/
uart_sam0.c
1316 lines (1070 loc) · 32 KB
/
uart_sam0.c
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/*
* Copyright (c) 2017 Google LLC.
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT atmel_sam0_uart
#include <zephyr/device.h>
#include <errno.h>
#include <zephyr/init.h>
#include <zephyr/sys/__assert.h>
#include <soc.h>
#include <zephyr/drivers/uart.h>
#include <zephyr/drivers/dma.h>
#include <zephyr/drivers/pinctrl.h>
#include <string.h>
#include <zephyr/irq.h>
#ifndef SERCOM_USART_CTRLA_MODE_USART_INT_CLK
#define SERCOM_USART_CTRLA_MODE_USART_INT_CLK SERCOM_USART_CTRLA_MODE(0x1)
#endif
/*
* Interrupt error flag is only supported in devices with
* SERCOM revision 0x500
*/
#if defined(SERCOM_U2201) && (REV_SERCOM == 0x500)
#define SERCOM_REV500
#endif
/* Device constant configuration parameters */
struct uart_sam0_dev_cfg {
SercomUsart *regs;
uint32_t baudrate;
uint32_t pads;
bool collision_detect;
#ifdef MCLK
volatile uint32_t *mclk;
uint32_t mclk_mask;
uint16_t gclk_core_id;
#else
uint32_t pm_apbcmask;
uint16_t gclk_clkctrl_id;
#endif
#if CONFIG_UART_INTERRUPT_DRIVEN || CONFIG_UART_SAM0_ASYNC
void (*irq_config_func)(const struct device *dev);
#endif
#if CONFIG_UART_SAM0_ASYNC
const struct device *dma_dev;
uint8_t tx_dma_request;
uint8_t tx_dma_channel;
uint8_t rx_dma_request;
uint8_t rx_dma_channel;
#endif
const struct pinctrl_dev_config *pcfg;
};
/* Device run time data */
struct uart_sam0_dev_data {
struct uart_config config_cache;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
uart_irq_callback_user_data_t cb;
void *cb_data;
uint8_t txc_cache;
#endif
#if CONFIG_UART_SAM0_ASYNC
const struct device *dev;
const struct uart_sam0_dev_cfg *cfg;
uart_callback_t async_cb;
void *async_cb_data;
struct k_work_delayable tx_timeout_work;
const uint8_t *tx_buf;
size_t tx_len;
struct k_work_delayable rx_timeout_work;
size_t rx_timeout_time;
size_t rx_timeout_chunk;
uint32_t rx_timeout_start;
uint8_t *rx_buf;
size_t rx_len;
size_t rx_processed_len;
uint8_t *rx_next_buf;
size_t rx_next_len;
bool rx_waiting_for_irq;
bool rx_timeout_from_isr;
#endif
};
static void wait_synchronization(SercomUsart *const usart)
{
#if defined(SERCOM_USART_SYNCBUSY_MASK)
/* SYNCBUSY is a register */
while ((usart->SYNCBUSY.reg & SERCOM_USART_SYNCBUSY_MASK) != 0) {
}
#elif defined(SERCOM_USART_STATUS_SYNCBUSY)
/* SYNCBUSY is a bit */
while ((usart->STATUS.reg & SERCOM_USART_STATUS_SYNCBUSY) != 0) {
}
#else
#error Unsupported device
#endif
}
static int uart_sam0_set_baudrate(SercomUsart *const usart, uint32_t baudrate,
uint32_t clk_freq_hz)
{
uint64_t tmp;
uint16_t baud;
tmp = (uint64_t)baudrate << 20;
tmp = (tmp + (clk_freq_hz >> 1)) / clk_freq_hz;
/* Verify that the calculated result is within range */
if (tmp < 1 || tmp > UINT16_MAX) {
return -ERANGE;
}
baud = 65536 - (uint16_t)tmp;
usart->BAUD.reg = baud;
wait_synchronization(usart);
return 0;
}
#if CONFIG_UART_SAM0_ASYNC
static void uart_sam0_dma_tx_done(const struct device *dma_dev, void *arg,
uint32_t id, int error_code)
{
ARG_UNUSED(dma_dev);
ARG_UNUSED(id);
ARG_UNUSED(error_code);
struct uart_sam0_dev_data *const dev_data =
(struct uart_sam0_dev_data *const) arg;
const struct uart_sam0_dev_cfg *const cfg = dev_data->cfg;
SercomUsart * const regs = cfg->regs;
regs->INTENSET.reg = SERCOM_USART_INTENSET_TXC;
}
static int uart_sam0_tx_halt(struct uart_sam0_dev_data *dev_data)
{
const struct uart_sam0_dev_cfg *const cfg = dev_data->cfg;
unsigned int key = irq_lock();
size_t tx_active = dev_data->tx_len;
struct dma_status st;
struct uart_event evt = {
.type = UART_TX_ABORTED,
.data.tx = {
.buf = dev_data->tx_buf,
.len = 0U,
},
};
dev_data->tx_buf = NULL;
dev_data->tx_len = 0U;
dma_stop(cfg->dma_dev, cfg->tx_dma_channel);
irq_unlock(key);
if (dma_get_status(cfg->dma_dev, cfg->tx_dma_channel, &st) == 0) {
evt.data.tx.len = tx_active - st.pending_length;
}
if (tx_active) {
if (dev_data->async_cb) {
dev_data->async_cb(dev_data->dev,
&evt, dev_data->async_cb_data);
}
} else {
return -EINVAL;
}
return 0;
}
static void uart_sam0_tx_timeout(struct k_work *work)
{
struct k_work_delayable *dwork = k_work_delayable_from_work(work);
struct uart_sam0_dev_data *dev_data = CONTAINER_OF(dwork,
struct uart_sam0_dev_data, tx_timeout_work);
uart_sam0_tx_halt(dev_data);
}
static void uart_sam0_notify_rx_processed(struct uart_sam0_dev_data *dev_data,
size_t processed)
{
if (!dev_data->async_cb) {
return;
}
if (dev_data->rx_processed_len == processed) {
return;
}
struct uart_event evt = {
.type = UART_RX_RDY,
.data.rx = {
.buf = dev_data->rx_buf,
.offset = dev_data->rx_processed_len,
.len = processed - dev_data->rx_processed_len,
},
};
dev_data->rx_processed_len = processed;
dev_data->async_cb(dev_data->dev,
&evt, dev_data->async_cb_data);
}
static void uart_sam0_dma_rx_done(const struct device *dma_dev, void *arg,
uint32_t id, int error_code)
{
ARG_UNUSED(dma_dev);
ARG_UNUSED(id);
ARG_UNUSED(error_code);
struct uart_sam0_dev_data *const dev_data =
(struct uart_sam0_dev_data *const)arg;
const struct device *dev = dev_data->dev;
const struct uart_sam0_dev_cfg *const cfg = dev_data->cfg;
SercomUsart * const regs = cfg->regs;
unsigned int key = irq_lock();
if (dev_data->rx_len == 0U) {
irq_unlock(key);
return;
}
uart_sam0_notify_rx_processed(dev_data, dev_data->rx_len);
if (dev_data->async_cb) {
struct uart_event evt = {
.type = UART_RX_BUF_RELEASED,
.data.rx_buf = {
.buf = dev_data->rx_buf,
},
};
dev_data->async_cb(dev, &evt, dev_data->async_cb_data);
}
/* No next buffer, so end the transfer */
if (!dev_data->rx_next_len) {
dev_data->rx_buf = NULL;
dev_data->rx_len = 0U;
if (dev_data->async_cb) {
struct uart_event evt = {
.type = UART_RX_DISABLED,
};
dev_data->async_cb(dev, &evt, dev_data->async_cb_data);
}
irq_unlock(key);
return;
}
dev_data->rx_buf = dev_data->rx_next_buf;
dev_data->rx_len = dev_data->rx_next_len;
dev_data->rx_next_buf = NULL;
dev_data->rx_next_len = 0U;
dev_data->rx_processed_len = 0U;
dma_reload(cfg->dma_dev, cfg->rx_dma_channel,
(uint32_t)(&(regs->DATA.reg)),
(uint32_t)dev_data->rx_buf, dev_data->rx_len);
/*
* If there should be a timeout, handle starting the DMA in the
* ISR, since reception resets it and DMA completion implies
* reception. This also catches the case of DMA completion during
* timeout handling.
*/
if (dev_data->rx_timeout_time != SYS_FOREVER_US) {
dev_data->rx_waiting_for_irq = true;
regs->INTENSET.reg = SERCOM_USART_INTENSET_RXC;
irq_unlock(key);
return;
}
/* Otherwise, start the transfer immediately. */
dma_start(cfg->dma_dev, cfg->rx_dma_channel);
struct uart_event evt = {
.type = UART_RX_BUF_REQUEST,
};
dev_data->async_cb(dev, &evt, dev_data->async_cb_data);
irq_unlock(key);
}
static void uart_sam0_rx_timeout(struct k_work *work)
{
struct k_work_delayable *dwork = k_work_delayable_from_work(work);
struct uart_sam0_dev_data *dev_data = CONTAINER_OF(dwork,
struct uart_sam0_dev_data, rx_timeout_work);
const struct uart_sam0_dev_cfg *const cfg = dev_data->cfg;
SercomUsart * const regs = cfg->regs;
struct dma_status st;
unsigned int key = irq_lock();
if (dev_data->rx_len == 0U) {
irq_unlock(key);
return;
}
/*
* Stop the DMA transfer and restart the interrupt read
* component (so the timeout restarts if there's still data).
* However, just ignore it if the transfer has completed (nothing
* pending) that means the DMA ISR is already pending, so just let
* it handle things instead when we re-enable IRQs.
*/
dma_stop(cfg->dma_dev, cfg->rx_dma_channel);
if (dma_get_status(cfg->dma_dev, cfg->rx_dma_channel,
&st) == 0 && st.pending_length == 0U) {
irq_unlock(key);
return;
}
uint8_t *rx_dma_start = dev_data->rx_buf + dev_data->rx_len -
st.pending_length;
size_t rx_processed = rx_dma_start - dev_data->rx_buf;
/*
* We know we still have space, since the above will catch the
* empty buffer, so always restart the transfer.
*/
dma_reload(cfg->dma_dev, cfg->rx_dma_channel,
(uint32_t)(&(regs->DATA.reg)),
(uint32_t)rx_dma_start,
dev_data->rx_len - rx_processed);
dev_data->rx_waiting_for_irq = true;
regs->INTENSET.reg = SERCOM_USART_INTENSET_RXC;
/*
* Never do a notify on a timeout started from the ISR: timing
* granularity means the first timeout can be in the middle
* of reception but still have the total elapsed time exhausted.
* So we require a timeout chunk with no data seen at all
* (i.e. no ISR entry).
*/
if (dev_data->rx_timeout_from_isr) {
dev_data->rx_timeout_from_isr = false;
k_work_reschedule(&dev_data->rx_timeout_work,
K_USEC(dev_data->rx_timeout_chunk));
irq_unlock(key);
return;
}
uint32_t now = k_uptime_get_32();
uint32_t elapsed = now - dev_data->rx_timeout_start;
if (elapsed >= dev_data->rx_timeout_time) {
/*
* No time left, so call the handler, and let the ISR
* restart the timeout when it sees data.
*/
uart_sam0_notify_rx_processed(dev_data, rx_processed);
} else {
/*
* Still have time left, so start another timeout.
*/
uint32_t remaining = MIN(dev_data->rx_timeout_time - elapsed,
dev_data->rx_timeout_chunk);
k_work_reschedule(&dev_data->rx_timeout_work,
K_USEC(remaining));
}
irq_unlock(key);
}
#endif
#ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE
static int uart_sam0_configure(const struct device *dev,
const struct uart_config *new_cfg)
{
int retval;
const struct uart_sam0_dev_cfg *const cfg = dev->config;
struct uart_sam0_dev_data *const dev_data = dev->data;
SercomUsart * const usart = cfg->regs;
wait_synchronization(usart);
usart->CTRLA.bit.ENABLE = 0;
wait_synchronization(usart);
if (new_cfg->flow_ctrl != UART_CFG_FLOW_CTRL_NONE) {
/* Flow control not yet supported though in principle possible
* on this soc family.
*/
return -ENOTSUP;
}
dev_data->config_cache.flow_ctrl = new_cfg->flow_ctrl;
SERCOM_USART_CTRLA_Type CTRLA_temp = usart->CTRLA;
SERCOM_USART_CTRLB_Type CTRLB_temp = usart->CTRLB;
switch (new_cfg->parity) {
case UART_CFG_PARITY_NONE:
CTRLA_temp.bit.FORM = 0x0;
break;
case UART_CFG_PARITY_ODD:
CTRLA_temp.bit.FORM = 0x1;
CTRLB_temp.bit.PMODE = 1;
break;
case UART_CFG_PARITY_EVEN:
CTRLA_temp.bit.FORM = 0x1;
CTRLB_temp.bit.PMODE = 0;
break;
default:
return -ENOTSUP;
}
dev_data->config_cache.parity = new_cfg->parity;
switch (new_cfg->stop_bits) {
case UART_CFG_STOP_BITS_1:
CTRLB_temp.bit.SBMODE = 0;
break;
case UART_CFG_STOP_BITS_2:
CTRLB_temp.bit.SBMODE = 1;
break;
default:
return -ENOTSUP;
}
dev_data->config_cache.stop_bits = new_cfg->stop_bits;
switch (new_cfg->data_bits) {
case UART_CFG_DATA_BITS_5:
CTRLB_temp.bit.CHSIZE = 0x5;
break;
case UART_CFG_DATA_BITS_6:
CTRLB_temp.bit.CHSIZE = 0x6;
break;
case UART_CFG_DATA_BITS_7:
CTRLB_temp.bit.CHSIZE = 0x7;
break;
case UART_CFG_DATA_BITS_8:
CTRLB_temp.bit.CHSIZE = 0x0;
break;
case UART_CFG_DATA_BITS_9:
CTRLB_temp.bit.CHSIZE = 0x1;
break;
default:
return -ENOTSUP;
}
dev_data->config_cache.data_bits = new_cfg->data_bits;
#if defined(SERCOM_REV500)
CTRLB_temp.bit.COLDEN = cfg->pads;
#endif
usart->CTRLA = CTRLA_temp;
wait_synchronization(usart);
usart->CTRLB = CTRLB_temp;
wait_synchronization(usart);
retval = uart_sam0_set_baudrate(usart, new_cfg->baudrate,
SOC_ATMEL_SAM0_GCLK0_FREQ_HZ);
if (retval != 0) {
return retval;
}
dev_data->config_cache.baudrate = new_cfg->baudrate;
usart->CTRLA.bit.ENABLE = 1;
wait_synchronization(usart);
return 0;
}
static int uart_sam0_config_get(const struct device *dev,
struct uart_config *out_cfg)
{
struct uart_sam0_dev_data *const dev_data = dev->data;
memcpy(out_cfg, &(dev_data->config_cache),
sizeof(dev_data->config_cache));
return 0;
}
#endif /* CONFIG_UART_USE_RUNTIME_CONFIGURE */
static int uart_sam0_init(const struct device *dev)
{
int retval;
const struct uart_sam0_dev_cfg *const cfg = dev->config;
struct uart_sam0_dev_data *const dev_data = dev->data;
SercomUsart * const usart = cfg->regs;
#ifdef MCLK
/* Enable the GCLK */
GCLK->PCHCTRL[cfg->gclk_core_id].reg = GCLK_PCHCTRL_GEN_GCLK0 |
GCLK_PCHCTRL_CHEN;
/* Enable SERCOM clock in MCLK */
*cfg->mclk |= cfg->mclk_mask;
#else
/* Enable the GCLK */
GCLK->CLKCTRL.reg = cfg->gclk_clkctrl_id | GCLK_CLKCTRL_GEN_GCLK0 |
GCLK_CLKCTRL_CLKEN;
/* Enable SERCOM clock in PM */
PM->APBCMASK.reg |= cfg->pm_apbcmask;
#endif
/* Disable all USART interrupts */
usart->INTENCLR.reg = SERCOM_USART_INTENCLR_MASK;
wait_synchronization(usart);
/* 8 bits of data, no parity, 1 stop bit in normal mode */
usart->CTRLA.reg =
cfg->pads
/* Internal clock */
| SERCOM_USART_CTRLA_MODE_USART_INT_CLK
#if defined(SERCOM_USART_CTRLA_SAMPR)
/* 16x oversampling with arithmetic baud rate generation */
| SERCOM_USART_CTRLA_SAMPR(0)
#endif
| SERCOM_USART_CTRLA_FORM(0) |
SERCOM_USART_CTRLA_CPOL | SERCOM_USART_CTRLA_DORD;
wait_synchronization(usart);
/* Enable PINMUX based on PINCTRL */
retval = pinctrl_apply_state(cfg->pcfg, PINCTRL_STATE_DEFAULT);
if (retval < 0) {
return retval;
}
dev_data->config_cache.flow_ctrl = UART_CFG_FLOW_CTRL_NONE;
dev_data->config_cache.parity = UART_CFG_PARITY_NONE;
dev_data->config_cache.stop_bits = UART_CFG_STOP_BITS_1;
dev_data->config_cache.data_bits = UART_CFG_DATA_BITS_8;
/* Enable receiver and transmitter */
usart->CTRLB.reg = SERCOM_USART_CTRLB_CHSIZE(0) |
SERCOM_USART_CTRLB_RXEN | SERCOM_USART_CTRLB_TXEN;
wait_synchronization(usart);
retval = uart_sam0_set_baudrate(usart, cfg->baudrate,
SOC_ATMEL_SAM0_GCLK0_FREQ_HZ);
if (retval != 0) {
return retval;
}
dev_data->config_cache.baudrate = cfg->baudrate;
#if CONFIG_UART_INTERRUPT_DRIVEN || CONFIG_UART_SAM0_ASYNC
cfg->irq_config_func(dev);
#endif
#ifdef CONFIG_UART_SAM0_ASYNC
dev_data->dev = dev;
dev_data->cfg = cfg;
if (!device_is_ready(cfg->dma_dev)) {
return -ENODEV;
}
k_work_init_delayable(&dev_data->tx_timeout_work, uart_sam0_tx_timeout);
k_work_init_delayable(&dev_data->rx_timeout_work, uart_sam0_rx_timeout);
if (cfg->tx_dma_channel != 0xFFU) {
struct dma_config dma_cfg = { 0 };
struct dma_block_config dma_blk = { 0 };
dma_cfg.channel_direction = MEMORY_TO_PERIPHERAL;
dma_cfg.source_data_size = 1;
dma_cfg.dest_data_size = 1;
dma_cfg.user_data = dev_data;
dma_cfg.dma_callback = uart_sam0_dma_tx_done;
dma_cfg.block_count = 1;
dma_cfg.head_block = &dma_blk;
dma_cfg.dma_slot = cfg->tx_dma_request;
dma_blk.block_size = 1;
dma_blk.dest_address = (uint32_t)(&(usart->DATA.reg));
dma_blk.dest_addr_adj = DMA_ADDR_ADJ_NO_CHANGE;
retval = dma_config(cfg->dma_dev, cfg->tx_dma_channel,
&dma_cfg);
if (retval != 0) {
return retval;
}
}
if (cfg->rx_dma_channel != 0xFFU) {
struct dma_config dma_cfg = { 0 };
struct dma_block_config dma_blk = { 0 };
dma_cfg.channel_direction = PERIPHERAL_TO_MEMORY;
dma_cfg.source_data_size = 1;
dma_cfg.dest_data_size = 1;
dma_cfg.user_data = dev_data;
dma_cfg.dma_callback = uart_sam0_dma_rx_done;
dma_cfg.block_count = 1;
dma_cfg.head_block = &dma_blk;
dma_cfg.dma_slot = cfg->rx_dma_request;
dma_blk.block_size = 1;
dma_blk.source_address = (uint32_t)(&(usart->DATA.reg));
dma_blk.source_addr_adj = DMA_ADDR_ADJ_NO_CHANGE;
retval = dma_config(cfg->dma_dev, cfg->rx_dma_channel,
&dma_cfg);
if (retval != 0) {
return retval;
}
}
#endif
usart->CTRLA.bit.ENABLE = 1;
wait_synchronization(usart);
return 0;
}
static int uart_sam0_poll_in(const struct device *dev, unsigned char *c)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const usart = config->regs;
if (!usart->INTFLAG.bit.RXC) {
return -EBUSY;
}
*c = (unsigned char)usart->DATA.reg;
return 0;
}
static void uart_sam0_poll_out(const struct device *dev, unsigned char c)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const usart = config->regs;
while (!usart->INTFLAG.bit.DRE) {
}
/* send a character */
usart->DATA.reg = c;
}
static int uart_sam0_err_check(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
uint32_t err = 0U;
if (regs->STATUS.reg & SERCOM_USART_STATUS_BUFOVF) {
err |= UART_ERROR_OVERRUN;
}
if (regs->STATUS.reg & SERCOM_USART_STATUS_FERR) {
err |= UART_ERROR_PARITY;
}
if (regs->STATUS.reg & SERCOM_USART_STATUS_PERR) {
err |= UART_ERROR_FRAMING;
}
#if defined(SERCOM_REV500)
if (regs->STATUS.reg & SERCOM_USART_STATUS_ISF) {
err |= UART_BREAK;
}
if (regs->STATUS.reg & SERCOM_USART_STATUS_COLL) {
err |= UART_ERROR_COLLISION;
}
regs->STATUS.reg |= SERCOM_USART_STATUS_BUFOVF
| SERCOM_USART_STATUS_FERR
| SERCOM_USART_STATUS_PERR
| SERCOM_USART_STATUS_COLL
| SERCOM_USART_STATUS_ISF;
#else
regs->STATUS.reg |= SERCOM_USART_STATUS_BUFOVF
| SERCOM_USART_STATUS_FERR
| SERCOM_USART_STATUS_PERR;
#endif
wait_synchronization(regs);
return err;
}
#if CONFIG_UART_INTERRUPT_DRIVEN || CONFIG_UART_SAM0_ASYNC
static void uart_sam0_isr(const struct device *dev)
{
struct uart_sam0_dev_data *const dev_data = dev->data;
#if CONFIG_UART_INTERRUPT_DRIVEN
if (dev_data->cb) {
dev_data->cb(dev, dev_data->cb_data);
}
#endif
#if CONFIG_UART_SAM0_ASYNC
const struct uart_sam0_dev_cfg *const cfg = dev->config;
SercomUsart * const regs = cfg->regs;
if (dev_data->tx_len && regs->INTFLAG.bit.TXC) {
regs->INTENCLR.reg = SERCOM_USART_INTENCLR_TXC;
k_work_cancel_delayable(&dev_data->tx_timeout_work);
unsigned int key = irq_lock();
struct uart_event evt = {
.type = UART_TX_DONE,
.data.tx = {
.buf = dev_data->tx_buf,
.len = dev_data->tx_len,
},
};
dev_data->tx_buf = NULL;
dev_data->tx_len = 0U;
if (evt.data.tx.len != 0U && dev_data->async_cb) {
dev_data->async_cb(dev, &evt, dev_data->async_cb_data);
}
irq_unlock(key);
}
if (dev_data->rx_len && regs->INTFLAG.bit.RXC &&
dev_data->rx_waiting_for_irq) {
dev_data->rx_waiting_for_irq = false;
regs->INTENCLR.reg = SERCOM_USART_INTENCLR_RXC;
/* Receive started, so request the next buffer */
if (dev_data->rx_next_len == 0U && dev_data->async_cb) {
struct uart_event evt = {
.type = UART_RX_BUF_REQUEST,
};
dev_data->async_cb(dev, &evt, dev_data->async_cb_data);
}
/*
* If we have a timeout, restart the time remaining whenever
* we see data.
*/
if (dev_data->rx_timeout_time != SYS_FOREVER_US) {
dev_data->rx_timeout_from_isr = true;
dev_data->rx_timeout_start = k_uptime_get_32();
k_work_reschedule(&dev_data->rx_timeout_work,
K_USEC(dev_data->rx_timeout_chunk));
}
/* DMA will read the currently ready byte out */
dma_start(cfg->dma_dev, cfg->rx_dma_channel);
}
#endif
}
#endif
#if CONFIG_UART_INTERRUPT_DRIVEN
static int uart_sam0_fifo_fill(const struct device *dev,
const uint8_t *tx_data, int len)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart *regs = config->regs;
if (regs->INTFLAG.bit.DRE && len >= 1) {
regs->DATA.reg = tx_data[0];
return 1;
} else {
return 0;
}
}
static void uart_sam0_irq_tx_enable(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
regs->INTENSET.reg = SERCOM_USART_INTENSET_DRE
| SERCOM_USART_INTENSET_TXC;
}
static void uart_sam0_irq_tx_disable(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
regs->INTENCLR.reg = SERCOM_USART_INTENCLR_DRE
| SERCOM_USART_INTENCLR_TXC;
}
static int uart_sam0_irq_tx_ready(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
return (regs->INTFLAG.bit.DRE != 0) && (regs->INTENSET.bit.DRE != 0);
}
static int uart_sam0_irq_tx_complete(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
struct uart_sam0_dev_data *const dev_data = dev->data;
SercomUsart * const regs = config->regs;
return (dev_data->txc_cache != 0) && (regs->INTENSET.bit.TXC != 0);
}
static void uart_sam0_irq_rx_enable(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
regs->INTENSET.reg = SERCOM_USART_INTENSET_RXC;
}
static void uart_sam0_irq_rx_disable(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
regs->INTENCLR.reg = SERCOM_USART_INTENCLR_RXC;
}
static int uart_sam0_irq_rx_ready(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
return regs->INTFLAG.bit.RXC != 0;
}
static int uart_sam0_fifo_read(const struct device *dev, uint8_t *rx_data,
const int size)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
if (regs->INTFLAG.bit.RXC) {
uint8_t ch = regs->DATA.reg;
if (size >= 1) {
*rx_data = ch;
return 1;
} else {
return -EINVAL;
}
}
return 0;
}
static int uart_sam0_irq_is_pending(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
return (regs->INTENSET.reg & regs->INTFLAG.reg) != 0;
}
#if defined(SERCOM_REV500)
static void uart_sam0_irq_err_enable(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
regs->INTENSET.reg |= SERCOM_USART_INTENCLR_ERROR;
wait_synchronization(regs);
}
static void uart_sam0_irq_err_disable(const struct device *dev)
{
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
regs->INTENCLR.reg |= SERCOM_USART_INTENSET_ERROR;
wait_synchronization(regs);
}
#endif
static int uart_sam0_irq_update(const struct device *dev)
{
/* Clear sticky interrupts */
const struct uart_sam0_dev_cfg *config = dev->config;
SercomUsart * const regs = config->regs;
#if defined(SERCOM_REV500)
/*
* Cache the TXC flag, and use this cached value to clear the interrupt
* if we do not used the cached value, there is a chance TXC will set
* after caching...this will cause TXC to never cached.
*/
struct uart_sam0_dev_data *const dev_data = dev->data;
dev_data->txc_cache = regs->INTFLAG.bit.TXC;
regs->INTFLAG.reg = SERCOM_USART_INTENCLR_ERROR
| SERCOM_USART_INTENCLR_RXBRK
| SERCOM_USART_INTENCLR_CTSIC
| SERCOM_USART_INTENCLR_RXS
| (dev_data->txc_cache << SERCOM_USART_INTENCLR_TXC_Pos);
#else
regs->INTFLAG.reg = SERCOM_USART_INTENCLR_RXS;
#endif
return 1;
}
static void uart_sam0_irq_callback_set(const struct device *dev,
uart_irq_callback_user_data_t cb,
void *cb_data)
{
struct uart_sam0_dev_data *const dev_data = dev->data;
dev_data->cb = cb;
dev_data->cb_data = cb_data;
#if defined(CONFIG_UART_SAM0_ASYNC) && defined(CONFIG_UART_EXCLUSIVE_API_CALLBACKS)
dev_data->async_cb = NULL;
dev_data->async_cb_data = NULL;
#endif
}
#endif
#ifdef CONFIG_UART_SAM0_ASYNC
static int uart_sam0_callback_set(const struct device *dev,
uart_callback_t callback,
void *user_data)
{
struct uart_sam0_dev_data *const dev_data = dev->data;
dev_data->async_cb = callback;
dev_data->async_cb_data = user_data;
#if defined(CONFIG_UART_EXCLUSIVE_API_CALLBACKS)
dev_data->cb = NULL;
dev_data->cb_data = NULL;
#endif
return 0;
}
static int uart_sam0_tx(const struct device *dev, const uint8_t *buf,
size_t len,
int32_t timeout)
{
struct uart_sam0_dev_data *const dev_data = dev->data;
const struct uart_sam0_dev_cfg *const cfg = dev->config;
SercomUsart *regs = cfg->regs;
int retval;
if (cfg->tx_dma_channel == 0xFFU) {
return -ENOTSUP;
}
if (len > 0xFFFFU) {
return -EINVAL;
}
unsigned int key = irq_lock();
if (dev_data->tx_len != 0U) {
retval = -EBUSY;
goto err;
}
dev_data->tx_buf = buf;
dev_data->tx_len = len;
irq_unlock(key);
retval = dma_reload(cfg->dma_dev, cfg->tx_dma_channel, (uint32_t)buf,
(uint32_t)(&(regs->DATA.reg)), len);
if (retval != 0U) {
return retval;
}