[ARM] 3592/1: AT91RM9200 Serial driver update

Patch from Andrew Victor

This patch includes a number of updates to the AT91RM9200 serial driver.

Changes include:
1. Conversion to a platform_driver.  [Ivan Kokshaysky]
2. Replaced all references to AT91RM9200 with AT91.  This driver can now
also be used for the AT91SAM9216.
3. Allow TIOCM_LOOP to configure local loopback mode.
4. Cleaned up the 'read_status_mask' usage and interrupt handler code.
[Chip Coldwell]
5. Suspend/resume support.  [David Brownell]

There are a few 'unused variable' warning when compiling this - I
removed the new DMA support to keep this first patch simpler.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 280 insertions, 183 deletions

diff --git a/drivers/serial/at91_serial.c b/drivers/serial/at91_serial.c
index 6547fe0cef96..db5b25fafed4 100644
--- a/drivers/serial/at91_serial.c
+++ b/drivers/serial/at91_serial.c
@@ -2,7 +2,6 @@
  *  linux/drivers/char/at91_serial.c
  *
  *  Driver for Atmel AT91RM9200 Serial ports
- *
  *  Copyright (C) 2003 Rick Bronson
  *
  *  Based on drivers/char/serial_sa1100.c, by Deep Blue Solutions Ltd.
@@ -30,17 +29,19 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/serial.h>
+#include <linux/clk.h>
 #include <linux/console.h>
 #include <linux/sysrq.h>
 #include <linux/tty_flip.h>
+#include <linux/platform_device.h>
 
 #include <asm/io.h>
 
 #include <asm/arch/at91rm9200_usart.h>
-#include <asm/mach/serial_at91rm9200.h>
+#include <asm/arch/at91rm9200_pdc.h>
+#include <asm/mach/serial_at91.h>
 #include <asm/arch/board.h>
-#include <asm/arch/pio.h>
-
+#include <asm/arch/system.h>
 
 #if defined(CONFIG_SERIAL_AT91_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
 #define SUPPORT_SYSRQ
@@ -67,7 +68,6 @@
 
 #endif
 
-#define AT91_VA_BASE_DBGU       ((unsigned long) AT91_VA_BASE_SYS + AT91_DBGU)
 #define AT91_ISR_PASS_LIMIT     256
 
 #define UART_PUT_CR(port,v)     writel(v, (port)->membase + AT91_US_CR)
@@ -87,16 +87,33 @@
 
  /* PDC registers */
 #define UART_PUT_PTCR(port,v)   writel(v, (port)->membase + AT91_PDC_PTCR)
+#define UART_GET_PTSR(port)     readl((port)->membase + AT91_PDC_PTSR)
+
 #define UART_PUT_RPR(port,v)    writel(v, (port)->membase + AT91_PDC_RPR)
+#define UART_GET_RPR(port)      readl((port)->membase + AT91_PDC_RPR)
 #define UART_PUT_RCR(port,v)    writel(v, (port)->membase + AT91_PDC_RCR)
-#define UART_GET_RCR(port)      readl((port)->membase + AT91_PDC_RCR)
 #define UART_PUT_RNPR(port,v)   writel(v, (port)->membase + AT91_PDC_RNPR)
 #define UART_PUT_RNCR(port,v)   writel(v, (port)->membase + AT91_PDC_RNCR)
 
+#define UART_PUT_TPR(port,v)    writel(v, (port)->membase + AT91_PDC_TPR)
+#define UART_PUT_TCR(port,v)    writel(v, (port)->membase + AT91_PDC_TCR)
+//#define UART_PUT_TNPR(port,v) writel(v, (port)->membase + AT91_PDC_TNPR)
+//#define UART_PUT_TNCR(port,v) writel(v, (port)->membase + AT91_PDC_TNCR)
 
 static int (*at91_open)(struct uart_port *);
 static void (*at91_close)(struct uart_port *);
 
+/*
+ * We wrap our port structure around the generic uart_port.
+ */
+struct at91_uart_port {
+        struct uart_port        uart;           /* uart */
+        struct clk              *clk;           /* uart clock */
+        unsigned short          suspended;      /* is port suspended? */
+};
+
+static struct at91_uart_port at91_ports[AT91_NR_UART];
+
 #ifdef SUPPORT_SYSRQ
 static struct console at91_console;
 #endif
@@ -115,16 +132,19 @@ static u_int at91_tx_empty(struct uart_port *port)
 static void at91_set_mctrl(struct uart_port *port, u_int mctrl)
 {
         unsigned int control = 0;
+        unsigned int mode;
 
-        /*
-         * Errata #39: RTS0 is not internally connected to PA21.  We need to drive
-         *  the pin manually.
-         */
-        if (port->mapbase == AT91_VA_BASE_US0) {
-                if (mctrl & TIOCM_RTS)
-                        at91_sys_write(AT91_PIOA + PIO_CODR, AT91_PA21_RTS0);
-                else
-                        at91_sys_write(AT91_PIOA + PIO_SODR, AT91_PA21_RTS0);
+        if (arch_identify() == ARCH_ID_AT91RM9200) {
+                /*
+                 * AT91RM9200 Errata #39: RTS0 is not internally connected to PA21.
+                 *  We need to drive the pin manually.
+                 */
+                if (port->mapbase == AT91_BASE_US0) {
+                        if (mctrl & TIOCM_RTS)
+                                at91_sys_write(AT91_PIOA + PIO_CODR, AT91_PA21_RTS0);
+                        else
+                                at91_sys_write(AT91_PIOA + PIO_SODR, AT91_PA21_RTS0);
+                }
         }
 
         if (mctrl & TIOCM_RTS)
@@ -137,7 +157,15 @@ static void at91_set_mctrl(struct uart_port *port, u_int mctrl)
         else
                 control |= AT91_US_DTRDIS;
 
-        UART_PUT_CR(port,control);
+        UART_PUT_CR(port, control);
+
+        /* Local loopback mode? */
+        mode = UART_GET_MR(port) & ~AT91_US_CHMODE;
+        if (mctrl & TIOCM_LOOP)
+                mode |= AT91_US_CHMODE_LOC_LOOP;
+        else
+                mode |= AT91_US_CHMODE_NORMAL;
+        UART_PUT_MR(port, mode);
 }
 
 /*
@@ -169,8 +197,9 @@ static u_int at91_get_mctrl(struct uart_port *port)
  */
 static void at91_stop_tx(struct uart_port *port)
 {
+        struct at91_uart_port *at91_port = (struct at91_uart_port *) port;
+
         UART_PUT_IDR(port, AT91_US_TXRDY);
-        port->read_status_mask &= ~AT91_US_TXRDY;
 }
 
 /*
@@ -178,7 +207,8 @@ static void at91_stop_tx(struct uart_port *port)
  */
 static void at91_start_tx(struct uart_port *port)
 {
-        port->read_status_mask |= AT91_US_TXRDY;
+        struct at91_uart_port *at91_port = (struct at91_uart_port *) port;
+
         UART_PUT_IER(port, AT91_US_TXRDY);
 }
 
@@ -187,6 +217,8 @@ static void at91_start_tx(struct uart_port *port)
  */
 static void at91_stop_rx(struct uart_port *port)
 {
+        struct at91_uart_port *at91_port = (struct at91_uart_port *) port;
+
         UART_PUT_IDR(port, AT91_US_RXRDY);
 }
 
@@ -195,7 +227,6 @@ static void at91_stop_rx(struct uart_port *port)
  */
 static void at91_enable_ms(struct uart_port *port)
 {
-        port->read_status_mask |= (AT91_US_RIIC | AT91_US_DSRIC | AT91_US_DCDIC | AT91_US_CTSIC);
         UART_PUT_IER(port, AT91_US_RIIC | AT91_US_DSRIC | AT91_US_DCDIC | AT91_US_CTSIC);
 }
 
@@ -218,8 +249,8 @@ static void at91_rx_chars(struct uart_port *port, struct pt_regs *regs)
         struct tty_struct *tty = port->info->tty;
         unsigned int status, ch, flg;
 
-        status = UART_GET_CSR(port) & port->read_status_mask;
-        while (status & (AT91_US_RXRDY)) {
+        status = UART_GET_CSR(port);
+        while (status & AT91_US_RXRDY) {
                 ch = UART_GET_CHAR(port);
 
                 port->icount.rx++;
@@ -230,40 +261,38 @@ static void at91_rx_chars(struct uart_port *port, struct pt_regs *regs)
                  * note that the error handling code is
                  * out of the main execution path
                  */
-                if (unlikely(status & (AT91_US_PARE | AT91_US_FRAME | AT91_US_OVRE))) {
+                if (unlikely(status & (AT91_US_PARE | AT91_US_FRAME | AT91_US_OVRE | AT91_US_RXBRK))) {
                         UART_PUT_CR(port, AT91_US_RSTSTA);      /* clear error */
-                        if (status & (AT91_US_PARE))
+                        if (status & AT91_US_RXBRK) {
+                                status &= ~(AT91_US_PARE | AT91_US_FRAME);      /* ignore side-effect */
+                                port->icount.brk++;
+                                if (uart_handle_break(port))
+                                        goto ignore_char;
+                        }
+                        if (status & AT91_US_PARE)
                                 port->icount.parity++;
-                        if (status & (AT91_US_FRAME))
+                        if (status & AT91_US_FRAME)
                                 port->icount.frame++;
-                        if (status & (AT91_US_OVRE))
+                        if (status & AT91_US_OVRE)
                                 port->icount.overrun++;
 
-                        if (status & AT91_US_PARE)
+                        status &= port->read_status_mask;
+
+                        if (status & AT91_US_RXBRK)
+                                flg = TTY_BREAK;
+                        else if (status & AT91_US_PARE)
                                 flg = TTY_PARITY;
                         else if (status & AT91_US_FRAME)
                                 flg = TTY_FRAME;
-                        if (status & AT91_US_OVRE) {
-                                /*
-                                 * overrun does *not* affect the character
-                                 * we read from the FIFO
-                                 */
-                                tty_insert_flip_char(tty, ch, flg);
-                                ch = 0;
-                                flg = TTY_OVERRUN;
-                        }
-#ifdef SUPPORT_SYSRQ
-                        port->sysrq = 0;
-#endif
                 }
 
                 if (uart_handle_sysrq_char(port, ch, regs))
                         goto ignore_char;
 
-                tty_insert_flip_char(tty, ch, flg);
+                uart_insert_char(port, status, AT91_US_OVRE, ch, flg);
 
         ignore_char:
-                status = UART_GET_CSR(port) & port->read_status_mask;
+                status = UART_GET_CSR(port);
         }
 
         tty_flip_buffer_push(tty);
@@ -308,40 +337,35 @@ static void at91_tx_chars(struct uart_port *port)
 static irqreturn_t at91_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
         struct uart_port *port = dev_id;
+        struct at91_uart_port *at91_port = (struct at91_uart_port *) port;
         unsigned int status, pending, pass_counter = 0;
 
         status = UART_GET_CSR(port);
-        pending = status & port->read_status_mask;
-        if (pending) {
-                do {
-                        if (pending & AT91_US_RXRDY)
-                                at91_rx_chars(port, regs);
-
-                        /* Clear the relevent break bits */
-                        if (pending & AT91_US_RXBRK) {
-                                UART_PUT_CR(port, AT91_US_RSTSTA);
-                                port->icount.brk++;
-                                uart_handle_break(port);
-                        }
+        pending = status & UART_GET_IMR(port);
+        while (pending) {
+                /* Interrupt receive */
+                if (pending & AT91_US_RXRDY)
+                        at91_rx_chars(port, regs);
+
+                // TODO: All reads to CSR will clear these interrupts!
+                if (pending & AT91_US_RIIC) port->icount.rng++;
+                if (pending & AT91_US_DSRIC) port->icount.dsr++;
+                if (pending & AT91_US_DCDIC)
+                        uart_handle_dcd_change(port, !(status & AT91_US_DCD));
+                if (pending & AT91_US_CTSIC)
+                        uart_handle_cts_change(port, !(status & AT91_US_CTS));
+                if (pending & (AT91_US_RIIC | AT91_US_DSRIC | AT91_US_DCDIC | AT91_US_CTSIC))
+                        wake_up_interruptible(&port->info->delta_msr_wait);
+
+                /* Interrupt transmit */
+                if (pending & AT91_US_TXRDY)
+                        at91_tx_chars(port);
+
+                if (pass_counter++ > AT91_ISR_PASS_LIMIT)
+                        break;
 
-                        // TODO: All reads to CSR will clear these interrupts!
-                        if (pending & AT91_US_RIIC) port->icount.rng++;
-                        if (pending & AT91_US_DSRIC) port->icount.dsr++;
-                        if (pending & AT91_US_DCDIC)
-                                uart_handle_dcd_change(port, !(status & AT91_US_DCD));
-                        if (pending & AT91_US_CTSIC)
-                                uart_handle_cts_change(port, !(status & AT91_US_CTS));
-                        if (pending & (AT91_US_RIIC | AT91_US_DSRIC | AT91_US_DCDIC | AT91_US_CTSIC))
-                                wake_up_interruptible(&port->info->delta_msr_wait);
-
-                        if (pending & AT91_US_TXRDY)
-                                at91_tx_chars(port);
-                        if (pass_counter++ > AT91_ISR_PASS_LIMIT)
-                                break;
-
-                        status = UART_GET_CSR(port);
-                        pending = status & port->read_status_mask;
-                } while (pending);
+                status = UART_GET_CSR(port);
+                pending = status & UART_GET_IMR(port);
         }
         return IRQ_HANDLED;
 }
@@ -351,6 +375,7 @@ static irqreturn_t at91_interrupt(int irq, void *dev_id, struct pt_regs *regs)
  */
 static int at91_startup(struct uart_port *port)
 {
+        struct at91_uart_port *at91_port = (struct at91_uart_port *) port;
         int retval;
 
         /*
@@ -381,14 +406,14 @@ static int at91_startup(struct uart_port *port)
                 }
         }
 
-        port->read_status_mask = AT91_US_RXRDY | AT91_US_TXRDY | AT91_US_OVRE
-                        | AT91_US_FRAME | AT91_US_PARE | AT91_US_RXBRK;
         /*
          * Finally, enable the serial port
          */
         UART_PUT_CR(port, AT91_US_RSTSTA | AT91_US_RSTRX);
         UART_PUT_CR(port, AT91_US_TXEN | AT91_US_RXEN);         /* enable xmit & rcvr */
-        UART_PUT_IER(port, AT91_US_RXRDY);                      /* do receive only */
+
+        UART_PUT_IER(port, AT91_US_RXRDY);              /* enable receive only */
+
         return 0;
 }
 
@@ -397,6 +422,8 @@ static int at91_startup(struct uart_port *port)
  */
 static void at91_shutdown(struct uart_port *port)
 {
+        struct at91_uart_port *at91_port = (struct at91_uart_port *) port;
+
         /*
          * Disable all interrupts, port and break condition.
          */
@@ -421,21 +448,22 @@ static void at91_shutdown(struct uart_port *port)
  */
 static void at91_serial_pm(struct uart_port *port, unsigned int state, unsigned int oldstate)
 {
+        struct at91_uart_port *at91_port = (struct at91_uart_port *) port;
+
         switch (state) {
                 case 0:
                         /*
                          * Enable the peripheral clock for this serial port.
                          * This is called on uart_open() or a resume event.
                          */
-                        at91_sys_write(AT91_PMC_PCER, 1 << port->irq);
+                        clk_enable(at91_port->clk);
                         break;
                 case 3:
                         /*
                          * Disable the peripheral clock for this serial port.
                          * This is called on uart_close() or a suspend event.
                          */
-                        if (port->irq != AT91_ID_SYS)                   /* is this a shared clock? */
-                                at91_sys_write(AT91_PMC_PCDR, 1 << port->irq);
+                        clk_disable(at91_port->clk);
                         break;
                 default:
                         printk(KERN_ERR "at91_serial: unknown pm %d\n", state);
@@ -494,9 +522,9 @@ static void at91_set_termios(struct uart_port *port, struct termios * termios, s
 
         spin_lock_irqsave(&port->lock, flags);
 
-        port->read_status_mask |= AT91_US_OVRE;
+        port->read_status_mask = AT91_US_OVRE;
         if (termios->c_iflag & INPCK)
-                port->read_status_mask |= AT91_US_FRAME | AT91_US_PARE;
+                port->read_status_mask |= (AT91_US_FRAME | AT91_US_PARE);
         if (termios->c_iflag & (BRKINT | PARMRK))
                 port->read_status_mask |= AT91_US_RXBRK;
 
@@ -552,7 +580,7 @@ static void at91_set_termios(struct uart_port *port, struct termios * termios, s
  */
 static const char *at91_type(struct uart_port *port)
 {
-        return (port->type == PORT_AT91RM9200) ? "AT91_SERIAL" : NULL;
+        return (port->type == PORT_AT91) ? "AT91_SERIAL" : NULL;
 }
 
 /*
@@ -560,8 +588,15 @@ static const char *at91_type(struct uart_port *port)
  */
 static void at91_release_port(struct uart_port *port)
 {
-        release_mem_region(port->mapbase,
-                (port->mapbase == AT91_VA_BASE_DBGU) ? 512 : SZ_16K);
+        struct platform_device *pdev = to_platform_device(port->dev);
+        int size = pdev->resource[0].end - pdev->resource[0].start + 1;
+
+        release_mem_region(port->mapbase, size);
+
+        if (port->flags & UPF_IOREMAP) {
+                iounmap(port->membase);
+                port->membase = NULL;
+        }
 }
 
 /*
@@ -569,10 +604,21 @@ static void at91_release_port(struct uart_port *port)
  */
 static int at91_request_port(struct uart_port *port)
 {
-        return request_mem_region(port->mapbase,
-                (port->mapbase == AT91_VA_BASE_DBGU) ? 512 : SZ_16K,
-                "at91_serial") != NULL ? 0 : -EBUSY;
+        struct platform_device *pdev = to_platform_device(port->dev);
+        int size = pdev->resource[0].end - pdev->resource[0].start + 1;
+
+        if (!request_mem_region(port->mapbase, size, "at91_serial"))
+                return -EBUSY;
+
+        if (port->flags & UPF_IOREMAP) {
+                port->membase = ioremap(port->mapbase, size);
+                if (port->membase == NULL) {
+                        release_mem_region(port->mapbase, size);
+                        return -ENOMEM;
+                }
+        }
 
+        return 0;
 }
 
 /*
@@ -581,7 +627,7 @@ static int at91_request_port(struct uart_port *port)
 static void at91_config_port(struct uart_port *port, int flags)
 {
         if (flags & UART_CONFIG_TYPE) {
-                port->type = PORT_AT91RM9200;
+                port->type = PORT_AT91;
                 at91_request_port(port);
         }
 }
@@ -592,7 +638,7 @@ static void at91_config_port(struct uart_port *port, int flags)
 static int at91_verify_port(struct uart_port *port, struct serial_struct *ser)
 {
         int ret = 0;
-        if (ser->type != PORT_UNKNOWN && ser->type != PORT_AT91RM9200)
+        if (ser->type != PORT_UNKNOWN && ser->type != PORT_AT91)
                 ret = -EINVAL;
         if (port->irq != ser->irq)
                 ret = -EINVAL;
@@ -624,33 +670,47 @@ static struct uart_ops at91_pops = {
         .type           = at91_type,
         .release_port   = at91_release_port,
         .request_port   = at91_request_port,
-        .config_port    = at91_config_port,
-        .verify_port    = at91_verify_port,
+        .config_port    = at91_config_port,
+        .verify_port    = at91_verify_port,
         .pm             = at91_serial_pm,
 };
 
-static struct uart_port at91_ports[AT91_NR_UART];
-
-void __init at91_init_ports(void)
+/*
+ * Configure the port from the platform device resource info.
+ */
+static void __devinit at91_init_port(struct at91_uart_port *at91_port, struct platform_device *pdev)
 {
-        static int first = 1;
-        int i;
-
-        if (!first)
-                return;
-        first = 0;
+        struct uart_port *port = &at91_port->uart;
+        struct at91_uart_data *data = pdev->dev.platform_data;
+
+        port->iotype    = UPIO_MEM;
+        port->flags     = UPF_BOOT_AUTOCONF;
+        port->ops       = &at91_pops;
+        port->fifosize  = 1;
+        port->line      = pdev->id;
+        port->dev       = &pdev->dev;
+
+        port->mapbase   = pdev->resource[0].start;
+        port->irq       = pdev->resource[1].start;
+
+        if (port->mapbase == AT91_VA_BASE_SYS + AT91_DBGU)              /* Part of system perpherals - already mapped */
+                port->membase = (void __iomem *) port->mapbase;
+        else {
+                port->flags     |= UPF_IOREMAP;
+                port->membase   = NULL;
+        }
 
-        for (i = 0; i < AT91_NR_UART; i++) {
-                at91_ports[i].iotype    = UPIO_MEM;
-                at91_ports[i].flags     = UPF_BOOT_AUTOCONF;
-                at91_ports[i].uartclk   = at91_master_clock;
-                at91_ports[i].ops       = &at91_pops;
-                at91_ports[i].fifosize  = 1;
-                at91_ports[i].line      = i;
-        }
+        if (!at91_port->clk) {          /* for console, the clock could already be configured */
+                at91_port->clk = clk_get(&pdev->dev, "usart");
+                clk_enable(at91_port->clk);
+                port->uartclk = clk_get_rate(at91_port->clk);
+        }
 }
 
-void __init at91_register_uart_fns(struct at91rm9200_port_fns *fns)
+/*
+ * Register board-specific modem-control line handlers.
+ */
+void __init at91_register_uart_fns(struct at91_port_fns *fns)
 {
         if (fns->enable_ms)
                 at91_pops.enable_ms = fns->enable_ms;
@@ -664,51 +724,6 @@ void __init at91_register_uart_fns(struct at91rm9200_port_fns *fns)
         at91_pops.set_wake = fns->set_wake;
 }
 
-/*
- * Setup ports.
- */
-void __init at91_register_uart(int idx, int port)
-{
-        if ((idx < 0) || (idx >= AT91_NR_UART)) {
-                printk(KERN_ERR "%s: bad index number %d\n", __FUNCTION__, idx);
-                return;
-        }
-
-        switch (port) {
-        case 0:
-                at91_ports[idx].membase = (void __iomem *) AT91_VA_BASE_US0;
-                at91_ports[idx].mapbase = AT91_VA_BASE_US0;
-                at91_ports[idx].irq     = AT91_ID_US0;
-                AT91_CfgPIO_USART0();
-                break;
-        case 1:
-                at91_ports[idx].membase = (void __iomem *) AT91_VA_BASE_US1;
-                at91_ports[idx].mapbase = AT91_VA_BASE_US1;
-                at91_ports[idx].irq     = AT91_ID_US1;
-                AT91_CfgPIO_USART1();
-                break;
-        case 2:
-                at91_ports[idx].membase = (void __iomem *) AT91_VA_BASE_US2;
-                at91_ports[idx].mapbase = AT91_VA_BASE_US2;
-                at91_ports[idx].irq     = AT91_ID_US2;
-                AT91_CfgPIO_USART2();
-                break;
-        case 3:
-                at91_ports[idx].membase = (void __iomem *) AT91_VA_BASE_US3;
-                at91_ports[idx].mapbase = AT91_VA_BASE_US3;
-                at91_ports[idx].irq     = AT91_ID_US3;
-                AT91_CfgPIO_USART3();
-                break;
-        case 4:
-                at91_ports[idx].membase = (void __iomem *) AT91_VA_BASE_DBGU;
-                at91_ports[idx].mapbase = AT91_VA_BASE_DBGU;
-                at91_ports[idx].irq     = AT91_ID_SYS;
-                AT91_CfgPIO_DBGU();
-                break;
-        default:
-                printk(KERN_ERR  "%s : bad port number %d\n", __FUNCTION__, port);
-        }
-}
 
 #ifdef CONFIG_SERIAL_AT91_CONSOLE
 static void at91_console_putchar(struct uart_port *port, int ch)
@@ -723,7 +738,7 @@ static void at91_console_putchar(struct uart_port *port, int ch)
  */
 static void at91_console_write(struct console *co, const char *s, u_int count)
 {
-        struct uart_port *port = at91_ports + co->index;
+        struct uart_port *port = &at91_ports[co->index].uart;
         unsigned int status, imr;
 
         /*
@@ -778,23 +793,15 @@ static void __init at91_console_get_options(struct uart_port *port, int *baud, i
 
 static int __init at91_console_setup(struct console *co, char *options)
 {
-        struct uart_port *port;
+        struct uart_port *port = &at91_ports[co->index].uart;
         int baud = 115200;
         int bits = 8;
         int parity = 'n';
         int flow = 'n';
 
-        /*
-         * Check whether an invalid uart number has been specified, and
-         * if so, search for the first available port that does have
-         * console support.
-         */
-        port = uart_get_console(at91_ports, AT91_NR_UART, co);
+        if (port->membase == 0)         /* Port not initialized yet - delay setup */
+                return -ENODEV;
 
-        /*
-         * Enable the serial console, in-case bootloader did not do it.
-         */
-        at91_sys_write(AT91_PMC_PCER, 1 << port->irq);  /* enable clock */
         UART_PUT_IDR(port, -1);                         /* disable interrupts */
         UART_PUT_CR(port, AT91_US_RSTSTA | AT91_US_RSTRX);
         UART_PUT_CR(port, AT91_US_TXEN | AT91_US_RXEN);
@@ -821,23 +828,40 @@ static struct console at91_console = {
 
 #define AT91_CONSOLE_DEVICE     &at91_console
 
-static int  __init at91_console_init(void)
+/*
+ * Early console initialization (before VM subsystem initialized).
+ */
+static int __init at91_console_init(void)
 {
-        at91_init_ports();
+        if (at91_default_console_device) {
+                add_preferred_console(AT91_DEVICENAME, at91_default_console_device->id, NULL);
+                at91_init_port(&(at91_ports[at91_default_console_device->id]), at91_default_console_device);
+                register_console(&at91_console);
+        }
 
-        at91_console.index = at91_console_port;
-        register_console(&at91_console);
         return 0;
 }
 console_initcall(at91_console_init);
 
+/*
+ * Late console initialization.
+ */
+static int __init at91_late_console_init(void)
+{
+        if (at91_default_console_device && !(at91_console.flags & CON_ENABLED))
+                register_console(&at91_console);
+
+        return 0;
+}
+core_initcall(at91_late_console_init);
+
 #else
 #define AT91_CONSOLE_DEVICE     NULL
 #endif
 
 static struct uart_driver at91_uart = {
         .owner                  = THIS_MODULE,
-        .driver_name            = AT91_DEVICENAME,
+        .driver_name            = "at91_serial",
         .dev_name               = AT91_DEVICENAME,
         .devfs_name             = AT91_DEVICENAME,
         .major                  = SERIAL_AT91_MAJOR,
@@ -846,33 +870,106 @@ static struct uart_driver at91_uart = {
         .cons                   = AT91_CONSOLE_DEVICE,
 };
 
-static int __init at91_serial_init(void)
+#ifdef CONFIG_PM
+static int at91_serial_suspend(struct platform_device *pdev, pm_message_t state)
 {
-        int ret, i;
+        struct uart_port *port = platform_get_drvdata(pdev);
+        struct at91_uart_port *at91_port = (struct at91_uart_port *) port;
+
+        if (device_may_wakeup(&pdev->dev) && !at91_suspend_entering_slow_clock())
+                enable_irq_wake(port->irq);
+        else {
+                disable_irq_wake(port->irq);
+                uart_suspend_port(&at91_uart, port);
+                at91_port->suspended = 1;
+        }
 
-        at91_init_ports();
+        return 0;
+}
 
-        ret = uart_register_driver(&at91_uart);
-        if (ret)
-                return ret;
+static int at91_serial_resume(struct platform_device *pdev)
+{
+        struct uart_port *port = platform_get_drvdata(pdev);
+        struct at91_uart_port *at91_port = (struct at91_uart_port *) port;
 
-        for (i = 0; i < AT91_NR_UART; i++) {
-                if (at91_serial_map[i] >= 0)
-                        uart_add_one_port(&at91_uart, &at91_ports[i]);
+        if (at91_port->suspended) {
+                uart_resume_port(&at91_uart, port);
+                at91_port->suspended = 0;
         }
 
         return 0;
 }
+#else
+#define at91_serial_suspend NULL
+#define at91_serial_resume NULL
+#endif
 
-static void __exit at91_serial_exit(void)
+static int __devinit at91_serial_probe(struct platform_device *pdev)
 {
-        int i;
+        struct at91_uart_port *port;
+        int ret;
 
-        for (i = 0; i < AT91_NR_UART; i++) {
-                if (at91_serial_map[i] >= 0)
-                        uart_remove_one_port(&at91_uart, &at91_ports[i]);
-        }
+        port = &at91_ports[pdev->id];
+        at91_init_port(port, pdev);
 
+        ret = uart_add_one_port(&at91_uart, &port->uart);
+        if (!ret) {
+                device_init_wakeup(&pdev->dev, 1);
+                platform_set_drvdata(pdev, port);
+        }
+
+        return ret;
+}
+
+static int __devexit at91_serial_remove(struct platform_device *pdev)
+{
+        struct uart_port *port = platform_get_drvdata(pdev);
+        struct at91_uart_port *at91_port = (struct at91_uart_port *) port;
+        int ret = 0;
+
+        clk_disable(at91_port->clk);
+        clk_put(at91_port->clk);
+
+        device_init_wakeup(&pdev->dev, 0);
+        platform_set_drvdata(pdev, NULL);
+
+        if (port) {
+                ret = uart_remove_one_port(&at91_uart, port);
+                kfree(port);
+        }
+
+        return ret;
+}
+
+static struct platform_driver at91_serial_driver = {
+        .probe          = at91_serial_probe,
+        .remove         = __devexit_p(at91_serial_remove),
+        .suspend        = at91_serial_suspend,
+        .resume         = at91_serial_resume,
+        .driver         = {
+                .name   = "at91_usart",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init at91_serial_init(void)
+{
+        int ret;
+
+        ret = uart_register_driver(&at91_uart);
+        if (ret)
+                return ret;
+
+        ret = platform_driver_register(&at91_serial_driver);
+        if (ret)
+                uart_unregister_driver(&at91_uart);
+
+        return ret;
+}
+
+static void __exit at91_serial_exit(void)
+{
+        platform_driver_unregister(&at91_serial_driver);
         uart_unregister_driver(&at91_uart);
 }