Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 486 insertions, 0 deletions

diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
new file mode 100644
index 0000000000..5fab4c9788
--- /dev/null
+++ b/drivers/tty/serial/altera_jtaguart.c
@@ -0,0 +1,486 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * altera_jtaguart.c -- Altera JTAG UART driver
+ *
+ * Based on mcf.c -- Freescale ColdFire UART driver
+ *
+ * (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com>
+ * (C) Copyright 2008, Thomas Chou <thomas@wytron.com.tw>
+ * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/of.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/altera_jtaguart.h>
+
+#define DRV_NAME "altera_jtaguart"
+
+/*
+ * Altera JTAG UART register definitions according to the Altera JTAG UART
+ * datasheet: https://www.altera.com/literature/hb/nios2/n2cpu_nii51009.pdf
+ */
+
+#define ALTERA_JTAGUART_SIZE			8
+
+#define ALTERA_JTAGUART_DATA_REG		0
+
+#define ALTERA_JTAGUART_DATA_DATA_MSK		0x000000FF
+#define ALTERA_JTAGUART_DATA_RVALID_MSK		0x00008000
+#define ALTERA_JTAGUART_DATA_RAVAIL_MSK		0xFFFF0000
+#define ALTERA_JTAGUART_DATA_RAVAIL_OFF		16
+
+#define ALTERA_JTAGUART_CONTROL_REG		4
+
+#define ALTERA_JTAGUART_CONTROL_RE_MSK		0x00000001
+#define ALTERA_JTAGUART_CONTROL_WE_MSK		0x00000002
+#define ALTERA_JTAGUART_CONTROL_RI_MSK		0x00000100
+#define ALTERA_JTAGUART_CONTROL_RI_OFF		8
+#define ALTERA_JTAGUART_CONTROL_WI_MSK		0x00000200
+#define ALTERA_JTAGUART_CONTROL_AC_MSK		0x00000400
+#define ALTERA_JTAGUART_CONTROL_WSPACE_MSK	0xFFFF0000
+
+static unsigned int altera_jtaguart_tx_space(struct uart_port *port, u32 *ctlp)
+{
+	u32 ctl = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG);
+
+	if (ctlp)
+		*ctlp = ctl;
+
+	return FIELD_GET(ALTERA_JTAGUART_CONTROL_WSPACE_MSK, ctl);
+}
+
+static unsigned int altera_jtaguart_tx_empty(struct uart_port *port)
+{
+	return altera_jtaguart_tx_space(port, NULL) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int altera_jtaguart_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+static void altera_jtaguart_set_mctrl(struct uart_port *port, unsigned int sigs)
+{
+}
+
+static void altera_jtaguart_start_tx(struct uart_port *port)
+{
+	port->read_status_mask |= ALTERA_JTAGUART_CONTROL_WE_MSK;
+	writel(port->read_status_mask,
+			port->membase + ALTERA_JTAGUART_CONTROL_REG);
+}
+
+static void altera_jtaguart_stop_tx(struct uart_port *port)
+{
+	port->read_status_mask &= ~ALTERA_JTAGUART_CONTROL_WE_MSK;
+	writel(port->read_status_mask,
+			port->membase + ALTERA_JTAGUART_CONTROL_REG);
+}
+
+static void altera_jtaguart_stop_rx(struct uart_port *port)
+{
+	port->read_status_mask &= ~ALTERA_JTAGUART_CONTROL_RE_MSK;
+	writel(port->read_status_mask,
+			port->membase + ALTERA_JTAGUART_CONTROL_REG);
+}
+
+static void altera_jtaguart_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static void altera_jtaguart_set_termios(struct uart_port *port,
+				        struct ktermios *termios,
+				        const struct ktermios *old)
+{
+	/* Just copy the old termios settings back */
+	if (old)
+		tty_termios_copy_hw(termios, old);
+}
+
+static void altera_jtaguart_rx_chars(struct uart_port *port)
+{
+	u32 status;
+	u8 ch;
+
+	while ((status = readl(port->membase + ALTERA_JTAGUART_DATA_REG)) &
+	       ALTERA_JTAGUART_DATA_RVALID_MSK) {
+		ch = status & ALTERA_JTAGUART_DATA_DATA_MSK;
+		port->icount.rx++;
+
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+		uart_insert_char(port, 0, 0, ch, TTY_NORMAL);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void altera_jtaguart_tx_chars(struct uart_port *port)
+{
+	unsigned int count;
+	u8 ch;
+
+	count = altera_jtaguart_tx_space(port, NULL);
+
+	uart_port_tx_limited(port, ch, count,
+		true,
+		writel(ch, port->membase + ALTERA_JTAGUART_DATA_REG),
+		({}));
+}
+
+static irqreturn_t altera_jtaguart_interrupt(int irq, void *data)
+{
+	struct uart_port *port = data;
+	unsigned int isr;
+
+	isr = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) >>
+	       ALTERA_JTAGUART_CONTROL_RI_OFF) & port->read_status_mask;
+
+	spin_lock(&port->lock);
+
+	if (isr & ALTERA_JTAGUART_CONTROL_RE_MSK)
+		altera_jtaguart_rx_chars(port);
+	if (isr & ALTERA_JTAGUART_CONTROL_WE_MSK)
+		altera_jtaguart_tx_chars(port);
+
+	spin_unlock(&port->lock);
+
+	return IRQ_RETVAL(isr);
+}
+
+static void altera_jtaguart_config_port(struct uart_port *port, int flags)
+{
+	port->type = PORT_ALTERA_JTAGUART;
+
+	/* Clear mask, so no surprise interrupts. */
+	writel(0, port->membase + ALTERA_JTAGUART_CONTROL_REG);
+}
+
+static int altera_jtaguart_startup(struct uart_port *port)
+{
+	unsigned long flags;
+	int ret;
+
+	ret = request_irq(port->irq, altera_jtaguart_interrupt, 0,
+			DRV_NAME, port);
+	if (ret) {
+		pr_err(DRV_NAME ": unable to attach Altera JTAG UART %d "
+		       "interrupt vector=%d\n", port->line, port->irq);
+		return ret;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Enable RX interrupts now */
+	port->read_status_mask = ALTERA_JTAGUART_CONTROL_RE_MSK;
+	writel(port->read_status_mask,
+			port->membase + ALTERA_JTAGUART_CONTROL_REG);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+static void altera_jtaguart_shutdown(struct uart_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Disable all interrupts now */
+	port->read_status_mask = 0;
+	writel(port->read_status_mask,
+			port->membase + ALTERA_JTAGUART_CONTROL_REG);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	free_irq(port->irq, port);
+}
+
+static const char *altera_jtaguart_type(struct uart_port *port)
+{
+	return (port->type == PORT_ALTERA_JTAGUART) ? "Altera JTAG UART" : NULL;
+}
+
+static int altera_jtaguart_request_port(struct uart_port *port)
+{
+	/* UARTs always present */
+	return 0;
+}
+
+static void altera_jtaguart_release_port(struct uart_port *port)
+{
+	/* Nothing to release... */
+}
+
+static int altera_jtaguart_verify_port(struct uart_port *port,
+				       struct serial_struct *ser)
+{
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_ALTERA_JTAGUART)
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ *	Define the basic serial functions we support.
+ */
+static const struct uart_ops altera_jtaguart_ops = {
+	.tx_empty	= altera_jtaguart_tx_empty,
+	.get_mctrl	= altera_jtaguart_get_mctrl,
+	.set_mctrl	= altera_jtaguart_set_mctrl,
+	.start_tx	= altera_jtaguart_start_tx,
+	.stop_tx	= altera_jtaguart_stop_tx,
+	.stop_rx	= altera_jtaguart_stop_rx,
+	.break_ctl	= altera_jtaguart_break_ctl,
+	.startup	= altera_jtaguart_startup,
+	.shutdown	= altera_jtaguart_shutdown,
+	.set_termios	= altera_jtaguart_set_termios,
+	.type		= altera_jtaguart_type,
+	.request_port	= altera_jtaguart_request_port,
+	.release_port	= altera_jtaguart_release_port,
+	.config_port	= altera_jtaguart_config_port,
+	.verify_port	= altera_jtaguart_verify_port,
+};
+
+#define ALTERA_JTAGUART_MAXPORTS 1
+static struct uart_port altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS];
+
+#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE)
+
+#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
+static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c)
+{
+	unsigned long flags;
+	u32 status;
+
+	spin_lock_irqsave(&port->lock, flags);
+	while (!altera_jtaguart_tx_space(port, &status)) {
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
+			return;	/* no connection activity */
+		}
+
+		cpu_relax();
+		spin_lock_irqsave(&port->lock, flags);
+	}
+	writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+#else
+static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	while (!altera_jtaguart_tx_space(port, NULL)) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		cpu_relax();
+		spin_lock_irqsave(&port->lock, flags);
+	}
+	writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+#endif
+
+static void altera_jtaguart_console_write(struct console *co, const char *s,
+					  unsigned int count)
+{
+	struct uart_port *port = &altera_jtaguart_ports[co->index];
+
+	uart_console_write(port, s, count, altera_jtaguart_console_putc);
+}
+
+static int __init altera_jtaguart_console_setup(struct console *co,
+						char *options)
+{
+	struct uart_port *port;
+
+	if (co->index < 0 || co->index >= ALTERA_JTAGUART_MAXPORTS)
+		return -EINVAL;
+	port = &altera_jtaguart_ports[co->index];
+	if (port->membase == NULL)
+		return -ENODEV;
+	return 0;
+}
+
+static struct uart_driver altera_jtaguart_driver;
+
+static struct console altera_jtaguart_console = {
+	.name	= "ttyJ",
+	.write	= altera_jtaguart_console_write,
+	.device	= uart_console_device,
+	.setup	= altera_jtaguart_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+	.data	= &altera_jtaguart_driver,
+};
+
+static int __init altera_jtaguart_console_init(void)
+{
+	register_console(&altera_jtaguart_console);
+	return 0;
+}
+
+console_initcall(altera_jtaguart_console_init);
+
+#define	ALTERA_JTAGUART_CONSOLE	(&altera_jtaguart_console)
+
+static void altera_jtaguart_earlycon_write(struct console *co, const char *s,
+					   unsigned int count)
+{
+	struct earlycon_device *dev = co->data;
+
+	uart_console_write(&dev->port, s, count, altera_jtaguart_console_putc);
+}
+
+static int __init altera_jtaguart_earlycon_setup(struct earlycon_device *dev,
+						 const char *options)
+{
+	if (!dev->port.membase)
+		return -ENODEV;
+
+	dev->con->write = altera_jtaguart_earlycon_write;
+	return 0;
+}
+
+OF_EARLYCON_DECLARE(juart, "altr,juart-1.0", altera_jtaguart_earlycon_setup);
+
+#else
+
+#define	ALTERA_JTAGUART_CONSOLE	NULL
+
+#endif /* CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE */
+
+static struct uart_driver altera_jtaguart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "altera_jtaguart",
+	.dev_name	= "ttyJ",
+	.major		= ALTERA_JTAGUART_MAJOR,
+	.minor		= ALTERA_JTAGUART_MINOR,
+	.nr		= ALTERA_JTAGUART_MAXPORTS,
+	.cons		= ALTERA_JTAGUART_CONSOLE,
+};
+
+static int altera_jtaguart_probe(struct platform_device *pdev)
+{
+	struct altera_jtaguart_platform_uart *platp =
+			dev_get_platdata(&pdev->dev);
+	struct uart_port *port;
+	struct resource *res_mem;
+	int i = pdev->id;
+	int irq;
+
+	/* -1 emphasizes that the platform must have one port, no .N suffix */
+	if (i == -1)
+		i = 0;
+
+	if (i >= ALTERA_JTAGUART_MAXPORTS)
+		return -EINVAL;
+
+	port = &altera_jtaguart_ports[i];
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res_mem)
+		port->mapbase = res_mem->start;
+	else if (platp)
+		port->mapbase = platp->mapbase;
+	else
+		return -ENODEV;
+
+	irq = platform_get_irq_optional(pdev, 0);
+	if (irq < 0 && irq != -ENXIO)
+		return irq;
+	if (irq > 0)
+		port->irq = irq;
+	else if (platp)
+		port->irq = platp->irq;
+	else
+		return -ENODEV;
+
+	port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE);
+	if (!port->membase)
+		return -ENOMEM;
+
+	port->line = i;
+	port->type = PORT_ALTERA_JTAGUART;
+	port->iotype = SERIAL_IO_MEM;
+	port->ops = &altera_jtaguart_ops;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->dev = &pdev->dev;
+
+	uart_add_one_port(&altera_jtaguart_driver, port);
+
+	return 0;
+}
+
+static int altera_jtaguart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port;
+	int i = pdev->id;
+
+	if (i == -1)
+		i = 0;
+
+	port = &altera_jtaguart_ports[i];
+	uart_remove_one_port(&altera_jtaguart_driver, port);
+	iounmap(port->membase);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id altera_jtaguart_match[] = {
+	{ .compatible = "ALTR,juart-1.0", },
+	{ .compatible = "altr,juart-1.0", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, altera_jtaguart_match);
+#endif /* CONFIG_OF */
+
+static struct platform_driver altera_jtaguart_platform_driver = {
+	.probe	= altera_jtaguart_probe,
+	.remove	= altera_jtaguart_remove,
+	.driver	= {
+		.name		= DRV_NAME,
+		.of_match_table	= of_match_ptr(altera_jtaguart_match),
+	},
+};
+
+static int __init altera_jtaguart_init(void)
+{
+	int rc;
+
+	rc = uart_register_driver(&altera_jtaguart_driver);
+	if (rc)
+		return rc;
+	rc = platform_driver_register(&altera_jtaguart_platform_driver);
+	if (rc)
+		uart_unregister_driver(&altera_jtaguart_driver);
+	return rc;
+}
+
+static void __exit altera_jtaguart_exit(void)
+{
+	platform_driver_unregister(&altera_jtaguart_platform_driver);
+	uart_unregister_driver(&altera_jtaguart_driver);
+}
+
+module_init(altera_jtaguart_init);
+module_exit(altera_jtaguart_exit);
+
+MODULE_DESCRIPTION("Altera JTAG UART driver");
+MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);