Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * 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);