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barebox/drivers/serial/serial_auart.c

236 lines
6.4 KiB
C

/*
* (C) 2013 Marc Kleine-Budde <mkl@pengutronix.de>
*
* Based on the stm-serial driver:
*
* (C) Copyright 2010 Juergen Beisert - Pengutronix
*
* ...also based on the u-boot auart driver:
*
* (C) 2011 Wolfgang Ocker <weo@reccoware.de>
*
* Based on the standard DUART serial driver:
*
* (C) 2007 Sascha Hauer <s.hauer@pengutronix.de>
*
* (C) Copyright 2009-2010 Freescale Semiconductor, Inc.
*
* Further based on the Linux mxs-auart.c driver:
*
* Freescale STMP37XX/STMP378X Application UART driver
*
* Author: dmitry pervushin <dimka@embeddedalley.com>
*
* Copyright 2008-2010 Freescale Semiconductor, Inc.
* Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
*
* 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.
*
*/
#include <common.h>
#include <gpio.h>
#include <init.h>
#include <io.h>
#include <malloc.h>
#include <notifier.h>
#include <stmp-device.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <mach/clock.h>
#include <mach/imx-regs.h>
#define HW_UARTAPP_CTRL0 (0x00000000)
#define HW_UARTAPP_CTRL2 (0x00000020)
#define HW_UARTAPP_CTRL2_SET (0x00000024)
#define HW_UARTAPP_CTRL2_CLR (0x00000028)
#define BM_UARTAPP_CTRL2_CTSEN (0x00008000)
#define BM_UARTAPP_CTRL2_RTSEN (0x00004000)
#define BM_UARTAPP_CTRL2_RXE (0x00000200)
#define BM_UARTAPP_CTRL2_TXE (0x00000100)
#define BM_UARTAPP_CTRL2_USE_LCR2 (0x00000040)
#define BM_UARTAPP_CTRL2_UARTEN (0x00000001)
#define HW_UARTAPP_LINECTRL (0x00000030)
#define BM_UARTAPP_LINECTRL_FEN (0x00000010)
#define BM_UARTAPP_LINECTRL_BAUD_DIVFRAC (0x00003F00)
#define BF_UARTAPP_LINECTRL_BAUD_DIVFRAC(v) \
(((v) << 8) & BM_UARTAPP_LINECTRL_BAUD_DIVFRAC)
#define BP_UARTAPP_LINECTRL_BAUD_DIVINT (16)
#define BM_UARTAPP_LINECTRL_BAUD_DIVINT (0xFFFF0000)
#define BF_UARTAPP_LINECTRL_BAUD_DIVINT(v) \
(((v) << 16) & BM_UARTAPP_LINECTRL_BAUD_DIVINT)
#define BP_UARTAPP_LINECTRL_WLEN (5)
#define BM_UARTAPP_LINECTRL_WLEN (0x00000060)
#define BF_UARTAPP_LINECTRL_WLEN(v) \
(((v) << 5) & BM_UARTAPP_LINECTRL_WLEN)
#define HW_UARTAPP_LINECTRL2_SET (0x00000044)
#define HW_UARTAPP_INTR (0x00000050)
#define HW_UARTAPP_DATA (0x00000060)
#define BM_UARTAPP_STAT_RXFE (0x01000000)
#define BM_UARTAPP_STAT_TXFE (0x08000000)
#define HW_UARTAPP_STAT (0x00000070)
#define BM_UARTAPP_STAT_TXFF (0x02000000)
struct auart_priv {
struct console_device cdev;
int baudrate;
struct notifier_block notify;
void __iomem *base;
struct clk *clk;
};
static void auart_serial_putc(struct console_device *cdev, char c)
{
struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
/* Wait for room in TX FIFO */
while (readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_TXFF)
;
writel(c, priv->base + HW_UARTAPP_DATA);
}
static int auart_serial_tstc(struct console_device *cdev)
{
struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
/* Check if RX FIFO is not empty */
return !(readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_RXFE);
}
static int auart_serial_getc(struct console_device *cdev)
{
struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
/* Wait while RX FIFO is empty */
while (!auart_serial_tstc(cdev))
;
return readl(priv->base + HW_UARTAPP_DATA) & 0xff;
}
static void auart_serial_flush(struct console_device *cdev)
{
struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
/* Wait for TX FIFO empty */
while (!(readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_TXFE))
;
}
static int auart_serial_setbaudrate(struct console_device *cdev, int new_baudrate)
{
struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
uint32_t ctrl2, quot, reg;
/* Disable everything */
ctrl2 = readl(priv->base + HW_UARTAPP_CTRL2);
writel(0x0, priv->base + HW_UARTAPP_CTRL2);
/* Calculate and set baudrate */
quot = (clk_get_rate(priv->clk) * 32) / new_baudrate;
reg = BF_UARTAPP_LINECTRL_BAUD_DIVFRAC(quot & 0x3F) |
BF_UARTAPP_LINECTRL_BAUD_DIVINT(quot >> 6) |
BF_UARTAPP_LINECTRL_WLEN(3) |
BM_UARTAPP_LINECTRL_FEN;
writel(reg, priv->base + HW_UARTAPP_LINECTRL);
/* Re-enable UART */
writel(ctrl2, priv->base + HW_UARTAPP_CTRL2);
priv->baudrate = new_baudrate;
return 0;
}
static int auart_clocksource_clock_change(struct notifier_block *nb, unsigned long event, void *data)
{
struct auart_priv *priv = container_of(nb, struct auart_priv, notify);
return auart_serial_setbaudrate(&priv->cdev, priv->baudrate);
}
static void auart_serial_init_port(struct auart_priv *priv)
{
stmp_reset_block(priv->base + HW_UARTAPP_CTRL0, 0);
/* Disable UART */
writel(0x0, priv->base + HW_UARTAPP_CTRL2);
/* Mask interrupts */
writel(0x0, priv->base + HW_UARTAPP_INTR);
}
static int auart_serial_probe(struct device_d *dev)
{
struct auart_priv *priv;
struct console_device *cdev;
priv = xzalloc(sizeof *priv);
cdev = &priv->cdev;
cdev->tstc = auart_serial_tstc;
cdev->putc = auart_serial_putc;
cdev->getc = auart_serial_getc;
cdev->flush = auart_serial_flush;
cdev->setbrg = auart_serial_setbaudrate;
cdev->dev = dev;
dev->priv = priv;
priv->base = dev_request_mem_region(dev, 0);
priv->clk = clk_get(dev, NULL);
if (IS_ERR(priv->clk))
return PTR_ERR(priv->clk);
auart_serial_init_port(priv);
/* Disable RTS/CTS, enable Rx, Tx, UART */
writel(BM_UARTAPP_CTRL2_RTSEN | BM_UARTAPP_CTRL2_CTSEN |
BM_UARTAPP_CTRL2_USE_LCR2,
priv->base + HW_UARTAPP_CTRL2_CLR);
writel(BM_UARTAPP_CTRL2_RXE | BM_UARTAPP_CTRL2_TXE |
BM_UARTAPP_CTRL2_UARTEN,
priv->base + HW_UARTAPP_CTRL2_SET);
console_register(cdev);
priv->notify.notifier_call = auart_clocksource_clock_change;
clock_register_client(&priv->notify);
return 0;
}
static void auart_serial_remove(struct device_d *dev)
{
struct auart_priv *priv = dev->priv;
auart_serial_flush(&priv->cdev);
console_unregister(&priv->cdev);
free(priv);
}
static struct driver_d auart_serial_driver = {
.name = "auart_serial",
.probe = auart_serial_probe,
.remove = auart_serial_remove,
};
console_platform_driver(auart_serial_driver);