1 files changed, 147 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/embedded6xx/ls_uart.c b/arch/powerpc/platforms/embedded6xx/ls_uart.c
new file mode 100644
index 000000000..6c1dbf8ae
--- /dev/null
+++ b/arch/powerpc/platforms/embedded6xx/ls_uart.c
@@ -0,0 +1,147 @@
+/*
+ * 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 <linux/of.h>
+#include <linux/of_address.h>
+#include <asm/io.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;
+	struct resource res;
+	int len, ret;
+
+	avr = of_find_node_by_path("/soc10x/serial@80004500");
+	if (!avr)
+		return -EINVAL;
+
+	avr_clock = *(u32*)of_get_property(avr, "clock-frequency", &len);
+	if (!avr_clock)
+		return -EINVAL;
+
+	ret = of_address_to_resource(avr, 0, &res);
+	if (ret)
+		return ret;
+
+	of_node_put(avr);
+
+	avr_addr = ioremap(res.start, 32);
+	if (!avr_addr)
+		return -EFAULT;
+
+	ls_uart_init();
+
+	INIT_WORK(&wd_work, wd_stop);
+	schedule_work(&wd_work);
+
+	return 0;
+}
+
+machine_late_initcall(linkstation, ls_uarts_init);