1 Kernel driver max6650 1 Kernel driver max6650
2 ===================== 2 =====================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 * Maxim MAX6650 6 * Maxim MAX6650
7 7
8 Prefix: 'max6650' 8 Prefix: 'max6650'
9 9
10 Addresses scanned: none 10 Addresses scanned: none
11 11
12 Datasheet: http://pdfserv.maxim-ic.com/en/ 12 Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
13 13
14 * Maxim MAX6651 14 * Maxim MAX6651
15 15
16 Prefix: 'max6651' 16 Prefix: 'max6651'
17 17
18 Addresses scanned: none 18 Addresses scanned: none
19 19
20 Datasheet: http://pdfserv.maxim-ic.com/en/ 20 Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
21 21
22 Authors: 22 Authors:
23 - Hans J. Koch <hjk@hansjkoch.de> 23 - Hans J. Koch <hjk@hansjkoch.de>
24 - John Morris <john.morris@spirentcom.com> 24 - John Morris <john.morris@spirentcom.com>
25 - Claus Gindhart <claus.gindhart@kontron.co 25 - Claus Gindhart <claus.gindhart@kontron.com>
26 26
27 Description 27 Description
28 ----------- 28 -----------
29 29
30 This driver implements support for the Maxim M 30 This driver implements support for the Maxim MAX6650 and MAX6651.
31 31
32 The 2 devices are very similar, but the MAX655 32 The 2 devices are very similar, but the MAX6550 has a reduced feature
33 set, e.g. only one fan-input, instead of 4 for 33 set, e.g. only one fan-input, instead of 4 for the MAX6651.
34 34
35 The driver is not able to distinguish between 35 The driver is not able to distinguish between the 2 devices.
36 36
37 The driver provides the following sensor acces 37 The driver provides the following sensor accesses in sysfs:
38 38
39 =============== ======= ====================== 39 =============== ======= =======================================================
40 fan1_input ro fan tachometer speed i 40 fan1_input ro fan tachometer speed in RPM
41 fan2_input ro " 41 fan2_input ro "
42 fan3_input ro " 42 fan3_input ro "
43 fan4_input ro " 43 fan4_input ro "
44 fan1_target rw desired fan speed in R 44 fan1_target rw desired fan speed in RPM (closed loop mode only)
45 pwm1_enable rw regulator mode, 0=full 45 pwm1_enable rw regulator mode, 0=full on, 1=open loop, 2=closed loop
46 3=off 46 3=off
47 pwm1 rw relative speed (0-255) 47 pwm1 rw relative speed (0-255), 255=max. speed.
48 Used in open loop mode 48 Used in open loop mode only.
49 fan1_div rw sets the speed range t 49 fan1_div rw sets the speed range the inputs can handle. Legal
50 values are 1, 2, 4, an 50 values are 1, 2, 4, and 8. Use lower values for
51 faster fans. 51 faster fans.
52 =============== ======= ====================== 52 =============== ======= =======================================================
53 53
54 Usage notes 54 Usage notes
55 ----------- 55 -----------
56 56
57 This driver does not auto-detect devices. You 57 This driver does not auto-detect devices. You will have to instantiate the
58 devices explicitly. Please see Documentation/i 58 devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
59 details. 59 details.
60 60
61 Module parameters 61 Module parameters
62 ----------------- 62 -----------------
63 63
64 If your board has a BIOS that initializes the 64 If your board has a BIOS that initializes the MAX6650/6651 correctly, you can
65 simply load your module without parameters. It 65 simply load your module without parameters. It won't touch the configuration
66 registers then. If your board BIOS doesn't ini 66 registers then. If your board BIOS doesn't initialize the chip, or you want
67 different settings, you can set the following 67 different settings, you can set the following parameters:
68 68
69 voltage_12V: 5=5V fan, 12=12V fan, 0=don't cha 69 voltage_12V: 5=5V fan, 12=12V fan, 0=don't change
70 prescaler: Possible values are 1,2,4,8,16, or 70 prescaler: Possible values are 1,2,4,8,16, or 0 for don't change
71 clock: The clock frequency in Hz of the chip t 71 clock: The clock frequency in Hz of the chip the driver should assume [254000]
72 72
73 Please have a look at the MAX6650/6651 data sh 73 Please have a look at the MAX6650/6651 data sheet and make sure that you fully
74 understand the meaning of these parameters bef 74 understand the meaning of these parameters before you attempt to change them.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.