1 /***************************************************************************
2 * Copyright (C) 2010-2011 Hans de Goede <hdegoede@redhat.com> *
4 * This program is free software; you can redistribute it and/or modify *
5 * it under the terms of the GNU General Public License as published by *
6 * the Free Software Foundation; either version 2 of the License, or *
7 * (at your option) any later version. *
9 * This program is distributed in the hope that it will be useful, *
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
12 * GNU General Public License for more details. *
14 * You should have received a copy of the GNU General Public License *
15 * along with this program; if not, write to the *
16 * Free Software Foundation, Inc., *
17 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
18 ***************************************************************************/
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/platform_device.h>
25 #include <linux/err.h>
27 #include <linux/acpi.h>
28 #include <linux/delay.h>
29 #include "sch56xx-common.h"
31 #define SIO_SCH56XX_LD_EM 0x0C /* Embedded uController Logical Dev */
32 #define SIO_UNLOCK_KEY 0x55 /* Key to enable Super-I/O */
33 #define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */
35 #define SIO_REG_LDSEL 0x07 /* Logical device select */
36 #define SIO_REG_DEVID 0x20 /* Device ID */
37 #define SIO_REG_ENABLE 0x30 /* Logical device enable */
38 #define SIO_REG_ADDR 0x66 /* Logical device address (2 bytes) */
40 #define SIO_SCH5627_ID 0xC6 /* Chipset ID */
42 #define REGION_LENGTH 9
44 #define SCH56XX_CMD_READ 0x02
45 #define SCH56XX_CMD_WRITE 0x03
47 static struct platform_device
*sch56xx_pdev
;
49 /* Super I/O functions */
50 static inline int superio_inb(int base
, int reg
)
56 static inline int superio_enter(int base
)
58 /* Don't step on other drivers' I/O space by accident */
59 if (!request_muxed_region(base
, 2, "sch56xx")) {
60 pr_err("I/O address 0x%04x already in use\n", base
);
64 outb(SIO_UNLOCK_KEY
, base
);
69 static inline void superio_select(int base
, int ld
)
71 outb(SIO_REG_LDSEL
, base
);
75 static inline void superio_exit(int base
)
77 outb(SIO_LOCK_KEY
, base
);
78 release_region(base
, 2);
81 static int sch56xx_send_cmd(u16 addr
, u8 cmd
, u16 reg
, u8 v
)
86 * According to SMSC for the commands we use the maximum time for
87 * the EM to respond is 15 ms, but testing shows in practice it
88 * responds within 15-32 reads, so we first busy poll, and if
89 * that fails sleep a bit and try again until we are way past
90 * the 15 ms maximum response time.
92 const int max_busy_polls
= 64;
93 const int max_lazy_polls
= 32;
95 /* (Optional) Write-Clear the EC to Host Mailbox Register */
99 /* Set Mailbox Address Pointer to first location in Region 1 */
100 outb(0x00, addr
+ 2);
101 outb(0x80, addr
+ 3);
103 /* Write Request Packet Header */
104 outb(cmd
, addr
+ 4); /* VREG Access Type read:0x02 write:0x03 */
105 outb(0x01, addr
+ 5); /* # of Entries: 1 Byte (8-bit) */
106 outb(0x04, addr
+ 2); /* Mailbox AP to first data entry loc. */
108 /* Write Value field */
109 if (cmd
== SCH56XX_CMD_WRITE
)
112 /* Write Address field */
113 outb(reg
& 0xff, addr
+ 6);
114 outb(reg
>> 8, addr
+ 7);
116 /* Execute the Random Access Command */
117 outb(0x01, addr
); /* Write 01h to the Host-to-EC register */
119 /* EM Interface Polling "Algorithm" */
120 for (i
= 0; i
< max_busy_polls
+ max_lazy_polls
; i
++) {
121 if (i
>= max_busy_polls
)
123 /* Read Interrupt source Register */
125 /* Write Clear the interrupt source bits */
128 /* Command Completed ? */
132 if (i
== max_busy_polls
+ max_lazy_polls
) {
133 pr_err("Max retries exceeded reading virtual "
134 "register 0x%04hx (%d)\n", reg
, 1);
139 * According to SMSC we may need to retry this, but sofar I've always
140 * seen this succeed in 1 try.
142 for (i
= 0; i
< max_busy_polls
; i
++) {
143 /* Read EC-to-Host Register */
145 /* Command Completed ? */
150 pr_warn("EC reports: 0x%02x reading virtual register "
151 "0x%04hx\n", (unsigned int)val
, reg
);
153 if (i
== max_busy_polls
) {
154 pr_err("Max retries exceeded reading virtual "
155 "register 0x%04hx (%d)\n", reg
, 2);
160 * According to the SMSC app note we should now do:
162 * Set Mailbox Address Pointer to first location in Region 1 *
163 * outb(0x00, addr + 2);
164 * outb(0x80, addr + 3);
166 * But if we do that things don't work, so let's not.
169 /* Read Value field */
170 if (cmd
== SCH56XX_CMD_READ
)
171 return inb(addr
+ 4);
176 int sch56xx_read_virtual_reg(u16 addr
, u16 reg
)
178 return sch56xx_send_cmd(addr
, SCH56XX_CMD_READ
, reg
, 0);
180 EXPORT_SYMBOL(sch56xx_read_virtual_reg
);
182 int sch56xx_write_virtual_reg(u16 addr
, u16 reg
, u8 val
)
184 return sch56xx_send_cmd(addr
, SCH56XX_CMD_WRITE
, reg
, val
);
186 EXPORT_SYMBOL(sch56xx_write_virtual_reg
);
188 int sch56xx_read_virtual_reg16(u16 addr
, u16 reg
)
192 /* Read LSB first, this will cause the matching MSB to be latched */
193 lsb
= sch56xx_read_virtual_reg(addr
, reg
);
197 msb
= sch56xx_read_virtual_reg(addr
, reg
+ 1);
201 return lsb
| (msb
<< 8);
203 EXPORT_SYMBOL(sch56xx_read_virtual_reg16
);
205 int sch56xx_read_virtual_reg12(u16 addr
, u16 msb_reg
, u16 lsn_reg
,
210 /* Read MSB first, this will cause the matching LSN to be latched */
211 msb
= sch56xx_read_virtual_reg(addr
, msb_reg
);
215 lsn
= sch56xx_read_virtual_reg(addr
, lsn_reg
);
220 return (msb
<< 4) | (lsn
>> 4);
222 return (msb
<< 4) | (lsn
& 0x0f);
224 EXPORT_SYMBOL(sch56xx_read_virtual_reg12
);
226 static int __init
sch56xx_find(int sioaddr
, unsigned short *address
,
232 err
= superio_enter(sioaddr
);
236 devid
= superio_inb(sioaddr
, SIO_REG_DEVID
);
242 pr_debug("Unsupported device id: 0x%02x\n",
243 (unsigned int)devid
);
248 superio_select(sioaddr
, SIO_SCH56XX_LD_EM
);
250 if (!(superio_inb(sioaddr
, SIO_REG_ENABLE
) & 0x01)) {
251 pr_warn("Device not activated\n");
257 * Warning the order of the low / high byte is the other way around
258 * as on most other superio devices!!
260 *address
= superio_inb(sioaddr
, SIO_REG_ADDR
) |
261 superio_inb(sioaddr
, SIO_REG_ADDR
+ 1) << 8;
263 pr_warn("Base address not set\n");
269 superio_exit(sioaddr
);
273 static int __init
sch56xx_device_add(unsigned short address
, const char *name
)
275 struct resource res
= {
277 .end
= address
+ REGION_LENGTH
- 1,
278 .flags
= IORESOURCE_IO
,
282 sch56xx_pdev
= platform_device_alloc(name
, address
);
286 res
.name
= sch56xx_pdev
->name
;
287 err
= acpi_check_resource_conflict(&res
);
289 goto exit_device_put
;
291 err
= platform_device_add_resources(sch56xx_pdev
, &res
, 1);
293 pr_err("Device resource addition failed\n");
294 goto exit_device_put
;
297 err
= platform_device_add(sch56xx_pdev
);
299 pr_err("Device addition failed\n");
300 goto exit_device_put
;
306 platform_device_put(sch56xx_pdev
);
311 static int __init
sch56xx_init(void)
314 unsigned short address
;
317 err
= sch56xx_find(0x4e, &address
, &name
);
319 err
= sch56xx_find(0x2e, &address
, &name
);
323 return sch56xx_device_add(address
, name
);
326 static void __exit
sch56xx_exit(void)
328 platform_device_unregister(sch56xx_pdev
);
331 MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code");
332 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
333 MODULE_LICENSE("GPL");
335 module_init(sch56xx_init
);
336 module_exit(sch56xx_exit
);