diff options
| -rw-r--r-- | drivers/tty/serial/8250/8250_omap.c | 98 |
1 files changed, 86 insertions, 12 deletions
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 9293a3e94f07..f34cdb734186 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -40,6 +40,7 @@ * The same errata is applicable to AM335x and DRA7x processors too. */ #define UART_ERRATA_CLOCK_DISABLE (1 << 3) +#define UART_HAS_EFR2 BIT(4) #define OMAP_UART_FCR_RX_TRIG 6 #define OMAP_UART_FCR_TX_TRIG 4 @@ -93,6 +94,10 @@ #define OMAP_UART_REV_52 0x0502 #define OMAP_UART_REV_63 0x0603 +/* Enhanced features register 2 */ +#define UART_OMAP_EFR2 0x23 +#define UART_OMAP_EFR2_TIMEOUT_BEHAVE BIT(6) + struct omap8250_priv { int line; u8 habit; @@ -664,7 +669,7 @@ static int omap_8250_startup(struct uart_port *port) priv->wer |= OMAP_UART_TX_WAKEUP_EN; serial_out(up, UART_OMAP_WER, priv->wer); - if (up->dma) + if (up->dma && !(priv->habit & UART_HAS_EFR2)) up->dma->rx_dma(up); pm_runtime_mark_last_busy(port->dev); @@ -689,6 +694,8 @@ static void omap_8250_shutdown(struct uart_port *port) pm_runtime_get_sync(port->dev); serial_out(up, UART_OMAP_WER, 0); + if (priv->habit & UART_HAS_EFR2) + serial_out(up, UART_OMAP_EFR2, 0x0); up->ier = 0; serial_out(up, UART_IER, 0); @@ -818,8 +825,12 @@ static void __dma_rx_complete(void *param) return; } __dma_rx_do_complete(p); - if (!priv->throttled) - omap_8250_rx_dma(p); + if (!priv->throttled) { + p->ier |= UART_IER_RLSI | UART_IER_RDI; + serial_out(p, UART_IER, p->ier); + if (!(priv->habit & UART_HAS_EFR2)) + omap_8250_rx_dma(p); + } spin_unlock_irqrestore(&p->port.lock, flags); } @@ -862,8 +873,20 @@ static int omap_8250_rx_dma(struct uart_8250_port *p) spin_lock_irqsave(&priv->rx_dma_lock, flags); - if (dma->rx_running) + if (dma->rx_running) { + enum dma_status state; + + state = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, NULL); + if (state == DMA_COMPLETE) { + /* + * Disable RX interrupts to allow RX DMA completion + * callback to run. + */ + p->ier &= ~(UART_IER_RLSI | UART_IER_RDI); + serial_out(p, UART_IER, p->ier); + } goto out; + } desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM, @@ -1034,6 +1057,46 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) return omap_8250_rx_dma(up); } +static unsigned char omap_8250_handle_rx_dma(struct uart_8250_port *up, + u8 iir, unsigned char status) +{ + if ((status & (UART_LSR_DR | UART_LSR_BI)) && + (iir & UART_IIR_RDI)) { + if (handle_rx_dma(up, iir)) { + status = serial8250_rx_chars(up, status); + omap_8250_rx_dma(up); + } + } + + return status; +} + +static void am654_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir, + unsigned char status) +{ + /* + * Queue a new transfer if FIFO has data. + */ + if ((status & (UART_LSR_DR | UART_LSR_BI)) && + (up->ier & UART_IER_RDI)) { + omap_8250_rx_dma(up); + serial_out(up, UART_OMAP_EFR2, UART_OMAP_EFR2_TIMEOUT_BEHAVE); + } else if ((iir & 0x3f) == UART_IIR_RX_TIMEOUT) { + /* + * Disable RX timeout, read IIR to clear + * current timeout condition, clear EFR2 to + * periodic timeouts, re-enable interrupts. + */ + up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); + serial_out(up, UART_IER, up->ier); + omap_8250_rx_dma_flush(up); + serial_in(up, UART_IIR); + serial_out(up, UART_OMAP_EFR2, 0x0); + up->ier |= UART_IER_RLSI | UART_IER_RDI; + serial_out(up, UART_IER, up->ier); + } +} + /* * This is mostly serial8250_handle_irq(). We have a slightly different DMA * hoook for RX/TX and need different logic for them in the ISR. Therefore we @@ -1042,6 +1105,7 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) static int omap_8250_dma_handle_irq(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); + struct omap8250_priv *priv = up->port.private_data; unsigned char status; unsigned long flags; u8 iir; @@ -1058,12 +1122,11 @@ static int omap_8250_dma_handle_irq(struct uart_port *port) status = serial_port_in(port, UART_LSR); - if (status & (UART_LSR_DR | UART_LSR_BI)) { - if (handle_rx_dma(up, iir)) { - status = serial8250_rx_chars(up, status); - omap_8250_rx_dma(up); - } - } + if (priv->habit & UART_HAS_EFR2) + am654_8250_handle_rx_dma(up, iir, status); + else + status = omap_8250_handle_rx_dma(up, iir, status); + serial8250_modem_status(up); if (status & UART_LSR_THRE && up->dma->tx_err) { if (uart_tx_stopped(&up->port) || @@ -1105,12 +1168,23 @@ static int omap8250_no_handle_irq(struct uart_port *port) return 0; } +static struct omap8250_dma_params am654_dma = { + .rx_size = SZ_2K, + .rx_trigger = 1, + .tx_trigger = TX_TRIGGER, +}; + static struct omap8250_dma_params am33xx_dma = { .rx_size = RX_TRIGGER, .rx_trigger = RX_TRIGGER, .tx_trigger = TX_TRIGGER, }; +static struct omap8250_platdata am654_platdata = { + .dma_params = &am654_dma, + .habit = UART_HAS_EFR2, +}; + static struct omap8250_platdata am33xx_platdata = { .dma_params = &am33xx_dma, .habit = OMAP_DMA_TX_KICK | UART_ERRATA_CLOCK_DISABLE, @@ -1122,7 +1196,7 @@ static struct omap8250_platdata omap4_platdata = { }; static const struct of_device_id omap8250_dt_ids[] = { - { .compatible = "ti,am654-uart" }, + { .compatible = "ti,am654-uart", .data = &am654_platdata, }, { .compatible = "ti,omap2-uart" }, { .compatible = "ti,omap3-uart" }, { .compatible = "ti,omap4-uart", .data = &omap4_platdata, }, @@ -1492,7 +1566,7 @@ static int omap8250_runtime_resume(struct device *dev) if (omap8250_lost_context(up)) omap8250_restore_regs(up); - if (up->dma && up->dma->rxchan) + if (up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2)) omap_8250_rx_dma(up); priv->latency = priv->calc_latency; |