2 * PowerNV LPC bus handling.
4 * Copyright 2013 IBM Corp.
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.
12 #include <linux/kernel.h>
14 #include <linux/bug.h>
15 #include <linux/debugfs.h>
17 #include <linux/slab.h>
19 #include <asm/machdep.h>
20 #include <asm/firmware.h>
24 #include <asm/uaccess.h>
25 #include <asm/debug.h>
27 static int opal_lpc_chip_id = -1;
29 static u8 opal_lpc_inb(unsigned long port)
34 if (opal_lpc_chip_id < 0 || port > 0xffff)
36 rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 1);
37 return rc ? 0xff : be32_to_cpu(data);
40 static __le16 __opal_lpc_inw(unsigned long port)
45 if (opal_lpc_chip_id < 0 || port > 0xfffe)
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);
52 static u16 opal_lpc_inw(unsigned long port)
54 return le16_to_cpu(__opal_lpc_inw(port));
57 static __le32 __opal_lpc_inl(unsigned long port)
62 if (opal_lpc_chip_id < 0 || port > 0xfffc)
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);
73 static u32 opal_lpc_inl(unsigned long port)
75 return le32_to_cpu(__opal_lpc_inl(port));
78 static void opal_lpc_outb(u8 val, unsigned long port)
80 if (opal_lpc_chip_id < 0 || port > 0xffff)
82 opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 1);
85 static void __opal_lpc_outw(__le16 val, unsigned long port)
87 if (opal_lpc_chip_id < 0 || port > 0xfffe)
90 opal_lpc_outb(val >> 8, port);
91 opal_lpc_outb(val , port + 1);
94 opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 2);
97 static void opal_lpc_outw(u16 val, unsigned long port)
99 __opal_lpc_outw(cpu_to_le16(val), port);
102 static void __opal_lpc_outl(__le32 val, unsigned long port)
104 if (opal_lpc_chip_id < 0 || port > 0xfffc)
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);
113 opal_lpc_write(opal_lpc_chip_id, OPAL_LPC_IO, port, val, 4);
116 static void opal_lpc_outl(u32 val, unsigned long port)
118 __opal_lpc_outl(cpu_to_le32(val), port);
121 static void opal_lpc_insb(unsigned long p, void *b, unsigned long c)
126 *(ptr++) = opal_lpc_inb(p);
129 static void opal_lpc_insw(unsigned long p, void *b, unsigned long c)
134 *(ptr++) = __opal_lpc_inw(p);
137 static void opal_lpc_insl(unsigned long p, void *b, unsigned long c)
142 *(ptr++) = __opal_lpc_inl(p);
145 static void opal_lpc_outsb(unsigned long p, const void *b, unsigned long c)
150 opal_lpc_outb(*(ptr++), p);
153 static void opal_lpc_outsw(unsigned long p, const void *b, unsigned long c)
155 const __le16 *ptr = b;
158 __opal_lpc_outw(*(ptr++), p);
161 static void opal_lpc_outsl(unsigned long p, const void *b, unsigned long c)
163 const __le32 *ptr = b;
166 __opal_lpc_outl(*(ptr++), p);
169 static const struct ppc_pci_io opal_lpc_io = {
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,
184 #ifdef CONFIG_DEBUG_FS
185 struct lpc_debugfs_entry {
186 enum OpalLPCAddressType lpc_type;
189 static ssize_t lpc_debug_read(struct file *filp, char __user *ubuf,
190 size_t count, loff_t *ppos)
192 struct lpc_debugfs_entry *lpc = filp->private_data;
193 u32 data, pos, len, todo;
197 if (!access_ok(VERIFY_WRITE, ubuf, count))
205 * Select access size based on count and alignment and
206 * access type. IO and MEM only support byte acceses,
210 if (lpc->lpc_type == OPAL_LPC_FW) {
211 if (todo > 3 && (pos & 3) == 0)
213 else if (todo > 1 && (pos & 1) == 0)
216 rc = opal_lpc_read(opal_lpc_chip_id, lpc->lpc_type, pos,
220 data = be32_to_cpu(bedata);
223 rc = __put_user((u32)data, (u32 __user *)ubuf);
226 rc = __put_user((u16)data, (u16 __user *)ubuf);
229 rc = __put_user((u8)data, (u8 __user *)ubuf);
242 static ssize_t lpc_debug_write(struct file *filp, const char __user *ubuf,
243 size_t count, loff_t *ppos)
245 struct lpc_debugfs_entry *lpc = filp->private_data;
246 u32 data, pos, len, todo;
249 if (!access_ok(VERIFY_READ, ubuf, count))
257 * Select access size based on count and alignment and
258 * access type. IO and MEM only support byte acceses,
262 if (lpc->lpc_type == OPAL_LPC_FW) {
263 if (todo > 3 && (pos & 3) == 0)
265 else if (todo > 1 && (pos & 1) == 0)
270 rc = __get_user(data, (u32 __user *)ubuf);
273 rc = __get_user(data, (u16 __user *)ubuf);
276 rc = __get_user(data, (u8 __user *)ubuf);
282 rc = opal_lpc_write(opal_lpc_chip_id, lpc->lpc_type, pos,
294 static const struct file_operations lpc_fops = {
295 .read = lpc_debug_read,
296 .write = lpc_debug_write,
298 .llseek = default_llseek,
301 static int opal_lpc_debugfs_create_type(struct dentry *folder,
303 enum OpalLPCAddressType type)
305 struct lpc_debugfs_entry *entry;
306 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
309 entry->lpc_type = type;
310 debugfs_create_file(fname, 0600, folder, entry, &lpc_fops);
314 static int opal_lpc_init_debugfs(void)
319 if (opal_lpc_chip_id < 0)
322 root = debugfs_create_dir("lpc", powerpc_debugfs_root);
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);
329 machine_device_initcall(powernv, opal_lpc_init_debugfs);
330 #endif /* CONFIG_DEBUG_FS */
332 void opal_lpc_init(void)
334 struct device_node *np;
337 * Look for a Power8 LPC bus tagged as "primary",
338 * we currently support only one though the OPAL APIs
339 * support any number.
341 for_each_compatible_node(np, NULL, "ibm,power8-lpc") {
342 if (!of_device_is_available(np))
344 if (!of_get_property(np, "primary", NULL))
346 opal_lpc_chip_id = of_get_ibm_chip_id(np);
349 if (opal_lpc_chip_id < 0)
352 /* Setup special IO ops */
353 ppc_pci_io = opal_lpc_io;
354 isa_io_special = true;
356 pr_info("OPAL: Power8 LPC bus found, chip ID %d\n", opal_lpc_chip_id);