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Commit a6499435 authored by Cyrille Pitchen's avatar Cyrille Pitchen Committed by Greg Kroah-Hartman
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tty/serial: at91: fix I/O accesses on RHR and THR for AVR32 



This patch fixes I/O accesses on the Receiver Holding Register and on the
Transmitter Holding Register. Indeed AVR32 can only perform 32bit I/O
accesses on registers: using 8bit I/O accesses would read or write garbage
data.

Fixes: commit b5199d46 ("tty/serial: at91: add support to FIFOs")
Signed-off-by: default avatarCyrille Pitchen <cyrille.pitchen@atmel.com>
Tested-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b737eeb0

drivers/tty/serial/atmel_serial.c

+27 −10
Original line number Diff line number Diff line
@@ -204,16 +204,33 @@ static inline void atmel_uart_writel(struct uart_port *port, u32 reg, u32 value) 
	__raw_writel(value, port->membase + reg);

}



static inline u8 atmel_uart_readb(struct uart_port *port, u32 reg)

#ifdef CONFIG_AVR32



/* AVR32 cannot handle 8 or 16bit I/O accesses but only 32bit I/O accesses */

static inline u8 atmel_uart_read_char(struct uart_port *port)

{

	return __raw_readl(port->membase + ATMEL_US_RHR);

}



static inline void atmel_uart_write_char(struct uart_port *port, u8 value)

{

	return __raw_readb(port->membase + reg);

	__raw_writel(value, port->membase + ATMEL_US_THR);

}



static inline void atmel_uart_writeb(struct uart_port *port, u32 reg, u8 value)

#else



static inline u8 atmel_uart_read_char(struct uart_port *port)

{

	__raw_writeb(value, port->membase + reg);

	return __raw_readb(port->membase + ATMEL_US_RHR);

}



static inline void atmel_uart_write_char(struct uart_port *port, u8 value)

{

	__raw_writeb(value, port->membase + ATMEL_US_THR);

}



#endif



#ifdef CONFIG_SERIAL_ATMEL_PDC

static bool atmel_use_pdc_rx(struct uart_port *port)

{
@@ -658,7 +675,7 @@ static void atmel_rx_chars(struct uart_port *port) 


	status = atmel_uart_readl(port, ATMEL_US_CSR);

	while (status & ATMEL_US_RXRDY) {

		ch = atmel_uart_readb(port, ATMEL_US_RHR);

		ch = atmel_uart_read_char(port);



		/*

		 * note that the error handling code is
@@ -709,7 +726,7 @@ static void atmel_tx_chars(struct uart_port *port) 


	if (port->x_char &&

	    (atmel_uart_readl(port, ATMEL_US_CSR) & atmel_port->tx_done_mask)) {

		atmel_uart_writeb(port, ATMEL_US_THR, port->x_char);

		atmel_uart_write_char(port, port->x_char);

		port->icount.tx++;

		port->x_char = 0;

	}
@@ -718,7 +735,7 @@ static void atmel_tx_chars(struct uart_port *port) 


	while (atmel_uart_readl(port, ATMEL_US_CSR) &

	       atmel_port->tx_done_mask) {

		atmel_uart_writeb(port, ATMEL_US_THR, xmit->buf[xmit->tail]);

		atmel_uart_write_char(port, xmit->buf[xmit->tail]);

		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);

		port->icount.tx++;

		if (uart_circ_empty(xmit))
@@ -2294,7 +2311,7 @@ static int atmel_poll_get_char(struct uart_port *port) 
	while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_RXRDY))

		cpu_relax();



	return atmel_uart_readb(port, ATMEL_US_RHR);

	return atmel_uart_read_char(port);

}



static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
@@ -2302,7 +2319,7 @@ static void atmel_poll_put_char(struct uart_port *port, unsigned char ch) 
	while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY))

		cpu_relax();



	atmel_uart_writeb(port, ATMEL_US_THR, ch);

	atmel_uart_write_char(port, ch);

}

#endif
@@ -2409,7 +2426,7 @@ static void atmel_console_putchar(struct uart_port *port, int ch) 
{

	while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY))

		cpu_relax();

	atmel_uart_writeb(port, ATMEL_US_THR, ch);

	atmel_uart_write_char(port, ch);

}



/*