zephyr/drivers/serial/uart_nrf5.c

470 lines
12 KiB
C

/*
* Copyright (c) 2016 Nordic Semiconductor ASA
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @brief Driver for Nordic Semiconductor nRF5X UART
*/
#include <nanokernel.h>
#include <arch/cpu.h>
#include <misc/__assert.h>
#include <board.h>
#include <init.h>
#include <uart.h>
#include <sections.h>
#include <gpio.h>
/* UART structure for nRF5X. More detailed description of each register can be found in nrf5X.h */
struct _uart {
__O uint32_t TASKS_STARTRX;
__O uint32_t TASKS_STOPRX;
__O uint32_t TASKS_STARTTX;
__O uint32_t TASKS_STOPTX;
__I uint32_t RESERVED0[3];
__O uint32_t TASKS_SUSPEND;
__I uint32_t RESERVED1[56];
__IO uint32_t EVENTS_CTS;
__IO uint32_t EVENTS_NCTS;
__IO uint32_t EVENTS_RXDRDY;
__I uint32_t RESERVED2[4];
__IO uint32_t EVENTS_TXDRDY;
__I uint32_t RESERVED3;
__IO uint32_t EVENTS_ERROR;
__I uint32_t RESERVED4[7];
__IO uint32_t EVENTS_RXTO;
__I uint32_t RESERVED5[46];
__IO uint32_t SHORTS;
__I uint32_t RESERVED6[64];
__IO uint32_t INTENSET;
__IO uint32_t INTENCLR;
__I uint32_t RESERVED7[93];
__IO uint32_t ERRORSRC;
__I uint32_t RESERVED8[31];
__IO uint32_t ENABLE;
__I uint32_t RESERVED9;
__IO uint32_t PSELRTS;
__IO uint32_t PSELTXD;
__IO uint32_t PSELCTS;
__IO uint32_t PSELRXD;
__I uint32_t RXD;
__O uint32_t TXD;
__I uint32_t RESERVED10;
__IO uint32_t BAUDRATE;
__I uint32_t RESERVED11[17];
__IO uint32_t CONFIG;
};
/* Device data structure */
struct uart_nrf5_dev_data_t {
uint32_t baud_rate; /**< Baud rate */
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
uart_irq_callback_t cb; /**< Callback function pointer */
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
};
/* convenience defines */
#define DEV_CFG(dev) \
((struct uart_device_config * const)(dev)->config->config_info)
#define DEV_DATA(dev) \
((struct uart_nrf5_dev_data_t * const)(dev)->driver_data)
#define UART_STRUCT(dev) \
((volatile struct _uart *)(DEV_CFG(dev))->base)
#define UART_IRQ_MASK_RX (1 << 2)
#define UART_IRQ_MASK_TX (1 << 3)
#define UART_IRQ_MASK_ERROR (1 << 4)
static struct uart_driver_api uart_nrf5_driver_api;
/**
* @brief Set the baud rate
*
* This routine set the given baud rate for the UART.
*
* @param dev UART device struct
* @param baudrate Baud rate
* @param sys_clk_freq_hz System clock frequency in Hz
*
* @return N/A
*/
static void baudrate_set(struct device *dev,
uint32_t baudrate, uint32_t sys_clk_freq_hz)
{
volatile struct _uart *uart = UART_STRUCT(dev);
uint32_t set_baudrate; /* baud rate divisor */
if ((baudrate != 0) && (sys_clk_freq_hz != 0)) {
set_baudrate = (uint32_t) (
(uint64_t)baudrate *
(uint64_t)UINT32_MAX /
(uint64_t)sys_clk_freq_hz
);
/* Round the value */
set_baudrate = (set_baudrate + 0x800) & 0xFFFFF000;
uart->BAUDRATE = set_baudrate << UART_BAUDRATE_BAUDRATE_Pos;
}
}
/**
* @brief Initialize UART channel
*
* This routine is called to reset the chip in a quiescent state.
* It is assumed that this function is called only once per UART.
*
* @param dev UART device struct
*
* @return 0 on success
*/
static int uart_nrf5_init(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
struct device *gpio_dev;
gpio_dev = device_get_binding(CONFIG_GPIO_NRF5_P0_DEV_NAME);
(void) gpio_pin_configure(gpio_dev,
CONFIG_UART_NRF5_GPIO_TX_PIN,
(GPIO_DIR_OUT | GPIO_PUD_PULL_UP));
(void) gpio_pin_configure(gpio_dev,
CONFIG_UART_NRF5_GPIO_RX_PIN,
(GPIO_DIR_IN));
uart->PSELTXD = CONFIG_UART_NRF5_GPIO_TX_PIN;
uart->PSELRXD = CONFIG_UART_NRF5_GPIO_RX_PIN;
#ifdef CONFIG_UART_NRF5_FLOW_CONTROL
(void) gpio_pin_configure(gpio_dev,
CONFIG_UART_NRF5_GPIO_RTS_PIN,
(GPIO_DIR_OUT | GPIO_PUD_PULL_UP));
(void) gpio_pin_configure(gpio_dev,
CONFIG_UART_NRF5_GPIO_CTS_PIN,
(GPIO_DIR_IN));
uart->PSELRTS = CONFIG_UART_NRF5_GPIO_RTS_PIN;
uart->PSELCTS = CONFIG_UART_NRF5_GPIO_CTS_PIN;
uart->CONFIG = (UART_CONFIG_HWFC_Enabled << UART_CONFIG_HWFC_Pos);
#endif /* CONFIG_UART_NRF5_FLOW_CONTROL */
DEV_DATA(dev)->baud_rate = CONFIG_UART_NRF5_BAUD_RATE;
DEV_CFG(dev)->sys_clk_freq = CONFIG_UART_NRF5_CLK_FREQ;
/* Set baud rate */
baudrate_set(dev, DEV_DATA(dev)->baud_rate,
DEV_CFG(dev)->sys_clk_freq);
/* Enable receiver and transmitter */
uart->ENABLE = (UART_ENABLE_ENABLE_Enabled << UART_ENABLE_ENABLE_Pos);
uart->EVENTS_TXDRDY = 0;
uart->EVENTS_RXDRDY = 0;
uart->TASKS_STARTTX = 1;
uart->TASKS_STARTRX = 1;
dev->driver_api = &uart_nrf5_driver_api;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
DEV_CFG(dev)->irq_config_func(dev);
#endif
return 0;
}
/**
* @brief Poll the device for input.
*
* @param dev UART device struct
* @param c Pointer to character
*
* @return 0 if a character arrived, -1 if the input buffer if empty.
*/
static int uart_nrf5_poll_in(struct device *dev, unsigned char *c)
{
volatile struct _uart *uart = UART_STRUCT(dev);
if (!uart->EVENTS_RXDRDY) {
return -1;
}
/* Clear the interrupt */
uart->EVENTS_RXDRDY = 0;
/* got a character */
*c = (unsigned char)uart->RXD;
return 0;
}
/**
* @brief Output a character in polled mode.
*
* Checks if the transmitter is empty. If empty, a character is written to
* the data register.
*
* @param dev UART device struct
* @param c Character to send
*
* @return Sent character
*/
static unsigned char uart_nrf5_poll_out(struct device *dev,
unsigned char c)
{
volatile struct _uart *uart = UART_STRUCT(dev);
/* send a character */
uart->TXD = (uint8_t)c;
/* Wait for transmitter to be ready */
while (!uart->EVENTS_TXDRDY) {
}
uart->EVENTS_TXDRDY = 0;
return c;
}
/** Console I/O function */
static int uart_nrf5_err_check(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
uint32_t error = 0;
if (uart->EVENTS_ERROR) {
/* register bitfields maps to the defines in uart.h */
error = uart->ERRORSRC;
/* Clear the register */
uart->ERRORSRC = error;
}
error = error & 0x0F;
return error;
}
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
/** Interrupt driven FIFO fill function */
static int uart_nrf5_fifo_fill(struct device *dev, const uint8_t *tx_data, int len)
{
volatile struct _uart *uart = UART_STRUCT(dev);
uint8_t num_tx = 0;
while ((len - num_tx > 0) && uart->EVENTS_TXDRDY) {
/* Clear the interrupt */
uart->EVENTS_TXDRDY = 0;
/* Send a character */
uart->TXD = (uint8_t)tx_data[num_tx++];
}
return (int)num_tx;
}
/** Interrupt driven FIFO read function */
static int uart_nrf5_fifo_read(struct device *dev, uint8_t *rx_data, const int size)
{
volatile struct _uart *uart = UART_STRUCT(dev);
uint8_t num_rx = 0;
while ((size - num_rx > 0) && uart->EVENTS_RXDRDY) {
/* Clear the interrupt */
uart->EVENTS_RXDRDY = 0;
/* Receive a character */
rx_data[num_rx++] = (uint8_t)uart->RXD;
}
return num_rx;
}
/** Interrupt driven transfer enabling function */
static void uart_nrf5_irq_tx_enable(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
uart->INTENSET |= UART_IRQ_MASK_TX;
}
/** Interrupt driven transfer disabling function */
static void uart_nrf5_irq_tx_disable(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
uart->INTENCLR |= UART_IRQ_MASK_TX;
}
/** Interrupt driven transfer ready function */
static int uart_nrf5_irq_tx_ready(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
return uart->EVENTS_TXDRDY;
}
/** Interrupt driven receiver enabling function */
static void uart_nrf5_irq_rx_enable(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
uart->INTENSET |= UART_IRQ_MASK_RX;
}
/** Interrupt driven receiver disabling function */
static void uart_nrf5_irq_rx_disable(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
uart->INTENCLR |= UART_IRQ_MASK_RX;
}
/** Interrupt driven transfer empty function */
static int uart_nrf5_irq_tx_empty(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
return !(uart->EVENTS_TXDRDY);
}
/** Interrupt driven receiver ready function */
static int uart_nrf5_irq_rx_ready(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
return uart->EVENTS_RXDRDY;
}
/** Interrupt driven error enabling function */
static void uart_nrf5_irq_err_enable(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
uart->INTENSET |= UART_IRQ_MASK_ERROR;
}
/** Interrupt driven error disabling function */
static void uart_nrf5_irq_err_disable(struct device *dev)
{
volatile struct _uart *uart = UART_STRUCT(dev);
uart->INTENCLR |= UART_IRQ_MASK_ERROR;
}
/** Interrupt driven pending status function */
static int uart_nrf5_irq_is_pending(struct device *dev)
{
return (uart_nrf5_irq_tx_ready(dev) || uart_nrf5_irq_rx_ready(dev));
}
/** Interrupt driven interrupt update function */
static int uart_nrf5_irq_update(struct device *dev)
{
return 1;
}
/** Set the callback function */
static void uart_nrf5_irq_callback_set(struct device *dev, uart_irq_callback_t cb)
{
struct uart_nrf5_dev_data_t * const dev_data = DEV_DATA(dev);
dev_data->cb = cb;
}
/**
* @brief Interrupt service routine.
*
* This simply calls the callback function, if one exists.
*
* @param arg Argument to ISR.
*
* @return N/A
*/
void uart_nrf5_isr(void *arg)
{
struct device *dev = arg;
struct uart_nrf5_dev_data_t * const dev_data = DEV_DATA(dev);
if (dev_data->cb) {
dev_data->cb(dev);
}
}
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
static struct uart_driver_api uart_nrf5_driver_api = {
.poll_in = uart_nrf5_poll_in, /** Console I/O function */
.poll_out = uart_nrf5_poll_out, /** Console I/O function */
.err_check = uart_nrf5_err_check, /** Console I/O function */
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.fifo_fill = uart_nrf5_fifo_fill, /** IRQ FIFO fill function */
.fifo_read = uart_nrf5_fifo_read, /** IRQ FIFO read function */
.irq_tx_enable = uart_nrf5_irq_tx_enable, /** IRQ transfer enabling function */
.irq_tx_disable = uart_nrf5_irq_tx_disable, /** IRQ transfer disabling function */
.irq_tx_ready = uart_nrf5_irq_tx_ready, /** IRQ transfer ready function */
.irq_rx_enable = uart_nrf5_irq_rx_enable, /** IRQ receiver enabling function */
.irq_rx_disable = uart_nrf5_irq_rx_disable, /** IRQ receiver disabling function */
.irq_tx_empty = uart_nrf5_irq_tx_empty, /** IRQ transfer empty function */
.irq_rx_ready = uart_nrf5_irq_rx_ready, /** IRQ receiver ready function */
.irq_err_enable = uart_nrf5_irq_err_enable, /** IRQ error enabling function */
.irq_err_disable = uart_nrf5_irq_err_disable, /** IRQ error disabling function */
.irq_is_pending = uart_nrf5_irq_is_pending, /** IRQ pending status function */
.irq_update = uart_nrf5_irq_update, /** IRQ interrupt update function */
.irq_callback_set = uart_nrf5_irq_callback_set, /** Set the callback function */
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
};
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
/* Forward declare function */
static void uart_nrf5_irq_config(struct device *port);
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
static struct uart_device_config uart_nrf5_dev_cfg_0 = {
.base = (uint8_t *)NRF_UART0_BASE,
.sys_clk_freq = CONFIG_UART_NRF5_CLK_FREQ,
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.irq_config_func = uart_nrf5_irq_config,
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
};
static struct uart_nrf5_dev_data_t uart_nrf5_dev_data_0 = {
.baud_rate = CONFIG_UART_NRF5_BAUD_RATE,
};
DEVICE_INIT(uart_nrf5_0, CONFIG_UART_NRF5_NAME, &uart_nrf5_init,
&uart_nrf5_dev_data_0, &uart_nrf5_dev_cfg_0,
PRIMARY, CONFIG_KERNEL_INIT_PRIORITY_DEVICE);
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static void uart_nrf5_irq_config(struct device *port)
{
IRQ_CONNECT(NRF52_IRQ_UARTE0_UART0_IRQn,
CONFIG_UART_NRF5_IRQ_PRI,
uart_nrf5_isr, DEVICE_GET(uart_nrf5_0),
0);
irq_enable(NRF52_IRQ_UARTE0_UART0_IRQn);
}
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */