Home
Reading
Searching
Subscribe
Sponsors
Statistics
Posting
Contact
Spam
Lists
Links
About
Hosting
Filtering
Features Download
Marketing
Archives
FAQ
Blog
 
Gmane
From: John Linn <john.linn <at> xilinx.com>
Subject: [PATCH V2] tty/serial: add support for Xilinx PS UART
Newsgroups: gmane.linux.serial
Date: Wednesday 20th April 2011 19:03:15 UTC (over 5 years ago)
The Xilinx PS Uart is used on the new ARM based SoC. This
UART is not compatible with others such that a seperate
driver is required.

Signed-off-by: John Linn <[email protected]>
---

V2 Changes

Updated based on Alan Cox and Greg KH comments. Thanks for their input. 
I hope I corrected everything as expected.

1. Now using dynamic device nodes so Doc*/devices.txt removed from patch.
2. Other minor updates based on Alan's input.

 drivers/tty/serial/Kconfig         |   13 +
 drivers/tty/serial/Makefile        |    1 +
 drivers/tty/serial/xilinx_uartps.c | 1121
++++++++++++++++++++++++++++++++++++
 include/linux/serial_core.h        |    3 +
 4 files changed, 1138 insertions(+), 0 deletions(-)
 create mode 100644 drivers/tty/serial/xilinx_uartps.c

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 80484af..84876ec 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1612,4 +1612,17 @@ config SERIAL_MXS_AUART_CONSOLE
 	help
 	  Enable a MXS AUART port to be the system console.
 
+config SERIAL_XILINX_PS_UART
+	tristate "Xilinx PS UART support"
+	select SERIAL_CORE
+	help
+	  This driver supports the Xilinx PS UART port.
+
+config SERIAL_XILINX_PS_UART_CONSOLE
+	bool "Xilinx PS UART console support"
+	depends on SERIAL_XILINX_PS_UART=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Enable a Xilinx PS UART port to be the system console.
+
 endmenu
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index fee0690..aafddf1 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -94,3 +94,4 @@ obj-$(CONFIG_SERIAL_IFX6X60)  	+= ifx6x60.o
 obj-$(CONFIG_SERIAL_PCH_UART)	+= pch_uart.o
 obj-$(CONFIG_SERIAL_MSM_SMD)	+= msm_smd_tty.o
 obj-$(CONFIG_SERIAL_MXS_AUART) += mxs-auart.o
+obj-$(CONFIG_SERIAL_XILINX_PS_UART) += xilinx_uartps.o
diff --git a/drivers/tty/serial/xilinx_uartps.c
b/drivers/tty/serial/xilinx_uartps.c
new file mode 100644
index 0000000..814fb5b
--- /dev/null
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -0,0 +1,1121 @@
+/*
+ * 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 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#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
+ *
+ **/
+static void xuartps_set_baud_rate(struct uart_port *port, unsigned int
baud)
+{
+	unsigned int sel_clk;
+	unsigned int calc_baud;
+	unsigned int brgr_val, brdiv_val;
+	unsigned int bauderror, percent_err = 100;
+
+	/* 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;
+
+	/* Check for the values of baud clk divisor value ranging from 4 to 255
+	 * where the percent_err for the given baud rate is acceptable.
+	 */
+	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;
+
+		percent_err = (bauderror * 100) / baud;
+		if (percent_err < 3)
+			break;
+	}
+
+	if (percent_err >= 3)
+		dev_err(port->dev, "Error too large, baud rate not set\n");
+	else {
+		/* Set the values for the new baud rate */
+		xuartps_writel(brgr_val, XUARTPS_BAUDGEN_OFFSET);
+		xuartps_writel(brdiv_val, XUARTPS_BAUDDIV_OFFSET);
+
+	}
+}
+
+
+/*----------------------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);
+	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	= NO_IRQ;
+	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);
+#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 */
+#ifdef CONFIG_OF
+		.of_match_table = xuartps_of_match,
+#endif
+		},
+};
+
+
+/* ---------------------------------------------------------------------
+ * 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");
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 758c5b0..95d479b 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -202,6 +202,9 @@
 /* VIA VT8500 SoC */
 #define PORT_VT8500	97
 
+/* Xilinx PSS UART */
+#define PORT_XUARTPS	98
+
 #ifdef __KERNEL__
 
 #include 
-- 
1.5.4.7



This email and any attachments are intended for the sole use of the named
recipient(s) and contain(s) confidential information that may be
proprietary, privileged or copyrighted under applicable law. If you are not
the intended recipient, do not read, copy, or forward this email message or
any attachments. Delete this email message and any attachments immediately.


--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
 
CD: 18ms