102 lines
2.4 KiB
C
102 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (c) 2018 Alexander Graf <agraf@suse.de>
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*/
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#include <common.h>
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#include <dm.h>
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#include <asm/gpio.h>
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#include <dm/pinctrl.h>
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#include <dm/platform_data/serial_pl01x.h>
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#include <serial.h>
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#include "serial_pl01x_internal.h"
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/*
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* Check if this serial device is muxed
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*
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* The serial device will only work properly if it has been muxed to the serial
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* pins by firmware. Check whether that happened here.
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*
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* @return true if serial device is muxed, false if not
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*/
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static bool bcm283x_is_serial_muxed(void)
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{
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int serial_gpio = 15;
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struct udevice *dev;
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if (uclass_first_device(UCLASS_PINCTRL, &dev) || !dev)
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return false;
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if (pinctrl_get_gpio_mux(dev, 0, serial_gpio) != BCM2835_GPIO_ALT0)
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return false;
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return true;
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}
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static int bcm283x_pl011_serial_probe(struct udevice *dev)
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{
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struct pl01x_serial_plat *plat = dev_get_plat(dev);
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int ret;
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/* Don't spawn the device if it's not muxed */
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if (!bcm283x_is_serial_muxed())
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return -ENODEV;
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/*
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* Read the ofdata here rather than in an of_to_plat() method
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* since we need the soc simple-bus to be probed so that the 'ranges'
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* property is used.
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*/
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ret = pl01x_serial_of_to_plat(dev);
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if (ret)
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return ret;
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/*
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* TODO: Reinitialization doesn't always work for now, just skip
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* init always - we know we're already initialized
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*/
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plat->skip_init = true;
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return pl01x_serial_probe(dev);
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}
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static int bcm283x_pl011_serial_setbrg(struct udevice *dev, int baudrate)
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{
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int r;
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r = pl01x_serial_setbrg(dev, baudrate);
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/*
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* We may have been muxed to a bogus line before. Drain the RX
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* queue so we start at a clean slate.
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*/
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while (pl01x_serial_getc(dev) != -EAGAIN) ;
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return r;
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}
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static const struct dm_serial_ops bcm283x_pl011_serial_ops = {
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.putc = pl01x_serial_putc,
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.pending = pl01x_serial_pending,
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.getc = pl01x_serial_getc,
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.setbrg = bcm283x_pl011_serial_setbrg,
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};
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static const struct udevice_id bcm283x_pl011_serial_id[] = {
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{.compatible = "brcm,bcm2835-pl011", .data = TYPE_PL011},
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{}
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};
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U_BOOT_DRIVER(bcm283x_pl011_uart) = {
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.name = "bcm283x_pl011",
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.id = UCLASS_SERIAL,
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.of_match = of_match_ptr(bcm283x_pl011_serial_id),
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.probe = bcm283x_pl011_serial_probe,
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.plat_auto = sizeof(struct pl01x_serial_plat),
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.ops = &bcm283x_pl011_serial_ops,
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#if !CONFIG_IS_ENABLED(OF_CONTROL) || CONFIG_IS_ENABLED(OF_BOARD)
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.flags = DM_FLAG_PRE_RELOC,
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#endif
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.priv_auto = sizeof(struct pl01x_priv),
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};
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