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authorSimon Rettberg2026-01-28 12:53:53 +0100
committerSimon Rettberg2026-01-28 12:53:53 +0100
commit8e82785c584dc13e20f9229decb95bd17bbe9cd1 (patch)
treea8b359e59196be5b2e3862bed189107f4bc9975f /src/drivers/uart/dwuart.c
parentMerge branch 'master' into openslx (diff)
parent[prefix] Make unlzma.S compatible with 386 class CPUs (diff)
downloadipxe-openslx.tar.gz
ipxe-openslx.tar.xz
ipxe-openslx.zip
Merge branch 'master' into openslxopenslx
Diffstat (limited to 'src/drivers/uart/dwuart.c')
-rw-r--r--src/drivers/uart/dwuart.c129
1 files changed, 129 insertions, 0 deletions
diff --git a/src/drivers/uart/dwuart.c b/src/drivers/uart/dwuart.c
new file mode 100644
index 000000000..ce08e8ebf
--- /dev/null
+++ b/src/drivers/uart/dwuart.c
@@ -0,0 +1,129 @@
+/*
+ * 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;
+ uint32_t clock;
+ 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;
+
+ /* Get clock rate */
+ if ( ( rc = fdt_u32 ( &sysfdt, offset, "clock-frequency",
+ &clock ) ) != 0 ) {
+ clock = NS16550_CLK_DEFAULT;
+ }
+ ns16550->clock = clock;
+
+ /* 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",
+ "ns16550a",
+};
+
+/** 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,
+};