serial_bcm283x_pl011.c
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/*
* Copyright (c) 2018 Alexander Graf <agraf@suse.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <asm/gpio.h>
#include <dm/pinctrl.h>
#include <dm/platform_data/serial_pl01x.h>
#include <serial.h>
#include "serial_pl01x_internal.h"
/*
* Check if this serial device is muxed
*
* The serial device will only work properly if it has been muxed to the serial
* pins by firmware. Check whether that happened here.
*
* @return true if serial device is muxed, false if not
*/
static bool bcm283x_is_serial_muxed(void)
{
int serial_gpio = 15;
struct udevice *dev;
if (uclass_first_device(UCLASS_PINCTRL, &dev) || !dev)
return false;
if (pinctrl_get_gpio_mux(dev, 0, serial_gpio) != BCM2835_GPIO_ALT0)
return false;
return true;
}
static int bcm283x_pl011_serial_ofdata_to_platdata(struct udevice *dev)
{
struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
int ret;
/* Don't spawn the device if it's not muxed */
if (!bcm283x_is_serial_muxed())
return -ENODEV;
ret = pl01x_serial_ofdata_to_platdata(dev);
if (ret)
return ret;
/*
* TODO: Reinitialization doesn't always work for now, just skip
* init always - we know we're already initialized
*/
plat->skip_init = true;
return 0;
}
static int bcm283x_pl011_serial_setbrg(struct udevice *dev, int baudrate)
{
int r;
r = pl01x_serial_setbrg(dev, baudrate);
/*
* We may have been muxed to a bogus line before. Drain the RX
* queue so we start at a clean slate.
*/
while (pl01x_serial_getc(dev) != -EAGAIN) ;
return r;
}
static const struct dm_serial_ops bcm283x_pl011_serial_ops = {
.putc = pl01x_serial_putc,
.pending = pl01x_serial_pending,
.getc = pl01x_serial_getc,
.setbrg = bcm283x_pl011_serial_setbrg,
};
static const struct udevice_id bcm283x_pl011_serial_id[] = {
{.compatible = "brcm,bcm2835-pl011", .data = TYPE_PL011},
{}
};
U_BOOT_DRIVER(bcm283x_pl011_uart) = {
.name = "bcm283x_pl011",
.id = UCLASS_SERIAL,
.of_match = of_match_ptr(bcm283x_pl011_serial_id),
.ofdata_to_platdata = of_match_ptr(bcm283x_pl011_serial_ofdata_to_platdata),
.platdata_auto_alloc_size = sizeof(struct pl01x_serial_platdata),
.probe = pl01x_serial_probe,
.ops = &bcm283x_pl011_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
.priv_auto_alloc_size = sizeof(struct pl01x_priv),
};