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path: root/drivers/serial/serial_bcm283x_pl011.c
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Diffstat (limited to 'drivers/serial/serial_bcm283x_pl011.c')
-rw-r--r--drivers/serial/serial_bcm283x_pl011.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/drivers/serial/serial_bcm283x_pl011.c b/drivers/serial/serial_bcm283x_pl011.c
new file mode 100644
index 0000000000..bfd39f84f3
--- /dev/null
+++ b/drivers/serial/serial_bcm283x_pl011.c
@@ -0,0 +1,73 @@
+/*
+ * 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_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 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 = &pl01x_serial_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+ .priv_auto_alloc_size = sizeof(struct pl01x_priv),
+};