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OpenCloudOS-Kernel/drivers/tty/serial/xilinx_uartps.c

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/*
* Xilinx PS UART driver
*
* 2011 (c) Xilinx Inc.
*
* This program is free software; you can redistribute it
* and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation;
* either version 2 of the License, or (at your option) any
* later version.
*
*/
#include <linux/platform_device.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/console.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/module.h>
#define XUARTPS_TTY_NAME "ttyPS"
#define XUARTPS_NAME "xuartps"
#define XUARTPS_MAJOR 0 /* use dynamic node allocation */
#define XUARTPS_MINOR 0 /* works best with devtmpfs */
#define XUARTPS_NR_PORTS 2
#define XUARTPS_FIFO_SIZE 16 /* FIFO size */
#define XUARTPS_REGISTER_SPACE 0xFFF
#define xuartps_readl(offset) ioread32(port->membase + offset)
#define xuartps_writel(val, offset) iowrite32(val, port->membase + offset)
/********************************Register Map********************************/
/** UART
*
* Register offsets for the UART.
*
*/
#define XUARTPS_CR_OFFSET 0x00 /* Control Register [8:0] */
#define XUARTPS_MR_OFFSET 0x04 /* Mode Register [10:0] */
#define XUARTPS_IER_OFFSET 0x08 /* Interrupt Enable [10:0] */
#define XUARTPS_IDR_OFFSET 0x0C /* Interrupt Disable [10:0] */
#define XUARTPS_IMR_OFFSET 0x10 /* Interrupt Mask [10:0] */
#define XUARTPS_ISR_OFFSET 0x14 /* Interrupt Status [10:0]*/
#define XUARTPS_BAUDGEN_OFFSET 0x18 /* Baud Rate Generator [15:0] */
#define XUARTPS_RXTOUT_OFFSET 0x1C /* RX Timeout [7:0] */
#define XUARTPS_RXWM_OFFSET 0x20 /* RX FIFO Trigger Level [5:0] */
#define XUARTPS_MODEMCR_OFFSET 0x24 /* Modem Control [5:0] */
#define XUARTPS_MODEMSR_OFFSET 0x28 /* Modem Status [8:0] */
#define XUARTPS_SR_OFFSET 0x2C /* Channel Status [11:0] */
#define XUARTPS_FIFO_OFFSET 0x30 /* FIFO [15:0] or [7:0] */
#define XUARTPS_BAUDDIV_OFFSET 0x34 /* Baud Rate Divider [7:0] */
#define XUARTPS_FLOWDEL_OFFSET 0x38 /* Flow Delay [15:0] */
#define XUARTPS_IRRX_PWIDTH_OFFSET 0x3C /* IR Minimum Received Pulse
Width [15:0] */
#define XUARTPS_IRTX_PWIDTH_OFFSET 0x40 /* IR Transmitted pulse
Width [7:0] */
#define XUARTPS_TXWM_OFFSET 0x44 /* TX FIFO Trigger Level [5:0] */
/** Control Register
*
* The Control register (CR) controls the major functions of the device.
*
* Control Register Bit Definitions
*/
#define XUARTPS_CR_STOPBRK 0x00000100 /* Stop TX break */
#define XUARTPS_CR_STARTBRK 0x00000080 /* Set TX break */
#define XUARTPS_CR_TX_DIS 0x00000020 /* TX disabled. */
#define XUARTPS_CR_TX_EN 0x00000010 /* TX enabled */
#define XUARTPS_CR_RX_DIS 0x00000008 /* RX disabled. */
#define XUARTPS_CR_RX_EN 0x00000004 /* RX enabled */
#define XUARTPS_CR_TXRST 0x00000002 /* TX logic reset */
#define XUARTPS_CR_RXRST 0x00000001 /* RX logic reset */
#define XUARTPS_CR_RST_TO 0x00000040 /* Restart Timeout Counter */
/** Mode Register
*
* The mode register (MR) defines the mode of transfer as well as the data
* format. If this register is modified during transmission or reception,
* data validity cannot be guaranteed.
*
* Mode Register Bit Definitions
*
*/
#define XUARTPS_MR_CLKSEL 0x00000001 /* Pre-scalar selection */
#define XUARTPS_MR_CHMODE_L_LOOP 0x00000200 /* Local loop back mode */
#define XUARTPS_MR_CHMODE_NORM 0x00000000 /* Normal mode */
#define XUARTPS_MR_STOPMODE_2_BIT 0x00000080 /* 2 stop bits */
#define XUARTPS_MR_STOPMODE_1_BIT 0x00000000 /* 1 stop bit */
#define XUARTPS_MR_PARITY_NONE 0x00000020 /* No parity mode */
#define XUARTPS_MR_PARITY_MARK 0x00000018 /* Mark parity mode */
#define XUARTPS_MR_PARITY_SPACE 0x00000010 /* Space parity mode */
#define XUARTPS_MR_PARITY_ODD 0x00000008 /* Odd parity mode */
#define XUARTPS_MR_PARITY_EVEN 0x00000000 /* Even parity mode */
#define XUARTPS_MR_CHARLEN_6_BIT 0x00000006 /* 6 bits data */
#define XUARTPS_MR_CHARLEN_7_BIT 0x00000004 /* 7 bits data */
#define XUARTPS_MR_CHARLEN_8_BIT 0x00000000 /* 8 bits data */
/** Interrupt Registers
*
* Interrupt control logic uses the interrupt enable register (IER) and the
* interrupt disable register (IDR) to set the value of the bits in the
* interrupt mask register (IMR). The IMR determines whether to pass an
* interrupt to the interrupt status register (ISR).
* Writing a 1 to IER Enables an interrupt, writing a 1 to IDR disables an
* interrupt. IMR and ISR are read only, and IER and IDR are write only.
* Reading either IER or IDR returns 0x00.
*
* All four registers have the same bit definitions.
*/
#define XUARTPS_IXR_TOUT 0x00000100 /* RX Timeout error interrupt */
#define XUARTPS_IXR_PARITY 0x00000080 /* Parity error interrupt */
#define XUARTPS_IXR_FRAMING 0x00000040 /* Framing error interrupt */
#define XUARTPS_IXR_OVERRUN 0x00000020 /* Overrun error interrupt */
#define XUARTPS_IXR_TXFULL 0x00000010 /* TX FIFO Full interrupt */
#define XUARTPS_IXR_TXEMPTY 0x00000008 /* TX FIFO empty interrupt */
#define XUARTPS_ISR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt */
#define XUARTPS_IXR_RXTRIG 0x00000001 /* RX FIFO trigger interrupt */
#define XUARTPS_IXR_RXFULL 0x00000004 /* RX FIFO full interrupt. */
#define XUARTPS_IXR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt. */
#define XUARTPS_IXR_MASK 0x00001FFF /* Valid bit mask */
/** Channel Status Register
*
* The channel status register (CSR) is provided to enable the control logic
* to monitor the status of bits in the channel interrupt status register,
* even if these are masked out by the interrupt mask register.
*/
#define XUARTPS_SR_RXEMPTY 0x00000002 /* RX FIFO empty */
#define XUARTPS_SR_TXEMPTY 0x00000008 /* TX FIFO empty */
#define XUARTPS_SR_TXFULL 0x00000010 /* TX FIFO full */
#define XUARTPS_SR_RXTRIG 0x00000001 /* Rx Trigger */
/**
* xuartps_isr - Interrupt handler
* @irq: Irq number
* @dev_id: Id of the port
*
* Returns IRQHANDLED
**/
static irqreturn_t xuartps_isr(int irq, void *dev_id)
{
struct uart_port *port = (struct uart_port *)dev_id;
struct tty_struct *tty;
unsigned long flags;
unsigned int isrstatus, numbytes;
unsigned int data;
char status = TTY_NORMAL;
/* Get the tty which could be NULL so don't assume it's valid */
tty = tty_port_tty_get(&port->state->port);
spin_lock_irqsave(&port->lock, flags);
/* Read the interrupt status register to determine which
* interrupt(s) is/are active.
*/
isrstatus = xuartps_readl(XUARTPS_ISR_OFFSET);
/* drop byte with parity error if IGNPAR specified */
if (isrstatus & port->ignore_status_mask & XUARTPS_IXR_PARITY)
isrstatus &= ~(XUARTPS_IXR_RXTRIG | XUARTPS_IXR_TOUT);
isrstatus &= port->read_status_mask;
isrstatus &= ~port->ignore_status_mask;
if ((isrstatus & XUARTPS_IXR_TOUT) ||
(isrstatus & XUARTPS_IXR_RXTRIG)) {
/* Receive Timeout Interrupt */
while ((xuartps_readl(XUARTPS_SR_OFFSET) &
XUARTPS_SR_RXEMPTY) != XUARTPS_SR_RXEMPTY) {
data = xuartps_readl(XUARTPS_FIFO_OFFSET);
port->icount.rx++;
if (isrstatus & XUARTPS_IXR_PARITY) {
port->icount.parity++;
status = TTY_PARITY;
} else if (isrstatus & XUARTPS_IXR_FRAMING) {
port->icount.frame++;
status = TTY_FRAME;
} else if (isrstatus & XUARTPS_IXR_OVERRUN)
port->icount.overrun++;
if (tty)
uart_insert_char(port, isrstatus,
XUARTPS_IXR_OVERRUN, data,
status);
}
spin_unlock(&port->lock);
if (tty)
tty_flip_buffer_push(tty);
spin_lock(&port->lock);
}
/* Dispatch an appropriate handler */
if ((isrstatus & XUARTPS_IXR_TXEMPTY) == XUARTPS_IXR_TXEMPTY) {
if (uart_circ_empty(&port->state->xmit)) {
xuartps_writel(XUARTPS_IXR_TXEMPTY,
XUARTPS_IDR_OFFSET);
} else {
numbytes = port->fifosize;
/* Break if no more data available in the UART buffer */
while (numbytes--) {
if (uart_circ_empty(&port->state->xmit))
break;
/* Get the data from the UART circular buffer
* and write it to the xuartps's TX_FIFO
* register.
*/
xuartps_writel(
port->state->xmit.buf[port->state->xmit.
tail], XUARTPS_FIFO_OFFSET);
port->icount.tx++;
/* Adjust the tail of the UART buffer and wrap
* the buffer if it reaches limit.
*/
port->state->xmit.tail =
(port->state->xmit.tail + 1) & \
(UART_XMIT_SIZE - 1);
}
if (uart_circ_chars_pending(
&port->state->xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
}
}
xuartps_writel(isrstatus, XUARTPS_ISR_OFFSET);
/* be sure to release the lock and tty before leaving */
spin_unlock_irqrestore(&port->lock, flags);
tty_kref_put(tty);
return IRQ_HANDLED;
}
/**
* xuartps_set_baud_rate - Calculate and set the baud rate
* @port: Handle to the uart port structure
* @baud: Baud rate to set
*
* Returns baud rate, requested baud when possible, or actual baud when there
* was too much error
**/
static unsigned int xuartps_set_baud_rate(struct uart_port *port,
unsigned int baud)
{
unsigned int sel_clk;
unsigned int calc_baud = 0;
unsigned int brgr_val, brdiv_val;
unsigned int bauderror;
/* Formula to obtain baud rate is
* baud_tx/rx rate = sel_clk/CD * (BDIV + 1)
* input_clk = (Uart User Defined Clock or Apb Clock)
* depends on UCLKEN in MR Reg
* sel_clk = input_clk or input_clk/8;
* depends on CLKS in MR reg
* CD and BDIV depends on values in
* baud rate generate register
* baud rate clock divisor register
*/
sel_clk = port->uartclk;
if (xuartps_readl(XUARTPS_MR_OFFSET) & XUARTPS_MR_CLKSEL)
sel_clk = sel_clk / 8;
/* Find the best values for baud generation */
for (brdiv_val = 4; brdiv_val < 255; brdiv_val++) {
brgr_val = sel_clk / (baud * (brdiv_val + 1));
if (brgr_val < 2 || brgr_val > 65535)
continue;
calc_baud = sel_clk / (brgr_val * (brdiv_val + 1));
if (baud > calc_baud)
bauderror = baud - calc_baud;
else
bauderror = calc_baud - baud;
/* use the values when percent error is acceptable */
if (((bauderror * 100) / baud) < 3) {
calc_baud = baud;
break;
}
}
/* Set the values for the new baud rate */
xuartps_writel(brgr_val, XUARTPS_BAUDGEN_OFFSET);
xuartps_writel(brdiv_val, XUARTPS_BAUDDIV_OFFSET);
return calc_baud;
}
/*----------------------Uart Operations---------------------------*/
/**
* xuartps_start_tx - Start transmitting bytes
* @port: Handle to the uart port structure
*
**/
static void xuartps_start_tx(struct uart_port *port)
{
unsigned int status, numbytes = port->fifosize;
if (uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port))
return;
status = xuartps_readl(XUARTPS_CR_OFFSET);
/* Set the TX enable bit and clear the TX disable bit to enable the
* transmitter.
*/
xuartps_writel((status & ~XUARTPS_CR_TX_DIS) | XUARTPS_CR_TX_EN,
XUARTPS_CR_OFFSET);
while (numbytes-- && ((xuartps_readl(XUARTPS_SR_OFFSET)
& XUARTPS_SR_TXFULL)) != XUARTPS_SR_TXFULL) {
/* Break if no more data available in the UART buffer */
if (uart_circ_empty(&port->state->xmit))
break;
/* Get the data from the UART circular buffer and
* write it to the xuartps's TX_FIFO register.
*/
xuartps_writel(
port->state->xmit.buf[port->state->xmit.tail],
XUARTPS_FIFO_OFFSET);
port->icount.tx++;
/* Adjust the tail of the UART buffer and wrap
* the buffer if it reaches limit.
*/
port->state->xmit.tail = (port->state->xmit.tail + 1) &
(UART_XMIT_SIZE - 1);
}
/* Enable the TX Empty interrupt */
xuartps_writel(XUARTPS_IXR_TXEMPTY, XUARTPS_IER_OFFSET);
if (uart_circ_chars_pending(&port->state->xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
}
/**
* xuartps_stop_tx - Stop TX
* @port: Handle to the uart port structure
*
**/
static void xuartps_stop_tx(struct uart_port *port)
{
unsigned int regval;
regval = xuartps_readl(XUARTPS_CR_OFFSET);
regval |= XUARTPS_CR_TX_DIS;
/* Disable the transmitter */
xuartps_writel(regval, XUARTPS_CR_OFFSET);
}
/**
* xuartps_stop_rx - Stop RX
* @port: Handle to the uart port structure
*
**/
static void xuartps_stop_rx(struct uart_port *port)
{
unsigned int regval;
regval = xuartps_readl(XUARTPS_CR_OFFSET);
regval |= XUARTPS_CR_RX_DIS;
/* Disable the receiver */
xuartps_writel(regval, XUARTPS_CR_OFFSET);
}
/**
* xuartps_tx_empty - Check whether TX is empty
* @port: Handle to the uart port structure
*
* Returns TIOCSER_TEMT on success, 0 otherwise
**/
static unsigned int xuartps_tx_empty(struct uart_port *port)
{
unsigned int status;
status = xuartps_readl(XUARTPS_ISR_OFFSET) & XUARTPS_IXR_TXEMPTY;
return status ? TIOCSER_TEMT : 0;
}
/**
* xuartps_break_ctl - Based on the input ctl we have to start or stop
* transmitting char breaks
* @port: Handle to the uart port structure
* @ctl: Value based on which start or stop decision is taken
*
**/
static void xuartps_break_ctl(struct uart_port *port, int ctl)
{
unsigned int status;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
status = xuartps_readl(XUARTPS_CR_OFFSET);
if (ctl == -1)
xuartps_writel(XUARTPS_CR_STARTBRK | status,
XUARTPS_CR_OFFSET);
else {
if ((status & XUARTPS_CR_STOPBRK) == 0)
xuartps_writel(XUARTPS_CR_STOPBRK | status,
XUARTPS_CR_OFFSET);
}
spin_unlock_irqrestore(&port->lock, flags);
}
/**
* xuartps_set_termios - termios operations, handling data length, parity,
* stop bits, flow control, baud rate
* @port: Handle to the uart port structure
* @termios: Handle to the input termios structure
* @old: Values of the previously saved termios structure
*
**/
static void xuartps_set_termios(struct uart_port *port,
struct ktermios *termios, struct ktermios *old)
{
unsigned int cval = 0;
unsigned int baud;
unsigned long flags;
unsigned int ctrl_reg, mode_reg;
spin_lock_irqsave(&port->lock, flags);
/* Empty the receive FIFO 1st before making changes */
while ((xuartps_readl(XUARTPS_SR_OFFSET) &
XUARTPS_SR_RXEMPTY) != XUARTPS_SR_RXEMPTY) {
xuartps_readl(XUARTPS_FIFO_OFFSET);
}
/* Disable the TX and RX to set baud rate */
xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS),
XUARTPS_CR_OFFSET);
/* Min baud rate = 6bps and Max Baud Rate is 10Mbps for 100Mhz clk */
baud = uart_get_baud_rate(port, termios, old, 0, 10000000);
baud = xuartps_set_baud_rate(port, baud);
if (tty_termios_baud_rate(termios))
tty_termios_encode_baud_rate(termios, baud, baud);
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
/* Set TX/RX Reset */
xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
(XUARTPS_CR_TXRST | XUARTPS_CR_RXRST),
XUARTPS_CR_OFFSET);
ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
/* Clear the RX disable and TX disable bits and then set the TX enable
* bit and RX enable bit to enable the transmitter and receiver.
*/
xuartps_writel(
(ctrl_reg & ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS))
| (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN),
XUARTPS_CR_OFFSET);
xuartps_writel(10, XUARTPS_RXTOUT_OFFSET);
port->read_status_mask = XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_RXTRIG |
XUARTPS_IXR_OVERRUN | XUARTPS_IXR_TOUT;
port->ignore_status_mask = 0;
if (termios->c_iflag & INPCK)
port->read_status_mask |= XUARTPS_IXR_PARITY |
XUARTPS_IXR_FRAMING;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= XUARTPS_IXR_PARITY |
XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN;
/* ignore all characters if CREAD is not set */
if ((termios->c_cflag & CREAD) == 0)
port->ignore_status_mask |= XUARTPS_IXR_RXTRIG |
XUARTPS_IXR_TOUT | XUARTPS_IXR_PARITY |
XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN;
mode_reg = xuartps_readl(XUARTPS_MR_OFFSET);
/* Handling Data Size */
switch (termios->c_cflag & CSIZE) {
case CS6:
cval |= XUARTPS_MR_CHARLEN_6_BIT;
break;
case CS7:
cval |= XUARTPS_MR_CHARLEN_7_BIT;
break;
default:
case CS8:
cval |= XUARTPS_MR_CHARLEN_8_BIT;
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= CS8;
break;
}
/* Handling Parity and Stop Bits length */
if (termios->c_cflag & CSTOPB)
cval |= XUARTPS_MR_STOPMODE_2_BIT; /* 2 STOP bits */
else
cval |= XUARTPS_MR_STOPMODE_1_BIT; /* 1 STOP bit */
if (termios->c_cflag & PARENB) {
/* Mark or Space parity */
if (termios->c_cflag & CMSPAR) {
if (termios->c_cflag & PARODD)
cval |= XUARTPS_MR_PARITY_MARK;
else
cval |= XUARTPS_MR_PARITY_SPACE;
} else if (termios->c_cflag & PARODD)
cval |= XUARTPS_MR_PARITY_ODD;
else
cval |= XUARTPS_MR_PARITY_EVEN;
} else
cval |= XUARTPS_MR_PARITY_NONE;
xuartps_writel(cval , XUARTPS_MR_OFFSET);
spin_unlock_irqrestore(&port->lock, flags);
}
/**
* xuartps_startup - Called when an application opens a xuartps port
* @port: Handle to the uart port structure
*
* Returns 0 on success, negative error otherwise
**/
static int xuartps_startup(struct uart_port *port)
{
unsigned int retval = 0, status = 0;
retval = request_irq(port->irq, xuartps_isr, 0, XUARTPS_NAME,
(void *)port);
if (retval)
return retval;
/* Disable the TX and RX */
xuartps_writel(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS,
XUARTPS_CR_OFFSET);
/* Set the Control Register with TX/RX Enable, TX/RX Reset,
* no break chars.
*/
xuartps_writel(XUARTPS_CR_TXRST | XUARTPS_CR_RXRST,
XUARTPS_CR_OFFSET);
status = xuartps_readl(XUARTPS_CR_OFFSET);
/* Clear the RX disable and TX disable bits and then set the TX enable
* bit and RX enable bit to enable the transmitter and receiver.
*/
xuartps_writel((status & ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS))
| (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN |
XUARTPS_CR_STOPBRK), XUARTPS_CR_OFFSET);
/* Set the Mode Register with normal mode,8 data bits,1 stop bit,
* no parity.
*/
xuartps_writel(XUARTPS_MR_CHMODE_NORM | XUARTPS_MR_STOPMODE_1_BIT
| XUARTPS_MR_PARITY_NONE | XUARTPS_MR_CHARLEN_8_BIT,
XUARTPS_MR_OFFSET);
/* Set the RX FIFO Trigger level to 14 assuming FIFO size as 16 */
xuartps_writel(14, XUARTPS_RXWM_OFFSET);
/* Receive Timeout register is enabled with value of 10 */
xuartps_writel(10, XUARTPS_RXTOUT_OFFSET);
/* Set the Interrupt Registers with desired interrupts */
xuartps_writel(XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_PARITY |
XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN |
XUARTPS_IXR_RXTRIG | XUARTPS_IXR_TOUT, XUARTPS_IER_OFFSET);
xuartps_writel(~(XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_PARITY |
XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN |
XUARTPS_IXR_RXTRIG | XUARTPS_IXR_TOUT), XUARTPS_IDR_OFFSET);
return retval;
}
/**
* xuartps_shutdown - Called when an application closes a xuartps port
* @port: Handle to the uart port structure
*
**/
static void xuartps_shutdown(struct uart_port *port)
{
int status;
/* Disable interrupts */
status = xuartps_readl(XUARTPS_IMR_OFFSET);
xuartps_writel(status, XUARTPS_IDR_OFFSET);
/* Disable the TX and RX */
xuartps_writel(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS,
XUARTPS_CR_OFFSET);
free_irq(port->irq, port);
}
/**
* xuartps_type - Set UART type to xuartps port
* @port: Handle to the uart port structure
*
* Returns string on success, NULL otherwise
**/
static const char *xuartps_type(struct uart_port *port)
{
return port->type == PORT_XUARTPS ? XUARTPS_NAME : NULL;
}
/**
* xuartps_verify_port - Verify the port params
* @port: Handle to the uart port structure
* @ser: Handle to the structure whose members are compared
*
* Returns 0 if success otherwise -EINVAL
**/
static int xuartps_verify_port(struct uart_port *port,
struct serial_struct *ser)
{
if (ser->type != PORT_UNKNOWN && ser->type != PORT_XUARTPS)
return -EINVAL;
if (port->irq != ser->irq)
return -EINVAL;
if (ser->io_type != UPIO_MEM)
return -EINVAL;
if (port->iobase != ser->port)
return -EINVAL;
if (ser->hub6 != 0)
return -EINVAL;
return 0;
}
/**
* xuartps_request_port - Claim the memory region attached to xuartps port,
* called when the driver adds a xuartps port via
* uart_add_one_port()
* @port: Handle to the uart port structure
*
* Returns 0, -ENOMEM if request fails
**/
static int xuartps_request_port(struct uart_port *port)
{
if (!request_mem_region(port->mapbase, XUARTPS_REGISTER_SPACE,
XUARTPS_NAME)) {
return -ENOMEM;
}
port->membase = ioremap(port->mapbase, XUARTPS_REGISTER_SPACE);
if (!port->membase) {
dev_err(port->dev, "Unable to map registers\n");
release_mem_region(port->mapbase, XUARTPS_REGISTER_SPACE);
return -ENOMEM;
}
return 0;
}
/**
* xuartps_release_port - Release the memory region attached to a xuartps
* port, called when the driver removes a xuartps
* port via uart_remove_one_port().
* @port: Handle to the uart port structure
*
**/
static void xuartps_release_port(struct uart_port *port)
{
release_mem_region(port->mapbase, XUARTPS_REGISTER_SPACE);
iounmap(port->membase);
port->membase = NULL;
}
/**
* xuartps_config_port - Configure xuartps, called when the driver adds a
* xuartps port
* @port: Handle to the uart port structure
* @flags: If any
*
**/
static void xuartps_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE && xuartps_request_port(port) == 0)
port->type = PORT_XUARTPS;
}
/**
* xuartps_get_mctrl - Get the modem control state
*
* @port: Handle to the uart port structure
*
* Returns the modem control state
*
**/
static unsigned int xuartps_get_mctrl(struct uart_port *port)
{
return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
}
static void xuartps_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
/* N/A */
}
static void xuartps_enable_ms(struct uart_port *port)
{
/* N/A */
}
/** The UART operations structure
*/
static struct uart_ops xuartps_ops = {
.set_mctrl = xuartps_set_mctrl,
.get_mctrl = xuartps_get_mctrl,
.enable_ms = xuartps_enable_ms,
.start_tx = xuartps_start_tx, /* Start transmitting */
.stop_tx = xuartps_stop_tx, /* Stop transmission */
.stop_rx = xuartps_stop_rx, /* Stop reception */
.tx_empty = xuartps_tx_empty, /* Transmitter busy? */
.break_ctl = xuartps_break_ctl, /* Start/stop
* transmitting break
*/
.set_termios = xuartps_set_termios, /* Set termios */
.startup = xuartps_startup, /* App opens xuartps */
.shutdown = xuartps_shutdown, /* App closes xuartps */
.type = xuartps_type, /* Set UART type */
.verify_port = xuartps_verify_port, /* Verification of port
* params
*/
.request_port = xuartps_request_port, /* Claim resources
* associated with a
* xuartps port
*/
.release_port = xuartps_release_port, /* Release resources
* associated with a
* xuartps port
*/
.config_port = xuartps_config_port, /* Configure when driver
* adds a xuartps port
*/
};
static struct uart_port xuartps_port[2];
/**
* xuartps_get_port - Configure the port from the platform device resource
* info
*
* Returns a pointer to a uart_port or NULL for failure
**/
static struct uart_port *xuartps_get_port(void)
{
struct uart_port *port;
int id;
/* Find the next unused port */
for (id = 0; id < XUARTPS_NR_PORTS; id++)
if (xuartps_port[id].mapbase == 0)
break;
if (id >= XUARTPS_NR_PORTS)
return NULL;
port = &xuartps_port[id];
/* At this point, we've got an empty uart_port struct, initialize it */
spin_lock_init(&port->lock);
port->membase = NULL;
port->iobase = 1; /* mark port in use */
port->irq = 0;
port->type = PORT_UNKNOWN;
port->iotype = UPIO_MEM32;
port->flags = UPF_BOOT_AUTOCONF;
port->ops = &xuartps_ops;
port->fifosize = XUARTPS_FIFO_SIZE;
port->line = id;
port->dev = NULL;
return port;
}
/*-----------------------Console driver operations--------------------------*/
#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
/**
* xuartps_console_wait_tx - Wait for the TX to be full
* @port: Handle to the uart port structure
*
**/
static void xuartps_console_wait_tx(struct uart_port *port)
{
while ((xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_TXEMPTY)
!= XUARTPS_SR_TXEMPTY)
barrier();
}
/**
* xuartps_console_putchar - write the character to the FIFO buffer
* @port: Handle to the uart port structure
* @ch: Character to be written
*
**/
static void xuartps_console_putchar(struct uart_port *port, int ch)
{
xuartps_console_wait_tx(port);
xuartps_writel(ch, XUARTPS_FIFO_OFFSET);
}
/**
* xuartps_console_write - perform write operation
* @port: Handle to the uart port structure
* @s: Pointer to character array
* @count: No of characters
**/
static void xuartps_console_write(struct console *co, const char *s,
unsigned int count)
{
struct uart_port *port = &xuartps_port[co->index];
unsigned long flags;
unsigned int imr;
int locked = 1;
if (oops_in_progress)
locked = spin_trylock_irqsave(&port->lock, flags);
else
spin_lock_irqsave(&port->lock, flags);
/* save and disable interrupt */
imr = xuartps_readl(XUARTPS_IMR_OFFSET);
xuartps_writel(imr, XUARTPS_IDR_OFFSET);
uart_console_write(port, s, count, xuartps_console_putchar);
xuartps_console_wait_tx(port);
/* restore interrupt state, it seems like there may be a h/w bug
* in that the interrupt enable register should not need to be
* written based on the data sheet
*/
xuartps_writel(~imr, XUARTPS_IDR_OFFSET);
xuartps_writel(imr, XUARTPS_IER_OFFSET);
if (locked)
spin_unlock_irqrestore(&port->lock, flags);
}
/**
* xuartps_console_setup - Initialize the uart to default config
* @co: Console handle
* @options: Initial settings of uart
*
* Returns 0, -ENODEV if no device
**/
static int __init xuartps_console_setup(struct console *co, char *options)
{
struct uart_port *port = &xuartps_port[co->index];
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (co->index < 0 || co->index >= XUARTPS_NR_PORTS)
return -EINVAL;
if (!port->mapbase) {
pr_debug("console on ttyPS%i not present\n", co->index);
return -ENODEV;
}
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct uart_driver xuartps_uart_driver;
static struct console xuartps_console = {
.name = XUARTPS_TTY_NAME,
.write = xuartps_console_write,
.device = uart_console_device,
.setup = xuartps_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1, /* Specified on the cmdline (e.g. console=ttyPS ) */
.data = &xuartps_uart_driver,
};
/**
* xuartps_console_init - Initialization call
*
* Returns 0 on success, negative error otherwise
**/
static int __init xuartps_console_init(void)
{
register_console(&xuartps_console);
return 0;
}
console_initcall(xuartps_console_init);
#endif /* CONFIG_SERIAL_XILINX_PS_UART_CONSOLE */
/** Structure Definitions
*/
static struct uart_driver xuartps_uart_driver = {
.owner = THIS_MODULE, /* Owner */
.driver_name = XUARTPS_NAME, /* Driver name */
.dev_name = XUARTPS_TTY_NAME, /* Node name */
.major = XUARTPS_MAJOR, /* Major number */
.minor = XUARTPS_MINOR, /* Minor number */
.nr = XUARTPS_NR_PORTS, /* Number of UART ports */
#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
.cons = &xuartps_console, /* Console */
#endif
};
/* ---------------------------------------------------------------------
* Platform bus binding
*/
/**
* xuartps_probe - Platform driver probe
* @pdev: Pointer to the platform device structure
*
* Returns 0 on success, negative error otherwise
**/
static int __devinit xuartps_probe(struct platform_device *pdev)
{
int rc;
struct uart_port *port;
struct resource *res, *res2;
int clk = 0;
#ifdef CONFIG_OF
const unsigned int *prop;
prop = of_get_property(pdev->dev.of_node, "clock", NULL);
if (prop)
clk = be32_to_cpup(prop);
#else
clk = *((unsigned int *)(pdev->dev.platform_data));
#endif
if (!clk) {
dev_err(&pdev->dev, "no clock specified\n");
return -ENODEV;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res2)
return -ENODEV;
/* Initialize the port structure */
port = xuartps_get_port();
if (!port) {
dev_err(&pdev->dev, "Cannot get uart_port structure\n");
return -ENODEV;
} else {
/* Register the port.
* This function also registers this device with the tty layer
* and triggers invocation of the config_port() entry point.
*/
port->mapbase = res->start;
port->irq = res2->start;
port->dev = &pdev->dev;
port->uartclk = clk;
dev_set_drvdata(&pdev->dev, port);
rc = uart_add_one_port(&xuartps_uart_driver, port);
if (rc) {
dev_err(&pdev->dev,
"uart_add_one_port() failed; err=%i\n", rc);
dev_set_drvdata(&pdev->dev, NULL);
return rc;
}
return 0;
}
}
/**
* xuartps_remove - called when the platform driver is unregistered
* @pdev: Pointer to the platform device structure
*
* Returns 0 on success, negative error otherwise
**/
static int __devexit xuartps_remove(struct platform_device *pdev)
{
struct uart_port *port = dev_get_drvdata(&pdev->dev);
int rc = 0;
/* Remove the xuartps port from the serial core */
if (port) {
rc = uart_remove_one_port(&xuartps_uart_driver, port);
dev_set_drvdata(&pdev->dev, NULL);
port->mapbase = 0;
}
return rc;
}
/**
* xuartps_suspend - suspend event
* @pdev: Pointer to the platform device structure
* @state: State of the device
*
* Returns 0
**/
static int xuartps_suspend(struct platform_device *pdev, pm_message_t state)
{
/* Call the API provided in serial_core.c file which handles
* the suspend.
*/
uart_suspend_port(&xuartps_uart_driver, &xuartps_port[pdev->id]);
return 0;
}
/**
* xuartps_resume - Resume after a previous suspend
* @pdev: Pointer to the platform device structure
*
* Returns 0
**/
static int xuartps_resume(struct platform_device *pdev)
{
uart_resume_port(&xuartps_uart_driver, &xuartps_port[pdev->id]);
return 0;
}
/* Match table for of_platform binding */
#ifdef CONFIG_OF
static struct of_device_id xuartps_of_match[] __devinitdata = {
{ .compatible = "xlnx,xuartps", },
{}
};
MODULE_DEVICE_TABLE(of, xuartps_of_match);
#else
#define xuartps_of_match NULL
#endif
static struct platform_driver xuartps_platform_driver = {
.probe = xuartps_probe, /* Probe method */
.remove = __exit_p(xuartps_remove), /* Detach method */
.suspend = xuartps_suspend, /* Suspend */
.resume = xuartps_resume, /* Resume after a suspend */
.driver = {
.owner = THIS_MODULE,
.name = XUARTPS_NAME, /* Driver name */
.of_match_table = xuartps_of_match,
},
};
/* ---------------------------------------------------------------------
* Module Init and Exit
*/
/**
* xuartps_init - Initial driver registration call
*
* Returns whether the registration was successful or not
**/
static int __init xuartps_init(void)
{
int retval = 0;
/* Register the xuartps driver with the serial core */
retval = uart_register_driver(&xuartps_uart_driver);
if (retval)
return retval;
/* Register the platform driver */
retval = platform_driver_register(&xuartps_platform_driver);
if (retval)
uart_unregister_driver(&xuartps_uart_driver);
return retval;
}
/**
* xuartps_exit - Driver unregistration call
**/
static void __exit xuartps_exit(void)
{
/* The order of unregistration is important. Unregister the
* UART driver before the platform driver crashes the system.
*/
/* Unregister the platform driver */
platform_driver_unregister(&xuartps_platform_driver);
/* Unregister the xuartps driver */
uart_unregister_driver(&xuartps_uart_driver);
}
module_init(xuartps_init);
module_exit(xuartps_exit);
MODULE_DESCRIPTION("Driver for PS UART");
MODULE_AUTHOR("Xilinx Inc.");
MODULE_LICENSE("GPL");
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