4 files changed, 184 insertions, 131 deletions

diff --git a/drivers/serial/amba-pl010.c b/drivers/serial/amba-pl010.c
index f69bd097166e..1a9a24b82636 100644
--- a/drivers/serial/amba-pl010.c
+++ b/drivers/serial/amba-pl010.c
@@ -48,6 +48,7 @@
 #include <linux/serial.h>
 #include <linux/amba/bus.h>
 #include <linux/amba/serial.h>
+#include <linux/clk.h>
 
 #include <asm/io.h>
 
@@ -70,6 +71,7 @@
  */
 struct uart_amba_port {
         struct uart_port        port;
+        struct clk              *clk;
         struct amba_device      *dev;
         struct amba_pl010_data  *data;
         unsigned int            old_status;
@@ -77,73 +79,77 @@ struct uart_amba_port {
 
 static void pl010_stop_tx(struct uart_port *port)
 {
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
         unsigned int cr;
 
-        cr = readb(port->membase + UART010_CR);
+        cr = readb(uap->port.membase + UART010_CR);
         cr &= ~UART010_CR_TIE;
-        writel(cr, port->membase + UART010_CR);
+        writel(cr, uap->port.membase + UART010_CR);
 }
 
 static void pl010_start_tx(struct uart_port *port)
 {
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
         unsigned int cr;
 
-        cr = readb(port->membase + UART010_CR);
+        cr = readb(uap->port.membase + UART010_CR);
         cr |= UART010_CR_TIE;
-        writel(cr, port->membase + UART010_CR);
+        writel(cr, uap->port.membase + UART010_CR);
 }
 
 static void pl010_stop_rx(struct uart_port *port)
 {
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
         unsigned int cr;
 
-        cr = readb(port->membase + UART010_CR);
+        cr = readb(uap->port.membase + UART010_CR);
         cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
-        writel(cr, port->membase + UART010_CR);
+        writel(cr, uap->port.membase + UART010_CR);
 }
 
 static void pl010_enable_ms(struct uart_port *port)
 {
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
         unsigned int cr;
 
-        cr = readb(port->membase + UART010_CR);
+        cr = readb(uap->port.membase + UART010_CR);
         cr |= UART010_CR_MSIE;
-        writel(cr, port->membase + UART010_CR);
+        writel(cr, uap->port.membase + UART010_CR);
 }
 
-static void pl010_rx_chars(struct uart_port *port)
+static void pl010_rx_chars(struct uart_amba_port *uap)
 {
-        struct tty_struct *tty = port->info->tty;
+        struct tty_struct *tty = uap->port.info->tty;
         unsigned int status, ch, flag, rsr, max_count = 256;
 
-        status = readb(port->membase + UART01x_FR);
+        status = readb(uap->port.membase + UART01x_FR);
         while (UART_RX_DATA(status) && max_count--) {
-                ch = readb(port->membase + UART01x_DR);
+                ch = readb(uap->port.membase + UART01x_DR);
                 flag = TTY_NORMAL;
 
-                port->icount.rx++;
+                uap->port.icount.rx++;
 
                 /*
                  * Note that the error handling code is
                  * out of the main execution path
                  */
-                rsr = readb(port->membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
+                rsr = readb(uap->port.membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
                 if (unlikely(rsr & UART01x_RSR_ANY)) {
-                        writel(0, port->membase + UART01x_ECR);
+                        writel(0, uap->port.membase + UART01x_ECR);
 
                         if (rsr & UART01x_RSR_BE) {
                                 rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
-                                port->icount.brk++;
-                                if (uart_handle_break(port))
+                                uap->port.icount.brk++;
+                                if (uart_handle_break(&uap->port))
                                         goto ignore_char;
                         } else if (rsr & UART01x_RSR_PE)
-                                port->icount.parity++;
+                                uap->port.icount.parity++;
                         else if (rsr & UART01x_RSR_FE)
-                                port->icount.frame++;
+                                uap->port.icount.frame++;
                         if (rsr & UART01x_RSR_OE)
-                                port->icount.overrun++;
+                                uap->port.icount.overrun++;
 
-                        rsr &= port->read_status_mask;
+                        rsr &= uap->port.read_status_mask;
 
                         if (rsr & UART01x_RSR_BE)
                                 flag = TTY_BREAK;
@@ -153,53 +159,52 @@ static void pl010_rx_chars(struct uart_port *port)
                                 flag = TTY_FRAME;
                 }
 
-                if (uart_handle_sysrq_char(port, ch))
+                if (uart_handle_sysrq_char(&uap->port, ch))
                         goto ignore_char;
 
-                uart_insert_char(port, rsr, UART01x_RSR_OE, ch, flag);
+                uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);
 
         ignore_char:
-                status = readb(port->membase + UART01x_FR);
+                status = readb(uap->port.membase + UART01x_FR);
         }
         tty_flip_buffer_push(tty);
         return;
 }
 
-static void pl010_tx_chars(struct uart_port *port)
+static void pl010_tx_chars(struct uart_amba_port *uap)
 {
-        struct circ_buf *xmit = &port->info->xmit;
+        struct circ_buf *xmit = &uap->port.info->xmit;
         int count;
 
-        if (port->x_char) {
-                writel(port->x_char, port->membase + UART01x_DR);
-                port->icount.tx++;
-                port->x_char = 0;
+        if (uap->port.x_char) {
+                writel(uap->port.x_char, uap->port.membase + UART01x_DR);
+                uap->port.icount.tx++;
+                uap->port.x_char = 0;
                 return;
         }
-        if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
-                pl010_stop_tx(port);
+        if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
+                pl010_stop_tx(&uap->port);
                 return;
         }
 
-        count = port->fifosize >> 1;
+        count = uap->port.fifosize >> 1;
         do {
-                writel(xmit->buf[xmit->tail], port->membase + UART01x_DR);
+                writel(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
-                port->icount.tx++;
+                uap->port.icount.tx++;
                 if (uart_circ_empty(xmit))
                         break;
         } while (--count > 0);
 
         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
-                uart_write_wakeup(port);
+                uart_write_wakeup(&uap->port);
 
         if (uart_circ_empty(xmit))
-                pl010_stop_tx(port);
+                pl010_stop_tx(&uap->port);
 }
 
-static void pl010_modem_status(struct uart_port *port)
+static void pl010_modem_status(struct uart_amba_port *uap)
 {
-        struct uart_amba_port *uap = (struct uart_amba_port *)port;
         unsigned int status, delta;
 
         writel(0, uap->port.membase + UART010_ICR);
@@ -226,47 +231,50 @@ static void pl010_modem_status(struct uart_port *port)
 
 static irqreturn_t pl010_int(int irq, void *dev_id)
 {
-        struct uart_port *port = dev_id;
+        struct uart_amba_port *uap = dev_id;
         unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
         int handled = 0;
 
-        spin_lock(&port->lock);
+        spin_lock(&uap->port.lock);
 
-        status = readb(port->membase + UART010_IIR);
+        status = readb(uap->port.membase + UART010_IIR);
         if (status) {
                 do {
                         if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
-                                pl010_rx_chars(port);
+                                pl010_rx_chars(uap);
                         if (status & UART010_IIR_MIS)
-                                pl010_modem_status(port);
+                                pl010_modem_status(uap);
                         if (status & UART010_IIR_TIS)
-                                pl010_tx_chars(port);
+                                pl010_tx_chars(uap);
 
                         if (pass_counter-- == 0)
                                 break;
 
-                        status = readb(port->membase + UART010_IIR);
+                        status = readb(uap->port.membase + UART010_IIR);
                 } while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
                                    UART010_IIR_TIS));
                 handled = 1;
         }
 
-        spin_unlock(&port->lock);
+        spin_unlock(&uap->port.lock);
 
         return IRQ_RETVAL(handled);
 }
 
 static unsigned int pl010_tx_empty(struct uart_port *port)
 {
-        return readb(port->membase + UART01x_FR) & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
+        unsigned int status = readb(uap->port.membase + UART01x_FR);
+        return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
 }
 
 static unsigned int pl010_get_mctrl(struct uart_port *port)
 {
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
         unsigned int result = 0;
         unsigned int status;
 
-        status = readb(port->membase + UART01x_FR);
+        status = readb(uap->port.membase + UART01x_FR);
         if (status & UART01x_FR_DCD)
                 result |= TIOCM_CAR;
         if (status & UART01x_FR_DSR)
@@ -287,17 +295,18 @@ static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
 
 static void pl010_break_ctl(struct uart_port *port, int break_state)
 {
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
         unsigned long flags;
         unsigned int lcr_h;
 
-        spin_lock_irqsave(&port->lock, flags);
-        lcr_h = readb(port->membase + UART010_LCRH);
+        spin_lock_irqsave(&uap->port.lock, flags);
+        lcr_h = readb(uap->port.membase + UART010_LCRH);
         if (break_state == -1)
                 lcr_h |= UART01x_LCRH_BRK;
         else
                 lcr_h &= ~UART01x_LCRH_BRK;
-        writel(lcr_h, port->membase + UART010_LCRH);
-        spin_unlock_irqrestore(&port->lock, flags);
+        writel(lcr_h, uap->port.membase + UART010_LCRH);
+        spin_unlock_irqrestore(&uap->port.lock, flags);
 }
 
 static int pl010_startup(struct uart_port *port)
@@ -306,48 +315,70 @@ static int pl010_startup(struct uart_port *port)
         int retval;
 
         /*
+         * Try to enable the clock producer.
+         */
+        retval = clk_enable(uap->clk);
+        if (retval)
+                goto out;
+
+        uap->port.uartclk = clk_get_rate(uap->clk);
+
+        /*
          * Allocate the IRQ
          */
-        retval = request_irq(port->irq, pl010_int, 0, "uart-pl010", port);
+        retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
         if (retval)
-                return retval;
+                goto clk_dis;
 
         /*
          * initialise the old status of the modem signals
          */
-        uap->old_status = readb(port->membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
+        uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
 
         /*
          * Finally, enable interrupts
          */
         writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
-               port->membase + UART010_CR);
+               uap->port.membase + UART010_CR);
 
         return 0;
+
+ clk_dis:
+        clk_disable(uap->clk);
+ out:
+        return retval;
 }
 
 static void pl010_shutdown(struct uart_port *port)
 {
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
+
         /*
          * Free the interrupt
          */
-        free_irq(port->irq, port);
+        free_irq(uap->port.irq, uap);
 
         /*
          * disable all interrupts, disable the port
          */
-        writel(0, port->membase + UART010_CR);
+        writel(0, uap->port.membase + UART010_CR);
 
         /* disable break condition and fifos */
-        writel(readb(port->membase + UART010_LCRH) &
+        writel(readb(uap->port.membase + UART010_LCRH) &
                 ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
-               port->membase + UART010_LCRH);
+               uap->port.membase + UART010_LCRH);
+
+        /*
+         * Shut down the clock producer
+         */
+        clk_disable(uap->clk);
 }
 
 static void
 pl010_set_termios(struct uart_port *port, struct ktermios *termios,
                      struct ktermios *old)
 {
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
         unsigned int lcr_h, old_cr;
         unsigned long flags;
         unsigned int baud, quot;
@@ -355,7 +386,7 @@ pl010_set_termios(struct uart_port *port, struct ktermios *termios,
         /*
          * Ask the core to calculate the divisor for us.
          */
-        baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); 
+        baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16); 
         quot = uart_get_divisor(port, baud);
 
         switch (termios->c_cflag & CSIZE) {
@@ -379,66 +410,66 @@ pl010_set_termios(struct uart_port *port, struct ktermios *termios,
                 if (!(termios->c_cflag & PARODD))
                         lcr_h |= UART01x_LCRH_EPS;
         }
-        if (port->fifosize > 1)
+        if (uap->port.fifosize > 1)
                 lcr_h |= UART01x_LCRH_FEN;
 
-        spin_lock_irqsave(&port->lock, flags);
+        spin_lock_irqsave(&uap->port.lock, flags);
 
         /*
          * Update the per-port timeout.
          */
         uart_update_timeout(port, termios->c_cflag, baud);
 
-        port->read_status_mask = UART01x_RSR_OE;
+        uap->port.read_status_mask = UART01x_RSR_OE;
         if (termios->c_iflag & INPCK)
-                port->read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
+                uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
         if (termios->c_iflag & (BRKINT | PARMRK))
-                port->read_status_mask |= UART01x_RSR_BE;
+                uap->port.read_status_mask |= UART01x_RSR_BE;
 
         /*
          * Characters to ignore
          */
-        port->ignore_status_mask = 0;
+        uap->port.ignore_status_mask = 0;
         if (termios->c_iflag & IGNPAR)
-                port->ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
+                uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
         if (termios->c_iflag & IGNBRK) {
-                port->ignore_status_mask |= UART01x_RSR_BE;
+                uap->port.ignore_status_mask |= UART01x_RSR_BE;
                 /*
                  * If we're ignoring parity and break indicators,
                  * ignore overruns too (for real raw support).
                  */
                 if (termios->c_iflag & IGNPAR)
-                        port->ignore_status_mask |= UART01x_RSR_OE;
+                        uap->port.ignore_status_mask |= UART01x_RSR_OE;
         }
 
         /*
          * Ignore all characters if CREAD is not set.
          */
         if ((termios->c_cflag & CREAD) == 0)
-                port->ignore_status_mask |= UART_DUMMY_RSR_RX;
+                uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;
 
         /* first, disable everything */
-        old_cr = readb(port->membase + UART010_CR) & ~UART010_CR_MSIE;
+        old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;
 
         if (UART_ENABLE_MS(port, termios->c_cflag))
                 old_cr |= UART010_CR_MSIE;
 
-        writel(0, port->membase + UART010_CR);
+        writel(0, uap->port.membase + UART010_CR);
 
         /* Set baud rate */
         quot -= 1;
-        writel((quot & 0xf00) >> 8, port->membase + UART010_LCRM);
-        writel(quot & 0xff, port->membase + UART010_LCRL);
+        writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
+        writel(quot & 0xff, uap->port.membase + UART010_LCRL);
 
         /*
          * ----------v----------v----------v----------v-----
          * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
          * ----------^----------^----------^----------^-----
          */
-        writel(lcr_h, port->membase + UART010_LCRH);
-        writel(old_cr, port->membase + UART010_CR);
+        writel(lcr_h, uap->port.membase + UART010_LCRH);
+        writel(old_cr, uap->port.membase + UART010_CR);
 
-        spin_unlock_irqrestore(&port->lock, flags);
+        spin_unlock_irqrestore(&uap->port.lock, flags);
 }
 
 static const char *pl010_type(struct uart_port *port)
@@ -514,47 +545,52 @@ static struct uart_amba_port *amba_ports[UART_NR];
 
 static void pl010_console_putchar(struct uart_port *port, int ch)
 {
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
         unsigned int status;
 
         do {
-                status = readb(port->membase + UART01x_FR);
+                status = readb(uap->port.membase + UART01x_FR);
                 barrier();
         } while (!UART_TX_READY(status));
-        writel(ch, port->membase + UART01x_DR);
+        writel(ch, uap->port.membase + UART01x_DR);
 }
 
 static void
 pl010_console_write(struct console *co, const char *s, unsigned int count)
 {
-        struct uart_port *port = &amba_ports[co->index]->port;
+        struct uart_amba_port *uap = amba_ports[co->index];
         unsigned int status, old_cr;
 
+        clk_enable(uap->clk);
+
         /*
          *      First save the CR then disable the interrupts
          */
-        old_cr = readb(port->membase + UART010_CR);
-        writel(UART01x_CR_UARTEN, port->membase + UART010_CR);
+        old_cr = readb(uap->port.membase + UART010_CR);
+        writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);
 
-        uart_console_write(port, s, count, pl010_console_putchar);
+        uart_console_write(&uap->port, s, count, pl010_console_putchar);
 
         /*
          *      Finally, wait for transmitter to become empty
          *      and restore the TCR
          */
         do {
-                status = readb(port->membase + UART01x_FR);
+                status = readb(uap->port.membase + UART01x_FR);
                 barrier();
         } while (status & UART01x_FR_BUSY);
-        writel(old_cr, port->membase + UART010_CR);
+        writel(old_cr, uap->port.membase + UART010_CR);
+
+        clk_disable(uap->clk);
 }
 
 static void __init
-pl010_console_get_options(struct uart_port *port, int *baud,
+pl010_console_get_options(struct uart_amba_port *uap, int *baud,
                              int *parity, int *bits)
 {
-        if (readb(port->membase + UART010_CR) & UART01x_CR_UARTEN) {
+        if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
                 unsigned int lcr_h, quot;
-                lcr_h = readb(port->membase + UART010_LCRH);
+                lcr_h = readb(uap->port.membase + UART010_LCRH);
 
                 *parity = 'n';
                 if (lcr_h & UART01x_LCRH_PEN) {
@@ -569,14 +605,15 @@ pl010_console_get_options(struct uart_port *port, int *baud,
                 else
                         *bits = 8;
 
-                quot = readb(port->membase + UART010_LCRL) | readb(port->membase + UART010_LCRM) << 8;
-                *baud = port->uartclk / (16 * (quot + 1));
+                quot = readb(uap->port.membase + UART010_LCRL) |
+                       readb(uap->port.membase + UART010_LCRM) << 8;
+                *baud = uap->port.uartclk / (16 * (quot + 1));
         }
 }
 
 static int __init pl010_console_setup(struct console *co, char *options)
 {
-        struct uart_port *port;
+        struct uart_amba_port *uap;
         int baud = 38400;
         int bits = 8;
         int parity = 'n';
@@ -589,16 +626,18 @@ static int __init pl010_console_setup(struct console *co, char *options)
          */
         if (co->index >= UART_NR)
                 co->index = 0;
-        if (!amba_ports[co->index])
+        uap = amba_ports[co->index];
+        if (!uap)
                 return -ENODEV;
-        port = &amba_ports[co->index]->port;
+
+        uap->port.uartclk = clk_get_rate(uap->clk);
 
         if (options)
                 uart_parse_options(options, &baud, &parity, &bits, &flow);
         else
-                pl010_console_get_options(port, &baud, &parity, &bits);
+                pl010_console_get_options(uap, &baud, &parity, &bits);
 
-        return uart_set_options(port, co, baud, parity, bits, flow);
+        return uart_set_options(&uap->port, co, baud, parity, bits, flow);
 }
 
 static struct uart_driver amba_reg;
@@ -629,7 +668,7 @@ static struct uart_driver amba_reg = {
 
 static int pl010_probe(struct amba_device *dev, void *id)
 {
-        struct uart_amba_port *port;
+        struct uart_amba_port *uap;
         void __iomem *base;
         int i, ret;
 
@@ -642,8 +681,8 @@ static int pl010_probe(struct amba_device *dev, void *id)
                 goto out;
         }
 
-        port = kzalloc(sizeof(struct uart_amba_port), GFP_KERNEL);
-        if (!port) {
+        uap = kzalloc(sizeof(struct uart_amba_port), GFP_KERNEL);
+        if (!uap) {
                 ret = -ENOMEM;
                 goto out;
         }
@@ -654,51 +693,57 @@ static int pl010_probe(struct amba_device *dev, void *id)
                 goto free;
         }
 
-        port->port.dev = &dev->dev;
-        port->port.mapbase = dev->res.start;
-        port->port.membase = base;
-        port->port.iotype = UPIO_MEM;
-        port->port.irq = dev->irq[0];
-        port->port.uartclk = 14745600;
-        port->port.fifosize = 16;
-        port->port.ops = &amba_pl010_pops;
-        port->port.flags = UPF_BOOT_AUTOCONF;
-        port->port.line = i;
-        port->dev = dev;
-        port->data = dev->dev.platform_data;
-
-        amba_ports[i] = port;
-
-        amba_set_drvdata(dev, port);
-        ret = uart_add_one_port(&amba_reg, &port->port);
+        uap->clk = clk_get(&dev->dev, "UARTCLK");
+        if (IS_ERR(uap->clk)) {
+                ret = PTR_ERR(uap->clk);
+                goto unmap;
+        }
+
+        uap->port.dev = &dev->dev;
+        uap->port.mapbase = dev->res.start;
+        uap->port.membase = base;
+        uap->port.iotype = UPIO_MEM;
+        uap->port.irq = dev->irq[0];
+        uap->port.fifosize = 16;
+        uap->port.ops = &amba_pl010_pops;
+        uap->port.flags = UPF_BOOT_AUTOCONF;
+        uap->port.line = i;
+        uap->dev = dev;
+        uap->data = dev->dev.platform_data;
+
+        amba_ports[i] = uap;
+
+        amba_set_drvdata(dev, uap);
+        ret = uart_add_one_port(&amba_reg, &uap->port);
         if (ret) {
                 amba_set_drvdata(dev, NULL);
                 amba_ports[i] = NULL;
+                clk_put(uap->clk);
+ unmap:
                 iounmap(base);
  free:
-                kfree(port);
+                kfree(uap);
         }
-
  out:
         return ret;
 }
 
 static int pl010_remove(struct amba_device *dev)
 {
-        struct uart_amba_port *port = amba_get_drvdata(dev);
+        struct uart_amba_port *uap = amba_get_drvdata(dev);
         int i;
 
         amba_set_drvdata(dev, NULL);
 
-        uart_remove_one_port(&amba_reg, &port->port);
+        uart_remove_one_port(&amba_reg, &uap->port);
 
         for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
-                if (amba_ports[i] == port)
+                if (amba_ports[i] == uap)
                         amba_ports[i] = NULL;
 
-        iounmap(port->port.membase);
-        kfree(port);
-
+        iounmap(uap->port.membase);
+        clk_put(uap->clk);
+        kfree(uap);
         return 0;
 }
 
diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index 935f48fa501d..3320bcd92c0a 100644
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -484,11 +484,16 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios * termios,
         unsigned long flags;
         unsigned int mode, imr, quot, baud;
 
+        /* Get current mode register */
+        mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL | ATMEL_US_NBSTOP | ATMEL_US_PAR);
+
         baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
         quot = uart_get_divisor(port, baud);
 
-        /* Get current mode register */
-        mode = UART_GET_MR(port) & ~(ATMEL_US_CHRL | ATMEL_US_NBSTOP | ATMEL_US_PAR);
+        if (quot > 65535) {             /* BRGR is 16-bit, so switch to slower clock */
+                quot /= 8;
+                mode |= ATMEL_US_USCLKS_MCK_DIV8;
+        }
 
         /* byte size */
         switch (termios->c_cflag & CSIZE) {
diff --git a/drivers/serial/atmel_serial.h b/drivers/serial/atmel_serial.h
index 11b44360e108..e0141776517c 100644
--- a/drivers/serial/atmel_serial.h
+++ b/drivers/serial/atmel_serial.h
@@ -46,6 +46,9 @@
 #define                 ATMEL_US_USMODE_ISO7816_T1      6
 #define                 ATMEL_US_USMODE_IRDA            8
 #define         ATMEL_US_USCLKS         (3   <<  4)             /* Clock Selection */
+#define                 ATMEL_US_USCLKS_MCK             (0 <<  4)
+#define                 ATMEL_US_USCLKS_MCK_DIV8        (1 <<  4)
+#define                 ATMEL_US_USCLKS_SCK             (3 <<  4)
 #define         ATMEL_US_CHRL           (3   <<  6)             /* Character Length */
 #define                 ATMEL_US_CHRL_5                 (0 <<  6)
 #define                 ATMEL_US_CHRL_6                 (1 <<  6)
diff --git a/drivers/serial/pxa.c b/drivers/serial/pxa.c
index d403aaa55092..e9c6cb391a23 100644
--- a/drivers/serial/pxa.c
+++ b/drivers/serial/pxa.c
@@ -717,7 +717,7 @@ struct uart_ops serial_pxa_pops = {
 static struct uart_pxa_port serial_pxa_ports[] = {
      {  /* FFUART */
         .name   = "FFUART",
-        .cken   = CKEN6_FFUART,
+        .cken   = CKEN_FFUART,
         .port   = {
                 .type           = PORT_PXA,
                 .iotype         = UPIO_MEM,
@@ -731,7 +731,7 @@ static struct uart_pxa_port serial_pxa_ports[] = {
         },
   }, {  /* BTUART */
         .name   = "BTUART",
-        .cken   = CKEN7_BTUART,
+        .cken   = CKEN_BTUART,
         .port   = {
                 .type           = PORT_PXA,
                 .iotype         = UPIO_MEM,
@@ -745,7 +745,7 @@ static struct uart_pxa_port serial_pxa_ports[] = {
         },
   }, {  /* STUART */
         .name   = "STUART",
-        .cken   = CKEN5_STUART,
+        .cken   = CKEN_STUART,
         .port   = {
                 .type           = PORT_PXA,
                 .iotype         = UPIO_MEM,
@@ -759,7 +759,7 @@ static struct uart_pxa_port serial_pxa_ports[] = {
         },
   }, {  /* HWUART */
         .name   = "HWUART",
-        .cken   = CKEN4_HWUART,
+        .cken   = CKEN_HWUART,
         .port = {
                 .type           = PORT_PXA,
                 .iotype         = UPIO_MEM,