On Tue, 16 Oct 2012 23:39:56 +0200
Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote:
...
> > > We already had this. This SoC has a very strange register layout. The
> > > registers for the UARTs are spread around the SoC and the registers
> > > are not even exclusively used for the UARTs. They have bits which are
> > > also used for the timer and other stuff.
> > use the device id to select the register is wrong
> >
> > we need to pass the register via resource (without request) or platform data
> > >
> > > > > +static int clps711x_tstc(struct console_device *cdev)
> > > > > +{
> > > > > + return !(readl(SYSFLG(cdev->dev->id)) & SYSFLG_URXFE);
> > > > factorise those pull status as
> > > >
> > > > status int xxx(data, mask) {}
> > >
> > > I don'r understand this. This is a single register read, there's not
> > > much to factorize and the code is easy to read.
> > he use the code at a least 2 place
>
> Testing for a bit like above is done a thousand times all around the
> kernel and barebox. There is nothing to factorize. The way Alexander did
> it is perfectly fine.
Please look on new version below. If it looks OK, I will make complete v2 patch.
Thanks!
/*
* Simple CLPS711X serial driver
*
* (C) Copyright 2012 Alexander Shiyan <shc_work@xxxxxxx>
*
* 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 <common.h>
#include <malloc.h>
#include <init.h>
#include <io.h>
#include <linux/clk.h>
#include <mach/clps711x.h>
struct clps711x_uart {
void __iomem *UBRLCR;
void __iomem *SYSCON;
void __iomem *SYSFLG;
void __iomem *UARTDR;
struct clk *uart_clk;
struct console_device cdev;
};
static int clps711x_setbaudrate(struct console_device *cdev, int baudrate)
{
struct clps711x_uart *s = cdev->dev->priv;
int divisor;
u32 tmp;
divisor = (clk_get_rate(s->uart_clk) / 16) / baudrate;
tmp = readl(s->UBRLCR) & ~UBRLCR_BAUD_MASK;
tmp |= divisor - 1;
writel(tmp, s->UBRLCR);
return 0;
}
static void clps711x_init_port(struct console_device *cdev)
{
struct clps711x_uart *s = cdev->dev->priv;
u32 tmp;
/* Disable the UART */
writel(readl(s->SYSCON) & ~SYSCON_UARTEN, s->SYSCON);
/* Setup Line Control Register */
tmp = readl(s->UBRLCR) & UBRLCR_BAUD_MASK;
tmp |= UBRLCR_FIFOEN | UBRLCR_WRDLEN8; /* FIFO on, 8N1 mode */
writel(tmp, s->UBRLCR);
/* Set default baudrate on initialization */
clps711x_setbaudrate(cdev, CONFIG_BAUDRATE);
/* Enable the UART */
writel(readl(s->SYSCON) | SYSCON_UARTEN, s->SYSCON);
}
static void clps711x_putc(struct console_device *cdev, char c)
{
struct clps711x_uart *s = cdev->dev->priv;
/* Wait until there is space in the FIFO */
while (readl(s->SYSFLG) & SYSFLG_UTXFF)
barrier();
/* Send the character */
writew(c, s->UARTDR);
}
static int clps711x_getc(struct console_device *cdev)
{
struct clps711x_uart *s = cdev->dev->priv;
u16 data;
/* Wait until there is data in the FIFO */
while (readl(s->SYSFLG) & SYSFLG_URXFE)
barrier();
data = readw(s->UARTDR);
/* Check for an error flag */
if (data & (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR))
return -1;
return (int)data;
}
static int clps711x_tstc(struct console_device *cdev)
{
struct clps711x_uart *s = cdev->dev->priv;
return !(readl(s->SYSFLG) & SYSFLG_URXFE);
}
static void clps711x_flush(struct console_device *cdev)
{
struct clps711x_uart *s = cdev->dev->priv;
while (readl(s->SYSFLG) & SYSFLG_UBUSY)
barrier();
}
static int clps711x_probe(struct device_d *dev)
{
struct clps711x_uart *s;
BUG_ON(dev->num_resources != 4);
s = xzalloc(sizeof(struct clps711x_uart));
s->uart_clk = clk_get(dev, NULL);
BUG_ON(!s->uart_clk);
s->UBRLCR = dev_get_mem_region(dev, 0);
s->SYSCON = dev_get_mem_region(dev, 1);
s->SYSFLG = dev_get_mem_region(dev, 2);
s->UARTDR = dev_get_mem_region(dev, 3);
dev->priv = s;
s->cdev.dev = dev;
s->cdev.f_caps = CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR;
s->cdev.tstc = clps711x_tstc;
s->cdev.putc = clps711x_putc;
s->cdev.getc = clps711x_getc;
s->cdev.flush = clps711x_flush;
s->cdev.setbrg = clps711x_setbaudrate;
clps711x_init_port(&s->cdev);
return console_register(&s->cdev);
}
static void clps711x_remove(struct device_d *dev)
{
struct clps711x_uart *s = dev->priv;
clps711x_flush(&s->cdev);
console_unregister(&s->cdev);
free(s);
}
static struct driver_d clps711x_driver = {
.name = "clps711x_serial",
.probe = clps711x_probe,
.remove = clps711x_remove,
};
static int clps711x_init(void)
{
return platform_driver_register(&clps711x_driver);
}
console_initcall(clps711x_init);
--
Alexander Shiyan <shc_work@xxxxxxx>
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