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/*
* AVR power-management chip interface for the Buffalo Linkstation /
* Kurobox Platform.
*
* Author: 2006 (c) G. Liakhovetski
* g.liakhovetski@gmx.de
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of
* any kind, whether express or implied.
*/
#include <linux/workqueue.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/serial_reg.h>
#include <linux/serial_8250.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/termbits.h>
#include "mpc10x.h"
static void __iomem *avr_addr;
static unsigned long avr_clock;
static struct work_struct wd_work;
static void wd_stop(struct work_struct *unused)
{
const char string[] = "AAAAFFFFJJJJ>>>>VVVV>>>>ZZZZVVVVKKKK";
int i = 0, rescue = 8;
int len = strlen(string);
while (rescue--) {
int j;
char lsr = in_8(avr_addr + UART_LSR);
if (lsr & (UART_LSR_THRE | UART_LSR_TEMT)) {
for (j = 0; j < 16 && i < len; j++, i++)
out_8(avr_addr + UART_TX, string[i]);
if (i == len) {
/* Read "OK" back: 4ms for the last "KKKK"
plus a couple bytes back */
msleep(7);
printk("linkstation: disarming the AVR watchdog: ");
while (in_8(avr_addr + UART_LSR) & UART_LSR_DR)
printk("%c", in_8(avr_addr + UART_RX));
break;
}
}
msleep(17);
}
printk("\n");
}
#define AVR_QUOT(clock) ((clock) + 8 * 9600) / (16 * 9600)
void avr_uart_configure(void)
{
unsigned char cval = UART_LCR_WLEN8;
unsigned int quot = AVR_QUOT(avr_clock);
if (!avr_addr || !avr_clock)
return;
out_8(avr_addr + UART_LCR, cval); /* initialise UART */
out_8(avr_addr + UART_MCR, 0);
out_8(avr_addr + UART_IER, 0);
cval |= UART_LCR_STOP | UART_LCR_PARITY | UART_LCR_EPAR;
out_8(avr_addr + UART_LCR, cval); /* Set character format */
out_8(avr_addr + UART_LCR, cval | UART_LCR_DLAB); /* set DLAB */
out_8(avr_addr + UART_DLL, quot & 0xff); /* LS of divisor */
out_8(avr_addr + UART_DLM, quot >> 8); /* MS of divisor */
out_8(avr_addr + UART_LCR, cval); /* reset DLAB */
out_8(avr_addr + UART_FCR, UART_FCR_ENABLE_FIFO); /* enable FIFO */
}
void avr_uart_send(const char c)
{
if (!avr_addr || !avr_clock)
return;
out_8(avr_addr + UART_TX, c);
out_8(avr_addr + UART_TX, c);
out_8(avr_addr + UART_TX, c);
out_8(avr_addr + UART_TX, c);
}
static void __init ls_uart_init(void)
{
local_irq_disable();
#ifndef CONFIG_SERIAL_8250
out_8(avr_addr + UART_FCR, UART_FCR_ENABLE_FIFO); /* enable FIFO */
out_8(avr_addr + UART_FCR, UART_FCR_ENABLE_FIFO |
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); /* clear FIFOs */
out_8(avr_addr + UART_FCR, 0);
out_8(avr_addr + UART_IER, 0);
/* Clear up interrupts */
(void) in_8(avr_addr + UART_LSR);
(void) in_8(avr_addr + UART_RX);
(void) in_8(avr_addr + UART_IIR);
(void) in_8(avr_addr + UART_MSR);
#endif
avr_uart_configure();
local_irq_enable();
}
static int __init ls_uarts_init(void)
{
struct device_node *avr;
phys_addr_t phys_addr;
int len;
if (!machine_is(linkstation))
return 0;
avr = of_find_node_by_path("/soc10x/serial@80004500");
if (!avr)
return -EINVAL;
avr_clock = *(u32*)of_get_property(avr, "clock-frequency", &len);
phys_addr = ((u32*)of_get_property(avr, "reg", &len))[0];
if (!avr_clock || !phys_addr)
return -EINVAL;
avr_addr = ioremap(phys_addr, 32);
if (!avr_addr)
return -EFAULT;
ls_uart_init();
INIT_WORK(&wd_work, wd_stop);
schedule_work(&wd_work);
return 0;
}
late_initcall(ls_uarts_init);
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