zephyr/drivers/serial/uart_pl011.c

517 lines
13 KiB
C

/*
* Copyright (c) 2018 Linaro Limited
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel.h>
#include <arch/cpu.h>
#include <init.h>
#include <device.h>
#include <soc.h>
#include <drivers/uart.h>
/*
* UART PL011 register map structure
*/
struct pl011_regs {
u32_t dr; /* data register */
union {
u32_t rsr;
u32_t ecr;
};
u32_t reserved_0[4];
u32_t fr; /* flags register */
u32_t reserved_1;
u32_t ilpr;
u32_t ibrd;
u32_t fbrd;
u32_t lcr_h;
u32_t cr;
u32_t ifls;
u32_t imsc;
u32_t ris;
u32_t mis;
u32_t icr;
u32_t dmacr;
};
/* Device data structure */
struct pl011_data {
u32_t baud_rate; /* Baud rate */
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
uart_irq_callback_user_data_t irq_cb;
void *irq_cb_data;
#endif
};
#define PL011_BIT_MASK(x, y) (((2 << x) - 1) << y)
/* PL011 Uart Flags Register */
#define PL011_FR_CTS BIT(0) /* clear to send - inverted */
#define PL011_FR_DSR BIT(1) /* data set ready - inverted */
#define PL011_FR_DCD BIT(2) /* data carrier detect - inverted */
#define PL011_FR_BUSY BIT(3) /* busy transmitting data */
#define PL011_FR_RXFE BIT(4) /* receive FIFO empty */
#define PL011_FR_TXFF BIT(5) /* transmit FIFO full */
#define PL011_FR_RXFF BIT(6) /* receive FIFO full */
#define PL011_FR_TXFE BIT(7) /* transmit FIFO empty */
#define PL011_FR_RI BIT(8) /* ring indicator - inverted */
/* PL011 Integer baud rate register */
#define PL011_IBRD_BAUD_DIVINT_MASK 0xff /* 16 bits of divider */
/* PL011 Fractional baud rate register */
#define PL011_FBRD_BAUD_DIVFRAC 0x3f
#define PL011_FBRD_WIDTH 6u
/* PL011 Receive status register / error clear register */
#define PL011_RSR_ECR_FE BIT(0) /* framing error */
#define PL011_RSR_ECR_PE BIT(1) /* parity erorr */
#define PL011_RSR_ECR_BE BIT(2) /* break error */
#define PL011_RSR_ECR_OE BIT(3) /* overrun error */
#define PL011_RSR_ERROR_MASK (PL011_RSR_ECR_FE | PL011_RSR_ECR_PE | \
PL011_RSR_ECR_BE | PL011_RSR_ECR_OE)
/* PL011 Line Control Register */
#define PL011_LCRH_BRK BIT(0) /* send break */
#define PL011_LCRH_PEN BIT(1) /* enable parity */
#define PL011_LCRH_EPS BIT(2) /* select even parity */
#define PL011_LCRH_STP2 BIT(3) /* select two stop bits */
#define PL011_LCRH_FEN BIT(4) /* enable FIFOs */
#define PL011_LCRH_WLEN_SHIFT 5 /* word length */
#define PL011_LCRH_WLEN_WIDTH 2
#define PL011_LCRH_SPS BIT(7) /* stick parity bit */
#define PL011_LCRH_WLEN_SIZE(x) (x - 5)
#define PL011_LCRH_FORMAT_MASK (PL011_LCRH_PEN | PL011_LCRH_EPS | \
PL011_LCRH_SPS | \
PL011_BIT_MASK(PL011_LCRH_WLEN_WIDTH, PL011_LCRH_WLEN_SHIFT))
#define PL011_LCRH_PARTIY_EVEN (PL011_LCRH_PEN | PL011_LCRH_EPS)
#define PL011_LCRH_PARITY_ODD (PL011_LCRH_PEN)
#define PL011_LCRH_PARITY_NONE (0)
/* PL011 Control Register */
#define PL011_CR_UARTEN BIT(0) /* enable uart operations */
#define PL011_CR_SIREN BIT(1) /* enable IrDA SIR */
#define PL011_CR_SIRLP BIT(2) /* IrDA SIR low power mode */
#define PL011_CR_LBE BIT(7) /* loop back enable */
#define PL011_CR_TXE BIT(8) /* transmit enable */
#define PL011_CR_RXE BIT(9) /* receive enable */
#define PL011_CR_DTR BIT(10) /* data transmit ready */
#define PL011_CR_RTS BIT(11) /* request to send */
#define PL011_CR_Out1 BIT(12)
#define PL011_CR_Out2 BIT(13)
#define PL011_CR_RTSEn BIT(14) /* RTS hw flow control enable */
#define PL011_CR_CTSEn BIT(15) /* CTS hw flow control enable */
/* PL011 Interrupt Fifo Level Select Register */
#define PL011_IFLS_TXIFLSEL_SHIFT 0 /* bits 2:0 */
#define PL011_IFLS_TXIFLSEL_WIDTH 3
#define PL011_IFLS_RXIFLSEL_SHIFT 3 /* bits 5:3 */
#define PL011_IFLS_RXIFLSEL_WIDTH 3
/* PL011 Interrupt Mask Set/Clear Register */
#define PL011_IMSC_RIMIM BIT(0) /* RTR modem interrupt mask */
#define PL011_IMSC_CTSMIM BIT(1) /* CTS modem interrupt mask */
#define PL011_IMSC_DCDMIM BIT(2) /* DCD modem interrupt mask */
#define PL011_IMSC_DSRMIM BIT(3) /* DSR modem interrupt mask */
#define PL011_IMSC_RXIM BIT(4) /* receive interrupt mask */
#define PL011_IMSC_TXIM BIT(5) /* transmit interrupt mask */
#define PL011_IMSC_RTIM BIT(6) /* receive timeout interrupt mask */
#define PL011_IMSC_FEIM BIT(7) /* framine error interrupt mask */
#define PL011_IMSC_PEIM BIT(8) /* parity error interrupt mask */
#define PL011_IMSC_BEIM BIT(9) /* break error interrupt mask */
#define PL011_IMSC_OEIM BIT(10) /* overrun error interrutpt mask */
#define PL011_IMSC_ERROR_MASK (PL011_IMSC_FEIM | \
PL011_IMSC_PEIM | PL011_IMSC_BEIM | \
PL011_IMSC_OEIM)
#define PL011_IMSC_MASK_ALL (PL011_IMSC_OEIM | PL011_IMSC_BEIM | \
PL011_IMSC_PEIM | PL011_IMSC_FEIM | \
PL011_IMSC_RIMIM | PL011_IMSC_CTSMIM | \
PL011_IMSC_DCDMIM | PL011_IMSC_DSRMIM | \
PL011_IMSC_RXIM | PL011_IMSC_TXIM | \
PL011_IMSC_RTIM)
#define DEV_CFG(dev) \
((const struct uart_device_config * const)(dev)->config->config_info)
#define DEV_DATA(dev) \
((struct pl011_data *)(dev)->driver_data)
#define PL011_REGS(dev) \
((volatile struct pl011_regs *)(DEV_CFG(dev))->base)
static void pl011_enable(struct device *dev)
{
PL011_REGS(dev)->cr |= PL011_CR_UARTEN;
}
static void pl011_disable(struct device *dev)
{
PL011_REGS(dev)->cr &= ~PL011_CR_UARTEN;
}
static void pl011_enable_fifo(struct device *dev)
{
PL011_REGS(dev)->lcr_h |= PL011_LCRH_FEN;
}
static void pl011_disable_fifo(struct device *dev)
{
PL011_REGS(dev)->lcr_h &= ~PL011_LCRH_FEN;
}
static int pl011_set_baudrate(struct device *dev,
u32_t clk, u32_t baudrate)
{
/* Avoiding float calculations, bauddiv is left shifted by 6 */
u64_t bauddiv = (((u64_t)clk) << PL011_FBRD_WIDTH)
/ (baudrate * 16U);
/* Valid bauddiv value
* uart_clk (min) >= 16 x baud_rate (max)
* uart_clk (max) <= 16 x 65535 x baud_rate (min)
*/
if ((bauddiv < (1u << PL011_FBRD_WIDTH))
|| (bauddiv > (65535u << PL011_FBRD_WIDTH))) {
return -EINVAL;
}
PL011_REGS(dev)->ibrd = bauddiv >> PL011_FBRD_WIDTH;
PL011_REGS(dev)->fbrd = bauddiv & ((1u << PL011_FBRD_WIDTH) - 1u);
__DMB();
/* In order to internally update the contents of ibrd or fbrd, a
* lcr_h write must always be performed at the end
* ARM DDI 0183F, Pg 3-13
*/
PL011_REGS(dev)->lcr_h = PL011_REGS(dev)->lcr_h;
return 0;
}
static bool pl011_is_readable(struct device *dev)
{
if ((PL011_REGS(dev)->cr & PL011_CR_UARTEN) &&
(PL011_REGS(dev)->cr & PL011_CR_RXE) &&
((PL011_REGS(dev)->fr & PL011_FR_RXFE) == 0U)) {
return true;
}
return false;
}
static int pl011_poll_in(struct device *dev, unsigned char *c)
{
if (!pl011_is_readable(dev)) {
return -1;
}
/* got a character */
*c = (unsigned char)PL011_REGS(dev)->dr;
return PL011_REGS(dev)->rsr & PL011_RSR_ERROR_MASK;
}
static void pl011_poll_out(struct device *dev,
unsigned char c)
{
/* Wait for space in FIFO */
while (PL011_REGS(dev)->fr & PL011_FR_TXFF) {
; /* Wait */
}
/* Send a character */
PL011_REGS(dev)->dr = (u32_t)c;
}
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static int pl011_fifo_fill(struct device *dev,
const u8_t *tx_data, int len)
{
u8_t num_tx = 0U;
while (!(PL011_REGS(dev)->fr & PL011_FR_TXFF) &&
(len - num_tx > 0)) {
PL011_REGS(dev)->dr = tx_data[num_tx++];
}
return num_tx;
}
static int pl011_fifo_read(struct device *dev,
u8_t *rx_data, const int len)
{
u8_t num_rx = 0U;
while ((len - num_rx > 0) &&
!(PL011_REGS(dev)->fr & PL011_FR_RXFE)) {
rx_data[num_rx++] = PL011_REGS(dev)->dr;
}
return num_rx;
}
static void pl011_irq_tx_enable(struct device *dev)
{
PL011_REGS(dev)->imsc |= PL011_IMSC_TXIM;
}
static void pl011_irq_tx_disable(struct device *dev)
{
PL011_REGS(dev)->imsc &= ~PL011_IMSC_TXIM;
}
static int pl011_irq_tx_complete(struct device *dev)
{
/* check for TX FIFO empty */
return PL011_REGS(dev)->fr & PL011_FR_TXFE;
}
static int pl011_irq_tx_ready(struct device *dev)
{
return ((PL011_REGS(dev)->cr & PL011_CR_TXE) &&
(PL011_REGS(dev)->imsc & PL011_IMSC_TXIM) &&
pl011_irq_tx_complete(dev));
}
static void pl011_irq_rx_enable(struct device *dev)
{
PL011_REGS(dev)->imsc |= PL011_IMSC_RXIM |
PL011_IMSC_RTIM;
}
static void pl011_irq_rx_disable(struct device *dev)
{
PL011_REGS(dev)->imsc &= ~(PL011_IMSC_RXIM |
PL011_IMSC_RTIM);
}
static int pl011_irq_rx_ready(struct device *dev)
{
return ((PL011_REGS(dev)->cr & PL011_CR_RXE) &&
(PL011_REGS(dev)->imsc & PL011_IMSC_RXIM) &&
(!(PL011_REGS(dev)->fr & PL011_FR_RXFE)));
}
static void pl011_irq_err_enable(struct device *dev)
{
/* enable framing, parity, break, and overrun */
PL011_REGS(dev)->imsc |= PL011_IMSC_ERROR_MASK;
}
static void pl011_irq_err_disable(struct device *dev)
{
PL011_REGS(dev)->imsc &= ~PL011_IMSC_ERROR_MASK;
}
static int pl011_irq_is_pending(struct device *dev)
{
return pl011_irq_rx_ready(dev) || pl011_irq_tx_ready(dev);
}
static int pl011_irq_update(struct device *dev)
{
return 1;
}
static void pl011_irq_callback_set(struct device *dev,
uart_irq_callback_user_data_t cb,
void *cb_data)
{
DEV_DATA(dev)->irq_cb = cb;
DEV_DATA(dev)->irq_cb_data = cb_data;
}
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
static const struct uart_driver_api pl011_driver_api = {
.poll_in = pl011_poll_in,
.poll_out = pl011_poll_out,
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.fifo_fill = pl011_fifo_fill,
.fifo_read = pl011_fifo_read,
.irq_tx_enable = pl011_irq_tx_enable,
.irq_tx_disable = pl011_irq_tx_disable,
.irq_tx_ready = pl011_irq_tx_ready,
.irq_rx_enable = pl011_irq_rx_enable,
.irq_rx_disable = pl011_irq_rx_disable,
.irq_tx_complete = pl011_irq_tx_complete,
.irq_rx_ready = pl011_irq_rx_ready,
.irq_err_enable = pl011_irq_err_enable,
.irq_err_disable = pl011_irq_err_disable,
.irq_is_pending = pl011_irq_is_pending,
.irq_update = pl011_irq_update,
.irq_callback_set = pl011_irq_callback_set,
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
};
static int pl011_init(struct device *dev)
{
int ret;
u32_t lcrh;
/* disable the uart */
pl011_disable(dev);
pl011_disable_fifo(dev);
/* Set baud rate */
ret = pl011_set_baudrate(dev, DEV_CFG(dev)->sys_clk_freq,
DEV_DATA(dev)->baud_rate);
if (ret != 0) {
return ret;
}
/* Setting the default character format */
lcrh = PL011_REGS(dev)->lcr_h & ~(PL011_LCRH_FORMAT_MASK);
lcrh &= ~(BIT(0) | BIT(7));
lcrh |= PL011_LCRH_WLEN_SIZE(8) << PL011_LCRH_WLEN_SHIFT;
PL011_REGS(dev)->lcr_h = lcrh;
/* Enabling the FIFOs */
pl011_enable_fifo(dev);
/* initialize all IRQs as masked */
PL011_REGS(dev)->imsc = 0U;
PL011_REGS(dev)->icr = PL011_IMSC_MASK_ALL;
PL011_REGS(dev)->dmacr = 0U;
__ISB();
PL011_REGS(dev)->cr &= ~(BIT(14) | BIT(15) | BIT(1));
PL011_REGS(dev)->cr |= PL011_CR_RXE | PL011_CR_TXE;
__ISB();
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
DEV_CFG(dev)->irq_config_func(dev);
#endif
pl011_enable(dev);
return 0;
}
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
void pl011_isr(void *arg)
{
struct device *dev = arg;
struct pl011_data *data = DEV_DATA(dev);
/* Verify if the callback has been registered */
if (data->irq_cb) {
data->irq_cb(data->irq_cb_data);
}
}
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
#ifdef CONFIG_UART_PL011_PORT0
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static void pl011_irq_config_func_0(struct device *dev);
#endif
static struct uart_device_config pl011_cfg_port_0 = {
.base = (u8_t *)DT_PL011_PORT0_BASE_ADDRESS,
.sys_clk_freq = DT_PL011_PORT0_CLOCK_FREQUENCY,
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.irq_config_func = pl011_irq_config_func_0,
#endif
};
static struct pl011_data pl011_data_port_0 = {
.baud_rate = DT_PL011_PORT0_BAUD_RATE,
};
DEVICE_AND_API_INIT(pl011_port_0,
DT_PL011_PORT0_NAME,
&pl011_init,
&pl011_data_port_0,
&pl011_cfg_port_0, PRE_KERNEL_1,
CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&pl011_driver_api);
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static void pl011_irq_config_func_0(struct device *dev)
{
IRQ_CONNECT(DT_PL011_PORT0_IRQ_TX,
DT_PL011_PORT0_IRQ_PRI,
pl011_isr,
DEVICE_GET(pl011_port_0),
0);
irq_enable(DT_PL011_PORT0_IRQ_TX);
IRQ_CONNECT(DT_PL011_PORT0_IRQ_RX,
DT_PL011_PORT0_IRQ_PRI,
pl011_isr,
DEVICE_GET(pl011_port_0),
0);
irq_enable(DT_PL011_PORT0_IRQ_RX);
IRQ_CONNECT(DT_PL011_PORT0_IRQ_RXTIM,
DT_PL011_PORT0_IRQ_PRI,
pl011_isr,
DEVICE_GET(pl011_port_0),
0);
irq_enable(DT_PL011_PORT0_IRQ_RXTIM);
}
#endif
#endif /* CONFIG_UART_PL011_PORT0 */
#ifdef CONFIG_UART_PL011_PORT1
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static void pl011_irq_config_func_1(struct device *dev);
#endif
static struct uart_device_config pl011_cfg_port_1 = {
.base = (u8_t *)DT_PL011_PORT1_BASE_ADDRESS,
.sys_clk_freq = DT_PL011_PORT1_CLOCK_FREQUENCY,
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.irq_config_func = pl011_irq_config_func_1,
#endif
};
static struct pl011_data pl011_data_port_1 = {
.baud_rate = DT_PL011_PORT1_BAUD_RATE,
};
DEVICE_AND_API_INIT(pl011_port_1,
DT_PL011_PORT1_NAME,
&pl011_init,
&pl011_data_port_1,
&pl011_cfg_port_1, PRE_KERNEL_1,
CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&pl011_driver_api);
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static void pl011_irq_config_func_1(struct device *dev)
{
IRQ_CONNECT(DT_PL011_PORT1_IRQ_TX,
DT_PL011_PORT1_IRQ_PRI,
pl011_isr,
DEVICE_GET(pl011_port_1),
0);
irq_enable(DT_PL011_PORT1_IRQ_TX);
IRQ_CONNECT(DT_PL011_PORT1_IRQ_RX,
DT_PL011_PORT1_IRQ_PRI,
pl011_isr,
DEVICE_GET(pl011_port_1),
0);
irq_enable(DT_PL011_PORT1_IRQ_RX);
IRQ_CONNECT(DT_PL011_PORT1_IRQ_RXTIM,
DT_PL011_PORT1_IRQ_PRI,
pl011_isr,
DEVICE_GET(pl011_port_1),
0);
irq_enable(DT_PL011_PORT1_IRQ_RXTIM);
}
#endif
#endif /* CONFIG_UART_PL011_PORT1 */