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/*
* Copyright (c) 2018 Justin Watson
* Copyright (c) 2016 Piotr Mienkowski
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT atmel_sam_usart
/** @file
* @brief USART driver for Atmel SAM MCU family.
*
* Note:
* - Only basic USART features sufficient to support printf functionality
* are currently implemented.
*/
#include <errno.h>
#include <sys/__assert.h>
#include <device.h>
#include <init.h>
#include <soc.h>
#include <drivers/uart.h>
/* Device constant configuration parameters */
struct usart_sam_dev_cfg {
Usart *regs;
uint32_t periph_id;
struct soc_gpio_pin pin_rx;
struct soc_gpio_pin pin_tx;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
uart_irq_config_func_t irq_config_func;
#endif
};
/* Device run time data */
struct usart_sam_dev_data {
uint32_t baud_rate;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
uart_irq_callback_user_data_t irq_cb; /* Interrupt Callback */
void *cb_data; /* Interrupt Callback Arg */
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
};
#define DEV_CFG(dev) \
((const struct usart_sam_dev_cfg *const)(dev)->config)
#define DEV_DATA(dev) \
((struct usart_sam_dev_data *const)(dev)->data)
static int baudrate_set(Usart *const usart, uint32_t baudrate,
uint32_t mck_freq_hz);
static int usart_sam_init(const struct device *dev)
{
int retval;
const struct usart_sam_dev_cfg *const cfg = DEV_CFG(dev);
struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);
Usart *const usart = cfg->regs;
/* Enable USART clock in PMC */
soc_pmc_peripheral_enable(cfg->periph_id);
/* Connect pins to the peripheral */
soc_gpio_configure(&cfg->pin_rx);
soc_gpio_configure(&cfg->pin_tx);
/* Reset and disable USART */
usart->US_CR = US_CR_RSTRX | US_CR_RSTTX
| US_CR_RXDIS | US_CR_TXDIS | US_CR_RSTSTA;
/* Disable Interrupts */
usart->US_IDR = 0xFFFFFFFF;
/* 8 bits of data, no parity, 1 stop bit in normal mode */
usart->US_MR = US_MR_NBSTOP_1_BIT
| US_MR_PAR_NO
| US_MR_CHRL_8_BIT
| US_MR_USCLKS_MCK
| US_MR_CHMODE_NORMAL;
/* Set baud rate */
retval = baudrate_set(usart, dev_data->baud_rate,
SOC_ATMEL_SAM_MCK_FREQ_HZ);
if (retval != 0) {
return retval;
}
/* Enable receiver and transmitter */
usart->US_CR = US_CR_RXEN | US_CR_TXEN;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
cfg->irq_config_func(dev);
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
return 0;
}
static int usart_sam_poll_in(const struct device *dev, unsigned char *c)
{
Usart *const usart = DEV_CFG(dev)->regs;
if (!(usart->US_CSR & US_CSR_RXRDY)) {
return -EBUSY;
}
/* got a character */
*c = (unsigned char)usart->US_RHR;
return 0;
}
static void usart_sam_poll_out(const struct device *dev, unsigned char c)
{
Usart *const usart = DEV_CFG(dev)->regs;
/* Wait for transmitter to be ready */
while (!(usart->US_CSR & US_CSR_TXRDY)) {
}
/* send a character */
usart->US_THR = (uint32_t)c;
}
static int usart_sam_err_check(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
int errors = 0;
if (usart->US_CSR & US_CSR_OVRE) {
errors |= UART_ERROR_OVERRUN;
}
if (usart->US_CSR & US_CSR_PARE) {
errors |= UART_ERROR_PARITY;
}
if (usart->US_CSR & US_CSR_FRAME) {
errors |= UART_ERROR_FRAMING;
}
return errors;
}
static int baudrate_set(Usart *const usart, uint32_t baudrate,
uint32_t mck_freq_hz)
{
uint32_t divisor;
__ASSERT(baudrate,
"baud rate has to be bigger than 0");
__ASSERT(mck_freq_hz/16U >= baudrate,
"MCK frequency is too small to set required baud rate");
divisor = mck_freq_hz / 16U / baudrate;
if (divisor > 0xFFFF) {
return -EINVAL;
}
usart->US_BRGR = US_BRGR_CD(divisor);
return 0;
}
#if CONFIG_UART_INTERRUPT_DRIVEN
static int usart_sam_fifo_fill(const struct device *dev,
const uint8_t *tx_data,
int size)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
/* Wait for transmitter to be ready. */
while ((usart->US_CSR & US_CSR_TXRDY) == 0) {
}
usart->US_THR = *tx_data;
return 1;
}
static int usart_sam_fifo_read(const struct device *dev, uint8_t *rx_data,
const int size)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
int bytes_read;
bytes_read = 0;
while (bytes_read < size) {
if (usart->US_CSR & US_CSR_RXRDY) {
rx_data[bytes_read] = usart->US_RHR;
bytes_read++;
} else {
break;
}
}
return bytes_read;
}
static void usart_sam_irq_tx_enable(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
usart->US_IER = US_IER_TXRDY;
}
static void usart_sam_irq_tx_disable(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
usart->US_IDR = US_IDR_TXRDY;
}
static int usart_sam_irq_tx_ready(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
return (usart->US_CSR & US_CSR_TXRDY);
}
static void usart_sam_irq_rx_enable(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
usart->US_IER = US_IER_RXRDY;
}
static void usart_sam_irq_rx_disable(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
usart->US_IDR = US_IDR_RXRDY;
}
static int usart_sam_irq_tx_complete(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
return !(usart->US_CSR & US_CSR_TXRDY);
}
static int usart_sam_irq_rx_ready(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
return (usart->US_CSR & US_CSR_RXRDY);
}
static void usart_sam_irq_err_enable(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
usart->US_IER = US_IER_OVRE | US_IER_FRAME | US_IER_PARE;
}
static void usart_sam_irq_err_disable(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
usart->US_IDR = US_IDR_OVRE | US_IDR_FRAME | US_IDR_PARE;
}
static int usart_sam_irq_is_pending(const struct device *dev)
{
volatile Usart * const usart = DEV_CFG(dev)->regs;
return (usart->US_IMR & (US_IMR_TXRDY | US_IMR_RXRDY)) &
(usart->US_CSR & (US_CSR_TXRDY | US_CSR_RXRDY));
}
static int usart_sam_irq_update(const struct device *dev)
{
ARG_UNUSED(dev);
return 1;
}
static void usart_sam_irq_callback_set(const struct device *dev,
uart_irq_callback_user_data_t cb,
void *cb_data)
{
struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);
dev_data->irq_cb = cb;
dev_data->cb_data = cb_data;
}
static void usart_sam_isr(const struct device *dev)
{
struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);
if (dev_data->irq_cb) {
dev_data->irq_cb(dev, dev_data->cb_data);
}
}
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
static const struct uart_driver_api usart_sam_driver_api = {
.poll_in = usart_sam_poll_in,
.poll_out = usart_sam_poll_out,
.err_check = usart_sam_err_check,
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.fifo_fill = usart_sam_fifo_fill,
.fifo_read = usart_sam_fifo_read,
.irq_tx_enable = usart_sam_irq_tx_enable,
.irq_tx_disable = usart_sam_irq_tx_disable,
.irq_tx_ready = usart_sam_irq_tx_ready,
.irq_rx_enable = usart_sam_irq_rx_enable,
.irq_rx_disable = usart_sam_irq_rx_disable,
.irq_tx_complete = usart_sam_irq_tx_complete,
.irq_rx_ready = usart_sam_irq_rx_ready,
.irq_err_enable = usart_sam_irq_err_enable,
.irq_err_disable = usart_sam_irq_err_disable,
.irq_is_pending = usart_sam_irq_is_pending,
.irq_update = usart_sam_irq_update,
.irq_callback_set = usart_sam_irq_callback_set,
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
};
#define USART_SAM_DECLARE_CFG(n, IRQ_FUNC_INIT) \
static const struct usart_sam_dev_cfg usart##n##_sam_config = { \
.regs = (Usart *)DT_INST_REG_ADDR(n), \
.periph_id = DT_INST_PROP(n, peripheral_id), \
\
.pin_rx = ATMEL_SAM_DT_PIN(n, 0), \
.pin_tx = ATMEL_SAM_DT_PIN(n, 1), \
\
IRQ_FUNC_INIT \
}
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
#define USART_SAM_CONFIG_FUNC(n) \
static void usart##n##_sam_irq_config_func(const struct device *port) \
{ \
IRQ_CONNECT(DT_INST_IRQN(n), \
DT_INST_IRQ(n, priority), \
usart_sam_isr, \
DEVICE_GET(usart##n##_sam), 0); \
irq_enable(DT_INST_IRQN(n)); \
}
#define USART_SAM_IRQ_CFG_FUNC_INIT(n) \
.irq_config_func = usart##n##_sam_irq_config_func
#define USART_SAM_INIT_CFG(n) \
USART_SAM_DECLARE_CFG(n, USART_SAM_IRQ_CFG_FUNC_INIT(n))
#else
#define USART_SAM_CONFIG_FUNC(n)
#define USART_SAM_IRQ_CFG_FUNC_INIT
#define USART_SAM_INIT_CFG(n) \
USART_SAM_DECLARE_CFG(n, USART_SAM_IRQ_CFG_FUNC_INIT)
#endif
#define USART_SAM_INIT(n) \
static struct usart_sam_dev_data usart##n##_sam_data = { \
.baud_rate = DT_INST_PROP(n, current_speed), \
}; \
\
static const struct usart_sam_dev_cfg usart##n##_sam_config; \
\
DEVICE_AND_API_INIT(usart##n##_sam, DT_INST_LABEL(n), \
&usart_sam_init, &usart##n##_sam_data, \
&usart##n##_sam_config, PRE_KERNEL_1, \
CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
&usart_sam_driver_api); \
\
USART_SAM_CONFIG_FUNC(n) \
\
USART_SAM_INIT_CFG(n);
DT_INST_FOREACH_STATUS_OKAY(USART_SAM_INIT)