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cpu/sam21_common: add a few typedefs for SERCOM

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A generic function is added to initialize a SERCOM.

Notice that uart_conf_t was expanded with pad settings, but it isn't used
yet.
This commit is contained in:
Kees Bakker 2016-07-31 22:20:58 +02:00
parent 8644b5f7a0
commit 4ad3313ae5
3 changed files with 95 additions and 3 deletions
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73
cpu/sam21_common/include/periph_cpu_common.h
View File

@ -86,13 +86,82 @@ typedef enum {
GPIO_MUX_H = 0x7, /**< select peripheral function H */
} gpio_mux_t;
/**
* @brief Possible pad selections for SERCOM RX (inspired by Arduino)
*/
typedef enum {
SERCOM_RX_PAD_0 = 0x0, /**< select pad 0 */
SERCOM_RX_PAD_1 = 0x1, /**< select pad 1 */
SERCOM_RX_PAD_2 = 0x2, /**< select pad 2 */
SERCOM_RX_PAD_3 = 0x3, /**< select pad 3 */
} sercom_rxpad_t;
/**
* @brief Possible pad selections for SERCOM UART TX (inspired by Arduino)
*/
typedef enum {
UART_TX_PAD_0 = 0x0, /**< select pad 0, only UART */
UART_TX_PAD_2 = 0x1, /**< select pad 2, only UART */
UART_TX_RTS_CTS_PAD_0_2_3 = 0x2, /**< select pad 0, 2 and 3, only UART, TX on PAD0, RTS on PAD2 and CTS on PAD3 */
} sercom_uart_txpad_t;
/**
* @brief Possible pad selections for SERCOM SPI output (inspired by Arduino)
*/
typedef enum {
SPI_PAD_0_SCK_1 = 0, /**< select pad 0, SCK pad1, only SPI */
SPI_PAD_2_SCK_3 = 1, /**< select pad 2, SCK pad3, only SPI */
SPI_PAD_3_SCK_1 = 2, /**< select pad 3, SCK pad1, only SPI */
SPI_PAD_0_SCK_3 = 3, /**< select pad 0, SCK pad3, only SPI */
} sercom_spi_txpad_t;
/**
* @brief Possible selections for SERCOM SPI data size (inspired by Arduino)
*/
typedef enum
{
SPI_CHAR_SIZE_8_BITS = 0x0ul,
SPI_CHAR_SIZE_9_BITS = 0x1ul,
} sercom_spi_charsize_t;
/**
* @brief Possible selections for SERCOM data (bit) order (inspired by Arduino)
*/
typedef enum
{
MSB_FIRST = 0,
LSB_FIRST = 1,
} sercom_data_order_t;
/**
* @brief Possible selections for SERCOM SPI clock mode (inspired by Arduino)
*/
typedef enum
{
SERCOM_SPI_MODE_0 = 0, // CPOL : 0 | CPHA : 0
SERCOM_SPI_MODE_1 = 1, // CPOL : 0 | CPHA : 1
SERCOM_SPI_MODE_2 = 2, // CPOL : 1 | CPHA : 0
SERCOM_SPI_MODE_3 = 3, // CPOL : 1 | CPHA : 1
} sercom_spi_clockmode_t;
/**
* @brief Set up alternate function (PMUX setting) for a PORT pin
*
* @param[in] dev Pin to set the multiplexing for
* @param[in] pin Pin to set the multiplexing for
* @param[in] mux Mux value
*/
void gpio_init_mux(gpio_t dev, gpio_mux_t mux);
void gpio_init_mux(gpio_t pin, gpio_mux_t mux);
/**
* @brief Set up PORT pin for SERCOM usage
*
* This function initializes the pin for SERCOM usage. It is derived
* from Arduino's pinPeripheral() in wiring_private.c
*
* @param[in] pin Pin to set the multiplexing for
* @param[in] mux Mux value
*/
void gpio_init_sercom(gpio_t pin, gpio_mux_t mux);
#ifdef __cplusplus
}

4
cpu/samd21/include/periph_cpu.h
View File

@ -38,7 +38,7 @@ enum {
* @brief Generate GPIO mode bitfields
*
* We use 3 bit to determine the pin functions:
* - bit 0: PU or PU
* - bit 0: PD(0) or PU(1)
* - bit 1: input enable
* - bit 2: pull enable
*/
@ -86,6 +86,8 @@ typedef struct {
gpio_t rx_pin; /**< pin used for RX */
gpio_t tx_pin; /**< pin used for TX */
gpio_mux_t mux; /**< alternative function for pins */
sercom_rxpad_t rx_pad; /**< pad selection for RX */
sercom_uart_txpad_t tx_pad; /**< pad selection for TX */
} uart_conf_t;
/**

21
cpu/samd21/periph/gpio.c
View File

@ -120,6 +120,27 @@ int gpio_init(gpio_t pin, gpio_mode_t mode)
return 0;
}
void gpio_init_sercom(gpio_t pin, gpio_mux_t mux)
{
PortGroup* port = _port(pin);
int pin_pos = _pin_pos(pin);
uint32_t temp;
if ( (pin_pos & 1) ) { // is pin odd?
// Get whole current setup for both odd and even pins and remove odd one
temp = port->PMUX[pin_pos >> 1].reg & PORT_PMUX_PMUXE(0xF);
// Set new muxing
port->PMUX[pin_pos >> 1].reg = temp | PORT_PMUX_PMUXO(mux);
} else {
// Get whole current setup for both odd and even pins and remove even one
temp = port->PMUX[pin_pos >> 1].reg & PORT_PMUX_PMUXO(0xF);
// Set new muxing
port->PMUX[pin_pos >> 1].reg = temp | PORT_PMUX_PMUXE(mux);
}
// Enable port mux
port->PINCFG[pin_pos].reg |= PORT_PINCFG_PMUXEN;
}
int gpio_init_int(gpio_t pin, gpio_mode_t mode, gpio_flank_t flank,
gpio_cb_t cb, void *arg)
{