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serial: added support for the SiFive Freedom E310 UART driver

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Change-Id: I7552b316bd328c67eabb1dbf62342cb9b663845a
Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
This commit is contained in:
Jean-Paul Etienne 2017-03-14 22:16:37 +01:00 • committed by Anas Nashif
commit a916cf7e19
4 changed files with 565 additions and 0 deletions
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2
drivers/serial/Kconfig
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@ -83,4 +83,6 @@ source "drivers/serial/Kconfig.cmsdk_apb"
source "drivers/serial/Kconfig.riscv_qemu"
source "drivers/serial/Kconfig.fe310"
endif

110
drivers/serial/Kconfig.fe310 Normal file
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@ -0,0 +1,110 @@
# Kconfig.fe310 - SiFive Freedom E310 UART configuration option
#
# Copyright (c) 2017 Jean-Paul Etienne <fractalclone@gmail.com>
#
# SPDX-License-Identifier: Apache-2.0
#
menuconfig UART_FE310
bool "SiFive Freedom E310 serial driver"
depends on SOC_RISCV32_FE310
default n
select SERIAL_HAS_DRIVER
help
This option enables the SiFive Freedom E310 serial driver.
# ---------- Port 0 ----------
menuconfig UART_FE310_PORT_0
bool "Enable FE310 Port 0"
default n
depends on UART_FE310
help
This tells the driver to configure the UART port at boot, depending on
the additional configure options below.
config UART_FE310_PORT_0_NAME
string "Port 0 Device Name"
default "uart0"
depends on UART_FE310_PORT_0
help
This is the device name for UART, and is included in the device
struct.
config UART_FE310_PORT_0_BAUD_RATE
int "Port 0 Baud Rate"
default 0
depends on UART_FE310_PORT_0
help
The baud rate for UART port to be set to at boot.
Leave at 0 to skip initialization.
config UART_FE310_PORT_0_IRQ_PRIORITY
int "Port 0 Interrupt Priority"
default 1
depends on UART_FE310_PORT_0
help
Port 0 Interrupt Priority
config UART_FE310_PORT_0_RXCNT_IRQ
int "Port 0 RX Interrupt Threshold Count"
default 0
depends on UART_FE310_PORT_0
help
Port 0 RX Threshold at which the RX FIFO interrupt triggers.
config UART_FE310_PORT_0_TXCNT_IRQ
int "Port 0 TX Interrupt Threshold Count"
default 0
depends on UART_FE310_PORT_0
help
Port 0 TX Threshold at which the TX FIFO interrupt triggers.
# ---------- Port 1 ----------
menuconfig UART_FE310_PORT_1
bool "Enable FE310 Port 1"
default n
depends on UART_FE310
help
This tells the driver to configure the UART port at boot, depending on
the additional configure options below.
config UART_FE310_PORT_1_NAME
string "Port 1 Device Name"
default "uart1"
depends on UART_FE310_PORT_1
help
This is the device name for UART, and is included in the device
struct.
config UART_FE310_PORT_1_BAUD_RATE
int "Port 1 Baud Rate"
default 0
depends on UART_FE310_PORT_1
help
The baud rate for UART port to be set to at boot.
Leave at 0 to skip initialization.
config UART_FE310_PORT_1_IRQ_PRIORITY
int "Port 1 Interrupt Priority"
default 1
depends on UART_FE310_PORT_1
help
Port 1 Interrupt Priority
config UART_FE310_PORT_1_RXCNT_IRQ
int "Port 0 RX Interrupt Threshold Count"
default 0
depends on UART_FE310_PORT_1
help
Port 1 RX Threshold at which the RX FIFO interrupt triggers.
config UART_FE310_PORT_1_TXCNT_IRQ
int "Port 1 TX Interrupt Threshold Count"
default 0
depends on UART_FE310_PORT_1
help
Port 1 TX Threshold at which the TX FIFO interrupt triggers.

1
drivers/serial/Makefile
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@ -15,3 +15,4 @@ obj-$(CONFIG_UART_ALTERA_JTAG) += uart_altera_jtag.o
obj-$(CONFIG_UART_CC32XX) += uart_cc32xx.o
obj-$(CONFIG_UART_CMSDK_APB) += uart_cmsdk_apb.o
obj-$(CONFIG_UART_RISCV_QEMU) += uart_riscv_qemu.o
obj-$(CONFIG_UART_FE310) += uart_fe310.o

452
drivers/serial/uart_fe310.c Normal file
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@ -0,0 +1,452 @@
/*
* Copyright (c) 2017 Jean-Paul Etienne <fractalclone@gmail.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @brief UART driver for the SiFive Freedom E310 Processor
*/
#include <kernel.h>
#include <arch/cpu.h>
#include <uart.h>
#include <board.h>
#define RXDATA_EMPTY (1 << 31) /* Receive FIFO Empty */
#define RXDATA_MASK 0xFF /* Receive Data Mask */
#define TXDATA_FULL (1 << 31) /* Transmit FIFO Full */
#define TXCTRL_TXEN (1 << 0) /* Activate Tx Channel */
#define RXCTRL_RXEN (1 << 0) /* Activate Rx Channel */
#define IE_TXWM (1 << 0) /* TX Interrupt Enable/Pending */
#define IE_RXWM (1 << 1) /* RX Interrupt Enable/Pending */
/*
* RX/TX Threshold count to generate TX/RX Interrupts.
* Used by txctrl and rxctrl registers
*/
#define CTRL_CNT(x) (((x) & 0x07) << 16)
struct uart_fe310_regs_t {
uint32_t tx;
uint32_t rx;
uint32_t txctrl;
uint32_t rxctrl;
uint32_t ie;
uint32_t ip;
uint32_t div;
};
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
typedef void (*irq_cfg_func_t)(void);
#endif
struct uart_fe310_device_config {
uint32_t port;
uint32_t sys_clk_freq;
uint32_t baud_rate;
uint32_t rxcnt_irq;
uint32_t txcnt_irq;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
irq_cfg_func_t cfg_func;
#endif
};
struct uart_fe310_data {
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
uart_irq_callback_t callback;
#endif
};
#define DEV_CFG(dev) \
((const struct uart_fe310_device_config * const) \
(dev)->config->config_info)
#define DEV_UART(dev) \
((struct uart_fe310_regs_t *)(DEV_CFG(dev))->port)
#define DEV_DATA(dev) \
((struct uart_fe310_data * const)(dev)->driver_data)
/**
* @brief Output a character in polled mode.
*
* Writes data to tx register if transmitter is not full.
*
* @param dev UART device struct
* @param c Character to send
*
* @return Sent character
*/
static unsigned char uart_fe310_poll_out(struct device *dev,
unsigned char c)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
/* Wait while TX FIFO is full */
while (uart->tx & TXDATA_FULL)
;
uart->tx = (int)c;
return c;
}
/**
* @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_fe310_poll_in(struct device *dev, unsigned char *c)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
uint32_t val = uart->rx;
if (val & RXDATA_EMPTY)
return -1;
*c = (unsigned char)(val & RXDATA_MASK);
return 0;
}
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
/**
* @brief Fill FIFO with data
*
* @param dev UART device struct
* @param tx_data Data to transmit
* @param size Number of bytes to send
*
* @return Number of bytes sent
*/
static int uart_fe310_fifo_fill(struct device *dev,
const uint8_t *tx_data,
int size)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
int i;
for (i = 0; i < size && !(uart->tx & TXDATA_FULL); i++)
uart->tx = (int)tx_data[i];
return i;
}
/**
* @brief Read data from FIFO
*
* @param dev UART device struct
* @param rxData Data container
* @param size Container size
*
* @return Number of bytes read
*/
static int uart_fe310_fifo_read(struct device *dev,
uint8_t *rx_data,
const int size)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
int i;
uint32_t val;
for (i = 0; i < size; i++) {
val = uart->rx;
if (val & RXDATA_EMPTY)
break;
rx_data[i] = (uint8_t)(val & RXDATA_MASK);
}
return i;
}
/**
* @brief Enable TX interrupt in ie register
*
* @param dev UART device struct
*
* @return N/A
*/
static void uart_fe310_irq_tx_enable(struct device *dev)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
uart->ie |= IE_TXWM;
}
/**
* @brief Disable TX interrupt in ie register
*
* @param dev UART device struct
*
* @return N/A
*/
static void uart_fe310_irq_tx_disable(struct device *dev)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
uart->ie &= ~IE_TXWM;
}
/**
* @brief Check if Tx IRQ has been raised
*
* @param dev UART device struct
*
* @return 1 if an IRQ is ready, 0 otherwise
*/
static int uart_fe310_irq_tx_ready(struct device *dev)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
return !!(uart->ip & IE_TXWM);
}
/**
* @brief Check if nothing remains to be transmitted
*
* @param dev UART device struct
*
* @return 1 if nothing remains to be transmitted, 0 otherwise
*/
static int uart_fe310_irq_tx_empty(struct device *dev)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
/*
* No TX EMTPY flag for this controller,
* just check if TX FIFO is not full
*/
return !(uart->tx & TXDATA_FULL);
}
/**
* @brief Enable RX interrupt in ie register
*
* @param dev UART device struct
*
* @return N/A
*/
static void uart_fe310_irq_rx_enable(struct device *dev)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
uart->ie |= IE_RXWM;
}
/**
* @brief Disable RX interrupt in ie register
*
* @param dev UART device struct
*
* @return N/A
*/
static void uart_fe310_irq_rx_disable(struct device *dev)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
uart->ie &= ~IE_RXWM;
}
/**
* @brief Check if Rx IRQ has been raised
*
* @param dev UART device struct
*
* @return 1 if an IRQ is ready, 0 otherwise
*/
static int uart_fe310_irq_rx_ready(struct device *dev)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
return !!(uart->ip & IE_RXWM);
}
/* No error interrupt for this controller */
static void uart_fe310_irq_err_enable(struct device *dev)
{
ARG_UNUSED(dev);
}
static void uart_fe310_irq_err_disable(struct device *dev)
{
ARG_UNUSED(dev);
}
/**
* @brief Check if any IRQ is pending
*
* @param dev UART device struct
*
* @return 1 if an IRQ is pending, 0 otherwise
*/
static int uart_fe310_irq_is_pending(struct device *dev)
{
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
return !!(uart->ip & (IE_RXWM | IE_TXWM));
}
static int uart_fe310_irq_update(struct device *dev)
{
return 1;
}
/**
* @brief Set the callback function pointer for IRQ.
*
* @param dev UART device struct
* @param cb Callback function pointer.
*
* @return N/A
*/
static void uart_fe310_irq_callback_set(struct device *dev,
uart_irq_callback_t cb)
{
struct uart_fe310_data *data = DEV_DATA(dev);
data->callback = cb;
}
static void uart_fe310_irq_handler(void *arg)
{
struct device *dev = (struct device *)arg;
struct uart_fe310_data *data = DEV_DATA(dev);
if (data->callback)
data->callback(dev);
}
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
static int uart_fe310_init(struct device *dev)
{
const struct uart_fe310_device_config * const cfg = DEV_CFG(dev);
volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
/* Enable TX and RX channels */
uart->txctrl = TXCTRL_TXEN | CTRL_CNT(cfg->rxcnt_irq);
uart->rxctrl = RXCTRL_RXEN | CTRL_CNT(cfg->txcnt_irq);
/* Set baud rate */
uart->div = cfg->sys_clk_freq / cfg->baud_rate - 1;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
/* Ensure that uart IRQ is disabled initially */
uart->ie = 0;
/* Setup IRQ handler */
cfg->cfg_func();
#endif
return 0;
}
static const struct uart_driver_api uart_fe310_driver_api = {
.poll_in = uart_fe310_poll_in,
.poll_out = uart_fe310_poll_out,
.err_check = NULL,
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.fifo_fill = uart_fe310_fifo_fill,
.fifo_read = uart_fe310_fifo_read,
.irq_tx_enable = uart_fe310_irq_tx_enable,
.irq_tx_disable = uart_fe310_irq_tx_disable,
.irq_tx_ready = uart_fe310_irq_tx_ready,
.irq_tx_empty = uart_fe310_irq_tx_empty,
.irq_rx_enable = uart_fe310_irq_rx_enable,
.irq_rx_disable = uart_fe310_irq_rx_disable,
.irq_rx_ready = uart_fe310_irq_rx_ready,
.irq_err_enable = uart_fe310_irq_err_enable,
.irq_err_disable = uart_fe310_irq_err_disable,
.irq_is_pending = uart_fe310_irq_is_pending,
.irq_update = uart_fe310_irq_update,
.irq_callback_set = uart_fe310_irq_callback_set,
#endif
};
#ifdef CONFIG_UART_FE310_PORT_0
static struct uart_fe310_data uart_fe310_data_0;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static void uart_fe310_irq_cfg_func_0(void);
#endif
static const struct uart_fe310_device_config uart_fe310_dev_cfg_0 = {
.port = FE310_UART_0_BASE_ADDR,
.sys_clk_freq = uart_fe310_port_0_clk_freq,
.baud_rate = CONFIG_UART_FE310_PORT_0_BAUD_RATE,
.rxcnt_irq = CONFIG_UART_FE310_PORT_0_RXCNT_IRQ,
.txcnt_irq = CONFIG_UART_FE310_PORT_0_TXCNT_IRQ,
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.cfg_func = uart_fe310_irq_cfg_func_0,
#endif
};
DEVICE_AND_API_INIT(uart_fe310_0, CONFIG_UART_FE310_PORT_0_NAME,
uart_fe310_init,
&uart_fe310_data_0, &uart_fe310_dev_cfg_0,
PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
(void *)&uart_fe310_driver_api);
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static void uart_fe310_irq_cfg_func_0(void)
{
IRQ_CONNECT(FE310_UART_0_IRQ,
CONFIG_UART_FE310_PORT_0_IRQ_PRIORITY,
uart_fe310_irq_handler, DEVICE_GET(uart_fe310_0),
0);
irq_enable(FE310_UART_0_IRQ);
}
#endif
#endif /* CONFIG_FE310_UART_0 */
#ifdef CONFIG_UART_FE310_PORT_1
static struct uart_fe310_data uart_fe310_data_1;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static void uart_fe310_irq_cfg_func_1(void);
#endif
static const struct uart_fe310_device_config uart_fe310_dev_cfg_1 = {
.port = FE310_UART_1_BASE_ADDR,
.sys_clk_freq = uart_fe310_port_1_clk_freq,
.baud_rate = CONFIG_UART_FE310_PORT_1_BAUD_RATE,
.rxcnt_irq = CONFIG_UART_FE310_PORT_1_RXCNT_IRQ,
.txcnt_irq = CONFIG_UART_FE310_PORT_1_TXCNT_IRQ,
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.cfg_func = uart_fe310_irq_cfg_func_1,
#endif
};
DEVICE_AND_API_INIT(uart_fe310_1, CONFIG_UART_FE310_PORT_1_NAME,
uart_fe310_init,
&uart_fe310_data_1, &uart_fe310_dev_cfg_1,
PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
(void *)&uart_fe310_driver_api);
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static void uart_fe310_irq_cfg_func_0(void)
{
IRQ_CONNECT(FE310_UART_1_IRQ,
CONFIG_UART_FE310_PORT_1_IRQ_PRIORITY,
uart_fe310_irq_handler, DEVICE_GET(uart_fe310_1),
0);
irq_enable(FE310_UART_1_IRQ);
}
#endif
#endif /* CONFIG_FE310_UART_1 */