From 77285243a68fec6852041d1db0d5587684b9dc48 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Mon, 29 Sep 2014 20:06:48 +0200 Subject: [PATCH] tty: serial: 8250: omap: add custom irq handling We have (or will have) custom DMA callbacks in the omap driver due to the different behaviour in the RX and TX case. To make this work we need a few changes in the IRQ handler to invoke the rx_handler again after the "manual" mode or retry the tx_handler again before falling back to the manual mode. Heikki didn't want to see the extra hacks in the generic / default irq handler and Peter wasn't too happy about an OMAP-only IRQ handler. The way I planned it is to use this extra IRQ routine only in DMA case. If Peter dislike this approach then I hope Heikki doesn't block changes in the default IRQ handler :) Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Heikki Krogerus Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250.h | 2 ++ drivers/tty/serial/8250/8250_core.c | 6 ++-- drivers/tty/serial/8250/8250_omap.c | 55 +++++++++++++++++++++++++++++ 3 files changed, 61 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h index 0dc1cb6b2706..458ad28338fe 100644 --- a/drivers/tty/serial/8250/8250.h +++ b/drivers/tty/serial/8250/8250.h @@ -119,6 +119,8 @@ static inline void serial_dl_write(struct uart_8250_port *up, int value) } struct uart_8250_port *serial8250_get_port(int line); +void serial8250_rpm_get(struct uart_8250_port *p); +void serial8250_rpm_put(struct uart_8250_port *p); #if defined(__alpha__) && !defined(CONFIG_PCI) /* diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 39450ba03a2f..7e78f3077b5d 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -541,20 +541,22 @@ void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p) } EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos); -static void serial8250_rpm_get(struct uart_8250_port *p) +void serial8250_rpm_get(struct uart_8250_port *p) { if (!(p->capabilities & UART_CAP_RPM)) return; pm_runtime_get_sync(p->port.dev); } +EXPORT_SYMBOL_GPL(serial8250_rpm_get); -static void serial8250_rpm_put(struct uart_8250_port *p) +void serial8250_rpm_put(struct uart_8250_port *p) { if (!(p->capabilities & UART_CAP_RPM)) return; pm_runtime_mark_last_busy(p->port.dev); pm_runtime_put_autosuspend(p->port.dev); } +EXPORT_SYMBOL_GPL(serial8250_rpm_put); /* * These two wrappers ensure that enable_runtime_pm_tx() can be called more than diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 1659858e595a..6500547f8fda 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -854,6 +855,60 @@ err: return ret; } +/* + * 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 + * use the default routine in the non-DMA case and this one for with DMA. + */ +static int omap_8250_dma_handle_irq(struct uart_port *port) +{ + struct uart_8250_port *up = up_to_u8250p(port); + unsigned char status; + unsigned long flags; + u8 iir; + int dma_err = 0; + + serial8250_rpm_get(up); + + iir = serial_port_in(port, UART_IIR); + if (iir & UART_IIR_NO_INT) { + serial8250_rpm_put(up); + return 0; + } + + spin_lock_irqsave(&port->lock, flags); + + status = serial_port_in(port, UART_LSR); + + if (status & (UART_LSR_DR | UART_LSR_BI)) { + + dma_err = omap_8250_rx_dma(up, iir); + if (dma_err) { + status = serial8250_rx_chars(up, status); + omap_8250_rx_dma(up, 0); + } + } + serial8250_modem_status(up); + if (status & UART_LSR_THRE && up->dma->tx_err) { + if (uart_tx_stopped(&up->port) || + uart_circ_empty(&up->port.state->xmit)) { + up->dma->tx_err = 0; + serial8250_tx_chars(up); + } else { + /* + * try again due to an earlier failer which + * might have been resolved by now. + */ + dma_err = omap_8250_tx_dma(up); + if (dma_err) + serial8250_tx_chars(up); + } + } + + spin_unlock_irqrestore(&port->lock, flags); + serial8250_rpm_put(up); + return 1; +} #endif static int omap8250_probe(struct platform_device *pdev) -- 2.20.1