apps/graphics/ft80x: Add interfaces to control the backlight. apps/examples/ft80x: Fade the display on and off between each example.

examples/ft80x/ft80x_main.c

@@ -166,6 +166,10 @@ static int ft80x_showname(int fd, FAR struct ft80x_dlbuffer_s *buffer,
   struct ft80x_cmd_text_s text;
   int ret;
 
+  /* Mkae sure that the backlight off */
+
+  (void)ft80x_backlight_set(fd, 0);
+
   /* Create the display list */
 
   ret = ft80x_dl_start(fd, buffer, false);
@@ -206,9 +210,10 @@ static int ft80x_showname(int fd, FAR struct ft80x_dlbuffer_s *buffer,
       return ret;
     }
 
-  /* Wait bit so that the user can read the name */
+  /* Fade on, then wait bit so that the user can read the name */
 
-  sleep(2);
+  (void)ft80x_backlight_fade(fd, 100, 1000);
+  (void)sleep(1);
   return OK;
 }
 
@@ -236,7 +241,7 @@ static int ft80x_example(int fd, FAR struct ft80x_dlbuffer_s *buffer,
       return ret;
     }
 
-  /* Then executte the example */
+  /* Then execute the example */
 
   ret = example->func(fd, buffer);
   if (ret < 0)
@@ -245,9 +250,10 @@ static int ft80x_example(int fd, FAR struct ft80x_dlbuffer_s *buffer,
       return ret;
     }
 
-  /* Wait a bit */
+  /* Wait a bit, then fade out */
 
-  sleep(4);
+  sleep(3);
+  (void)ft80x_backlight_fade(fd, 0, 1000);
   return OK;
 }
 

graphics/ft80x/Makefile

@@ -41,7 +41,7 @@ include $(APPDIR)/Make.defs
 
 ASRCS  =
 CSRCS  = ft80x_dl.c ft80x_ramg.c ft80x_ramdl.c ft80x_ramcmd.c ft80x_coproc.c
-CSRCS += ft80x_touch.c ft80x_regs.c
+CSRCS += ft80x_touch.c ft80x_backlight.c ft80x_regs.c
 
 AOBJS = $(ASRCS:.S=$(OBJEXT))
 COBJS = $(CSRCS:.c=$(OBJEXT))

graphics/ft80x/ft80x_backlight.c

@@ -0,0 +1,133 @@
+/****************************************************************************
+ * apps/graphics/ft80x/ft80x_backlight.c
+ *
+ *   Copyright (C) 2018 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/ioctl.h>
+#include <stdint.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <nuttx/lcd/ft80x.h>
+
+#include "graphics/ft80x.h"
+#include "ft80x.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ft80x_backlight_set
+ *
+ * Description:
+ *   Set the backlight intensity via the PWM duty.
+ *
+ * Input Parameters:
+ *   fd     - The file descriptor of the FT80x device.  Opened by the caller
+ *            with write access.
+ *   duty   - The new backlight duty (as a percentage 0..100)
+ *   delay  - The duration of the fade in milliseconds.
+ *
+ * Returned Value:
+ *   Zero (OK) on success.  A negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int ft80x_backlight_set(int fd, uint8_t duty)
+{
+  uint16_t duty128;
+  int ret;
+
+  DEBUGASSERT(duty <= 100);
+
+  /* 0% corresponds to the value 0, but 100% corresponds to the value 128 */
+
+  duty128 = ((uint16_t)duty << 7) / 100;
+
+  /* Perform the IOCTL to set the backlight duty */
+
+  ret = ft80x_putreg8(fd, FT80X_REG_PWM_DUTY, (uint8_t)duty128);
+  if (ret < 0)
+    {
+      ft80x_err("ERROR: ft80x_putreg8 failed: %d\n", ret);
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: ft80x_backlight_fade
+ *
+ * Description:
+ *   Change the backlight intensity with a controllable fade.
+ *
+ * Input Parameters:
+ *   fd     - The file descriptor of the FT80x device.  Opened by the caller
+ *            with write access.
+ *   duty   - The terminal duty (as a percentage 0..100)
+ *   delay  - The duration of the fade in milliseconds (10..16700)
+ *
+ * Returned Value:
+ *   Zero (OK) on success.  A negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int ft80x_backlight_fade(int fd, uint8_t duty, uint16_t delay)
+{
+  struct ft80x_fade_s fade;
+  int ret;
+
+  DEBUGASSERT(duty <= 100);
+
+  /* Perform the IOCTL to perform the fade */
+
+  fade.delay = duty;
+  fade.delay = delay;
+
+  ret = ioctl(fd, FT80X_IOC_FADE, (unsigned long)((uintptr_t)&fade));
+  if (ret < 0)
+    {
+      int errcode = errno;
+      ft80x_err("ERROR: ioctl(FT80X_IOC_FADE) failed: %d\n", errcode);
+      ret = -errcode;
+    }
+
+  return ret;
+}

include/graphics/ft80x.h

@@ -326,6 +326,44 @@ int ft80x_ramg_write(int fd, unsigned int offset, FAR const void *data,
 
 int ft80x_touch_gettransform(int fd, FAR uint32_t matrix[6]);
 
+/****************************************************************************
+ * Name: ft80x_backlight_set
+ *
+ * Description:
+ *   Set the backlight intensity via the PWM duty.
+ *
+ * Input Parameters:
+ *   fd     - The file descriptor of the FT80x device.  Opened by the caller
+ *            with write access.
+ *   duty   - The new backlight duty (as a percentage 0..100)
+ *   delay  - The duration of the fade in milliseconds.
+ *
+ * Returned Value:
+ *   Zero (OK) on success.  A negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int ft80x_backlight_set(int fd, uint8_t duty);
+
+/****************************************************************************
+ * Name: ft80x_backlight_fade
+ *
+ * Description:
+ *   Change the backlight intensity with a controllable fade.
+ *
+ * Input Parameters:
+ *   fd     - The file descriptor of the FT80x device.  Opened by the caller
+ *            with write access.
+ *   duty   - The terminal duty (as a percentage 0..100)
+ *   delay  - The duration of the fade in milliseconds (10..16700).
+ *
+ * Returned Value:
+ *   Zero (OK) on success.  A negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int ft80x_backlight_fade(int fd, uint8_t duty, uint16_t delay);
+
 #undef EXTERN
 #ifdef __cplusplus
 }