| Message ID | 20240402120557.1822253-3-olekstysh@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Add UART support for i.MX 8M Mini EVKB | expand |
Hi Oleksandr, On 02/04/2024 14:05, Oleksandr Tyshchenko wrote: > > > From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > > The i.MX UART Documentation: > https://www.nxp.com/webapp/Download?colCode=IMX8MMRM > Chapter 16.2 Universal Asynchronous Receiver/Transmitter (UART) > > Tested on i.MX 8M Mini only, but I guess, it should be imperative mood > suitable for other i.MX8M* SoCs (those UART device tree nodes > contain "fsl,imx6q-uart" compatible string). > > Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > --- > I used the "earlycon=ec_imx6q,0x30890000" cmd arg and > selected CONFIG_SERIAL_IMX_EARLYCON in Linux for enabling vUART. > --- > --- > MAINTAINERS | 1 + > xen/drivers/char/Kconfig | 7 + > xen/drivers/char/Makefile | 1 + > xen/drivers/char/imx-uart.c | 299 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 308 insertions(+) > create mode 100644 xen/drivers/char/imx-uart.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 1bd22fd75f..bd4084fd20 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -249,6 +249,7 @@ F: xen/drivers/char/arm-uart.c > F: xen/drivers/char/cadence-uart.c > F: xen/drivers/char/exynos4210-uart.c > F: xen/drivers/char/imx-lpuart.c > +F: xen/drivers/char/imx-uart.c > F: xen/drivers/char/meson-uart.c > F: xen/drivers/char/mvebu-uart.c > F: xen/drivers/char/omap-uart.c > diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig > index e18ec3788c..f51a1f596a 100644 > --- a/xen/drivers/char/Kconfig > +++ b/xen/drivers/char/Kconfig > @@ -20,6 +20,13 @@ config HAS_IMX_LPUART > help > This selects the i.MX LPUART. If you have i.MX8QM based board, say Y. > > +config HAS_IMX_UART > + bool "i.MX UART driver" > + default y > + depends on ARM_64 > + help > + This selects the i.MX UART. If you have i.MX8M* 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 e7e374775d..147530a1ed 100644 > --- a/xen/drivers/char/Makefile > +++ b/xen/drivers/char/Makefile > @@ -10,6 +10,7 @@ obj-$(CONFIG_HAS_SCIF) += scif-uart.o > obj-$(CONFIG_HAS_EHCI) += ehci-dbgp.o > obj-$(CONFIG_XHCI) += xhci-dbc.o > obj-$(CONFIG_HAS_IMX_LPUART) += imx-lpuart.o > +obj-$(CONFIG_HAS_IMX_UART) += imx-uart.o > obj-$(CONFIG_ARM) += arm-uart.o > obj-y += serial.o > obj-$(CONFIG_XEN_GUEST) += xen_pv_console.o > diff --git a/xen/drivers/char/imx-uart.c b/xen/drivers/char/imx-uart.c > new file mode 100644 > index 0000000000..13bb189063 > --- /dev/null > +++ b/xen/drivers/char/imx-uart.c > @@ -0,0 +1,299 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ Can it be GPL-2.0-only? Some companies are worried about v3. > +/* > + * xen/drivers/char/imx-uart.c > + * > + * Driver for i.MX UART. > + * > + * Based on Linux's drivers/tty/serial/imx.c > + * > + * Copyright (C) 2024 EPAM Systems Inc. > + */ > + > +#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-uart.h> > +#include <asm/io.h> > + > +#define imx_uart_read(uart, off) readl((uart)->regs + (off)) > +#define imx_uart_write(uart, off, val) writel((val), (uart)->regs + (off)) > + > +static struct imx_uart { > + uint32_t baud, clock_hz, data_bits, parity, stop_bits, fifo_size; What's the use of these variables? AFAICT they are set but never used. > + uint32_t irq; unsigned int > + char __iomem *regs; > + struct irqaction irqaction; > + struct vuart_info vuart; > +} imx_com; > + > +static void imx_uart_interrupt(int irq, void *data) > +{ > + struct serial_port *port = data; > + struct imx_uart *uart = port->uart; > + uint32_t usr1, usr2; > + > + usr1 = imx_uart_read(uart, USR1); > + usr2 = imx_uart_read(uart, USR2); > + > + if ( usr1 & (USR1_RRDY | USR1_AGTIM) ) > + { > + imx_uart_write(uart, USR1, USR1_AGTIM); > + serial_rx_interrupt(port); > + } > + > + if ( (usr1 & USR1_TRDY) || (usr2 & USR2_TXDC) ) > + serial_tx_interrupt(port); > +} > + > +static void imx_uart_clear_rx_errors(struct serial_port *port) > +{ > + struct imx_uart *uart = port->uart; > + uint32_t usr1, usr2; > + > + usr1 = imx_uart_read(uart, USR1); > + usr2 = imx_uart_read(uart, USR2); > + > + if ( usr2 & USR2_BRCD ) > + imx_uart_write(uart, USR2, USR2_BRCD); > + else if ( usr1 & USR1_FRAMERR ) > + imx_uart_write(uart, USR1, USR1_FRAMERR); > + else if ( usr1 & USR1_PARITYERR ) > + imx_uart_write(uart, USR1, USR1_PARITYERR); > + > + if ( usr2 & USR2_ORE ) > + imx_uart_write(uart, USR2, USR2_ORE); > +} > + > +static void __init imx_uart_init_preirq(struct serial_port *port) > +{ > + struct imx_uart *uart = port->uart; > + uint32_t reg; > + > + /* > + * Wait for the transmission to complete. This is needed for a smooth > + * transition when we come from early printk. > + */ > + while ( !(imx_uart_read(uart, USR2) & USR2_TXDC) ) > + cpu_relax(); > + > + /* Set receiver/transmitter trigger level */ > + reg = imx_uart_read(uart, UFCR); > + reg &= (UFCR_RFDIV | UFCR_DCEDTE); > + reg |= TXTL_DEFAULT << UFCR_TXTL_SHF | RXTL_DEFAULT; please surround TXTL_DEFAULT << UFCR_TXTL_SHF with parentheses > + imx_uart_write(uart, UFCR, reg); > + > + /* Enable UART and disable interrupts/DMA */ > + reg = imx_uart_read(uart, UCR1); > + reg |= UCR1_UARTEN; > + reg &= ~(UCR1_TRDYEN | UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN | > + UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN); > + imx_uart_write(uart, UCR1, reg); > + > + /* Enable receiver/transmitter and disable Aging Timer */ > + reg = imx_uart_read(uart, UCR2); > + reg |= UCR2_RXEN | UCR2_TXEN; > + reg &= ~UCR2_ATEN; > + imx_uart_write(uart, UCR2, reg); > + > + /* Disable interrupts */ > + reg = imx_uart_read(uart, UCR4); > + reg &= ~(UCR4_TCEN | UCR4_DREN); > + imx_uart_write(uart, UCR4, reg); > +} > + > +static void __init imx_uart_init_postirq(struct serial_port *port) > +{ > + struct imx_uart *uart = port->uart; > + > + uart->irqaction.handler = imx_uart_interrupt; > + uart->irqaction.name = "imx_uart"; > + uart->irqaction.dev_id = port; > + > + if ( setup_irq(uart->irq, 0, &uart->irqaction) != 0 ) > + { > + dprintk(XENLOG_ERR, "Failed to allocate imx_uart IRQ %d\n", uart->irq); Wrong format specifier for unsigned, use %u Also, why dprintk? > + return; > + } > + > + /* Clear possible receiver errors */ > + imx_uart_clear_rx_errors(port); > + > + /* Enable interrupts */ > + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) | > + UCR1_RRDYEN | UCR1_TRDYEN); > + imx_uart_write(uart, UCR2, imx_uart_read(uart, UCR2) | UCR2_ATEN); > +} > + > +static void imx_uart_suspend(struct serial_port *port) > +{ > + BUG(); > +} no need for this function > + > +static void imx_uart_resume(struct serial_port *port) > +{ > + BUG(); > +} no need for this function > + > +static int imx_uart_tx_ready(struct serial_port *port) > +{ > + struct imx_uart *uart = port->uart; can be const > + uint32_t reg; > + > + reg = imx_uart_read(uart, IMX21_UTS); > + if ( reg & UTS_TXEMPTY ) > + return TX_FIFO_SIZE; empty line here please > + if ( reg & UTS_TXFULL ) > + return 0; > + > + /* > + * If the FIFO is neither full nor empty then there is a space for > + * one char at least. > + */ > + return 1; > +} > + > +static void imx_uart_putc(struct serial_port *port, char c) > +{ > + struct imx_uart *uart = port->uart; can be const > + > + while ( imx_uart_read(uart, IMX21_UTS) & UTS_TXFULL ) > + cpu_relax(); Looking at pl011, cdns, putc contains only a write to data register. This is because ->putc always follows ->tx_ready which contains the check for how many chars can be written. Therefore, AFAICT this should be dropped. > + > + imx_uart_write(uart, URTX0, c); > +} > + > +static int imx_uart_getc(struct serial_port *port, char *pc) > +{ > + struct imx_uart *uart = port->uart; can be const > + uint32_t data; > + > + if ( !(imx_uart_read(uart, USR2) & USR2_RDR) ) > + return 0; > + > + data = imx_uart_read(uart, URXD0); > + *pc = data & URXD_RX_DATA; > + > + if ( unlikely(data & URXD_ERR) ) > + imx_uart_clear_rx_errors(port); > + > + return 1; > +} > + > +static int __init imx_uart_irq(struct serial_port *port) > +{ > + struct imx_uart *uart = port->uart; can be const > + > + return ((uart->irq > 0) ? uart->irq : -1); > +} > + > +static const struct vuart_info *imx_uart_vuart_info(struct serial_port *port) > +{ > + struct imx_uart *uart = port->uart; can be const > + > + return &uart->vuart; > +} > + > +static void imx_uart_start_tx(struct serial_port *port) > +{ > + struct imx_uart *uart = port->uart; > + > + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) | UCR1_TRDYEN); > +} > + > +static void imx_uart_stop_tx(struct serial_port *port) > +{ > + struct imx_uart *uart = port->uart; > + > + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) & ~UCR1_TRDYEN); > +} > + > +static struct uart_driver __read_mostly imx_uart_driver = { > + .init_preirq = imx_uart_init_preirq, > + .init_postirq = imx_uart_init_postirq, > + .endboot = NULL, > + .suspend = imx_uart_suspend, > + .resume = imx_uart_resume, no need to assign a value for these 3 members > + .tx_ready = imx_uart_tx_ready, > + .putc = imx_uart_putc, > + .getc = imx_uart_getc, > + .irq = imx_uart_irq, > + .start_tx = imx_uart_start_tx, > + .stop_tx = imx_uart_stop_tx, > + .vuart_info = imx_uart_vuart_info, > +}; > + > +static int __init imx_uart_init(struct dt_device_node *dev, const void *data) > +{ > + const char *config = data; > + struct imx_uart *uart; > + int res; > + paddr_t addr, size; > + > + if ( strcmp(config, "") ) > + printk("WARNING: UART configuration is not supported\n"); > + > + uart = &imx_com; > + > + uart->baud = 115200; > + uart->data_bits = 8; > + uart->parity = 0; > + uart->stop_bits = 1; They are set but never used > + > + res = dt_device_get_paddr(dev, 0, &addr, &size); > + if ( res ) > + { > + printk("imx-uart: Unable to retrieve the base address of the UART\n"); > + return res; > + } > + > + res = platform_get_irq(dev, 0); > + if ( res < 0 ) > + { > + printk("imx-uart: Unable to retrieve the IRQ\n"); > + return -EINVAL; > + } > + uart->irq = res; > + > + uart->regs = ioremap_nocache(addr, size); > + if ( !uart->regs ) > + { > + printk("imx-uart: Unable to map the UART memory\n"); > + return -ENOMEM; > + } > + > + uart->vuart.base_addr = addr; > + uart->vuart.size = size; > + uart->vuart.data_off = URTX0; > + uart->vuart.status_off = IMX21_UTS; > + uart->vuart.status = UTS_TXEMPTY; > + > + /* Register with generic serial driver */ > + serial_register_uart(SERHND_DTUART, &imx_uart_driver, uart); > + > + dt_device_set_used_by(dev, DOMID_XEN); > + > + return 0; > +} > + > +static const struct dt_device_match imx_uart_dt_compat[] __initconst = > +{ > + DT_MATCH_COMPATIBLE("fsl,imx6q-uart"), > + { /* sentinel */ }, > +}; > + > +DT_DEVICE_START(imx_uart, "i.MX UART", DEVICE_SERIAL) > + .dt_match = imx_uart_dt_compat, > + .init = imx_uart_init, > +DT_DEVICE_END > + > +/* > + * Local variables: > + * mode: C > + * c-file-style: "BSD" > + * c-basic-offset: 4 > + * indent-tabs-mode: nil > + * End: > + */ > -- > 2.34.1 > ~Michal
Hi Oleksandr, > Subject: [PATCH 2/2] xen/arm: Add i.MX UART driver > > From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > > The i.MX UART Documentation: > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww. > nxp.com%2Fwebapp%2FDownload%3FcolCode%3DIMX8MMRM&data=05%7 > C02%7Cpeng.fan%40nxp.com%7C6ada06c4133849667f3608dc530d5471%7 > C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6384765639197564 > 70%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz > IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=RmXgAMb7 > wFZ7epZgYgHJo4LH35rzQhD05yTXSkttXbc%3D&reserved=0 > Chapter 16.2 Universal Asynchronous Receiver/Transmitter (UART) > > Tested on i.MX 8M Mini only, but I guess, it should be suitable for other > i.MX8M* SoCs (those UART device tree nodes contain "fsl,imx6q-uart" > compatible string). Good to see people are interested in XEN on 8M. I had an implementation back in 2015, you could take a look. #include <xen/config.h> #include <xen/console.h> #include <xen/serial.h> #include <xen/init.h> #include <xen/irq.h> #include <xen/device_tree.h> #include <asm/device.h> #include <xen/errno.h> #include <xen/mm.h> #include <xen/vmap.h> #include <asm/imx-uart.h> #include <asm/io.h> #define imx_read(uart, off) readl((uart)->regs + off) #define imx_write(uart, off, val) writel((val), (uart)->regs + off) #define CONFIG_IMX8_ZEBU static struct imx_uart { unsigned int baud, clock_hz, data_bits, parity, stop_bits, fifo_size; unsigned int irq; char __iomem *regs; struct irqaction irqaction; struct vuart_info vuart; } imx_com = {0}; static void imx_uart_interrupt(int irq, void *data, struct cpu_user_regs *regs) { struct serial_port *port = data; struct imx_uart *uart = port->uart; unsigned int sts, sts2; sts = imx_read(uart, USR1); if ((sts & USR1_RRDY) || (sts & USR1_AGTIM)) { if (sts & USR1_AGTIM) imx_write(uart, USR1, USR1_AGTIM); serial_rx_interrupt(port, regs); } if ((sts & USR1_TRDY) && (imx_read(uart, UCR1) & UCR1_TXMPTYEN)) { serial_tx_interrupt(port, regs); } if (sts & USR1_AWAKE) { imx_write(uart, USR1, USR1_AWAKE); } if (sts & USR1_AIRINT) { imx_write(uart, USR1, USR1_AIRINT); } sts2 = imx_read(uart, USR2); if (sts2 & USR2_ORE) { dprintk(XENLOG_ERR, "uart: rxfifo overrun\n"); imx_write(uart, USR2, sts2 | USR2_ORE); } } static void __init imx_uart_init_preirq(struct serial_port *port) { struct imx_uart *uart = port->uart; int val; dprintk(XENLOG_ERR, "10\n"); imx_write(uart, USR1, USR1_RTSD); dprintk(XENLOG_ERR, "12\n"); val = imx_read(uart, UCR1); val |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN; imx_write(uart, UCR1, val); dprintk(XENLOG_ERR, "13\n"); val = imx_read(uart, UCR2); val |= UCR2_RXEN | UCR2_TXEN | UCR2_IRTS; imx_write(uart, UCR2, val); //#ifdef CONFIG_IMX8_ZEBU #if 0 imx_write(uart, UFCR, (2U << 10) | (5U << 7) || (0U << 6) | (1U << 0)); #else #define TXTL 2 /* reset default */ #define RXTL 1 /* For console port */ #define RXTL_UART 16 /* For uart */ val = imx_read(uart, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE); val |= TXTL << UFCR_TXTL_SHF | RXTL; imx_write(uart, UFCR, val); #endif dprintk(XENLOG_ERR, "14\n"); dprintk(XENLOG_ERR, "===============UFCR USR1 %x %x\n", imx_read(uart, UFCR), imx_read(uart, USR1)); } static void __init imx_uart_init_postirq(struct serial_port *port) { struct imx_uart *uart = port->uart; dprintk(XENLOG_ERR, "20\n"); uart->irqaction.handler = imx_uart_interrupt; uart->irqaction.name = "imx_uart"; uart->irqaction.dev_id = port; if ( setup_irq(uart->irq, 0, &uart->irqaction) != 0 ) { dprintk(XENLOG_ERR, "Failed to allocated imx_uart IRQ %d\n", uart->irq); return; } #ifdef CONFIG_IMX8_ZEBU // Send autobaud character imx_write(uart, UTXD, 0x55); imx_write(uart, UTXD, 0x55); imx_write(uart, UTXD, 0x0A); #endif /* Enable interrupts */ dprintk(XENLOG_ERR, "%s\n", __func__); imx_write(uart, UCR1, UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_UARTEN); //imx_write(uart, UCR1, UCR1_TXMPTYEN | UCR1_UARTEN); } static void imx_uart_suspend(struct serial_port *port) { BUG(); } static void imx_uart_resume(struct serial_port *port) { BUG(); } static int imx_uart_tx_ready(struct serial_port *port) { struct imx_uart *uart = port->uart; return (imx_read(uart, USR2) & USR2_TXDC) ? 1 : 0; } static void imx_uart_putc(struct serial_port *port, char c) { struct imx_uart *uart = port->uart; imx_write(uart, UTXD, (uint32_t)(unsigned char)c); } static int imx_uart_getc(struct serial_port *port, char *pc) { struct imx_uart *uart = port->uart; if (!(imx_read(uart, USR2) & USR2_RDR)) return 0; *pc = imx_read(uart, URXD) & 0xff; return 1; } static int __init imx_uart_irq(struct serial_port *port) { struct imx_uart *uart = port->uart; return ((uart->irq > 0) ? uart->irq : -1); } static const struct vuart_info *imx_vuart_info(struct serial_port *port) { struct imx_uart *uart = port->uart; return &uart->vuart; } static void imx_start_tx(struct serial_port *port) { struct imx_uart *uart = port->uart; unsigned long temp; /* Clear any pending ORE flag before enabling interrupt */ temp = imx_read(uart, USR2); imx_write(uart, USR2, temp | USR2_ORE); temp = imx_read(uart, UCR4); temp |= UCR4_OREN; imx_write(uart, UCR4, temp); temp = imx_read(uart, UCR1); imx_write(uart, UCR1, temp | UCR1_TXMPTYEN); return; } static void imx_stop_tx(struct serial_port *port) { struct imx_uart *uart = port->uart; unsigned long temp; temp = imx_read(uart, UCR1); imx_write(uart, UCR1, temp & ~UCR1_TXMPTYEN); return; } static struct uart_driver __read_mostly imx_uart_driver = { .init_preirq = imx_uart_init_preirq, .init_postirq = imx_uart_init_postirq, .endboot = NULL, .suspend = imx_uart_suspend, .resume = imx_uart_resume, .tx_ready = imx_uart_tx_ready, .putc = imx_uart_putc, .getc = imx_uart_getc, .irq = imx_uart_irq, .start_tx = imx_start_tx, .stop_tx = imx_stop_tx, .vuart_info = imx_vuart_info, }; static int __init imx_uart_init(struct dt_device_node *dev, const void *data) { const char *config = data; struct imx_uart *uart; u32 clkspec; int res; u64 addr, size; dprintk(XENLOG_ERR, "xx %x\n", EARLY_UART_BASE_ADDRESS); if ( strcmp(config, "") ) printk("WARNING: UART configuration is not supported\n"); uart = &imx_com; #ifdef CONFIG_IMX8_ZEBU clkspec = 24000000; #else res = dt_property_read_u32(dev, "clock-frequency", &clkspec); if ( !res ) { printk("imx-uart: Unable to retrieve the clock frequency\n"); return -EINVAL; } #endif #define PARITY_NONE (0) uart->clock_hz = clkspec; uart->baud = 115200; uart->data_bits = 8; uart->parity = PARITY_NONE; uart->stop_bits = 1; res = dt_device_get_address(dev, 0, &addr, &size); if ( res ) { printk("imx-uart: Unable to retrieve the base" " address of the UART\n"); return res; } res = platform_get_irq(dev, 0); if ( res < 0 ) { printk("imx-uart: Unable to retrieve the IRQ\n"); return -EINVAL; } uart->irq = res; uart->regs = ioremap_nocache(addr, size); if ( !uart->regs ) { printk("imx-uart: Unable to map the UART memory\n"); return -ENOMEM; } uart->vuart.base_addr = addr; uart->vuart.size = size; uart->vuart.data_off = UTXD; /* tmp from uboot */ uart->vuart.status_off = UTS; uart->vuart.status = UTS_TXEMPTY; dprintk(XENLOG_ERR, "11\n"); /* Register with generic serial driver */ serial_register_uart(SERHND_DTUART, &imx_uart_driver, uart); dt_device_set_used_by(dev, DOMID_XEN); return 0; } static const struct dt_device_match imx_uart_dt_compat[] __initconst = { DT_MATCH_COMPATIBLE("fsl,imx21-uart"), {}, }; DT_DEVICE_START(imx_uart, "IMX UART", DEVICE_SERIAL) .dt_match = imx_uart_dt_compat, .init = imx_uart_init, DT_DEVICE_END Regards, Peng. > > Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > --- > I used the "earlycon=ec_imx6q,0x30890000" cmd arg and selected > CONFIG_SERIAL_IMX_EARLYCON in Linux for enabling vUART. > --- > --- > MAINTAINERS | 1 + > xen/drivers/char/Kconfig | 7 + > xen/drivers/char/Makefile | 1 + > xen/drivers/char/imx-uart.c | 299 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 308 insertions(+) > create mode 100644 xen/drivers/char/imx-uart.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 1bd22fd75f..bd4084fd20 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -249,6 +249,7 @@ F: xen/drivers/char/arm-uart.c > F: xen/drivers/char/cadence-uart.c > F: xen/drivers/char/exynos4210-uart.c > F: xen/drivers/char/imx-lpuart.c > +F: xen/drivers/char/imx-uart.c > F: xen/drivers/char/meson-uart.c > F: xen/drivers/char/mvebu-uart.c > F: xen/drivers/char/omap-uart.c > diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig index > e18ec3788c..f51a1f596a 100644 > --- a/xen/drivers/char/Kconfig > +++ b/xen/drivers/char/Kconfig > @@ -20,6 +20,13 @@ config HAS_IMX_LPUART > help > This selects the i.MX LPUART. If you have i.MX8QM based board, > say Y. > > +config HAS_IMX_UART > + bool "i.MX UART driver" > + default y > + depends on ARM_64 > + help > + This selects the i.MX UART. If you have i.MX8M* 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 > e7e374775d..147530a1ed 100644 > --- a/xen/drivers/char/Makefile > +++ b/xen/drivers/char/Makefile > @@ -10,6 +10,7 @@ obj-$(CONFIG_HAS_SCIF) += scif-uart.o > obj-$(CONFIG_HAS_EHCI) += ehci-dbgp.o > obj-$(CONFIG_XHCI) += xhci-dbc.o > obj-$(CONFIG_HAS_IMX_LPUART) += imx-lpuart.o > +obj-$(CONFIG_HAS_IMX_UART) += imx-uart.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-uart.c b/xen/drivers/char/imx-uart.c new file mode > 100644 index 0000000000..13bb189063 > --- /dev/null > +++ b/xen/drivers/char/imx-uart.c > @@ -0,0 +1,299 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * xen/drivers/char/imx-uart.c > + * > + * Driver for i.MX UART. > + * > + * Based on Linux's drivers/tty/serial/imx.c > + * > + * Copyright (C) 2024 EPAM Systems Inc. > + */ > + > +#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-uart.h> > +#include <asm/io.h> > + > +#define imx_uart_read(uart, off) readl((uart)->regs + (off)) > +#define imx_uart_write(uart, off, val) writel((val), (uart)->regs + (off)) > + > +static struct imx_uart { > + 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; > +} imx_com; > + > +static void imx_uart_interrupt(int irq, void *data) { > + struct serial_port *port = data; > + struct imx_uart *uart = port->uart; > + uint32_t usr1, usr2; > + > + usr1 = imx_uart_read(uart, USR1); > + usr2 = imx_uart_read(uart, USR2); > + > + if ( usr1 & (USR1_RRDY | USR1_AGTIM) ) > + { > + imx_uart_write(uart, USR1, USR1_AGTIM); > + serial_rx_interrupt(port); > + } > + > + if ( (usr1 & USR1_TRDY) || (usr2 & USR2_TXDC) ) > + serial_tx_interrupt(port); > +} > + > +static void imx_uart_clear_rx_errors(struct serial_port *port) { > + struct imx_uart *uart = port->uart; > + uint32_t usr1, usr2; > + > + usr1 = imx_uart_read(uart, USR1); > + usr2 = imx_uart_read(uart, USR2); > + > + if ( usr2 & USR2_BRCD ) > + imx_uart_write(uart, USR2, USR2_BRCD); > + else if ( usr1 & USR1_FRAMERR ) > + imx_uart_write(uart, USR1, USR1_FRAMERR); > + else if ( usr1 & USR1_PARITYERR ) > + imx_uart_write(uart, USR1, USR1_PARITYERR); > + > + if ( usr2 & USR2_ORE ) > + imx_uart_write(uart, USR2, USR2_ORE); } > + > +static void __init imx_uart_init_preirq(struct serial_port *port) { > + struct imx_uart *uart = port->uart; > + uint32_t reg; > + > + /* > + * Wait for the transmission to complete. This is needed for a smooth > + * transition when we come from early printk. > + */ > + while ( !(imx_uart_read(uart, USR2) & USR2_TXDC) ) > + cpu_relax(); > + > + /* Set receiver/transmitter trigger level */ > + reg = imx_uart_read(uart, UFCR); > + reg &= (UFCR_RFDIV | UFCR_DCEDTE); > + reg |= TXTL_DEFAULT << UFCR_TXTL_SHF | RXTL_DEFAULT; > + imx_uart_write(uart, UFCR, reg); > + > + /* Enable UART and disable interrupts/DMA */ > + reg = imx_uart_read(uart, UCR1); > + reg |= UCR1_UARTEN; > + reg &= ~(UCR1_TRDYEN | UCR1_TXMPTYEN | UCR1_RTSDEN | > UCR1_RRDYEN | > + UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN); > + imx_uart_write(uart, UCR1, reg); > + > + /* Enable receiver/transmitter and disable Aging Timer */ > + reg = imx_uart_read(uart, UCR2); > + reg |= UCR2_RXEN | UCR2_TXEN; > + reg &= ~UCR2_ATEN; > + imx_uart_write(uart, UCR2, reg); > + > + /* Disable interrupts */ > + reg = imx_uart_read(uart, UCR4); > + reg &= ~(UCR4_TCEN | UCR4_DREN); > + imx_uart_write(uart, UCR4, reg); > +} > + > +static void __init imx_uart_init_postirq(struct serial_port *port) { > + struct imx_uart *uart = port->uart; > + > + uart->irqaction.handler = imx_uart_interrupt; > + uart->irqaction.name = "imx_uart"; > + uart->irqaction.dev_id = port; > + > + if ( setup_irq(uart->irq, 0, &uart->irqaction) != 0 ) > + { > + dprintk(XENLOG_ERR, "Failed to allocate imx_uart IRQ %d\n", uart->irq); > + return; > + } > + > + /* Clear possible receiver errors */ > + imx_uart_clear_rx_errors(port); > + > + /* Enable interrupts */ > + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) | > + UCR1_RRDYEN | UCR1_TRDYEN); > + imx_uart_write(uart, UCR2, imx_uart_read(uart, UCR2) | UCR2_ATEN); > +} > + > +static void imx_uart_suspend(struct serial_port *port) { > + BUG(); > +} > + > +static void imx_uart_resume(struct serial_port *port) { > + BUG(); > +} > + > +static int imx_uart_tx_ready(struct serial_port *port) { > + struct imx_uart *uart = port->uart; > + uint32_t reg; > + > + reg = imx_uart_read(uart, IMX21_UTS); > + if ( reg & UTS_TXEMPTY ) > + return TX_FIFO_SIZE; > + if ( reg & UTS_TXFULL ) > + return 0; > + > + /* > + * If the FIFO is neither full nor empty then there is a space for > + * one char at least. > + */ > + return 1; > +} > + > +static void imx_uart_putc(struct serial_port *port, char c) { > + struct imx_uart *uart = port->uart; > + > + while ( imx_uart_read(uart, IMX21_UTS) & UTS_TXFULL ) > + cpu_relax(); > + > + imx_uart_write(uart, URTX0, c); > +} > + > +static int imx_uart_getc(struct serial_port *port, char *pc) { > + struct imx_uart *uart = port->uart; > + uint32_t data; > + > + if ( !(imx_uart_read(uart, USR2) & USR2_RDR) ) > + return 0; > + > + data = imx_uart_read(uart, URXD0); > + *pc = data & URXD_RX_DATA; > + > + if ( unlikely(data & URXD_ERR) ) > + imx_uart_clear_rx_errors(port); > + > + return 1; > +} > + > +static int __init imx_uart_irq(struct serial_port *port) { > + struct imx_uart *uart = port->uart; > + > + return ((uart->irq > 0) ? uart->irq : -1); } > + > +static const struct vuart_info *imx_uart_vuart_info(struct serial_port > +*port) { > + struct imx_uart *uart = port->uart; > + > + return &uart->vuart; > +} > + > +static void imx_uart_start_tx(struct serial_port *port) { > + struct imx_uart *uart = port->uart; > + > + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) | > +UCR1_TRDYEN); } > + > +static void imx_uart_stop_tx(struct serial_port *port) { > + struct imx_uart *uart = port->uart; > + > + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) & > +~UCR1_TRDYEN); } > + > +static struct uart_driver __read_mostly imx_uart_driver = { > + .init_preirq = imx_uart_init_preirq, > + .init_postirq = imx_uart_init_postirq, > + .endboot = NULL, > + .suspend = imx_uart_suspend, > + .resume = imx_uart_resume, > + .tx_ready = imx_uart_tx_ready, > + .putc = imx_uart_putc, > + .getc = imx_uart_getc, > + .irq = imx_uart_irq, > + .start_tx = imx_uart_start_tx, > + .stop_tx = imx_uart_stop_tx, > + .vuart_info = imx_uart_vuart_info, > +}; > + > +static int __init imx_uart_init(struct dt_device_node *dev, const void > +*data) { > + const char *config = data; > + struct imx_uart *uart; > + int res; > + paddr_t addr, size; > + > + if ( strcmp(config, "") ) > + printk("WARNING: UART configuration is not supported\n"); > + > + uart = &imx_com; > + > + uart->baud = 115200; > + uart->data_bits = 8; > + uart->parity = 0; > + uart->stop_bits = 1; > + > + res = dt_device_get_paddr(dev, 0, &addr, &size); > + if ( res ) > + { > + printk("imx-uart: Unable to retrieve the base address of the UART\n"); > + return res; > + } > + > + res = platform_get_irq(dev, 0); > + if ( res < 0 ) > + { > + printk("imx-uart: Unable to retrieve the IRQ\n"); > + return -EINVAL; > + } > + uart->irq = res; > + > + uart->regs = ioremap_nocache(addr, size); > + if ( !uart->regs ) > + { > + printk("imx-uart: Unable to map the UART memory\n"); > + return -ENOMEM; > + } > + > + uart->vuart.base_addr = addr; > + uart->vuart.size = size; > + uart->vuart.data_off = URTX0; > + uart->vuart.status_off = IMX21_UTS; > + uart->vuart.status = UTS_TXEMPTY; > + > + /* Register with generic serial driver */ > + serial_register_uart(SERHND_DTUART, &imx_uart_driver, uart); > + > + dt_device_set_used_by(dev, DOMID_XEN); > + > + return 0; > +} > + > +static const struct dt_device_match imx_uart_dt_compat[] __initconst = > +{ > + DT_MATCH_COMPATIBLE("fsl,imx6q-uart"), > + { /* sentinel */ }, > +}; > + > +DT_DEVICE_START(imx_uart, "i.MX UART", DEVICE_SERIAL) > + .dt_match = imx_uart_dt_compat, > + .init = imx_uart_init, > +DT_DEVICE_END > + > +/* > + * Local variables: > + * mode: C > + * c-file-style: "BSD" > + * c-basic-offset: 4 > + * indent-tabs-mode: nil > + * End: > + */ > -- > 2.34.1
On 04.04.24 09:54, Michal Orzel wrote: > Hi Oleksandr, Hello Michal sorry for the late response > > On 02/04/2024 14:05, Oleksandr Tyshchenko wrote: >> >> >> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> >> >> The i.MX UART Documentation: >> https://www.nxp.com/webapp/Download?colCode=IMX8MMRM >> Chapter 16.2 Universal Asynchronous Receiver/Transmitter (UART) >> >> Tested on i.MX 8M Mini only, but I guess, it should be > imperative mood ok > >> suitable for other i.MX8M* SoCs (those UART device tree nodes >> contain "fsl,imx6q-uart" compatible string). >> >> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> >> --- >> I used the "earlycon=ec_imx6q,0x30890000" cmd arg and >> selected CONFIG_SERIAL_IMX_EARLYCON in Linux for enabling vUART. >> --- >> --- >> MAINTAINERS | 1 + >> xen/drivers/char/Kconfig | 7 + >> xen/drivers/char/Makefile | 1 + >> xen/drivers/char/imx-uart.c | 299 ++++++++++++++++++++++++++++++++++++ >> 4 files changed, 308 insertions(+) >> create mode 100644 xen/drivers/char/imx-uart.c >> >> diff --git a/MAINTAINERS b/MAINTAINERS >> index 1bd22fd75f..bd4084fd20 100644 >> --- a/MAINTAINERS >> +++ b/MAINTAINERS >> @@ -249,6 +249,7 @@ F: xen/drivers/char/arm-uart.c >> F: xen/drivers/char/cadence-uart.c >> F: xen/drivers/char/exynos4210-uart.c >> F: xen/drivers/char/imx-lpuart.c >> +F: xen/drivers/char/imx-uart.c >> F: xen/drivers/char/meson-uart.c >> F: xen/drivers/char/mvebu-uart.c >> F: xen/drivers/char/omap-uart.c >> diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig >> index e18ec3788c..f51a1f596a 100644 >> --- a/xen/drivers/char/Kconfig >> +++ b/xen/drivers/char/Kconfig >> @@ -20,6 +20,13 @@ config HAS_IMX_LPUART >> help >> This selects the i.MX LPUART. If you have i.MX8QM based board, say Y. >> >> +config HAS_IMX_UART >> + bool "i.MX UART driver" >> + default y >> + depends on ARM_64 >> + help >> + This selects the i.MX UART. If you have i.MX8M* 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 e7e374775d..147530a1ed 100644 >> --- a/xen/drivers/char/Makefile >> +++ b/xen/drivers/char/Makefile >> @@ -10,6 +10,7 @@ obj-$(CONFIG_HAS_SCIF) += scif-uart.o >> obj-$(CONFIG_HAS_EHCI) += ehci-dbgp.o >> obj-$(CONFIG_XHCI) += xhci-dbc.o >> obj-$(CONFIG_HAS_IMX_LPUART) += imx-lpuart.o >> +obj-$(CONFIG_HAS_IMX_UART) += imx-uart.o >> obj-$(CONFIG_ARM) += arm-uart.o >> obj-y += serial.o >> obj-$(CONFIG_XEN_GUEST) += xen_pv_console.o >> diff --git a/xen/drivers/char/imx-uart.c b/xen/drivers/char/imx-uart.c >> new file mode 100644 >> index 0000000000..13bb189063 >> --- /dev/null >> +++ b/xen/drivers/char/imx-uart.c >> @@ -0,0 +1,299 @@ >> +/* SPDX-License-Identifier: GPL-2.0-or-later */ > Can it be GPL-2.0-only? Some companies are worried about v3. I guess, it can, will change > >> +/* >> + * xen/drivers/char/imx-uart.c >> + * >> + * Driver for i.MX UART. >> + * >> + * Based on Linux's drivers/tty/serial/imx.c >> + * >> + * Copyright (C) 2024 EPAM Systems Inc. >> + */ >> + >> +#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-uart.h> >> +#include <asm/io.h> >> + >> +#define imx_uart_read(uart, off) readl((uart)->regs + (off)) >> +#define imx_uart_write(uart, off, val) writel((val), (uart)->regs + (off)) >> + >> +static struct imx_uart { >> + uint32_t baud, clock_hz, data_bits, parity, stop_bits, fifo_size; > What's the use of these variables? AFAICT they are set but never used. right, this is a copy paste from other UART driver, will drop > >> + uint32_t irq; > unsigned int > >> + char __iomem *regs; >> + struct irqaction irqaction; >> + struct vuart_info vuart; >> +} imx_com; >> + >> +static void imx_uart_interrupt(int irq, void *data) >> +{ >> + struct serial_port *port = data; >> + struct imx_uart *uart = port->uart; >> + uint32_t usr1, usr2; >> + >> + usr1 = imx_uart_read(uart, USR1); >> + usr2 = imx_uart_read(uart, USR2); >> + >> + if ( usr1 & (USR1_RRDY | USR1_AGTIM) ) >> + { >> + imx_uart_write(uart, USR1, USR1_AGTIM); >> + serial_rx_interrupt(port); >> + } >> + >> + if ( (usr1 & USR1_TRDY) || (usr2 & USR2_TXDC) ) >> + serial_tx_interrupt(port); >> +} >> + >> +static void imx_uart_clear_rx_errors(struct serial_port *port) >> +{ >> + struct imx_uart *uart = port->uart; >> + uint32_t usr1, usr2; >> + >> + usr1 = imx_uart_read(uart, USR1); >> + usr2 = imx_uart_read(uart, USR2); >> + >> + if ( usr2 & USR2_BRCD ) >> + imx_uart_write(uart, USR2, USR2_BRCD); >> + else if ( usr1 & USR1_FRAMERR ) >> + imx_uart_write(uart, USR1, USR1_FRAMERR); >> + else if ( usr1 & USR1_PARITYERR ) >> + imx_uart_write(uart, USR1, USR1_PARITYERR); >> + >> + if ( usr2 & USR2_ORE ) >> + imx_uart_write(uart, USR2, USR2_ORE); >> +} >> + >> +static void __init imx_uart_init_preirq(struct serial_port *port) >> +{ >> + struct imx_uart *uart = port->uart; >> + uint32_t reg; >> + >> + /* >> + * Wait for the transmission to complete. This is needed for a smooth >> + * transition when we come from early printk. >> + */ >> + while ( !(imx_uart_read(uart, USR2) & USR2_TXDC) ) >> + cpu_relax(); >> + >> + /* Set receiver/transmitter trigger level */ >> + reg = imx_uart_read(uart, UFCR); >> + reg &= (UFCR_RFDIV | UFCR_DCEDTE); >> + reg |= TXTL_DEFAULT << UFCR_TXTL_SHF | RXTL_DEFAULT; > please surround TXTL_DEFAULT << UFCR_TXTL_SHF with parentheses will do > >> + imx_uart_write(uart, UFCR, reg); >> + >> + /* Enable UART and disable interrupts/DMA */ >> + reg = imx_uart_read(uart, UCR1); >> + reg |= UCR1_UARTEN; >> + reg &= ~(UCR1_TRDYEN | UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN | >> + UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN); >> + imx_uart_write(uart, UCR1, reg); >> + >> + /* Enable receiver/transmitter and disable Aging Timer */ >> + reg = imx_uart_read(uart, UCR2); >> + reg |= UCR2_RXEN | UCR2_TXEN; >> + reg &= ~UCR2_ATEN; >> + imx_uart_write(uart, UCR2, reg); >> + >> + /* Disable interrupts */ >> + reg = imx_uart_read(uart, UCR4); >> + reg &= ~(UCR4_TCEN | UCR4_DREN); >> + imx_uart_write(uart, UCR4, reg); >> +} >> + >> +static void __init imx_uart_init_postirq(struct serial_port *port) >> +{ >> + struct imx_uart *uart = port->uart; >> + >> + uart->irqaction.handler = imx_uart_interrupt; >> + uart->irqaction.name = "imx_uart"; >> + uart->irqaction.dev_id = port; >> + >> + if ( setup_irq(uart->irq, 0, &uart->irqaction) != 0 ) >> + { >> + dprintk(XENLOG_ERR, "Failed to allocate imx_uart IRQ %d\n", uart->irq); > Wrong format specifier for unsigned, use %u ok > Also, why dprintk? the same answer, copy paste from other UART driver, will change to printk > >> + return; >> + } >> + >> + /* Clear possible receiver errors */ >> + imx_uart_clear_rx_errors(port); >> + >> + /* Enable interrupts */ >> + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) | >> + UCR1_RRDYEN | UCR1_TRDYEN); >> + imx_uart_write(uart, UCR2, imx_uart_read(uart, UCR2) | UCR2_ATEN); >> +} >> + >> +static void imx_uart_suspend(struct serial_port *port) >> +{ >> + BUG(); >> +} > no need for this function > >> + >> +static void imx_uart_resume(struct serial_port *port) >> +{ >> + BUG(); >> +} > no need for this function will drop > >> + >> +static int imx_uart_tx_ready(struct serial_port *port) >> +{ >> + struct imx_uart *uart = port->uart; > can be const ok > >> + uint32_t reg; >> + >> + reg = imx_uart_read(uart, IMX21_UTS); >> + if ( reg & UTS_TXEMPTY ) >> + return TX_FIFO_SIZE; > empty line here please ok > >> + if ( reg & UTS_TXFULL ) >> + return 0; >> + >> + /* >> + * If the FIFO is neither full nor empty then there is a space for >> + * one char at least. >> + */ >> + return 1; >> +} >> + >> +static void imx_uart_putc(struct serial_port *port, char c) >> +{ >> + struct imx_uart *uart = port->uart; > can be const ok > >> + >> + while ( imx_uart_read(uart, IMX21_UTS) & UTS_TXFULL ) >> + cpu_relax(); > Looking at pl011, cdns, putc contains only a write to data register. This is because > ->putc always follows ->tx_ready which contains the check for how many chars can be written. > Therefore, AFAICT this should be dropped. really good point, driver does implement tx_ready cb, so I will drop the useless check. I think, this will improve things as we won't need to read the hw register every time we write a single character... > >> + >> + imx_uart_write(uart, URTX0, c); >> +} >> + >> +static int imx_uart_getc(struct serial_port *port, char *pc) >> +{ >> + struct imx_uart *uart = port->uart; > can be const ok > >> + uint32_t data; >> + >> + if ( !(imx_uart_read(uart, USR2) & USR2_RDR) ) >> + return 0; >> + >> + data = imx_uart_read(uart, URXD0); >> + *pc = data & URXD_RX_DATA; >> + >> + if ( unlikely(data & URXD_ERR) ) >> + imx_uart_clear_rx_errors(port); >> + >> + return 1; >> +} >> + >> +static int __init imx_uart_irq(struct serial_port *port) >> +{ >> + struct imx_uart *uart = port->uart; > can be const ok > >> + >> + return ((uart->irq > 0) ? uart->irq : -1); >> +} >> + >> +static const struct vuart_info *imx_uart_vuart_info(struct serial_port *port) >> +{ >> + struct imx_uart *uart = port->uart; > can be const ok > >> + >> + return &uart->vuart; >> +} >> + >> +static void imx_uart_start_tx(struct serial_port *port) >> +{ >> + struct imx_uart *uart = port->uart; >> + >> + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) | UCR1_TRDYEN); >> +} >> + >> +static void imx_uart_stop_tx(struct serial_port *port) >> +{ >> + struct imx_uart *uart = port->uart; >> + >> + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) & ~UCR1_TRDYEN); >> +} >> + >> +static struct uart_driver __read_mostly imx_uart_driver = { >> + .init_preirq = imx_uart_init_preirq, >> + .init_postirq = imx_uart_init_postirq, >> + .endboot = NULL, >> + .suspend = imx_uart_suspend, >> + .resume = imx_uart_resume, > no need to assign a value for these 3 members will drop > >> + .tx_ready = imx_uart_tx_ready, >> + .putc = imx_uart_putc, >> + .getc = imx_uart_getc, >> + .irq = imx_uart_irq, >> + .start_tx = imx_uart_start_tx, >> + .stop_tx = imx_uart_stop_tx, >> + .vuart_info = imx_uart_vuart_info, >> +}; >> + >> +static int __init imx_uart_init(struct dt_device_node *dev, const void *data) >> +{ >> + const char *config = data; >> + struct imx_uart *uart; >> + int res; >> + paddr_t addr, size; >> + >> + if ( strcmp(config, "") ) >> + printk("WARNING: UART configuration is not supported\n"); >> + >> + uart = &imx_com; >> + >> + uart->baud = 115200; >> + uart->data_bits = 8; >> + uart->parity = 0; >> + uart->stop_bits = 1; > They are set but never used you are right, will drop these fields entirely > >> + >> + res = dt_device_get_paddr(dev, 0, &addr, &size); >> + if ( res ) >> + { >> + printk("imx-uart: Unable to retrieve the base address of the UART\n"); >> + return res; >> + } >> + >> + res = platform_get_irq(dev, 0); >> + if ( res < 0 ) >> + { >> + printk("imx-uart: Unable to retrieve the IRQ\n"); >> + return -EINVAL; >> + } >> + uart->irq = res; >> + >> + uart->regs = ioremap_nocache(addr, size); >> + if ( !uart->regs ) >> + { >> + printk("imx-uart: Unable to map the UART memory\n"); >> + return -ENOMEM; >> + } >> + >> + uart->vuart.base_addr = addr; >> + uart->vuart.size = size; >> + uart->vuart.data_off = URTX0; >> + uart->vuart.status_off = IMX21_UTS; >> + uart->vuart.status = UTS_TXEMPTY; >> + >> + /* Register with generic serial driver */ >> + serial_register_uart(SERHND_DTUART, &imx_uart_driver, uart); >> + >> + dt_device_set_used_by(dev, DOMID_XEN); >> + >> + return 0; >> +} >> + >> +static const struct dt_device_match imx_uart_dt_compat[] __initconst = >> +{ >> + DT_MATCH_COMPATIBLE("fsl,imx6q-uart"), >> + { /* sentinel */ }, >> +}; >> + >> +DT_DEVICE_START(imx_uart, "i.MX UART", DEVICE_SERIAL) >> + .dt_match = imx_uart_dt_compat, >> + .init = imx_uart_init, >> +DT_DEVICE_END >> + >> +/* >> + * Local variables: >> + * mode: C >> + * c-file-style: "BSD" >> + * c-basic-offset: 4 >> + * indent-tabs-mode: nil >> + * End: >> + */ >> -- >> 2.34.1 >> > > ~Michal >
On 07.04.24 05:43, Peng Fan wrote: > Hi Oleksandr, Hello Peng > >> Subject: [PATCH 2/2] xen/arm: Add i.MX UART driver >> >> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> >> >> The i.MX UART Documentation: >> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww. >> nxp.com%2Fwebapp%2FDownload%3FcolCode%3DIMX8MMRM&data=05%7 >> C02%7Cpeng.fan%40nxp.com%7C6ada06c4133849667f3608dc530d5471%7 >> C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6384765639197564 >> 70%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz >> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=RmXgAMb7 >> wFZ7epZgYgHJo4LH35rzQhD05yTXSkttXbc%3D&reserved=0 >> Chapter 16.2 Universal Asynchronous Receiver/Transmitter (UART) >> >> Tested on i.MX 8M Mini only, but I guess, it should be suitable for other >> i.MX8M* SoCs (those UART device tree nodes contain "fsl,imx6q-uart" >> compatible string). > > Good to see people are interested in XEN on 8M. > I had an implementation back in 2015, you could take a look. Thanks. When I was googling for what was publicly available on Xen exactly for i.MX 8M Mini (before start writing this driver), I didn't find that implementation. Interesting to compare [snip]
diff --git a/MAINTAINERS b/MAINTAINERS index 1bd22fd75f..bd4084fd20 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -249,6 +249,7 @@ F: xen/drivers/char/arm-uart.c F: xen/drivers/char/cadence-uart.c F: xen/drivers/char/exynos4210-uart.c F: xen/drivers/char/imx-lpuart.c +F: xen/drivers/char/imx-uart.c F: xen/drivers/char/meson-uart.c F: xen/drivers/char/mvebu-uart.c F: xen/drivers/char/omap-uart.c diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig index e18ec3788c..f51a1f596a 100644 --- a/xen/drivers/char/Kconfig +++ b/xen/drivers/char/Kconfig @@ -20,6 +20,13 @@ config HAS_IMX_LPUART help This selects the i.MX LPUART. If you have i.MX8QM based board, say Y. +config HAS_IMX_UART + bool "i.MX UART driver" + default y + depends on ARM_64 + help + This selects the i.MX UART. If you have i.MX8M* 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 e7e374775d..147530a1ed 100644 --- a/xen/drivers/char/Makefile +++ b/xen/drivers/char/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_HAS_SCIF) += scif-uart.o obj-$(CONFIG_HAS_EHCI) += ehci-dbgp.o obj-$(CONFIG_XHCI) += xhci-dbc.o obj-$(CONFIG_HAS_IMX_LPUART) += imx-lpuart.o +obj-$(CONFIG_HAS_IMX_UART) += imx-uart.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-uart.c b/xen/drivers/char/imx-uart.c new file mode 100644 index 0000000000..13bb189063 --- /dev/null +++ b/xen/drivers/char/imx-uart.c @@ -0,0 +1,299 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * xen/drivers/char/imx-uart.c + * + * Driver for i.MX UART. + * + * Based on Linux's drivers/tty/serial/imx.c + * + * Copyright (C) 2024 EPAM Systems Inc. + */ + +#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-uart.h> +#include <asm/io.h> + +#define imx_uart_read(uart, off) readl((uart)->regs + (off)) +#define imx_uart_write(uart, off, val) writel((val), (uart)->regs + (off)) + +static struct imx_uart { + 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; +} imx_com; + +static void imx_uart_interrupt(int irq, void *data) +{ + struct serial_port *port = data; + struct imx_uart *uart = port->uart; + uint32_t usr1, usr2; + + usr1 = imx_uart_read(uart, USR1); + usr2 = imx_uart_read(uart, USR2); + + if ( usr1 & (USR1_RRDY | USR1_AGTIM) ) + { + imx_uart_write(uart, USR1, USR1_AGTIM); + serial_rx_interrupt(port); + } + + if ( (usr1 & USR1_TRDY) || (usr2 & USR2_TXDC) ) + serial_tx_interrupt(port); +} + +static void imx_uart_clear_rx_errors(struct serial_port *port) +{ + struct imx_uart *uart = port->uart; + uint32_t usr1, usr2; + + usr1 = imx_uart_read(uart, USR1); + usr2 = imx_uart_read(uart, USR2); + + if ( usr2 & USR2_BRCD ) + imx_uart_write(uart, USR2, USR2_BRCD); + else if ( usr1 & USR1_FRAMERR ) + imx_uart_write(uart, USR1, USR1_FRAMERR); + else if ( usr1 & USR1_PARITYERR ) + imx_uart_write(uart, USR1, USR1_PARITYERR); + + if ( usr2 & USR2_ORE ) + imx_uart_write(uart, USR2, USR2_ORE); +} + +static void __init imx_uart_init_preirq(struct serial_port *port) +{ + struct imx_uart *uart = port->uart; + uint32_t reg; + + /* + * Wait for the transmission to complete. This is needed for a smooth + * transition when we come from early printk. + */ + while ( !(imx_uart_read(uart, USR2) & USR2_TXDC) ) + cpu_relax(); + + /* Set receiver/transmitter trigger level */ + reg = imx_uart_read(uart, UFCR); + reg &= (UFCR_RFDIV | UFCR_DCEDTE); + reg |= TXTL_DEFAULT << UFCR_TXTL_SHF | RXTL_DEFAULT; + imx_uart_write(uart, UFCR, reg); + + /* Enable UART and disable interrupts/DMA */ + reg = imx_uart_read(uart, UCR1); + reg |= UCR1_UARTEN; + reg &= ~(UCR1_TRDYEN | UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN | + UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN); + imx_uart_write(uart, UCR1, reg); + + /* Enable receiver/transmitter and disable Aging Timer */ + reg = imx_uart_read(uart, UCR2); + reg |= UCR2_RXEN | UCR2_TXEN; + reg &= ~UCR2_ATEN; + imx_uart_write(uart, UCR2, reg); + + /* Disable interrupts */ + reg = imx_uart_read(uart, UCR4); + reg &= ~(UCR4_TCEN | UCR4_DREN); + imx_uart_write(uart, UCR4, reg); +} + +static void __init imx_uart_init_postirq(struct serial_port *port) +{ + struct imx_uart *uart = port->uart; + + uart->irqaction.handler = imx_uart_interrupt; + uart->irqaction.name = "imx_uart"; + uart->irqaction.dev_id = port; + + if ( setup_irq(uart->irq, 0, &uart->irqaction) != 0 ) + { + dprintk(XENLOG_ERR, "Failed to allocate imx_uart IRQ %d\n", uart->irq); + return; + } + + /* Clear possible receiver errors */ + imx_uart_clear_rx_errors(port); + + /* Enable interrupts */ + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) | + UCR1_RRDYEN | UCR1_TRDYEN); + imx_uart_write(uart, UCR2, imx_uart_read(uart, UCR2) | UCR2_ATEN); +} + +static void imx_uart_suspend(struct serial_port *port) +{ + BUG(); +} + +static void imx_uart_resume(struct serial_port *port) +{ + BUG(); +} + +static int imx_uart_tx_ready(struct serial_port *port) +{ + struct imx_uart *uart = port->uart; + uint32_t reg; + + reg = imx_uart_read(uart, IMX21_UTS); + if ( reg & UTS_TXEMPTY ) + return TX_FIFO_SIZE; + if ( reg & UTS_TXFULL ) + return 0; + + /* + * If the FIFO is neither full nor empty then there is a space for + * one char at least. + */ + return 1; +} + +static void imx_uart_putc(struct serial_port *port, char c) +{ + struct imx_uart *uart = port->uart; + + while ( imx_uart_read(uart, IMX21_UTS) & UTS_TXFULL ) + cpu_relax(); + + imx_uart_write(uart, URTX0, c); +} + +static int imx_uart_getc(struct serial_port *port, char *pc) +{ + struct imx_uart *uart = port->uart; + uint32_t data; + + if ( !(imx_uart_read(uart, USR2) & USR2_RDR) ) + return 0; + + data = imx_uart_read(uart, URXD0); + *pc = data & URXD_RX_DATA; + + if ( unlikely(data & URXD_ERR) ) + imx_uart_clear_rx_errors(port); + + return 1; +} + +static int __init imx_uart_irq(struct serial_port *port) +{ + struct imx_uart *uart = port->uart; + + return ((uart->irq > 0) ? uart->irq : -1); +} + +static const struct vuart_info *imx_uart_vuart_info(struct serial_port *port) +{ + struct imx_uart *uart = port->uart; + + return &uart->vuart; +} + +static void imx_uart_start_tx(struct serial_port *port) +{ + struct imx_uart *uart = port->uart; + + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) | UCR1_TRDYEN); +} + +static void imx_uart_stop_tx(struct serial_port *port) +{ + struct imx_uart *uart = port->uart; + + imx_uart_write(uart, UCR1, imx_uart_read(uart, UCR1) & ~UCR1_TRDYEN); +} + +static struct uart_driver __read_mostly imx_uart_driver = { + .init_preirq = imx_uart_init_preirq, + .init_postirq = imx_uart_init_postirq, + .endboot = NULL, + .suspend = imx_uart_suspend, + .resume = imx_uart_resume, + .tx_ready = imx_uart_tx_ready, + .putc = imx_uart_putc, + .getc = imx_uart_getc, + .irq = imx_uart_irq, + .start_tx = imx_uart_start_tx, + .stop_tx = imx_uart_stop_tx, + .vuart_info = imx_uart_vuart_info, +}; + +static int __init imx_uart_init(struct dt_device_node *dev, const void *data) +{ + const char *config = data; + struct imx_uart *uart; + int res; + paddr_t addr, size; + + if ( strcmp(config, "") ) + printk("WARNING: UART configuration is not supported\n"); + + uart = &imx_com; + + uart->baud = 115200; + uart->data_bits = 8; + uart->parity = 0; + uart->stop_bits = 1; + + res = dt_device_get_paddr(dev, 0, &addr, &size); + if ( res ) + { + printk("imx-uart: Unable to retrieve the base address of the UART\n"); + return res; + } + + res = platform_get_irq(dev, 0); + if ( res < 0 ) + { + printk("imx-uart: Unable to retrieve the IRQ\n"); + return -EINVAL; + } + uart->irq = res; + + uart->regs = ioremap_nocache(addr, size); + if ( !uart->regs ) + { + printk("imx-uart: Unable to map the UART memory\n"); + return -ENOMEM; + } + + uart->vuart.base_addr = addr; + uart->vuart.size = size; + uart->vuart.data_off = URTX0; + uart->vuart.status_off = IMX21_UTS; + uart->vuart.status = UTS_TXEMPTY; + + /* Register with generic serial driver */ + serial_register_uart(SERHND_DTUART, &imx_uart_driver, uart); + + dt_device_set_used_by(dev, DOMID_XEN); + + return 0; +} + +static const struct dt_device_match imx_uart_dt_compat[] __initconst = +{ + DT_MATCH_COMPATIBLE("fsl,imx6q-uart"), + { /* sentinel */ }, +}; + +DT_DEVICE_START(imx_uart, "i.MX UART", DEVICE_SERIAL) + .dt_match = imx_uart_dt_compat, + .init = imx_uart_init, +DT_DEVICE_END + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */