[U-Boot-Users] [Patch 09/17 Try 2] U-Boot-V2:Serial: Add support for NS16550 Driver
Menon, Nishanth
x0nishan at ti.com
Wed Jun 4 07:05:56 CEST 2008
Sascha,
> -----Original Message-----
> From: Sascha Hauer [mailto:s.hauer at pengutronix.de]
> Sent: Tuesday, June 03, 2008 12:47 PM
> To: Menon, Nishanth
> Cc: u-boot-users at lists.sourceforge.net; Laurent Desnogues; dirk.behme at googlemail.com;
> philip.balister at gmail.com; Gopinath, Thara; Kamat, Nishant; Syed Mohammed, Khasim
> Subject: Re: [Patch 09/17] U-Boot-V2:Serial: Add support for NS16550Driver.`
>
> What I meant is that you should put the access functions itself into
> platform_data, not a description of their register size / padding.
> That way each board can decide which funky access functions it needs, be
> it that the 16550 is connected via SPI, memory io or whatever.
Try 2 of the patch.
Signed-off-by: Nishanth Menon<x0nishan at ti.com>
---
drivers/serial/Kconfig | 13 ++
drivers/serial/Makefile | 1
drivers/serial/serial_ns16550.c | 252 ++++++++++++++++++++++++++++++++++++++++
drivers/serial/serial_ns16550.h | 98 +++++++++++++++
include/ns16550.h | 55 ++++++++
5 files changed, 419 insertions(+)
Index: u-boot.v2/drivers/serial/Kconfig
===================================================================
--- u-boot.v2.orig/drivers/serial/Kconfig 2008-06-03 22:42:07.000000000 -0500
+++ u-boot.v2/drivers/serial/Kconfig 2008-06-03 22:46:07.000000000 -0500
@@ -24,4 +24,17 @@
depends on BLACKFIN
default y
bool "Blackfin serial driver"
+
+config DRIVER_SERIAL_NS16550
+ default n
+ bool "NS16550 serial driver"
+ help
+ Enable this to get support for NS16550 based serial devices
+
+config DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
+ bool "OMAP Extensions for NS16550"
+ depends on DRIVER_SERIAL_NS16550
+ depends on ARCH_OMAP
+ help
+ Say Y here if you are using OMAP extensions to NS16550
endmenu
Index: u-boot.v2/drivers/serial/Makefile
===================================================================
--- u-boot.v2.orig/drivers/serial/Makefile 2008-06-03 22:42:06.000000000 -0500
+++ u-boot.v2/drivers/serial/Makefile 2008-06-03 22:46:07.000000000 -0500
@@ -10,3 +10,4 @@
obj-$(CONFIG_DRIVER_SERIAL_LINUX_COMSOLE) += linux_console.o
obj-$(CONFIG_DRIVER_SERIAL_MPC5XXX) += serial_mpc5xxx.o
obj-$(CONFIG_DRIVER_SERIAL_BLACKFIN) += serial_blackfin.o
+obj-$(CONFIG_DRIVER_SERIAL_NS16550) += serial_ns16550.o
Index: u-boot.v2/drivers/serial/serial_ns16550.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ u-boot.v2/drivers/serial/serial_ns16550.c 2008-06-03 22:46:32.000000000 -0500
@@ -0,0 +1,252 @@
+/**
+ * @file
+ * @brief NS16550 Driver implementation
+ *
+ * FileName: drivers/serial/serial_ns16550.c
+ *
+ * NS16550 support
+ * Modified from U-Boot V1 drivers/serial.c and drivers/ns16550.c
+ * originally from linux source (arch/ppc/boot/ns16550.c)
+ * modified to use CFG_ISA_MEM and new defines
+ */
+/*
+ * (C) Copyright 2008
+ * Texas Instruments, <www.ti.com>
+ * Nishanth Menon <x0nishan at ti.com>
+ *
+ * (C) Copyright 2000
+ * Rob Taylor, Flying Pig Systems. robt at flyingpig.com.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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>
+#include <driver.h>
+#include <init.h>
+#include <errno.h>
+#include <malloc.h>
+#include <asm/io.h>
+
+#include "serial_ns16550.h"
+#include <ns16550.h>
+
+/*********** Private Functions **********************************/
+
+/**
+ * @brief ns16550_calc_divisor - compute the divisor for a baud rate
+ *
+ * @param[in] cdev - pointer to console device
+ * @param[in] baudrate - baud rate
+ *
+ * @return divisor to be set
+ */
+static unsigned int ns16550_calc_divisor(struct console_device *cdev,
+ unsigned int baudrate)
+{
+ struct NS16550_plat *plat = (struct NS16550_plat *)
+ cdev->dev->platform_data;
+ unsigned int clk = plat->clock;
+#ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
+ /* FIXME: Legacy Code copied from U-Boot V1 implementation
+ */
+#ifdef CONFIG_ARCH_OMAP1510
+ unsigned long base = cdev->dev->map_base;
+ /* If can't cleanly clock 115200 set div to 1 */
+ if ((clk == 12000000) && (baudrate == 115200)) {
+ /* enable 6.5 * divisor */
+ plat->reg_write(OSC_12M_SEL, base, osc_12m_sel);
+ return 1; /* return 1 for base divisor */
+ }
+ /* clear if previously set */
+ plat->reg_write(0, base, osc_12m_sel);
+#elif defined(CONFIG_ARCH_OMAP1610)
+ /* If can't cleanly clock 115200 set div to 1 */
+ if ((clk == 48000000) && (baudrate == 115200))
+ return 26; /* return 26 for base divisor */
+#endif
+
+#endif /* End of OMAP specific handling */
+ return (clk / MODE_X_DIV / baudrate);
+
+}
+
+/**
+ * @brief ns16550_serial_init_port - initialize the device
+ *
+ * @param cdev[in] - pointer to console device
+ */
+static void ns16550_serial_init_port(struct console_device *cdev)
+{
+ struct NS16550_plat *plat = (struct NS16550_plat *)
+ cdev->dev->platform_data;
+ unsigned long base = cdev->dev->map_base;
+ unsigned int baud_divisor;
+
+ /* Setup the serial port with the defaults first */
+ baud_divisor = ns16550_calc_divisor(cdev, CONFIG_BAUDRATE);
+
+ /* initializing the device for the first time */
+ plat->reg_write(0x00, base, ier);
+#ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
+ plat->reg_write(0x07, base, mdr1); /* Disable */
+#endif
+ plat->reg_write(LCR_BKSE | LCRVAL, base, lcr);
+ plat->reg_write(baud_divisor & 0xFF, base, dll);
+ plat->reg_write((baud_divisor >> 8) & 0xff, base, dlm);
+ plat->reg_write(LCRVAL, base, lcr);
+ plat->reg_write(MCRVAL, base, mcr);
+ plat->reg_write(FCRVAL, base, fcr);
+#ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
+ plat->reg_write(0x00, base, mdr1);
+#endif
+}
+
+/*********** Exposed Functions **********************************/
+
+/**
+ * @brief ns16550_putc- put a character to the serial port
+ *
+ * @param cdev[in] - pointer to console device
+ * @param c[in] - character to put
+ */
+static void ns16550_putc(struct console_device *cdev, char c)
+{
+ struct NS16550_plat *plat = (struct NS16550_plat *)
+ cdev->dev->platform_data;
+ unsigned long base = cdev->dev->map_base;
+ /* Loop Doing Nothing */
+ while ((plat->reg_read(base, lsr) & LSR_THRE) == 0) ;
+ plat->reg_write(c, base, thr);
+}
+
+/**
+ * @brief ns16550_getc - retrieve a character from serial port
+ *
+ * @param cdev[in] - pointer to console device
+ *
+ * @return return the character read
+ */
+static int ns16550_getc(struct console_device *cdev)
+{
+ struct NS16550_plat *plat = (struct NS16550_plat *)
+ cdev->dev->platform_data;
+ unsigned long base = cdev->dev->map_base;
+ /* Loop Doing Nothing */
+ while ((plat->reg_read(base, lsr) & LSR_DR) == 0) ;
+ return plat->reg_read(base, rbr);
+}
+
+/**
+ * @brief ns16550_tstc - test if character is available
+ *
+ * @param cdev[in] -pointer to console device
+ *
+ * @return - status based on data availability
+ */
+static int ns16550_tstc(struct console_device *cdev)
+{
+ struct NS16550_plat *plat = (struct NS16550_plat *)
+ cdev->dev->platform_data;
+ unsigned long base = cdev->dev->map_base;
+ return ((plat->reg_read(base, lsr) & LSR_DR) != 0);
+}
+
+/**
+ * @brief ns16550_setbaudrate - set the baudrate for the uart port
+ *
+ * @param cdev[in] - console device
+ * @param baud_rate[in] - baud rate to set
+ *
+ * @return 0-implied to support the baudrate
+ */
+static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
+{
+ struct NS16550_plat *plat = (struct NS16550_plat *)
+ cdev->dev->platform_data;
+ unsigned long base = cdev->dev->map_base;
+ unsigned int baud_divisor = ns16550_calc_divisor(cdev, baud_rate);
+ plat->reg_write(0x00, base, ier);
+ plat->reg_write(LCR_BKSE, base, lcr);
+ plat->reg_write(baud_divisor & 0xff, base, dll);
+ plat->reg_write((baud_divisor >> 8) & 0xff, base, dlm);
+ plat->reg_write(LCRVAL, base, lcr);
+ plat->reg_write(MCRVAL, base, mcr);
+ plat->reg_write(FCRVAL, base, fcr);
+ return 0;
+}
+
+/**
+ * @brief ns16550_probe - Probe entry point -called on the first
+ * match for device
+ *
+ * @param dev[in] - matched device
+ *
+ * @return EINVAL if platform_data is not populated,
+ * ENOMEM if calloc failed
+ * else return result of console_register
+ */
+static int ns16550_probe(struct device_d *dev)
+{
+ struct console_device *cdev;
+ struct NS16550_plat *plat = (struct NS16550_plat *)dev->platform_data;
+
+ /* we do expect platform specific data */
+ if (plat == NULL)
+ return -EINVAL;
+ if (plat->reg_read == NULL)
+ return -EINVAL;
+ if (plat->reg_write == NULL)
+ return -EINVAL;
+ cdev = calloc(1, sizeof(struct console_device));
+ if (cdev == NULL)
+ return -ENOMEM;
+
+ dev->type_data = cdev;
+ cdev->dev = dev;
+ cdev->f_caps = plat->f_caps;
+ cdev->tstc = ns16550_tstc;
+ cdev->putc = ns16550_putc;
+ cdev->getc = ns16550_getc;
+ cdev->setbrg = ns16550_setbaudrate;
+
+ ns16550_serial_init_port(cdev);
+
+ return console_register(cdev);
+}
+
+/**
+ * @brief Driver registration structure
+ */
+static struct driver_d ns16550_serial_driver = {
+ .name = "serial_ns16550",
+ .probe = ns16550_probe,
+ .type = DEVICE_TYPE_CONSOLE,
+};
+
+/**
+ * @brief ns16550_serial_init - driver initialization function
+ *
+ * @return result of register_driver
+ */
+static int ns16550_serial_init(void)
+{
+ return register_driver(&ns16550_serial_driver);
+}
+
+console_initcall(ns16550_serial_init);
Index: u-boot.v2/drivers/serial/serial_ns16550.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ u-boot.v2/drivers/serial/serial_ns16550.h 2008-06-03 22:46:07.000000000 -0500
@@ -0,0 +1,98 @@
+/**
+ * @file
+ * @brief Serial NS16550 header
+ *
+ * FileName: drivers/serial/serial_ns16550.h
+ *
+ * @code struct NS16550 @endcode
+ * Register definitions for NS16550 device
+ */
+/*
+ * 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.
+ *
+ * NS16550 Serial Port
+ * originally from linux source (arch/ppc/boot/ns16550.h)
+ * modified slightly to
+ * have addresses as offsets from CFG_ISA_BASE
+ * added a few more definitions
+ * added prototypes for ns16550.c
+ * reduced no of com ports to 2
+ * modifications (c) Rob Taylor, Flying Pig Systems. 2000.
+ *
+ * added support for port on 64-bit bus
+ * by Richard Danter (richard.danter at windriver.com), (C) 2005 Wind River Systems
+ */
+
+#ifndef __SERIAL_NS16550__H
+#define __SERIAL_NS16550__H
+
+/** Register offset definitions
+ * platform implementation needs to translate this
+ */
+#define rbr 0
+#define ier 1
+#define fcr 2
+#define lcr 3
+#define mcr 4
+#define lsr 5
+#define msr 6
+#define scr 7
+#ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
+#define mdr1 8
+#define osc_12m_sel 9
+#endif
+
+#define thr rbr
+#define iir fcr
+#define dll rbr
+#define dlm ier
+
+#define FCR_FIFO_EN 0x01 /* Fifo enable */
+#define FCR_RXSR 0x02 /* Receiver soft reset */
+#define FCR_TXSR 0x04 /* Transmitter soft reset */
+
+#define MCR_DTR 0x01
+#define MCR_RTS 0x02
+#define MCR_DMA_EN 0x04
+#define MCR_TX_DFR 0x08
+
+#define LCR_WLS_MSK 0x03 /* character length select mask */
+#define LCR_WLS_5 0x00 /* 5 bit character length */
+#define LCR_WLS_6 0x01 /* 6 bit character length */
+#define LCR_WLS_7 0x02 /* 7 bit character length */
+#define LCR_WLS_8 0x03 /* 8 bit character length */
+/* Number of stop Bits, off = 1, on = 1.5 or 2) */
+#define LCR_STB 0x04
+#define LCR_PEN 0x08 /* Parity eneble */
+#define LCR_EPS 0x10 /* Even Parity Select */
+#define LCR_STKP 0x20 /* Stick Parity */
+#define LCR_SBRK 0x40 /* Set Break */
+#define LCR_BKSE 0x80 /* Bank select enable */
+
+#define LSR_DR 0x01 /* Data ready */
+#define LSR_OE 0x02 /* Overrun */
+#define LSR_PE 0x04 /* Parity error */
+#define LSR_FE 0x08 /* Framing error */
+#define LSR_BI 0x10 /* Break */
+#define LSR_THRE 0x20 /* Xmit holding register empty */
+#define LSR_TEMT 0x40 /* Xmitter empty */
+#define LSR_ERR 0x80 /* Error */
+
+#ifdef CONFIG_ARCH_OMAP1510
+#define OSC_12M_SEL 0x01 /* selects 6.5 * current clk div */
+#endif
+
+/* useful defaults for LCR */
+#define LCR_8N1 0x03
+
+#define LCRVAL LCR_8N1 /* 8 data, 1 stop, no parity */
+#define MCRVAL (MCR_DTR | MCR_RTS) /* RTS/DTR */
+/* Clear & enable FIFOs */
+#define FCRVAL (FCR_FIFO_EN | FCR_RXSR | FCR_TXSR)
+
+#define MODE_X_DIV 16
+
+#endif /* __SERIAL_NS16550__H */
Index: u-boot.v2/include/ns16550.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ u-boot.v2/include/ns16550.h 2008-06-03 22:46:07.000000000 -0500
@@ -0,0 +1,55 @@
+/**
+ * @file
+ * @brief Serial NS16550 platform specific header
+ *
+ * FileName: include/ns16550.h
+ * @code struct NS16550_plat @endcode
+ * represents The specifics of the device present in the system.
+ */
+/*
+ * (C) Copyright 2008
+ * Texas Instruments, <www.ti.com>
+ * Nishanth Menon <x0nishan at ti.com>
+ *
+ * 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 __NS16650_PLATFORM_H_
+#define __NS16650_PLATFORM_H_
+
+/**
+ * @brief Platform dependent feature:
+ * Pass pointer to this structure as part of device_d -> platform_data
+ */
+struct NS16550_plat {
+ /** Clock speed */
+ unsigned int clock;
+ /** Console capabilities:
+ * CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR @see console.h
+ */
+ unsigned char f_caps;
+ /**
+ * register read access capability
+ */
+ unsigned int (*reg_read) (unsigned long base, unsigned char reg_offset);
+ /**
+ * register write access capability
+ */
+ void (*reg_write) (unsigned int val, unsigned long base,
+ unsigned char reg_offset);
+};
+
+#endif /* __NS16650_PLATFORM_H_ */
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