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Commit a1b5b43f authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Greg Kroah-Hartman
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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: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9a23a1d1

drivers/tty/serial/sh-sci.c

+26 −10
Original line number Diff line number Diff line
@@ -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;

}

drivers/tty/serial/sh-sci.h

+8 −25
Original line number Diff line number Diff line
@@ -119,28 +119,11 @@ enum { 


#define SCxSR_ERRORS(port)	(to_sci_port(port)->error_mask)



#if defined(CONFIG_CPU_SUBTYPE_SH7705) || \

    defined(CONFIG_CPU_SUBTYPE_SH7720) || \

    defined(CONFIG_CPU_SUBTYPE_SH7721) || \

    defined(CONFIG_ARCH_SH73A0) || \

    defined(CONFIG_ARCH_R8A7740)



# define SCxSR_RDxF_CLEAR(port) \

	(serial_port_in(port, SCxSR) & SCIF_RDxF_CLEAR)

# define SCxSR_ERROR_CLEAR(port) \

	(serial_port_in(port, SCxSR) & SCIF_ERROR_CLEAR)

# define SCxSR_TDxE_CLEAR(port) \

	(serial_port_in(port, SCxSR) & SCIF_TDxE_CLEAR)

# define SCxSR_BREAK_CLEAR(port) \

	(serial_port_in(port, SCxSR) & SCIF_BREAK_CLEAR)

#else

#define SCxSR_RDxF_CLEAR(port) \

	((((port)->type == PORT_SCI) ? SCI_RDxF_CLEAR : SCIF_RDxF_CLEAR) & 0xff)

	(((port)->type == PORT_SCI) ? SCI_RDxF_CLEAR : SCIF_RDxF_CLEAR)

#define SCxSR_ERROR_CLEAR(port) \

	((((port)->type == PORT_SCI) ? SCI_ERROR_CLEAR : SCIF_ERROR_CLEAR) & 0xff)

	(((port)->type == PORT_SCI) ? SCI_ERROR_CLEAR : SCIF_ERROR_CLEAR)

#define SCxSR_TDxE_CLEAR(port) \

	((((port)->type == PORT_SCI) ? SCI_TDxE_CLEAR : SCIF_TDxE_CLEAR) & 0xff)

	(((port)->type == PORT_SCI) ? SCI_TDxE_CLEAR : SCIF_TDxE_CLEAR)

#define SCxSR_BREAK_CLEAR(port) \

	((((port)->type == PORT_SCI) ? SCI_BREAK_CLEAR : SCIF_BREAK_CLEAR) & 0xff)

#endif

	(((port)->type == PORT_SCI) ? SCI_BREAK_CLEAR : SCIF_BREAK_CLEAR)