1 files changed, 562 insertions, 0 deletions

diff --git a/drivers/tty/serial/clps711x.c b/drivers/tty/serial/clps711x.c
new file mode 100644
index 000000000..404b43a5a
--- /dev/null
+++ b/drivers/tty/serial/clps711x.c
@@ -0,0 +1,562 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Driver for CLPS711x serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Copyright 1999 ARM Limited
+ *  Copyright (C) 2000 Deep Blue Solutions Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/console.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/ioport.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/clps711x.h>
+
+#include "serial_mctrl_gpio.h"
+
+#define UART_CLPS711X_DEVNAME	"ttyCL"
+#define UART_CLPS711X_NR	2
+#define UART_CLPS711X_MAJOR	204
+#define UART_CLPS711X_MINOR	40
+
+#define UARTDR_OFFSET		(0x00)
+#define UBRLCR_OFFSET		(0x40)
+
+#define UARTDR_FRMERR		(1 << 8)
+#define UARTDR_PARERR		(1 << 9)
+#define UARTDR_OVERR		(1 << 10)
+
+#define UBRLCR_BAUD_MASK	((1 << 12) - 1)
+#define UBRLCR_BREAK		(1 << 12)
+#define UBRLCR_PRTEN		(1 << 13)
+#define UBRLCR_EVENPRT		(1 << 14)
+#define UBRLCR_XSTOP		(1 << 15)
+#define UBRLCR_FIFOEN		(1 << 16)
+#define UBRLCR_WRDLEN5		(0 << 17)
+#define UBRLCR_WRDLEN6		(1 << 17)
+#define UBRLCR_WRDLEN7		(2 << 17)
+#define UBRLCR_WRDLEN8		(3 << 17)
+#define UBRLCR_WRDLEN_MASK	(3 << 17)
+
+struct clps711x_port {
+	struct uart_port	port;
+	unsigned int		tx_enabled;
+	int			rx_irq;
+	struct regmap		*syscon;
+	struct mctrl_gpios	*gpios;
+};
+
+static struct uart_driver clps711x_uart = {
+	.owner		= THIS_MODULE,
+	.driver_name	= UART_CLPS711X_DEVNAME,
+	.dev_name	= UART_CLPS711X_DEVNAME,
+	.major		= UART_CLPS711X_MAJOR,
+	.minor		= UART_CLPS711X_MINOR,
+	.nr		= UART_CLPS711X_NR,
+};
+
+static void uart_clps711x_stop_tx(struct uart_port *port)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	if (s->tx_enabled) {
+		disable_irq(port->irq);
+		s->tx_enabled = 0;
+	}
+}
+
+static void uart_clps711x_start_tx(struct uart_port *port)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	if (!s->tx_enabled) {
+		s->tx_enabled = 1;
+		enable_irq(port->irq);
+	}
+}
+
+static irqreturn_t uart_clps711x_int_rx(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+	unsigned int status, flg;
+	u16 ch;
+
+	for (;;) {
+		u32 sysflg = 0;
+
+		regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
+		if (sysflg & SYSFLG_URXFE)
+			break;
+
+		ch = readw(port->membase + UARTDR_OFFSET);
+		status = ch & (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR);
+		ch &= 0xff;
+
+		port->icount.rx++;
+		flg = TTY_NORMAL;
+
+		if (unlikely(status)) {
+			if (status & UARTDR_PARERR)
+				port->icount.parity++;
+			else if (status & UARTDR_FRMERR)
+				port->icount.frame++;
+			else if (status & UARTDR_OVERR)
+				port->icount.overrun++;
+
+			status &= port->read_status_mask;
+
+			if (status & UARTDR_PARERR)
+				flg = TTY_PARITY;
+			else if (status & UARTDR_FRMERR)
+				flg = TTY_FRAME;
+			else if (status & UARTDR_OVERR)
+				flg = TTY_OVERRUN;
+		}
+
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+
+		if (status & port->ignore_status_mask)
+			continue;
+
+		uart_insert_char(port, status, UARTDR_OVERR, ch, flg);
+	}
+
+	tty_flip_buffer_push(&port->state->port);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t uart_clps711x_int_tx(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (port->x_char) {
+		writew(port->x_char, port->membase + UARTDR_OFFSET);
+		port->icount.tx++;
+		port->x_char = 0;
+		return IRQ_HANDLED;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		if (s->tx_enabled) {
+			disable_irq_nosync(port->irq);
+			s->tx_enabled = 0;
+		}
+		return IRQ_HANDLED;
+	}
+
+	while (!uart_circ_empty(xmit)) {
+		u32 sysflg = 0;
+
+		writew(xmit->buf[xmit->tail], port->membase + UARTDR_OFFSET);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+
+		regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
+		if (sysflg & SYSFLG_UTXFF)
+			break;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int uart_clps711x_tx_empty(struct uart_port *port)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+	u32 sysflg = 0;
+
+	regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
+
+	return (sysflg & SYSFLG_UBUSY) ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int uart_clps711x_get_mctrl(struct uart_port *port)
+{
+	unsigned int result = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	return mctrl_gpio_get(s->gpios, &result);
+}
+
+static void uart_clps711x_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	mctrl_gpio_set(s->gpios, mctrl);
+}
+
+static void uart_clps711x_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned int ubrlcr;
+
+	ubrlcr = readl(port->membase + UBRLCR_OFFSET);
+	if (break_state)
+		ubrlcr |= UBRLCR_BREAK;
+	else
+		ubrlcr &= ~UBRLCR_BREAK;
+	writel(ubrlcr, port->membase + UBRLCR_OFFSET);
+}
+
+static void uart_clps711x_set_ldisc(struct uart_port *port,
+				    struct ktermios *termios)
+{
+	if (!port->line) {
+		struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+		regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON1_SIREN,
+				   (termios->c_line == N_IRDA) ? SYSCON1_SIREN : 0);
+	}
+}
+
+static int uart_clps711x_startup(struct uart_port *port)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	/* Disable break */
+	writel(readl(port->membase + UBRLCR_OFFSET) & ~UBRLCR_BREAK,
+	       port->membase + UBRLCR_OFFSET);
+
+	/* Enable the port */
+	return regmap_update_bits(s->syscon, SYSCON_OFFSET,
+				  SYSCON_UARTEN, SYSCON_UARTEN);
+}
+
+static void uart_clps711x_shutdown(struct uart_port *port)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	/* Disable the port */
+	regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON_UARTEN, 0);
+}
+
+static void uart_clps711x_set_termios(struct uart_port *port,
+				      struct ktermios *termios,
+				      const struct ktermios *old)
+{
+	u32 ubrlcr;
+	unsigned int baud, quot;
+
+	/* Mask termios capabilities we don't support */
+	termios->c_cflag &= ~CMSPAR;
+	termios->c_iflag &= ~(BRKINT | IGNBRK);
+
+	/* Ask the core to calculate the divisor for us */
+	baud = uart_get_baud_rate(port, termios, old, port->uartclk / 4096,
+						      port->uartclk / 16);
+	quot = uart_get_divisor(port, baud);
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		ubrlcr = UBRLCR_WRDLEN5;
+		break;
+	case CS6:
+		ubrlcr = UBRLCR_WRDLEN6;
+		break;
+	case CS7:
+		ubrlcr = UBRLCR_WRDLEN7;
+		break;
+	case CS8:
+	default:
+		ubrlcr = UBRLCR_WRDLEN8;
+		break;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		ubrlcr |= UBRLCR_XSTOP;
+
+	if (termios->c_cflag & PARENB) {
+		ubrlcr |= UBRLCR_PRTEN;
+		if (!(termios->c_cflag & PARODD))
+			ubrlcr |= UBRLCR_EVENPRT;
+	}
+
+	/* Enable FIFO */
+	ubrlcr |= UBRLCR_FIFOEN;
+
+	/* Set read status mask */
+	port->read_status_mask = UARTDR_OVERR;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UARTDR_PARERR | UARTDR_FRMERR;
+
+	/* Set status ignore mask */
+	port->ignore_status_mask = 0;
+	if (!(termios->c_cflag & CREAD))
+		port->ignore_status_mask |= UARTDR_OVERR | UARTDR_PARERR |
+					    UARTDR_FRMERR;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	writel(ubrlcr | (quot - 1), port->membase + UBRLCR_OFFSET);
+}
+
+static const char *uart_clps711x_type(struct uart_port *port)
+{
+	return (port->type == PORT_CLPS711X) ? "CLPS711X" : NULL;
+}
+
+static void uart_clps711x_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_CLPS711X;
+}
+
+static void uart_clps711x_nop_void(struct uart_port *port)
+{
+}
+
+static int uart_clps711x_nop_int(struct uart_port *port)
+{
+	return 0;
+}
+
+static const struct uart_ops uart_clps711x_ops = {
+	.tx_empty	= uart_clps711x_tx_empty,
+	.set_mctrl	= uart_clps711x_set_mctrl,
+	.get_mctrl	= uart_clps711x_get_mctrl,
+	.stop_tx	= uart_clps711x_stop_tx,
+	.start_tx	= uart_clps711x_start_tx,
+	.stop_rx	= uart_clps711x_nop_void,
+	.break_ctl	= uart_clps711x_break_ctl,
+	.set_ldisc	= uart_clps711x_set_ldisc,
+	.startup	= uart_clps711x_startup,
+	.shutdown	= uart_clps711x_shutdown,
+	.set_termios	= uart_clps711x_set_termios,
+	.type		= uart_clps711x_type,
+	.config_port	= uart_clps711x_config_port,
+	.release_port	= uart_clps711x_nop_void,
+	.request_port	= uart_clps711x_nop_int,
+};
+
+#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
+static void uart_clps711x_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+	u32 sysflg = 0;
+
+	/* Wait for FIFO is not full */
+	do {
+		regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
+	} while (sysflg & SYSFLG_UTXFF);
+
+	writew(ch, port->membase + UARTDR_OFFSET);
+}
+
+static void uart_clps711x_console_write(struct console *co, const char *c,
+					unsigned n)
+{
+	struct uart_port *port = clps711x_uart.state[co->index].uart_port;
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+	u32 sysflg = 0;
+
+	uart_console_write(port, c, n, uart_clps711x_console_putchar);
+
+	/* Wait for transmitter to become empty */
+	do {
+		regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
+	} while (sysflg & SYSFLG_UBUSY);
+}
+
+static int uart_clps711x_console_setup(struct console *co, char *options)
+{
+	int baud = 38400, bits = 8, parity = 'n', flow = 'n';
+	int ret, index = co->index;
+	struct clps711x_port *s;
+	struct uart_port *port;
+	unsigned int quot;
+	u32 ubrlcr;
+
+	if (index < 0 || index >= UART_CLPS711X_NR)
+		return -EINVAL;
+
+	port = clps711x_uart.state[index].uart_port;
+	if (!port)
+		return -ENODEV;
+
+	s = dev_get_drvdata(port->dev);
+
+	if (!options) {
+		u32 syscon = 0;
+
+		regmap_read(s->syscon, SYSCON_OFFSET, &syscon);
+		if (syscon & SYSCON_UARTEN) {
+			ubrlcr = readl(port->membase + UBRLCR_OFFSET);
+
+			if (ubrlcr & UBRLCR_PRTEN) {
+				if (ubrlcr & UBRLCR_EVENPRT)
+					parity = 'e';
+				else
+					parity = 'o';
+			}
+
+			if ((ubrlcr & UBRLCR_WRDLEN_MASK) == UBRLCR_WRDLEN7)
+				bits = 7;
+
+			quot = ubrlcr & UBRLCR_BAUD_MASK;
+			baud = port->uartclk / (16 * (quot + 1));
+		}
+	} else
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	ret = uart_set_options(port, co, baud, parity, bits, flow);
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(s->syscon, SYSCON_OFFSET,
+				  SYSCON_UARTEN, SYSCON_UARTEN);
+}
+
+static struct console clps711x_console = {
+	.name	= UART_CLPS711X_DEVNAME,
+	.device	= uart_console_device,
+	.write	= uart_clps711x_console_write,
+	.setup	= uart_clps711x_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+};
+#endif
+
+static int uart_clps711x_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct clps711x_port *s;
+	struct resource *res;
+	struct clk *uart_clk;
+	int irq, ret;
+
+	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+
+	uart_clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(uart_clk))
+		return PTR_ERR(uart_clk);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	s->port.membase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(s->port.membase))
+		return PTR_ERR(s->port.membase);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	s->port.irq = irq;
+
+	s->rx_irq = platform_get_irq(pdev, 1);
+	if (s->rx_irq < 0)
+		return s->rx_irq;
+
+	s->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
+	if (IS_ERR(s->syscon))
+		return PTR_ERR(s->syscon);
+
+	s->port.line		= of_alias_get_id(np, "serial");
+	s->port.dev		= &pdev->dev;
+	s->port.iotype		= UPIO_MEM32;
+	s->port.mapbase		= res->start;
+	s->port.type		= PORT_CLPS711X;
+	s->port.fifosize	= 16;
+	s->port.has_sysrq	= IS_ENABLED(CONFIG_SERIAL_CLPS711X_CONSOLE);
+	s->port.flags		= UPF_SKIP_TEST | UPF_FIXED_TYPE;
+	s->port.uartclk		= clk_get_rate(uart_clk);
+	s->port.ops		= &uart_clps711x_ops;
+
+	platform_set_drvdata(pdev, s);
+
+	s->gpios = mctrl_gpio_init_noauto(&pdev->dev, 0);
+	if (IS_ERR(s->gpios))
+	    return PTR_ERR(s->gpios);
+
+	ret = uart_add_one_port(&clps711x_uart, &s->port);
+	if (ret)
+		return ret;
+
+	/* Disable port */
+	if (!uart_console(&s->port))
+		regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON_UARTEN, 0);
+
+	s->tx_enabled = 1;
+
+	ret = devm_request_irq(&pdev->dev, s->port.irq, uart_clps711x_int_tx, 0,
+			       dev_name(&pdev->dev), &s->port);
+	if (ret) {
+		uart_remove_one_port(&clps711x_uart, &s->port);
+		return ret;
+	}
+
+	ret = devm_request_irq(&pdev->dev, s->rx_irq, uart_clps711x_int_rx, 0,
+			       dev_name(&pdev->dev), &s->port);
+	if (ret)
+		uart_remove_one_port(&clps711x_uart, &s->port);
+
+	return ret;
+}
+
+static int uart_clps711x_remove(struct platform_device *pdev)
+{
+	struct clps711x_port *s = platform_get_drvdata(pdev);
+
+	return uart_remove_one_port(&clps711x_uart, &s->port);
+}
+
+static const struct of_device_id __maybe_unused clps711x_uart_dt_ids[] = {
+	{ .compatible = "cirrus,ep7209-uart", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, clps711x_uart_dt_ids);
+
+static struct platform_driver clps711x_uart_platform = {
+	.driver = {
+		.name		= "clps711x-uart",
+		.of_match_table	= of_match_ptr(clps711x_uart_dt_ids),
+	},
+	.probe	= uart_clps711x_probe,
+	.remove	= uart_clps711x_remove,
+};
+
+static int __init uart_clps711x_init(void)
+{
+	int ret;
+
+#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
+	clps711x_uart.cons = &clps711x_console;
+	clps711x_console.data = &clps711x_uart;
+#endif
+
+	ret = uart_register_driver(&clps711x_uart);
+	if (ret)
+		return ret;
+
+	return platform_driver_register(&clps711x_uart_platform);
+}
+module_init(uart_clps711x_init);
+
+static void __exit uart_clps711x_exit(void)
+{
+	platform_driver_unregister(&clps711x_uart_platform);
+	uart_unregister_driver(&clps711x_uart);
+}
+module_exit(uart_clps711x_exit);
+
+MODULE_AUTHOR("Deep Blue Solutions Ltd");
+MODULE_DESCRIPTION("CLPS711X serial driver");
+MODULE_LICENSE("GPL");