On Mon, Mar 11, 2013 at 10:14:58AM +0100, Steffen Trumtrar wrote:
> Support for Cadence UART core.
>
> Signed-off-by: Steffen Trumtrar <[email protected]>
> ---
> drivers/serial/Kconfig | 4 +
> drivers/serial/Makefile | 1 +
> drivers/serial/serial_cadence.c | 299
> ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 304 insertions(+)
> create mode 100644 drivers/serial/serial_cadence.c
>
> diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
> index f61d670..a51510e 100644
> --- a/drivers/serial/Kconfig
> +++ b/drivers/serial/Kconfig
> @@ -113,4 +113,8 @@ config DRIVER_SERIAL_OMAP4_USBBOOT
> help
> Enable this to get console support over the usb bus used to boot an
> OMAP4
>
> +config DRIVER_SERIAL_CADENCE
> + default n
> + bool "Cadence UART driver"
> +
> endmenu
> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> index 893e282..963a7df 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_CADENCE) += serial_cadence.o
> diff --git a/drivers/serial/serial_cadence.c b/drivers/serial/serial_cadence.c
> new file mode 100644
> index 0000000..0ccb1b3
> --- /dev/null
> +++ b/drivers/serial/serial_cadence.c
> @@ -0,0 +1,299 @@
> +/*
> + * (c) 2012 Steffen Trumtrar <[email protected]>
> + *
> + * 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 <driver.h>
> +#include <init.h>
> +#include <malloc.h>
> +#include <notifier.h>
> +#include <io.h>
> +#include <linux/err.h>
> +#include <linux/clk.h>
> +
> +#define CADENCE_UART_CONTROL 0x00
> +#define CADENCE_UART_MODE 0x04
> +#define CADENCE_UART_BAUD_GEN 0x18
> +#define CADENCE_UART_CHANNEL_STS 0x2C
> +#define CADENCE_UART_RXTXFIFO 0x30
> +#define CADENCE_UART_BAUD_DIV 0x34
> +
> +#define CADENCE_CTRL_RXRES (1 << 0)
> +#define CADENCE_CTRL_TXRES (1 << 1)
> +#define CADENCE_CTRL_RXEN (1 << 2)
> +#define CADENCE_CTRL_RXDIS (1 << 3)
> +#define CADENCE_CTRL_TXEN (1 << 4)
> +#define CADENCE_CTRL_TXDIS (1 << 5)
> +#define CADENCE_CTRL_RSTTO (1 << 6)
> +#define CADENCE_CTRL_STTBRK (1 << 7)
> +#define CADENCE_CTRL_STPBRK (1 << 8)
> +
> +#define CADENCE_MODE_CLK_REF (0 << 0)
> +#define CADENCE_MODE_CLK_REF_DIV (1 << 0)
> +#define CADENCE_MODE_CHRL_6 (3 << 1)
> +#define CADENCE_MODE_CHRL_7 (2 << 1)
> +#define CADENCE_MODE_CHRL_8 (0 << 1)
> +#define CADENCE_MODE_PAR_EVEN (0 << 3)
> +#define CADENCE_MODE_PAR_ODD (1 << 3)
> +#define CADENCE_MODE_PAR_SPACE (2 << 3)
> +#define CADENCE_MODE_PAR_MARK (3 << 3)
> +#define CADENCE_MODE_PAR_NONE (4 << 3)
> +
> +#define CADENCE_STS_REMPTY (1 << 1)
> +#define CADENCE_STS_RFUL (1 << 2)
> +#define CADENCE_STS_TEMPTY (1 << 3)
> +#define CADENCE_STS_TFUL (1 << 4)
> +
> +/*
> + * create default values for different platforms
> + */
> +struct cadence_serial_devtype_data {
> + u32 ctrl;
> + u32 mode;
> +};
> +
> +static struct cadence_serial_devtype_data cadence7000_data = {
> + .ctrl = CADENCE_CTRL_RXEN | CADENCE_CTRL_TXEN,
> + .mode = CADENCE_MODE_CLK_REF | CADENCE_MODE_CHRL_8 |
> CADENCE_MODE_PAR_NONE,
> +};
> +
> +struct cadence_serial_priv {
> + struct console_device cdev;
> + int baudrate;
> + struct notifier_block notify;
> + void __iomem *regs;
> + /*struct clk *clk;*/
> + unsigned long clk;
> + struct cadence_serial_devtype_data *devtype;
> +};
> +
> +static int cadence_serial_reset(struct console_device *cdev)
> +{
> + struct cadence_serial_priv *priv = container_of(cdev,
> + struct cadence_serial_priv, cdev);
> +
> + /* Soft-Reset Tx/Rx paths */
> + writel(CADENCE_CTRL_RXRES | CADENCE_CTRL_TXRES, priv->regs +
> + CADENCE_UART_CONTROL);
> +
> + while (readl(priv->regs + CADENCE_UART_CONTROL) &
> + (CADENCE_CTRL_RXRES | CADENCE_CTRL_TXRES))
> + ;
> +
> + return 0;
> +}
> +
> +static int cadence_serial_setbaudrate(struct console_device *cdev, int
> baudrate)
> +{
> + struct cadence_serial_priv *priv = container_of(cdev,
> + struct cadence_serial_priv, cdev);
> + unsigned int gen, div;
> + int calc_rate;
> + unsigned long clk;
> + int error;
> + int val;
> +
> + clk = priv->clk;
> + priv->baudrate = baudrate;
> +
> + /* disable transmitter and receiver */
> + val = readl(priv->regs + CADENCE_UART_CONTROL);
> + val &= ~CADENCE_CTRL_TXEN & ~CADENCE_CTRL_RXEN;
> + writel(val, priv->regs + CADENCE_UART_CONTROL);
> +
> + /*
> + * clk
> + * rate = -----------
> + * gen*(div+1)
> + */
> +
> + for (div = 4; div < 256; div++) {
> + gen = clk / (baudrate * (div + 1));
> +
> + if (gen < 1 || gen > 65535)
> + continue;
> +
> + calc_rate = clk / (gen * (div + 1));
> + error = baudrate - calc_rate;
> + if (error < 0)
> + error *= -1;
> + if (((error * 100) / baudrate) < 3)
> + break;
> + }
> +
> + writel(gen, priv->regs + CADENCE_UART_BAUD_GEN);
> + writel(div, priv->regs + CADENCE_UART_BAUD_DIV);
> +
> + /* Soft-Reset Tx/Rx paths */
> + writel(CADENCE_CTRL_RXRES | CADENCE_CTRL_TXRES, priv->regs +
> + CADENCE_UART_CONTROL);
> +
> + while (readl(priv->regs + CADENCE_UART_CONTROL) &
> + (CADENCE_CTRL_RXRES | CADENCE_CTRL_TXRES))
> + ;
> +
> + /* Enable UART */
> + writel(priv->devtype->ctrl, priv->regs + CADENCE_UART_CONTROL);
> +
> + return 0;
> +}
> +
> +static int cadence_serial_init_port(struct console_device *cdev)
> +{
> + struct cadence_serial_priv *priv = container_of(cdev,
> + struct cadence_serial_priv, cdev);
> +
> + cadence_serial_reset(cdev);
> +
> + cadence_serial_setbaudrate(cdev, 115200);
This shouldn't be necessary.
> +
> + /* Enable UART */
> + writel(priv->devtype->ctrl, priv->regs + CADENCE_UART_CONTROL);
> + writel(priv->devtype->mode, priv->regs + CADENCE_UART_MODE);
> +
> + return 0;
> +}
> +
> +static void cadence_serial_putc(struct console_device *cdev, char c)
> +{
> + struct cadence_serial_priv *priv = container_of(cdev,
> + struct cadence_serial_priv, cdev);
> +
> + while ((readl(priv->regs + CADENCE_UART_CHANNEL_STS) &
> + CADENCE_STS_TFUL) != 0)
> + ;
> +
> + if (c == '\n') {
> + writel('\r', priv->regs + CADENCE_UART_RXTXFIFO);
> + while ((readl(priv->regs + CADENCE_UART_CHANNEL_STS) &
> + CADENCE_STS_TFUL) != 0)
> + ;
> + }
The caller already added a '\r', don't do it again.
> +
> + writel(c, priv->regs + CADENCE_UART_RXTXFIFO);
> +}
> +
> +static int cadence_serial_tstc(struct console_device *cdev)
> +{
> + struct cadence_serial_priv *priv = container_of(cdev,
> + struct cadence_serial_priv, cdev);
> +
> + return ((readl(priv->regs + CADENCE_UART_CHANNEL_STS) &
> + CADENCE_STS_REMPTY) == 0);
> +}
> +
> +static int cadence_serial_getc(struct console_device *cdev)
> +{
> + struct cadence_serial_priv *priv = container_of(cdev,
> + struct cadence_serial_priv, cdev);
> +
> + while (!cadence_serial_tstc(cdev))
> + ;
> +
> + return readl(priv->regs + CADENCE_UART_RXTXFIFO);
> +}
> +
> +static void cadence_serial_flush(struct console_device *cdev)
> +{
> + struct cadence_serial_priv *priv = container_of(cdev,
> + struct cadence_serial_priv, cdev);
> +
> + while ((readl(priv->regs + CADENCE_UART_CHANNEL_STS) &
> + CADENCE_STS_TEMPTY) != 0)
> + ;
> +}
> +
> +static int cadence_clocksource_clock_change(struct notifier_block *nb,
> + unsigned long event, void *data)
> +{
> + return 0;
> +}
If you don't support this operation then please do not register a
callback for it.
> +
> +static int cadence_serial_probe(struct device_d *dev)
> +{
> + struct console_device *cdev;
> + struct cadence_serial_priv *priv;
> + struct cadence_serial_devtype_data *devtype;
> + int ret;
> +
> + ret = dev_get_drvdata(dev, (unsigned long *)&devtype);
> + if (ret)
> + return ret;
> +
> + priv = xzalloc(sizeof(*priv));
> + priv->devtype = devtype;
> + cdev = &priv->cdev;
> + dev->priv = priv;
> +
> + priv->clk = 50000000;
This should be fixed of course.
> + if (devtype->mode & CADENCE_MODE_CLK_REF_DIV)
> + priv->clk /= 8;
> +
> + priv->regs = dev_request_mem_region(dev, 0);
Please bail out here. I know, currently noone does, but we really need
to fix this as all drivers which miss the check silently derefence NULL
pointers.
> + .probe = cadence_serial_probe,
> + .remove = cadence_serial_remove,
> + .of_compatible = DRV_OF_COMPAT(cadence_serial_dt_ids),
> + .id_table = cadence_serial_ids,
> +};
> +
> +static int cadence_serial_init(void)
> +{
> + platform_driver_register(&cadence_serial_driver);
> + return 0;
return platform_driver_register...
Sascha
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