[U-Boot-Users] [PATCH 5/6] Common serial driver for Atmel AT32 and AT91 chips

Haavard Skinnemoen hskinnemoen at atmel.com
Wed Sep 6 16:24:53 CEST 2006


This is a first attempt at creating a common serial driver for Atmel
chips. For now, it supports the AT32AP7000 AVR32 chip, but it should
be possible to support AT91RM9200 and other ARM-based chips with
some minor modifications.

There's nothing fundamentally AVR32-specific in this driver, but it
does use some features which are currently only defined for the
AT32AP CPU port:
  * pm_get_clock_freq: Obtain the clock frequency of a given domain
  * gd->console_uart: A "struct device" containing information about
    register mappings, gpio resources and clocks associated with the
    UART device.

For more information about these features, please see the "AT32AP CPU"
patch.

Although it might not seem like a huge win to consolidate the serial
driver, which is quite small and trivial, there are some general
issues we need to resolve before we can consolidate other more
complex drivers, like the ethernet and mmc drivers.

Comments are welcome.

Haavard
    
---
CHANGELOG:
	Add Atmel USART serial driver

 drivers/Makefile      |    2 
 drivers/atmel_usart.c |   88 ++++++++++++++
 drivers/atmel_usart.h |  314 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 403 insertions(+), 1 deletion(-)

Index: u-boot-1.1.4-git/drivers/Makefile
===================================================================
--- u-boot-1.1.4-git.orig/drivers/Makefile	2006-09-06 15:29:52.000000000 +0200
+++ u-boot-1.1.4-git/drivers/Makefile	2006-09-06 15:30:09.000000000 +0200
@@ -27,7 +27,7 @@ include $(TOPDIR)/config.mk
 
 LIB	= $(obj)libdrivers.a
 
-COBJS	= 3c589.o 5701rls.o ali512x.o \
+COBJS	= 3c589.o 5701rls.o ali512x.o atmel_usart.o \
 	  bcm570x.o bcm570x_autoneg.o cfb_console.o cfi_flash.o \
 	  cs8900.o ct69000.o dataflash.o dc2114x.o dm9000x.o \
 	  e1000.o eepro100.o \
Index: u-boot-1.1.4-git/drivers/atmel_usart.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ u-boot-1.1.4-git/drivers/atmel_usart.c	2006-09-06 15:29:57.000000000 +0200
@@ -0,0 +1,88 @@
+/*
+ * 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 as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include <common.h>
+
+#ifdef CONFIG_ATMEL_USART
+#include <asm/io.h>
+#include <asm/arch/platform.h>
+
+#include "atmel_usart.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+void serial_setbrg(void)
+{
+	unsigned long divisor;
+	unsigned long usart_hz;
+
+	/*
+	 *              Master Clock
+	 * Baud Rate = --------------
+	 *                16 * CD
+	 */
+	usart_hz = pm_get_clock_freq(gd->console_uart->resource[0].u.clock.id);
+	divisor = (usart_hz / 16 + gd->baudrate / 2) / gd->baudrate;
+	usart3_writel(gd->console_uart, BRGR, USART3_BF(CD, divisor));
+}
+
+int serial_init(void)
+{
+	usart3_writel(gd->console_uart, CR,
+		      USART3_BIT(RSTRX) | USART3_BIT(RSTTX));
+
+	serial_setbrg();
+
+	usart3_writel(gd->console_uart, CR,
+		      USART3_BIT(RXEN) | USART3_BIT(TXEN));
+	usart3_writel(gd->console_uart, MR,
+		      USART3_BF(USART_MODE, USART3_USART_MODE_NORMAL)
+		      | USART3_BF(USCLKS, USART3_USCLKS_MCK)
+		      | USART3_BF(CHRL, USART3_CHRL_8)
+		      | USART3_BF(PAR, USART3_PAR_NONE)
+		      | USART3_BF(NBSTOP, USART3_NBSTOP_1));
+
+	return 0;
+}
+
+void serial_putc(char c)
+{
+	if (c == '\n')
+		serial_putc('\r');
+
+	while (!(usart3_readl(gd->console_uart, CSR) & USART3_BIT(TXRDY))) ;
+	usart3_writel(gd->console_uart, THR, c);
+}
+
+void serial_puts(const char *s)
+{
+	while (*s)
+		serial_putc(*s++);
+}
+
+int serial_getc(void)
+{
+	while (!(usart3_readl(gd->console_uart, CSR) & USART3_BIT(RXRDY))) ;
+	return usart3_readl(gd->console_uart, RHR);
+}
+
+int serial_tstc(void)
+{
+	return (usart3_readl(gd->console_uart, CSR) & USART3_BIT(RXRDY)) != 0;
+}
+
+#endif /* CONFIG_ATMEL_USART */
Index: u-boot-1.1.4-git/drivers/atmel_usart.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ u-boot-1.1.4-git/drivers/atmel_usart.h	2006-09-06 15:29:57.000000000 +0200
@@ -0,0 +1,314 @@
+/*
+ * Register definitions for the Atmel USART3 module.
+ *
+ * Copyright (C) 2005-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#ifndef __DRIVERS_ATMEL_USART_H__
+#define __DRIVERS_ATMEL_USART_H__
+
+/* USART3 register offsets */
+#define USART3_CR				0x0000
+#define USART3_MR				0x0004
+#define USART3_IER				0x0008
+#define USART3_IDR				0x000c
+#define USART3_IMR				0x0010
+#define USART3_CSR				0x0014
+#define USART3_RHR				0x0018
+#define USART3_THR				0x001c
+#define USART3_BRGR				0x0020
+#define USART3_RTOR				0x0024
+#define USART3_TTGR				0x0028
+#define USART3_FIDI				0x0040
+#define USART3_NER				0x0044
+#define USART3_XXR				0x0048
+#define USART3_IFR				0x004c
+#define USART3_RPR				0x0100
+#define USART3_RCR				0x0104
+#define USART3_TPR				0x0108
+#define USART3_TCR				0x010c
+#define USART3_RNPR				0x0110
+#define USART3_RNCR				0x0114
+#define USART3_TNPR				0x0118
+#define USART3_TNCR				0x011c
+#define USART3_PTCR				0x0120
+#define USART3_PTSR				0x0124
+
+/* Bitfields in CR */
+#define USART3_RSTRX_OFFSET			2
+#define USART3_RSTRX_SIZE			1
+#define USART3_RSTTX_OFFSET			3
+#define USART3_RSTTX_SIZE			1
+#define USART3_RXEN_OFFSET			4
+#define USART3_RXEN_SIZE			1
+#define USART3_RXDIS_OFFSET			5
+#define USART3_RXDIS_SIZE			1
+#define USART3_TXEN_OFFSET			6
+#define USART3_TXEN_SIZE			1
+#define USART3_TXDIS_OFFSET			7
+#define USART3_TXDIS_SIZE			1
+#define USART3_RSTSTA_OFFSET			8
+#define USART3_RSTSTA_SIZE			1
+#define USART3_STTBRK_OFFSET			9
+#define USART3_STTBRK_SIZE			1
+#define USART3_STPBRK_OFFSET			10
+#define USART3_STPBRK_SIZE			1
+#define USART3_STTTO_OFFSET			11
+#define USART3_STTTO_SIZE			1
+#define USART3_SENDA_OFFSET			12
+#define USART3_SENDA_SIZE			1
+#define USART3_RSTIT_OFFSET			13
+#define USART3_RSTIT_SIZE			1
+#define USART3_RSTNACK_OFFSET			14
+#define USART3_RSTNACK_SIZE			1
+#define USART3_RETTO_OFFSET			15
+#define USART3_RETTO_SIZE			1
+#define USART3_DTREN_OFFSET			16
+#define USART3_DTREN_SIZE			1
+#define USART3_DTRDIS_OFFSET			17
+#define USART3_DTRDIS_SIZE			1
+#define USART3_RTSEN_OFFSET			18
+#define USART3_RTSEN_SIZE			1
+#define USART3_RTSDIS_OFFSET			19
+#define USART3_RTSDIS_SIZE			1
+#define USART3_COMM_TX_OFFSET			30
+#define USART3_COMM_TX_SIZE			1
+#define USART3_COMM_RX_OFFSET			31
+#define USART3_COMM_RX_SIZE			1
+
+/* Bitfields in MR */
+#define USART3_USART_MODE_OFFSET		0
+#define USART3_USART_MODE_SIZE			4
+#define USART3_USCLKS_OFFSET			4
+#define USART3_USCLKS_SIZE			2
+#define USART3_CHRL_OFFSET			6
+#define USART3_CHRL_SIZE			2
+#define USART3_SYNC_OFFSET			8
+#define USART3_SYNC_SIZE			1
+#define USART3_PAR_OFFSET			9
+#define USART3_PAR_SIZE				3
+#define USART3_NBSTOP_OFFSET			12
+#define USART3_NBSTOP_SIZE			2
+#define USART3_CHMODE_OFFSET			14
+#define USART3_CHMODE_SIZE			2
+#define USART3_MSBF_OFFSET			16
+#define USART3_MSBF_SIZE			1
+#define USART3_MODE9_OFFSET			17
+#define USART3_MODE9_SIZE			1
+#define USART3_CLKO_OFFSET			18
+#define USART3_CLKO_SIZE			1
+#define USART3_OVER_OFFSET			19
+#define USART3_OVER_SIZE			1
+#define USART3_INACK_OFFSET			20
+#define USART3_INACK_SIZE			1
+#define USART3_DSNACK_OFFSET			21
+#define USART3_DSNACK_SIZE			1
+#define USART3_MAX_ITERATION_OFFSET		24
+#define USART3_MAX_ITERATION_SIZE		3
+#define USART3_FILTER_OFFSET			28
+#define USART3_FILTER_SIZE			1
+
+/* Bitfields in CSR */
+#define USART3_RXRDY_OFFSET			0
+#define USART3_RXRDY_SIZE			1
+#define USART3_TXRDY_OFFSET			1
+#define USART3_TXRDY_SIZE			1
+#define USART3_RXBRK_OFFSET			2
+#define USART3_RXBRK_SIZE			1
+#define USART3_ENDRX_OFFSET			3
+#define USART3_ENDRX_SIZE			1
+#define USART3_ENDTX_OFFSET			4
+#define USART3_ENDTX_SIZE			1
+#define USART3_OVRE_OFFSET			5
+#define USART3_OVRE_SIZE			1
+#define USART3_FRAME_OFFSET			6
+#define USART3_FRAME_SIZE			1
+#define USART3_PARE_OFFSET			7
+#define USART3_PARE_SIZE			1
+#define USART3_TIMEOUT_OFFSET			8
+#define USART3_TIMEOUT_SIZE			1
+#define USART3_TXEMPTY_OFFSET			9
+#define USART3_TXEMPTY_SIZE			1
+#define USART3_ITERATION_OFFSET			10
+#define USART3_ITERATION_SIZE			1
+#define USART3_TXBUFE_OFFSET			11
+#define USART3_TXBUFE_SIZE			1
+#define USART3_RXBUFF_OFFSET			12
+#define USART3_RXBUFF_SIZE			1
+#define USART3_NACK_OFFSET			13
+#define USART3_NACK_SIZE			1
+#define USART3_RIIC_OFFSET			16
+#define USART3_RIIC_SIZE			1
+#define USART3_DSRIC_OFFSET			17
+#define USART3_DSRIC_SIZE			1
+#define USART3_DCDIC_OFFSET			18
+#define USART3_DCDIC_SIZE			1
+#define USART3_CTSIC_OFFSET			19
+#define USART3_CTSIC_SIZE			1
+#define USART3_RI_OFFSET			20
+#define USART3_RI_SIZE				1
+#define USART3_DSR_OFFSET			21
+#define USART3_DSR_SIZE				1
+#define USART3_DCD_OFFSET			22
+#define USART3_DCD_SIZE				1
+#define USART3_CTS_OFFSET			23
+#define USART3_CTS_SIZE				1
+
+/* Bitfields in RHR */
+#define USART3_RXCHR_OFFSET			0
+#define USART3_RXCHR_SIZE			9
+
+/* Bitfields in THR */
+#define USART3_TXCHR_OFFSET			0
+#define USART3_TXCHR_SIZE			9
+
+/* Bitfields in BRGR */
+#define USART3_CD_OFFSET			0
+#define USART3_CD_SIZE				16
+
+/* Bitfields in RTOR */
+#define USART3_TO_OFFSET			0
+#define USART3_TO_SIZE				16
+
+/* Bitfields in TTGR */
+#define USART3_TG_OFFSET			0
+#define USART3_TG_SIZE				8
+
+/* Bitfields in FIDI */
+#define USART3_FI_DI_RATIO_OFFSET		0
+#define USART3_FI_DI_RATIO_SIZE			11
+
+/* Bitfields in NER */
+#define USART3_NB_ERRORS_OFFSET			0
+#define USART3_NB_ERRORS_SIZE			8
+
+/* Bitfields in XXR */
+#define USART3_XOFF_OFFSET			0
+#define USART3_XOFF_SIZE			8
+#define USART3_XON_OFFSET			8
+#define USART3_XON_SIZE				8
+
+/* Bitfields in IFR */
+#define USART3_IRDA_FILTER_OFFSET		0
+#define USART3_IRDA_FILTER_SIZE			8
+
+/* Bitfields in RCR */
+#define USART3_RXCTR_OFFSET			0
+#define USART3_RXCTR_SIZE			16
+
+/* Bitfields in TCR */
+#define USART3_TXCTR_OFFSET			0
+#define USART3_TXCTR_SIZE			16
+
+/* Bitfields in RNCR */
+#define USART3_RXNCR_OFFSET			0
+#define USART3_RXNCR_SIZE			16
+
+/* Bitfields in TNCR */
+#define USART3_TXNCR_OFFSET			0
+#define USART3_TXNCR_SIZE			16
+
+/* Bitfields in PTCR */
+#define USART3_RXTEN_OFFSET			0
+#define USART3_RXTEN_SIZE			1
+#define USART3_RXTDIS_OFFSET			1
+#define USART3_RXTDIS_SIZE			1
+#define USART3_TXTEN_OFFSET			8
+#define USART3_TXTEN_SIZE			1
+#define USART3_TXTDIS_OFFSET			9
+#define USART3_TXTDIS_SIZE			1
+
+/* Constants for USART_MODE */
+#define USART3_USART_MODE_NORMAL		0
+#define USART3_USART_MODE_RS485			1
+#define USART3_USART_MODE_HARDWARE		2
+#define USART3_USART_MODE_MODEM			3
+#define USART3_USART_MODE_ISO7816_T0		4
+#define USART3_USART_MODE_ISO7816_T1		6
+#define USART3_USART_MODE_IRDA			8
+
+/* Constants for USCLKS */
+#define USART3_USCLKS_MCK			0
+#define USART3_USCLKS_MCK_DIV			1
+#define USART3_USCLKS_SCK			3
+
+/* Constants for CHRL */
+#define USART3_CHRL_5				0
+#define USART3_CHRL_6				1
+#define USART3_CHRL_7				2
+#define USART3_CHRL_8				3
+
+/* Constants for PAR */
+#define USART3_PAR_EVEN				0
+#define USART3_PAR_ODD				1
+#define USART3_PAR_SPACE			2
+#define USART3_PAR_MARK				3
+#define USART3_PAR_NONE				4
+#define USART3_PAR_MULTI			6
+
+/* Constants for NBSTOP */
+#define USART3_NBSTOP_1				0
+#define USART3_NBSTOP_1_5			1
+#define USART3_NBSTOP_2				2
+
+/* Constants for CHMODE */
+#define USART3_CHMODE_NORMAL			0
+#define USART3_CHMODE_ECHO			1
+#define USART3_CHMODE_LOCAL_LOOP		2
+#define USART3_CHMODE_REMOTE_LOOP		3
+
+/* Constants for MSBF */
+#define USART3_MSBF_LSBF			0
+#define USART3_MSBF_MSBF			1
+
+/* Constants for OVER */
+#define USART3_OVER_X16				0
+#define USART3_OVER_X8				1
+
+/* Constants for CD */
+#define USART3_CD_DISABLE			0
+#define USART3_CD_BYPASS			1
+
+/* Constants for TO */
+#define USART3_TO_DISABLE			0
+
+/* Constants for TG */
+#define USART3_TG_DISABLE			0
+
+/* Constants for FI_DI_RATIO */
+#define USART3_FI_DI_RATIO_DISABLE		0
+
+/* Bit manipulation macros */
+#define USART3_BIT(name)				\
+	(1 << USART3_##name##_OFFSET)
+#define USART3_BF(name,value)				\
+	(((value) & ((1 << USART3_##name##_SIZE) - 1))	\
+	 << USART3_##name##_OFFSET)
+#define USART3_BFEXT(name,value)			\
+	(((value) >> USART3_##name##_OFFSET)		\
+	 & ((1 << USART3_##name##_SIZE) - 1))
+#define USART3_BFINS(name,value,old)			\
+	(((old) & ~(((1 << USART3_##name##_SIZE) - 1)	\
+		    << USART3_##name##_OFFSET))		\
+	 | USART3_BF(name,value))
+
+/* Register access macros */
+#define usart3_readl(port,reg)				\
+	readl((port)->regs + USART3_##reg)
+#define usart3_writel(port,reg,value)			\
+	writel((value), (port)->regs + USART3_##reg)
+
+#endif /* __DRIVERS_ATMEL_USART_H__ */




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