1Kernel driver max197 2==================== 3 4Author: 5 6 * Vivien Didelot <vivien.didelot@savoirfairelinux.com> 7 8Supported chips: 9 10 * Maxim MAX197 11 12 Prefix: 'max197' 13 14 Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX197.pdf 15 16 * Maxim MAX199 17 18 Prefix: 'max199' 19 20 Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX199.pdf 21 22Description 23----------- 24 25The A/D converters MAX197, and MAX199 are both 8-Channel, Multi-Range, 5V, 2612-Bit DAS with 8+4 Bus Interface and Fault Protection. 27 28The available ranges for the MAX197 are {0,-5V} to 5V, and {0,-10V} to 10V, 29while they are {0,-2V} to 2V, and {0,-4V} to 4V on the MAX199. 30 31Platform data 32------------- 33 34The MAX197 platform data (defined in linux/platform_data/max197.h) should be 35filled with a pointer to a conversion function, defined like:: 36 37 int convert(u8 ctrl); 38 39ctrl is the control byte to write to start a new conversion. 40On success, the function must return the 12-bit raw value read from the chip, 41or a negative error code otherwise. 42 43Control byte format: 44 45======= ========== ============================================ 46Bit Name Description 477,6 PD1,PD0 Clock and Power-Down modes 485 ACQMOD Internal or External Controlled Acquisition 494 RNG Full-scale voltage magnitude at the input 503 BIP Unipolar or Bipolar conversion mode 512,1,0 A2,A1,A0 Channel 52======= ========== ============================================ 53 54Sysfs interface 55--------------- 56 57 ============== ============================================================== 58 in[0-7]_input The conversion value for the corresponding channel. 59 RO 60 61 in[0-7]_min The lower limit (in mV) for the corresponding channel. 62 For the MAX197, it will be adjusted to -10000, -5000, or 0. 63 For the MAX199, it will be adjusted to -4000, -2000, or 0. 64 RW 65 66 in[0-7]_max The higher limit (in mV) for the corresponding channel. 67 For the MAX197, it will be adjusted to 0, 5000, or 10000. 68 For the MAX199, it will be adjusted to 0, 2000, or 4000. 69 RW 70 ============== ============================================================== 71