From a1b5b43ffb84945cbdc5cbdb993d3195c7e77cbb Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 21 Aug 2015 20:02:25 +0200 Subject: serial: sh-sci: Replace buggy big #ifdef by runtime logic The #ifdef logic to clear SCxSR bits using RMW on SCIFA/SCIFB and SCIF variants with some SCIFA features (sh7705/SH7720/sh7721) has several drawbacks: - It wasn't updated for newer R-Mobile variants (APE6), - It doesn't correctly handle SoCs with both SCIF and SCIFA/B (e.g. R-Car Gen2, but also legacy sh7723/sh7724), - It doesn't play well with ARM multi-platform kernels: on R-Car Gen2, SCIF/SCIFA/SCIFB/HSCIF were handled differently, depending on whether r8a7740 or sh73a0 support was enabled or not, Replace the #ifdef logic by runtime logic to fix this. SCIFA/SCIFB and SCIF on sh7705/sh7720/sh7721 use RMW to clear error bits, other variants use plain stores, as before. Note that this changes behavior for SCIFA on sh7723/sh7724 (these SoCs have both SCIF and SCIFA), which didn't use RMW before. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 36 ++++++++++++++++++++++++++---------- 1 file changed, 26 insertions(+), 10 deletions(-) (limited to 'drivers/tty/serial/sh-sci.c') diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 1b2f894bdc9e..b014fce1509d 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -489,6 +489,22 @@ static void sci_port_disable(struct sci_port *sci_port) pm_runtime_put_sync(sci_port->port.dev); } +static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask) +{ + if (port->type == PORT_SCI) { + /* Just store the mask */ + serial_port_out(port, SCxSR, mask); + } else if (to_sci_port(port)->overrun_mask == SCIFA_ORER) { + /* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */ + /* Only clear the status bits we want to clear */ + serial_port_out(port, SCxSR, + serial_port_in(port, SCxSR) & mask); + } else { + /* Store the mask, clear parity/framing errors */ + serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC)); + } +} + #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) #ifdef CONFIG_CONSOLE_POLL @@ -500,7 +516,7 @@ static int sci_poll_get_char(struct uart_port *port) do { status = serial_port_in(port, SCxSR); if (status & SCxSR_ERRORS(port)) { - serial_port_out(port, SCxSR, SCxSR_ERROR_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port)); continue; } break; @@ -513,7 +529,7 @@ static int sci_poll_get_char(struct uart_port *port) /* Dummy read */ serial_port_in(port, SCxSR); - serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); return c; } @@ -528,7 +544,7 @@ static void sci_poll_put_char(struct uart_port *port, unsigned char c) } while (!(status & SCxSR_TDxE(port))); serial_port_out(port, SCxTDR, c); - serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port)); + sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port)); } #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */ @@ -655,7 +671,7 @@ static void sci_transmit_chars(struct uart_port *port) port->icount.tx++; } while (--count > 0); - serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port)); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); @@ -666,7 +682,7 @@ static void sci_transmit_chars(struct uart_port *port) if (port->type != PORT_SCI) { serial_port_in(port, SCxSR); /* Dummy read */ - serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port)); } ctrl |= SCSCR_TIE; @@ -750,7 +766,7 @@ static void sci_receive_chars(struct uart_port *port) } serial_port_in(port, SCxSR); /* dummy read */ - serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); copied += count; port->icount.rx += count; @@ -761,7 +777,7 @@ static void sci_receive_chars(struct uart_port *port) tty_flip_buffer_push(tport); } else { serial_port_in(port, SCxSR); /* dummy read */ - serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); } } @@ -982,14 +998,14 @@ static irqreturn_t sci_er_interrupt(int irq, void *ptr) if (sci_handle_errors(port)) { /* discard character in rx buffer */ serial_port_in(port, SCxSR); - serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); } } else { sci_handle_fifo_overrun(port); sci_rx_interrupt(irq, ptr); } - serial_port_out(port, SCxSR, SCxSR_ERROR_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port)); /* Kick the transmission */ sci_tx_interrupt(irq, ptr); @@ -1003,7 +1019,7 @@ static irqreturn_t sci_br_interrupt(int irq, void *ptr) /* Handle BREAKs */ sci_handle_breaks(port); - serial_port_out(port, SCxSR, SCxSR_BREAK_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port)); return IRQ_HANDLED; } -- cgit v1.2.3