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SubjectRe: [RFC][PATCH]: Adding support for omap-serail driver
Hi,

Some comments below.

* vimal singh <vimal.newwork@gmail.com> [090828 06:52]:
> From: Govindraj R <govindraj.raja@ti.com>
>
> This patch adds support for OMAP3430-HIGH SPEED UART Controller.
>
> It currently adds support for the following features.
>
> 1. Supports Interrupt Mode for all three UARTs on SDP/ZOOM2.
> 2. Supports DMA Mode for all three UARTs on SDP/ZOOM2.
> 3. Supports Hardware flow control (CTS/RTS) on SDP/ZOOM2.
> 4. Supports 3.6Mbps baudrate on SDP/ZOOM2.
> 5. Debug Console support on all UARTs on SDP/ZOOM2.
> 6. Support for quad uart on ZOOM2 board.
>
> The reason for adding this new driver alternative to 8250 is to avoid
> polluting 8250 driver with too many omap specific data as 8250 already
> supports more than 16 different uart controllers and may need too
> many omap-platform checks to implement feature like DMA support.

Just the DMA and PM features should be enough to justify having a
custom driver for sure.

> diff --git a/arch/arm/plat-omap/include/mach/omap-serial.h
> b/arch/arm/plat-omap/include/mach/omap-serial.h
> new file mode 100644
> index 0000000..d1b0bf2
> --- /dev/null
> +++ b/arch/arm/plat-omap/include/mach/omap-serial.h
> @@ -0,0 +1,84 @@
> +/*
> + * arch/arm/plat-omap/include/mach/omap-serial.h
> + *
> + * Driver for OMAP3430 UART controller.
> + *
> + * Copyright (C) 2009 Texas Instruments.
> + *
> + * Authors:
> + * Thara Gopinath <thara@ti.com>
> + * Govindraj R <govindraj.raja@ti.com>
> + *
> + * 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.
> + */
> +
> +#ifndef __OMAP_SERIAL_H__
> +#define __OMAP_SERIAL_H__
> +
> +#include <linux/serial_core.h>
> +#include <linux/platform_device.h>
> +
> +/* TI OMAP CONSOLE */
> +#define PORT_OMAP 86
> +
> +#define DRIVER_NAME "omap-hsuart"
> +
> +/*
> + * We default to IRQ0 for the "no irq" hack. Some
> + * machine types want others as well - they're free
> + * to redefine this in their header file.
> + */
> +#define is_real_interrupt(irq) ((irq) != 0)
> +
> +#if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
> +#define SUPPORT_SYSRQ
> +#endif
> +
> +#ifdef CONFIG_ARCH_OMAP34XX
> +#define OMAP_MDR1_DISABLE 0x07
> +#define OMAP_MDR1_MODE13X 0x03
> +#define OMAP_MDR1_MODE16X 0x00
> +#define OMAP_MODE13X_SPEED 230400
> +#endif

Omap34xx specific things should be set dynamically during init rather
than using ifdefs. Maybe do the low level init in mach-omap2/serial.c?
That way the driver stays clean of any processor specific hacks.


> +
> +#define CONSOLE_NAME "console="
> +
> +#define UART_CLK (48000000)
> +#define QUART_CLK (1843200)
> +
> +/* UART NUMBERS */
> +#define UART1 (0x0)
> +#define UART2 (0x1)
> +#define UART3 (0x2)
> +#define QUART (0x3)
> +
> +#ifdef CONFIG_MACH_OMAP_ZOOM2
> +#define MAX_UARTS QUART
> +#else
> +#define MAX_UARTS UART3
> +#endif

This should be passed via platform_data.


> +
> +#define UART_BASE(uart_no) (uart_no == UART1) ? OMAP_UART1_BASE :\
> + (uart_no == UART2) ? OMAP_UART2_BASE :\
> + OMAP_UART3_BASE
> +
> +#define UART_MODULE_BASE(uart_no) (UART1 == uart_no ? \
> + IO_ADDRESS(OMAP_UART1_BASE) :\
> + (UART2 == uart_no ? \
> + IO_ADDRESS(OMAP_UART2_BASE) :\
> + IO_ADDRESS(OMAP_UART3_BASE)))

These too you can easily set in mach-omap2/serial.c so similar.


> +extern unsigned int fcr[MAX_UARTS];
> +extern char *saved_command_line;
> +
> +struct plat_serialomap_port {
> + void __iomem *membase; /* ioremap cookie or NULL */
> + resource_size_t mapbase; /* resource base */

Extra space after tab. Please run through checkpatch.pl --strict.


> + unsigned int irq; /* interrupt number */
> + unsigned char regshift; /* register shift */
> + upf_t flags; /* UPF_* flags */
> + void *private_data;
> +};
> +
> +#endif /* __OMAP_SERIAL_H__ */
> diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
> index 037c1e0..906fb61 100644
> --- a/drivers/serial/Kconfig
> +++ b/drivers/serial/Kconfig
> @@ -1359,6 +1359,98 @@ config SERIAL_OF_PLATFORM
> Currently, only 8250 compatible ports are supported, but
> others can easily be added.
>
> +config SERIAL_OMAP
> + bool "OMAP serial port support"
> + depends on ARM && ARCH_OMAP
> + select SERIAL_CORE
> + help
> + If you have a machine based on an Texas Instruments OMAP CPU you
> + can enable its onboard serial ports by enabling this option.
> +
> +config SERIAL_OMAP_CONSOLE
> + bool "Console on OMAP serial port"
> + depends on SERIAL_OMAP
> + select SERIAL_CORE_CONSOLE
> + help
> + If you have enabled the serial port on the Texas Instruments OMAP
> + CPU you can make it the console by answering Y to this option.
> +
> + Even if you say Y here, the currently visible virtual console
> + (/dev/tty0) will still be used as the system console by default, but
> + you can alter that using a kernel command line option such as
> + "console=ttyS0". (Try "man bootparam" or see the documentation of
> + your boot loader (lilo or loadlin) about how to pass options to the
> + kernel at boot time.)
> +
> +config SERIAL_OMAP_DMA_UART1
> + bool "UART1 DMA support"
> + depends on SERIAL_OMAP
> + help
> + If you have enabled the serial port on the Texas Instruments OMAP
> + CPU you can enable the DMA transfer on UART 1 by answering
> + to this option.
> +

No need for Kconfig option. Please pass from board-*.c files in platform_data.


> +config SERIAL_OMAP_UART1_RXDMA_TIMEOUT
> + int "Timeout value for RX DMA in microseconds"
> + depends on SERIAL_OMAP_DMA_UART1
> + default "1"
> + help
> + Set the timeout value in which you want the data pulled by RX dma to
> + be passed to the tty framework.

Ditto.


> +
> +config SERIAL_OMAP_UART1_RXDMA_BUFSIZE
> + int "DMA buffer size for RX in bytes"
> + depends on SERIAL_OMAP_DMA_UART1
> + default "4096"
> + help
> + Set the dma buffer size for UART Rx

Ditto for all other ports too.

<snip>

> diff --git a/drivers/serial/omap-serial.c b/drivers/serial/omap-serial.c
> new file mode 100644
> index 0000000..3b84740
> --- /dev/null
> +++ b/drivers/serial/omap-serial.c
> @@ -0,0 +1,1431 @@
> +/*
> + * drivers/serial/omap-serial.c
> + *
> + * Driver for OMAP3430 UART controller.
> + *
> + * Copyright (C) 2009 Texas Instruments.
> + *
> + * Authors:
> + * Thara Gopinath <thara@ti.com>
> + * Govindraj R <govindraj.raja@ti.com>
> + *
> + * 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.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/console.h>
> +#include <linux/serial_reg.h>
> +#include <linux/delay.h>
> +#include <linux/tty.h>
> +#include <linux/tty_flip.h>
> +#include <linux/io.h>
> +#include <linux/dma-mapping.h>
> +
> +#include <asm/irq.h>
> +#include <mach/dma.h>
> +#include <mach/dmtimer.h>
> +#include <mach/omap-serial.h>
> +
> +#ifdef DEBUG
> +#define DPRINTK printk
> +#else
> +#define DPRINTK(x...)
> +#endif

Please get rid of custom debug functions.

<snip>

> + if (*status & UART_LSR_BI)
> + flag = TTY_BREAK;
> + else if (*status & UART_LSR_PE)
> + flag = TTY_PARITY;
> + else if (*status & UART_LSR_FE)
> + flag = TTY_FRAME;
> + }
> +
> + if (uart_handle_sysrq_char(&up->port, ch))
> + goto ignore_char;
> +
> + uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
> +
> +ignore_char:
> + *status = serial_in(up, UART_LSR);
> + } while ((*status & UART_LSR_DR) && (max_count-- > 0));
> + tty_flip_buffer_push(tty);
> +
> +
> +}

Extras lines at the end of function, you might want to remove.

<snip>

> +static struct console serial_omap_console = {
> + .name = "ttyS",
> + .write = serial_omap_console_write,
> + .device = uart_console_device,
> + .setup = serial_omap_console_setup,
> + .flags = CON_PRINTBUFFER,
> + .index = -1,
> + .data = &serial_omap_reg,
> +};

I believe you'll need to use some other name than ttyS. Otherwise
it will conflict with hotpluggable 8250 devices, such as bluetooth.


> +static struct uart_driver serial_omap_reg = {
> + .owner = THIS_MODULE,
> + .driver_name = "OMAP-SERIAL",
> + .dev_name = "ttyS",
> + .major = TTY_MAJOR,
> + .minor = 64,
> + .nr = 4,
> + .cons = OMAP_CONSOLE,
> +};

Here too. Maybe ttyO for the name?

Regards,

Tony


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