1 files changed, 15 insertions, 58 deletions

diff --git a/drivers/tty/serial/mfd.c b/drivers/tty/serial/mfd.c
index d40010a22ecd..c111f36f5d21 100644
--- a/drivers/tty/serial/mfd.c
+++ b/drivers/tty/serial/mfd.c
@@ -16,9 +16,7 @@
  *    2/3 chan to port 1, 4/5 chan to port 3. Even number chans
  *    are used for RX, odd chans for TX
  *
- * 2. In A0 stepping, UART will not support TX half empty flag
- *
- * 3. The RI/DSR/DCD/DTR are not pinned out, DCD & DSR are always
+ * 2. The RI/DSR/DCD/DTR are not pinned out, DCD & DSR are always
  *    asserted, only when the HW is reset the DDCD and DDSR will
  *    be triggered
  */
@@ -41,8 +39,6 @@
 #include <linux/io.h>
 #include <linux/debugfs.h>
 
-#define  MFD_HSU_A0_STEPPING	1
-
 #define HSU_DMA_BUF_SIZE	2048
 
 #define chan_readl(chan, offset)	readl(chan->reg + offset)
@@ -51,7 +47,10 @@
 #define mfd_readl(obj, offset)		readl(obj->reg + offset)
 #define mfd_writel(obj, offset, val)	writel(val, obj->reg + offset)
 
-#define HSU_DMA_TIMEOUT_CHECK_FREQ	(HZ/10)
+static int hsu_dma_enable;
+module_param(hsu_dma_enable, int, 0);
+MODULE_PARM_DESC(hsu_dma_enable, "It is a bitmap to set working mode, if \
+bit[x] is 1, then port[x] will work in DMA mode, otherwise in PIO mode.");
 
 struct hsu_dma_buffer {
 	u8		*buf;
@@ -65,7 +64,6 @@ struct hsu_dma_chan {
 	enum dma_data_direction	dirt;
 	struct uart_hsu_port	*uport;
 	void __iomem		*reg;
-	struct timer_list	rx_timer; /* only needed by RX channel */
 };
 
 struct uart_hsu_port {
@@ -355,8 +353,6 @@ void hsu_dma_start_rx_chan(struct hsu_dma_chan *rxc, struct hsu_dma_buffer *dbuf
 					 | (0x1 << 24)	/* timeout bit, see HSU Errata 1 */
 					 );
 	chan_writel(rxc, HSU_CH_CR, 0x3);
-
-	mod_timer(&rxc->rx_timer, jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ);
 }
 
 /* Protected by spin_lock_irqsave(port->lock) */
@@ -420,7 +416,6 @@ void hsu_dma_rx(struct uart_hsu_port *up, u32 int_sts)
 		chan_writel(chan, HSU_CH_CR, 0x3);
 		return;
 	}
-	del_timer(&chan->rx_timer);
 
 	dma_sync_single_for_cpu(port->dev, dbuf->dma_addr,
 			dbuf->dma_size, DMA_FROM_DEVICE);
@@ -448,8 +443,6 @@ void hsu_dma_rx(struct uart_hsu_port *up, u32 int_sts)
 	tty_flip_buffer_push(tty);
 
 	chan_writel(chan, HSU_CH_CR, 0x3);
-	chan->rx_timer.expires = jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ;
-	add_timer(&chan->rx_timer);
 
 }
 
@@ -551,16 +544,9 @@ static void transmit_chars(struct uart_hsu_port *up)
 		return;
 	}
 
-#ifndef MFD_HSU_A0_STEPPING
+	/* The IRQ is for TX FIFO half-empty */
 	count = up->port.fifosize / 2;
-#else
-	/*
-	 * A0 only supports fully empty IRQ, and the first char written
-	 * into it won't clear the EMPT bit, so we may need be cautious
-	 * by useing a shorter buffer
-	 */
-	count = up->port.fifosize - 4;
-#endif
+
 	do {
 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
@@ -769,9 +755,8 @@ static void serial_hsu_break_ctl(struct uart_port *port, int break_state)
 /*
  * What special to do:
  * 1. chose the 64B fifo mode
- * 2. make sure not to select half empty mode for A0 stepping
- * 3. start dma or pio depends on configuration
- * 4. we only allocate dma memory when needed
+ * 2. start dma or pio depends on configuration
+ * 3. we only allocate dma memory when needed
  */
 static int serial_hsu_startup(struct uart_port *port)
 {
@@ -870,8 +855,6 @@ static void serial_hsu_shutdown(struct uart_port *port)
 		container_of(port, struct uart_hsu_port, port);
 	unsigned long flags;
 
-	del_timer_sync(&up->rxc->rx_timer);
-
 	/* Disable interrupts from this port */
 	up->ier = 0;
 	serial_out(up, UART_IER, 0);
@@ -977,10 +960,6 @@ serial_hsu_set_termios(struct uart_port *port, struct ktermios *termios,
 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_32B;
 
 	fcr |= UART_FCR_HSU_64B_FIFO;
-#ifdef MFD_HSU_A0_STEPPING
-	/* A0 doesn't support half empty IRQ */
-	fcr |= UART_FCR_FULL_EMPT_TXI;
-#endif
 
 	/*
 	 * Ok, we're now changing the port state.  Do it with
@@ -1343,28 +1322,6 @@ err_disable:
 	return ret;
 }
 
-static void hsu_dma_rx_timeout(unsigned long data)
-{
-	struct hsu_dma_chan *chan = (void *)data;
-	struct uart_hsu_port *up = chan->uport;
-	struct hsu_dma_buffer *dbuf = &up->rxbuf;
-	int count = 0;
-	unsigned long flags;
-
-	spin_lock_irqsave(&up->port.lock, flags);
-
-	count = chan_readl(chan, HSU_CH_D0SAR) - dbuf->dma_addr;
-
-	if (!count) {
-		mod_timer(&chan->rx_timer, jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ);
-		goto exit;
-	}
-
-	hsu_dma_rx(up, 0);
-exit:
-	spin_unlock_irqrestore(&up->port.lock, flags);
-}
-
 static void hsu_global_init(void)
 {
 	struct hsu_port *hsu;
@@ -1415,6 +1372,12 @@ static void hsu_global_init(void)
 
 		serial_hsu_ports[i] = uport;
 		uport->index = i;
+
+		if (hsu_dma_enable & (1<<i))
+			uport->use_dma = 1;
+		else
+			uport->use_dma = 0;
+
 		uport++;
 	}
 
@@ -1427,12 +1390,6 @@ static void hsu_global_init(void)
 		dchan->reg = hsu->reg + HSU_DMA_CHANS_REG_OFFSET +
 				i * HSU_DMA_CHANS_REG_LENGTH;
 
-		/* Work around for RX */
-		if (dchan->dirt == DMA_FROM_DEVICE) {
-			init_timer(&dchan->rx_timer);
-			dchan->rx_timer.function = hsu_dma_rx_timeout;
-			dchan->rx_timer.data = (unsigned long)dchan;
-		}
 		dchan++;
 	}