--- /dev/null
+/*
+ * xen/drivers/char/cadence-uart.c
+ *
+ * Driver for Cadence UART in Xilinx ZynqMP.
+ *
+ * Written by Edgar E. Iglesias <edgar.iglesias@gmail.com>
+ * 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 struct dt_device_match cuart_dt_match[] __initconst =
+{
+ DT_MATCH_COMPATIBLE("cdns,uart-r1p8"),
+ { /* sentinel */ },
+};
+
+DT_DEVICE_START(cuart, "Cadence UART", DEVICE_SERIAL)
+ .dt_match = cuart_dt_match,
+ .init = cuart_init,
+DT_DEVICE_END
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--- /dev/null
+/*
+ * xen/include/asm-arm/cadence-uart.h
+ *
+ * Written by Edgar E. Iglesias <edgar.iglesias@xilinx.com>
+ * 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:
+ */
projects / people / gdunlap / xen.git / commitdiff