lis2dh12: Better highpass filter config in activity int setup

Only set the LIS2DH12_HPIS2_MASK bit to LIS2DH12_CTRL_REG2 when
turning on highpass filtering in
lis2dh12_set_activity_interrupt_pin_2().

Remove unused function lis2dh12_set_highpass().

Author: tpikonen

drivers/lis2dh12/lis2dh12.c

@@ -295,13 +295,15 @@ lis2dh12_ret_t lis2dh12_set_activity_interrupt_pin_2(uint16_t mg)
     // //CTRLREG2 = 0x02
     // ctrl[0] = LIS2DH12_HPIS2_MASK;
     // lis2dh12_write_register(LIS2DH12_CTRL_REG2, ctrl, 1);
-
-    lis2dh12_set_highpass(LIS2DH12_HPIS2_MASK);
+    lis2dh12_read_register(LIS2DH12_CTRL_REG2, &cfg, 1);
+    cfg |= LIS2DH12_HPIS2_MASK;
+    lis2dh12_write_register(LIS2DH12_CTRL_REG2, &cfg, 1);
 
     // Enable interrupt 2 on X-Y-Z HI/LO.
     // INT2_CFG = 0x7F
     // ctrl[0] = 0x7F;
     // lis2dh12_write_register(LIS2DH12_INT2_CFG, ctrl, 1);
+    cfg = 0;
     cfg |= LIS2DH12_6D_MASK | LIS2DH12_ZHIE_MASK | LIS2DH12_ZLIE_MASK;
     cfg |= LIS2DH12_YHIE_MASK | LIS2DH12_YLIE_MASK;
     cfg |= LIS2DH12_XHIE_MASK | LIS2DH12_XLIE_MASK;
@@ -360,19 +362,6 @@ lis2dh12_ret_t lis2dh12_set_interrupt_configuration(uint8_t cfg, uint8_t functio
   return lis2dh12_write_register(target_reg, ctrl, 1);
 }
 
-/**
- * Setup high-pass functions of lis2dh12. Select mode, cutoff frequency, filter data, click, interrputs.
- *
- * @param highpass byte to write to filter, resets previous settings.
- * @return error code from SPI write. 
- */
-lis2dh12_ret_t lis2dh12_set_highpass(uint8_t highpass)
-{
-    uint8_t ctrl[1];
-    ctrl[0] = highpass;
-    return lis2dh12_write_register(LIS2DH12_CTRL_REG2, ctrl, 1);
-}
-
 /**
  *  Setup number of LSBs needed to trigger activity interrupt. 
  *

drivers/lis2dh12/lis2dh12.h

@@ -180,14 +180,6 @@ lis2dh12_ret_t lis2dh12_set_interrupts(uint8_t interrupts, uint8_t pin);
  */
 lis2dh12_ret_t lis2dh12_set_interrupt_configuration(uint8_t cfg, uint8_t function);
 
-/**
- * Setup high-pass functions of lis2dh12. Select mode, cutoff frequency, filter data, click, interrputs.
- *
- * @param highpass byte to write to filter, resets previous settings.
- * @return error code from SPI write. 
- */
-lis2dh12_ret_t lis2dh12_set_highpass(uint8_t highpass);
-
 /**
  *  Setup number of LSBs needed to trigger AOI interrupt function. 
  *  Note: this targets function 1 or 2, not pin.