1 files changed, 136 insertions, 145 deletions

diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index ac2a3ef28d55..0aa345b9a38b 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -1,30 +1,11 @@
 /*
- * File:         drivers/serial/bfin_5xx.c
- * Based on:     Based on drivers/serial/sa1100.c
- * Author:       Aubrey Li <aubrey.li@analog.com>
+ * Blackfin On-Chip Serial Driver
  *
- * Created:
- * Description:  Driver for blackfin 5xx serial ports
+ * Copyright 2006-2007 Analog Devices Inc.
  *
- * Modified:
- *               Copyright 2006 Analog Devices Inc.
+ * Enter bugs at http://blackfin.uclinux.org/
  *
- * Bugs:         Enter bugs at http://blackfin.uclinux.org/
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see the file COPYING, or write
- * to the Free Software Foundation, Inc.,
- * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ * Licensed under the GPL-2 or later.
  */
 
 #if defined(CONFIG_SERIAL_BFIN_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
@@ -67,14 +48,12 @@
 #define DMA_RX_XCOUNT           512
 #define DMA_RX_YCOUNT           (PAGE_SIZE / DMA_RX_XCOUNT)
 
-#define DMA_RX_FLUSH_JIFFIES    5
+#define DMA_RX_FLUSH_JIFFIES    (HZ / 50)
 
 #ifdef CONFIG_SERIAL_BFIN_DMA
 static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
 #else
-static void bfin_serial_do_work(struct work_struct *work);
 static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
-static void local_put_char(struct bfin_serial_port *uart, char ch);
 #endif
 
 static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
@@ -85,23 +64,26 @@ static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
 static void bfin_serial_stop_tx(struct uart_port *port)
 {
         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+        struct circ_buf *xmit = &uart->port.info->xmit;
+#if !defined(CONFIG_BF54x) && !defined(CONFIG_SERIAL_BFIN_DMA)
+        unsigned short ier;
+#endif
 
         while (!(UART_GET_LSR(uart) & TEMT))
-                continue;
+                cpu_relax();
 
 #ifdef CONFIG_SERIAL_BFIN_DMA
         disable_dma(uart->tx_dma_channel);
+        xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
+        uart->port.icount.tx += uart->tx_count;
+        uart->tx_count = 0;
+        uart->tx_done = 1;
 #else
 #ifdef CONFIG_BF54x
-        /* Waiting for Transmission Finished */
-        while (!(UART_GET_LSR(uart) & TFI))
-                continue;
         /* Clear TFI bit */
         UART_PUT_LSR(uart, TFI);
         UART_CLEAR_IER(uart, ETBEI);
 #else
-        unsigned short ier;
-
         ier = UART_GET_IER(uart);
         ier &= ~ETBEI;
         UART_PUT_IER(uart, ier);
@@ -117,7 +99,8 @@ static void bfin_serial_start_tx(struct uart_port *port)
         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 
 #ifdef CONFIG_SERIAL_BFIN_DMA
-        bfin_serial_dma_tx_chars(uart);
+        if (uart->tx_done)
+                bfin_serial_dma_tx_chars(uart);
 #else
 #ifdef CONFIG_BF54x
         UART_SET_IER(uart, ETBEI);
@@ -209,34 +192,27 @@ int kgdb_get_debug_char(void)
 }
 #endif
 
-#ifdef CONFIG_SERIAL_BFIN_PIO
-static void local_put_char(struct bfin_serial_port *uart, char ch)
-{
-        unsigned short status;
-        int flags = 0;
-
-        spin_lock_irqsave(&uart->port.lock, flags);
-
-        do {
-                status = UART_GET_LSR(uart);
-        } while (!(status & THRE));
-
-        UART_PUT_CHAR(uart, ch);
-        SSYNC();
-
-        spin_unlock_irqrestore(&uart->port.lock, flags);
-}
+#if ANOMALY_05000230 && defined(CONFIG_SERIAL_BFIN_PIO)
+# define UART_GET_ANOMALY_THRESHOLD(uart)    ((uart)->anomaly_threshold)
+# define UART_SET_ANOMALY_THRESHOLD(uart, v) ((uart)->anomaly_threshold = (v))
+#else
+# define UART_GET_ANOMALY_THRESHOLD(uart)    0
+# define UART_SET_ANOMALY_THRESHOLD(uart, v)
+#endif
 
+#ifdef CONFIG_SERIAL_BFIN_PIO
 static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
 {
         struct tty_struct *tty = uart->port.info->tty;
         unsigned int status, ch, flg;
-        static int in_break = 0;
+        static struct timeval anomaly_start = { .tv_sec = 0 };
 #ifdef CONFIG_KGDB_UART
         struct pt_regs *regs = get_irq_regs();
 #endif
 
         status = UART_GET_LSR(uart);
+        UART_CLEAR_LSR(uart);
+
         ch = UART_GET_CHAR(uart);
         uart->port.icount.rx++;
 
@@ -262,28 +238,56 @@ static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
 #endif
 
         if (ANOMALY_05000230) {
-                /* The BF533 family of processors have a nice misbehavior where
-                 * they continuously generate characters for a "single" break.
+                /* The BF533 (and BF561) family of processors have a nice anomaly
+                 * where they continuously generate characters for a "single" break.
                  * We have to basically ignore this flood until the "next" valid
-                 * character comes across.  All other Blackfin families operate
-                 * properly though.
+                 * character comes across.  Due to the nature of the flood, it is
+                 * not possible to reliably catch bytes that are sent too quickly
+                 * after this break.  So application code talking to the Blackfin
+                 * which sends a break signal must allow at least 1.5 character
+                 * times after the end of the break for things to stabilize.  This
+                 * timeout was picked as it must absolutely be larger than 1
+                 * character time +/- some percent.  So 1.5 sounds good.  All other
+                 * Blackfin families operate properly.  Woo.
                  * Note: While Anomaly 05000230 does not directly address this,
                  *       the changes that went in for it also fixed this issue.
+                 *       That anomaly was fixed in 0.5+ silicon.  I like bunnies.
                  */
-                if (in_break) {
-                        if (ch != 0) {
-                                in_break = 0;
-                                ch = UART_GET_CHAR(uart);
-                                if (bfin_revid() < 5)
-                                        return;
-                        } else
-                                return;
+                if (anomaly_start.tv_sec) {
+                        struct timeval curr;
+                        suseconds_t usecs;
+
+                        if ((~ch & (~ch + 1)) & 0xff)
+                                goto known_good_char;
+
+                        do_gettimeofday(&curr);
+                        if (curr.tv_sec - anomaly_start.tv_sec > 1)
+                                goto known_good_char;
+
+                        usecs = 0;
+                        if (curr.tv_sec != anomaly_start.tv_sec)
+                                usecs += USEC_PER_SEC;
+                        usecs += curr.tv_usec - anomaly_start.tv_usec;
+
+                        if (usecs > UART_GET_ANOMALY_THRESHOLD(uart))
+                                goto known_good_char;
+
+                        if (ch)
+                                anomaly_start.tv_sec = 0;
+                        else
+                                anomaly_start = curr;
+
+                        return;
+
+ known_good_char:
+                        anomaly_start.tv_sec = 0;
                 }
         }
 
         if (status & BI) {
                 if (ANOMALY_05000230)
-                        in_break = 1;
+                        if (bfin_revid() < 5)
+                                do_gettimeofday(&anomaly_start);
                 uart->port.icount.brk++;
                 if (uart_handle_break(&uart->port))
                         goto ignore_char;
@@ -324,7 +328,6 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
                 UART_PUT_CHAR(uart, uart->port.x_char);
                 uart->port.icount.tx++;
                 uart->port.x_char = 0;
-                return;
         }
         /*
          * Check the modem control lines before
@@ -337,9 +340,12 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
                 return;
         }
 
-        local_put_char(uart, xmit->buf[xmit->tail]);
-        xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
-        uart->port.icount.tx++;
+        while ((UART_GET_LSR(uart) & THRE) && xmit->tail != xmit->head) {
+                UART_PUT_CHAR(uart, xmit->buf[xmit->tail]);
+                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+                uart->port.icount.tx++;
+                SSYNC();
+        }
 
         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                 uart_write_wakeup(&uart->port);
@@ -352,21 +358,11 @@ static irqreturn_t bfin_serial_rx_int(int irq, void *dev_id)
 {
         struct bfin_serial_port *uart = dev_id;
 
-#ifdef CONFIG_BF54x
-        unsigned short status;
-        spin_lock(&uart->port.lock);
-        status = UART_GET_LSR(uart);
-        while ((UART_GET_IER(uart) & ERBFI) && (status & DR)) {
-                bfin_serial_rx_chars(uart);
-                status = UART_GET_LSR(uart);
-        }
-        spin_unlock(&uart->port.lock);
-#else
         spin_lock(&uart->port.lock);
-        while ((UART_GET_IIR(uart) & IIR_STATUS) == IIR_RX_READY)
+        while (UART_GET_LSR(uart) & DR)
                 bfin_serial_rx_chars(uart);
         spin_unlock(&uart->port.lock);
-#endif
+
         return IRQ_HANDLED;
 }
 
@@ -374,25 +370,16 @@ static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id)
 {
         struct bfin_serial_port *uart = dev_id;
 
-#ifdef CONFIG_BF54x
-        unsigned short status;
         spin_lock(&uart->port.lock);
-        status = UART_GET_LSR(uart);
-        while ((UART_GET_IER(uart) & ETBEI) && (status & THRE)) {
+        if (UART_GET_LSR(uart) & THRE)
                 bfin_serial_tx_chars(uart);
-                status = UART_GET_LSR(uart);
-        }
         spin_unlock(&uart->port.lock);
-#else
-        spin_lock(&uart->port.lock);
-        while ((UART_GET_IIR(uart) & IIR_STATUS) == IIR_TX_READY)
-                bfin_serial_tx_chars(uart);
-        spin_unlock(&uart->port.lock);
-#endif
+
         return IRQ_HANDLED;
 }
+#endif
 
-
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
 static void bfin_serial_do_work(struct work_struct *work)
 {
         struct bfin_serial_port *uart = container_of(work, struct bfin_serial_port, cts_workqueue);
@@ -406,33 +393,27 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
 {
         struct circ_buf *xmit = &uart->port.info->xmit;
         unsigned short ier;
-        int flags = 0;
-
-        if (!uart->tx_done)
-                return;
 
         uart->tx_done = 0;
 
+        if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
+                uart->tx_count = 0;
+                uart->tx_done = 1;
+                return;
+        }
+
         if (uart->port.x_char) {
                 UART_PUT_CHAR(uart, uart->port.x_char);
                 uart->port.icount.tx++;
                 uart->port.x_char = 0;
-                uart->tx_done = 1;
-                return;
         }
+
         /*
          * Check the modem control lines before
          * transmitting anything.
          */
         bfin_serial_mctrl_check(uart);
 
-        if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
-                bfin_serial_stop_tx(&uart->port);
-                uart->tx_done = 1;
-                return;
-        }
-
-        spin_lock_irqsave(&uart->port.lock, flags);
         uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
         if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
                 uart->tx_count = UART_XMIT_SIZE - xmit->tail;
@@ -448,6 +429,7 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
         set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
         set_dma_x_modify(uart->tx_dma_channel, 1);
         enable_dma(uart->tx_dma_channel);
+
 #ifdef CONFIG_BF54x
         UART_SET_IER(uart, ETBEI);
 #else
@@ -455,7 +437,6 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
         ier |= ETBEI;
         UART_PUT_IER(uart, ier);
 #endif
-        spin_unlock_irqrestore(&uart->port.lock, flags);
 }
 
 static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
@@ -464,7 +445,11 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
         int i, flg, status;
 
         status = UART_GET_LSR(uart);
-        uart->port.icount.rx += CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail, UART_XMIT_SIZE);;
+        UART_CLEAR_LSR(uart);
+
+        uart->port.icount.rx +=
+                CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail,
+                UART_XMIT_SIZE);
 
         if (status & BI) {
                 uart->port.icount.brk++;
@@ -490,10 +475,12 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
         else
                 flg = TTY_NORMAL;
 
-        for (i = uart->rx_dma_buf.head; i < uart->rx_dma_buf.tail; i++) {
-                if (uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
-                        goto dma_ignore_char;
-                uart_insert_char(&uart->port, status, OE, uart->rx_dma_buf.buf[i], flg);
+        for (i = uart->rx_dma_buf.tail; i != uart->rx_dma_buf.head; i++) {
+                if (i >= UART_XMIT_SIZE)
+                        i = 0;
+                if (!uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
+                        uart_insert_char(&uart->port, status, OE,
+                                uart->rx_dma_buf.buf[i], flg);
         }
 
  dma_ignore_char:
@@ -503,23 +490,23 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
 void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
 {
         int x_pos, pos;
-        int flags = 0;
-
-        bfin_serial_dma_tx_chars(uart);
 
-        spin_lock_irqsave(&uart->port.lock, flags);
-        x_pos = DMA_RX_XCOUNT - get_dma_curr_xcount(uart->rx_dma_channel);
+        uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
+        x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
+        uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
+        if (uart->rx_dma_nrows == DMA_RX_YCOUNT)
+                uart->rx_dma_nrows = 0;
+        x_pos = DMA_RX_XCOUNT - x_pos;
         if (x_pos == DMA_RX_XCOUNT)
                 x_pos = 0;
 
         pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
-
-        if (pos>uart->rx_dma_buf.tail) {
-                uart->rx_dma_buf.tail = pos;
+        if (pos != uart->rx_dma_buf.tail) {
+                uart->rx_dma_buf.head = pos;
                 bfin_serial_dma_rx_chars(uart);
-                uart->rx_dma_buf.head = uart->rx_dma_buf.tail;
+                uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
         }
-        spin_unlock_irqrestore(&uart->port.lock, flags);
+
         uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
         add_timer(&(uart->rx_dma_timer));
 }
@@ -532,8 +519,8 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
 
         spin_lock(&uart->port.lock);
         if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
-                clear_dma_irqstat(uart->tx_dma_channel);
                 disable_dma(uart->tx_dma_channel);
+                clear_dma_irqstat(uart->tx_dma_channel);
 #ifdef CONFIG_BF54x
                 UART_CLEAR_IER(uart, ETBEI);
 #else
@@ -541,15 +528,13 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
                 ier &= ~ETBEI;
                 UART_PUT_IER(uart, ier);
 #endif
-                xmit->tail = (xmit->tail+uart->tx_count) &(UART_XMIT_SIZE -1);
-                uart->port.icount.tx+=uart->tx_count;
+                xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
+                uart->port.icount.tx += uart->tx_count;
 
                 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                         uart_write_wakeup(&uart->port);
 
-                if (uart_circ_empty(xmit))
-                        bfin_serial_stop_tx(&uart->port);
-                uart->tx_done = 1;
+                bfin_serial_dma_tx_chars(uart);
         }
 
         spin_unlock(&uart->port.lock);
@@ -561,18 +546,15 @@ static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id)
         struct bfin_serial_port *uart = dev_id;
         unsigned short irqstat;
 
-        uart->rx_dma_nrows++;
-        if (uart->rx_dma_nrows == DMA_RX_YCOUNT) {
-                uart->rx_dma_nrows = 0;
-                uart->rx_dma_buf.tail = DMA_RX_XCOUNT*DMA_RX_YCOUNT;
-                bfin_serial_dma_rx_chars(uart);
-                uart->rx_dma_buf.head = uart->rx_dma_buf.tail = 0;
-        }
         spin_lock(&uart->port.lock);
         irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
         clear_dma_irqstat(uart->rx_dma_channel);
-
         spin_unlock(&uart->port.lock);
+
+        del_timer(&(uart->rx_dma_timer));
+        uart->rx_dma_timer.expires = jiffies;
+        add_timer(&(uart->rx_dma_timer));
+
         return IRQ_HANDLED;
 }
 #endif
@@ -599,7 +581,11 @@ static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
         if (uart->cts_pin < 0)
                 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 
+# ifdef BF54x
+        if (UART_GET_MSR(uart) & CTS)
+# else
         if (gpio_get_value(uart->cts_pin))
+# endif
                 return TIOCM_DSR | TIOCM_CAR;
         else
 #endif
@@ -614,9 +600,17 @@ static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
                 return;
 
         if (mctrl & TIOCM_RTS)
+# ifdef BF54x
+                UART_PUT_MCR(uart, UART_GET_MCR(uart) & ~MRTS);
+# else
                 gpio_set_value(uart->rts_pin, 0);
+# endif
         else
+# ifdef BF54x
+                UART_PUT_MCR(uart, UART_GET_MCR(uart) | MRTS);
+# else
                 gpio_set_value(uart->rts_pin, 1);
+# endif
 #endif
 }
 
@@ -627,22 +621,17 @@ static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
 {
 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
         unsigned int status;
-# ifdef CONFIG_SERIAL_BFIN_DMA
         struct uart_info *info = uart->port.info;
         struct tty_struct *tty = info->tty;
 
         status = bfin_serial_get_mctrl(&uart->port);
+        uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
         if (!(status & TIOCM_CTS)) {
                 tty->hw_stopped = 1;
+                schedule_work(&uart->cts_workqueue);
         } else {
                 tty->hw_stopped = 0;
         }
-# else
-        status = bfin_serial_get_mctrl(&uart->port);
-        uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
-        if (!(status & TIOCM_CTS))
-                schedule_work(&uart->cts_workqueue);
-# endif
 #endif
 }
 
@@ -743,6 +732,7 @@ static void bfin_serial_shutdown(struct uart_port *port)
         disable_dma(uart->rx_dma_channel);
         free_dma(uart->rx_dma_channel);
         del_timer(&(uart->rx_dma_timer));
+        dma_free_coherent(NULL, PAGE_SIZE, uart->rx_dma_buf.buf, 0);
 #else
 #ifdef  CONFIG_KGDB_UART
         if (uart->port.line != CONFIG_KGDB_UART_PORT)
@@ -814,6 +804,8 @@ bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
         quot = uart_get_divisor(port, baud);
         spin_lock_irqsave(&uart->port.lock, flags);
 
+        UART_SET_ANOMALY_THRESHOLD(uart, USEC_PER_SEC / baud * 15);
+
         do {
                 lsr = UART_GET_LSR(uart);
         } while (!(lsr & TEMT));
@@ -956,10 +948,9 @@ static void __init bfin_serial_init_ports(void)
                 bfin_serial_ports[i].rx_dma_channel =
                         bfin_serial_resource[i].uart_rx_dma_channel;
                 init_timer(&(bfin_serial_ports[i].rx_dma_timer));
-#else
-                INIT_WORK(&bfin_serial_ports[i].cts_workqueue, bfin_serial_do_work);
 #endif
 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
+                INIT_WORK(&bfin_serial_ports[i].cts_workqueue, bfin_serial_do_work);
                 bfin_serial_ports[i].cts_pin        =
                         bfin_serial_resource[i].uart_cts_pin;
                 bfin_serial_ports[i].rts_pin        =