Signed-off-by: Antony Pavlov <antonynpavlov@xxxxxxxxx>
---
drivers/serial/Makefile | 1 +
drivers/serial/serial_litex.c | 96 +++++++++++++++++++++++++++++++++++
2 files changed, 97 insertions(+)
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 5120b17376..45055371ea 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -24,3 +24,4 @@ obj-$(CONFIG_DRIVER_SERIAL_DIGIC) += serial_digic.o
obj-$(CONFIG_DRIVER_SERIAL_LPUART) += serial_lpuart.o
obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o
obj-$(CONFIG_SERIAL_SIFIVE) += serial_sifive.o
+obj-$(CONFIG_SOC_LITEX) += serial_litex.o
diff --git a/drivers/serial/serial_litex.c b/drivers/serial/serial_litex.c
new file mode 100644
index 0000000000..8562a45ecc
--- /dev/null
+++ b/drivers/serial/serial_litex.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 Antony Pavlov <antonynpavlov@xxxxxxxxx>
+ *
+ */
+
+#include <common.h>
+#include <init.h>
+#include <io.h>
+
+#define UART_RXTX 0x00
+#define UART_TXFULL 0x04
+#define UART_RXEMPTY 0x08
+#define UART_EV_PENDING 0x10
+#define UART_EV_RX (1 << 1)
+
+static inline uint32_t litex_serial_readb(struct console_device *cdev,
+ uint32_t offset)
+{
+ void __iomem *base = cdev->dev->priv;
+
+ return readb(base + offset);
+}
+
+static inline void litex_serial_writeb(struct console_device *cdev,
+ uint32_t value, uint32_t offset)
+{
+ void __iomem *base = cdev->dev->priv;
+
+ writeb(value, base + offset);
+}
+
+static void litex_serial_putc(struct console_device *cdev, char c)
+{
+ while (litex_serial_readb(cdev, UART_TXFULL))
+ ;
+
+ litex_serial_writeb(cdev, c, UART_RXTX);
+}
+
+static int litex_serial_getc(struct console_device *cdev)
+{
+ int c;
+
+ while (litex_serial_readb(cdev, UART_RXEMPTY))
+ ;
+
+ c = litex_serial_readb(cdev, UART_RXTX);
+
+ /* refresh UART_RXEMPTY by writing UART_EV_RX to UART_EV_PENDING */
+ litex_serial_writeb(cdev, UART_EV_RX, UART_EV_PENDING);
+
+ return c;
+}
+
+static int litex_serial_tstc(struct console_device *cdev)
+{
+ return !litex_serial_readb(cdev, UART_RXEMPTY);
+}
+
+static int litex_serial_probe(struct device_d *dev)
+{
+ struct resource *iores;
+ struct console_device *cdev;
+
+ cdev = xzalloc(sizeof(struct console_device));
+ iores = dev_request_mem_resource(dev, 0);
+ if (IS_ERR(iores))
+ return PTR_ERR(iores);
+
+ dev->priv = IOMEM(iores->start);
+ cdev->dev = dev;
+ cdev->tstc = &litex_serial_tstc;
+ cdev->putc = &litex_serial_putc;
+ cdev->getc = &litex_serial_getc;
+ cdev->setbrg = NULL;
+
+ console_register(cdev);
+
+ return 0;
+}
+
+static __maybe_unused struct of_device_id litex_serial_dt_ids[] = {
+ {
+ .compatible = "litex,uart",
+ }, {
+ /* sentinel */
+ }
+};
+
+static struct driver_d litex_serial_driver = {
+ .name = "litex-uart",
+ .probe = litex_serial_probe,
+ .of_compatible = DRV_OF_COMPAT(litex_serial_dt_ids),
+};
+console_platform_driver(litex_serial_driver);
--
2.31.1
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