Add PCF8574 I/O Expander driver. Some cleanup also of other expander drivers.

drivers/ioexpander/Kconfig

@@ -44,6 +44,26 @@ config PCA9555_INT_NCALLBACKS
 	---help---
 		This is the maximum number of interrupt callbacks supported
 
+config PCA9555_SHADOW_MODE
+	bool "Use Shadow Mode instead of Read-Modify-Write Operations"
+	default n
+	---help---
+		This setting enables a mode where the output and pin
+		configuration registers are held in RAM.
+		With this for example we do not need to read back the
+		output-register every time we want to change one pin.
+		We do instead change the bit in the internal register
+		and then just write this register to the IO-Expander.
+		This reduces bus traffic and eliminates the problem of
+		EMC-caused toggling of output pins.
+
+config PCA9555_RETRY
+	bool "Retry to send commands and data at I2C communication errors"
+	default n
+	---help---
+		Retry to send commands and data if a I2C-communication
+		error occurs (eg. caused by EMC).
+
 endif # IOEXPANDER_PCA9555
 
 config IOEXPANDER_TCA64XX
@@ -52,7 +72,7 @@ config IOEXPANDER_TCA64XX
 	select I2C
 	depends on EXPERIMENTAL
 	---help---
-		Enable support for the NXP TCA64XX IO Expander
+		Enable support for the TCA64XX IO Expander
 
 if IOEXPANDER_TCA64XX
 
@@ -91,6 +111,51 @@ config TCA64XX_INT_POLLDELAY
 
 endif # IOEXPANDER_TCA64XX
 
+config IOEXPANDER_PCF8574
+	bool "PCF8574 I2C IO expander"
+	default n
+	select I2C
+	depends on EXPERIMENTAL
+	---help---
+		Enable support for the PCF8574 IO Expander
+
+if IOEXPANDER_PCF8574
+
+config PCF8574_MULTIPLE
+	bool "Multiple PCF8574 Devices"
+	default n
+	---help---
+		Can be defined to support multiple PCF8574 devices on board.
+
+config PCF8574_INT_ENABLE
+	bool "Enable PCF8574 Interrupt Support"
+	default n
+	select IOEXPANDER_INT_ENABLE
+	---help---
+		Enable driver interrupt functionality
+
+config PCF8574_INT_NCALLBACKS
+	int "Max number of interrupt callbacks"
+	default 4
+	depends on PCF8574_INT_ENABLE
+	---help---
+		This is the maximum number of interrupt callbacks supported
+
+config PCF8574_INT_POLL
+	bool "Enable interrupt poll"
+	default n
+	---help---
+		Enable polling for missed interrupts.
+
+config PCF8574_INT_POLLDELAY
+	int "Interrupt poll delay (used)"
+	default 500000
+	depends on PCF8574_INT_POLL
+	---help---
+		This microsecond delay defines the polling rate for missed interrupts.
+
+endif # IOEXPANDER_PCF8574
+
 config IOEXPANDER_INT_ENABLE
 	bool
 	default n
@@ -110,26 +175,6 @@ config IOEXPANDER_MULTIPIN
 		This settings enable the definition of routines for
 		optimized simultaneous access to multiple pins.
 
-config IOEXPANDER_SHADOW_MODE
-	bool "Use Shadow Mode instead of Read-Modify-Write Operations"
-	default n
-	---help---
-		This setting enables a mode where the output and pin
-		configuration registers are held in RAM.
-		With this for example we do not need to read back the
-		output-register every time we want to change one pin.
-		We do instead change the bit in the internal register
-		and then just write this register to the IO-Expander.
-		This reduces bus traffic and eliminates the problem of
-		EMC-caused toggling of output pins.
-
-config IOEXPANDER_RETRY
-	bool "Retry to send commands and data at I2C communication errors"
-	default n
-	---help---
-		Retry to send commands and data if a I2C-communication
-		error occurs (eg. caused by EMC).
-
 endif # IOEXPANDER
 
 config DEV_GPIO

drivers/ioexpander/Make.defs

@@ -48,6 +48,10 @@ ifeq ($(CONFIG_IOEXPANDER_TCA64XX),y)
   CSRCS += tca64xx.c
 endif
 
+ifeq ($(CONFIG_IOEXPANDER_PCF8574),y)
+  CSRCS += pcf8574.c
+endif
+
 endif # CONFIG_IOEXPANDER
 
 # GPIO test device driver (independent of IOEXPANDERS)

drivers/ioexpander/pca9555.c

@@ -235,7 +235,7 @@ static int pca9555_setbit(FAR struct pca9555_dev_s *pca, uint8_t addr,
 
   buf[0] = addr;
 
-#ifdef CONFIG_IOEXPANDER_SHADOW_MODE
+#ifdef CONFIG_PCA9555_SHADOW_MODE
   /* Get the shadowed register value */
 
   buf[1] = pca->sreg[addr];
@@ -259,14 +259,14 @@ static int pca9555_setbit(FAR struct pca9555_dev_s *pca, uint8_t addr,
       buf[1] &= ~(1 << pin);
     }
 
-#ifdef CONFIG_IOEXPANDER_SHADOW_MODE
+#ifdef CONFIG_PCA9555_SHADOW_MODE
   /* Save the new register value in the shadow register */
 
   pca->sreg[addr] = buf[1];
 #endif
 
   ret = pca9555_write(pca, buf, 2);
-#ifdef CONFIG_IOEXPANDER_RETRY
+#ifdef CONFIG_PCA9555_RETRY
   if (ret != OK)
     {
       /* Try again (only once) */
@@ -308,7 +308,7 @@ static int pca9555_getbit(FAR struct pca9555_dev_s *pca, uint8_t addr,
       return ret;
     }
 
-#ifdef CONFIG_IOEXPANDER_SHADOW_MODE
+#ifdef CONFIG_PCA9555_SHADOW_MODE
   /* Save the new register value in the shadow register */
 
   pca->sreg[addr] = buf;
@@ -508,7 +508,7 @@ static int pca9555_getmultibits(FAR struct pca9555_dev_s *pca, uint8_t addr,
       return ret;
     }
 
-#ifdef CONFIG_IOEXPANDER_SHADOW_MODE
+#ifdef CONFIG_PCA9555_SHADOW_MODE
   /* Save the new register value in the shadow register */
 
   pca->sreg[addr]   = buf[0];
@@ -575,7 +575,7 @@ static int pca9555_multiwritepin(FAR struct ioexpander_dev_s *dev,
    * this would not save much.
    */
 
-#ifndef CONFIG_IOEXPANDER_SHADOW_MODE
+#ifndef CONFIG_PCA9555_SHADOW_MODE
   ret = pca9555_writeread(pca, &addr, 1, &buf[1], 2);
   if (ret < 0)
     {
@@ -619,7 +619,7 @@ static int pca9555_multiwritepin(FAR struct ioexpander_dev_s *dev,
   /* Now write back the new pins states */
 
   buf[0] = addr;
-#ifdef CONFIG_IOEXPANDER_SHADOW_MODE
+#ifdef CONFIG_PCA9555_SHADOW_MODE
   /* Save the new register values in the shadow register */
   pca->sreg[addr] = buf[1];
   pca->sreg[addr+1] = buf[2];
@@ -809,7 +809,7 @@ static void pca9555_irqworker(void *arg)
   ret = pca9555_writeread(pca, &addr, 1, buf, 2);
   if (ret == OK)
     {
-#ifdef CONFIG_IOEXPANDER_SHADOW_MODE
+#ifdef CONFIG_PCA9555_SHADOW_MODE
       /* Don't forget to update the shadow registers at this point */
 
       pca->sreg[addr]   = buf[0];

drivers/ioexpander/pca9555.h

@@ -144,7 +144,7 @@ struct pca9555_dev_s
 {
   struct ioexpander_dev_s      dev;     /* Nested structure to allow casting as public gpio
                                          * expander. */
-#ifdef CONFIG_IOEXPANDER_SHADOW_MODE
+#ifdef CONFIG_PCA9555_SHADOW_MODE
   uint8_t sreg[8];                      /* Shadowed registers of the PCA9555 */
 #endif
 #ifdef CONFIG_PCA9555_MULTIPLE

drivers/ioexpander/tca64xx.c

@@ -427,7 +427,7 @@ static int tca64_direction(FAR struct ioexpander_dev_s *dev, uint8_t pin,
   DEBUGASSERT(priv != NULL && priv->config != NULL &&
               pin < CONFIG_IOEXPANDER_NPINS &&
               (direction == IOEXPANDER_DIRECTION_IN ||
-               direction == IOEXPANDER_DIRECTION_IN));
+               direction == IOEXPANDER_DIRECTION_OUT));
 
   gpioinfo("I2C addr=%02x pin=%u direction=%s\n",
            priv->config->address, pin,
@@ -702,7 +702,7 @@ errout_with_lock:
  *
  * Description:
  *   Read the actual PIN level. This can be different from the last value written
- *      to this pin. Required.
+ *   to this pin. Required.
  *
  * Input Parameters:
  *   dev    - Device-specific state data
@@ -1029,8 +1029,9 @@ static void tca64_int_update(void *handle, ioe_pinset_t input,
                              ioe_pinset_t mask)
 {
   struct tca64_dev_s *priv = handle;
-  uint32_t diff, ngios = tca64_ngpios(priv);
+  ioe_pinset_t diff;
   irqstate_t flags;
+  int ngios = tca64_ngpios(priv);
   int pin;
 
   flags = enter_critical_section();