[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v1 1/2] xen/arm: Add Cadence UART driver
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xxxxxxxxxx> --- config/arm64.mk | 1 + xen/drivers/char/Makefile | 1 + xen/drivers/char/cadence-uart.c | 222 +++++++++++++++++++++++++++++++++++++ xen/include/asm-arm/cadence-uart.h | 55 +++++++++ 4 files changed, 279 insertions(+) create mode 100644 xen/drivers/char/cadence-uart.c create mode 100644 xen/include/asm-arm/cadence-uart.h diff --git a/config/arm64.mk b/config/arm64.mk index 6eafda2..df6ad0a 100644 --- a/config/arm64.mk +++ b/config/arm64.mk @@ -7,6 +7,7 @@ CONFIG_XEN_INSTALL_SUFFIX := CFLAGS += #-marm -march= -mcpu= etc HAS_PL011 := y +HAS_CADENCE_UART := y HAS_NS16550 := y # Use only if calling $(LD) directly. diff --git a/xen/drivers/char/Makefile b/xen/drivers/char/Makefile index 9e94195..47fc3f9 100644 --- a/xen/drivers/char/Makefile +++ b/xen/drivers/char/Makefile @@ -1,5 +1,6 @@ obj-y += console.o obj-$(HAS_NS16550) += ns16550.o +obj-$(HAS_CADENCE_UART) += cadence-uart.o obj-$(HAS_PL011) += pl011.o obj-$(HAS_EXYNOS4210) += exynos4210-uart.o obj-$(HAS_OMAP) += omap-uart.o diff --git a/xen/drivers/char/cadence-uart.c b/xen/drivers/char/cadence-uart.c new file mode 100644 index 0000000..583bf21 --- /dev/null +++ b/xen/drivers/char/cadence-uart.c @@ -0,0 +1,222 @@ +/* + * xen/drivers/char/cadence-uart.c + * + * Driver for Cadence UART in Xilinx ZynqMP. + * + * Written by Edgar E. Iglesias <edgar.iglesias@xxxxxxxxx> + * Copyright (c) 2015 Xilinx Inc. + * + * 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/config.h> +#include <xen/console.h> +#include <xen/serial.h> +#include <xen/init.h> +#include <xen/irq.h> +#include <xen/device_tree.h> +#include <xen/errno.h> +#include <asm/device.h> +#include <xen/mm.h> +#include <xen/vmap.h> +#include <asm/cadence-uart.h> +#include <asm/io.h> + +static struct cuart { + unsigned int irq; + void __iomem *regs; + /* UART with IRQ line: interrupt-driven I/O. */ + struct irqaction irqaction; + struct vuart_info vuart; +} cuart_com = {0}; + +#define cuart_read(uart, off) readl((uart)->regs + (off)) +#define cuart_write(uart, off,val) writel((val), (uart)->regs + (off)) + +static void cuart_interrupt(int irq, void *data, struct cpu_user_regs *regs) +{ + struct serial_port *port = data; + struct cuart *uart = port->uart; + unsigned int status; + + do { + status = cuart_read(uart, R_UART_SR); + /* ACK. */ + if (status & UART_SR_INTR_RTRIG) { + serial_rx_interrupt(port, regs); + cuart_write(uart, R_UART_CISR, UART_SR_INTR_RTRIG); + } + } while (status & UART_SR_INTR_RTRIG); +} + +static void __init cuart_init_preirq(struct serial_port *port) +{ + struct cuart *uart = port->uart; + + cuart_write(uart, R_UART_MR, UART_MR_NO_PARITY); + /* Enable and Reset both the RX and TX paths. */ + cuart_write(uart, R_UART_CR, UART_CR_RX_RST | UART_CR_TX_RST | + UART_CR_RX_ENABLE | UART_CR_TX_ENABLE); +} + +static void __init cuart_init_postirq(struct serial_port *port) +{ + struct cuart *uart = port->uart; + int rc; + + if ( uart->irq > 0 ) { + uart->irqaction.handler = cuart_interrupt; + uart->irqaction.name = "cadence-uart"; + uart->irqaction.dev_id = port; + if ( (rc = setup_irq(uart->irq, 0, &uart->irqaction)) != 0 ) + printk("ERROR: Failed to allocate cadence-uart IRQ %d\n", uart->irq); + } + + /* Clear pending error interrupts */ + cuart_write(uart, R_UART_RTRIG, 1); + cuart_write(uart, R_UART_CISR, ~0); + + /* Unmask interrupts */ + cuart_write(uart, R_UART_IDR, ~0); + cuart_write(uart, R_UART_IER, UART_SR_INTR_RTRIG); +} + +static void cuart_suspend(struct serial_port *port) +{ + BUG(); +} + +static void cuart_resume(struct serial_port *port) +{ + BUG(); +} + +static int cuart_tx_ready(struct serial_port *port) +{ + struct cuart *uart = port->uart; + unsigned int status = cuart_read(uart, R_UART_SR); + + return !(status & UART_SR_INTR_TFUL); +} + +static void cuart_putc(struct serial_port *port, char c) +{ + struct cuart *uart = port->uart; + + cuart_write(uart, R_UART_TX, (uint32_t)(unsigned char)c); +} + +static int cuart_getc(struct serial_port *port, char *pc) +{ + struct cuart *uart = port->uart; + + if (cuart_read(uart, R_UART_SR) & UART_SR_INTR_REMPTY) + return 0; + + *pc = cuart_read(uart, R_UART_RX) & 0xff; + return 1; +} + +static int __init cuart_irq(struct serial_port *port) +{ + struct cuart *uart = port->uart; + + return ((uart->irq > 0) ? uart->irq : -1); +} + +static const struct vuart_info *cuart_vuart(struct serial_port *port) +{ + struct cuart *uart = port->uart; + + return &uart->vuart; +} + +static struct uart_driver __read_mostly cuart_driver = { + .init_preirq = cuart_init_preirq, + .init_postirq = cuart_init_postirq, + .endboot = NULL, + .suspend = cuart_suspend, + .resume = cuart_resume, + .tx_ready = cuart_tx_ready, + .putc = cuart_putc, + .getc = cuart_getc, + .irq = cuart_irq, + .vuart_info = cuart_vuart, +}; + +static int __init cuart_init(struct dt_device_node *dev, const void *data) +{ + const char *config = data; + struct cuart *uart; + int res; + u64 addr, size; + + if ( strcmp(config, "") ) + printk("WARNING: UART configuration is not supported\n"); + + uart = &cuart_com; + + res = dt_device_get_address(dev, 0, &addr, &size); + if ( res ) + { + printk("cadence: Unable to retrieve the base" + " address of the UART\n"); + return res; + } + + res = platform_get_irq(dev, 0); + if ( res < 0 ) + { + printk("cadence: Unable to retrieve the IRQ\n"); + return -EINVAL; + } + uart->irq = res; + + uart->regs = ioremap_nocache(addr, size); + if ( !uart->regs ) + { + printk("cadence: Unable to map the UART memory\n"); + return -ENOMEM; + } + + uart->vuart.base_addr = addr; + uart->vuart.size = size; + uart->vuart.data_off = R_UART_RX; + uart->vuart.status_off = R_UART_SR; + uart->vuart.status = UART_SR_INTR_TEMPTY; + + /* Register with generic serial driver. */ + serial_register_uart(SERHND_DTUART, &cuart_driver, uart); + + dt_device_set_used_by(dev, DOMID_XEN); + + return 0; +} + +static const char * const cuart_dt_compat[] __initconst = +{ + "cdns,uart-r1p8", + NULL +}; + +DT_DEVICE_START(cuart, "Cadence UART", DEVICE_SERIAL) + .compatible = cuart_dt_compat, + .init = cuart_init, +DT_DEVICE_END + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/include/asm-arm/cadence-uart.h b/xen/include/asm-arm/cadence-uart.h new file mode 100644 index 0000000..48680ee --- /dev/null +++ b/xen/include/asm-arm/cadence-uart.h @@ -0,0 +1,55 @@ +/* + * xen/include/asm-arm/cadence-uart.h + * + * Written by Edgar E. Iglesias <edgar.iglesias@xxxxxxxxxx> + * Copyright (C) 2015 Xilinx Inc. + * + * 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_CADENCE_UART_H__ +#define __ASM_ARM_CADENCE_UART_H__ + +#define R_UART_CR 0x00 +#define UART_CR_RX_RST 0x01 +#define UART_CR_TX_RST 0x02 +#define UART_CR_RX_ENABLE 0x04 +#define UART_CR_RX_DISABLE 0x08 +#define UART_CR_TX_ENABLE 0x10 +#define UART_CR_TX_DISABLE 0x20 + +#define R_UART_MR 0x04 +#define UART_MR_NO_PARITY 0x20 + +#define R_UART_IER 0x08 +#define R_UART_IDR 0x0C +#define R_UART_IMR 0x10 +#define R_UART_CISR 0x14 +#define R_UART_RTRIG 0x20 +#define R_UART_SR 0x2C +#define UART_SR_INTR_RTRIG 0x01 +#define UART_SR_INTR_REMPTY 0x02 +#define UART_SR_INTR_TEMPTY 0x08 +#define UART_SR_INTR_TFUL 0x10 + +#define R_UART_TX 0x30 +#define R_UART_RX 0x30 + +#endif /* __ASM_ARM_CADENCE_UART_H */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ -- 1.9.1 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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