Diff: nrf_gpiote.h

Revision:

0:de3e4a57ebe0

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nrf_gpiote.h	Tue Dec 08 11:58:59 2015 +0000
@@ -0,0 +1,153 @@
+/* Copyright (c) 2012 Nordic Semiconductor. All Rights Reserved.
+ *
+ * The information contained herein is property of Nordic Semiconductor ASA.
+ * Terms and conditions of usage are described in detail in NORDIC
+ * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
+ *
+ * Licensees are granted free, non-transferable use of the information. NO
+ * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
+ * the file.
+ *
+ */
+#ifndef NRF_GPIOTE_H__
+#define NRF_GPIOTE_H__
+
+#include "nrf.h"
+
+/**
+* @defgroup nrf_gpiote GPIOTE abstraction
+* @{
+* @ingroup nrf_drivers
+* @brief GPIOTE abstraction for configuration of channels.
+*/
+
+
+ /**
+ * @enum nrf_gpiote_polarity_t
+ * @brief Polarity for GPIOTE channel enumerator.
+ */
+typedef enum
+{
+  NRF_GPIOTE_POLARITY_LOTOHI = GPIOTE_CONFIG_POLARITY_LoToHi,       ///<  Low to high
+  NRF_GPIOTE_POLARITY_HITOLO = GPIOTE_CONFIG_POLARITY_HiToLo,       ///<  High to low
+  NRF_GPIOTE_POLARITY_TOGGLE = GPIOTE_CONFIG_POLARITY_Toggle        ///<  Toggle
+} nrf_gpiote_polarity_t;
+
+
+ /**
+ * @enum nrf_gpiote_outinit_t
+ * @brief Initial output value for GPIOTE channel enumerator.
+ */
+typedef enum
+{
+  NRF_GPIOTE_INITIAL_VALUE_LOW  = GPIOTE_CONFIG_OUTINIT_Low,       ///<  Low to high
+  NRF_GPIOTE_INITIAL_VALUE_HIGH = GPIOTE_CONFIG_OUTINIT_High       ///<  High to low
+} nrf_gpiote_outinit_t;
+
+
+/**
+ * @brief Function for configuring GPIOTE channel as output, setting the properly desired output level.
+ *
+ *
+ * @param channel_number specifies the GPIOTE channel [0:3] to configure as an output channel.
+ * @param pin_number specifies the pin number [0:30] to use in the GPIOTE channel.
+ * @param polarity specifies the desired polarity in the output GPIOTE channel.
+ * @param initial_value specifies the initial value of the GPIOTE channel input after the channel configuration.
+ */
+static __INLINE void nrf_gpiote_task_config(uint32_t channel_number, uint32_t pin_number, nrf_gpiote_polarity_t polarity, nrf_gpiote_outinit_t initial_value)
+{
+    /* Check if the output desired is high or low */
+    if (initial_value == NRF_GPIOTE_INITIAL_VALUE_LOW)
+    {
+        /* Workaround for the OUTINIT PAN. When nrf_gpiote_task_config() is called a glitch happens
+        on the GPIO if the GPIO in question is already assigned to GPIOTE and the pin is in the 
+        correct state in GPIOTE but not in the OUT register. */
+        NRF_GPIO->OUTCLR = (1 << pin_number);
+        
+        /* Configure channel to Pin31, not connected to the pin, and configure as a tasks that will set it to proper level */
+        NRF_GPIOTE->CONFIG[channel_number] = (GPIOTE_CONFIG_MODE_Task       << GPIOTE_CONFIG_MODE_Pos)     |
+                                             (31UL                          << GPIOTE_CONFIG_PSEL_Pos)     |
+                                             (GPIOTE_CONFIG_POLARITY_HiToLo << GPIOTE_CONFIG_POLARITY_Pos);                                    
+    } 
+    else 
+    {
+        /* Workaround for the OUTINIT PAN. When nrf_gpiote_task_config() is called a glitch happens
+        on the GPIO if the GPIO in question is already assigned to GPIOTE and the pin is in the 
+        correct state in GPIOTE but not in the OUT register. */
+        NRF_GPIO->OUTSET = (1 << pin_number);
+        
+        /* Configure channel to Pin31, not connected to the pin, and configure as a tasks that will set it to proper level */
+        NRF_GPIOTE->CONFIG[channel_number] = (GPIOTE_CONFIG_MODE_Task       << GPIOTE_CONFIG_MODE_Pos)     |
+                                             (31UL                          << GPIOTE_CONFIG_PSEL_Pos)     |
+                                             (GPIOTE_CONFIG_POLARITY_LoToHi << GPIOTE_CONFIG_POLARITY_Pos);
+    }
+
+    /* Three NOPs are required to make sure configuration is written before setting tasks or getting events */
+    __NOP();
+    __NOP();
+    __NOP(); 
+
+    /* Launch the task to take the GPIOTE channel output to the desired level */
+    NRF_GPIOTE->TASKS_OUT[channel_number] = 1;
+    
+
+    /* Finally configure the channel as the caller expects. If OUTINIT works, the channel is configured properly. 
+       If it does not, the channel output inheritance sets the proper level. */
+    NRF_GPIOTE->CONFIG[channel_number] = (GPIOTE_CONFIG_MODE_Task << GPIOTE_CONFIG_MODE_Pos)     |
+                                         ((uint32_t)pin_number    << GPIOTE_CONFIG_PSEL_Pos)     |
+                                         ((uint32_t)polarity      << GPIOTE_CONFIG_POLARITY_Pos) |
+                                         ((uint32_t)initial_value << GPIOTE_CONFIG_OUTINIT_Pos);
+
+    /* Three NOPs are required to make sure configuration is written before setting tasks or getting events */
+    __NOP();
+    __NOP();
+    __NOP(); 
+}
+
+/**
+ * @brief Function for configuring GPIOTE channel as input, automatically clearing an event that appears in some cases under configuration.
+ *
+ * Note that when configuring the channel as input an event might be triggered. Care of disabling interrupts
+ * for that channel is left to the user.
+ *
+ * @param channel_number specifies the GPIOTE channel [0:3] to configure as an input channel.
+ * @param pin_number specifies the pin number [0:30] to use in the GPIOTE channel.
+ * @param polarity specifies the desired polarity in the output GPIOTE channel.
+ */
+static __INLINE void nrf_gpiote_event_config(uint32_t channel_number, uint32_t pin_number, nrf_gpiote_polarity_t polarity)
+{   
+    /* Configure the channel as the caller expects */
+    NRF_GPIOTE->CONFIG[channel_number] = (GPIOTE_CONFIG_MODE_Event << GPIOTE_CONFIG_MODE_Pos)     |
+                                         ((uint32_t)pin_number     << GPIOTE_CONFIG_PSEL_Pos)     |
+                                         ((uint32_t)polarity       << GPIOTE_CONFIG_POLARITY_Pos);
+
+    /* Three NOPs are required to make sure configuration is written before setting tasks or getting events */
+    __NOP();
+    __NOP();
+    __NOP();
+    
+    /* Clear the event that appears in some cases */
+    NRF_GPIOTE->EVENTS_IN[channel_number] = 0; 
+}
+
+
+/**
+ * @brief Function for unconfiguring GPIOTE channel.
+ *
+ *
+ * Note that when unconfiguring the channel, the pin is configured as GPIO PIN_CNF configuration.
+ *
+ * @param channel_number specifies the GPIOTE channel [0:3] to unconfigure.
+ */
+static __INLINE void nrf_gpiote_unconfig(uint32_t channel_number)
+{   
+    /* Unonfigure the channel as the caller expects */
+    NRF_GPIOTE->CONFIG[channel_number] = (GPIOTE_CONFIG_MODE_Disabled   << GPIOTE_CONFIG_MODE_Pos) |
+                                         (31UL                          << GPIOTE_CONFIG_PSEL_Pos) |
+                                         (GPIOTE_CONFIG_POLARITY_Toggle << GPIOTE_CONFIG_POLARITY_Pos);
+}
+
+
+/** @} */
+
+#endif