12874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later
23fafe9c2SBenjamin Herrenschmidt /*
33fafe9c2SBenjamin Herrenschmidt * PowerNV LPC bus handling.
43fafe9c2SBenjamin Herrenschmidt *
53fafe9c2SBenjamin Herrenschmidt * Copyright 2013 IBM Corp.
63fafe9c2SBenjamin Herrenschmidt */
73fafe9c2SBenjamin Herrenschmidt
83fafe9c2SBenjamin Herrenschmidt #include <linux/kernel.h>
93fafe9c2SBenjamin Herrenschmidt #include <linux/of.h>
103fafe9c2SBenjamin Herrenschmidt #include <linux/bug.h>
11fa2dbe2eSBenjamin Herrenschmidt #include <linux/io.h>
12fa2dbe2eSBenjamin Herrenschmidt #include <linux/slab.h>
13dbf77fedSAneesh Kumar K.V #include <linux/debugfs.h>
143fafe9c2SBenjamin Herrenschmidt
153fafe9c2SBenjamin Herrenschmidt #include <asm/machdep.h>
163fafe9c2SBenjamin Herrenschmidt #include <asm/firmware.h>
173fafe9c2SBenjamin Herrenschmidt #include <asm/opal.h>
1826a2056eSRob Herring #include <asm/prom.h>
197c0f6ba6SLinus Torvalds #include <linux/uaccess.h>
2038e9d36bSBenjamin Herrenschmidt #include <asm/isa-bridge.h>
213fafe9c2SBenjamin Herrenschmidt
223fafe9c2SBenjamin Herrenschmidt static int opal_lpc_chip_id = -1;
233fafe9c2SBenjamin Herrenschmidt
opal_lpc_inb(unsigned long port)243fafe9c2SBenjamin Herrenschmidt static u8 opal_lpc_inb(unsigned long port)
253fafe9c2SBenjamin Herrenschmidt {
263fafe9c2SBenjamin Herrenschmidt int64_t rc;
27803c2d2fSBenjamin Herrenschmidt __be32 data;
283fafe9c2SBenjamin Herrenschmidt
293fafe9c2SBenjamin Herrenschmidt if (opal_lpc_chip_id < 0 || port > 0xffff)
303fafe9c2SBenjamin Herrenschmidt return 0xff;
313fafe9c2SBenjamin Herrenschmidt rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 1);
32803c2d2fSBenjamin Herrenschmidt return rc ? 0xff : be32_to_cpu(data);
333fafe9c2SBenjamin Herrenschmidt }
343fafe9c2SBenjamin Herrenschmidt
__opal_lpc_inw(unsigned long port)353fafe9c2SBenjamin Herrenschmidt static __le16 __opal_lpc_inw(unsigned long port)
363fafe9c2SBenjamin Herrenschmidt {
373fafe9c2SBenjamin Herrenschmidt int64_t rc;
38803c2d2fSBenjamin Herrenschmidt __be32 data;
393fafe9c2SBenjamin Herrenschmidt
403fafe9c2SBenjamin Herrenschmidt if (opal_lpc_chip_id < 0 || port > 0xfffe)
413fafe9c2SBenjamin Herrenschmidt return 0xffff;
423fafe9c2SBenjamin Herrenschmidt if (port & 1)
433fafe9c2SBenjamin Herrenschmidt return (__le16)opal_lpc_inb(port) << 8 | opal_lpc_inb(port + 1);
443fafe9c2SBenjamin Herrenschmidt rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 2);
45803c2d2fSBenjamin Herrenschmidt return rc ? 0xffff : be32_to_cpu(data);
463fafe9c2SBenjamin Herrenschmidt }
opal_lpc_inw(unsigned long port)473fafe9c2SBenjamin Herrenschmidt static u16 opal_lpc_inw(unsigned long port)
483fafe9c2SBenjamin Herrenschmidt {
493fafe9c2SBenjamin Herrenschmidt return le16_to_cpu(__opal_lpc_inw(port));
503fafe9c2SBenjamin Herrenschmidt }
513fafe9c2SBenjamin Herrenschmidt
__opal_lpc_inl(unsigned long port)523fafe9c2SBenjamin Herrenschmidt static __le32 __opal_lpc_inl(unsigned long port)
533fafe9c2SBenjamin Herrenschmidt {
543fafe9c2SBenjamin Herrenschmidt int64_t rc;
55803c2d2fSBenjamin Herrenschmidt __be32 data;
563fafe9c2SBenjamin Herrenschmidt
573fafe9c2SBenjamin Herrenschmidt if (opal_lpc_chip_id < 0 || port > 0xfffc)
583fafe9c2SBenjamin Herrenschmidt return 0xffffffff;
593fafe9c2SBenjamin Herrenschmidt if (port & 3)
603fafe9c2SBenjamin Herrenschmidt return (__le32)opal_lpc_inb(port ) << 24 |
613fafe9c2SBenjamin Herrenschmidt (__le32)opal_lpc_inb(port + 1) << 16 |
623fafe9c2SBenjamin Herrenschmidt (__le32)opal_lpc_inb(port + 2) << 8 |
633fafe9c2SBenjamin Herrenschmidt opal_lpc_inb(port + 3);
643fafe9c2SBenjamin Herrenschmidt rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 4);
65803c2d2fSBenjamin Herrenschmidt return rc ? 0xffffffff : be32_to_cpu(data);
663fafe9c2SBenjamin Herrenschmidt }
673fafe9c2SBenjamin Herrenschmidt
opal_lpc_inl(unsigned long port)683fafe9c2SBenjamin Herrenschmidt static u32 opal_lpc_inl(unsigned long port)
693fafe9c2SBenjamin Herrenschmidt {
703fafe9c2SBenjamin Herrenschmidt return le32_to_cpu(__opal_lpc_inl(port));
713fafe9c2SBenjamin Herrenschmidt }
723fafe9c2SBenjamin Herrenschmidt
opal_lpc_outb(u8 val,unsigned long port)733fafe9c2SBenjamin Herrenschmidt static void opal_lpc_outb(u8 val, unsigned long port)
743fafe9c2SBenjamin Herrenschmidt {
753fafe9c2SBenjamin Herrenschmidt if (opal_lpc_chip_id < 0 || port > 0xffff)
763fafe9c2SBenjamin Herrenschmidt return;
773fafe9c2SBenjamin Herrenschmidt opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 1);
783fafe9c2SBenjamin Herrenschmidt }
793fafe9c2SBenjamin Herrenschmidt
__opal_lpc_outw(__le16 val,unsigned long port)803fafe9c2SBenjamin Herrenschmidt static void __opal_lpc_outw(__le16 val, unsigned long port)
813fafe9c2SBenjamin Herrenschmidt {
823fafe9c2SBenjamin Herrenschmidt if (opal_lpc_chip_id < 0 || port > 0xfffe)
833fafe9c2SBenjamin Herrenschmidt return;
843fafe9c2SBenjamin Herrenschmidt if (port & 1) {
853fafe9c2SBenjamin Herrenschmidt opal_lpc_outb(val >> 8, port);
863fafe9c2SBenjamin Herrenschmidt opal_lpc_outb(val , port + 1);
873fafe9c2SBenjamin Herrenschmidt return;
883fafe9c2SBenjamin Herrenschmidt }
893fafe9c2SBenjamin Herrenschmidt opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 2);
903fafe9c2SBenjamin Herrenschmidt }
913fafe9c2SBenjamin Herrenschmidt
opal_lpc_outw(u16 val,unsigned long port)923fafe9c2SBenjamin Herrenschmidt static void opal_lpc_outw(u16 val, unsigned long port)
933fafe9c2SBenjamin Herrenschmidt {
943fafe9c2SBenjamin Herrenschmidt __opal_lpc_outw(cpu_to_le16(val), port);
953fafe9c2SBenjamin Herrenschmidt }
963fafe9c2SBenjamin Herrenschmidt
__opal_lpc_outl(__le32 val,unsigned long port)973fafe9c2SBenjamin Herrenschmidt static void __opal_lpc_outl(__le32 val, unsigned long port)
983fafe9c2SBenjamin Herrenschmidt {
993fafe9c2SBenjamin Herrenschmidt if (opal_lpc_chip_id < 0 || port > 0xfffc)
1003fafe9c2SBenjamin Herrenschmidt return;
1013fafe9c2SBenjamin Herrenschmidt if (port & 3) {
1023fafe9c2SBenjamin Herrenschmidt opal_lpc_outb(val >> 24, port);
1033fafe9c2SBenjamin Herrenschmidt opal_lpc_outb(val >> 16, port + 1);
1043fafe9c2SBenjamin Herrenschmidt opal_lpc_outb(val >> 8, port + 2);
1053fafe9c2SBenjamin Herrenschmidt opal_lpc_outb(val , port + 3);
1063fafe9c2SBenjamin Herrenschmidt return;
1073fafe9c2SBenjamin Herrenschmidt }
1083fafe9c2SBenjamin Herrenschmidt opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 4);
1093fafe9c2SBenjamin Herrenschmidt }
1103fafe9c2SBenjamin Herrenschmidt
opal_lpc_outl(u32 val,unsigned long port)1113fafe9c2SBenjamin Herrenschmidt static void opal_lpc_outl(u32 val, unsigned long port)
1123fafe9c2SBenjamin Herrenschmidt {
1133fafe9c2SBenjamin Herrenschmidt __opal_lpc_outl(cpu_to_le32(val), port);
1143fafe9c2SBenjamin Herrenschmidt }
1153fafe9c2SBenjamin Herrenschmidt
opal_lpc_insb(unsigned long p,void * b,unsigned long c)1163fafe9c2SBenjamin Herrenschmidt static void opal_lpc_insb(unsigned long p, void *b, unsigned long c)
1173fafe9c2SBenjamin Herrenschmidt {
1183fafe9c2SBenjamin Herrenschmidt u8 *ptr = b;
1193fafe9c2SBenjamin Herrenschmidt
1203fafe9c2SBenjamin Herrenschmidt while(c--)
1213fafe9c2SBenjamin Herrenschmidt *(ptr++) = opal_lpc_inb(p);
1223fafe9c2SBenjamin Herrenschmidt }
1233fafe9c2SBenjamin Herrenschmidt
opal_lpc_insw(unsigned long p,void * b,unsigned long c)1243fafe9c2SBenjamin Herrenschmidt static void opal_lpc_insw(unsigned long p, void *b, unsigned long c)
1253fafe9c2SBenjamin Herrenschmidt {
1263fafe9c2SBenjamin Herrenschmidt __le16 *ptr = b;
1273fafe9c2SBenjamin Herrenschmidt
1283fafe9c2SBenjamin Herrenschmidt while(c--)
1293fafe9c2SBenjamin Herrenschmidt *(ptr++) = __opal_lpc_inw(p);
1303fafe9c2SBenjamin Herrenschmidt }
1313fafe9c2SBenjamin Herrenschmidt
opal_lpc_insl(unsigned long p,void * b,unsigned long c)1323fafe9c2SBenjamin Herrenschmidt static void opal_lpc_insl(unsigned long p, void *b, unsigned long c)
1333fafe9c2SBenjamin Herrenschmidt {
1343fafe9c2SBenjamin Herrenschmidt __le32 *ptr = b;
1353fafe9c2SBenjamin Herrenschmidt
1363fafe9c2SBenjamin Herrenschmidt while(c--)
1373fafe9c2SBenjamin Herrenschmidt *(ptr++) = __opal_lpc_inl(p);
1383fafe9c2SBenjamin Herrenschmidt }
1393fafe9c2SBenjamin Herrenschmidt
opal_lpc_outsb(unsigned long p,const void * b,unsigned long c)1403fafe9c2SBenjamin Herrenschmidt static void opal_lpc_outsb(unsigned long p, const void *b, unsigned long c)
1413fafe9c2SBenjamin Herrenschmidt {
1423fafe9c2SBenjamin Herrenschmidt const u8 *ptr = b;
1433fafe9c2SBenjamin Herrenschmidt
1443fafe9c2SBenjamin Herrenschmidt while(c--)
1453fafe9c2SBenjamin Herrenschmidt opal_lpc_outb(*(ptr++), p);
1463fafe9c2SBenjamin Herrenschmidt }
1473fafe9c2SBenjamin Herrenschmidt
opal_lpc_outsw(unsigned long p,const void * b,unsigned long c)1483fafe9c2SBenjamin Herrenschmidt static void opal_lpc_outsw(unsigned long p, const void *b, unsigned long c)
1493fafe9c2SBenjamin Herrenschmidt {
1503fafe9c2SBenjamin Herrenschmidt const __le16 *ptr = b;
1513fafe9c2SBenjamin Herrenschmidt
1523fafe9c2SBenjamin Herrenschmidt while(c--)
1533fafe9c2SBenjamin Herrenschmidt __opal_lpc_outw(*(ptr++), p);
1543fafe9c2SBenjamin Herrenschmidt }
1553fafe9c2SBenjamin Herrenschmidt
opal_lpc_outsl(unsigned long p,const void * b,unsigned long c)1563fafe9c2SBenjamin Herrenschmidt static void opal_lpc_outsl(unsigned long p, const void *b, unsigned long c)
1573fafe9c2SBenjamin Herrenschmidt {
1583fafe9c2SBenjamin Herrenschmidt const __le32 *ptr = b;
1593fafe9c2SBenjamin Herrenschmidt
1603fafe9c2SBenjamin Herrenschmidt while(c--)
1613fafe9c2SBenjamin Herrenschmidt __opal_lpc_outl(*(ptr++), p);
1623fafe9c2SBenjamin Herrenschmidt }
1633fafe9c2SBenjamin Herrenschmidt
1643fafe9c2SBenjamin Herrenschmidt static const struct ppc_pci_io opal_lpc_io = {
1653fafe9c2SBenjamin Herrenschmidt .inb = opal_lpc_inb,
1663fafe9c2SBenjamin Herrenschmidt .inw = opal_lpc_inw,
1673fafe9c2SBenjamin Herrenschmidt .inl = opal_lpc_inl,
1683fafe9c2SBenjamin Herrenschmidt .outb = opal_lpc_outb,
1693fafe9c2SBenjamin Herrenschmidt .outw = opal_lpc_outw,
1703fafe9c2SBenjamin Herrenschmidt .outl = opal_lpc_outl,
1713fafe9c2SBenjamin Herrenschmidt .insb = opal_lpc_insb,
1723fafe9c2SBenjamin Herrenschmidt .insw = opal_lpc_insw,
1733fafe9c2SBenjamin Herrenschmidt .insl = opal_lpc_insl,
1743fafe9c2SBenjamin Herrenschmidt .outsb = opal_lpc_outsb,
1753fafe9c2SBenjamin Herrenschmidt .outsw = opal_lpc_outsw,
1763fafe9c2SBenjamin Herrenschmidt .outsl = opal_lpc_outsl,
1773fafe9c2SBenjamin Herrenschmidt };
1783fafe9c2SBenjamin Herrenschmidt
179fa2dbe2eSBenjamin Herrenschmidt #ifdef CONFIG_DEBUG_FS
180fa2dbe2eSBenjamin Herrenschmidt struct lpc_debugfs_entry {
181fa2dbe2eSBenjamin Herrenschmidt enum OpalLPCAddressType lpc_type;
182fa2dbe2eSBenjamin Herrenschmidt };
183fa2dbe2eSBenjamin Herrenschmidt
lpc_debug_read(struct file * filp,char __user * ubuf,size_t count,loff_t * ppos)184fa2dbe2eSBenjamin Herrenschmidt static ssize_t lpc_debug_read(struct file *filp, char __user *ubuf,
185fa2dbe2eSBenjamin Herrenschmidt size_t count, loff_t *ppos)
186fa2dbe2eSBenjamin Herrenschmidt {
187fa2dbe2eSBenjamin Herrenschmidt struct lpc_debugfs_entry *lpc = filp->private_data;
188fa2dbe2eSBenjamin Herrenschmidt u32 data, pos, len, todo;
189fa2dbe2eSBenjamin Herrenschmidt int rc;
190fa2dbe2eSBenjamin Herrenschmidt
19196d4f267SLinus Torvalds if (!access_ok(ubuf, count))
192fa2dbe2eSBenjamin Herrenschmidt return -EFAULT;
193fa2dbe2eSBenjamin Herrenschmidt
194fa2dbe2eSBenjamin Herrenschmidt todo = count;
195fa2dbe2eSBenjamin Herrenschmidt while (todo) {
196fa2dbe2eSBenjamin Herrenschmidt pos = *ppos;
197fa2dbe2eSBenjamin Herrenschmidt
198fa2dbe2eSBenjamin Herrenschmidt /*
199fa2dbe2eSBenjamin Herrenschmidt * Select access size based on count and alignment and
2001fd02f66SJulia Lawall * access type. IO and MEM only support byte accesses,
201fa2dbe2eSBenjamin Herrenschmidt * FW supports all 3.
202fa2dbe2eSBenjamin Herrenschmidt */
203fa2dbe2eSBenjamin Herrenschmidt len = 1;
204fa2dbe2eSBenjamin Herrenschmidt if (lpc->lpc_type == OPAL_LPC_FW) {
205fa2dbe2eSBenjamin Herrenschmidt if (todo > 3 && (pos & 3) == 0)
206fa2dbe2eSBenjamin Herrenschmidt len = 4;
207fa2dbe2eSBenjamin Herrenschmidt else if (todo > 1 && (pos & 1) == 0)
208fa2dbe2eSBenjamin Herrenschmidt len = 2;
209fa2dbe2eSBenjamin Herrenschmidt }
210fa2dbe2eSBenjamin Herrenschmidt rc = opal_lpc_read(opal_lpc_chip_id, lpc->lpc_type, pos,
211bf19edd2SMichael Ellerman &data, len);
212fa2dbe2eSBenjamin Herrenschmidt if (rc)
213fa2dbe2eSBenjamin Herrenschmidt return -ENXIO;
214325e4114SBenjamin Herrenschmidt
215325e4114SBenjamin Herrenschmidt /*
216325e4114SBenjamin Herrenschmidt * Now there is some trickery with the data returned by OPAL
217325e4114SBenjamin Herrenschmidt * as it's the desired data right justified in a 32-bit BE
218325e4114SBenjamin Herrenschmidt * word.
219325e4114SBenjamin Herrenschmidt *
220325e4114SBenjamin Herrenschmidt * This is a very bad interface and I'm to blame for it :-(
221325e4114SBenjamin Herrenschmidt *
222325e4114SBenjamin Herrenschmidt * So we can't just apply a 32-bit swap to what comes from OPAL,
223325e4114SBenjamin Herrenschmidt * because user space expects the *bytes* to be in their proper
224325e4114SBenjamin Herrenschmidt * respective positions (ie, LPC position).
225325e4114SBenjamin Herrenschmidt *
226325e4114SBenjamin Herrenschmidt * So what we really want to do here is to shift data right
227325e4114SBenjamin Herrenschmidt * appropriately on a LE kernel.
228325e4114SBenjamin Herrenschmidt *
229325e4114SBenjamin Herrenschmidt * IE. If the LPC transaction has bytes B0, B1, B2 and B3 in that
230325e4114SBenjamin Herrenschmidt * order, we have in memory written to by OPAL at the "data"
231325e4114SBenjamin Herrenschmidt * pointer:
232325e4114SBenjamin Herrenschmidt *
233325e4114SBenjamin Herrenschmidt * Bytes: OPAL "data" LE "data"
234325e4114SBenjamin Herrenschmidt * 32-bit: B0 B1 B2 B3 B0B1B2B3 B3B2B1B0
235325e4114SBenjamin Herrenschmidt * 16-bit: B0 B1 0000B0B1 B1B00000
236325e4114SBenjamin Herrenschmidt * 8-bit: B0 000000B0 B0000000
237325e4114SBenjamin Herrenschmidt *
238325e4114SBenjamin Herrenschmidt * So a BE kernel will have the leftmost of the above in the MSB
239325e4114SBenjamin Herrenschmidt * and rightmost in the LSB and can just then "cast" the u32 "data"
240325e4114SBenjamin Herrenschmidt * down to the appropriate quantity and write it.
241325e4114SBenjamin Herrenschmidt *
242325e4114SBenjamin Herrenschmidt * However, an LE kernel can't. It doesn't need to swap because a
243325e4114SBenjamin Herrenschmidt * load from data followed by a store to user are going to preserve
244325e4114SBenjamin Herrenschmidt * the byte ordering which is the wire byte order which is what the
245325e4114SBenjamin Herrenschmidt * user wants, but in order to "crop" to the right size, we need to
246325e4114SBenjamin Herrenschmidt * shift right first.
247325e4114SBenjamin Herrenschmidt */
248fa2dbe2eSBenjamin Herrenschmidt switch(len) {
249fa2dbe2eSBenjamin Herrenschmidt case 4:
250fa2dbe2eSBenjamin Herrenschmidt rc = __put_user((u32)data, (u32 __user *)ubuf);
251fa2dbe2eSBenjamin Herrenschmidt break;
252fa2dbe2eSBenjamin Herrenschmidt case 2:
253325e4114SBenjamin Herrenschmidt #ifdef __LITTLE_ENDIAN__
254325e4114SBenjamin Herrenschmidt data >>= 16;
255325e4114SBenjamin Herrenschmidt #endif
256fa2dbe2eSBenjamin Herrenschmidt rc = __put_user((u16)data, (u16 __user *)ubuf);
257fa2dbe2eSBenjamin Herrenschmidt break;
258fa2dbe2eSBenjamin Herrenschmidt default:
259325e4114SBenjamin Herrenschmidt #ifdef __LITTLE_ENDIAN__
260325e4114SBenjamin Herrenschmidt data >>= 24;
261325e4114SBenjamin Herrenschmidt #endif
262fa2dbe2eSBenjamin Herrenschmidt rc = __put_user((u8)data, (u8 __user *)ubuf);
263fa2dbe2eSBenjamin Herrenschmidt break;
264fa2dbe2eSBenjamin Herrenschmidt }
265fa2dbe2eSBenjamin Herrenschmidt if (rc)
266fa2dbe2eSBenjamin Herrenschmidt return -EFAULT;
267fa2dbe2eSBenjamin Herrenschmidt *ppos += len;
268fa2dbe2eSBenjamin Herrenschmidt ubuf += len;
269fa2dbe2eSBenjamin Herrenschmidt todo -= len;
270fa2dbe2eSBenjamin Herrenschmidt }
271fa2dbe2eSBenjamin Herrenschmidt
272fa2dbe2eSBenjamin Herrenschmidt return count;
273fa2dbe2eSBenjamin Herrenschmidt }
274fa2dbe2eSBenjamin Herrenschmidt
lpc_debug_write(struct file * filp,const char __user * ubuf,size_t count,loff_t * ppos)275fa2dbe2eSBenjamin Herrenschmidt static ssize_t lpc_debug_write(struct file *filp, const char __user *ubuf,
276fa2dbe2eSBenjamin Herrenschmidt size_t count, loff_t *ppos)
277fa2dbe2eSBenjamin Herrenschmidt {
278fa2dbe2eSBenjamin Herrenschmidt struct lpc_debugfs_entry *lpc = filp->private_data;
279fa2dbe2eSBenjamin Herrenschmidt u32 data, pos, len, todo;
280fa2dbe2eSBenjamin Herrenschmidt int rc;
281fa2dbe2eSBenjamin Herrenschmidt
28296d4f267SLinus Torvalds if (!access_ok(ubuf, count))
283fa2dbe2eSBenjamin Herrenschmidt return -EFAULT;
284fa2dbe2eSBenjamin Herrenschmidt
285fa2dbe2eSBenjamin Herrenschmidt todo = count;
286fa2dbe2eSBenjamin Herrenschmidt while (todo) {
287fa2dbe2eSBenjamin Herrenschmidt pos = *ppos;
288fa2dbe2eSBenjamin Herrenschmidt
289fa2dbe2eSBenjamin Herrenschmidt /*
290fa2dbe2eSBenjamin Herrenschmidt * Select access size based on count and alignment and
291fa2dbe2eSBenjamin Herrenschmidt * access type. IO and MEM only support byte acceses,
292fa2dbe2eSBenjamin Herrenschmidt * FW supports all 3.
293fa2dbe2eSBenjamin Herrenschmidt */
294fa2dbe2eSBenjamin Herrenschmidt len = 1;
295fa2dbe2eSBenjamin Herrenschmidt if (lpc->lpc_type == OPAL_LPC_FW) {
296fa2dbe2eSBenjamin Herrenschmidt if (todo > 3 && (pos & 3) == 0)
297fa2dbe2eSBenjamin Herrenschmidt len = 4;
298fa2dbe2eSBenjamin Herrenschmidt else if (todo > 1 && (pos & 1) == 0)
299fa2dbe2eSBenjamin Herrenschmidt len = 2;
300fa2dbe2eSBenjamin Herrenschmidt }
301325e4114SBenjamin Herrenschmidt
302325e4114SBenjamin Herrenschmidt /*
303325e4114SBenjamin Herrenschmidt * Similarly to the read case, we have some trickery here but
304325e4114SBenjamin Herrenschmidt * it's different to handle. We need to pass the value to OPAL in
305325e4114SBenjamin Herrenschmidt * a register whose layout depends on the access size. We want
306325e4114SBenjamin Herrenschmidt * to reproduce the memory layout of the user, however we aren't
307325e4114SBenjamin Herrenschmidt * doing a load from user and a store to another memory location
308325e4114SBenjamin Herrenschmidt * which would achieve that. Here we pass the value to OPAL via
309325e4114SBenjamin Herrenschmidt * a register which is expected to contain the "BE" interpretation
310325e4114SBenjamin Herrenschmidt * of the byte sequence. IE: for a 32-bit access, byte 0 should be
311325e4114SBenjamin Herrenschmidt * in the MSB. So here we *do* need to byteswap on LE.
312325e4114SBenjamin Herrenschmidt *
313325e4114SBenjamin Herrenschmidt * User bytes: LE "data" OPAL "data"
314325e4114SBenjamin Herrenschmidt * 32-bit: B0 B1 B2 B3 B3B2B1B0 B0B1B2B3
315325e4114SBenjamin Herrenschmidt * 16-bit: B0 B1 0000B1B0 0000B0B1
316325e4114SBenjamin Herrenschmidt * 8-bit: B0 000000B0 000000B0
317325e4114SBenjamin Herrenschmidt */
318fa2dbe2eSBenjamin Herrenschmidt switch(len) {
319fa2dbe2eSBenjamin Herrenschmidt case 4:
320fa2dbe2eSBenjamin Herrenschmidt rc = __get_user(data, (u32 __user *)ubuf);
321325e4114SBenjamin Herrenschmidt data = cpu_to_be32(data);
322fa2dbe2eSBenjamin Herrenschmidt break;
323fa2dbe2eSBenjamin Herrenschmidt case 2:
324fa2dbe2eSBenjamin Herrenschmidt rc = __get_user(data, (u16 __user *)ubuf);
325325e4114SBenjamin Herrenschmidt data = cpu_to_be16(data);
326fa2dbe2eSBenjamin Herrenschmidt break;
327fa2dbe2eSBenjamin Herrenschmidt default:
328fa2dbe2eSBenjamin Herrenschmidt rc = __get_user(data, (u8 __user *)ubuf);
329fa2dbe2eSBenjamin Herrenschmidt break;
330fa2dbe2eSBenjamin Herrenschmidt }
331fa2dbe2eSBenjamin Herrenschmidt if (rc)
332fa2dbe2eSBenjamin Herrenschmidt return -EFAULT;
333fa2dbe2eSBenjamin Herrenschmidt
334fa2dbe2eSBenjamin Herrenschmidt rc = opal_lpc_write(opal_lpc_chip_id, lpc->lpc_type, pos,
335fa2dbe2eSBenjamin Herrenschmidt data, len);
336fa2dbe2eSBenjamin Herrenschmidt if (rc)
337fa2dbe2eSBenjamin Herrenschmidt return -ENXIO;
338fa2dbe2eSBenjamin Herrenschmidt *ppos += len;
339fa2dbe2eSBenjamin Herrenschmidt ubuf += len;
340fa2dbe2eSBenjamin Herrenschmidt todo -= len;
341fa2dbe2eSBenjamin Herrenschmidt }
342fa2dbe2eSBenjamin Herrenschmidt
343fa2dbe2eSBenjamin Herrenschmidt return count;
344fa2dbe2eSBenjamin Herrenschmidt }
345fa2dbe2eSBenjamin Herrenschmidt
346fa2dbe2eSBenjamin Herrenschmidt static const struct file_operations lpc_fops = {
347fa2dbe2eSBenjamin Herrenschmidt .read = lpc_debug_read,
348fa2dbe2eSBenjamin Herrenschmidt .write = lpc_debug_write,
349fa2dbe2eSBenjamin Herrenschmidt .open = simple_open,
350fa2dbe2eSBenjamin Herrenschmidt .llseek = default_llseek,
351fa2dbe2eSBenjamin Herrenschmidt };
352fa2dbe2eSBenjamin Herrenschmidt
opal_lpc_debugfs_create_type(struct dentry * folder,const char * fname,enum OpalLPCAddressType type)353fa2dbe2eSBenjamin Herrenschmidt static int opal_lpc_debugfs_create_type(struct dentry *folder,
354fa2dbe2eSBenjamin Herrenschmidt const char *fname,
355fa2dbe2eSBenjamin Herrenschmidt enum OpalLPCAddressType type)
356fa2dbe2eSBenjamin Herrenschmidt {
357fa2dbe2eSBenjamin Herrenschmidt struct lpc_debugfs_entry *entry;
358fa2dbe2eSBenjamin Herrenschmidt entry = kzalloc(sizeof(*entry), GFP_KERNEL);
359fa2dbe2eSBenjamin Herrenschmidt if (!entry)
360fa2dbe2eSBenjamin Herrenschmidt return -ENOMEM;
361fa2dbe2eSBenjamin Herrenschmidt entry->lpc_type = type;
362fa2dbe2eSBenjamin Herrenschmidt debugfs_create_file(fname, 0600, folder, entry, &lpc_fops);
363fa2dbe2eSBenjamin Herrenschmidt return 0;
364fa2dbe2eSBenjamin Herrenschmidt }
365fa2dbe2eSBenjamin Herrenschmidt
opal_lpc_init_debugfs(void)366fa2dbe2eSBenjamin Herrenschmidt static int opal_lpc_init_debugfs(void)
367fa2dbe2eSBenjamin Herrenschmidt {
368fa2dbe2eSBenjamin Herrenschmidt struct dentry *root;
369fa2dbe2eSBenjamin Herrenschmidt int rc = 0;
370fa2dbe2eSBenjamin Herrenschmidt
371fa2dbe2eSBenjamin Herrenschmidt if (opal_lpc_chip_id < 0)
372fa2dbe2eSBenjamin Herrenschmidt return -ENODEV;
373fa2dbe2eSBenjamin Herrenschmidt
374dbf77fedSAneesh Kumar K.V root = debugfs_create_dir("lpc", arch_debugfs_dir);
375fa2dbe2eSBenjamin Herrenschmidt
376fa2dbe2eSBenjamin Herrenschmidt rc |= opal_lpc_debugfs_create_type(root, "io", OPAL_LPC_IO);
377fa2dbe2eSBenjamin Herrenschmidt rc |= opal_lpc_debugfs_create_type(root, "mem", OPAL_LPC_MEM);
378fa2dbe2eSBenjamin Herrenschmidt rc |= opal_lpc_debugfs_create_type(root, "fw", OPAL_LPC_FW);
379fa2dbe2eSBenjamin Herrenschmidt return rc;
380fa2dbe2eSBenjamin Herrenschmidt }
381b14726c5SMichael Ellerman machine_device_initcall(powernv, opal_lpc_init_debugfs);
382fa2dbe2eSBenjamin Herrenschmidt #endif /* CONFIG_DEBUG_FS */
383fa2dbe2eSBenjamin Herrenschmidt
opal_lpc_init(void)3840b1c7643SMichael Ellerman void __init opal_lpc_init(void)
3853fafe9c2SBenjamin Herrenschmidt {
3863fafe9c2SBenjamin Herrenschmidt struct device_node *np;
3873fafe9c2SBenjamin Herrenschmidt
3883fafe9c2SBenjamin Herrenschmidt /*
3893fafe9c2SBenjamin Herrenschmidt * Look for a Power8 LPC bus tagged as "primary",
3903fafe9c2SBenjamin Herrenschmidt * we currently support only one though the OPAL APIs
3913fafe9c2SBenjamin Herrenschmidt * support any number.
3923fafe9c2SBenjamin Herrenschmidt */
3933fafe9c2SBenjamin Herrenschmidt for_each_compatible_node(np, NULL, "ibm,power8-lpc") {
3943fafe9c2SBenjamin Herrenschmidt if (!of_device_is_available(np))
3953fafe9c2SBenjamin Herrenschmidt continue;
3963fafe9c2SBenjamin Herrenschmidt if (!of_get_property(np, "primary", NULL))
3973fafe9c2SBenjamin Herrenschmidt continue;
3983fafe9c2SBenjamin Herrenschmidt opal_lpc_chip_id = of_get_ibm_chip_id(np);
3997d405a93SJulia Lawall of_node_put(np);
4003fafe9c2SBenjamin Herrenschmidt break;
4013fafe9c2SBenjamin Herrenschmidt }
4023fafe9c2SBenjamin Herrenschmidt if (opal_lpc_chip_id < 0)
4033fafe9c2SBenjamin Herrenschmidt return;
4043fafe9c2SBenjamin Herrenschmidt
405023b13a5SBenjamin Herrenschmidt /* Does it support direct mapping ? */
406*857d423cSRob Herring if (of_property_present(np, "ranges")) {
407023b13a5SBenjamin Herrenschmidt pr_info("OPAL: Found memory mapped LPC bus on chip %d\n",
408023b13a5SBenjamin Herrenschmidt opal_lpc_chip_id);
409023b13a5SBenjamin Herrenschmidt isa_bridge_init_non_pci(np);
410023b13a5SBenjamin Herrenschmidt } else {
411023b13a5SBenjamin Herrenschmidt pr_info("OPAL: Found non-mapped LPC bus on chip %d\n",
412023b13a5SBenjamin Herrenschmidt opal_lpc_chip_id);
413023b13a5SBenjamin Herrenschmidt
4143fafe9c2SBenjamin Herrenschmidt /* Setup special IO ops */
4153fafe9c2SBenjamin Herrenschmidt ppc_pci_io = opal_lpc_io;
4163fafe9c2SBenjamin Herrenschmidt isa_io_special = true;
417023b13a5SBenjamin Herrenschmidt }
4183fafe9c2SBenjamin Herrenschmidt }
419