linux/arch/arm/mach-davinci/serial.c

/*
 * TI DaVinci serial driver
 *
 * Copyright (C) 2006 Texas Instruments.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
 * GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <asm/irq.h>
#include <mach/hardware.h>
#include <mach/serial.h>
#include <mach/irqs.h>
#include <mach/cputype.h>
#include "clock.h"

static inline unsigned int serial_read_reg(struct plat_serial8250_port *up,
					   int offset)
{
	offset <<= up->regshift;
	return (unsigned int)__raw_readl(IO_ADDRESS(up->mapbase) + offset);
}

static inline void serial_write_reg(struct plat_serial8250_port *p, int offset,
				    int value)
{
	offset <<= p->regshift;
	__raw_writel(value, IO_ADDRESS(p->mapbase) + offset);
}

static struct plat_serial8250_port serial_platform_data[] = {
	{
		.mapbase	= DAVINCI_UART0_BASE,
		.irq		= IRQ_UARTINT0,
		.flags		= UPF_BOOT_AUTOCONF | UPF_SKIP_TEST |
				  UPF_IOREMAP,
		.iotype		= UPIO_MEM,
		.regshift	= 2,
	},
	{
		.mapbase	= DAVINCI_UART1_BASE,
		.irq		= IRQ_UARTINT1,
		.flags		= UPF_BOOT_AUTOCONF | UPF_SKIP_TEST |
				  UPF_IOREMAP,
		.iotype		= UPIO_MEM,
		.regshift	= 2,
	},
	{
		.mapbase	= DAVINCI_UART2_BASE,
		.irq		= IRQ_UARTINT2,
		.flags		= UPF_BOOT_AUTOCONF | UPF_SKIP_TEST |
				  UPF_IOREMAP,
		.iotype		= UPIO_MEM,
		.regshift	= 2,
	},
	{
		.flags		= 0
	},
};

static struct platform_device serial_device = {
	.name			= "serial8250",
	.id			= PLAT8250_DEV_PLATFORM,
	.dev			= {
		.platform_data	= serial_platform_data,
	},
};

static void __init davinci_serial_reset(struct plat_serial8250_port *p)
{
	unsigned int pwremu = 0;

	serial_write_reg(p, UART_IER, 0);  /* disable all interrupts */

	/* reset both transmitter and receiver: bits 14,13 = UTRST, URRST */
	serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu);
	mdelay(10);

	pwremu |= (0x3 << 13);
	pwremu |= 0x1;
	serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu);

	if (cpu_is_davinci_dm646x())
		serial_write_reg(p, UART_DM646X_SCR,
				 UART_DM646X_SCR_TX_WATERMARK);
}

void __init davinci_serial_init(struct davinci_uart_config *info)
{
	int i;
	char name[16];
	struct clk *uart_clk;
	struct device *dev = &serial_device.dev;

	/*
	 * Make sure the serial ports are muxed on at this point.
	 * You have to mux them off in device drivers later on
	 * if not needed.
	 */
	for (i = 0; i < DAVINCI_MAX_NR_UARTS; i++) {
		struct plat_serial8250_port *p = serial_platform_data + i;

		if (!(info->enabled_uarts & (1 << i))) {
			p->flags = 0;
			continue;
		}

		if (cpu_is_davinci_dm646x())
			p->iotype = UPIO_MEM32;

		if (cpu_is_davinci_dm355()) {
			if (i == 2) {
				p->mapbase = (unsigned long)DM355_UART2_BASE;
				p->irq = IRQ_DM355_UARTINT2;
			}
		}

		sprintf(name, "uart%d", i);
		uart_clk = clk_get(dev, name);
		if (IS_ERR(uart_clk))
			printk(KERN_ERR "%s:%d: failed to get UART%d clock\n",
					__func__, __LINE__, i);
		else {
			clk_enable(uart_clk);
			p->uartclk = clk_get_rate(uart_clk);
			davinci_serial_reset(p);
		}
	}
}

static int __init davinci_init(void)
{
	return platform_device_register(&serial_device);
}

arch_initcall(davinci_init);