Diff: targets/hal/TARGET_Atmel/TARGET_SAM21/drivers/sercom/sercom.c

Revision:

613:bc40b8d2aec4

Parent:

612:fba1c7dc54c0

Child:

614:9d86c2ae5de0

--- a/targets/hal/TARGET_Atmel/TARGET_SAM21/drivers/sercom/sercom.c	Tue Aug 18 15:00:09 2015 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,251 +0,0 @@
-#include "sercom.h"
-
-#define SHIFT 32
-#define BAUD_INT_MAX   8192
-#define BAUD_FP_MAX     8
-
-#if !defined(__DOXYGEN__)
-/**
- * \internal Configuration structure to save current gclk status.
- */
-struct _sercom_conf {
-    /* Status of gclk generator initialization. */
-    bool generator_is_set;
-    /* Sercom gclk generator used. */
-    enum gclk_generator generator_source;
-};
-
-static struct _sercom_conf _sercom_config;
-
-
-/**
- * \internal Calculate 64 bit division, ref can be found in
- * http://en.wikipedia.org/wiki/Division_algorithm#Long_division
- */
-static uint64_t long_division(uint64_t n, uint64_t d)
-{
-    int32_t i;
-    uint64_t q = 0, r = 0, bit_shift;
-    for (i = 63; i >= 0; i--) {
-        bit_shift = (uint64_t)1 << i;
-
-        r = r << 1;
-
-        if (n & bit_shift) {
-            r |= 0x01;
-        }
-
-        if (r >= d) {
-            r = r - d;
-            q |= bit_shift;
-        }
-    }
-
-    return q;
-}
-
-/**
- * \internal Calculate synchronous baudrate value (SPI/UART)
- */
-enum status_code _sercom_get_sync_baud_val(
-    const uint32_t baudrate,
-    const uint32_t external_clock,
-    uint16_t *const baudvalue)
-{
-    /* Baud value variable */
-    uint16_t baud_calculated = 0;
-    uint32_t clock_value = external_clock;
-
-
-    /* Check if baudrate is outside of valid range. */
-    if (baudrate > (external_clock / 2)) {
-        /* Return with error code */
-        return STATUS_ERR_BAUDRATE_UNAVAILABLE;
-    }
-
-    /* Calculate BAUD value from clock frequency and baudrate */
-    clock_value = external_clock / 2;
-    while (clock_value >= baudrate) {
-        clock_value = clock_value - baudrate;
-        baud_calculated++;
-    }
-    baud_calculated = baud_calculated - 1;
-
-    /* Check if BAUD value is more than 255, which is maximum
-     * for synchronous mode */
-    if (baud_calculated > 0xFF) {
-        /* Return with an error code */
-        return STATUS_ERR_BAUDRATE_UNAVAILABLE;
-    } else {
-        *baudvalue = baud_calculated;
-        return STATUS_OK;
-    }
-}
-
-/**
- * \internal Calculate asynchronous baudrate value (UART)
-*/
-enum status_code _sercom_get_async_baud_val(
-    const uint32_t baudrate,
-    const uint32_t peripheral_clock,
-    uint16_t *const baudval,
-    enum sercom_asynchronous_operation_mode mode,
-    enum sercom_asynchronous_sample_num sample_num)
-{
-    /* Temporary variables  */
-    uint64_t ratio = 0;
-    uint64_t scale = 0;
-    uint64_t baud_calculated = 0;
-    uint8_t baud_fp;
-    uint32_t baud_int = 0;
-    uint64_t temp1, temp2;
-
-    /* Check if the baudrate is outside of valid range */
-    if ((baudrate * sample_num) > peripheral_clock) {
-        /* Return with error code */
-        return STATUS_ERR_BAUDRATE_UNAVAILABLE;
-    }
-
-    if(mode == SERCOM_ASYNC_OPERATION_MODE_ARITHMETIC) {
-        /* Calculate the BAUD value */
-        temp1 = ((sample_num * (uint64_t)baudrate) << SHIFT);
-        ratio = long_division(temp1, peripheral_clock);
-        scale = ((uint64_t)1 << SHIFT) - ratio;
-        baud_calculated = (65536 * scale) >> SHIFT;
-    } else if(mode == SERCOM_ASYNC_OPERATION_MODE_FRACTIONAL) {
-        for(baud_fp = 0; baud_fp < BAUD_FP_MAX; baud_fp++) {
-            temp1 = BAUD_FP_MAX * (uint64_t)peripheral_clock;
-            temp2 = ((uint64_t)baudrate * sample_num);
-            baud_int = long_division(temp1, temp2);
-            baud_int -= baud_fp;
-            baud_int = baud_int / BAUD_FP_MAX;
-            if(baud_int < BAUD_INT_MAX) {
-                break;
-            }
-        }
-        if(baud_fp == BAUD_FP_MAX) {
-            return STATUS_ERR_BAUDRATE_UNAVAILABLE;
-        }
-        baud_calculated = baud_int | (baud_fp << 13);
-    }
-
-    *baudval = baud_calculated;
-    return STATUS_OK;
-}
-#endif
-
-/**
- * \brief Set GCLK channel to generator.
- *
- * This will set the appropriate GCLK channel to the requested GCLK generator.
- * This will set the generator for all SERCOM instances, and the user will thus
- * only be able to set the same generator that has previously been set, if any.
- *
- * After the generator has been set the first time, the generator can be changed
- * using the \c force_change flag.
- *
- * \param[in]  generator_source The generator to use for SERCOM.
- * \param[in]  force_change     Force change the generator.
- *
- * \return Status code indicating the GCLK generator change operation.
- * \retval STATUS_OK                       If the generator update request was
- *                                         successful.
- * \retval STATUS_ERR_ALREADY_INITIALIZED  If a generator was already configured
- *                                         and the new configuration was not
- *                                         forced.
- */
-enum status_code sercom_set_gclk_generator(
-    const enum gclk_generator generator_source,
-    const bool force_change)
-{
-    /* Check if valid option. */
-    if (!_sercom_config.generator_is_set || force_change) {
-        /* Create and fill a GCLK configuration structure for the new config. */
-        struct system_gclk_chan_config gclk_chan_conf;
-        system_gclk_chan_get_config_defaults(&gclk_chan_conf);
-        gclk_chan_conf.source_generator = generator_source;
-        system_gclk_chan_set_config(SERCOM_GCLK_ID, &gclk_chan_conf);
-        system_gclk_chan_enable(SERCOM_GCLK_ID);
-
-        /* Save config. */
-        _sercom_config.generator_source = generator_source;
-        _sercom_config.generator_is_set = true;
-
-        return STATUS_OK;
-    } else if (generator_source == _sercom_config.generator_source) {
-        /* Return status OK if same config. */
-        return STATUS_OK;
-    }
-
-    /* Return invalid config to already initialized GCLK. */
-    return STATUS_ERR_ALREADY_INITIALIZED;
-}
-
-/** \internal
- * Creates a switch statement case entry to convert a SERCOM instance and pad
- * index to the default SERCOM pad MUX setting.
- */
-#define _SERCOM_PAD_DEFAULTS_CASE(n, pad) \
-		case (uintptr_t)SERCOM##n: \
-			switch (pad) { \
-				case 0: \
-					return SERCOM##n##_PAD0_DEFAULT; \
-				case 1: \
-					return SERCOM##n##_PAD1_DEFAULT; \
-				case 2: \
-					return SERCOM##n##_PAD2_DEFAULT; \
-				case 3: \
-					return SERCOM##n##_PAD3_DEFAULT; \
-			} \
-			break;
-
-/**
- * \internal Gets the default PAD pinout for a given SERCOM.
- *
- * Returns the pinmux settings for the given SERCOM and pad. This is used
- * for default configuration of pins.
- *
- * \param[in]  sercom_module   Pointer to the SERCOM module
- * \param[in]  pad             PAD to get default pinout for
- *
- * \returns The default pinmux for the given SERCOM instance and PAD
- *
- */
-uint32_t _sercom_get_default_pad(
-    Sercom *const sercom_module,
-    const uint8_t pad)
-{
-    switch ((uintptr_t)sercom_module) {
-            /* Auto-generate a lookup table for the default SERCOM pad defaults */
-            MREPEAT(SERCOM_INST_NUM, _SERCOM_PAD_DEFAULTS_CASE, pad)
-    }
-
-    Assert(false);
-    return 0;
-}
-
-/**
- * \internal
- * Find index of given instance.
- *
- * \param[in] sercom_instance  Instance pointer.
- *
- * \return Index of given instance.
- */
-uint8_t _sercom_get_sercom_inst_index(
-    Sercom *const sercom_instance)
-{
-    /* Save all available SERCOM instances for compare. */
-    Sercom *sercom_instances[SERCOM_INST_NUM] = SERCOM_INSTS;
-
-    /* Find index for sercom instance. */
-    for (uint32_t i = 0; i < SERCOM_INST_NUM; i++) {
-        if ((uintptr_t)sercom_instance == (uintptr_t)sercom_instances[i]) {
-            return i;
-        }
-    }
-
-    /* Invalid data given. */
-    Assert(false);
-    return 0;
-}