drivers/serial/serial_pl01x.c - github/trini/u-boot - Gitiles

 /*
  * (C) Copyright 2000
  * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
  *
  * (C) Copyright 2004
  * ARM Ltd.
  * Philippe Robin, <philippe.robin@arm.com>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */

 /* Simple U-Boot driver for the PrimeCell PL010/PL011 UARTs */

 #include <common.h>
 #include <dm.h>
 #include <errno.h>
 #include <watchdog.h>
 #include <asm/io.h>
 #include <serial.h>
 #include <dm/platform_data/serial_pl01x.h>
 #include <linux/compiler.h>
 #include "serial_pl01x_internal.h"

 #ifndef CONFIG_DM_SERIAL

 static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
 static enum pl01x_type pl01x_type __attribute__ ((section(".data")));
 static struct pl01x_regs *base_regs __attribute__ ((section(".data")));
 #define NUM_PORTS (sizeof(port)/sizeof(port[0]))

 DECLARE_GLOBAL_DATA_PTR;
 #endif

 static int pl01x_putc(struct pl01x_regs *regs, char c)
 {
 	/* Wait until there is space in the FIFO */
 	if (readl(&regs->fr) & UART_PL01x_FR_TXFF)
 		return -EAGAIN;

 	/* Send the character */
 	writel(c, &regs->dr);

 	return 0;
 }

 static int pl01x_getc(struct pl01x_regs *regs)
 {
 	unsigned int data;

 	/* Wait until there is data in the FIFO */
 	if (readl(&regs->fr) & UART_PL01x_FR_RXFE)
 		return -EAGAIN;

 	data = readl(&regs->dr);

 	/* Check for an error flag */
 	if (data & 0xFFFFFF00) {
 		/* Clear the error */
 		writel(0xFFFFFFFF, &regs->ecr);
 		return -1;
 	}

 	return (int) data;
 }

 static int pl01x_tstc(struct pl01x_regs *regs)
 {
 	WATCHDOG_RESET();
 	return !(readl(&regs->fr) & UART_PL01x_FR_RXFE);
 }

 static int pl01x_generic_serial_init(struct pl01x_regs *regs,
 				     enum pl01x_type type)
 {
 	switch (type) {
 	case TYPE_PL010:
 		/* disable everything */
 		writel(0, &regs->pl010_cr);
 		break;
 	case TYPE_PL011:
 #ifdef CONFIG_PL011_SERIAL_FLUSH_ON_INIT
 		/* Empty RX fifo if necessary */
 		if (readl(&regs->pl011_cr) & UART_PL011_CR_UARTEN) {
 			while (!(readl(&regs->fr) & UART_PL01x_FR_RXFE))
 				readl(&regs->dr);
 		}
 #endif
 		/* disable everything */
 		writel(0, &regs->pl011_cr);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int set_line_control(struct pl01x_regs *regs)
 {
 	unsigned int lcr;
 	/*
 	 * Internal update of baud rate register require line
 	 * control register write
 	 */
 	lcr = UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN;
 #ifdef CONFIG_PL011_SERIAL_RLCR
 	{
 		int i;

 		/*
 		 * Program receive line control register after waiting
 		 * 10 bus cycles.  Delay be writing to readonly register
 		 * 10 times
 		 */
 		for (i = 0; i < 10; i++)
 			writel(lcr, &regs->fr);

 		writel(lcr, &regs->pl011_rlcr);
 	}
 #endif
 	writel(lcr, &regs->pl011_lcrh);
 	return 0;
 }

 static int pl01x_generic_setbrg(struct pl01x_regs *regs, enum pl01x_type type,
 				int clock, int baudrate)
 {
 	switch (type) {
 	case TYPE_PL010: {
 		unsigned int divisor;

 		switch (baudrate) {
 		case 9600:
 			divisor = UART_PL010_BAUD_9600;
 			break;
 		case 19200:
 			divisor = UART_PL010_BAUD_9600;
 			break;
 		case 38400:
 			divisor = UART_PL010_BAUD_38400;
 			break;
 		case 57600:
 			divisor = UART_PL010_BAUD_57600;
 			break;
 		case 115200:
 			divisor = UART_PL010_BAUD_115200;
 			break;
 		default:
 			divisor = UART_PL010_BAUD_38400;
 		}

 		writel((divisor & 0xf00) >> 8, &regs->pl010_lcrm);
 		writel(divisor & 0xff, &regs->pl010_lcrl);

 		/* Finally, enable the UART */
 		writel(UART_PL010_CR_UARTEN, &regs->pl010_cr);
 		break;
 	}
 	case TYPE_PL011: {
 		unsigned int temp;
 		unsigned int divider;
 		unsigned int remainder;
 		unsigned int fraction;

 		/*
 		* Set baud rate
 		*
 		* IBRD = UART_CLK / (16 * BAUD_RATE)
 		* FBRD = RND((64 * MOD(UART_CLK,(16 * BAUD_RATE)))
 		*		/ (16 * BAUD_RATE))
 		*/
 		temp = 16 * baudrate;
 		divider = clock / temp;
 		remainder = clock % temp;
 		temp = (8 * remainder) / baudrate;
 		fraction = (temp >> 1) + (temp & 1);

 		writel(divider, &regs->pl011_ibrd);
 		writel(fraction, &regs->pl011_fbrd);

 		set_line_control(regs);
 		/* Finally, enable the UART */
 		writel(UART_PL011_CR_UARTEN | UART_PL011_CR_TXE |
 		       UART_PL011_CR_RXE | UART_PL011_CR_RTS, &regs->pl011_cr);
 		break;
 	}
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 #ifndef CONFIG_DM_SERIAL
 static void pl01x_serial_init_baud(int baudrate)
 {
 	int clock = 0;

 #if defined(CONFIG_PL010_SERIAL)
 	pl01x_type = TYPE_PL010;
 #elif defined(CONFIG_PL011_SERIAL)
 	pl01x_type = TYPE_PL011;
 	clock = CONFIG_PL011_CLOCK;
 #endif
 	base_regs = (struct pl01x_regs *)port[CONFIG_CONS_INDEX];

 	pl01x_generic_serial_init(base_regs, pl01x_type);
 	pl01x_generic_setbrg(base_regs, pl01x_type, clock, baudrate);
 }

 /*
  * Integrator AP has two UARTs, we use the first one, at 38400-8-N-1
  * Integrator CP has two UARTs, use the first one, at 38400-8-N-1
  * Versatile PB has four UARTs.
  */
 int pl01x_serial_init(void)
 {
 	pl01x_serial_init_baud(CONFIG_BAUDRATE);

 	return 0;
 }

 static void pl01x_serial_putc(const char c)
 {
 	if (c == '\n')
 		while (pl01x_putc(base_regs, '\r') == -EAGAIN);

 	while (pl01x_putc(base_regs, c) == -EAGAIN);
 }

 static int pl01x_serial_getc(void)
 {
 	while (1) {
 		int ch = pl01x_getc(base_regs);

 		if (ch == -EAGAIN) {
 			WATCHDOG_RESET();
 			continue;
 		}

 		return ch;
 	}
 }

 static int pl01x_serial_tstc(void)
 {
 	return pl01x_tstc(base_regs);
 }

 static void pl01x_serial_setbrg(void)
 {
 	/*
 	 * Flush FIFO and wait for non-busy before changing baudrate to avoid
 	 * crap in console
 	 */
 	while (!(readl(&base_regs->fr) & UART_PL01x_FR_TXFE))
 		WATCHDOG_RESET();
 	while (readl(&base_regs->fr) & UART_PL01x_FR_BUSY)
 		WATCHDOG_RESET();
 	pl01x_serial_init_baud(gd->baudrate);
 }

 static struct serial_device pl01x_serial_drv = {
 	.name	= "pl01x_serial",
 	.start	= pl01x_serial_init,
 	.stop	= NULL,
 	.setbrg	= pl01x_serial_setbrg,
 	.putc	= pl01x_serial_putc,
 	.puts	= default_serial_puts,
 	.getc	= pl01x_serial_getc,
 	.tstc	= pl01x_serial_tstc,
 };

 void pl01x_serial_initialize(void)
 {
 	serial_register(&pl01x_serial_drv);
 }

 __weak struct serial_device *default_serial_console(void)
 {
 	return &pl01x_serial_drv;
 }

 #endif /* nCONFIG_DM_SERIAL */

 #ifdef CONFIG_DM_SERIAL

 struct pl01x_priv {
 	struct pl01x_regs *regs;
 	enum pl01x_type type;
 };

 static int pl01x_serial_setbrg(struct udevice *dev, int baudrate)
 {
 	struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
 	struct pl01x_priv *priv = dev_get_priv(dev);

 	pl01x_generic_setbrg(priv->regs, priv->type, plat->clock, baudrate);

 	return 0;
 }

 static int pl01x_serial_probe(struct udevice *dev)
 {
 	struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
 	struct pl01x_priv *priv = dev_get_priv(dev);

 	priv->regs = (struct pl01x_regs *)plat->base;
 	priv->type = plat->type;
 	return pl01x_generic_serial_init(priv->regs, priv->type);
 }

 static int pl01x_serial_getc(struct udevice *dev)
 {
 	struct pl01x_priv *priv = dev_get_priv(dev);

 	return pl01x_getc(priv->regs);
 }

 static int pl01x_serial_putc(struct udevice *dev, const char ch)
 {
 	struct pl01x_priv *priv = dev_get_priv(dev);

 	return pl01x_putc(priv->regs, ch);
 }

 static int pl01x_serial_pending(struct udevice *dev, bool input)
 {
 	struct pl01x_priv *priv = dev_get_priv(dev);
 	unsigned int fr = readl(&priv->regs->fr);

 	if (input)
 		return pl01x_tstc(priv->regs);
 	else
 		return fr & UART_PL01x_FR_TXFF ? 0 : 1;
 }

 static const struct dm_serial_ops pl01x_serial_ops = {
 	.putc = pl01x_serial_putc,
 	.pending = pl01x_serial_pending,
 	.getc = pl01x_serial_getc,
 	.setbrg = pl01x_serial_setbrg,
 };

 U_BOOT_DRIVER(serial_pl01x) = {
 	.name	= "serial_pl01x",
 	.id	= UCLASS_SERIAL,
 	.probe = pl01x_serial_probe,
 	.ops	= &pl01x_serial_ops,
 	.flags = DM_FLAG_PRE_RELOC,
 };

 #endif
	/*
	* (C) Copyright 2000
	* Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
	*
	* (C) Copyright 2004
	* ARM Ltd.
	* Philippe Robin, <philippe.robin@arm.com>
	*
	* SPDX-License-Identifier: GPL-2.0+
	*/

	/* Simple U-Boot driver for the PrimeCell PL010/PL011 UARTs */

	#include <common.h>
	#include <dm.h>
	#include <errno.h>
	#include <watchdog.h>
	#include <asm/io.h>
	#include <serial.h>
	#include <dm/platform_data/serial_pl01x.h>
	#include <linux/compiler.h>
	#include "serial_pl01x_internal.h"

	#ifndef CONFIG_DM_SERIAL

	static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
	static enum pl01x_type pl01x_type __attribute__ ((section(".data")));
	static struct pl01x_regs *base_regs __attribute__ ((section(".data")));
	#define NUM_PORTS (sizeof(port)/sizeof(port[0]))

	DECLARE_GLOBAL_DATA_PTR;
	#endif

	static int pl01x_putc(struct pl01x_regs *regs, char c)
	{
	/* Wait until there is space in the FIFO */
	if (readl(&regs->fr) & UART_PL01x_FR_TXFF)
	return -EAGAIN;

	/* Send the character */
	writel(c, &regs->dr);

	return 0;
	}

	static int pl01x_getc(struct pl01x_regs *regs)
	{
	unsigned int data;

	/* Wait until there is data in the FIFO */
	if (readl(&regs->fr) & UART_PL01x_FR_RXFE)
	return -EAGAIN;

	data = readl(&regs->dr);

	/* Check for an error flag */
	if (data & 0xFFFFFF00) {
	/* Clear the error */
	writel(0xFFFFFFFF, &regs->ecr);
	return -1;
	}

	return (int) data;
	}

	static int pl01x_tstc(struct pl01x_regs *regs)
	{
	WATCHDOG_RESET();
	return !(readl(&regs->fr) & UART_PL01x_FR_RXFE);
	}

	static int pl01x_generic_serial_init(struct pl01x_regs *regs,
	enum pl01x_type type)
	{
	switch (type) {
	case TYPE_PL010:
	/* disable everything */
	writel(0, &regs->pl010_cr);
	break;
	case TYPE_PL011:
	#ifdef CONFIG_PL011_SERIAL_FLUSH_ON_INIT
	/* Empty RX fifo if necessary */
	if (readl(&regs->pl011_cr) & UART_PL011_CR_UARTEN) {
	while (!(readl(&regs->fr) & UART_PL01x_FR_RXFE))
	readl(&regs->dr);
	}
	#endif
	/* disable everything */
	writel(0, &regs->pl011_cr);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static int set_line_control(struct pl01x_regs *regs)
	{
	unsigned int lcr;
	/*
	* Internal update of baud rate register require line
	* control register write
	*/
	lcr = UART_PL011_LCRH_WLEN_8 \| UART_PL011_LCRH_FEN;
	#ifdef CONFIG_PL011_SERIAL_RLCR
	{
	int i;

	/*
	* Program receive line control register after waiting
	* 10 bus cycles. Delay be writing to readonly register
	* 10 times
	*/
	for (i = 0; i < 10; i++)
	writel(lcr, &regs->fr);

	writel(lcr, &regs->pl011_rlcr);
	}
	#endif
	writel(lcr, &regs->pl011_lcrh);
	return 0;
	}

	static int pl01x_generic_setbrg(struct pl01x_regs *regs, enum pl01x_type type,
	int clock, int baudrate)
	{
	switch (type) {
	case TYPE_PL010: {
	unsigned int divisor;

	switch (baudrate) {
	case 9600:
	divisor = UART_PL010_BAUD_9600;
	break;
	case 19200:
	divisor = UART_PL010_BAUD_9600;
	break;
	case 38400:
	divisor = UART_PL010_BAUD_38400;
	break;
	case 57600:
	divisor = UART_PL010_BAUD_57600;
	break;
	case 115200:
	divisor = UART_PL010_BAUD_115200;
	break;
	default:
	divisor = UART_PL010_BAUD_38400;
	}

	writel((divisor & 0xf00) >> 8, &regs->pl010_lcrm);
	writel(divisor & 0xff, &regs->pl010_lcrl);

	/* Finally, enable the UART */
	writel(UART_PL010_CR_UARTEN, &regs->pl010_cr);
	break;
	}
	case TYPE_PL011: {
	unsigned int temp;
	unsigned int divider;
	unsigned int remainder;
	unsigned int fraction;

	/*
	* Set baud rate
	*
	* IBRD = UART_CLK / (16 * BAUD_RATE)
	* FBRD = RND((64 * MOD(UART_CLK,(16 * BAUD_RATE)))
	* / (16 * BAUD_RATE))
	*/
	temp = 16 * baudrate;
	divider = clock / temp;
	remainder = clock % temp;
	temp = (8 * remainder) / baudrate;
	fraction = (temp >> 1) + (temp & 1);

	writel(divider, &regs->pl011_ibrd);
	writel(fraction, &regs->pl011_fbrd);

	set_line_control(regs);
	/* Finally, enable the UART */
	writel(UART_PL011_CR_UARTEN \| UART_PL011_CR_TXE \|
	UART_PL011_CR_RXE \| UART_PL011_CR_RTS, &regs->pl011_cr);
	break;
	}
	default:
	return -EINVAL;
	}

	return 0;
	}

	#ifndef CONFIG_DM_SERIAL
	static void pl01x_serial_init_baud(int baudrate)
	{
	int clock = 0;

	#if defined(CONFIG_PL010_SERIAL)
	pl01x_type = TYPE_PL010;
	#elif defined(CONFIG_PL011_SERIAL)
	pl01x_type = TYPE_PL011;
	clock = CONFIG_PL011_CLOCK;
	#endif
	base_regs = (struct pl01x_regs *)port[CONFIG_CONS_INDEX];

	pl01x_generic_serial_init(base_regs, pl01x_type);
	pl01x_generic_setbrg(base_regs, pl01x_type, clock, baudrate);
	}

	/*
	* Integrator AP has two UARTs, we use the first one, at 38400-8-N-1
	* Integrator CP has two UARTs, use the first one, at 38400-8-N-1
	* Versatile PB has four UARTs.
	*/
	int pl01x_serial_init(void)
	{
	pl01x_serial_init_baud(CONFIG_BAUDRATE);

	return 0;
	}

	static void pl01x_serial_putc(const char c)
	{
	if (c == '\n')
	while (pl01x_putc(base_regs, '\r') == -EAGAIN);

	while (pl01x_putc(base_regs, c) == -EAGAIN);
	}

	static int pl01x_serial_getc(void)
	{
	while (1) {
	int ch = pl01x_getc(base_regs);

	if (ch == -EAGAIN) {
	WATCHDOG_RESET();
	continue;
	}

	return ch;
	}
	}

	static int pl01x_serial_tstc(void)
	{
	return pl01x_tstc(base_regs);
	}

	static void pl01x_serial_setbrg(void)
	{
	/*
	* Flush FIFO and wait for non-busy before changing baudrate to avoid
	* crap in console
	*/
	while (!(readl(&base_regs->fr) & UART_PL01x_FR_TXFE))
	WATCHDOG_RESET();
	while (readl(&base_regs->fr) & UART_PL01x_FR_BUSY)
	WATCHDOG_RESET();
	pl01x_serial_init_baud(gd->baudrate);
	}

	static struct serial_device pl01x_serial_drv = {
	.name = "pl01x_serial",
	.start = pl01x_serial_init,
	.stop = NULL,
	.setbrg = pl01x_serial_setbrg,
	.putc = pl01x_serial_putc,
	.puts = default_serial_puts,
	.getc = pl01x_serial_getc,
	.tstc = pl01x_serial_tstc,
	};

	void pl01x_serial_initialize(void)
	{
	serial_register(&pl01x_serial_drv);
	}

	__weak struct serial_device *default_serial_console(void)
	{
	return &pl01x_serial_drv;
	}

	#endif /* nCONFIG_DM_SERIAL */

	#ifdef CONFIG_DM_SERIAL

	struct pl01x_priv {
	struct pl01x_regs *regs;
	enum pl01x_type type;
	};

	static int pl01x_serial_setbrg(struct udevice *dev, int baudrate)
	{
	struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
	struct pl01x_priv *priv = dev_get_priv(dev);

	pl01x_generic_setbrg(priv->regs, priv->type, plat->clock, baudrate);

	return 0;
	}

	static int pl01x_serial_probe(struct udevice *dev)
	{
	struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
	struct pl01x_priv *priv = dev_get_priv(dev);

	priv->regs = (struct pl01x_regs *)plat->base;
	priv->type = plat->type;
	return pl01x_generic_serial_init(priv->regs, priv->type);
	}

	static int pl01x_serial_getc(struct udevice *dev)
	{
	struct pl01x_priv *priv = dev_get_priv(dev);

	return pl01x_getc(priv->regs);
	}

	static int pl01x_serial_putc(struct udevice *dev, const char ch)
	{
	struct pl01x_priv *priv = dev_get_priv(dev);

	return pl01x_putc(priv->regs, ch);
	}

	static int pl01x_serial_pending(struct udevice *dev, bool input)
	{
	struct pl01x_priv *priv = dev_get_priv(dev);
	unsigned int fr = readl(&priv->regs->fr);

	if (input)
	return pl01x_tstc(priv->regs);
	else
	return fr & UART_PL01x_FR_TXFF ? 0 : 1;
	}

	static const struct dm_serial_ops pl01x_serial_ops = {
	.putc = pl01x_serial_putc,
	.pending = pl01x_serial_pending,
	.getc = pl01x_serial_getc,
	.setbrg = pl01x_serial_setbrg,
	};

	U_BOOT_DRIVER(serial_pl01x) = {
	.name = "serial_pl01x",
	.id = UCLASS_SERIAL,
	.probe = pl01x_serial_probe,
	.ops = &pl01x_serial_ops,
	.flags = DM_FLAG_PRE_RELOC,
	};

	#endif