path: root/packages/linux/linux-2.6.18/atmel-usart3-driver.patch

From nobody Mon Sep 17 00:00:00 2001
From: Håvard Skinnemoen <hskinnemoen@atmel.com>
Date: Fri Nov 18 16:31:34 2005 +0100
Subject: [PATCH] AVR32: USART3 Serial Driver

---

 drivers/serial/Kconfig       |   21 
 drivers/serial/Makefile      |    1 
 drivers/serial/atmel_usart.c | 1086 +++++++++++++++++++++++++++++++++++++++++++
 drivers/serial/atmel_usart.h |  290 +++++++++++
 4 files changed, 1398 insertions(+)

Index: linux-2.6.18-avr32/drivers/serial/Kconfig
===================================================================
--- linux-2.6.18-avr32.orig/drivers/serial/Kconfig	2006-11-02 14:16:07.000000000 +0100
+++ linux-2.6.18-avr32/drivers/serial/Kconfig	2006-11-02 15:54:18.000000000 +0100
@@ -246,6 +246,27 @@ config SERIAL_8250_AU1X00
 
 comment "Non-8250 serial port support"
 
+config SERIAL_ATMEL
+	tristate "Atmel USART3 serial port support"
+	depends on AVR32
+	select SERIAL_CORE
+	default y
+	help
+	  Support for the Atmel USART3 on-chip USART found in most
+	  AT32 and AT91 parts from Atmel.
+
+	  If unsure, say Y.
+
+config SERIAL_ATMEL_CONSOLE
+	bool "Support for console on Atmel USART3 serial port"
+	depends on SERIAL_ATMEL=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Say Y here if you wish to use an Atmel USART3 serial port as
+	  the system console (the system console is the device which
+	  receives all kernel messages and warnings and which allows
+	  logins in single user mode).
+
 config SERIAL_AMBA_PL010
 	tristate "ARM AMBA PL010 serial port support"
 	depends on ARM_AMBA && (BROKEN || !ARCH_VERSATILE)
Index: linux-2.6.18-avr32/drivers/serial/Makefile
===================================================================
--- linux-2.6.18-avr32.orig/drivers/serial/Makefile	2006-11-02 14:16:07.000000000 +0100
+++ linux-2.6.18-avr32/drivers/serial/Makefile	2006-11-02 14:17:29.000000000 +0100
@@ -20,6 +20,7 @@ obj-$(CONFIG_SERIAL_8250_BOCA) += 8250_b
 obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o
 obj-$(CONFIG_SERIAL_8250_MCA) += 8250_mca.o
 obj-$(CONFIG_SERIAL_8250_AU1X00) += 8250_au1x00.o
+obj-$(CONFIG_SERIAL_ATMEL) += atmel_usart.o
 obj-$(CONFIG_SERIAL_AMBA_PL010) += amba-pl010.o
 obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o
 obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o
Index: linux-2.6.18-avr32/drivers/serial/atmel_usart.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.18-avr32/drivers/serial/atmel_usart.c	2006-11-02 15:54:18.000000000 +0100
@@ -0,0 +1,1086 @@
+/*
+ * Driver for Atmel USART3 Serial ports
+ *
+ * Based on AT91RM9200 serial driver by Rick Bronson
+ * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ * Based on drivers/serial/sa1100.c by Deep Blue Solutions Ltd.
+ *
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/dma-mapping.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/serial.h>
+#include <linux/tty.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+
+#include <asm/arch/board.h>
+
+#if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#include <linux/sysrq.h>
+#endif
+
+#include <linux/serial_core.h>
+
+#include "atmel_usart.h"
+
+/*
+ * TODO: Move this definition into linux/serial_core.h
+ */
+#define PORT_USART3		60
+
+/*
+ * Use the same major/minor numbers as the AT91 USART, which is
+ * actually the same chip
+ */
+#define SERIAL_USART3_MAJOR	TTY_MAJOR
+#define MINOR_START		64
+#define NR_PORTS		4
+
+#define ERROR_FLAGS		(USART3_BIT(CSR_PARE)		\
+				 | USART3_BIT(CSR_FRAME)	\
+				 | USART3_BIT(CSR_OVRE))
+
+/* Must be a power of two, or everything will break */
+#define RX_BUFFER_SIZE		32
+struct usart3_port {
+	void __iomem *regs;
+	int break_active;
+	unsigned int tx_dma_head;
+	int rx_tail;
+	char *rx_buffer;
+	dma_addr_t rx_dma;
+	dma_addr_t tx_dma;
+	struct clk *mck;
+	unsigned long mapsize;
+	struct uart_port uart;
+};
+#define to_usart3_port(port) container_of(port, struct usart3_port, uart)
+
+static void tx_dma_sync(struct uart_port *port)
+{
+	struct usart3_port *up = to_usart3_port(port);
+	struct circ_buf *xmit = &port->info->xmit;
+
+	if (xmit->head < up->tx_dma_head) {
+		dma_sync_single_for_device(port->dev,
+					   up->tx_dma + up->tx_dma_head,
+					   UART_XMIT_SIZE - up->tx_dma_head,
+					   DMA_TO_DEVICE);
+		dma_sync_single_for_device(port->dev, up->tx_dma,
+					   xmit->head, DMA_TO_DEVICE);
+	} else {
+		dma_sync_single_for_device(port->dev,
+					   up->tx_dma + up->tx_dma_head,
+					   xmit->head - up->tx_dma_head,
+					   DMA_TO_DEVICE);
+	}
+}
+
+static void tx_dma_update_tail(struct uart_port *port)
+{
+	struct usart3_port *up = to_usart3_port(port);
+	struct circ_buf *xmit = &port->info->xmit;
+	unsigned long status, remaining;
+	unsigned int new_tail;
+
+	/* Account for the characters DMA'ed since last update */
+	remaining = usart3_readl(up, TCR);
+
+	if (up->tx_dma_head < xmit->tail) {
+		/*
+		 * We have wrapped around, and there's a chunk at the
+		 * beginning of the buffer that has been submitted for
+		 * DMA.  If the ENDTX bit is set, it means that the
+		 * DMA controller also has wrapped around and copied
+		 * TNPR/TNCR into TPR/TCR.
+		 */
+		status = usart3_readl(up, CSR);
+		BUG_ON((up->tx_dma_head != 0)
+		       && (usart3_readl(up, TNCR) == 0)
+		       && !(status & USART3_BIT(ENDTX)));
+		if (status & USART3_BIT(ENDTX)) {
+			BUG_ON(usart3_readl(up, TNCR) != 0);
+
+			/* The ENDTX bit might be set after we read TCR */
+			remaining = usart3_readl(up, TCR);
+
+			usart3_writel(up, TNCR, 0);
+			port->icount.tx += UART_XMIT_SIZE - xmit->tail;
+			xmit->tail = 0;
+
+			BUG_ON(remaining > up->tx_dma_head);
+			new_tail = up->tx_dma_head - remaining;
+		} else {
+			/*
+			 * The DMA controller hasn't switched yet, so
+			 * TCR indicates the number of bytes left
+			 * until this happens.
+			 */
+			new_tail = UART_XMIT_SIZE - remaining;
+		}
+	} else {
+		/* No wraparound, move the tail closer to dma_head. */