V4L/DVB (11742): TI THS7303 video amplifier driver code
[pandora-kernel.git] / drivers / serial / bfin_5xx.c
index d86123e..e2f6b1b 100644 (file)
@@ -330,6 +330,11 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
                /* Clear TFI bit */
                UART_PUT_LSR(uart, TFI);
 #endif
+               /* Anomaly notes:
+                *  05000215 -  we always clear ETBEI within last UART TX
+                *              interrupt to end a string. It is always set
+                *              when start a new tx.
+                */
                UART_CLEAR_IER(uart, ETBEI);
                return;
        }
@@ -415,6 +420,7 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
        set_dma_start_addr(uart->tx_dma_channel, (unsigned long)(xmit->buf+xmit->tail));
        set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
        set_dma_x_modify(uart->tx_dma_channel, 1);
+       SSYNC();
        enable_dma(uart->tx_dma_channel);
 
        UART_SET_IER(uart, ETBEI);
@@ -473,27 +479,41 @@ 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;
-       unsigned long flags;
-
-       spin_lock_irqsave(&uart->port.lock, flags);
 
+       dma_disable_irq(uart->rx_dma_channel);
+       spin_lock_bh(&uart->port.lock);
+
+       /* 2D DMA RX buffer ring is used. Because curr_y_count and
+        * curr_x_count can't be read as an atomic operation,
+        * curr_y_count should be read before curr_x_count. When
+        * curr_x_count is read, curr_y_count may already indicate
+        * next buffer line. But, the position calculated here is
+        * still indicate the old line. The wrong position data may
+        * be smaller than current buffer tail, which cause garbages
+        * are received if it is not prohibit.
+        */
        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)
+       if (uart->rx_dma_nrows == DMA_RX_YCOUNT || x_pos == 0)
                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) {
+       /* Ignore receiving data if new position is in the same line of
+        * current buffer tail and small.
+        */
+       if (pos > uart->rx_dma_buf.tail ||
+               uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
                uart->rx_dma_buf.head = pos;
                bfin_serial_dma_rx_chars(uart);
                uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
        }
 
-       spin_unlock_irqrestore(&uart->port.lock, flags);
+       spin_unlock_bh(&uart->port.lock);
+       dma_enable_irq(uart->rx_dma_channel);
 
        mod_timer(&(uart->rx_dma_timer), jiffies + DMA_RX_FLUSH_JIFFIES);
 }
@@ -514,6 +534,11 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
        if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
                disable_dma(uart->tx_dma_channel);
                clear_dma_irqstat(uart->tx_dma_channel);
+               /* Anomaly notes:
+                *  05000215 -  we always clear ETBEI within last UART TX
+                *              interrupt to end a string. It is always set
+                *              when start a new tx.
+                */
                UART_CLEAR_IER(uart, ETBEI);
                xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
                uart->port.icount.tx += uart->tx_count;
@@ -532,11 +557,26 @@ static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id)
 {
        struct bfin_serial_port *uart = dev_id;
        unsigned short irqstat;
+       int x_pos, pos;
 
        spin_lock(&uart->port.lock);
        irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
        clear_dma_irqstat(uart->rx_dma_channel);
-       bfin_serial_dma_rx_chars(uart);
+
+       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 || x_pos == 0)
+               uart->rx_dma_nrows = 0;
+
+       pos = uart->rx_dma_nrows * DMA_RX_XCOUNT;
+       if (pos > uart->rx_dma_buf.tail ||
+               uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
+               uart->rx_dma_buf.head = pos;
+               bfin_serial_dma_rx_chars(uart);
+               uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
+       }
+
        spin_unlock(&uart->port.lock);
 
        return IRQ_HANDLED;
@@ -789,8 +829,16 @@ bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
                        __func__);
        }
 
-       if (termios->c_cflag & CSTOPB)
-               lcr |= STB;
+       /* Anomaly notes:
+        *  05000231 -  STOP bit is always set to 1 whatever the user is set.
+        */
+       if (termios->c_cflag & CSTOPB) {
+               if (ANOMALY_05000231)
+                       printk(KERN_WARNING "STOP bits other than 1 is not "
+                               "supported in case of anomaly 05000231.\n");
+               else
+                       lcr |= STB;
+       }
        if (termios->c_cflag & PARENB)
                lcr |= PEN;
        if (!(termios->c_cflag & PARODD))
@@ -940,6 +988,10 @@ static void bfin_serial_reset_irda(struct uart_port *port)
 }
 
 #ifdef CONFIG_CONSOLE_POLL
+/* Anomaly notes:
+ *  05000099 -  Because we only use THRE in poll_put and DR in poll_get,
+ *             losing other bits of UART_LSR is not a problem here.
+ */
 static void bfin_serial_poll_put_char(struct uart_port *port, unsigned char chr)
 {
        struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
@@ -1245,12 +1297,17 @@ static __init void early_serial_write(struct console *con, const char *s,
        }
 }
 
+/*
+ * This should have a .setup or .early_setup in it, but then things get called
+ * without the command line options, and the baud rate gets messed up - so
+ * don't let the common infrastructure play with things. (see calls to setup
+ * & earlysetup in ./kernel/printk.c:register_console()
+ */
 static struct __initdata console bfin_early_serial_console = {
        .name = "early_BFuart",
        .write = early_serial_write,
        .device = uart_console_device,
        .flags = CON_PRINTBUFFER,
-       .setup = bfin_serial_console_setup,
        .index = -1,
        .data  = &bfin_serial_reg,
 };