[POWERPC] qe-uart: add support for Freescale QUICCEngine UART

Add file ucc_uart.c, a serial device driver for the Freescale QUICCEngine.
Update the Kconfig and Makefile accordingly.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 1514 insertions, 0 deletions

diff --git a/drivers/serial/ucc_uart.c b/drivers/serial/ucc_uart.c
new file mode 100644
index 0000000..e0994f0
--- /dev/null
+++ b/drivers/serial/ucc_uart.c
@@ -0,0 +1,1514 @@
+/*
+ * Freescale QUICC Engine UART device driver
+ *
+ * Author: Timur Tabi <timur@freescale.com>
+ *
+ * Copyright 2007 Freescale Semiconductor, Inc.  This file is licensed under
+ * the terms of the GNU General Public License version 2.  This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ *
+ * This driver adds support for UART devices via Freescale's QUICC Engine
+ * found on some Freescale SOCs.
+ *
+ * If Soft-UART support is needed but not already present, then this driver
+ * will request and upload the "Soft-UART" microcode upon probe.  The
+ * filename of the microcode should be fsl_qe_ucode_uart_X_YZ.bin, where "X"
+ * is the name of the SOC (e.g. 8323), and YZ is the revision of the SOC,
+ * (e.g. "11" for 1.1).
+ */
+
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/io.h>
+#include <linux/of_platform.h>
+#include <linux/dma-mapping.h>
+
+#include <linux/fs_uart_pd.h>
+#include <asm/ucc_slow.h>
+
+#include <linux/firmware.h>
+#include <asm/reg.h>
+
+/*
+ * The GUMR flag for Soft UART.  This would normally be defined in qe.h,
+ * but Soft-UART is a hack and we want to keep everything related to it in
+ * this file.
+ */
+#define UCC_SLOW_GUMR_H_SUART   	0x00004000      /* Soft-UART */
+
+/*
+ * soft_uart is 1 if we need to use Soft-UART mode
+ */
+static int soft_uart;
+/*
+ * firmware_loaded is 1 if the firmware has been loaded, 0 otherwise.
+ */
+static int firmware_loaded;
+
+/* Enable this macro to configure all serial ports in internal loopback
+   mode */
+/* #define LOOPBACK */
+
+/* The major and minor device numbers are defined in
+ * http://www.lanana.org/docs/device-list/devices-2.6+.txt.  For the QE
+ * UART, we have major number 204 and minor numbers 46 - 49, which are the
+ * same as for the CPM2.  This decision was made because no Freescale part
+ * has both a CPM and a QE.
+ */
+#define SERIAL_QE_MAJOR 204
+#define SERIAL_QE_MINOR 46
+
+/* Since we only have minor numbers 46 - 49, there is a hard limit of 4 ports */
+#define UCC_MAX_UART    4
+
+/* The number of buffer descriptors for receiving characters. */
+#define RX_NUM_FIFO     4
+
+/* The number of buffer descriptors for transmitting characters. */
+#define TX_NUM_FIFO     4
+
+/* The maximum size of the character buffer for a single RX BD. */
+#define RX_BUF_SIZE     32
+
+/* The maximum size of the character buffer for a single TX BD. */
+#define TX_BUF_SIZE     32
+
+/*
+ * The number of jiffies to wait after receiving a close command before the
+ * device is actually closed.  This allows the last few characters to be
+ * sent over the wire.
+ */
+#define UCC_WAIT_CLOSING 100
+
+struct ucc_uart_pram {
+	struct ucc_slow_pram common;
+	u8 res1[8];     	/* reserved */
+	__be16 maxidl;  	/* Maximum idle chars */
+	__be16 idlc;    	/* temp idle counter */
+	__be16 brkcr;   	/* Break count register */
+	__be16 parec;   	/* receive parity error counter */
+	__be16 frmec;   	/* receive framing error counter */
+	__be16 nosec;   	/* receive noise counter */
+	__be16 brkec;   	/* receive break condition counter */
+	__be16 brkln;   	/* last received break length */
+	__be16 uaddr[2];	/* UART address character 1 & 2 */
+	__be16 rtemp;   	/* Temp storage */
+	__be16 toseq;   	/* Transmit out of sequence char */
+	__be16 cchars[8];       /* control characters 1-8 */
+	__be16 rccm;    	/* receive control character mask */
+	__be16 rccr;    	/* receive control character register */
+	__be16 rlbc;    	/* receive last break character */
+	__be16 res2;    	/* reserved */
+	__be32 res3;    	/* reserved, should be cleared */
+	u8 res4;		/* reserved, should be cleared */
+	u8 res5[3];     	/* reserved, should be cleared */
+	__be32 res6;    	/* reserved, should be cleared */
+	__be32 res7;    	/* reserved, should be cleared */
+	__be32 res8;    	/* reserved, should be cleared */
+	__be32 res9;    	/* reserved, should be cleared */
+	__be32 res10;   	/* reserved, should be cleared */
+	__be32 res11;   	/* reserved, should be cleared */
+	__be32 res12;   	/* reserved, should be cleared */
+	__be32 res13;   	/* reserved, should be cleared */
+/* The rest is for Soft-UART only */
+	__be16 supsmr;  	/* 0x90, Shadow UPSMR */
+	__be16 res92;   	/* 0x92, reserved, initialize to 0 */
+	__be32 rx_state;	/* 0x94, RX state, initialize to 0 */
+	__be32 rx_cnt;  	/* 0x98, RX count, initialize to 0 */
+	u8 rx_length;   	/* 0x9C, Char length, set to 1+CL+PEN+1+SL */
+	u8 rx_bitmark;  	/* 0x9D, reserved, initialize to 0 */
+	u8 rx_temp_dlst_qe;     /* 0x9E, reserved, initialize to 0 */
+	u8 res14[0xBC - 0x9F];  /* reserved */
+	__be32 dump_ptr;	/* 0xBC, Dump pointer */
+	__be32 rx_frame_rem;    /* 0xC0, reserved, initialize to 0 */
+	u8 rx_frame_rem_size;   /* 0xC4, reserved, initialize to 0 */
+	u8 tx_mode;     	/* 0xC5, mode, 0=AHDLC, 1=UART */
+	__be16 tx_state;	/* 0xC6, TX state */
+	u8 res15[0xD0 - 0xC8];  /* reserved */
+	__be32 resD0;   	/* 0xD0, reserved, initialize to 0 */
+	u8 resD4;       	/* 0xD4, reserved, initialize to 0 */
+	__be16 resD5;   	/* 0xD5, reserved, initialize to 0 */
+} __attribute__ ((packed));
+
+/* SUPSMR definitions, for Soft-UART only */
+#define UCC_UART_SUPSMR_SL      	0x8000
+#define UCC_UART_SUPSMR_RPM_MASK	0x6000
+#define UCC_UART_SUPSMR_RPM_ODD 	0x0000
+#define UCC_UART_SUPSMR_RPM_LOW 	0x2000
+#define UCC_UART_SUPSMR_RPM_EVEN	0x4000
+#define UCC_UART_SUPSMR_RPM_HIGH	0x6000
+#define UCC_UART_SUPSMR_PEN     	0x1000
+#define UCC_UART_SUPSMR_TPM_MASK	0x0C00
+#define UCC_UART_SUPSMR_TPM_ODD 	0x0000
+#define UCC_UART_SUPSMR_TPM_LOW 	0x0400
+#define UCC_UART_SUPSMR_TPM_EVEN	0x0800
+#define UCC_UART_SUPSMR_TPM_HIGH	0x0C00
+#define UCC_UART_SUPSMR_FRZ     	0x0100
+#define UCC_UART_SUPSMR_UM_MASK 	0x00c0
+#define UCC_UART_SUPSMR_UM_NORMAL       0x0000
+#define UCC_UART_SUPSMR_UM_MAN_MULTI    0x0040
+#define UCC_UART_SUPSMR_UM_AUTO_MULTI   0x00c0
+#define UCC_UART_SUPSMR_CL_MASK 	0x0030
+#define UCC_UART_SUPSMR_CL_8    	0x0030
+#define UCC_UART_SUPSMR_CL_7    	0x0020
+#define UCC_UART_SUPSMR_CL_6    	0x0010
+#define UCC_UART_SUPSMR_CL_5    	0x0000
+
+#define UCC_UART_TX_STATE_AHDLC 	0x00
+#define UCC_UART_TX_STATE_UART  	0x01
+#define UCC_UART_TX_STATE_X1    	0x00
+#define UCC_UART_TX_STATE_X16   	0x80
+
+#define UCC_UART_PRAM_ALIGNMENT 0x100
+
+#define UCC_UART_SIZE_OF_BD     UCC_SLOW_SIZE_OF_BD
+#define NUM_CONTROL_CHARS       8
+
+/* Private per-port data structure */
+struct uart_qe_port {
+	struct uart_port port;
+	struct ucc_slow __iomem *uccp;
+	struct ucc_uart_pram __iomem *uccup;
+	struct ucc_slow_info us_info;
+	struct ucc_slow_private *us_private;
+	struct device_node *np;
+	unsigned int ucc_num;   /* First ucc is 0, not 1 */
+
+	u16 rx_nrfifos;
+	u16 rx_fifosize;
+	u16 tx_nrfifos;
+	u16 tx_fifosize;
+	int wait_closing;
+	u32 flags;
+	struct qe_bd *rx_bd_base;
+	struct qe_bd *rx_cur;
+	struct qe_bd *tx_bd_base;
+	struct qe_bd *tx_cur;
+	unsigned char *tx_buf;
+	unsigned char *rx_buf;
+	void *bd_virt;  	/* virtual address of the BD buffers */
+	dma_addr_t bd_dma_addr; /* bus address of the BD buffers */
+	unsigned int bd_size;   /* size of BD buffer space */
+};
+
+static struct uart_driver ucc_uart_driver = {
+	.owner  	= THIS_MODULE,
+	.driver_name    = "serial",
+	.dev_name       = "ttyQE",
+	.major  	= SERIAL_QE_MAJOR,
+	.minor  	= SERIAL_QE_MINOR,
+	.nr     	= UCC_MAX_UART,
+};
+
+/*
+ * Virtual to physical address translation.
+ *
+ * Given the virtual address for a character buffer, this function returns
+ * the physical (DMA) equivalent.
+ */
+static inline dma_addr_t cpu2qe_addr(void *addr, struct uart_qe_port *qe_port)
+{
+	if (likely((addr >= qe_port->bd_virt)) &&
+	    (addr < (qe_port->bd_virt + qe_port->bd_size)))
+		return qe_port->bd_dma_addr + (addr - qe_port->bd_virt);
+
+	/* something nasty happened */
+	printk(KERN_ERR "%s: addr=%p\n", __FUNCTION__, addr);
+	BUG();
+	return 0;
+}
+
+/*
+ * Physical to virtual address translation.
+ *
+ * Given the physical (DMA) address for a character buffer, this function
+ * returns the virtual equivalent.
+ */
+static inline void *qe2cpu_addr(dma_addr_t addr, struct uart_qe_port *qe_port)
+{
+	/* sanity check */
+	if (likely((addr >= qe_port->bd_dma_addr) &&
+		   (addr < (qe_port->bd_dma_addr + qe_port->bd_size))))
+		return qe_port->bd_virt + (addr - qe_port->bd_dma_addr);
+
+	/* something nasty happened */
+	printk(KERN_ERR "%s: addr=%x\n", __FUNCTION__, addr);
+	BUG();
+	return NULL;
+}
+
+/*
+ * Return 1 if the QE is done transmitting all buffers for this port
+ *
+ * This function scans each BD in sequence.  If we find a BD that is not
+ * ready (READY=1), then we return 0 indicating that the QE is still sending
+ * data.  If we reach the last BD (WRAP=1), then we know we've scanned
+ * the entire list, and all BDs are done.
+ */
+static unsigned int qe_uart_tx_empty(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	struct qe_bd *bdp = qe_port->tx_bd_base;
+
+	while (1) {
+		if (in_be16(&bdp->status) & BD_SC_READY)
+			/* This BD is not done, so return "not done" */
+			return 0;
+
+		if (in_be16(&bdp->status) & BD_SC_WRAP)
+			/*
+			 * This BD is done and it's the last one, so return
+			 * "done"
+			 */
+			return 1;
+
+		bdp++;
+	};
+}
+
+/*
+ * Set the modem control lines
+ *
+ * Although the QE can control the modem control lines (e.g. CTS), we
+ * don't need that support. This function must exist, however, otherwise
+ * the kernel will panic.
+ */
+void qe_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+/*
+ * Get the current modem control line status
+ *
+ * Although the QE can control the modem control lines (e.g. CTS), this
+ * driver currently doesn't support that, so we always return Carrier
+ * Detect, Data Set Ready, and Clear To Send.
+ */
+static unsigned int qe_uart_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+/*
+ * Disable the transmit interrupt.
+ *
+ * Although this function is called "stop_tx", it does not actually stop
+ * transmission of data.  Instead, it tells the QE to not generate an
+ * interrupt when the UCC is finished sending characters.
+ */
+static void qe_uart_stop_tx(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+
+	clrbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_TX);
+}
+
+/*
+ * Transmit as many characters to the HW as possible.
+ *
+ * This function will attempt to stuff of all the characters from the
+ * kernel's transmit buffer into TX BDs.
+ *
+ * A return value of non-zero indicates that it sucessfully stuffed all
+ * characters from the kernel buffer.
+ *
+ * A return value of zero indicates that there are still characters in the
+ * kernel's buffer that have not been transmitted, but there are no more BDs
+ * available.  This function should be called again after a BD has been made
+ * available.
+ */
+static int qe_uart_tx_pump(struct uart_qe_port *qe_port)
+{
+	struct qe_bd *bdp;
+	unsigned char *p;
+	unsigned int count;
+	struct uart_port *port = &qe_port->port;
+	struct circ_buf *xmit = &port->info->xmit;
+
+	bdp = qe_port->rx_cur;
+
+	/* Handle xon/xoff */
+	if (port->x_char) {
+		/* Pick next descriptor and fill from buffer */
+		bdp = qe_port->tx_cur;
+
+		p = qe2cpu_addr(bdp->buf, qe_port);
+
+		*p++ = port->x_char;
+		out_be16(&bdp->length, 1);
+		setbits16(&bdp->status, BD_SC_READY);
+		/* Get next BD. */
+		if (in_be16(&bdp->status) & BD_SC_WRAP)
+			bdp = qe_port->tx_bd_base;
+		else
+			bdp++;
+		qe_port->tx_cur = bdp;
+
+		port->icount.tx++;
+		port->x_char = 0;
+		return 1;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		qe_uart_stop_tx(port);
+		return 0;
+	}
+
+	/* Pick next descriptor and fill from buffer */
+	bdp = qe_port->tx_cur;
+
+	while (!(in_be16(&bdp->status) & BD_SC_READY) &&
+	       (xmit->tail != xmit->head)) {
+		count = 0;
+		p = qe2cpu_addr(bdp->buf, qe_port);
+		while (count < qe_port->tx_fifosize) {
+			*p++ = xmit->buf[xmit->tail];
+			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+			port->icount.tx++;
+			count++;
+			if (xmit->head == xmit->tail)
+				break;
+		}
+
+		out_be16(&bdp->length, count);
+		setbits16(&bdp->status, BD_SC_READY);
+
+		/* Get next BD. */
+		if (in_be16(&bdp->status) & BD_SC_WRAP)
+			bdp = qe_port->tx_bd_base;
+		else
+			bdp++;
+	}
+	qe_port->tx_cur = bdp;
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit)) {
+		/* The kernel buffer is empty, so turn off TX interrupts.  We
+		   don't need to be told when the QE is finished transmitting
+		   the data. */
+		qe_uart_stop_tx(port);
+		return 0;
+	}
+
+	return 1;
+}
+
+/*
+ * Start transmitting data
+ *
+ * This function will start transmitting any available data, if the port
+ * isn't already transmitting data.
+ */
+static void qe_uart_start_tx(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+
+	/* If we currently are transmitting, then just return */
+	if (in_be16(&qe_port->uccp->uccm) & UCC_UART_UCCE_TX)
+		return;
+
+	/* Otherwise, pump the port and start transmission */
+	if (qe_uart_tx_pump(qe_port))
+		setbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_TX);
+}
+
+/*
+ * Stop transmitting data
+ */
+static void qe_uart_stop_rx(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+
+	clrbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_RX);
+}
+
+/*
+ * Enable status change interrupts
+ *
+ * We don't support status change interrupts, but we need to define this
+ * function otherwise the kernel will panic.
+ */
+static void qe_uart_enable_ms(struct uart_port *port)
+{
+}
+
+/* Start or stop sending  break signal
+ *
+ * This function controls the sending of a break signal.  If break_state=1,
+ * then we start sending a break signal.  If break_state=0, then we stop
+ * sending the break signal.
+ */
+static void qe_uart_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+
+	if (break_state)
+		ucc_slow_stop_tx(qe_port->us_private);
+	else
+		ucc_slow_restart_tx(qe_port->us_private);
+}
+
+/* ISR helper function for receiving character.
+ *
+ * This function is called by the ISR to handling receiving characters
+ */
+static void qe_uart_int_rx(struct uart_qe_port *qe_port)
+{
+	int i;
+	unsigned char ch, *cp;
+	struct uart_port *port = &qe_port->port;
+	struct tty_struct *tty = port->info->tty;
+	struct qe_bd *bdp;
+	u16 status;
+	unsigned int flg;
+
+	/* Just loop through the closed BDs and copy the characters into
+	 * the buffer.
+	 */
+	bdp = qe_port->rx_cur;
+	while (1) {
+		status = in_be16(&bdp->status);
+
+		/* If this one is empty, then we assume we've read them all */
+		if (status & BD_SC_EMPTY)
+			break;
+
+		/* get number of characters, and check space in RX buffer */
+		i = in_be16(&bdp->length);
+
+		/* If we don't have enough room in RX buffer for the entire BD,
+		 * then we try later, which will be the next RX interrupt.
+		 */
+		if (tty_buffer_request_room(tty, i) < i) {
+			dev_dbg(port->dev, "ucc-uart: no room in RX buffer\n");
+			return;
+		}
+
+		/* get pointer */
+		cp = qe2cpu_addr(bdp->buf, qe_port);
+
+		/* loop through the buffer */
+		while (i-- > 0) {
+			ch = *cp++;
+			port->icount.rx++;
+			flg = TTY_NORMAL;
+
+			if (!i && status &
+			    (BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV))
+				goto handle_error;
+			if (uart_handle_sysrq_char(port, ch))
+				continue;
+
+error_return:
+			tty_insert_flip_char(tty, ch, flg);
+
+		}
+
+		/* This BD is ready to be used again. Clear status. get next */
+		clrsetbits_be16(&bdp->status, BD_SC_BR | BD_SC_FR | BD_SC_PR |
+			BD_SC_OV | BD_SC_ID, BD_SC_EMPTY);
+		if (in_be16(&bdp->status) & BD_SC_WRAP)
+			bdp = qe_port->rx_bd_base;
+		else
+			bdp++;
+
+	}
+
+	/* Write back buffer pointer */
+	qe_port->rx_cur = bdp;
+
+	/* Activate BH processing */
+	tty_flip_buffer_push(tty);
+
+	return;
+
+	/* Error processing */
+
+handle_error:
+	/* Statistics */
+	if (status & BD_SC_BR)
+		port->icount.brk++;
+	if (status & BD_SC_PR)
+		port->icount.parity++;
+	if (status & BD_SC_FR)
+		port->icount.frame++;
+	if (status & BD_SC_OV)
+		port->icount.overrun++;
+
+	/* Mask out ignored conditions */
+	status &= port->read_status_mask;
+
+	/* Handle the remaining ones */
+	if (status & BD_SC_BR)
+		flg = TTY_BREAK;
+	else if (status & BD_SC_PR)
+		flg = TTY_PARITY;
+	else if (status & BD_SC_FR)
+		flg = TTY_FRAME;
+
+	/* Overrun does not affect the current character ! */
+	if (status & BD_SC_OV)
+		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+#ifdef SUPPORT_SYSRQ
+	port->sysrq = 0;
+#endif
+	goto error_return;
+}
+
+/* Interrupt handler
+ *
+ * This interrupt handler is called after a BD is processed.
+ */
+static irqreturn_t qe_uart_int(int irq, void *data)
+{
+	struct uart_qe_port *qe_port = (struct uart_qe_port *) data;
+	struct ucc_slow __iomem *uccp = qe_port->uccp;
+	u16 events;
+
+	/* Clear the interrupts */
+	events = in_be16(&uccp->ucce);
+	out_be16(&uccp->ucce, events);
+
+	if (events & UCC_UART_UCCE_BRKE)
+		uart_handle_break(&qe_port->port);
+
+	if (events & UCC_UART_UCCE_RX)
+		qe_uart_int_rx(qe_port);
+
+	if (events & UCC_UART_UCCE_TX)
+		qe_uart_tx_pump(qe_port);
+
+	return events ? IRQ_HANDLED : IRQ_NONE;
+}
+
+/* Initialize buffer descriptors
+ *
+ * This function initializes all of the RX and TX buffer descriptors.
+ */
+static void qe_uart_initbd(struct uart_qe_port *qe_port)
+{
+	int i;
+	void *bd_virt;
+	struct qe_bd *bdp;
+
+	/* Set the physical address of the host memory buffers in the buffer
+	 * descriptors, and the virtual address for us to work with.
+	 */
+	bd_virt = qe_port->bd_virt;
+	bdp = qe_port->rx_bd_base;
+	qe_port->rx_cur = qe_port->rx_bd_base;
+	for (i = 0; i < (qe_port->rx_nrfifos - 1); i++) {
+		out_be16(&bdp->status, BD_SC_EMPTY | BD_SC_INTRPT);
+		out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port));
+		out_be16(&bdp->length, 0);
+		bd_virt += qe_port->rx_fifosize;
+		bdp++;
+	}
+
+	/* */
+	out_be16(&bdp->status, BD_SC_WRAP | BD_SC_EMPTY | BD_SC_INTRPT);
+	out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port));
+	out_be16(&bdp->length, 0);
+
+	/* Set the physical address of the host memory
+	 * buffers in the buffer descriptors, and the
+	 * virtual address for us to work with.
+	 */
+	bd_virt = qe_port->bd_virt +
+		L1_CACHE_ALIGN(qe_port->rx_nrfifos * qe_port->rx_fifosize);
+	qe_port->tx_cur = qe_port->tx_bd_base;
+	bdp = qe_port->tx_bd_base;
+	for (i = 0; i < (qe_port->tx_nrfifos - 1); i++) {
+		out_be16(&bdp->status, BD_SC_INTRPT);
+		out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port));
+		out_be16(&bdp->length, 0);
+		bd_virt += qe_port->tx_fifosize;
+		bdp++;
+	}
+
+	/* Loopback requires the preamble bit to be set on the first TX BD */
+#ifdef LOOPBACK
+	setbits16(&qe_port->tx_cur->status, BD_SC_P);
+#endif
+
+	out_be16(&bdp->status, BD_SC_WRAP | BD_SC_INTRPT);
+	out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port));
+	out_be16(&bdp->length, 0);
+}
+
+/*
+ * Initialize a UCC for UART.
+ *
+ * This function configures a given UCC to be used as a UART device. Basic
+ * UCC initialization is handled in qe_uart_request_port().  This function
+ * does all the UART-specific stuff.
+ */
+static void qe_uart_init_ucc(struct uart_qe_port *qe_port)
+{
+	u32 cecr_subblock;
+	struct ucc_slow __iomem *uccp = qe_port->uccp;
+	struct ucc_uart_pram *uccup = qe_port->uccup;
+
+	unsigned int i;
+
+	/* First, disable TX and RX in the UCC */
+	ucc_slow_disable(qe_port->us_private, COMM_DIR_RX_AND_TX);
+
+	/* Program the UCC UART parameter RAM */
+	out_8(&uccup->common.rbmr, UCC_BMR_GBL | UCC_BMR_BO_BE);
+	out_8(&uccup->common.tbmr, UCC_BMR_GBL | UCC_BMR_BO_BE);
+	out_be16(&uccup->common.mrblr, qe_port->rx_fifosize);
+	out_be16(&uccup->maxidl, 0x10);
+	out_be16(&uccup->brkcr, 1);
+	out_be16(&uccup->parec, 0);
+	out_be16(&uccup->frmec, 0);
+	out_be16(&uccup->nosec, 0);
+	out_be16(&uccup->brkec, 0);
+	out_be16(&uccup->uaddr[0], 0);
+	out_be16(&uccup->uaddr[1], 0);
+	out_be16(&uccup->toseq, 0);
+	for (i = 0; i < 8; i++)
+		out_be16(&uccup->cchars[i], 0xC000);
+	out_be16(&uccup->rccm, 0xc0ff);
+
+	/* Configure the GUMR registers for UART */
+	if (soft_uart)
+		/* Soft-UART requires a 1X multiplier for TX */
+		clrsetbits_be32(&uccp->gumr_l,
+			UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK |
+			UCC_SLOW_GUMR_L_RDCR_MASK,
+			UCC_SLOW_GUMR_L_MODE_UART | UCC_SLOW_GUMR_L_TDCR_1 |
+			UCC_SLOW_GUMR_L_RDCR_16);
+	else
+		clrsetbits_be32(&uccp->gumr_l,
+			UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK |
+			UCC_SLOW_GUMR_L_RDCR_MASK,
+			UCC_SLOW_GUMR_L_MODE_UART | UCC_SLOW_GUMR_L_TDCR_16 |
+			UCC_SLOW_GUMR_L_RDCR_16);
+
+	clrsetbits_be32(&uccp->gumr_h, UCC_SLOW_GUMR_H_RFW,
+		UCC_SLOW_GUMR_H_TRX | UCC_SLOW_GUMR_H_TTX);
+
+#ifdef LOOPBACK
+	clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_DIAG_MASK,
+		UCC_SLOW_GUMR_L_DIAG_LOOP);
+	clrsetbits_be32(&uccp->gumr_h,
+		UCC_SLOW_GUMR_H_CTSP | UCC_SLOW_GUMR_H_RSYN,
+		UCC_SLOW_GUMR_H_CDS);
+#endif
+
+	/* Enable rx interrupts  and clear all pending events.  */
+	out_be16(&uccp->uccm, 0);
+	out_be16(&uccp->ucce, 0xffff);
+	out_be16(&uccp->udsr, 0x7e7e);
+
+	/* Initialize UPSMR */
+	out_be16(&uccp->upsmr, 0);
+
+	if (soft_uart) {
+		out_be16(&uccup->supsmr, 0x30);
+		out_be16(&uccup->res92, 0);
+		out_be32(&uccup->rx_state, 0);
+		out_be32(&uccup->rx_cnt, 0);
+		out_8(&uccup->rx_bitmark, 0);
+		out_8(&uccup->rx_length, 10);
+		out_be32(&uccup->dump_ptr, 0x4000);
+		out_8(&uccup->rx_temp_dlst_qe, 0);
+		out_be32(&uccup->rx_frame_rem, 0);
+		out_8(&uccup->rx_frame_rem_size, 0);
+		/* Soft-UART requires TX to be 1X */
+		out_8(&uccup->tx_mode,
+			UCC_UART_TX_STATE_UART | UCC_UART_TX_STATE_X1);
+		out_be16(&uccup->tx_state, 0);
+		out_8(&uccup->resD4, 0);
+		out_be16(&uccup->resD5, 0);
+
+		/* Set UART mode.
+		 * Enable receive and transmit.
+		 */
+
+		/* From the microcode errata:
+		 * 1.GUMR_L register, set mode=0010 (QMC).
+		 * 2.Set GUMR_H[17] bit. (UART/AHDLC mode).
+		 * 3.Set GUMR_H[19:20] (Transparent mode)
+		 * 4.Clear GUMR_H[26] (RFW)
+		 * ...
+		 * 6.Receiver must use 16x over sampling
+		 */
+		clrsetbits_be32(&uccp->gumr_l,
+			UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK |
+			UCC_SLOW_GUMR_L_RDCR_MASK,
+			UCC_SLOW_GUMR_L_MODE_QMC | UCC_SLOW_GUMR_L_TDCR_16 |
+			UCC_SLOW_GUMR_L_RDCR_16);
+
+		clrsetbits_be32(&uccp->gumr_h,
+			UCC_SLOW_GUMR_H_RFW | UCC_SLOW_GUMR_H_RSYN,
+			UCC_SLOW_GUMR_H_SUART | UCC_SLOW_GUMR_H_TRX |
+			UCC_SLOW_GUMR_H_TTX | UCC_SLOW_GUMR_H_TFL);
+
+#ifdef LOOPBACK
+		clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_DIAG_MASK,
+				UCC_SLOW_GUMR_L_DIAG_LOOP);
+		clrbits32(&uccp->gumr_h, UCC_SLOW_GUMR_H_CTSP |
+			  UCC_SLOW_GUMR_H_CDS);
+#endif
+
+		cecr_subblock = ucc_slow_get_qe_cr_subblock(qe_port->ucc_num);
+		qe_issue_cmd(QE_INIT_TX_RX, cecr_subblock,
+			QE_CR_PROTOCOL_UNSPECIFIED, 0);
+	}
+}
+
+/*
+ * Initialize the port.
+ */
+static int qe_uart_startup(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	int ret;
+
+	/*
+	 * If we're using Soft-UART mode, then we need to make sure the
+	 * firmware has been uploaded first.
+	 */
+	if (soft_uart && !firmware_loaded) {
+		dev_err(port->dev, "Soft-UART firmware not uploaded\n");
+		return -ENODEV;
+	}
+
+	qe_uart_initbd(qe_port);
+	qe_uart_init_ucc(qe_port);
+
+	/* Install interrupt handler. */
+	ret = request_irq(port->irq, qe_uart_int, IRQF_SHARED, "ucc-uart",
+		qe_port);
+	if (ret) {
+		dev_err(port->dev, "could not claim IRQ %u\n", port->irq);
+		return ret;
+	}
+
+	/* Startup rx-int */
+	setbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_RX);
+	ucc_slow_enable(qe_port->us_private, COMM_DIR_RX_AND_TX);
+
+	return 0;
+}
+
+/*
+ * Shutdown the port.
+ */
+static void qe_uart_shutdown(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	struct ucc_slow __iomem *uccp = qe_port->uccp;
+	unsigned int timeout = 20;
+
+	/* Disable RX and TX */
+
+	/* Wait for all the BDs marked sent */
+	while (!qe_uart_tx_empty(port)) {
+		if (!--timeout) {
+			dev_warn(port->dev, "shutdown timeout\n");
+			break;
+		}
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule_timeout(2);
+	}
+
+	if (qe_port->wait_closing) {
+		/* Wait a bit longer */
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule_timeout(qe_port->wait_closing);
+	}
+
+	/* Stop uarts */
+	ucc_slow_disable(qe_port->us_private, COMM_DIR_RX_AND_TX);
+	clrbits16(&uccp->uccm, UCC_UART_UCCE_TX | UCC_UART_UCCE_RX);
+
+	/* Shut them really down and reinit buffer descriptors */
+	ucc_slow_graceful_stop_tx(qe_port->us_private);
+	qe_uart_initbd(qe_port);
+
+	free_irq(port->irq, qe_port);
+}
+
+/*
+ * Set the serial port parameters.
+ */
+static void qe_uart_set_termios(struct uart_port *port,
+				struct ktermios *termios, struct ktermios *old)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	struct ucc_slow __iomem *uccp = qe_port->uccp;
+	unsigned int baud;
+	unsigned long flags;
+	u16 upsmr = in_be16(&uccp->upsmr);
+	struct ucc_uart_pram __iomem *uccup = qe_port->uccup;
+	u16 supsmr = in_be16(&uccup->supsmr);
+	u8 char_length = 2; /* 1 + CL + PEN + 1 + SL */
+
+	/* Character length programmed into the mode register is the
+	 * sum of: 1 start bit, number of data bits, 0 or 1 parity bit,
+	 * 1 or 2 stop bits, minus 1.
+	 * The value 'bits' counts this for us.
+	 */
+
+	/* byte size */
+	upsmr &= UCC_UART_UPSMR_CL_MASK;
+	supsmr &= UCC_UART_SUPSMR_CL_MASK;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		upsmr |= UCC_UART_UPSMR_CL_5;
+		supsmr |= UCC_UART_SUPSMR_CL_5;
+		char_length += 5;
+		break;
+	case CS6:
+		upsmr |= UCC_UART_UPSMR_CL_6;
+		supsmr |= UCC_UART_SUPSMR_CL_6;
+		char_length += 6;
+		break;
+	case CS7:
+		upsmr |= UCC_UART_UPSMR_CL_7;
+		supsmr |= UCC_UART_SUPSMR_CL_7;
+		char_length += 7;
+		break;
+	default:	/* case CS8 */
+		upsmr |= UCC_UART_UPSMR_CL_8;
+		supsmr |= UCC_UART_SUPSMR_CL_8;
+		char_length += 8;
+		break;
+	}
+
+	/* If CSTOPB is set, we want two stop bits */
+	if (termios->c_cflag & CSTOPB) {
+		upsmr |= UCC_UART_UPSMR_SL;
+		supsmr |= UCC_UART_SUPSMR_SL;
+		char_length++;  /* + SL */
+	}
+
+	if (termios->c_cflag & PARENB) {
+		upsmr |= UCC_UART_UPSMR_PEN;
+		supsmr |= UCC_UART_SUPSMR_PEN;
+		char_length++;  /* + PEN */
+
+		if (!(termios->c_cflag & PARODD)) {
+			upsmr &= ~(UCC_UART_UPSMR_RPM_MASK |
+				   UCC_UART_UPSMR_TPM_MASK);
+			upsmr |= UCC_UART_UPSMR_RPM_EVEN |
+				UCC_UART_UPSMR_TPM_EVEN;
+			supsmr &= ~(UCC_UART_SUPSMR_RPM_MASK |
+				    UCC_UART_SUPSMR_TPM_MASK);
+			supsmr |= UCC_UART_SUPSMR_RPM_EVEN |
+				UCC_UART_SUPSMR_TPM_EVEN;
+		}
+	}
+
+	/*
+	 * Set up parity check flag
+	 */
+	port->read_status_mask = BD_SC_EMPTY | BD_SC_OV;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= BD_SC_FR | BD_SC_PR;
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		port->read_status_mask |= BD_SC_BR;
+
+	/*
+	 * Characters to ignore
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= BD_SC_PR | BD_SC_FR;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= BD_SC_BR;
+		/*
+		 * If we're ignore parity and break indicators, ignore
+		 * overruns too.  (For real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= BD_SC_OV;
+	}
+	/*
+	 * !!! ignore all characters if CREAD is not set
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->read_status_mask &= ~BD_SC_EMPTY;
+
+	baud = uart_get_baud_rate(port, termios, old, 0, 115200);
+
+	/* Do we really need a spinlock here? */
+	spin_lock_irqsave(&port->lock, flags);
+
+	out_be16(&uccp->upsmr, upsmr);
+	if (soft_uart) {
+		out_be16(&uccup->supsmr, supsmr);
+		out_8(&uccup->rx_length, char_length);
+
+		/* Soft-UART requires a 1X multiplier for TX */
+		qe_setbrg(qe_port->us_info.rx_clock, baud, 16);
+		qe_setbrg(qe_port->us_info.tx_clock, baud, 1);
+	} else {
+		qe_setbrg(qe_port->us_info.rx_clock, baud, 16);
+		qe_setbrg(qe_port->us_info.tx_clock, baud, 16);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/*
+ * Return a pointer to a string that describes what kind of port this is.
+ */
+static const char *qe_uart_type(struct uart_port *port)
+{
+	return "QE";
+}
+
+/*
+ * Allocate any memory and I/O resources required by the port.
+ */
+static int qe_uart_request_port(struct uart_port *port)
+{
+	int ret;
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	struct ucc_slow_info *us_info = &qe_port->us_info;
+	struct ucc_slow_private *uccs;
+	unsigned int rx_size, tx_size;
+	void *bd_virt;
+	dma_addr_t bd_dma_addr = 0;
+
+	ret = ucc_slow_init(us_info, &uccs);
+	if (ret) {
+		dev_err(port->dev, "could not initialize UCC%u\n",
+		       qe_port->ucc_num);
+		return ret;
+	}
+
+	qe_port->us_private = uccs;
+	qe_port->uccp = uccs->us_regs;
+	qe_port->uccup = (struct ucc_uart_pram *) uccs->us_pram;
+	qe_port->rx_bd_base = uccs->rx_bd;
+	qe_port->tx_bd_base = uccs->tx_bd;
+
+	/*
+	 * Allocate the transmit and receive data buffers.
+	 */
+
+	rx_size = L1_CACHE_ALIGN(qe_port->rx_nrfifos * qe_port->rx_fifosize);
+	tx_size = L1_CACHE_ALIGN(qe_port->tx_nrfifos * qe_port->tx_fifosize);
+
+	bd_virt = dma_alloc_coherent(NULL, rx_size + tx_size, &bd_dma_addr,
+		GFP_KERNEL);
+	if (!bd_virt) {
+		dev_err(port->dev, "could not allocate buffer descriptors\n");
+		return -ENOMEM;
+	}
+
+	qe_port->bd_virt = bd_virt;
+	qe_port->bd_dma_addr = bd_dma_addr;
+	qe_port->bd_size = rx_size + tx_size;
+
+	qe_port->rx_buf = bd_virt;
+	qe_port->tx_buf = qe_port->rx_buf + rx_size;
+
+	return 0;
+}
+
+/*
+ * Configure the port.
+ *
+ * We say we're a CPM-type port because that's mostly true.  Once the device
+ * is configured, this driver operates almost identically to the CPM serial
+ * driver.
+ */
+static void qe_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_CPM;
+		qe_uart_request_port(port);
+	}
+}
+
+/*
+ * Release any memory and I/O resources that were allocated in
+ * qe_uart_request_port().
+ */
+static void qe_uart_release_port(struct uart_port *port)
+{
+	struct uart_qe_port *qe_port =
+		container_of(port, struct uart_qe_port, port);
+	struct ucc_slow_private *uccs = qe_port->us_private;
+
+	dma_free_coherent(NULL, qe_port->bd_size, qe_port->bd_virt,
+			  qe_port->bd_dma_addr);
+
+	ucc_slow_free(uccs);
+}
+
+/*
+ * Verify that the data in serial_struct is suitable for this device.
+ */
+static int qe_uart_verify_port(struct uart_port *port,
+			       struct serial_struct *ser)
+{
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_CPM)
+		return -EINVAL;
+
+	if (ser->irq < 0 || ser->irq >= NR_IRQS)
+		return -EINVAL;
+
+	if (ser->baud_base < 9600)
+		return -EINVAL;
+
+	return 0;
+}
+/* UART operations
+ *
+ * Details on these functions can be found in Documentation/serial/driver
+ */
+static struct uart_ops qe_uart_pops = {
+	.tx_empty       = qe_uart_tx_empty,
+	.set_mctrl      = qe_uart_set_mctrl,
+	.get_mctrl      = qe_uart_get_mctrl,
+	.stop_tx	= qe_uart_stop_tx,
+	.start_tx       = qe_uart_start_tx,
+	.stop_rx	= qe_uart_stop_rx,
+	.enable_ms      = qe_uart_enable_ms,
+	.break_ctl      = qe_uart_break_ctl,
+	.startup	= qe_uart_startup,
+	.shutdown       = qe_uart_shutdown,
+	.set_termios    = qe_uart_set_termios,
+	.type   	= qe_uart_type,
+	.release_port   = qe_uart_release_port,
+	.request_port   = qe_uart_request_port,
+	.config_port    = qe_uart_config_port,
+	.verify_port    = qe_uart_verify_port,
+};
+
+/*
+ * Obtain the SOC model number and revision level
+ *
+ * This function parses the device tree to obtain the SOC model.  It then
+ * reads the SVR register to the revision.
+ *
+ * The device tree stores the SOC model two different ways.
+ *
+ * The new way is:
+ *
+ *      	cpu@0 {
+ *      		compatible = "PowerPC,8323";
+ *      		device_type = "cpu";
+ *      		...
+ *
+ *
+ * The old way is:
+ *      	 PowerPC,8323@0 {
+ *      		device_type = "cpu";
+ *      		...
+ *
+ * This code first checks the new way, and then the old way.
+ */
+static unsigned int soc_info(unsigned int *rev_h, unsigned int *rev_l)
+{
+	struct device_node *np;
+	const char *soc_string;
+	unsigned int svr;
+	unsigned int soc;
+
+	/* Find the CPU node */
+	np = of_find_node_by_type(NULL, "cpu");
+	if (!np)
+		return 0;
+	/* Find the compatible property */
+	soc_string = of_get_property(np, "compatible", NULL);
+	if (!soc_string)
+		/* No compatible property, so try the name. */
+		soc_string = np->name;
+
+	/* Extract the SOC number from the "PowerPC," string */
+	if ((sscanf(soc_string, "PowerPC,%u", &soc) != 1) || !soc)
+		return 0;
+
+	/* Get the revision from the SVR */
+	svr = mfspr(SPRN_SVR);
+	*rev_h = (svr >> 4) & 0xf;
+	*rev_l = svr & 0xf;
+
+	return soc;
+}
+
+/*
+ * requst_firmware_nowait() callback function
+ *
+ * This function is called by the kernel when a firmware is made available,
+ * or if it times out waiting for the firmware.
+ */
+static void uart_firmware_cont(const struct firmware *fw, void *context)
+{
+	struct qe_firmware *firmware;
+	struct device *dev = context;
+	int ret;
+
+	if (!fw) {
+		dev_err(dev, "firmware not found\n");
+		return;
+	}
+
+	firmware = (struct qe_firmware *) fw->data;
+
+	if (firmware->header.length != fw->size) {
+		dev_err(dev, "invalid firmware\n");
+		return;
+	}
+
+	ret = qe_upload_firmware(firmware);
+	if (ret) {
+		dev_err(dev, "could not load firmware\n");
+		return;
+	}
+
+	firmware_loaded = 1;
+}
+
+static int ucc_uart_probe(struct of_device *ofdev,
+	const struct of_device_id *match)
+{
+	struct device_node *np = ofdev->node;
+	const unsigned int *iprop;      /* Integer OF properties */
+	const char *sprop;      /* String OF properties */
+	struct uart_qe_port *qe_port = NULL;
+	struct resource res;
+	int ret;
+
+	/*
+	 * Determine if we need Soft-UART mode
+	 */
+	if (of_find_property(np, "soft-uart", NULL)) {
+		dev_dbg(&ofdev->dev, "using Soft-UART mode\n");
+		soft_uart = 1;
+	}
+
+	/*
+	 * If we are using Soft-UART, determine if we need to upload the
+	 * firmware, too.
+	 */
+	if (soft_uart) {
+		struct qe_firmware_info *qe_fw_info;
+
+		qe_fw_info = qe_get_firmware_info();
+
+		/* Check if the firmware has been uploaded. */
+		if (qe_fw_info && strstr(qe_fw_info->id, "Soft-UART")) {
+			firmware_loaded = 1;
+		} else {
+			char filename[32];
+			unsigned int soc;
+			unsigned int rev_h;
+			unsigned int rev_l;
+
+			soc = soc_info(&rev_h, &rev_l);
+			if (!soc) {
+				dev_err(&ofdev->dev, "unknown CPU model\n");
+				return -ENXIO;
+			}
+			sprintf(filename, "fsl_qe_ucode_uart_%u_%u%u.bin",
+				soc, rev_h, rev_l);
+
+			dev_info(&ofdev->dev, "waiting for firmware %s\n",
+				filename);
+
+			/*
+			 * We call request_firmware_nowait instead of
+			 * request_firmware so that the driver can load and
+			 * initialize the ports without holding up the rest of
+			 * the kernel.  If hotplug support is enabled in the
+			 * kernel, then we use it.
+			 */
+			ret = request_firmware_nowait(THIS_MODULE,
+				FW_ACTION_HOTPLUG, filename, &ofdev->dev,
+				&ofdev->dev, uart_firmware_cont);
+			if (ret) {
+				dev_err(&ofdev->dev,
+					"could not load firmware %s\n",
+					filename);
+				return ret;
+			}
+		}
+	}
+
+	qe_port = kzalloc(sizeof(struct uart_qe_port), GFP_KERNEL);
+	if (!qe_port) {
+		dev_err(&ofdev->dev, "can't allocate QE port structure\n");
+		return -ENOMEM;
+	}
+
+	/* Search for IRQ and mapbase */
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret) {
+		dev_err(&ofdev->dev, "missing 'reg' property in device tree\n");
+		kfree(qe_port);
+		return ret;
+	}
+	if (!res.start) {
+		dev_err(&ofdev->dev, "invalid 'reg' property in device tree\n");
+		kfree(qe_port);
+		return -EINVAL;
+	}
+	qe_port->port.mapbase = res.start;
+
+	/* Get the UCC number (device ID) */
+	/* UCCs are numbered 1-7 */
+	iprop = of_get_property(np, "device-id", NULL);
+	if (!iprop || (*iprop < 1) || (*iprop > UCC_MAX_NUM)) {
+		dev_err(&ofdev->dev,
+			"missing or invalid UCC specified in device tree\n");
+		kfree(qe_port);
+		return -ENODEV;
+	}
+	qe_port->ucc_num = *iprop - 1;
+
+	/*
+	 * In the future, we should not require the BRG to be specified in the
+	 * device tree.  If no clock-source is specified, then just pick a BRG
+	 * to use.  This requires a new QE library function that manages BRG
+	 * assignments.
+	 */
+
+	sprop = of_get_property(np, "rx-clock-name", NULL);
+	if (!sprop) {
+		dev_err(&ofdev->dev, "missing rx-clock-name in device tree\n");
+		kfree(qe_port);
+		return -ENODEV;
+	}
+
+	qe_port->us_info.rx_clock = qe_clock_source(sprop);
+	if ((qe_port->us_info.rx_clock < QE_BRG1) ||
+	    (qe_port->us_info.rx_clock > QE_BRG16)) {
+		dev_err(&ofdev->dev, "rx-clock-name must be a BRG for UART\n");
+		kfree(qe_port);
+		return -ENODEV;
+	}
+
+#ifdef LOOPBACK
+	/* In internal loopback mode, TX and RX must use the same clock */
+	qe_port->us_info.tx_clock = qe_port->us_info.rx_clock;
+#else
+	sprop = of_get_property(np, "tx-clock-name", NULL);
+	if (!sprop) {
+		dev_err(&ofdev->dev, "missing tx-clock-name in device tree\n");
+		kfree(qe_port);
+		return -ENODEV;
+	}
+	qe_port->us_info.tx_clock = qe_clock_source(sprop);
+#endif
+	if ((qe_port->us_info.tx_clock < QE_BRG1) ||
+	    (qe_port->us_info.tx_clock > QE_BRG16)) {
+		dev_err(&ofdev->dev, "tx-clock-name must be a BRG for UART\n");
+		kfree(qe_port);
+		return -ENODEV;
+	}
+
+	/* Get the port number, numbered 0-3 */
+	iprop = of_get_property(np, "port-number", NULL);
+	if (!iprop) {
+		dev_err(&ofdev->dev, "missing port-number in device tree\n");
+		kfree(qe_port);
+		return -EINVAL;
+	}
+	qe_port->port.line = *iprop;
+	if (qe_port->port.line >= UCC_MAX_UART) {
+		dev_err(&ofdev->dev, "port-number must be 0-%u\n",
+			UCC_MAX_UART - 1);
+		kfree(qe_port);
+		return -EINVAL;
+	}
+
+	qe_port->port.irq = irq_of_parse_and_map(np, 0);
+	if (qe_port->port.irq == NO_IRQ) {
+		dev_err(&ofdev->dev, "could not map IRQ for UCC%u\n",
+		       qe_port->ucc_num + 1);
+		kfree(qe_port);
+		return -EINVAL;
+	}
+
+	/*
+	 * Newer device trees have an "fsl,qe" compatible property for the QE
+	 * node, but we still need to support older device trees.
+	 */
+	np = of_find_compatible_node(NULL, NULL, "fsl,qe");
+	if (!np) {
+		np = of_find_node_by_type(NULL, "qe");
+		if (!np) {
+			dev_err(&ofdev->dev, "could not find 'qe' node\n");
+			kfree(qe_port);
+			return -EINVAL;
+		}
+	}
+
+	iprop = of_get_property(np, "brg-frequency", NULL);
+	if (!iprop) {
+		dev_err(&ofdev->dev,
+		       "missing brg-frequency in device tree\n");
+		kfree(qe_port);
+		return -EINVAL;
+	}
+
+	if (*iprop)
+		qe_port->port.uartclk = *iprop;
+	else {
+		/*
+		 * Older versions of U-Boot do not initialize the brg-frequency
+		 * property, so in this case we assume the BRG frequency is
+		 * half the QE bus frequency.
+		 */
+		iprop = of_get_property(np, "bus-frequency", NULL);
+		if (!iprop) {
+			dev_err(&ofdev->dev,
+				"missing QE bus-frequency in device tree\n");
+			kfree(qe_port);
+			return -EINVAL;
+		}
+		if (*iprop)
+			qe_port->port.uartclk = *iprop / 2;
+		else {
+			dev_err(&ofdev->dev,
+				"invalid QE bus-frequency in device tree\n");
+			kfree(qe_port);
+			return -EINVAL;
+		}
+	}
+
+	spin_lock_init(&qe_port->port.lock);
+	qe_port->np = np;
+	qe_port->port.dev = &ofdev->dev;
+	qe_port->port.ops = &qe_uart_pops;
+	qe_port->port.iotype = UPIO_MEM;
+
+	qe_port->tx_nrfifos = TX_NUM_FIFO;
+	qe_port->tx_fifosize = TX_BUF_SIZE;
+	qe_port->rx_nrfifos = RX_NUM_FIFO;
+	qe_port->rx_fifosize = RX_BUF_SIZE;
+
+	qe_port->wait_closing = UCC_WAIT_CLOSING;
+	qe_port->port.fifosize = 512;
+	qe_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
+
+	qe_port->us_info.ucc_num = qe_port->ucc_num;
+	qe_port->us_info.regs = (phys_addr_t) res.start;
+	qe_port->us_info.irq = qe_port->port.irq;
+
+	qe_port->us_info.rx_bd_ring_len = qe_port->rx_nrfifos;
+	qe_port->us_info.tx_bd_ring_len = qe_port->tx_nrfifos;
+
+	/* Make sure ucc_slow_init() initializes both TX and RX */
+	qe_port->us_info.init_tx = 1;
+	qe_port->us_info.init_rx = 1;
+
+	/* Add the port to the uart sub-system.  This will cause
+	 * qe_uart_config_port() to be called, so the us_info structure must
+	 * be initialized.
+	 */
+	ret = uart_add_one_port(&ucc_uart_driver, &qe_port->port);
+	if (ret) {
+		dev_err(&ofdev->dev, "could not add /dev/ttyQE%u\n",
+		       qe_port->port.line);
+		kfree(qe_port);
+		return ret;
+	}
+
+	dev_set_drvdata(&ofdev->dev, qe_port);
+
+	dev_info(&ofdev->dev, "UCC%u assigned to /dev/ttyQE%u\n",
+		qe_port->ucc_num + 1, qe_port->port.line);
+
+	/* Display the mknod command for this device */
+	dev_dbg(&ofdev->dev, "mknod command is 'mknod /dev/ttyQE%u c %u %u'\n",
+	       qe_port->port.line, SERIAL_QE_MAJOR,
+	       SERIAL_QE_MINOR + qe_port->port.line);
+
+	return 0;
+}
+
+static int ucc_uart_remove(struct of_device *ofdev)
+{
+	struct uart_qe_port *qe_port = dev_get_drvdata(&ofdev->dev);
+
+	dev_info(&ofdev->dev, "removing /dev/ttyQE%u\n", qe_port->port.line);
+
+	uart_remove_one_port(&ucc_uart_driver, &qe_port->port);
+
+	dev_set_drvdata(&ofdev->dev, NULL);
+	kfree(qe_port);
+
+	return 0;
+}
+
+static struct of_device_id ucc_uart_match[] = {
+	{
+		.type = "serial",
+		.compatible = "ucc_uart",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ucc_uart_match);
+
+static struct of_platform_driver ucc_uart_of_driver = {
+	.owner  	= THIS_MODULE,
+	.name   	= "ucc_uart",
+	.match_table    = ucc_uart_match,
+	.probe  	= ucc_uart_probe,
+	.remove 	= ucc_uart_remove,
+};
+
+static int __init ucc_uart_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "Freescale QUICC Engine UART device driver\n");
+#ifdef LOOPBACK
+	printk(KERN_INFO "ucc-uart: Using loopback mode\n");
+#endif
+
+	ret = uart_register_driver(&ucc_uart_driver);
+	if (ret) {
+		printk(KERN_ERR "ucc-uart: could not register UART driver\n");
+		return ret;
+	}
+
+	ret = of_register_platform_driver(&ucc_uart_of_driver);
+	if (ret)
+		printk(KERN_ERR
+		       "ucc-uart: could not register platform driver\n");
+
+	return ret;
+}
+
+static void __exit ucc_uart_exit(void)
+{
+	printk(KERN_INFO
+	       "Freescale QUICC Engine UART device driver unloading\n");
+
+	of_unregister_platform_driver(&ucc_uart_of_driver);
+	uart_unregister_driver(&ucc_uart_driver);
+}
+
+module_init(ucc_uart_init);
+module_exit(ucc_uart_exit);
+
+MODULE_DESCRIPTION("Freescale QUICC Engine (QE) UART");
+MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_QE_MAJOR);
+