Further serial driver bits

1,488 lines not on this page · raw message

index f10db6e..9aca34b 100644
@@ -186,6 +186,9 @@
 #define PORT_ALTERA_JTAGUART	91
 #define PORT_ALTERA_UART	92
 
+/* High Speed UART for Medfield */
+#define PORT_MFD	93
+
 #ifdef __KERNEL__
 
 #include <linux/compiler.h>

47 lines not on this page · raw message

index cf9327c..c7a0ce1 100644
@@ -221,8 +221,24 @@
 #define UART_FCR_PXAR16	0x80	/* receive FIFO threshold = 16 */
 #define UART_FCR_PXAR32	0xc0	/* receive FIFO threshold = 32 */
 
+/*
+ * Intel MID on-chip HSU (High Speed UART) defined bits
+ */
+#define UART_FCR_HSU_64_1B	0x00	/* receive FIFO treshold = 1 */
+#define UART_FCR_HSU_64_16B	0x40	/* receive FIFO treshold = 16 */
+#define UART_FCR_HSU_64_32B	0x80	/* receive FIFO treshold = 32 */
+#define UART_FCR_HSU_64_56B	0xc0	/* receive FIFO treshold = 56 */
+
+#define UART_FCR_HSU_16_1B	0x00	/* receive FIFO treshold = 1 */
+#define UART_FCR_HSU_16_4B	0x40	/* receive FIFO treshold = 4 */
+#define UART_FCR_HSU_16_8B	0x80	/* receive FIFO treshold = 8 */
+#define UART_FCR_HSU_16_14B	0xc0	/* receive FIFO treshold = 14 */
 
+#define UART_FCR_HSU_64B_FIFO	0x20	/* chose 64 bytes FIFO */
+#define UART_FCR_HSU_16B_FIFO	0x00	/* chose 16 bytes FIFO */
 
+#define UART_FCR_HALF_EMPT_TXI	0x00	/* trigger TX_EMPT IRQ for half empty */
+#define UART_FCR_FULL_EMPT_TXI	0x08	/* trigger TX_EMPT IRQ for full empty */
 
 /*
  * These register definitions are for the 16C950

index 577df02..cf396b6 100644
@@ -64,6 +64,8 @@
 #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)
+
 struct hsu_dma_buffer {
 	u8		*buf;
 	dma_addr_t	dma_addr;

@@ -75,7 +77,8 @@ struct hsu_dma_chan {
 	u32	id;
 	u32	dirt;	/* to or from device */
 	struct uart_hsu_port	*uport;
-	void __iomem	*reg;
+	void __iomem		*reg;
+	struct timer_list	rx_timer; /* only needed by RX channel */
 };
 
 struct uart_hsu_port {

@@ -377,6 +380,8 @@ 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) */

@@ -437,8 +442,13 @@ void hsu_dma_rx(struct uart_hsu_port *up, u32 int_sts)
 	/* We can use 2 ways to calc the actual transfer len */
 	count = chan_readl(chan, HSU_CH_D0SAR) - dbuf->dma_addr;
 
-	if (!count)
+	if (!count) {
+		/* restart the channel before we leave */
+		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);

@@ -463,9 +473,12 @@ void hsu_dma_rx(struct uart_hsu_port *up, u32 int_sts)
 					 | (0x1 << 16)
 					 | (0x1 << 24)	/* timeout bit, see HSU Errata 1 */
 					 );
+	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);
 
-	tty_flip_buffer_push(tty);
 }
 
 static void serial_hsu_stop_rx(struct uart_port *port)

@@ -893,6 +906,8 @@ 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);

@@ -1348,6 +1363,28 @@ 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;

@@ -1409,6 +1446,13 @@ static void hsu_global_init(void)
 		dchan->uport = &hsu->port[i/2];
 		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++;
 	}
 

index f9c01ae..0341853 100644
@@ -56,8 +56,7 @@ struct uart_max3110 {
 	wait_queue_head_t wq;
 	struct task_struct *main_thread;
 	struct task_struct *read_thread;
-	int mthread_up;
-	spinlock_t lock;
+	struct mutex thread_mutex;;
 
 	u32 baud;
 	u16 cur_conf;

@@ -397,7 +396,8 @@ static int max3110_main_thread(void *_max)
 					       atomic_read(&max->con_tx_need) ||
 					     atomic_read(&max->uart_tx_need)) ||
 					     kthread_should_stop());
-		max->mthread_up = 1;
+
+		mutex_lock(&max->thread_mutex);
 
 #ifdef CONFIG_MRST_MAX3110_IRQ
 		if (atomic_read(&max->irq_pending)) {

@@ -417,7 +417,7 @@ static int max3110_main_thread(void *_max)
 			transmit_char(max);
 			atomic_set(&max->uart_tx_need, 0);
 		}
-		max->mthread_up = 0;
+		mutex_unlock(&max->thread_mutex);
 	} while (!kthread_should_stop());
 
 	return ret;

@@ -444,8 +444,9 @@ static int max3110_read_thread(void *_max)
 
 	pr_info(PR_FMT "start read thread\n");
 	do {
-		if (!max->mthread_up)
-			max3110_console_receive(max);
+		mutex_lock(&max->thread_mutex);
+		max3110_console_receive(max);
+		mutex_unlock(&max->thread_mutex);
 
 		set_current_state(TASK_INTERRUPTIBLE);
 		schedule_timeout(HZ / 20);

@@ -745,7 +746,7 @@ static int serial_m3110_probe(struct spi_device *spi)
 	max->name = spi->modalias;	/* use spi name as the name */
 	max->irq = (u16)spi->irq;
 
-	spin_lock_init(&max->lock);
+	mutex_init(&max->thread_mutex);
 
 	max->word_7bits = 0;
 	max->parity = 0;

index 0341853..f6ad1ec 100644
@@ -48,6 +48,10 @@
 
 #define PR_FMT	"mrst_max3110: "
 
+#define UART_TX_NEEDED 1
+#define CON_TX_NEEDED  2
+#define BIT_IRQ_PENDING    3
+
 struct uart_max3110 {
 	struct uart_port port;
 	struct spi_device *spi;

@@ -63,15 +67,13 @@ struct uart_max3110 {
 	u8 clock;
 	u8 parity, word_7bits;
 
-	atomic_t uart_tx_need;
+	unsigned long uart_flags;
 
 	/* console related */
 	struct circ_buf con_xmit;
-	atomic_t con_tx_need;
 
 	/* irq related */
 	u16 irq;
-	atomic_t irq_pending;
 };
 
 /* global data structure, may need be removed */

@@ -176,10 +178,9 @@ static void serial_m3110_con_putchar(struct uart_port *port, int ch)
 		xmit->head = (xmit->head + 1) & (PAGE_SIZE - 1);
 	}
 
-	if (!atomic_read(&max->con_tx_need)) {
-		atomic_set(&max->con_tx_need, 1);
+
+	if (!test_and_set_bit(CON_TX_NEEDED, &max->uart_flags))
 		wake_up_process(max->main_thread);
-	}
 }
 
 /*

@@ -318,10 +319,8 @@ static void serial_m3110_start_tx(struct uart_port *port)
 	struct uart_max3110 *max =
 		container_of(port, struct uart_max3110, port);
 
-	if (!atomic_read(&max->uart_tx_need)) {
-		atomic_set(&max->uart_tx_need, 1);
+	if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags))
 		wake_up_process(max->main_thread);
-	}
 }
 
 static void receive_chars(struct uart_max3110 *max, unsigned char *str, int len)

@@ -392,32 +391,23 @@ static int max3110_main_thread(void *_max)
 	pr_info(PR_FMT "start main thread\n");
 
 	do {
-		wait_event_interruptible(*wq, (atomic_read(&max->irq_pending) ||
-					       atomic_read(&max->con_tx_need) ||
-					     atomic_read(&max->uart_tx_need)) ||
-					     kthread_should_stop());
+		wait_event_interruptible(*wq, max->uart_flags || kthread_should_stop());
 
 		mutex_lock(&max->thread_mutex);
 
-#ifdef CONFIG_MRST_MAX3110_IRQ
-		if (atomic_read(&max->irq_pending)) {
+		if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
 			max3110_console_receive(max);
-			atomic_set(&max->irq_pending, 0);
-		}
-#endif
 
 		/* first handle console output */
-		if (atomic_read(&max->con_tx_need)) {
+		if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
 			send_circ_buf(max, xmit);
-			atomic_set(&max->con_tx_need, 0);
-		}
 
 		/* handle uart output */
-		if (atomic_read(&max->uart_tx_need)) {
+		if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags))
 			transmit_char(max);
-			atomic_set(&max->uart_tx_need, 0);
-		}
+
 		mutex_unlock(&max->thread_mutex);
+
 	} while (!kthread_should_stop());
 
 	return ret;

@@ -430,10 +420,9 @@ static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
 
 	/* max3110's irq is a falling edge, not level triggered,
 	 * so no need to disable the irq */
-	if (!atomic_read(&max->irq_pending)) {
-		atomic_inc(&max->irq_pending);
+	if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
 		wake_up_process(max->main_thread);
-	}
+
 	return IRQ_HANDLED;
 }
 #else

@@ -753,7 +742,8 @@ static int serial_m3110_probe(struct spi_device *spi)
 	max->baud = 0;
 
 	max->cur_conf = 0;
-	atomic_set(&max->irq_pending, 0);
+	max->uart_flags = 0;
+
 	/* Check if reading configuration register returns something sane */
 
 	res = RC_TAG;