--- /dev/null
+/*
+ * 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_core.h>
+#include <linux/console.h>
+#include <linux/serial.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/of.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");
projects / firefly-linux-kernel-4.4.55.git / commitdiff