[PATCH 3/5] ARM: zynq: add driver for Zynq uarts
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Sun Mar 3 05:37:58 EST 2013
On 18:48 Sat 02 Mar , Josh Cartwright wrote:
>
> Simple UART driver for Zynq SoCs, based loosely on the u-boot driver.
>
> Signed-off-by: Josh Cartwright <joshc at eso.teric.us>
> ---
> drivers/serial/Kconfig | 6 ++
> drivers/serial/Makefile | 1 +
> drivers/serial/serial_zynq.c | 144 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 151 insertions(+)
> create mode 100644 drivers/serial/serial_zynq.c
>
> diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
> index f61d670..608b616 100644
> --- a/drivers/serial/Kconfig
> +++ b/drivers/serial/Kconfig
> @@ -113,4 +113,10 @@ config DRIVER_SERIAL_OMAP4_USBBOOT
> help
> Enable this to get console support over the usb bus used to boot an OMAP4
>
> +config DRIVER_SERIAL_ZYNQ
> + bool "driver for Zynq uarts"
> + default n
> + help
> + Say Y here to get console out support with the Zynq uarts
> +
> endmenu
> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> index 893e282..883394f 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_ZYNQ) += serial_zynq.o
> diff --git a/drivers/serial/serial_zynq.c b/drivers/serial/serial_zynq.c
> new file mode 100644
> index 0000000..ec93b58
> --- /dev/null
> +++ b/drivers/serial/serial_zynq.c
> @@ -0,0 +1,144 @@
> +/*
> + * (C) Copyright 2013 Josh Cartwright
> + *
> + * Based very loosely on u-boot drivers/serial/serial_zynq.c.
> + *
> + * Copyright (C) 2012 Michal Simek <monstr at monstr.eu>
> + * Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved.
> + *
> + * 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 <io.h>
> +#include <init.h>
> +#include <driver.h>
> +#include <xfuncs.h>
> +#include <console.h>
> +#include <malloc.h>
> +
> +#include <linux/clk.h>
> +
> +#define UART_CR 0x00000000
> +#define UART_CR_TXEN (1<<4)
> +#define UART_CR_RXEN (1<<2)
> +#define UART_CR_TXRST (1<<1)
> +#define UART_CR_RXRST (1<<0)
> +
> +#define UART_SR 0x0000002C
> +#define UART_SR_TXFULL (1<<4)
> +#define UART_SR_TXEMPTY (1<<3)
> +#define UART_SR_RXFULL (1<<2)
> +#define UART_SR_RXEMPTY (1<<1)
> +
> +#define UART_FIFO 0x00000030
> +
> +struct zynq_serial_device {
> + struct console_device cdev;
> + struct clk *clk;
> + void __iomem *regs;
> +};
> +
> +#define to_zynq_device(p) container_of(p, struct zynq_serial_device, cdev)
> +
> +static void zynq_serial_init_device(struct zynq_serial_device *dev)
> +{
> + writel(UART_CR_TXEN | UART_CR_RXEN | UART_CR_TXEN | UART_CR_RXEN,
> + dev->regs + UART_CR);
> +}
> +
> +static int zynq_serial_tstc(struct console_device *cdev)
> +{
> + struct zynq_serial_device *zynq = to_zynq_device(cdev);
> +
> + return !(readl(zynq->regs + UART_SR) & UART_SR_RXEMPTY);
> +}
> +
> +static void zynq_serial_putc(struct console_device *cdev, char c)
> +{
> + struct zynq_serial_device *zynq = to_zynq_device(cdev);
> +
> + while (readl(zynq->regs + UART_SR) & UART_SR_TXFULL);
> +
> + writel(c, zynq->regs + UART_FIFO);
> +}
> +
> +static int zynq_serial_getc(struct console_device *cdev)
> +{
> + struct zynq_serial_device *zynq = to_zynq_device(cdev);
> +
> + return readl(zynq->regs + UART_FIFO);
> +}
> +
> +static void zynq_serial_flush(struct console_device *cdev)
> +{
> + struct zynq_serial_device *zynq = to_zynq_device(cdev);
> +
> + while (!(readl(zynq->regs + UART_SR) & UART_SR_TXEMPTY));
> +}
> +
> +static int zynq_serial_probe(struct device_d *dev)
> +{
> + struct zynq_serial_device *priv;
> + struct console_device *cdev;
> + int err;
> +
> + priv = xzalloc(sizeof(*priv));
> + cdev = &priv->cdev;
> +
> + priv->regs = dev_request_mem_region(dev, 0);
> + cdev->dev = dev;
> + cdev->f_caps = CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR;
> + cdev->tstc = zynq_serial_tstc;
> + cdev->putc = zynq_serial_putc;
> + cdev->getc = zynq_serial_getc;
> + cdev->flush = zynq_serial_flush;
> +
> + priv->clk = clk_get(dev, NULL);
> +
> + err = clk_enable(priv->clk);
> + if (err) {
> + free(priv);
> + return err;
> + }
> +
> + zynq_serial_init_device(priv);
> +
> + dev->priv = priv;
> +
> + return console_register(cdev);
> +}
> +
> +static void zynq_serial_remove(struct device_d *dev)
> +{
> + struct zynq_serial_device *zynq = dev->priv;
> + clk_disable(zynq->clk);
> + free(zynq);
do;nt do so otherwise the kernel will have no uart for decompress and
earlyprintk
> +}
> +
> +static struct driver_d zynq_serial_driver = {
> + .name = "zynq_serial",
> + .probe = zynq_serial_probe,
> + .remove = zynq_serial_remove,
> +};
> +
> +static int zynq_serial_init(void)
> +{
> + return platform_driver_register(&zynq_serial_driver);
> +}
> +console_initcall(zynq_serial_init);
> --
> 1.8.1.2
>
>
>
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