diff options
Diffstat (limited to 'roms/u-boot/drivers/serial/serial_meson.c')
| -rw-r--r-- | roms/u-boot/drivers/serial/serial_meson.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/serial/serial_meson.c b/roms/u-boot/drivers/serial/serial_meson.c new file mode 100644 index 000000000..d69ec221e --- /dev/null +++ b/roms/u-boot/drivers/serial/serial_meson.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * (C) Copyright 2016 Beniamino Galvani <b.galvani@gmail.com> + */ + +#include <common.h> +#include <dm.h> +#include <errno.h> +#include <fdtdec.h> +#include <linux/bitops.h> +#include <linux/compiler.h> +#include <serial.h> + +struct meson_uart { + u32 wfifo; + u32 rfifo; + u32 control; + u32 status; + u32 misc; +}; + +struct meson_serial_plat { + struct meson_uart *reg; +}; + +/* AML_UART_STATUS bits */ +#define AML_UART_PARITY_ERR BIT(16) +#define AML_UART_FRAME_ERR BIT(17) +#define AML_UART_TX_FIFO_WERR BIT(18) +#define AML_UART_RX_EMPTY BIT(20) +#define AML_UART_TX_FULL BIT(21) +#define AML_UART_TX_EMPTY BIT(22) +#define AML_UART_XMIT_BUSY BIT(25) +#define AML_UART_ERR (AML_UART_PARITY_ERR | \ + AML_UART_FRAME_ERR | \ + AML_UART_TX_FIFO_WERR) + +/* AML_UART_CONTROL bits */ +#define AML_UART_TX_EN BIT(12) +#define AML_UART_RX_EN BIT(13) +#define AML_UART_TX_RST BIT(22) +#define AML_UART_RX_RST BIT(23) +#define AML_UART_CLR_ERR BIT(24) + +static void meson_serial_init(struct meson_uart *uart) +{ + u32 val; + + val = readl(&uart->control); + val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR); + writel(val, &uart->control); + val &= ~(AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR); + writel(val, &uart->control); + val |= (AML_UART_RX_EN | AML_UART_TX_EN); + writel(val, &uart->control); +} + +static int meson_serial_probe(struct udevice *dev) +{ + struct meson_serial_plat *plat = dev_get_plat(dev); + struct meson_uart *const uart = plat->reg; + + meson_serial_init(uart); + + return 0; +} + +static void meson_serial_rx_error(struct udevice *dev) +{ + struct meson_serial_plat *plat = dev_get_plat(dev); + struct meson_uart *const uart = plat->reg; + u32 val = readl(&uart->control); + + /* Clear error */ + val |= AML_UART_CLR_ERR; + writel(val, &uart->control); + val &= ~AML_UART_CLR_ERR; + writel(val, &uart->control); + + /* Remove spurious byte from fifo */ + readl(&uart->rfifo); +} + +static int meson_serial_getc(struct udevice *dev) +{ + struct meson_serial_plat *plat = dev_get_plat(dev); + struct meson_uart *const uart = plat->reg; + uint32_t status = readl(&uart->status); + + if (status & AML_UART_RX_EMPTY) + return -EAGAIN; + + if (status & AML_UART_ERR) { + meson_serial_rx_error(dev); + return -EIO; + } + + return readl(&uart->rfifo) & 0xff; +} + +static int meson_serial_putc(struct udevice *dev, const char ch) +{ + struct meson_serial_plat *plat = dev_get_plat(dev); + struct meson_uart *const uart = plat->reg; + + if (readl(&uart->status) & AML_UART_TX_FULL) + return -EAGAIN; + + writel(ch, &uart->wfifo); + + return 0; +} + +static int meson_serial_pending(struct udevice *dev, bool input) +{ + struct meson_serial_plat *plat = dev_get_plat(dev); + struct meson_uart *const uart = plat->reg; + uint32_t status = readl(&uart->status); + + if (input) { + if (status & AML_UART_RX_EMPTY) + return false; + + /* + * Handle and drop any RX error here to avoid + * returning true here when an error byte is in the FIFO + */ + if (status & AML_UART_ERR) { + meson_serial_rx_error(dev); + return false; + } + + return true; + } else { + return !(status & AML_UART_TX_FULL); + } +} + +static int meson_serial_of_to_plat(struct udevice *dev) +{ + struct meson_serial_plat *plat = dev_get_plat(dev); + fdt_addr_t addr; + + addr = dev_read_addr(dev); + if (addr == FDT_ADDR_T_NONE) + return -EINVAL; + + plat->reg = (struct meson_uart *)addr; + + return 0; +} + +static const struct dm_serial_ops meson_serial_ops = { + .putc = meson_serial_putc, + .pending = meson_serial_pending, + .getc = meson_serial_getc, +}; + +static const struct udevice_id meson_serial_ids[] = { + { .compatible = "amlogic,meson-uart" }, + { .compatible = "amlogic,meson-gx-uart" }, + { } +}; + +U_BOOT_DRIVER(serial_meson) = { + .name = "serial_meson", + .id = UCLASS_SERIAL, + .of_match = meson_serial_ids, + .probe = meson_serial_probe, + .ops = &meson_serial_ops, + .of_to_plat = meson_serial_of_to_plat, + .plat_auto = sizeof(struct meson_serial_plat), +}; + +#ifdef CONFIG_DEBUG_UART_MESON + +#include <debug_uart.h> + +static inline void _debug_uart_init(void) +{ +} + +static inline void _debug_uart_putc(int ch) +{ + struct meson_uart *regs = (struct meson_uart *)CONFIG_DEBUG_UART_BASE; + + while (readl(®s->status) & AML_UART_TX_FULL) + ; + + writel(ch, ®s->wfifo); +} + +DEBUG_UART_FUNCS + +#endif |