Acked-by: Angelo Dureghello <[email protected]> On 1/5/26 17:52, Kuan-Wei Chiu wrote: > Add support for the Google Goldfish TTY serial device. This virtual > device is commonly used in QEMU virtual machines (such as the m68k > virt machine) and Android emulators. > > The driver implements basic console output and input polling using the > Goldfish MMIO interface. > > Signed-off-by: Kuan-Wei Chiu <[email protected]> > Reviewed-by: Yao Zi <[email protected]> > Tested-by: Daniel Palmer <[email protected]> > Acked-by: Heinrich Schuchardt <[email protected]> > --- > Changes in v5: > - Rebase on u-boot/next branch. > > MAINTAINERS | 6 ++ > drivers/serial/Kconfig | 8 +++ > drivers/serial/Makefile | 1 + > drivers/serial/serial_goldfish.c | 109 +++++++++++++++++++++++++++++++ > include/goldfish_tty.h | 18 +++++ > 5 files changed, 142 insertions(+) > create mode 100644 drivers/serial/serial_goldfish.c > create mode 100644 include/goldfish_tty.h > > diff --git a/MAINTAINERS b/MAINTAINERS > index 27ce73d83f4..8f884ff495a 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -1260,6 +1260,12 @@ S: Maintained > F: drivers/misc/gsc.c > F: include/gsc.h > > +GOLDFISH SERIAL DRIVER > +M: Kuan-Wei Chiu <[email protected]> > +S: Maintained > +F: drivers/serial/serial_goldfish.c > +F: include/goldfish_tty.h > + > INTERCONNECT: > M: Neil Armstrong <[email protected]> > S: Maintained > diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig > index 371d7aa5bba..b84cb9ec781 100644 > --- a/drivers/serial/Kconfig > +++ b/drivers/serial/Kconfig > @@ -1193,4 +1193,12 @@ config SYS_SDMR > depends on MPC8XX_CONS > default 0x0 > > +config SERIAL_GOLDFISH > + bool "Goldfish TTY support" > + depends on DM_SERIAL > + help > + Select this to enable support for the Goldfish TTY serial port. > + This virtual device is commonly used by QEMU virtual machines > + (e.g. m68k virt) for console output. > + > endif > diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile > index 8eaae62b0fc..fe8d23be512 100644 > --- a/drivers/serial/Makefile > +++ b/drivers/serial/Makefile > @@ -63,3 +63,4 @@ obj-$(CONFIG_XTENSA_SEMIHOSTING_SERIAL) += > serial_xtensa_semihosting.o > obj-$(CONFIG_S5P4418_PL011_SERIAL) += serial_s5p4418_pl011.o > > obj-$(CONFIG_UART4_SERIAL) += serial_adi_uart4.o > +obj-$(CONFIG_SERIAL_GOLDFISH) += serial_goldfish.o > diff --git a/drivers/serial/serial_goldfish.c > b/drivers/serial/serial_goldfish.c > new file mode 100644 > index 00000000000..278d0cf3e0d > --- /dev/null > +++ b/drivers/serial/serial_goldfish.c > @@ -0,0 +1,109 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Copyright (C) 2025, Kuan-Wei Chiu <[email protected]> > + * Goldfish TTY driver for U-Boot > + */ > + > +#include <asm/io.h> > +#include <dm.h> > +#include <goldfish_tty.h> > +#include <linux/types.h> > +#include <mapmem.h> > +#include <serial.h> > + > +/* Goldfish TTY Register Offsets */ > +#define GOLDFISH_TTY_PUT_CHAR 0x00 > +#define GOLDFISH_TTY_BYTES_READY 0x04 > +#define GOLDFISH_TTY_CMD 0x08 > +#define GOLDFISH_TTY_DATA_PTR 0x10 > +#define GOLDFISH_TTY_DATA_LEN 0x14 > +#define GOLDFISH_TTY_DATA_PTR_HIGH 0x18 > +#define GOLDFISH_TTY_VERSION 0x20 > + > +/* Commands */ > +#define CMD_WRITE_BUFFER 2 > +#define CMD_READ_BUFFER 3 > + > +struct goldfish_tty_priv { > + void __iomem *base; > + u8 rx_buf; > +}; > + > +static int goldfish_serial_getc(struct udevice *dev) > +{ > + struct goldfish_tty_priv *priv = dev_get_priv(dev); > + unsigned long paddr; > + u32 count; > + > + count = __raw_readl(priv->base + GOLDFISH_TTY_BYTES_READY); > + if (count == 0) > + return -EAGAIN; > + > + paddr = virt_to_phys((void *)&priv->rx_buf); > + > + __raw_writel(0, priv->base + GOLDFISH_TTY_DATA_PTR_HIGH); > + __raw_writel(paddr, priv->base + GOLDFISH_TTY_DATA_PTR); > + __raw_writel(1, priv->base + GOLDFISH_TTY_DATA_LEN); > + __raw_writel(CMD_READ_BUFFER, priv->base + GOLDFISH_TTY_CMD); > + > + return priv->rx_buf; > +} > + > +static int goldfish_serial_putc(struct udevice *dev, const char ch) > +{ > + struct goldfish_tty_priv *priv = dev_get_priv(dev); > + > + __raw_writel(ch, priv->base + GOLDFISH_TTY_PUT_CHAR); > + > + return 0; > +} > + > +static int goldfish_serial_pending(struct udevice *dev, bool input) > +{ > + struct goldfish_tty_priv *priv = dev_get_priv(dev); > + > + if (input) > + return __raw_readl(priv->base + GOLDFISH_TTY_BYTES_READY); > + > + return 0; > +} > + > +static int goldfish_serial_probe(struct udevice *dev) > +{ > + struct goldfish_tty_priv *priv = dev_get_priv(dev); > + struct goldfish_tty_plat *plat = dev_get_plat(dev); > + fdt_addr_t addr; > + > + addr = dev_read_addr(dev); > + if (addr != FDT_ADDR_T_NONE) { > + priv->base = map_sysmem(addr, 0x1000); > + } else { > + plat = dev_get_plat(dev); > + if (!plat) > + return -EINVAL; > + priv->base = plat->base; > + } > + > + return 0; > +} > + > +static const struct dm_serial_ops goldfish_serial_ops = { > + .putc = goldfish_serial_putc, > + .pending = goldfish_serial_pending, > + .getc = goldfish_serial_getc, > +}; > + > +static const struct udevice_id goldfish_serial_ids[] = { > + { .compatible = "google,goldfish-tty" }, > + { } > +}; > + > +U_BOOT_DRIVER(serial_goldfish) = { > + .name = "serial_goldfish", > + .id = UCLASS_SERIAL, > + .of_match = goldfish_serial_ids, > + .probe = goldfish_serial_probe, > + .ops = &goldfish_serial_ops, > + .priv_auto = sizeof(struct goldfish_tty_priv), > + .flags = DM_FLAG_PRE_RELOC, > +}; > diff --git a/include/goldfish_tty.h b/include/goldfish_tty.h > new file mode 100644 > index 00000000000..8777da4942d > --- /dev/null > +++ b/include/goldfish_tty.h > @@ -0,0 +1,18 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * Copyright (C) 2025, Kuan-Wei Chiu <[email protected]> > + */ > + > +#ifndef _GOLDFISH_TTY_H_ > +#define _GOLDFISH_TTY_H_ > + > +#include <linux/types.h> > + > +/* Platform data for the Goldfish TTY driver > + * Used to pass hardware base address from Board to Driver > + */ > +struct goldfish_tty_plat { > + void __iomem *base; > +}; > + > +#endif /* _GOLDFISH_TTY_H_ */
-- Angelo
