Signed-off-by: Antony Pavlov <[email protected]> --- 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 <[email protected]> + * + */ + +#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); -- 2.32.0 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
