpc_inl(unsigned long port)
  68 {
  69         return le32_to_cpu(__opal_lpc_inl(port));
  70 }
  71
  72 static void opal_lpc_outb(u8 val, unsigned long port)
  73 {
  74         if (opal_lpc_chip_id < 0 || port > 0xffff)
  75                 return;
  76         opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 1);
  77 }
  78
  79 static void __opal_lpc_outw(__le16 val, unsigned long port)
  80 {
  81         if (opal_lpc_chip_id < 0 || port > 0xfffe)
  82                 return;
  83         if (port & 1) {
  84                 opal_lpc_outb(val >> 8, port);
  85                 opal_lpc_outb(val     , port + 1);
  86                 return;
  87         }
  88         opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 2);
  89 }
  90
  91 static void opal_lpc_outw(u16 val, unsigned long port)
  92 {
  93         __opal_lpc_outw(cpu_to_le16(val), port);
  94 }
  95
  96 static void __opal_lpc_outl(__le32 val, unsigned long port)
  97 {
  98         if (opal_lpc_chip_id < 0 || port > 0xfffc)
  99                 return;
 100         if (port & 3) {
 101                 opal_lpc_outb(val >> 24, port);
 102                 opal_lpc_outb(val >> 16, port + 1);
 103                 opal_lpc_outb(val >>  8, port + 2);
 104                 opal_lpc_outb(val      , port + 3);
 105                 return;
 106         }
 107         opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 4);
 108 }
 109
 110 static void opal_lpc_outl(u32 val, unsigned long port)
 111 {
 112         __opal_lpc_outl(cpu_to_le32(val), port);
 113 }
 114
 115 static void opal_lpc_insb(unsigned long p, void *b, unsigned long c)
 116 {
 117         u8 *ptr = b;
 118
 119         while(c--)
 120                 *(ptr++) = opal_lpc_inb(p);
 121 }
 122
 123 static void opal_lpc_insw(unsigned long p, void *b, unsigned long c)
 124 {
 125         __le16 *ptr = b;
 126
 127         while(c--)
 128                 *(ptr++) = __opal_lpc_inw(p);
 129 }
 130
 131 static void opal_lpc_insl(unsigned long p, void *b, unsigned long c)
 132 {
 133         __le32 *ptr = b;
 134
 135         while(c--)
 136                 *(ptr++) = __opal_lpc_inl(p);
 137 }
 138
 139 static void opal_lpc_outsb(unsigned long p, const void *b, unsigned long c)
 140 {
 141         const u8 *ptr = b;
 142
 143         while(c--)
 144                 opal_lpc_outb(*(ptr++), p);
 145 }
 146
 147 static void opal_lpc_outsw(unsigned long p, const void *b, unsigned long c)
 148 {
 149         const __le16 *ptr = b;
 150
 151         while(c--)
 152                 __opal_lpc_outw(*(ptr++), p);
 153 }
 154
 155 static void opal_lpc_outsl(unsigned long p, const void *b, unsigned long c)
 156 {
 157         const __le32 *ptr = b;
 158
 159         while(c--)
 160                 __opal_lpc_outl(*(ptr++), p);
 161 }
 162
 163 static const struct ppc_pci_io opal_lpc_io = {
 164         .inb    = opal_lpc_inb,
 165         .inw    = opal_lpc_inw,
 166         .inl    = opal_lpc_inl,
 167         .outb   = opal_lpc_outb,
 168         .outw   = opal_lpc_outw,
 169         .outl   = opal_lpc_outl,
 170         .insb   = opal_lpc_insb,
 171         .insw   = opal_lpc_insw,
 172         .insl   = opal_lpc_insl,
 173         .outsb  = opal_lpc_outsb,
 174         .outsw  = opal_lpc_outsw,
 175         .outsl  = opal_lpc_outsl,
 176 };
 177
 178 void opal_lpc_init(void)
 179 {
 180         struct device_node *np;
 181
 182         /*
 183          * Look for a Power8 LPC bus tagged as "primary",
 184          * we currently support only one though the OPAL APIs
 185          * support any number.
 186          */
 187         for_each_compatible_node(np, NULL, "ibm,power8-lpc") {
 188                 if (!of_device_is_available(np))
 189                         continue;
 190                 if (!of_get_property(np, "primary", NULL))
 191                         continue;
 192                 opal_lpc_chip_id = of_get_ibm_chip_id(np);
 193                 break;
 194         }
 195         if (opal_lpc_chip_id < 0)
 196                 return;
 197
 198         /* Setup special IO ops */
 199         ppc_pci_io = opal_lpc_io;
 200         isa_io_special = true;
 201
 202         pr_info("OPAL: Power8 LPC bus found, chip ID %d\n", opal_lpc_chip_id);
 203 }