From: Peng Fan <peng....@nxp.com> The i.MX LPUART Documentation: https://www.nxp.com/webapp/Download?colCode=IMX8QMIEC Chatper 13.6 Low Power Universal Asynchronous Receiver/ Transmitter (LPUART)
Tested-by: Henry Wang <henry.w...@arm.com> Signed-off-by: Peng Fan <peng....@nxp.com> --- xen/arch/arm/include/asm/imx-lpuart.h | 64 ++++++ xen/drivers/char/Kconfig | 7 + xen/drivers/char/Makefile | 1 + xen/drivers/char/imx-lpuart.c | 275 ++++++++++++++++++++++++++ 4 files changed, 347 insertions(+) create mode 100644 xen/arch/arm/include/asm/imx-lpuart.h create mode 100644 xen/drivers/char/imx-lpuart.c diff --git a/xen/arch/arm/include/asm/imx-lpuart.h b/xen/arch/arm/include/asm/imx-lpuart.h new file mode 100644 index 0000000000..fe859045dc --- /dev/null +++ b/xen/arch/arm/include/asm/imx-lpuart.h @@ -0,0 +1,64 @@ +/* + * xen/arch/arm/include/asm/imx-lpuart.h + * + * Common constant definition between early printk and the LPUART driver + * + * Peng Fan <peng....@nxp.com> + * Copyright 2022 NXP + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef __ASM_ARM_IMX_LPUART_H__ +#define __ASM_ARM_IMX_LPUART_H__ + +/* 32-bit register definition */ +#define UARTBAUD (0x10) +#define UARTSTAT (0x14) +#define UARTCTRL (0x18) +#define UARTDATA (0x1C) +#define UARTMATCH (0x20) +#define UARTMODIR (0x24) +#define UARTFIFO (0x28) +#define UARTWATER (0x2c) + +#define UARTSTAT_TDRE BIT(23, UL) +#define UARTSTAT_TC BIT(22, UL) +#define UARTSTAT_RDRF BIT(21, UL) +#define UARTSTAT_OR BIT(19, UL) + +#define UARTBAUD_OSR_SHIFT (24) +#define UARTBAUD_OSR_MASK (0x1f) +#define UARTBAUD_SBR_MASK (0x1fff) +#define UARTBAUD_BOTHEDGE (0x00020000) +#define UARTBAUD_TDMAE (0x00800000) +#define UARTBAUD_RDMAE (0x00200000) + +#define UARTCTRL_TIE BIT(23, UL) +#define UARTCTRL_TCIE BIT(22, UL) +#define UARTCTRL_RIE BIT(21, UL) +#define UARTCTRL_ILIE BIT(20, UL) +#define UARTCTRL_TE BIT(19, UL) +#define UARTCTRL_RE BIT(18, UL) +#define UARTCTRL_M BIT(4, UL) + +#define UARTWATER_RXCNT_OFF 24 + +#endif /* __ASM_ARM_IMX_LPUART_H__ */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig index 2ff5b288e2..e5f7b1d8eb 100644 --- a/xen/drivers/char/Kconfig +++ b/xen/drivers/char/Kconfig @@ -13,6 +13,13 @@ config HAS_CADENCE_UART This selects the Xilinx Zynq Cadence UART. If you have a Xilinx Zynq based board, say Y. +config HAS_IMX_LPUART + bool "i.MX LPUART driver" + default y + depends on ARM_64 + help + This selects the i.MX LPUART. If you have i.MX8QM based board, say Y. + config HAS_MVEBU bool "Marvell MVEBU UART driver" default y diff --git a/xen/drivers/char/Makefile b/xen/drivers/char/Makefile index 7c646d771c..14e67cf072 100644 --- a/xen/drivers/char/Makefile +++ b/xen/drivers/char/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_HAS_MVEBU) += mvebu-uart.o obj-$(CONFIG_HAS_OMAP) += omap-uart.o obj-$(CONFIG_HAS_SCIF) += scif-uart.o obj-$(CONFIG_HAS_EHCI) += ehci-dbgp.o +obj-$(CONFIG_HAS_IMX_LPUART) += imx-lpuart.o obj-$(CONFIG_ARM) += arm-uart.o obj-y += serial.o obj-$(CONFIG_XEN_GUEST) += xen_pv_console.o diff --git a/xen/drivers/char/imx-lpuart.c b/xen/drivers/char/imx-lpuart.c new file mode 100644 index 0000000000..2709136081 --- /dev/null +++ b/xen/drivers/char/imx-lpuart.c @@ -0,0 +1,275 @@ +/* + * xen/drivers/char/imx-lpuart.c + * + * Driver for i.MX LPUART. + * + * Peng Fan <peng....@nxp.com> + * Copyright 2022 NXP + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <xen/errno.h> +#include <xen/init.h> +#include <xen/irq.h> +#include <xen/mm.h> +#include <xen/serial.h> +#include <asm/device.h> +#include <asm/imx-lpuart.h> +#include <asm/io.h> + +#define imx_lpuart_read(uart, off) readl((uart)->regs + off) +#define imx_lpuart_write(uart, off, val) writel((val), (uart)->regs + off) + +static struct imx_lpuart { + uint32_t baud, clock_hz, data_bits, parity, stop_bits, fifo_size; + uint32_t irq; + char __iomem *regs; + struct irqaction irqaction; + struct vuart_info vuart; +} imx8_com; + +static void imx_lpuart_interrupt(int irq, void *data, + struct cpu_user_regs *regs) +{ + struct serial_port *port = data; + struct imx_lpuart *uart = port->uart; + uint32_t sts, rxcnt; + + sts = imx_lpuart_read(uart, UARTSTAT); + rxcnt = imx_lpuart_read(uart, UARTWATER) >> UARTWATER_RXCNT_OFF; + + if ( (sts & UARTSTAT_RDRF) || (rxcnt > 0) ) + serial_rx_interrupt(port, regs); + + if ( sts & UARTSTAT_TDRE ) + serial_tx_interrupt(port, regs); + + imx_lpuart_write(uart, UARTSTAT, sts); +} + +static void __init imx_lpuart_init_preirq(struct serial_port *port) +{ + struct imx_lpuart *uart = port->uart; + uint32_t ctrl, old_ctrl, bd; + + old_ctrl = imx_lpuart_read(uart, UARTCTRL); + ctrl = (old_ctrl & ~UARTCTRL_M) | UARTCTRL_TE | UARTCTRL_RE; + bd = imx_lpuart_read(uart, UARTBAUD); + + while ( !(imx_lpuart_read(uart, UARTSTAT) & UARTSTAT_TC) ) + cpu_relax(); + + /* Disable transmit and receive */ + imx_lpuart_write(uart, UARTCTRL, old_ctrl & ~(UARTCTRL_TE | UARTCTRL_RE)); + + /* Reuse firmware baudrate settings, only disable DMA here */ + bd &= ~(UARTBAUD_TDMAE | UARTBAUD_RDMAE); + + imx_lpuart_write(uart, UARTMODIR, 0); + imx_lpuart_write(uart, UARTBAUD, bd); + imx_lpuart_write(uart, UARTCTRL, ctrl); +} + +static void __init imx_lpuart_init_postirq(struct serial_port *port) +{ + struct imx_lpuart *uart = port->uart; + uint32_t temp; + + uart->irqaction.handler = imx_lpuart_interrupt; + uart->irqaction.name = "imx_lpuart"; + uart->irqaction.dev_id = port; + + if ( setup_irq(uart->irq, 0, &uart->irqaction) != 0 ) + { + dprintk(XENLOG_ERR, "Failed to allocate imx_lpuart IRQ %d\n", + uart->irq); + return; + } + + /* Enable interrupts */ + temp = imx_lpuart_read(uart, UARTCTRL); + temp |= (UARTCTRL_RIE | UARTCTRL_TIE); + temp |= UARTCTRL_ILIE; + imx_lpuart_write(uart, UARTCTRL, temp); +} + +static void imx_lpuart_suspend(struct serial_port *port) +{ + BUG(); +} + +static void imx_lpuart_resume(struct serial_port *port) +{ + BUG(); +} + +static int imx_lpuart_tx_ready(struct serial_port *port) +{ + struct imx_lpuart *uart = port->uart; + + return imx_lpuart_read(uart, UARTSTAT) & UARTSTAT_TC; +} + +static void imx_lpuart_putc(struct serial_port *port, char c) +{ + struct imx_lpuart *uart = port->uart; + + while ( !(imx_lpuart_read(uart, UARTSTAT) & UARTSTAT_TDRE) ) + cpu_relax(); + + imx_lpuart_write(uart, UARTDATA, c); +} + +static int imx_lpuart_getc(struct serial_port *port, char *pc) +{ + struct imx_lpuart *uart = port->uart; + int ch; + + while ( !(imx_lpuart_read(uart, UARTSTAT) & UARTSTAT_RDRF) ) + return 0; + + ch = imx_lpuart_read(uart, UARTDATA); + *pc = ch & 0xff; + + if ( imx_lpuart_read(uart, UARTSTAT) & UARTSTAT_OR ) + imx_lpuart_write(uart, UARTSTAT, UARTSTAT_OR); + + return 1; +} + +static int __init imx_lpuart_irq(struct serial_port *port) +{ + struct imx_lpuart *uart = port->uart; + + return ((uart->irq > 0) ? uart->irq : -1); +} + +static const struct vuart_info *imx_lpuart_vuart_info(struct serial_port *port) +{ + struct imx_lpuart *uart = port->uart; + + return &uart->vuart; +} + +static void imx_lpuart_start_tx(struct serial_port *port) +{ + struct imx_lpuart *uart = port->uart; + uint32_t temp; + + /* Wait until empty */ + while ( !(imx_lpuart_read(uart, UARTSTAT) & UARTSTAT_TDRE) ) + cpu_relax(); + + temp = imx_lpuart_read(uart, UARTCTRL); + imx_lpuart_write(uart, UARTCTRL, (temp | UARTCTRL_TIE)); +} + +static void imx_lpuart_stop_tx(struct serial_port *port) +{ + struct imx_lpuart *uart = port->uart; + uint32_t temp; + + temp = imx_lpuart_read(uart, UARTCTRL); + temp &= ~(UARTCTRL_TIE | UARTCTRL_TCIE); + imx_lpuart_write(uart, UARTCTRL, temp); +} + +static struct uart_driver __read_mostly imx_lpuart_driver = { + .init_preirq = imx_lpuart_init_preirq, + .init_postirq = imx_lpuart_init_postirq, + .endboot = NULL, + .suspend = imx_lpuart_suspend, + .resume = imx_lpuart_resume, + .tx_ready = imx_lpuart_tx_ready, + .putc = imx_lpuart_putc, + .getc = imx_lpuart_getc, + .irq = imx_lpuart_irq, + .start_tx = imx_lpuart_start_tx, + .stop_tx = imx_lpuart_stop_tx, + .vuart_info = imx_lpuart_vuart_info, +}; + +static int __init imx_lpuart_init(struct dt_device_node *dev, + const void *data) +{ + const char *config = data; + struct imx_lpuart *uart; + int res; + u64 addr, size; + + if ( strcmp(config, "") ) + printk("WARNING: UART configuration is not supported\n"); + + uart = &imx8_com; + + uart->baud = 115200; + uart->data_bits = 8; + uart->parity = 0; + uart->stop_bits = 1; + + res = dt_device_get_address(dev, 0, &addr, &size); + if ( res ) + { + printk("imx8-lpuart: Unable to retrieve the base" + " address of the UART\n"); + return res; + } + + res = platform_get_irq(dev, 0); + if ( res < 0 ) + { + printk("imx8-lpuart: Unable to retrieve the IRQ\n"); + return -EINVAL; + } + uart->irq = res; + + uart->regs = ioremap_nocache(addr, size); + if ( !uart->regs ) + { + printk("imx8-lpuart: Unable to map the UART memory\n"); + return -ENOMEM; + } + + uart->vuart.base_addr = addr; + uart->vuart.size = size; + uart->vuart.data_off = UARTDATA; + /* tmp from uboot */ + uart->vuart.status_off = UARTSTAT; + uart->vuart.status = UARTSTAT_TDRE; + + /* Register with generic serial driver */ + serial_register_uart(SERHND_DTUART, &imx_lpuart_driver, uart); + + dt_device_set_used_by(dev, DOMID_XEN); + + return 0; +} + +static const struct dt_device_match imx_lpuart_dt_compat[] __initconst = +{ + DT_MATCH_COMPATIBLE("fsl,imx8qm-lpuart"), + { /* sentinel */ }, +}; + +DT_DEVICE_START(imx_lpuart, "i.MX LPUART", DEVICE_SERIAL) + .dt_match = imx_lpuart_dt_compat, + .init = imx_lpuart_init, +DT_DEVICE_END + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ -- 2.35.1