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 #include <asm/prom.h> 21 22 static int opal_lpc_chip_id = -1; 23 24 static u8 opal_lpc_inb(unsigned long port) 25 { 26 int64_t rc; 27 uint32_t data; 28 29 if (opal_lpc_chip_id < 0 || port > 0xffff) 30 return 0xff; 31 rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 1); 32 return rc ? 0xff : data; 33 } 34 35 static __le16 __opal_lpc_inw(unsigned long port) 36 { 37 int64_t rc; 38 uint32_t data; 39 40 if (opal_lpc_chip_id < 0 || port > 0xfffe) 41 return 0xffff; 42 if (port & 1) 43 return (__le16)opal_lpc_inb(port) << 8 | opal_lpc_inb(port + 1); 44 rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 2); 45 return rc ? 0xffff : data; 46 } 47 static u16 opal_lpc_inw(unsigned long port) 48 { 49 return le16_to_cpu(__opal_lpc_inw(port)); 50 } 51 52 static __le32 __opal_lpc_inl(unsigned long port) 53 { 54 int64_t rc; 55 uint32_t data; 56 57 if (opal_lpc_chip_id < 0 || port > 0xfffc) 58 return 0xffffffff; 59 if (port & 3) 60 return (__le32)opal_lpc_inb(port ) << 24 | 61 (__le32)opal_lpc_inb(port + 1) << 16 | 62 (__le32)opal_lpc_inb(port + 2) << 8 | 63 opal_lpc_inb(port + 3); 64 rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 4); 65 return rc ? 0xffffffff : data; 66 } 67 68 static u32 opal_lpc_inl(unsigned long port) 69 { 70 return le32_to_cpu(__opal_lpc_inl(port)); 71 } 72 73 static void opal_lpc_outb(u8 val, unsigned long port) 74 { 75 if (opal_lpc_chip_id < 0 || port > 0xffff) 76 return; 77 opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 1); 78 } 79 80 static void __opal_lpc_outw(__le16 val, unsigned long port) 81 { 82 if (opal_lpc_chip_id < 0 || port > 0xfffe) 83 return; 84 if (port & 1) { 85 opal_lpc_outb(val >> 8, port); 86 opal_lpc_outb(val , port + 1); 87 return; 88 } 89 opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 2); 90 } 91 92 static void opal_lpc_outw(u16 val, unsigned long port) 93 { 94 __opal_lpc_outw(cpu_to_le16(val), port); 95 } 96 97 static void __opal_lpc_outl(__le32 val, unsigned long port) 98 { 99 if (opal_lpc_chip_id < 0 || port > 0xfffc) 100 return; 101 if (port & 3) { 102 opal_lpc_outb(val >> 24, port); 103 opal_lpc_outb(val >> 16, port + 1); 104 opal_lpc_outb(val >> 8, port + 2); 105 opal_lpc_outb(val , port + 3); 106 return; 107 } 108 opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 4); 109 } 110 111 static void opal_lpc_outl(u32 val, unsigned long port) 112 { 113 __opal_lpc_outl(cpu_to_le32(val), port); 114 } 115 116 static void opal_lpc_insb(unsigned long p, void *b, unsigned long c) 117 { 118 u8 *ptr = b; 119 120 while(c--) 121 *(ptr++) = opal_lpc_inb(p); 122 } 123 124 static void opal_lpc_insw(unsigned long p, void *b, unsigned long c) 125 { 126 __le16 *ptr = b; 127 128 while(c--) 129 *(ptr++) = __opal_lpc_inw(p); 130 } 131 132 static void opal_lpc_insl(unsigned long p, void *b, unsigned long c) 133 { 134 __le32 *ptr = b; 135 136 while(c--) 137 *(ptr++) = __opal_lpc_inl(p); 138 } 139 140 static void opal_lpc_outsb(unsigned long p, const void *b, unsigned long c) 141 { 142 const u8 *ptr = b; 143 144 while(c--) 145 opal_lpc_outb(*(ptr++), p); 146 } 147 148 static void opal_lpc_outsw(unsigned long p, const void *b, unsigned long c) 149 { 150 const __le16 *ptr = b; 151 152 while(c--) 153 __opal_lpc_outw(*(ptr++), p); 154 } 155 156 static void opal_lpc_outsl(unsigned long p, const void *b, unsigned long c) 157 { 158 const __le32 *ptr = b; 159 160 while(c--) 161 __opal_lpc_outl(*(ptr++), p); 162 } 163 164 static const struct ppc_pci_io opal_lpc_io = { 165 .inb = opal_lpc_inb, 166 .inw = opal_lpc_inw, 167 .inl = opal_lpc_inl, 168 .outb = opal_lpc_outb, 169 .outw = opal_lpc_outw, 170 .outl = opal_lpc_outl, 171 .insb = opal_lpc_insb, 172 .insw = opal_lpc_insw, 173 .insl = opal_lpc_insl, 174 .outsb = opal_lpc_outsb, 175 .outsw = opal_lpc_outsw, 176 .outsl = opal_lpc_outsl, 177 }; 178 179 void opal_lpc_init(void) 180 { 181 struct device_node *np; 182 183 /* 184 * Look for a Power8 LPC bus tagged as "primary", 185 * we currently support only one though the OPAL APIs 186 * support any number. 187 */ 188 for_each_compatible_node(np, NULL, "ibm,power8-lpc") { 189 if (!of_device_is_available(np)) 190 continue; 191 if (!of_get_property(np, "primary", NULL)) 192 continue; 193 opal_lpc_chip_id = of_get_ibm_chip_id(np); 194 break; 195 } 196 if (opal_lpc_chip_id < 0) 197 return; 198 199 /* Setup special IO ops */ 200 ppc_pci_io = opal_lpc_io; 201 isa_io_special = true; 202 203 pr_info("OPAL: Power8 LPC bus found, chip ID %d\n", opal_lpc_chip_id); 204 } 205