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Commit f7e54d7a authored by Stephen Boyd's avatar Stephen Boyd Committed by Greg Kroah-Hartman
Browse files

msm_serial: Add support for poll_{get,put}_char() 



Implement the polling functionality for the MSM serial driver.
This allows us to use KGDB on this hardware.

Cc: David Brown <davidb@codeaurora.org>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b28a960c

drivers/tty/serial/msm_serial.c

+137 −3
Original line number Diff line number Diff line
@@ -39,6 +39,13 @@ 


#include "msm_serial.h"



enum {

	UARTDM_1P1 = 1,

	UARTDM_1P2,

	UARTDM_1P3,

	UARTDM_1P4,

};



struct msm_port {

	struct uart_port	uart;

	char			name[16];
@@ -309,6 +316,8 @@ static unsigned int msm_get_mctrl(struct uart_port *port) 


static void msm_reset(struct uart_port *port)

{

	struct msm_port *msm_port = UART_TO_MSM(port);



	/* reset everything */

	msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);

	msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
@@ -316,6 +325,10 @@ static void msm_reset(struct uart_port *port) 
	msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR);

	msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);

	msm_write(port, UART_CR_CMD_SET_RFR, UART_CR);



	/* Disable DM modes */

	if (msm_port->is_uartdm)

		msm_write(port, 0, UARTDM_DMEN);

}



static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
@@ -711,6 +724,117 @@ static void msm_power(struct uart_port *port, unsigned int state, 
	}

}



#ifdef CONFIG_CONSOLE_POLL

static int msm_poll_init(struct uart_port *port)

{

	struct msm_port *msm_port = UART_TO_MSM(port);



	/* Enable single character mode on RX FIFO */

	if (msm_port->is_uartdm >= UARTDM_1P4)

		msm_write(port, UARTDM_DMEN_RX_SC_ENABLE, UARTDM_DMEN);



	return 0;

}



static int msm_poll_get_char_single(struct uart_port *port)

{

	struct msm_port *msm_port = UART_TO_MSM(port);

	unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : UART_RF;



	if (!(msm_read(port, UART_SR) & UART_SR_RX_READY))

		return NO_POLL_CHAR;

	else

		return msm_read(port, rf_reg) & 0xff;

}



static int msm_poll_get_char_dm_1p3(struct uart_port *port)

{

	int c;

	static u32 slop;

	static int count;

	unsigned char *sp = (unsigned char *)&slop;



	/* Check if a previous read had more than one char */

	if (count) {

		c = sp[sizeof(slop) - count];

		count--;

	/* Or if FIFO is empty */

	} else if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) {

		/*

		 * If RX packing buffer has less than a word, force stale to

		 * push contents into RX FIFO

		 */

		count = msm_read(port, UARTDM_RXFS);

		count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK;

		if (count) {

			msm_write(port, UART_CR_CMD_FORCE_STALE, UART_CR);

			slop = msm_read(port, UARTDM_RF);

			c = sp[0];

			count--;

		} else {

			c = NO_POLL_CHAR;

		}

	/* FIFO has a word */

	} else {

		slop = msm_read(port, UARTDM_RF);

		c = sp[0];

		count = sizeof(slop) - 1;

	}



	return c;

}



static int msm_poll_get_char(struct uart_port *port)

{

	u32 imr;

	int c;

	struct msm_port *msm_port = UART_TO_MSM(port);



	/* Disable all interrupts */

	imr = msm_read(port, UART_IMR);

	msm_write(port, 0, UART_IMR);



	if (msm_port->is_uartdm == UARTDM_1P3)

		c = msm_poll_get_char_dm_1p3(port);

	else

		c = msm_poll_get_char_single(port);



	/* Enable interrupts */

	msm_write(port, imr, UART_IMR);



	return c;

}



static void msm_poll_put_char(struct uart_port *port, unsigned char c)

{

	u32 imr;

	struct msm_port *msm_port = UART_TO_MSM(port);



	/* Disable all interrupts */

	imr = msm_read(port, UART_IMR);

	msm_write(port, 0, UART_IMR);



	if (msm_port->is_uartdm)

		reset_dm_count(port, 1);



	/* Wait until FIFO is empty */

	while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))

		cpu_relax();



	/* Write a character */

	msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : UART_TF);



	/* Wait until FIFO is empty */

	while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))

		cpu_relax();



	/* Enable interrupts */

	msm_write(port, imr, UART_IMR);



	return;

}

#endif



static struct uart_ops msm_uart_pops = {

	.tx_empty = msm_tx_empty,

	.set_mctrl = msm_set_mctrl,
@@ -729,6 +853,11 @@ static struct uart_ops msm_uart_pops = { 
	.config_port = msm_config_port,

	.verify_port = msm_verify_port,

	.pm = msm_power,

#ifdef CONFIG_CONSOLE_POLL

	.poll_init = msm_poll_init,

	.poll_get_char	= msm_poll_get_char,

	.poll_put_char	= msm_poll_put_char,

#endif

};



static struct msm_port msm_uart_ports[] = {
@@ -900,7 +1029,10 @@ static struct uart_driver msm_uart_driver = { 
static atomic_t msm_uart_next_id = ATOMIC_INIT(0);



static const struct of_device_id msm_uartdm_table[] = {

	{ .compatible = "qcom,msm-uartdm" },

	{ .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 },

	{ .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 },

	{ .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 },

	{ .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 },

	{ }

};
@@ -909,6 +1041,7 @@ static int __init msm_serial_probe(struct platform_device *pdev) 
	struct msm_port *msm_port;

	struct resource *resource;

	struct uart_port *port;

	const struct of_device_id *id;

	int irq;



	if (pdev->id == -1)
@@ -923,8 +1056,9 @@ static int __init msm_serial_probe(struct platform_device *pdev) 
	port->dev = &pdev->dev;

	msm_port = UART_TO_MSM(port);



	if (of_match_device(msm_uartdm_table, &pdev->dev))

		msm_port->is_uartdm = 1;

	id = of_match_device(msm_uartdm_table, &pdev->dev);

	if (id)

		msm_port->is_uartdm = (unsigned long)id->data;

	else

		msm_port->is_uartdm = 0;

drivers/tty/serial/msm_serial.h

+9 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ 
#define UART_CR_CMD_RESET_RFR		(14 << 4)

#define UART_CR_CMD_PROTECTION_EN	(16 << 4)

#define UART_CR_CMD_STALE_EVENT_ENABLE	(80 << 4)

#define UART_CR_CMD_FORCE_STALE		(4 << 8)

#define UART_CR_CMD_RESET_TX_READY	(3 << 8)

#define UART_CR_TX_DISABLE		(1 << 3)

#define UART_CR_TX_ENABLE		(1 << 2)
@@ -113,6 +114,14 @@ 
#define GSBI_PROTOCOL_UART	0x40

#define GSBI_PROTOCOL_IDLE	0x0



#define UARTDM_RXFS		0x50

#define UARTDM_RXFS_BUF_SHIFT	0x7

#define UARTDM_RXFS_BUF_MASK	0x7



#define UARTDM_DMEN		0x3C

#define UARTDM_DMEN_RX_SC_ENABLE BIT(5)

#define UARTDM_DMEN_TX_SC_ENABLE BIT(4)



#define UARTDM_DMRX		0x34

#define UARTDM_NCF_TX		0x40

#define UARTDM_RX_TOTAL_SNAP	0x38