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