1 files changed, 229 insertions, 65 deletions

diff --git a/drivers/serial/imx.c b/drivers/serial/imx.c
index 738c8a5f64f2..285b414f3054 100644
--- a/drivers/serial/imx.c
+++ b/drivers/serial/imx.c
@@ -8,6 +8,9 @@
  *  Author: Sascha Hauer <sascha@saschahauer.de>
  *  Copyright (C) 2004 Pengutronix
  *
+ *  Copyright (C) 2009 emlix GmbH
+ *  Author: Fabian Godehardt (added IrDA support for iMX)
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -41,6 +44,8 @@
 #include <linux/serial_core.h>
 #include <linux/serial.h>
 #include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/rational.h>
 
 #include <asm/io.h>
 #include <asm/irq.h>
@@ -148,6 +153,7 @@
 #define  UCR4_DREN       (1<<0)  /* Recv data ready interrupt enable */
 #define  UFCR_RXTL_SHF   0       /* Receiver trigger level shift */
 #define  UFCR_RFDIV      (7<<7)  /* Reference freq divider mask */
+#define  UFCR_RFDIV_REG(x)      (((x) < 7 ? 6 - (x) : 6) << 7)
 #define  UFCR_TXTL_SHF   10      /* Transmitter trigger level shift */
 #define  USR1_PARITYERR  (1<<15) /* Parity error interrupt flag */
 #define  USR1_RTSS       (1<<14) /* RTS pin status */
@@ -204,10 +210,20 @@ struct imx_port {
         struct timer_list       timer;
         unsigned int            old_status;
         int                     txirq,rxirq,rtsirq;
-        int                     have_rtscts:1;
+        unsigned int            have_rtscts:1;
+        unsigned int            use_irda:1;
+        unsigned int            irda_inv_rx:1;
+        unsigned int            irda_inv_tx:1;
+        unsigned short          trcv_delay; /* transceiver delay */
         struct clk              *clk;
 };
 
+#ifdef CONFIG_IRDA
+#define USE_IRDA(sport) ((sport)->use_irda)
+#else
+#define USE_IRDA(sport) (0)
+#endif
+
 /*
  * Handle any change of modem status signal since we were last called.
  */
@@ -261,6 +277,48 @@ static void imx_stop_tx(struct uart_port *port)
         struct imx_port *sport = (struct imx_port *)port;
         unsigned long temp;
 
+        if (USE_IRDA(sport)) {
+                /* half duplex - wait for end of transmission */
+                int n = 256;
+                while ((--n > 0) &&
+                      !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
+                        udelay(5);
+                        barrier();
+                }
+                /*
+                 * irda transceiver - wait a bit more to avoid
+                 * cutoff, hardware dependent
+                 */
+                udelay(sport->trcv_delay);
+
+                /*
+                 * half duplex - reactivate receive mode,
+                 * flush receive pipe echo crap
+                 */
+                if (readl(sport->port.membase + USR2) & USR2_TXDC) {
+                        temp = readl(sport->port.membase + UCR1);
+                        temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
+                        writel(temp, sport->port.membase + UCR1);
+
+                        temp = readl(sport->port.membase + UCR4);
+                        temp &= ~(UCR4_TCEN);
+                        writel(temp, sport->port.membase + UCR4);
+
+                        while (readl(sport->port.membase + URXD0) &
+                               URXD_CHARRDY)
+                                barrier();
+
+                        temp = readl(sport->port.membase + UCR1);
+                        temp |= UCR1_RRDYEN;
+                        writel(temp, sport->port.membase + UCR1);
+
+                        temp = readl(sport->port.membase + UCR4);
+                        temp |= UCR4_DREN;
+                        writel(temp, sport->port.membase + UCR4);
+                }
+                return;
+        }
+
         temp = readl(sport->port.membase + UCR1);
         writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
 }
@@ -295,13 +353,15 @@ static inline void imx_transmit_buffer(struct imx_port *sport)
                 /* send xmit->buf[xmit->tail]
                  * out the port here */
                 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
-                xmit->tail = (xmit->tail + 1) &
-                         (UART_XMIT_SIZE - 1);
+                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
                 sport->port.icount.tx++;
                 if (uart_circ_empty(xmit))
                         break;
         }
 
+        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+                uart_write_wakeup(&sport->port);
+
         if (uart_circ_empty(xmit))
                 imx_stop_tx(&sport->port);
 }
@@ -314,9 +374,30 @@ static void imx_start_tx(struct uart_port *port)
         struct imx_port *sport = (struct imx_port *)port;
         unsigned long temp;
 
+        if (USE_IRDA(sport)) {
+                /* half duplex in IrDA mode; have to disable receive mode */
+                temp = readl(sport->port.membase + UCR4);
+                temp &= ~(UCR4_DREN);
+                writel(temp, sport->port.membase + UCR4);
+
+                temp = readl(sport->port.membase + UCR1);
+                temp &= ~(UCR1_RRDYEN);
+                writel(temp, sport->port.membase + UCR1);
+        }
+
         temp = readl(sport->port.membase + UCR1);
         writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
 
+        if (USE_IRDA(sport)) {
+                temp = readl(sport->port.membase + UCR1);
+                temp |= UCR1_TRDYEN;
+                writel(temp, sport->port.membase + UCR1);
+
+                temp = readl(sport->port.membase + UCR4);
+                temp |= UCR4_TCEN;
+                writel(temp, sport->port.membase + UCR4);
+        }
+
         if (readl(sport->port.membase + UTS) & UTS_TXEMPTY)
                 imx_transmit_buffer(sport);
 }
@@ -388,8 +469,7 @@ static irqreturn_t imx_rxint(int irq, void *dev_id)
                                 continue;
                 }
 
-                if (uart_handle_sysrq_char
-                            (&sport->port, (unsigned char)rx))
+                if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
                         continue;
 
                 if (rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) ) {
@@ -464,26 +544,26 @@ static unsigned int imx_tx_empty(struct uart_port *port)
  */
 static unsigned int imx_get_mctrl(struct uart_port *port)
 {
-        struct imx_port *sport = (struct imx_port *)port;
-        unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
+        struct imx_port *sport = (struct imx_port *)port;
+        unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
 
-        if (readl(sport->port.membase + USR1) & USR1_RTSS)
-                tmp |= TIOCM_CTS;
+        if (readl(sport->port.membase + USR1) & USR1_RTSS)
+                tmp |= TIOCM_CTS;
 
-        if (readl(sport->port.membase + UCR2) & UCR2_CTS)
-                tmp |= TIOCM_RTS;
+        if (readl(sport->port.membase + UCR2) & UCR2_CTS)
+                tmp |= TIOCM_RTS;
 
-        return tmp;
+        return tmp;
 }
 
 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
-        struct imx_port *sport = (struct imx_port *)port;
+        struct imx_port *sport = (struct imx_port *)port;
         unsigned long temp;
 
         temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
 
-        if (mctrl & TIOCM_RTS)
+        if (mctrl & TIOCM_RTS)
                 temp |= UCR2_CTS;
 
         writel(temp, sport->port.membase + UCR2);
@@ -527,12 +607,7 @@ static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
         if(!ufcr_rfdiv)
                 ufcr_rfdiv = 1;
 
-        if(ufcr_rfdiv >= 7)
-                ufcr_rfdiv = 6;
-        else
-                ufcr_rfdiv = 6 - ufcr_rfdiv;
-
-        val |= UFCR_RFDIV & (ufcr_rfdiv << 7);
+        val |= UFCR_RFDIV_REG(ufcr_rfdiv);
 
         writel(val, sport->port.membase + UFCR);
 
@@ -551,8 +626,24 @@ static int imx_startup(struct uart_port *port)
          * requesting IRQs
          */
         temp = readl(sport->port.membase + UCR4);
+
+        if (USE_IRDA(sport))
+                temp |= UCR4_IRSC;
+
         writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
 
+        if (USE_IRDA(sport)) {
+                /* reset fifo's and state machines */
+                int i = 100;
+                temp = readl(sport->port.membase + UCR2);
+                temp &= ~UCR2_SRST;
+                writel(temp, sport->port.membase + UCR2);
+                while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) &&
+                    (--i > 0)) {
+                        udelay(1);
+                }
+        }
+
         /*
          * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
          * chips only have one interrupt.
@@ -568,12 +659,16 @@ static int imx_startup(struct uart_port *port)
                 if (retval)
                         goto error_out2;
 
-                retval = request_irq(sport->rtsirq, imx_rtsint,
-                             (sport->rtsirq < MAX_INTERNAL_IRQ) ? 0 :
-                               IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
-                                DRIVER_NAME, sport);
-                if (retval)
-                        goto error_out3;
+                /* do not use RTS IRQ on IrDA */
+                if (!USE_IRDA(sport)) {
+                        retval = request_irq(sport->rtsirq, imx_rtsint,
+                                     (sport->rtsirq < MAX_INTERNAL_IRQ) ? 0 :
+                                       IRQF_TRIGGER_FALLING |
+                                       IRQF_TRIGGER_RISING,
+                                        DRIVER_NAME, sport);
+                        if (retval)
+                                goto error_out3;
+                }
         } else {
                 retval = request_irq(sport->port.irq, imx_int, 0,
                                 DRIVER_NAME, sport);
@@ -590,18 +685,49 @@ static int imx_startup(struct uart_port *port)
 
         temp = readl(sport->port.membase + UCR1);
         temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
+
+        if (USE_IRDA(sport)) {
+                temp |= UCR1_IREN;
+                temp &= ~(UCR1_RTSDEN);
+        }
+
         writel(temp, sport->port.membase + UCR1);
 
         temp = readl(sport->port.membase + UCR2);
         temp |= (UCR2_RXEN | UCR2_TXEN);
         writel(temp, sport->port.membase + UCR2);
 
+        if (USE_IRDA(sport)) {
+                /* clear RX-FIFO */
+                int i = 64;
+                while ((--i > 0) &&
+                        (readl(sport->port.membase + URXD0) & URXD_CHARRDY)) {
+                        barrier();
+                }
+        }
+
 #if defined CONFIG_ARCH_MX2 || defined CONFIG_ARCH_MX3
         temp = readl(sport->port.membase + UCR3);
         temp |= UCR3_RXDMUXSEL;
         writel(temp, sport->port.membase + UCR3);
 #endif
 
+        if (USE_IRDA(sport)) {
+                temp = readl(sport->port.membase + UCR4);
+                if (sport->irda_inv_rx)
+                        temp |= UCR4_INVR;
+                else
+                        temp &= ~(UCR4_INVR);
+                writel(temp | UCR4_DREN, sport->port.membase + UCR4);
+
+                temp = readl(sport->port.membase + UCR3);
+                if (sport->irda_inv_tx)
+                        temp |= UCR3_INVT;
+                else
+                        temp &= ~(UCR3_INVT);
+                writel(temp, sport->port.membase + UCR3);
+        }
+
         /*
          * Enable modem status interrupts
          */
@@ -609,6 +735,16 @@ static int imx_startup(struct uart_port *port)
         imx_enable_ms(&sport->port);
         spin_unlock_irqrestore(&sport->port.lock,flags);
 
+        if (USE_IRDA(sport)) {
+                struct imxuart_platform_data *pdata;
+                pdata = sport->port.dev->platform_data;
+                sport->irda_inv_rx = pdata->irda_inv_rx;
+                sport->irda_inv_tx = pdata->irda_inv_tx;
+                sport->trcv_delay = pdata->transceiver_delay;
+                if (pdata->irda_enable)
+                        pdata->irda_enable(1);
+        }
+
         return 0;
 
 error_out3:
@@ -626,6 +762,17 @@ static void imx_shutdown(struct uart_port *port)
         struct imx_port *sport = (struct imx_port *)port;
         unsigned long temp;
 
+        temp = readl(sport->port.membase + UCR2);
+        temp &= ~(UCR2_TXEN);
+        writel(temp, sport->port.membase + UCR2);
+
+        if (USE_IRDA(sport)) {
+                struct imxuart_platform_data *pdata;
+                pdata = sport->port.dev->platform_data;
+                if (pdata->irda_enable)
+                        pdata->irda_enable(0);
+        }
+
         /*
          * Stop our timer.
          */
@@ -635,7 +782,8 @@ static void imx_shutdown(struct uart_port *port)
          * Free the interrupts
          */
         if (sport->txirq > 0) {
-                free_irq(sport->rtsirq, sport);
+                if (!USE_IRDA(sport))
+                        free_irq(sport->rtsirq, sport);
                 free_irq(sport->txirq, sport);
                 free_irq(sport->rxirq, sport);
         } else
@@ -647,6 +795,9 @@ static void imx_shutdown(struct uart_port *port)
 
         temp = readl(sport->port.membase + UCR1);
         temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
+        if (USE_IRDA(sport))
+                temp &= ~(UCR1_IREN);
+
         writel(temp, sport->port.membase + UCR1);
 }
 
@@ -658,7 +809,9 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
         unsigned long flags;
         unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
         unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
-        unsigned int div, num, denom, ufcr;
+        unsigned int div, ufcr;
+        unsigned long num, denom;
+        uint64_t tdiv64;
 
         /*
          * If we don't support modem control lines, don't allow
@@ -754,38 +907,39 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
                         sport->port.membase + UCR2);
         old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
 
-        div = sport->port.uartclk / (baud * 16);
-        if (div > 7)
-                div = 7;
-        if (!div)
+        if (USE_IRDA(sport)) {
+                /*
+                 * use maximum available submodule frequency to
+                 * avoid missing short pulses due to low sampling rate
+                 */
                 div = 1;
-
-        num = baud;
-        denom = port->uartclk / div / 16;
-
-        /* shift num and denom right until they fit into 16 bits */
-        while (num > 0x10000 || denom > 0x10000) {
-                num >>= 1;
-                denom >>= 1;
+        } else {
+                div = sport->port.uartclk / (baud * 16);
+                if (div > 7)
+                        div = 7;
+                if (!div)
+                        div = 1;
         }
-        if (num > 0)
-                num -= 1;
-        if (denom > 0)
-                denom -= 1;
 
-        writel(num, sport->port.membase + UBIR);
-        writel(denom, sport->port.membase + UBMR);
+        rational_best_approximation(16 * div * baud, sport->port.uartclk,
+                1 << 16, 1 << 16, &num, &denom);
 
-        if (div == 7)
-                div = 6; /* 6 in RFDIV means divide by 7 */
-        else
-                div = 6 - div;
+        tdiv64 = sport->port.uartclk;
+        tdiv64 *= num;
+        do_div(tdiv64, denom * 16 * div);
+        tty_encode_baud_rate(sport->port.info->port.tty,
+                (speed_t)tdiv64, (speed_t)tdiv64);
+
+        num -= 1;
+        denom -= 1;
 
         ufcr = readl(sport->port.membase + UFCR);
-        ufcr = (ufcr & (~UFCR_RFDIV)) |
-            (div << 7);
+        ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
         writel(ufcr, sport->port.membase + UFCR);
 
+        writel(num, sport->port.membase + UBIR);
+        writel(denom, sport->port.membase + UBMR);
+
 #ifdef ONEMS
         writel(sport->port.uartclk / div / 1000, sport->port.membase + ONEMS);
 #endif
@@ -1065,22 +1219,22 @@ static struct uart_driver imx_reg = {
 
 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
 {
-        struct imx_port *sport = platform_get_drvdata(dev);
+        struct imx_port *sport = platform_get_drvdata(dev);
 
-        if (sport)
-                uart_suspend_port(&imx_reg, &sport->port);
+        if (sport)
+                uart_suspend_port(&imx_reg, &sport->port);
 
-        return 0;
+        return 0;
 }
 
 static int serial_imx_resume(struct platform_device *dev)
 {
-        struct imx_port *sport = platform_get_drvdata(dev);
+        struct imx_port *sport = platform_get_drvdata(dev);
 
-        if (sport)
-                uart_resume_port(&imx_reg, &sport->port);
+        if (sport)
+                uart_resume_port(&imx_reg, &sport->port);
 
-        return 0;
+        return 0;
 }
 
 static int serial_imx_probe(struct platform_device *pdev)
@@ -1136,19 +1290,29 @@ static int serial_imx_probe(struct platform_device *pdev)
         imx_ports[pdev->id] = sport;
 
         pdata = pdev->dev.platform_data;
-        if(pdata && (pdata->flags & IMXUART_HAVE_RTSCTS))
+        if (pdata && (pdata->flags & IMXUART_HAVE_RTSCTS))
                 sport->have_rtscts = 1;
 
+#ifdef CONFIG_IRDA
+        if (pdata && (pdata->flags & IMXUART_IRDA))
+                sport->use_irda = 1;
+#endif
+
         if (pdata->init) {
                 ret = pdata->init(pdev);
                 if (ret)
                         goto clkput;
         }
 
-        uart_add_one_port(&imx_reg, &sport->port);
+        ret = uart_add_one_port(&imx_reg, &sport->port);
+        if (ret)
+                goto deinit;
         platform_set_drvdata(pdev, &sport->port);
 
         return 0;
+deinit:
+        if (pdata->exit)
+                pdata->exit(pdev);
 clkput:
         clk_put(sport->clk);
         clk_disable(sport->clk);
@@ -1186,13 +1350,13 @@ static int serial_imx_remove(struct platform_device *pdev)
 }
 
 static struct platform_driver serial_imx_driver = {
-        .probe          = serial_imx_probe,
-        .remove         = serial_imx_remove,
+        .probe          = serial_imx_probe,
+        .remove         = serial_imx_remove,
 
         .suspend        = serial_imx_suspend,
         .resume         = serial_imx_resume,
         .driver         = {
-                .name   = "imx-uart",
+                .name   = "imx-uart",
                 .owner  = THIS_MODULE,
         },
 };