[PATCH 2/2] driver/serial: add driver for the mxs application uart
Sascha Hauer
s.hauer at pengutronix.de
Tue Feb 26 14:02:08 EST 2013
On Tue, Feb 26, 2013 at 07:34:50PM +0100, Marc Kleine-Budde wrote:
> Signed-off-by: Marc Kleine-Budde <mkl at pengutronix.de>
> ---
> drivers/serial/Makefile | 1 +
> drivers/serial/serial_auart.c | 257 +++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 258 insertions(+)
> create mode 100644 drivers/serial/serial_auart.c
>
> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> index 893e282..6b90593 100644
> --- a/drivers/serial/Makefile
> +++ b/drivers/serial/Makefile
> @@ -21,3 +21,4 @@ obj-$(CONFIG_DRIVER_SERIAL_ALTERA) += serial_altera.o
> obj-$(CONFIG_DRIVER_SERIAL_ALTERA_JTAG) += serial_altera_jtag.o
> obj-$(CONFIG_DRIVER_SERIAL_PXA) += serial_pxa.o
> obj-$(CONFIG_DRIVER_SERIAL_OMAP4_USBBOOT) += serial_omap4_usbboot.o
> +obj-$(CONFIG_DRIVER_SERIAL_AUART) += serial_auart.o
> diff --git a/drivers/serial/serial_auart.c b/drivers/serial/serial_auart.c
> new file mode 100644
> index 0000000..5208a5d
> --- /dev/null
> +++ b/drivers/serial/serial_auart.c
> @@ -0,0 +1,257 @@
> +/*
> + * (C) 2013 Marc Kleine-Budde <mkl at 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 at reccoware.de>
> + *
> + * Based on the standard DUART serial driver:
> + *
> + * (C) 2007 Sascha Hauer <s.hauer at 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 at 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 <mach/clock.h>
> +#include <mach/imx-regs.h>
> +
> +#define HW_UARTAPP_CTRL0 (0x00000000)
> +#define HW_UARTAPP_CTRL0_CLR (0x00000008)
> +#define BM_UARTAPP_CTRL0_SFTRST (0x80000000)
> +#define BM_UARTAPP_CTRL0_CLKGATE (0x40000000)
> +
> +#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;
> +};
> +
> +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 TX FIFO is empty */
The commment seems wrong.
> + 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 = (imx_get_xclk() * 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 debug UART */
debug 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_reset(struct auart_priv *priv)
> +{
> + int i;
> +
> + writel(BM_UARTAPP_CTRL0_SFTRST, priv->base + HW_UARTAPP_CTRL0_CLR);
> +
> + for (i = 0; i < 10000; i++) {
> + uint32_t reg;
> +
> + reg = readl(priv->base + HW_UARTAPP_CTRL0);
> + if (!(reg & BM_UARTAPP_CTRL0_SFTRST))
> + break;
> + }
> +
> + writel(BM_UARTAPP_CTRL0_CLKGATE, priv->base + HW_UARTAPP_CTRL0_CLR);
> +}
Can you use mxs_reset_block here?
> +
> +static void auart_serial_init_port(struct auart_priv *priv)
> +{
> + auart_reset(priv);
> +
> + /* 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->f_caps = CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR;
> + 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);
> +
> + auart_serial_init_port(priv);
> + auart_serial_setbaudrate(cdev, CONFIG_BAUDRATE);
> +
> + /* 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,
> +};
> +
> +static int auart_serial_init(void)
> +{
> + platform_driver_register(&auart_serial_driver);
> + return 0;
return platform_driver_register please.
Sascha
--
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