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

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/drivers/uart/dwuart.c b/src/drivers/uart/dwuart.c
new file mode 100644 (file)
index 0000000..bf83afd
--- /dev/null
+++ b/src/drivers/uart/dwuart.c
@@ -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,
+};

diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
index 1a39af43f8c09df1520f56d7d05f6d10dbd1b3c4..9eaa784fc5ed914e3bd0360ef0f477489e05bb7d 100644 (file)
--- a/src/include/ipxe/errfile.h
+++ b/src/include/ipxe/errfile.h
@@ -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 )