Add backlight control

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3163 42af7a65-404d-4744-a932-0658087f49c3

2 files changed, 123 insertions, 3 deletions

diff --git a/nuttx/configs/olimex-lpc1766stk/src/lpc1766stk_internal.h b/nuttx/configs/olimex-lpc1766stk/src/lpc1766stk_internal.h
index d7244e17c..b1a461a24 100755
--- a/nuttx/configs/olimex-lpc1766stk/src/lpc1766stk_internal.h
+++ b/nuttx/configs/olimex-lpc1766stk/src/lpc1766stk_internal.h
@@ -165,12 +165,13 @@
  * P1[23]/MCFB1/PWM1[4]/MISO0        37  MISO0

  * P1[24]/MCFB2/PWM1[5]/MOSI0        38  MOSI0

  * P3[25]/MAT0[0]/PWM1[2]            27  LCD_RST

- * P3[26]/STCLK/MAT0[1]/PWM1[3]      26  LCD_BL

+ * P3[26]/STCLK/MAT0[1]/PWM1[3]      26  LCD_BL (PWM1)

  */

 

-#define LPC1766STK_LCD_CS  (GPIO_OUTPUT | GPIO_VALUE_ZERO | GPIO_PORT3 | GPIO_PIN25)

+#define LPC1766STK_LCD_CS  (GPIO_OUTPUT | GPIO_VALUE_ZERO | GPIO_PORT1 | GPIO_PIN21)

 #define LPC1766STK_LCD_RST (GPIO_OUTPUT | GPIO_VALUE_ZERO | GPIO_PORT3 | GPIO_PIN25)

-#define LPC1766STK_LCD_BL  (GPIO_OUTPUT | GPIO_VALUE_ZERO | GPIO_PORT3 | GPIO_PIN26)

+#define LPC1766STK_LCD_BL  GPIO_PWM1p3_3

+#define GPIO_PWM1p3        GPIO_PWM1p3_3

 

 /* SD/MMC GPIO                      PIN  SIGNAL NAME

  * -------------------------------- ---- --------------

diff --git a/nuttx/configs/olimex-lpc1766stk/src/up_lcd.c b/nuttx/configs/olimex-lpc1766stk/src/up_lcd.c
index 4f2a9123e..2fc3a4426 100755
--- a/nuttx/configs/olimex-lpc1766stk/src/up_lcd.c
+++ b/nuttx/configs/olimex-lpc1766stk/src/up_lcd.c
@@ -48,6 +48,7 @@
 #include <nuttx/lcd/lcd.h>
 #include <nuttx/lcd/nokia6100.h>
 
+#include "lpc17_syscon.h"
 #include "lpc17_internal.h"
 #include "lpc17stk_internal.h"
 
@@ -57,6 +58,16 @@
  * Pre-Processor Definitions
  ****************************************************************************/
 
+/* Check power setting */
+
+#if !defined(CONFIG_LCD_MAXPOWER) || CONFIG_LCD_MAXPOWER != 128
+#  error "CONFIG_LCD_MAXPOWER must be 128"
+#endif
+
+/* Backlight OFF PWM setting */
+
+#define NOKIA_BACKLIGHT_OFF 0x40
+
 /* Define the CONFIG_LCD_NOKIADBG to enable detailed debug output (stuff you
  * would never want to see unless you are debugging this file).
  *
@@ -85,6 +96,84 @@
  ****************************************************************************/
 
 /****************************************************************************
+ * Name: nokia_blinitialize
+ *
+ * Description:
+ *   Initialize PWM1 to manage the LCD backlight.
+ *
+ ****************************************************************************/
+
+void nokia_blinitialize(void)
+{
+  uint32_t regval;
+
+  /* Enable clocking of PWM1 */
+
+  regval = regreg32(LPC17_SYSCON_PCONP);
+  regval |= SYSCON_PCONP_PCPWM1;
+  putreg32(regval, LPC17_SYSCON_PCONP);
+
+  /* Disable and reset PWM1 */
+
+  regval  = getreg32(LPC17_PWM1_TCR);
+  regval &= ~(PWM_TCR_PWMEN|PWM_TCR_CNTREN);
+  regval |= PWM_TCR_CNTRRST;
+  putreg32(regval, LPC17_PWM1_TCR);
+
+  /* Put PWM1 in timer mode */
+
+  regval  = getreg32(LPC17_PWM1_CTCR);
+  regval &= ~PWM_CTCR_MODE_MASK;
+  regval |= PWM_CTCR_MODE_TIMER;
+  putreg32(regval, LPC17_PWM1_CTCR);
+
+  /* Reset on MR0 */
+
+  putreg32(PWM_MCR_MR0R, LPC17_PWM1_MCR);
+
+  /* Single edge controlled mod for PWM3 and enable output */
+
+  regval  = getreg32(LPC17_PWM1_PCR);
+  regval &= ~PWM_PCR_SEL3;
+  regval |= PWM_PCR_ENA3;
+  putreg32(regval, LPC17_PWM1_PCR);
+
+  /* Clear prescaler */
+
+  putreg32(0, LPC17_PWM1_PR);
+
+  /* Set 8-bit resolution */
+
+  putreg32(0xff, LPC17_PWM1_MCR);
+
+  /* Enable PWM match 1 latch */
+
+  regval  = getreg32(LPC17_PWM1_LER);
+  regval |= PWM_LER_M0EN;
+  putreg32(regval, LPC17_PWM1_LER);
+
+  /* Clear match register 3 */
+
+  putreg32(0, LPC17_PWM1_MR3);
+
+  /* Enable PWM1 */
+  
+  regval |= PWM_LER_M3EN;
+  putreg32(regval, LPC17_PWM1_LER);
+
+  regval  = getreg32(LPC17_PWM1_TCR);
+  regval &= ~(PWM_TCR_CNTRRST);
+  regval |= (PWM_TCR_PWMEN|PWM_TCR_CNTREN);
+  putreg32(regval, LPC17_PWM1_TCR);
+
+  nokia_backlight(0);
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
  * Name: up_nxdrvinit
  *
  * Description:
@@ -111,6 +200,10 @@ FAR struct lcd_dev_s *up_nxdrvinit(unsigned int devno)
   lpc17_gpiowrite(LPC1766STK_LCD_RST, true);
   up_msdelay(5);
 
+  /* Configure PWM1 to support the backlight */
+
+  nokia_blinitialize();
+
   /* Get the SSP port (configure as a Freescale SPI port) */
 
   spi = up_spiinitialize(0);
@@ -140,4 +233,30 @@ FAR struct lcd_dev_s *up_nxdrvinit(unsigned int devno)
   return NULL;
 }
 
+/****************************************************************************
+ * Name:  nokia_backlight
+ *
+ * Description:
+ *   The Nokia 6100 backlight is controlled by logic outside of the LCD
+ *   assembly.  This function must be provided by board specific logic to
+ *   manage the backlight.  This function will receive a power value (0:
+ *   full off - CONFIG_LCD_MAXPOWER: full on) and should set the backlight
+ *   accordingly.
+ *
+ *   On the Olimex LPC1766STK, the backlight level is controlled by PWM1.
+ *
+ ****************************************************************************/
+
+int nokia_backlight(unsigned int power)
+{
+  uint32_t regval;
+
+  putreg32(NOKIA_BACKLIGHT_OFF + power, LPC17_PWM1_MR3);
+  
+  regval  = getreg32(LPC17_PWM1_LER);
+  regval |= PWM_LER_M3EN;
+  putreg32(regval, LPC17_PWM1_LER);
+  return OK;
+}
+
 #endif /* CONFIG_NX_LCDDRIVER && CONFIG_LCD_NOKIA6100 && CONFIG_LPC17_SSP0 */