Re: [PATCH] Au1x00 8250 uart support.

From: Russell King
Date: Tue Sep 20 2005 - 11:41:23 EST


On Mon, Sep 19, 2005 at 11:40:10PM +0300, Pantelis Antoniou wrote:
> diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
> --- a/drivers/serial/8250.c
> +++ b/drivers/serial/8250.c
> @@ -249,10 +249,42 @@ static const struct serial8250_config ua
> .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
> .flags = UART_CAP_FIFO | UART_CAP_UUE,
> },
> + [PORT_AU1X00] = {
> + .name = "Au1x00",
> + .fifo_size = 16,
> + .tx_loadsz = 16,
> + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
> + .flags = UART_CAP_FIFO | UART_CAP_NOMSR,
> + },
> +};
> +
> +#ifdef CONFIG_SERIAL_8250_AU1X00
> +static const u8 au_io_in_map[] = {
> + [UART_RX] = 0,
> + [UART_IER] = 2,
> + [UART_IIR] = 3,
> + [UART_LCR] = 5,
> + [UART_MCR] = 6,
> + [UART_LSR] = 7,
> + [UART_MSR] = 8,
> };
>
> +static const u8 au_io_out_map[] = {
> + [UART_TX] = 1,
> + [UART_IER] = 2,
> + [UART_FCR] = 4,
> + [UART_LCR] = 5,
> + [UART_MCR] = 6,
> +};
> +#endif
> +
> static _INLINE_ unsigned int serial_in(struct uart_8250_port *up, int offset)
> {
> +#ifdef CONFIG_SERIAL_8250_AU1X00
> + if (up->port.iotype == UPIO_AU)
> + offset = au_io_in_map[offset];
> +#endif
> +
> offset <<= up->port.regshift;
>
> switch (up->port.iotype) {
> @@ -266,6 +298,11 @@ static _INLINE_ unsigned int serial_in(s
> case UPIO_MEM32:
> return readl(up->port.membase + offset);
>
> +#ifdef CONFIG_SERIAL_8250_AU1X00
> + case UPIO_AU:
> + return __raw_readl(up->port.membase + offset);
> +#endif
> +

At some point, we probably want to make this non-AU1x00 specific, but
it may as well wait until someone else has such quirkyness themselves.
It would be nice to pass the maps in somehow, but that's a fair re-jig
of the interfaces to other chunks of code elsewhere in the kernel tree.
Therefore, I think it's a change we should not make until there's a
reason to make it.

> default:
> return inb(up->port.iobase + offset);
> }
> @@ -274,6 +311,11 @@ static _INLINE_ unsigned int serial_in(s
> static _INLINE_ void
> serial_out(struct uart_8250_port *up, int offset, int value)
> {
> +#ifdef CONFIG_SERIAL_8250_AU1X00
> + if (up->port.iotype == UPIO_AU)
> + offset = au_io_out_map[offset];
> +#endif
> +
> offset <<= up->port.regshift;
>
> switch (up->port.iotype) {
> @@ -290,6 +332,12 @@ serial_out(struct uart_8250_port *up, in
> writel(value, up->port.membase + offset);
> break;
>
> +#ifdef CONFIG_SERIAL_8250_AU1X00
> + case UPIO_AU:
> + __raw_writel(value, up->port.membase + offset);
> + break;
> +#endif
> +
> default:
> outb(value, up->port.iobase + offset);
> }
> @@ -910,6 +958,15 @@ static void autoconfig(struct uart_8250_
> }
> }
> #endif
> +
> +#ifdef CONFIG_SERIAL_8250_AU1X00
> + /* if access method is AU, it is a AU */
> + if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU) {
> + up->port.type = PORT_AU1X00;

I don't really see the need for a new port type - it's a quirky
16550A with a silly register layout.

> + up->capabilities |= UART_CAP_NOMSR; /* to stop whine */

Since this is for a hardware quirk, this should be UART_BUG_xxx not
UART_CAP_xxx - it's not a capability as such.

> + }
> +#endif
> +
> serial_outp(up, UART_LCR, save_lcr);
>
> if (up->capabilities != uart_config[up->port.type].flags) {
> @@ -1057,6 +1114,10 @@ static void serial8250_enable_ms(struct
> {
> struct uart_8250_port *up = (struct uart_8250_port *)port;
>
> + /* no MSR capabilities */
> + if (up->capabilities & UART_CAP_NOMSR)

ditto.

> + return;
> +
> up->ier |= UART_IER_MSI;
> serial_out(up, UART_IER, up->ier);
> }
> @@ -1774,7 +1835,7 @@ serial8250_set_termios(struct uart_port
> * CTS flow control flag and modem status interrupts
> */
> up->ier &= ~UART_IER_MSI;
> - if (UART_ENABLE_MS(&up->port, termios->c_cflag))
> + if (!(up->capabilities & UART_CAP_NOMSR) && UART_ENABLE_MS(&up->port, termios->c_cflag))

ditto.

> up->ier |= UART_IER_MSI;
> if (up->capabilities & UART_CAP_UUE)
> up->ier |= UART_IER_UUE | UART_IER_RTOIE;
> diff --git a/drivers/serial/8250.h b/drivers/serial/8250.h
> --- a/drivers/serial/8250.h
> +++ b/drivers/serial/8250.h
> @@ -46,6 +46,7 @@ struct serial8250_config {
> #define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */
> #define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */
> #define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */
> +#define UART_CAP_NOMSR (1 << 13) /* UART has no modem status bits (Au1x00) */

ditto.

>
> #define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */
> #define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
> diff --git a/drivers/serial/8250_au1x00.c b/drivers/serial/8250_au1x00.c
> new file mode 100644
> --- /dev/null
> +++ b/drivers/serial/8250_au1x00.c
> @@ -0,0 +1,95 @@
> +/*
> + * Serial Device Initialisation for Au1x00
> + *
> + * (C) Copyright Embedded Alley Solutions, Inc 2005
> + * Author: Pantelis Antoniou <pantelis@xxxxxxxxxxxxxxxxx>
> + *
> + * 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.
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/ioport.h>
> +#include <linux/module.h>
> +#include <linux/serial_core.h>
> +#include <linux/signal.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +
> +#include <linux/serial_8250.h>
> +
> +#include <asm/mach-au1x00/au1000.h>
> +
> +#include "8250.h"
> +
> +#define PORT(_base, _irq) \
> + { \
> + .iobase = _base, \
> + .membase = (void __iomem *)_base,\
> + .mapbase = _base, \
> + .irq = _irq, \
> + .uartclk = 0, /* filled */ \
> + .regshift = 2, \
> + .iotype = UPIO_AU, \
> + .flags = UPF_SKIP_TEST | \
> + UPF_IOREMAP, \
> + }
> +
> +static struct plat_serial8250_port au1x00_data[] = {
> +#if defined(CONFIG_SOC_AU1000)
> + PORT(UART0_ADDR, AU1000_UART0_INT),
> + PORT(UART1_ADDR, AU1000_UART1_INT),
> + PORT(UART2_ADDR, AU1000_UART2_INT),
> + PORT(UART3_ADDR, AU1000_UART3_INT),
> +#elif defined(CONFIG_SOC_AU1500)
> + PORT(UART0_ADDR, AU1500_UART0_INT),
> + PORT(UART3_ADDR, AU1500_UART3_INT),
> +#elif defined(CONFIG_SOC_AU1100)
> + PORT(UART0_ADDR, AU1100_UART0_INT),
> + PORT(UART1_ADDR, AU1100_UART1_INT),
> + PORT(UART2_ADDR, AU1100_UART2_INT),
> + PORT(UART3_ADDR, AU1100_UART3_INT),
> +#elif defined(CONFIG_SOC_AU1550)
> + PORT(UART0_ADDR, AU1550_UART0_INT),
> + PORT(UART1_ADDR, AU1550_UART1_INT),
> + PORT(UART2_ADDR, AU1550_UART2_INT),
> + PORT(UART3_ADDR, AU1550_UART3_INT),
> +#elif defined(CONFIG_SOC_AU1200)
> + PORT(UART0_ADDR, AU1200_UART0_INT),
> + PORT(UART1_ADDR, AU1200_UART1_INT),
> +#endif
> + { },
> +};
> +
> +static struct platform_device au1x00_device = {
> + .name = "serial8250",
> + .id = PLAT8250_DEV_AU1X00,
> + .dev = {
> + .platform_data = au1x00_data,
> + },
> +};
> +
> +static int __init au1x00_init(void)
> +{
> + int i;
> + unsigned int uartclk;
> +
> + /* get uart clock */
> + uartclk = get_au1x00_uart_baud_base() * 16;
> +
> + /* fill up uartclk */
> + for (i = 0; au1x00_data[i].flags ; i++)
> + au1x00_data[i].uartclk = uartclk;
> +
> + return platform_device_register(&au1x00_device);

This seems to be capable of being a modular, yet it's registering a
static platform device structure, which will cause an oops if this
module is force-unloaded. Should it always be built in?

> +}
> +
> +module_init(au1x00_init);
> +
> +MODULE_AUTHOR("Pantelis Antoniou <pantelis@xxxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("8250 serial probe module for Au1x000 cards");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
> --- a/drivers/serial/Kconfig
> +++ b/drivers/serial/Kconfig
> @@ -207,6 +207,14 @@ config SERIAL_8250_ACORN
> system, say Y to this option. The driver can handle 1, 2, or 3 port
> cards. If unsure, say N.
>
> +config SERIAL_8250_AU1X00
> + tristate "AU1X00 serial port support"
> + depends on SOC_AU1X00 && SERIAL_8250
> + help
> + If you have an Au1x00 board and want to use the serial port, say Y
> + to this option. The driver can handle 1 or 2 serial ports.
> + If unsure, say N.
> +
> comment "Non-8250 serial port support"
>
> config SERIAL_AMBA_PL010
> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> --- a/drivers/serial/Makefile
> +++ b/drivers/serial/Makefile
> @@ -22,6 +22,7 @@ obj-$(CONFIG_SERIAL_8250_ACCENT) += 8250
> obj-$(CONFIG_SERIAL_8250_BOCA) += 8250_boca.o
> obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o
> obj-$(CONFIG_SERIAL_8250_MCA) += 8250_mca.o
> +obj-$(CONFIG_SERIAL_8250_AU1X00) += 8250_au1x00.o
> obj-$(CONFIG_SERIAL_AMBA_PL010) += amba-pl010.o
> obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o
> obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o
> diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
> --- a/drivers/serial/serial_core.c
> +++ b/drivers/serial/serial_core.c
> @@ -1960,6 +1960,7 @@ uart_report_port(struct uart_driver *drv
> break;
> case UPIO_MEM:
> case UPIO_MEM32:
> + case UPIO_AU:
> snprintf(address, sizeof(address),
> "MMIO 0x%lx", port->mapbase);
> break;
> diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
> --- a/include/linux/serial_8250.h
> +++ b/include/linux/serial_8250.h
> @@ -42,6 +42,7 @@ enum {
> PLAT8250_DEV_BOCA,
> PLAT8250_DEV_HUB6,
> PLAT8250_DEV_MCA,
> + PLAT8250_DEV_AU1X00,
> };
>
> /*
> diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
> --- a/include/linux/serial_core.h
> +++ b/include/linux/serial_core.h
> @@ -39,7 +39,8 @@
> #define PORT_RSA 13
> #define PORT_NS16550A 14
> #define PORT_XSCALE 15
> -#define PORT_MAX_8250 15 /* max port ID */
> +#define PORT_AU1X00 16
> +#define PORT_MAX_8250 16 /* max port ID */
>
> /*
> * ARM specific type numbers. These are not currently guaranteed
> @@ -209,6 +210,7 @@ struct uart_port {
> #define UPIO_HUB6 (1)
> #define UPIO_MEM (2)
> #define UPIO_MEM32 (3)
> +#define UPIO_AU (4) /* Au1x00 type IO */
>
> unsigned int read_status_mask; /* driver specific */
> unsigned int ignore_status_mask; /* driver specific */


--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
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