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/*
* (C) Copyright 2010 Juergen Beisert - Pengutronix
*
* This code was inspired by some patches made for u-boot covered by:
* (c) 2007 Sascha Hauer <s.hauer@pengutronix.de>
* (C) Copyright 2009 Freescale Semiconductor, Inc.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/*
* Note: This is the driver for the debug UART. There is
* only one of these UARTs on the Freescale/SigmaTel parts
*/
#include <common.h>
#include <init.h>
#include <notifier.h>
#include <gpio.h>
#include <asm/io.h>
#include <mach/imx-regs.h>
#include <mach/clock.h>
#define UARTDBGDR 0x00
#define UARTDBGFR 0x18
# define TXFF (1 << 5)
# define RXFE (1 << 4)
#define UARTDBGIBRD 0x24
#define UARTDBGFBRD 0x28
#define UARTDBGLCR_H 0x2c
# define WLEN8 (3 << 5)
# define WLEN7 (2 << 5)
# define WLEN6 (1 << 5)
# define WLEN5 (0 << 5)
# define FEN (1 << 4)
#define UARTDBGCR 0x30
# define UARTEN (1 << 0)
# define TXE (1 << 8)
# define RXE (1 << 9)
#define UARTDBGIMSC 0x38
struct stm_serial_local {
struct console_device cdev;
int baudrate;
struct notifier_block notify;
};
static void stm_serial_putc(struct console_device *cdev, char c)
{
struct device_d *dev = cdev->dev;
/* Wait for room in TX FIFO */
while (readl(dev->map_base + UARTDBGFR) & TXFF)
;
writel(c, dev->map_base + UARTDBGDR);
}
static int stm_serial_tstc(struct console_device *cdev)
{
struct device_d *dev = cdev->dev;
/* Check if RX FIFO is not empty */
return !(readl(dev->map_base + UARTDBGFR) & RXFE);
}
static int stm_serial_getc(struct console_device *cdev)
{
struct device_d *dev = cdev->dev;
/* Wait while TX FIFO is empty */
while (readl(dev->map_base + UARTDBGFR) & RXFE)
;
return readl(dev->map_base + UARTDBGDR) & 0xff;
}
static void stm_serial_flush(struct console_device *cdev)
{
struct device_d *dev = cdev->dev;
/* Wait for TX FIFO empty */
while (readl(dev->map_base + UARTDBGFR) & TXFF)
;
}
static int stm_serial_setbaudrate(struct console_device *cdev, int new_baudrate)
{
struct device_d *dev = cdev->dev;
struct stm_serial_local *local = container_of(cdev, struct stm_serial_local, cdev);
uint32_t cr, lcr_h, quot;
/* Disable everything */
cr = readl(dev->map_base + UARTDBGCR);
writel(0, dev->map_base + UARTDBGCR);
/* Calculate and set baudrate */
quot = (imx_get_xclk() * 4000) / new_baudrate;
writel(quot & 0x3f, dev->map_base + UARTDBGFBRD);
writel(quot >> 6, dev->map_base + UARTDBGIBRD);
/* Set 8n1 mode, enable FIFOs */
lcr_h = WLEN8 | FEN;
writel(lcr_h, dev->map_base + UARTDBGLCR_H);
/* Re-enable debug UART */
writel(cr, dev->map_base + UARTDBGCR);
local->baudrate = new_baudrate;
return 0;
}
static int stm_clocksource_clock_change(struct notifier_block *nb, unsigned long event, void *data)
{
struct stm_serial_local *local = container_of(nb, struct stm_serial_local, notify);
return stm_serial_setbaudrate(&local->cdev, local->baudrate);
}
static int stm_serial_init_port(struct console_device *cdev)
{
struct device_d *dev = cdev->dev;
/*
* If the board specific file registers this console we should force
* the usage of the debug UART pins, to be able to let the user see
* the output, even if the board file forgets to configure these pins.
*/
imx_gpio_mode(PWM1_DUART_TX);
imx_gpio_mode(PWM0_DUART_RX);
/* Disable UART */
writel(0, dev->map_base + UARTDBGCR);
/* Mask interrupts */
writel(0, dev->map_base + UARTDBGIMSC);
return 0;
}
static struct stm_serial_local stm_device = {
.cdev = {
.f_caps = CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR,
.tstc = stm_serial_tstc,
.putc = stm_serial_putc,
.getc = stm_serial_getc,
.flush = stm_serial_flush,
.setbrg = stm_serial_setbaudrate,
},
};
static int stm_serial_probe(struct device_d *dev)
{
stm_device.cdev.dev = dev;
dev->type_data = &stm_device.cdev;
stm_serial_init_port(&stm_device.cdev);
stm_serial_setbaudrate(&stm_device.cdev, CONFIG_BAUDRATE);
/* Enable UART */
writel(TXE | RXE | UARTEN, dev->map_base + UARTDBGCR);
console_register(&stm_device.cdev);
stm_device.notify.notifier_call = stm_clocksource_clock_change;
clock_register_client(&stm_device.notify);
return 0;
}
static void stm_serial_remove(struct device_d *dev)
{
struct console_device *cdev = dev->type_data;
stm_serial_flush(cdev);
}
static struct driver_d stm_serial_driver = {
.name = "stm_serial",
.probe = stm_serial_probe,
.remove = stm_serial_remove,
};
static int stm_serial_init(void)
{
register_driver(&stm_serial_driver);
return 0;
}
console_initcall(stm_serial_init);
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