[dwuart] Add a basic driver for the Synopsys DesignWare UART

Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown
2025-06-21 23:13:58 +01:00
parent cca1cfd49e
commit 53a3befb69
2 changed files with 121 additions and 0 deletions

120
src/drivers/uart/dwuart.c Normal file
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@@ -0,0 +1,120 @@
/*
* Copyright (C) 2025 Michael Brown <mbrown@fensystems.co.uk>.
*
* 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 any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
/** @file
*
* DesignWare UART
*
*/
#include <errno.h>
#include <ipxe/uart.h>
#include <ipxe/ns16550.h>
#include <ipxe/devtree.h>
#include <ipxe/fdt.h>
/**
* Probe devicetree device
*
* @v dt Devicetree device
* @v offset Starting node offset
* @ret rc Return status code
*/
static int dwuart_probe ( struct dt_device *dt, unsigned int offset ) {
struct ns16550_uart *ns16550;
struct uart *uart;
uint32_t shift;
int rc;
/* Allocate and initialise UART */
uart = alloc_uart ( sizeof ( *ns16550 ) );
if ( ! uart ) {
rc = -ENOMEM;
goto err_alloc;
}
uart->name = dt->name;
uart->op = &ns16550_operations;
ns16550 = uart->priv;
dt_set_drvdata ( dt, uart );
/* Map registers */
ns16550->base = dt_ioremap ( dt, offset, 0, 0 );
if ( ! ns16550->base ) {
rc = -ENODEV;
goto err_ioremap;
}
/* Get register shift */
if ( ( rc = fdt_u32 ( &sysfdt, offset, "reg-shift", &shift ) ) != 0 )
shift = 0;
ns16550->shift = shift;
/* Register UART */
if ( ( rc = uart_register ( uart ) ) != 0 )
goto err_register;
return 0;
uart_unregister ( uart );
err_register:
iounmap ( ns16550->base );
err_ioremap:
uart_nullify ( uart );
uart_put ( uart );
err_alloc:
return rc;
}
/**
* Remove devicetree device
*
* @v dt Devicetree device
*/
static void dwuart_remove ( struct dt_device *dt ) {
struct uart *uart = dt_get_drvdata ( dt );
struct ns16550_uart *ns16550 = uart->priv;
/* Unregister UART */
uart_unregister ( uart );
/* Free UART */
iounmap ( ns16550->base );
uart_nullify ( uart );
uart_put ( uart );
}
/** DesignWare UART compatible model identifiers */
static const char * dwuart_ids[] = {
"snps,dw-apb-uart",
};
/** DesignWare UART devicetree driver */
struct dt_driver dwuart_driver __dt_driver = {
.name = "dwuart",
.ids = dwuart_ids,
.id_count = ( sizeof ( dwuart_ids ) / sizeof ( dwuart_ids[0] ) ),
.probe = dwuart_probe,
.remove = dwuart_remove,
};

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@@ -110,6 +110,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#define ERRFILE_nvsvpd ( ERRFILE_DRIVER | 0x00140000 )
#define ERRFILE_uart ( ERRFILE_DRIVER | 0x00150000 )
#define ERRFILE_ns16550 ( ERRFILE_DRIVER | 0x00160000 )
#define ERRFILE_dwuart ( ERRFILE_DRIVER | 0x00170000 )
#define ERRFILE_3c509 ( ERRFILE_DRIVER | 0x00200000 )
#define ERRFILE_bnx2 ( ERRFILE_DRIVER | 0x00210000 )