From 339f5f8e51e335b940e6728e51521fdf2b093316 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Sun, 8 Jun 2014 08:25:39 -0600
Subject: [PATCH] SAMA5: Add TWI3 support

---
 arch/arm/src/sama5/Kconfig   |  9 +++++--
 arch/arm/src/sama5/sam_twi.c | 50 ++++++++++++++++++++++++++++++++++--
 2 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/arch/arm/src/sama5/Kconfig b/arch/arm/src/sama5/Kconfig
index 960f1f80a2..4cf74c3dd5 100644
--- a/arch/arm/src/sama5/Kconfig
+++ b/arch/arm/src/sama5/Kconfig
@@ -1778,7 +1778,7 @@ config SAMA5_SPI_REGDEBUG
 endmenu # SPI device driver options
 endif # SAMA5_SPI0 || SAMA5_SPI1
 
-if SAMA5_TWI0 || SAMA5_TWI1 || SAMA5_TWI2
+if SAMA5_TWI0 || SAMA5_TWI1 || SAMA5_TWI2 || SAMA5_TWI3
 
 menu "TWI device driver options"
 
@@ -1797,6 +1797,11 @@ config SAMA5_TWI2_FREQUENCY
 	default 100000
 	depends on SAMA5_TWI2
 
+config SAMA5_TWI3_FREQUENCY
+	int "TWI3 Frequency"
+	default 100000
+	depends on SAMA5_TWI3
+
 config SAMA5_TWI_REGDEBUG
 	bool "TWI register level debug"
 	depends on DEBUG
@@ -1806,7 +1811,7 @@ config SAMA5_TWI_REGDEBUG
 		Very invasive! Requires also DEBUG.
 
 endmenu # TWI device driver options
-endif # SAMA5_TWI0 || SAMA5_TWI1 || SAMA5_TWI2
+endif # SAMA5_TWI0 || SAMA5_TWI1 || SAMA5_TWI2 || SAMA5_TWI3
 
 if SAMA5_SSC0 || SAMA5_SSC1
 menu "SSC Configuration"
diff --git a/arch/arm/src/sama5/sam_twi.c b/arch/arm/src/sama5/sam_twi.c
index 1cde9bdb63..a2899729a7 100644
--- a/arch/arm/src/sama5/sam_twi.c
+++ b/arch/arm/src/sama5/sam_twi.c
@@ -70,7 +70,8 @@
 #include "sam_pio.h"
 #include "sam_twi.h"
 
-#if defined(CONFIG_SAMA5_TWI0) || defined(CONFIG_SAMA5_TWI1) || defined(CONFIG_SAMA5_TWI2)
+#if defined(CONFIG_SAMA5_TWI0) || defined(CONFIG_SAMA5_TWI1) || \
+    defined(CONFIG_SAMA5_TWI2) || defined(CONFIG_SAMA5_TWI3)
 
 /*******************************************************************************
  * Pre-processor Definitions
@@ -89,6 +90,10 @@
  #define CONFIG_SAMA5_TWI2_FREQUENCY 100000
 #endif
 
+#ifndef CONFIG_SAMA5_TWI3_FREQUENCY
+ #define CONFIG_SAMA5_TWI3_FREQUENCY 100000
+#endif
+
 /* Driver internal definitions *************************************************/
 
 #define TWI_TIMEOUT ((20 * CLK_TCK) / 1000) /* 20 mS */
@@ -186,6 +191,9 @@ static int twi1_interrupt(int irq, FAR void *context);
 #ifdef CONFIG_SAMA5_TWI2
 static int twi2_interrupt(int irq, FAR void *context);
 #endif
+#ifdef CONFIG_SAMA5_TWI3
+static int twi3_interrupt(int irq, FAR void *context);
+#endif
 static void twi_timeout(int argc, uint32_t arg, ...);
 
 static void twi_startread(struct twi_dev_s *priv, struct i2c_msg_s *msg);
@@ -237,6 +245,10 @@ static struct twi_dev_s g_twi1;
 static struct twi_dev_s g_twi2;
 #endif
 
+#ifdef CONFIG_SAMA5_TWI3
+static struct twi_dev_s g_twi3;
+#endif
+
 struct i2c_ops_s g_twiops =
 {
   .setfrequency     = twi_setfrequency,
@@ -620,6 +632,13 @@ static int twi2_interrupt(int irq, FAR void *context)
 }
 #endif
 
+#ifdef CONFIG_SAMA5_TWI3
+static int twi3_interrupt(int irq, FAR void *context)
+{
+  return twi_interrupt(&g_twi3);
+}
+#endif
+
 /*******************************************************************************
  * Name: twi_timeout
  *
@@ -1208,7 +1227,7 @@ struct i2c_dev_s *up_i2cinitialize(int bus)
 #ifdef CONFIG_SAMA5_TWI0
   if (bus == 0)
     {
-      /* Set up TWI2 register base address and IRQ number */
+      /* Set up TWI0 register base address and IRQ number */
 
       priv       = &g_twi0;
       priv->base = SAM_TWI0_VBASE;
@@ -1285,6 +1304,33 @@ struct i2c_dev_s *up_i2cinitialize(int bus)
       pid        = SAM_PID_TWI2;
     }
   else
+#endif
+#ifdef CONFIG_SAMA5_TWI3
+  if (bus == 3)
+    {
+      /* Set up TWI3 register base address and IRQ number */
+
+      priv       = &g_twi3;
+      priv->base = SAM_TWI3_VBASE;
+      priv->irq  = SAM_IRQ_TWI3;
+      priv->twi  = 3;
+
+      /* Configure PIO pins */
+
+      sam_configpio(PIO_TWI3_CK);
+      sam_configpio(PIO_TWI3_D);
+
+      /* Enable peripheral clocking */
+
+      sam_twi3_enableclk();
+
+      /* Select the interrupt handler, TWI frequency, and peripheral ID */
+
+      handler    = twi3_interrupt;
+      frequency  = CONFIG_SAMA5_TWI3_FREQUENCY;
+      pid        = SAM_PID_TWI3;
+    }
+  else
 #endif
     {
       irqrestore(flags);