1*4882a593SmuzhiyunKernel driver max197 2*4882a593Smuzhiyun==================== 3*4882a593Smuzhiyun 4*4882a593SmuzhiyunAuthor: 5*4882a593Smuzhiyun 6*4882a593Smuzhiyun * Vivien Didelot <vivien.didelot@savoirfairelinux.com> 7*4882a593Smuzhiyun 8*4882a593SmuzhiyunSupported chips: 9*4882a593Smuzhiyun 10*4882a593Smuzhiyun * Maxim MAX197 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun Prefix: 'max197' 13*4882a593Smuzhiyun 14*4882a593Smuzhiyun Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX197.pdf 15*4882a593Smuzhiyun 16*4882a593Smuzhiyun * Maxim MAX199 17*4882a593Smuzhiyun 18*4882a593Smuzhiyun Prefix: 'max199' 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX199.pdf 21*4882a593Smuzhiyun 22*4882a593SmuzhiyunDescription 23*4882a593Smuzhiyun----------- 24*4882a593Smuzhiyun 25*4882a593SmuzhiyunThe A/D converters MAX197, and MAX199 are both 8-Channel, Multi-Range, 5V, 26*4882a593Smuzhiyun12-Bit DAS with 8+4 Bus Interface and Fault Protection. 27*4882a593Smuzhiyun 28*4882a593SmuzhiyunThe available ranges for the MAX197 are {0,-5V} to 5V, and {0,-10V} to 10V, 29*4882a593Smuzhiyunwhile they are {0,-2V} to 2V, and {0,-4V} to 4V on the MAX199. 30*4882a593Smuzhiyun 31*4882a593SmuzhiyunPlatform data 32*4882a593Smuzhiyun------------- 33*4882a593Smuzhiyun 34*4882a593SmuzhiyunThe MAX197 platform data (defined in linux/platform_data/max197.h) should be 35*4882a593Smuzhiyunfilled with a pointer to a conversion function, defined like:: 36*4882a593Smuzhiyun 37*4882a593Smuzhiyun int convert(u8 ctrl); 38*4882a593Smuzhiyun 39*4882a593Smuzhiyunctrl is the control byte to write to start a new conversion. 40*4882a593SmuzhiyunOn success, the function must return the 12-bit raw value read from the chip, 41*4882a593Smuzhiyunor a negative error code otherwise. 42*4882a593Smuzhiyun 43*4882a593SmuzhiyunControl byte format: 44*4882a593Smuzhiyun 45*4882a593Smuzhiyun======= ========== ============================================ 46*4882a593SmuzhiyunBit Name Description 47*4882a593Smuzhiyun7,6 PD1,PD0 Clock and Power-Down modes 48*4882a593Smuzhiyun5 ACQMOD Internal or External Controlled Acquisition 49*4882a593Smuzhiyun4 RNG Full-scale voltage magnitude at the input 50*4882a593Smuzhiyun3 BIP Unipolar or Bipolar conversion mode 51*4882a593Smuzhiyun2,1,0 A2,A1,A0 Channel 52*4882a593Smuzhiyun======= ========== ============================================ 53*4882a593Smuzhiyun 54*4882a593SmuzhiyunSysfs interface 55*4882a593Smuzhiyun--------------- 56*4882a593Smuzhiyun 57*4882a593Smuzhiyun ============== ============================================================== 58*4882a593Smuzhiyun in[0-7]_input The conversion value for the corresponding channel. 59*4882a593Smuzhiyun RO 60*4882a593Smuzhiyun 61*4882a593Smuzhiyun in[0-7]_min The lower limit (in mV) for the corresponding channel. 62*4882a593Smuzhiyun For the MAX197, it will be adjusted to -10000, -5000, or 0. 63*4882a593Smuzhiyun For the MAX199, it will be adjusted to -4000, -2000, or 0. 64*4882a593Smuzhiyun RW 65*4882a593Smuzhiyun 66*4882a593Smuzhiyun in[0-7]_max The higher limit (in mV) for the corresponding channel. 67*4882a593Smuzhiyun For the MAX197, it will be adjusted to 0, 5000, or 10000. 68*4882a593Smuzhiyun For the MAX199, it will be adjusted to 0, 2000, or 4000. 69*4882a593Smuzhiyun RW 70*4882a593Smuzhiyun ============== ============================================================== 71