File content as of revision 172:65be27845400:

/* 
 * Copyright (c) 2015 Nordic Semiconductor ASA
 * All rights reserved.
 * 
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 *   4. This software, with or without modification, must only be used with a 
 *      Nordic Semiconductor ASA integrated circuit.
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#ifndef NRF_PDM_H_
#define NRF_PDM_H_

/**
 * @defgroup nrf_pdm_hal PDM HAL
 * @{
 * @ingroup nrf_pdm
 *
 * @brief @tagAPI52 Hardware abstraction layer for accessing the pulse density modulation (PDM) peripheral.
 */

#include <stdbool.h>
#include <stddef.h>
#include "nrf.h"
#include "nrf_assert.h"


#define NRF_PDM_GAIN_MINIMUM  0x00
#define NRF_PDM_GAIN_DEFAULT  0x28
#define NRF_PDM_GAIN_MAXIMUM  0x50

typedef uint8_t nrf_pdm_gain_t;


/**
 * @brief PDM tasks.
 */
typedef enum /*lint -save -e30 -esym(628,__INTADDR__) */
{
    NRF_PDM_TASK_START           = offsetof(NRF_PDM_Type, TASKS_START),           ///< Starts continuous PDM transfer.
    NRF_PDM_TASK_STOP            = offsetof(NRF_PDM_Type, TASKS_STOP)             ///< Stops PDM transfer.
} nrf_pdm_task_t;


/**
 * @brief PDM events.
 */
typedef enum /*lint -save -e30 -esym(628,__INTADDR__) */
{
    NRF_PDM_EVENT_STARTED       = offsetof(NRF_PDM_Type, EVENTS_STARTED),       ///< PDM transfer has started.
    NRF_PDM_EVENT_STOPPED       = offsetof(NRF_PDM_Type, EVENTS_STOPPED),       ///< PDM transfer has finished.
    NRF_PDM_EVENT_END           = offsetof(NRF_PDM_Type, EVENTS_END)            ///< The PDM has written the last sample specified by SAMPLE.MAXCNT (or the last sample after a STOP task has been received) to Data RAM.
} nrf_pdm_event_t;


/**
 * @brief PDM interrupt masks.
 */
typedef enum
{
    NRF_PDM_INT_STARTED = PDM_INTENSET_STARTED_Msk,   ///< Interrupt on EVENTS_STARTED event.
    NRF_PDM_INT_STOPPED = PDM_INTENSET_STOPPED_Msk,   ///< Interrupt on EVENTS_STOPPED event.
    NRF_PDM_INT_END     = PDM_INTENSET_END_Msk        ///< Interrupt on EVENTS_END event.
} nrf_pdm_int_mask_t;

/**
 * @brief PDM clock frequency.
 */
typedef enum
{
    NRF_PDM_FREQ_1000K = PDM_PDMCLKCTRL_FREQ_1000K,  ///< PDM_CLK = 1.000 MHz.
    NRF_PDM_FREQ_1032K = PDM_PDMCLKCTRL_FREQ_Default,  ///< PDM_CLK = 1.032 MHz.
    NRF_PDM_FREQ_1067K = PDM_PDMCLKCTRL_FREQ_1067K   ///< PDM_CLK = 1.067 MHz.
} nrf_pdm_freq_t;


/**
 * @brief PDM operation mode.
 */
typedef enum
{
    NRF_PDM_MODE_STEREO = PDM_MODE_OPERATION_Stereo,  ///< Sample and store one pair (Left + Right) of 16-bit samples per RAM word.
    NRF_PDM_MODE_MONO   = PDM_MODE_OPERATION_Mono     ///< Sample and store two successive Left samples (16 bit each) per RAM word.
} nrf_pdm_mode_t;


/**
 * @brief PDM sampling mode.
 */
typedef enum
{
    NRF_PDM_EDGE_LEFTFALLING = PDM_MODE_EDGE_LeftFalling,  ///< Left (or mono) is sampled on falling edge of PDM_CLK.
    NRF_PDM_EDGE_LEFTRISING  = PDM_MODE_EDGE_LeftRising    ///< Left (or mono) is sampled on rising edge of PDM_CLK.
} nrf_pdm_edge_t;


/**
 * @brief Function for triggering a PDM task.
 *
 * @param[in] pdm_task PDM task.
 */
__STATIC_INLINE void nrf_pdm_task_trigger(nrf_pdm_task_t pdm_task)
{
    *((volatile uint32_t *)((uint8_t *)NRF_PDM + (uint32_t)pdm_task)) = 0x1UL;
}


/**
 * @brief Function for getting the address of a PDM task register.
 *
 * @param[in] pdm_task PDM task.
 *
 * @return Address of the specified PDM task.
 */
__STATIC_INLINE uint32_t nrf_pdm_task_address_get(nrf_pdm_task_t pdm_task)
{
    return (uint32_t)((uint8_t *)NRF_PDM + (uint32_t)pdm_task);
}


/**
 * @brief Function for getting the state of a PDM event.
 *
 * @param[in] pdm_event PDM event.
 *
 * @return State of the specified PDM event.
 */
__STATIC_INLINE bool nrf_pdm_event_check(nrf_pdm_event_t pdm_event)
{
    return (bool)*(volatile uint32_t *)((uint8_t *)NRF_PDM + (uint32_t)pdm_event);
}


/**
 * @brief Function for clearing a PDM event.
 *
 * @param[in] pdm_event PDM event.
 */
__STATIC_INLINE void nrf_pdm_event_clear(nrf_pdm_event_t pdm_event)
{
    *((volatile uint32_t *)((uint8_t *)NRF_PDM + (uint32_t)pdm_event)) = 0x0UL;
}


/**
 * @brief Function for getting the address of a PDM event register.
 *
 * @param[in] pdm_event PDM event.
 *
 * @return Address of the specified PDM event.
 */
__STATIC_INLINE volatile uint32_t * nrf_pdm_event_address_get(nrf_pdm_event_t pdm_event)
{
    return (volatile uint32_t *)((uint8_t *)NRF_PDM + (uint32_t)pdm_event);
}


/**
 * @brief Function for enabling PDM interrupts.
 *
 * @param[in] pdm_int_mask Interrupts to enable.
 */
__STATIC_INLINE void nrf_pdm_int_enable(uint32_t pdm_int_mask)
{
    NRF_PDM->INTENSET = pdm_int_mask;
}


/**
 * @brief Function for retrieving the state of PDM interrupts.
 *
 * @param[in] pdm_int_mask Interrupts to check.
 *
 * @retval true  If all specified interrupts are enabled.
 * @retval false If at least one of the given interrupts is not enabled.
 */
__STATIC_INLINE bool nrf_pdm_int_enable_check(uint32_t pdm_int_mask)
{
    return (bool)(NRF_PDM->INTENSET & pdm_int_mask);
}


/**
 * @brief Function for disabling interrupts.
 *
 * @param pdm_int_mask Interrupts to disable.
 */
__STATIC_INLINE void nrf_pdm_int_disable(uint32_t pdm_int_mask)
{
    NRF_PDM->INTENCLR = pdm_int_mask;
}


/**
 * @brief Function for enabling the PDM peripheral.
 *
 * The PDM peripheral must be enabled before use.
 */
__STATIC_INLINE void nrf_pdm_enable(void)
{
    NRF_PDM->ENABLE = (PDM_ENABLE_ENABLE_Enabled << PDM_ENABLE_ENABLE_Pos);
}


/**
 * @brief Function for disabling the PDM peripheral.
 */
__STATIC_INLINE void nrf_pdm_disable(void)
{
    NRF_PDM->ENABLE = (PDM_ENABLE_ENABLE_Disabled << PDM_ENABLE_ENABLE_Pos);
}


/**
 * @brief Function for checking if the PDM peripheral is enabled.
 *
 * @retval true  If the PDM peripheral is enabled.
 * @retval false If the PDM peripheral is not enabled.
 */
__STATIC_INLINE bool nrf_pdm_enable_check(void)
{
    return (NRF_PDM->ENABLE == (PDM_ENABLE_ENABLE_Enabled << PDM_ENABLE_ENABLE_Pos));
}


/**
 * @brief Function for setting the PDM operation mode.
 *
 * @param[in] pdm_mode PDM operation mode.
 * @param[in] pdm_edge PDM sampling mode.
 */
__STATIC_INLINE void nrf_pdm_mode_set(nrf_pdm_mode_t pdm_mode, nrf_pdm_edge_t pdm_edge)
{
    NRF_PDM->MODE = ((pdm_mode << PDM_MODE_OPERATION_Pos) & PDM_MODE_OPERATION_Msk)
                    | ((pdm_edge << PDM_MODE_EDGE_Pos) & PDM_MODE_EDGE_Msk);
}


/**
 * @brief Function for getting the PDM operation mode.
 *
 * @param[out] p_pdm_mode PDM operation mode.
 * @param[out] p_pdm_edge PDM sampling mode.
 */
__STATIC_INLINE void nrf_pdm_mode_get(nrf_pdm_mode_t * p_pdm_mode, nrf_pdm_edge_t * p_pdm_edge)
{
    uint32_t mode = NRF_PDM->MODE;
    *p_pdm_mode = (nrf_pdm_mode_t)((mode & PDM_MODE_OPERATION_Msk ) >> PDM_MODE_OPERATION_Pos);
    *p_pdm_edge = (nrf_pdm_edge_t)((mode & PDM_MODE_EDGE_Msk ) >> PDM_MODE_EDGE_Pos);
}


/**
 * @brief Function for setting the PDM clock frequency.
 *
 * @param[in] pdm_freq PDM clock frequency.
 */
__STATIC_INLINE void nrf_pdm_clock_set(nrf_pdm_freq_t pdm_freq)
{
    NRF_PDM->PDMCLKCTRL = ((pdm_freq << PDM_PDMCLKCTRL_FREQ_Pos) & PDM_PDMCLKCTRL_FREQ_Msk);
}


/**
 * @brief Function for getting the PDM clock frequency.
 */
__STATIC_INLINE nrf_pdm_freq_t nrf_pdm_clock_get(void)
{
     return (nrf_pdm_freq_t) ((NRF_PDM->PDMCLKCTRL << PDM_PDMCLKCTRL_FREQ_Pos) & PDM_PDMCLKCTRL_FREQ_Msk);
}


/**
 * @brief Function for setting up the PDM pins.
 *
 * @param[in] psel_clk CLK pin number.
 * @param[in] psel_din DIN pin number.
 */
__STATIC_INLINE void nrf_pdm_psel_connect(uint32_t psel_clk, uint32_t psel_din)
{
    NRF_PDM->PSEL.CLK = ((psel_clk << PDM_PSEL_CLK_PIN_Pos) & PDM_PSEL_CLK_PIN_Msk)
            | ((PDM_PSEL_CLK_CONNECT_Connected << PDM_PSEL_CLK_CONNECT_Pos) & PDM_PSEL_CLK_CONNECT_Msk);
    NRF_PDM->PSEL.DIN = ((psel_din << PDM_PSEL_DIN_PIN_Pos) & PDM_PSEL_DIN_PIN_Msk)
            | ((PDM_PSEL_DIN_CONNECT_Connected << PDM_PSEL_CLK_CONNECT_Pos) & PDM_PSEL_DIN_CONNECT_Msk);
}

/**
 * @brief Function for disconnecting the PDM pins.
 */
__STATIC_INLINE void nrf_pdm_psel_disconnect()
{
    NRF_PDM->PSEL.CLK = ((PDM_PSEL_CLK_CONNECT_Disconnected << PDM_PSEL_CLK_CONNECT_Pos) 
                         & PDM_PSEL_CLK_CONNECT_Msk);
    NRF_PDM->PSEL.DIN = ((PDM_PSEL_DIN_CONNECT_Disconnected << PDM_PSEL_DIN_CONNECT_Pos) 
                         & PDM_PSEL_DIN_CONNECT_Msk);
}


/**
 * @brief Function for setting the PDM gain.
 *
 * @param[in] gain_l Left channel gain.
 * @param[in] gain_r Right channel gain.
 */
__STATIC_INLINE void nrf_pdm_gain_set(nrf_pdm_gain_t gain_l, nrf_pdm_gain_t gain_r)
{
    NRF_PDM->GAINL = gain_l;
    NRF_PDM->GAINR = gain_r;
}


/**
 * @brief Function for getting the PDM gain.
 *
 * @param[out] p_gain_l Left channel gain.
 * @param[out] p_gain_r Right channel gain.
 */
__STATIC_INLINE void nrf_pdm_gain_get(nrf_pdm_gain_t * p_gain_l, nrf_pdm_gain_t * p_gain_r)
{
    *p_gain_l = NRF_PDM->GAINL;
    *p_gain_r = NRF_PDM->GAINR;
}


/**
 * @brief Function for setting the PDM sample buffer.
 *
 * @param[in] p_buffer Pointer to the RAM address where samples should be written with EasyDMA.
 * @param[in] num    Number of samples to allocate memory for in EasyDMA mode.
 *
 * The amount of allocated RAM depends on the operation mode.
 * - For stereo mode: N 32-bit words.
 * - For mono mode: Ceil(N/2) 32-bit words.
 */
__STATIC_INLINE void nrf_pdm_buffer_set(uint32_t * p_buffer, uint32_t num)
{
    NRF_PDM->SAMPLE.PTR = (uint32_t)p_buffer;
    NRF_PDM->SAMPLE.MAXCNT = num;
}

/**
 * @brief Function for getting the current PDM sample buffer address.
 *
 * @return Pointer to the current sample buffer.
 */
__STATIC_INLINE uint32_t * nrf_pdm_buffer_get()
{
    return (uint32_t *)NRF_PDM->SAMPLE.PTR;
}


/**
 *@}
 **/

#endif /* NRF_PDM_H_ */