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Commit 1f7d1c85 authored by Sonic Zhang's avatar Sonic Zhang Committed by Greg Kroah-Hartman
Browse files

serial: bfin_sport_uart: add support for CTS/RTS via GPIOs 



Some people need flow control on their ports, so now boards can support
that via any GPIOs.

Signed-off-by: default avatarSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent b59588aa

drivers/serial/Kconfig

+24 −0
Original line number Diff line number Diff line
@@ -1443,24 +1443,48 @@ config SERIAL_BFIN_SPORT0_UART 
	help

	  Enable UART over SPORT0



config SERIAL_BFIN_SPORT0_UART_CTSRTS

	bool "Enable UART over SPORT0 hardware flow control"

	depends on SERIAL_BFIN_SPORT0_UART

	help

	  Enable hardware flow control in the driver.



config SERIAL_BFIN_SPORT1_UART

	bool "Enable UART over SPORT1"

	depends on SERIAL_BFIN_SPORT

	help

	  Enable UART over SPORT1



config SERIAL_BFIN_SPORT1_UART_CTSRTS

	bool "Enable UART over SPORT1 hardware flow control"

	depends on SERIAL_BFIN_SPORT1_UART

	help

	  Enable hardware flow control in the driver.



config SERIAL_BFIN_SPORT2_UART

	bool "Enable UART over SPORT2"

	depends on SERIAL_BFIN_SPORT && (BF54x || BF538 || BF539)

	help

	  Enable UART over SPORT2



config SERIAL_BFIN_SPORT2_UART_CTSRTS

	bool "Enable UART over SPORT2 hardware flow control"

	depends on SERIAL_BFIN_SPORT2_UART

	help

	  Enable hardware flow control in the driver.



config SERIAL_BFIN_SPORT3_UART

	bool "Enable UART over SPORT3"

	depends on SERIAL_BFIN_SPORT && (BF54x || BF538 || BF539)

	help

	  Enable UART over SPORT3



config SERIAL_BFIN_SPORT3_UART_CTSRTS

	bool "Enable UART over SPORT3 hardware flow control"

	depends on SERIAL_BFIN_SPORT3_UART

	help

	  Enable hardware flow control in the driver.



config SERIAL_TIMBERDALE

	tristate "Support for timberdale UART"

	select SERIAL_CORE

drivers/serial/bfin_sport_uart.c

+100 −11
Original line number Diff line number Diff line
@@ -48,6 +48,10 @@ struct sport_uart_port { 
	unsigned short		txmask2;

	unsigned char		stopb;

/*	unsigned char		parib; */

#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS

	int cts_pin;

	int rts_pin;

#endif

};



static void sport_uart_tx_chars(struct sport_uart_port *up);
@@ -198,6 +202,59 @@ static irqreturn_t sport_uart_err_irq(int irq, void *dev_id) 
	return IRQ_HANDLED;

}



#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS

static unsigned int sport_get_mctrl(struct uart_port *port)

{

	struct sport_uart_port *up = (struct sport_uart_port *)port;

	if (up->cts_pin < 0)

		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;



	/* CTS PIN is negative assertive. */

	if (SPORT_UART_GET_CTS(up))

		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;

	else

		return TIOCM_DSR | TIOCM_CAR;

}



static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)

{

	struct sport_uart_port *up = (struct sport_uart_port *)port;

	if (up->rts_pin < 0)

		return;



	/* RTS PIN is negative assertive. */

	if (mctrl & TIOCM_RTS)

		SPORT_UART_ENABLE_RTS(up);

	else

		SPORT_UART_DISABLE_RTS(up);

}



/*

 * Handle any change of modem status signal.

 */

static irqreturn_t sport_mctrl_cts_int(int irq, void *dev_id)

{

	struct sport_uart_port *up = (struct sport_uart_port *)dev_id;

	unsigned int status;



	status = sport_get_mctrl(&up->port);

	uart_handle_cts_change(&up->port, status & TIOCM_CTS);



	return IRQ_HANDLED;

}

#else

static unsigned int sport_get_mctrl(struct uart_port *port)

{

	pr_debug("%s enter\n", __func__);

	return TIOCM_CTS | TIOCM_CD | TIOCM_DSR;

}



static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)

{

	pr_debug("%s enter\n", __func__);

}

#endif



/* Reqeust IRQ, Setup clock */

static int sport_startup(struct uart_port *port)

{
@@ -226,6 +283,21 @@ static int sport_startup(struct uart_port *port) 
		goto fail2;

	}



#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS

	if (up->cts_pin >= 0) {

		if (request_irq(gpio_to_irq(up->cts_pin),

			sport_mctrl_cts_int,

			IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |

			IRQF_DISABLED, "BFIN_SPORT_UART_CTS", up)) {

			up->cts_pin = -1;

			dev_info(port->dev, "Unable to attach BlackFin UART \

				over SPORT CTS interrupt. So, disable it.\n");

		}

	}

	if (up->rts_pin >= 0)

		gpio_direction_output(up->rts_pin, 0);

#endif



	return 0;

 fail2:

	free_irq(up->port.irq+1, up);
@@ -283,17 +355,6 @@ static unsigned int sport_tx_empty(struct uart_port *port) 
		return 0;

}



static unsigned int sport_get_mctrl(struct uart_port *port)

{

	pr_debug("%s enter\n", __func__);

	return (TIOCM_CTS | TIOCM_CD | TIOCM_DSR);

}



static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)

{

	pr_debug("%s enter\n", __func__);

}



static void sport_stop_tx(struct uart_port *port)

{

	struct sport_uart_port *up = (struct sport_uart_port *)port;
@@ -364,6 +425,10 @@ static void sport_shutdown(struct uart_port *port) 
	free_irq(up->port.irq, up);

	free_irq(up->port.irq+1, up);

	free_irq(up->err_irq, up);

#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS

	if (up->cts_pin >= 0)

		free_irq(gpio_to_irq(up->cts_pin), up);

#endif

}



static const char *sport_type(struct uart_port *port)
@@ -536,7 +601,11 @@ sport_uart_console_setup(struct console *co, char *options) 
	int baud = 57600;

	int bits = 8;

	int parity = 'n';

# ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS

	int flow = 'r';

# else

	int flow = 'n';

# endif



	/* Check whether an invalid uart number has been specified */

	if (co->index < 0 || co->index >= BFIN_SPORT_UART_MAX_PORTS)
@@ -729,6 +798,22 @@ static int __devinit sport_uart_probe(struct platform_device *pdev) 
			ret = -ENOENT;

			goto out_error_unmap;

		}

#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS

		res = platform_get_resource(pdev, IORESOURCE_IO, 0);

		if (res == NULL)

			sport->cts_pin = -1;

		else

			sport->cts_pin = res->start;



		res = platform_get_resource(pdev, IORESOURCE_IO, 1);

		if (res == NULL)

			sport->rts_pin = -1;

		else

			sport->rts_pin = res->start;



		if (sport->rts_pin >= 0)

			gpio_request(sport->rts_pin, DRV_NAME);

#endif

	}



#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
@@ -767,6 +852,10 @@ static int __devexit sport_uart_remove(struct platform_device *pdev) 


	if (sport) {

		uart_remove_one_port(&sport_uart_reg, &sport->port);

#ifdef CONFIG_SERIAL_BFIN_CTSRTS

		if (sport->rts_pin >= 0)

			gpio_free(sport->rts_pin);

#endif

		iounmap(sport->port.membase);

		peripheral_free_list(

			(unsigned short *)pdev->dev.platform_data);

drivers/serial/bfin_sport_uart.h

+11 −0
Original line number Diff line number Diff line
@@ -72,4 +72,15 @@ 


#define SPORT_TX_FIFO_SIZE	8



#define SPORT_UART_GET_CTS(x)		gpio_get_value(x->cts_pin)

#define SPORT_UART_DISABLE_RTS(x)	gpio_set_value(x->rts_pin, 1)

#define SPORT_UART_ENABLE_RTS(x)	gpio_set_value(x->rts_pin, 0)



#if defined(CONFIG_SERIAL_BFIN_SPORT0_UART_CTSRTS) \

	|| defined(CONFIG_SERIAL_BFIN_SPORT1_UART_CTSRTS) \

	|| defined(CONFIG_SERIAL_BFIN_SPORT2_UART_CTSRTS) \

	|| defined(CONFIG_SERIAL_BFIN_SPORT3_UART_CTSRTS)

# define CONFIG_SERIAL_BFIN_SPORT_CTSRTS

#endif



#endif /* _BFIN_SPORT_UART_H */