From f4b1f03b826ba22c9835e9e89a1ca03541313e04 Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Fri, 16 Nov 2012 16:03:52 +0800 Subject: serial: mxs-auart: distinguish the different SOCs The current mxs-auart driver is used for both mx23 and mx28. But in mx23, the DMA has a bug(see errata:2836). We can not add the DMA support in mx23, but we can add DMA support to auart in mx28. So in order to add the DMA support for the auart in mx28, we should distinguish the distinguish SOCs. This patch adds a new platform_device_id table and a inline function is_imx28_auart() to distinguish the mx23 and mx28. Signed-off-by: Huang Shijie Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 42 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 36 insertions(+), 6 deletions(-) (limited to 'drivers/tty/serial/mxs-auart.c') diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 6db3baa39a97..06d72713fb9c 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -114,11 +114,17 @@ static struct uart_driver auart_driver; +enum mxs_auart_type { + IMX23_AUART, + IMX28_AUART, +}; + struct mxs_auart_port { struct uart_port port; unsigned int flags; unsigned int ctrl; + enum mxs_auart_type devtype; unsigned int irq; @@ -126,6 +132,29 @@ struct mxs_auart_port { struct device *dev; }; +static struct platform_device_id mxs_auart_devtype[] = { + { .name = "mxs-auart-imx23", .driver_data = IMX23_AUART }, + { .name = "mxs-auart-imx28", .driver_data = IMX28_AUART }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(platform, mxs_auart_devtype); + +static struct of_device_id mxs_auart_dt_ids[] = { + { + .compatible = "fsl,imx28-auart", + .data = &mxs_auart_devtype[IMX28_AUART] + }, { + .compatible = "fsl,imx23-auart", + .data = &mxs_auart_devtype[IMX23_AUART] + }, { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mxs_auart_dt_ids); + +static inline int is_imx28_auart(struct mxs_auart_port *s) +{ + return s->devtype == IMX28_AUART; +} + static void mxs_auart_stop_tx(struct uart_port *u); #define to_auart_port(u) container_of(u, struct mxs_auart_port, port) @@ -706,6 +735,8 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s, static int __devinit mxs_auart_probe(struct platform_device *pdev) { + const struct of_device_id *of_id = + of_match_device(mxs_auart_dt_ids, &pdev->dev); struct mxs_auart_port *s; u32 version; int ret = 0; @@ -730,6 +761,11 @@ static int __devinit mxs_auart_probe(struct platform_device *pdev) goto out_free; } + if (of_id) { + pdev->id_entry = of_id->data; + s->devtype = pdev->id_entry->driver_data; + } + s->clk = clk_get(&pdev->dev, NULL); if (IS_ERR(s->clk)) { ret = PTR_ERR(s->clk); @@ -805,12 +841,6 @@ static int __devexit mxs_auart_remove(struct platform_device *pdev) return 0; } -static struct of_device_id mxs_auart_dt_ids[] = { - { .compatible = "fsl,imx23-auart", }, - { /* sentinel */ } -}; -MODULE_DEVICE_TABLE(of, mxs_auart_dt_ids); - static struct platform_driver mxs_auart_driver = { .probe = mxs_auart_probe, .remove = __devexit_p(mxs_auart_remove), -- cgit v1.2.1 From e8001632816e600ced7d9d4790930fd87935c654 Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Fri, 16 Nov 2012 16:03:53 +0800 Subject: serial: mxs-auart: add the DMA support for mx28 Only we meet the following conditions, we can enable the DMA support for auart: (1) We enable the DMA support in the dts file, such as arch/arm/boot/dts/imx28.dtsi. (2) We enable the hardware flow control. (3) We use the mx28, not the mx23. Due to hardware bug(see errata: 2836), we can not add the DMA support to mx23. Signed-off-by: Huang Shijie Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 322 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 317 insertions(+), 5 deletions(-) (limited to 'drivers/tty/serial/mxs-auart.c') diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 06d72713fb9c..d5b9e3039013 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -34,6 +34,8 @@ #include #include #include +#include +#include #include @@ -71,6 +73,15 @@ #define AUART_CTRL0_SFTRST (1 << 31) #define AUART_CTRL0_CLKGATE (1 << 30) +#define AUART_CTRL0_RXTO_ENABLE (1 << 27) +#define AUART_CTRL0_RXTIMEOUT(v) (((v) & 0x7ff) << 16) +#define AUART_CTRL0_XFER_COUNT(v) ((v) & 0xffff) + +#define AUART_CTRL1_XFER_COUNT(v) ((v) & 0xffff) + +#define AUART_CTRL2_DMAONERR (1 << 26) +#define AUART_CTRL2_TXDMAE (1 << 25) +#define AUART_CTRL2_RXDMAE (1 << 24) #define AUART_CTRL2_CTSEN (1 << 15) #define AUART_CTRL2_RTSEN (1 << 14) @@ -111,6 +122,7 @@ #define AUART_STAT_BERR (1 << 18) #define AUART_STAT_PERR (1 << 17) #define AUART_STAT_FERR (1 << 16) +#define AUART_STAT_RXCOUNT_MASK 0xffff static struct uart_driver auart_driver; @@ -122,7 +134,11 @@ enum mxs_auart_type { struct mxs_auart_port { struct uart_port port; - unsigned int flags; +#define MXS_AUART_DMA_CONFIG 0x1 +#define MXS_AUART_DMA_ENABLED 0x2 +#define MXS_AUART_DMA_TX_SYNC 2 /* bit 2 */ +#define MXS_AUART_DMA_RX_READY 3 /* bit 3 */ + unsigned long flags; unsigned int ctrl; enum mxs_auart_type devtype; @@ -130,6 +146,20 @@ struct mxs_auart_port { struct clk *clk; struct device *dev; + + /* for DMA */ + struct mxs_dma_data dma_data; + int dma_channel_rx, dma_channel_tx; + int dma_irq_rx, dma_irq_tx; + int dma_channel; + + struct scatterlist tx_sgl; + struct dma_chan *tx_dma_chan; + void *tx_dma_buf; + + struct scatterlist rx_sgl; + struct dma_chan *rx_dma_chan; + void *rx_dma_buf; }; static struct platform_device_id mxs_auart_devtype[] = { @@ -155,14 +185,107 @@ static inline int is_imx28_auart(struct mxs_auart_port *s) return s->devtype == IMX28_AUART; } +static inline bool auart_dma_enabled(struct mxs_auart_port *s) +{ + return s->flags & MXS_AUART_DMA_ENABLED; +} + static void mxs_auart_stop_tx(struct uart_port *u); #define to_auart_port(u) container_of(u, struct mxs_auart_port, port) -static inline void mxs_auart_tx_chars(struct mxs_auart_port *s) +static void mxs_auart_tx_chars(struct mxs_auart_port *s); + +static void dma_tx_callback(void *param) { + struct mxs_auart_port *s = param; struct circ_buf *xmit = &s->port.state->xmit; + dma_unmap_sg(s->dev, &s->tx_sgl, 1, DMA_TO_DEVICE); + + /* clear the bit used to serialize the DMA tx. */ + clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags); + smp_mb__after_clear_bit(); + + /* wake up the possible processes. */ + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&s->port); + + mxs_auart_tx_chars(s); +} + +static int mxs_auart_dma_tx(struct mxs_auart_port *s, int size) +{ + struct dma_async_tx_descriptor *desc; + struct scatterlist *sgl = &s->tx_sgl; + struct dma_chan *channel = s->tx_dma_chan; + u32 pio; + + /* [1] : send PIO. Note, the first pio word is CTRL1. */ + pio = AUART_CTRL1_XFER_COUNT(size); + desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)&pio, + 1, DMA_TRANS_NONE, 0); + if (!desc) { + dev_err(s->dev, "step 1 error\n"); + return -EINVAL; + } + + /* [2] : set DMA buffer. */ + sg_init_one(sgl, s->tx_dma_buf, size); + dma_map_sg(s->dev, sgl, 1, DMA_TO_DEVICE); + desc = dmaengine_prep_slave_sg(channel, sgl, + 1, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + dev_err(s->dev, "step 2 error\n"); + return -EINVAL; + } + + /* [3] : submit the DMA */ + desc->callback = dma_tx_callback; + desc->callback_param = s; + dmaengine_submit(desc); + dma_async_issue_pending(channel); + return 0; +} + +static void mxs_auart_tx_chars(struct mxs_auart_port *s) +{ + struct circ_buf *xmit = &s->port.state->xmit; + + if (auart_dma_enabled(s)) { + int i = 0; + int size; + void *buffer = s->tx_dma_buf; + + if (test_and_set_bit(MXS_AUART_DMA_TX_SYNC, &s->flags)) + return; + + while (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) { + size = min_t(u32, UART_XMIT_SIZE - i, + CIRC_CNT_TO_END(xmit->head, + xmit->tail, + UART_XMIT_SIZE)); + memcpy(buffer + i, xmit->buf + xmit->tail, size); + xmit->tail = (xmit->tail + size) & (UART_XMIT_SIZE - 1); + + i += size; + if (i >= UART_XMIT_SIZE) + break; + } + + if (uart_tx_stopped(&s->port)) + mxs_auart_stop_tx(&s->port); + + if (i) { + mxs_auart_dma_tx(s, i); + } else { + clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags); + smp_mb__after_clear_bit(); + } + return; + } + + while (!(readl(s->port.membase + AUART_STAT) & AUART_STAT_TXFF)) { if (s->port.x_char) { @@ -316,10 +439,157 @@ static u32 mxs_auart_get_mctrl(struct uart_port *u) return mctrl; } +static bool mxs_auart_dma_filter(struct dma_chan *chan, void *param) +{ + struct mxs_auart_port *s = param; + + if (!mxs_dma_is_apbx(chan)) + return false; + + if (s->dma_channel == chan->chan_id) { + chan->private = &s->dma_data; + return true; + } + return false; +} + +static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s); +static void dma_rx_callback(void *arg) +{ + struct mxs_auart_port *s = (struct mxs_auart_port *) arg; + struct tty_struct *tty = s->port.state->port.tty; + int count; + u32 stat; + + stat = readl(s->port.membase + AUART_STAT); + stat &= ~(AUART_STAT_OERR | AUART_STAT_BERR | + AUART_STAT_PERR | AUART_STAT_FERR); + + count = stat & AUART_STAT_RXCOUNT_MASK; + tty_insert_flip_string(tty, s->rx_dma_buf, count); + + writel(stat, s->port.membase + AUART_STAT); + tty_flip_buffer_push(tty); + + /* start the next DMA for RX. */ + mxs_auart_dma_prep_rx(s); +} + +static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s) +{ + struct dma_async_tx_descriptor *desc; + struct scatterlist *sgl = &s->rx_sgl; + struct dma_chan *channel = s->rx_dma_chan; + u32 pio[1]; + + /* [1] : send PIO */ + pio[0] = AUART_CTRL0_RXTO_ENABLE + | AUART_CTRL0_RXTIMEOUT(0x80) + | AUART_CTRL0_XFER_COUNT(UART_XMIT_SIZE); + desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)pio, + 1, DMA_TRANS_NONE, 0); + if (!desc) { + dev_err(s->dev, "step 1 error\n"); + return -EINVAL; + } + + /* [2] : send DMA request */ + sg_init_one(sgl, s->rx_dma_buf, UART_XMIT_SIZE); + dma_map_sg(s->dev, sgl, 1, DMA_FROM_DEVICE); + desc = dmaengine_prep_slave_sg(channel, sgl, 1, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + dev_err(s->dev, "step 2 error\n"); + return -1; + } + + /* [3] : submit the DMA, but do not issue it. */ + desc->callback = dma_rx_callback; + desc->callback_param = s; + dmaengine_submit(desc); + dma_async_issue_pending(channel); + return 0; +} + +static void mxs_auart_dma_exit_channel(struct mxs_auart_port *s) +{ + if (s->tx_dma_chan) { + dma_release_channel(s->tx_dma_chan); + s->tx_dma_chan = NULL; + } + if (s->rx_dma_chan) { + dma_release_channel(s->rx_dma_chan); + s->rx_dma_chan = NULL; + } + + kfree(s->tx_dma_buf); + kfree(s->rx_dma_buf); + s->tx_dma_buf = NULL; + s->rx_dma_buf = NULL; +} + +static void mxs_auart_dma_exit(struct mxs_auart_port *s) +{ + + writel(AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE | AUART_CTRL2_DMAONERR, + s->port.membase + AUART_CTRL2_CLR); + + mxs_auart_dma_exit_channel(s); + s->flags &= ~MXS_AUART_DMA_ENABLED; + clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags); + clear_bit(MXS_AUART_DMA_RX_READY, &s->flags); +} + +static int mxs_auart_dma_init(struct mxs_auart_port *s) +{ + dma_cap_mask_t mask; + + if (auart_dma_enabled(s)) + return 0; + + /* We do not get the right DMA channels. */ + if (s->dma_channel_rx == -1 || s->dma_channel_rx == -1) + return -EINVAL; + + /* init for RX */ + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + s->dma_channel = s->dma_channel_rx; + s->dma_data.chan_irq = s->dma_irq_rx; + s->rx_dma_chan = dma_request_channel(mask, mxs_auart_dma_filter, s); + if (!s->rx_dma_chan) + goto err_out; + s->rx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA); + if (!s->rx_dma_buf) + goto err_out; + + /* init for TX */ + s->dma_channel = s->dma_channel_tx; + s->dma_data.chan_irq = s->dma_irq_tx; + s->tx_dma_chan = dma_request_channel(mask, mxs_auart_dma_filter, s); + if (!s->tx_dma_chan) + goto err_out; + s->tx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA); + if (!s->tx_dma_buf) + goto err_out; + + /* set the flags */ + s->flags |= MXS_AUART_DMA_ENABLED; + dev_dbg(s->dev, "enabled the DMA support."); + + return 0; + +err_out: + mxs_auart_dma_exit_channel(s); + return -EINVAL; + +} + static void mxs_auart_settermios(struct uart_port *u, struct ktermios *termios, struct ktermios *old) { + struct mxs_auart_port *s = to_auart_port(u); u32 bm, ctrl, ctrl2, div; unsigned int cflag, baud; @@ -391,10 +661,23 @@ static void mxs_auart_settermios(struct uart_port *u, ctrl |= AUART_LINECTRL_STP2; /* figure out the hardware flow control settings */ - if (cflag & CRTSCTS) + if (cflag & CRTSCTS) { + /* + * The DMA has a bug(see errata:2836) in mx23. + * So we can not implement the DMA for auart in mx23, + * we can only implement the DMA support for auart + * in mx28. + */ + if (is_imx28_auart(s) && (s->flags & MXS_AUART_DMA_CONFIG)) { + if (!mxs_auart_dma_init(s)) + /* enable DMA tranfer */ + ctrl2 |= AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE + | AUART_CTRL2_DMAONERR; + } ctrl2 |= AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN; - else + } else { ctrl2 &= ~(AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN); + } /* set baud rate */ baud = uart_get_baud_rate(u, termios, old, 0, u->uartclk); @@ -406,6 +689,18 @@ static void mxs_auart_settermios(struct uart_port *u, writel(ctrl2, u->membase + AUART_CTRL2); uart_update_timeout(u, termios->c_cflag, baud); + + /* prepare for the DMA RX. */ + if (auart_dma_enabled(s) && + !test_and_set_bit(MXS_AUART_DMA_RX_READY, &s->flags)) { + if (!mxs_auart_dma_prep_rx(s)) { + /* Disable the normal RX interrupt. */ + writel(AUART_INTR_RXIEN, u->membase + AUART_INTR_CLR); + } else { + mxs_auart_dma_exit(s); + dev_err(s->dev, "We can not start up the DMA.\n"); + } + } } static irqreturn_t mxs_auart_irq_handle(int irq, void *context) @@ -484,6 +779,9 @@ static void mxs_auart_shutdown(struct uart_port *u) { struct mxs_auart_port *s = to_auart_port(u); + if (auart_dma_enabled(s)) + mxs_auart_dma_exit(s); + writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_CLR); writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN, @@ -717,6 +1015,7 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s, struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; + u32 dma_channel[2]; int ret; if (!np) @@ -730,6 +1029,20 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s, } s->port.line = ret; + s->dma_irq_rx = platform_get_irq(pdev, 1); + s->dma_irq_tx = platform_get_irq(pdev, 2); + + ret = of_property_read_u32_array(np, "fsl,auart-dma-channel", + dma_channel, 2); + if (ret == 0) { + s->dma_channel_rx = dma_channel[0]; + s->dma_channel_tx = dma_channel[1]; + + s->flags |= MXS_AUART_DMA_CONFIG; + } else { + s->dma_channel_rx = -1; + s->dma_channel_tx = -1; + } return 0; } @@ -787,7 +1100,6 @@ static int __devinit mxs_auart_probe(struct platform_device *pdev) s->port.type = PORT_IMX; s->port.dev = s->dev = get_device(&pdev->dev); - s->flags = 0; s->ctrl = 0; s->irq = platform_get_irq(pdev, 0); -- cgit v1.2.1 From 2d47b7160243b1422006b91debf438484a4fde58 Mon Sep 17 00:00:00 2001 From: Bill Pemberton Date: Mon, 19 Nov 2012 13:21:34 -0500 Subject: tty: serial: remove use of __devexit_p CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer needed. Signed-off-by: Bill Pemberton Cc: Alan Cox Cc: Lucas Tavares Cc: "David S. Miller" Cc: Peter Korsgaard Cc: Tony Prisk Acked-by: Tobias Klauser Acked-by: Nicolas Ferre Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty/serial/mxs-auart.c') diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index d5b9e3039013..479acc88c17e 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -1155,7 +1155,7 @@ static int __devexit mxs_auart_remove(struct platform_device *pdev) static struct platform_driver mxs_auart_driver = { .probe = mxs_auart_probe, - .remove = __devexit_p(mxs_auart_remove), + .remove = mxs_auart_remove, .driver = { .name = "mxs-auart", .owner = THIS_MODULE, -- cgit v1.2.1 From 9671f09921d93e722a28ae9610d478e092ac5466 Mon Sep 17 00:00:00 2001 From: Bill Pemberton Date: Mon, 19 Nov 2012 13:21:50 -0500 Subject: tty: remove use of __devinit CONFIG_HOTPLUG is going away as an option so __devinit is no longer needed. Signed-off-by: Bill Pemberton Cc: Jiri Slaby Cc: Alan Cox Cc: Lucas Tavares Cc: "David S. Miller" Cc: Peter Korsgaard Cc: Tony Prisk Acked-by: Tobias Klauser Acked-by: Nicolas Ferre Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty/serial/mxs-auart.c') diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 479acc88c17e..18b55c2d1d2e 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -1046,7 +1046,7 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s, return 0; } -static int __devinit mxs_auart_probe(struct platform_device *pdev) +static int mxs_auart_probe(struct platform_device *pdev) { const struct of_device_id *of_id = of_match_device(mxs_auart_dt_ids, &pdev->dev); -- cgit v1.2.1 From ae8d8a146725a966bd7c59c94f4d0016dcf7a04f Mon Sep 17 00:00:00 2001 From: Bill Pemberton Date: Mon, 19 Nov 2012 13:26:18 -0500 Subject: tty: remove use of __devexit CONFIG_HOTPLUG is going away as an option so __devexit is no longer needed. Signed-off-by: Bill Pemberton Cc: Jiri Slaby Cc: Alan Cox Acked-by: Tobias Klauser Cc: Lucas Tavares Cc: Daniel Walker Cc: Bryan Huntsman Cc: "David S. Miller" Cc: Peter Korsgaard Cc: Tony Prisk Acked-by: David Brown Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty/serial/mxs-auart.c') diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 18b55c2d1d2e..3860ff27467c 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -1137,7 +1137,7 @@ out: return ret; } -static int __devexit mxs_auart_remove(struct platform_device *pdev) +static int mxs_auart_remove(struct platform_device *pdev) { struct mxs_auart_port *s = platform_get_drvdata(pdev); -- cgit v1.2.1 From a5919442bc61846e36011671df0d67c72275337e Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Thu, 22 Nov 2012 15:06:29 +0800 Subject: serial: mxs-auart: disable the Receive Timeout Interrupt when DMA is enabled When the DMA is enabled, the Receive Timeout interrupt is very easy to be arised in the 3M baud rate. The interrupt handler (aka mxs_auart_irq_handle) will call mxs_auart_rx_chars() to handle the received data. This is not right, we can not get the correct data from the RXFIFO now, the data have been moved to the DMA buffer by the DMA engine. This patch (1) disables the Receive Timeout Interrupt when the DMA is enabled, (2) and invoke the mxs_auart_rx_chars() only when the DMA is not enabled. Signed-off-by: Huang Shijie Tested-by: Lauri Hintsala Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/tty/serial/mxs-auart.c') diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 3860ff27467c..f56d6b92cf38 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -695,7 +695,8 @@ static void mxs_auart_settermios(struct uart_port *u, !test_and_set_bit(MXS_AUART_DMA_RX_READY, &s->flags)) { if (!mxs_auart_dma_prep_rx(s)) { /* Disable the normal RX interrupt. */ - writel(AUART_INTR_RXIEN, u->membase + AUART_INTR_CLR); + writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN, + u->membase + AUART_INTR_CLR); } else { mxs_auart_dma_exit(s); dev_err(s->dev, "We can not start up the DMA.\n"); @@ -719,7 +720,8 @@ static irqreturn_t mxs_auart_irq_handle(int irq, void *context) } if (istat & (AUART_INTR_RTIS | AUART_INTR_RXIS)) { - mxs_auart_rx_chars(s); + if (!auart_dma_enabled(s)) + mxs_auart_rx_chars(s); istat &= ~(AUART_INTR_RTIS | AUART_INTR_RXIS); } -- cgit v1.2.1 From d7ffb9329012a517575e4c4d49480b6ce0d1529e Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Thu, 22 Nov 2012 15:06:30 +0800 Subject: serial: mxs-auart: unmap the scatter list before we copy the data We should first unmap the DMA scatter list for receiving data, and then copy the data from the DMA buffer. The old code misses unmap the scatter list for RX. This patch fixes it. Signed-off-by: Huang Shijie Tested-by: Lauri Hintsala Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/tty/serial/mxs-auart.c') diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index f56d6b92cf38..6db23b035efe 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -461,6 +461,8 @@ static void dma_rx_callback(void *arg) int count; u32 stat; + dma_unmap_sg(s->dev, &s->rx_sgl, 1, DMA_FROM_DEVICE); + stat = readl(s->port.membase + AUART_STAT); stat &= ~(AUART_STAT_OERR | AUART_STAT_BERR | AUART_STAT_PERR | AUART_STAT_FERR); -- cgit v1.2.1