drivers/ioexpander/icjx: add option to set filters during initialization

This adds filters field to icjx_config_s structure that is passed
as an argument in icjx_initialize function. This field allows to
configure I/O filters (control world 1 and 3) with three possible
filters or disable them at all.

The filter configuration is currently only configurable during the
initialization, not at run time (the same as current source)

Signed-off-by: Michal Lenc <michallenc@seznam.cz>

drivers/ioexpander/icjx.c

@@ -1084,31 +1084,47 @@ FAR struct ioexpander_dev_s *icjx_initialize(FAR struct spi_dev_s *spi,
   ret = icjx_write(priv, ICJX_CTRL_WORD_2_A, regval, ICJX_NOB1);
   if (ret < 0)
     {
-      gpioerr("ERROR: Could write to ICJX_CTRL_WORD_2_A: %d!\n", ret);
+      gpioerr("ERROR: Couldn't write to ICJX_CTRL_WORD_2_A: %d!\n", ret);
       goto err;
     }
 
   ret = icjx_write(priv, ICJX_CTRL_WORD_2_B, regval, ICJX_NOB1);
   if (ret < 0)
     {
-      gpioerr("ERROR: Could write to ICJX_CTRL_WORD_2_B: %d!\n", ret);
+      gpioerr("ERROR: Couldn't write to ICJX_CTRL_WORD_2_B: %d!\n", ret);
       goto err;
     }
 
   /* Bypass filters as those are not yet supported. */
 
-  regval = ICJX_CTRL_WORD_1_BYP0 | ICJX_CTRL_WORD_1_BYP1;
+  if (config->filters != ICJX_CTRL_WORD_FILTER_DISABLED)
+    {
+      regval = ICJX_CTRL_WORD_3_ICLK;
+    }
+  else
+    {
+      regval = ICJX_CTRL_WORD_3_DIS;
+    }
+
+  ret = icjx_write(priv, ICJX_CTRL_WORD_3_B, regval, ICJX_NOB1);
+  if (ret < 0)
+    {
+      gpioerr("ERROR: Couldn't write to ICJX_CTRL_WORD_3_B: %d!\n", ret);
+      goto err;
+    }
+
+  regval = (config->filters << 4) | config->filters;
   ret = icjx_write(priv, ICJX_CTRL_WORD_1_A, regval, ICJX_NOB1);
   if (ret < 0)
     {
-      gpioerr("ERROR: Could write to ICJX_CTRL_WORD_1_A: %d!\n", ret);
+      gpioerr("ERROR: Couldn't write to ICJX_CTRL_WORD_1_A: %d!\n", ret);
       goto err;
     }
 
   ret = icjx_write(priv, ICJX_CTRL_WORD_1_B, regval, ICJX_NOB1);
   if (ret < 0)
     {
-      gpioerr("ERROR: Could write to ICJX_CTRL_WORD_1_B: %d!\n", ret);
+      gpioerr("ERROR: Couldn't write to ICJX_CTRL_WORD_1_B: %d!\n", ret);
       goto err;
     }
 

drivers/ioexpander/icjx.h

@@ -100,6 +100,11 @@
 #define ICJX_CTRL_WORD_2_NIOL   (1 << 3)
 #define ICJX_CTRL_WORD_2_NIOH   (1 << 7)
 
+/* Control Word 3 */
+
+#define ICJX_CTRL_WORD_3_ICLK   (1 << 2)
+#define ICJX_CTRL_WORD_3_DIS    (1 << 3)
+
 /* Control Word 4 */
 
 #define ICJX_CTRL_WORD_4_EOI    (1 << 7)

include/nuttx/ioexpander/icjx.h

@@ -42,6 +42,12 @@
 #define ICJX_CTRL_WORD_PULLUP_600U    6   /* 600 uA pull up */
 #define ICJX_CTRL_WORD_PULLUP_2M      7   /* 2 mA pull up*/
 
+#define ICJX_CTRL_WORD_FILTER_1 0         /* 14.5 * 1/CLK */
+#define ICJX_CTRL_WORD_FILTER_2 1         /* 896.5 * 1/CLK */
+#define ICJX_CTRL_WORD_FILTER_3 2         /* 3584.5 * 1/CLK */
+#define ICJX_CTRL_WORD_FILTER_4 3         /* 7168.5 * 1/CLK */
+#define ICJX_CTRL_WORD_FILTER_DISABLED 8  /* Filters are bypassed */
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/
@@ -66,6 +72,9 @@ struct icjx_config_s
   uint8_t current_src;  /* Current sources for pin nibbles (pull up,
                          * pull down) - see Control Word 2 register
                          */
+  uint8_t filters;      /* Filters configuration for pin nibbles - see
+                         * Control Word 1 register.
+                         */
   uint8_t addr;         /* Device address (set by A(1:0) pins) */
   uint8_t mode;         /* SPI mode */
   uint32_t frequency;   /* SPI frequency */