Release 4.7 drivers/tty/serial/digicolor-usart.c

Directory: drivers/tty/serial
/*
 *  Driver for Conexant Digicolor serial ports (USART)
 *
 * Author: Baruch Siach <baruch@tkos.co.il>
 *
 * Copyright (C) 2014 Paradox Innovation Ltd.
 *
 * 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.
 */

#include <linux/module.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/of.h>
#include <linux/platform_device.h>
#include <linux/workqueue.h>


#define UA_ENABLE			0x00

#define UA_ENABLE_ENABLE		BIT(0)


#define UA_CONTROL			0x01

#define UA_CONTROL_RX_ENABLE		BIT(0)

#define UA_CONTROL_TX_ENABLE		BIT(1)

#define UA_CONTROL_SOFT_RESET		BIT(2)


#define UA_STATUS			0x02

#define UA_STATUS_PARITY_ERR		BIT(0)

#define UA_STATUS_FRAME_ERR		BIT(1)

#define UA_STATUS_OVERRUN_ERR		BIT(2)

#define UA_STATUS_TX_READY		BIT(6)


#define UA_CONFIG			0x03

#define UA_CONFIG_CHAR_LEN		BIT(0)

#define UA_CONFIG_STOP_BITS		BIT(1)

#define UA_CONFIG_PARITY		BIT(2)

#define UA_CONFIG_ODD_PARITY		BIT(4)


#define UA_EMI_REC			0x04


#define UA_HBAUD_LO			0x08

#define UA_HBAUD_HI			0x09


#define UA_STATUS_FIFO			0x0a

#define UA_STATUS_FIFO_RX_EMPTY		BIT(2)

#define UA_STATUS_FIFO_RX_INT_ALMOST	BIT(3)

#define UA_STATUS_FIFO_TX_FULL		BIT(4)

#define UA_STATUS_FIFO_TX_INT_ALMOST	BIT(7)


#define UA_CONFIG_FIFO			0x0b

#define UA_CONFIG_FIFO_RX_THRESH	7

#define UA_CONFIG_FIFO_RX_FIFO_MODE	BIT(3)

#define UA_CONFIG_FIFO_TX_FIFO_MODE	BIT(7)


#define UA_INTFLAG_CLEAR		0x1c

#define UA_INTFLAG_SET			0x1d

#define UA_INT_ENABLE			0x1e

#define UA_INT_STATUS			0x1f


#define UA_INT_TX			BIT(0)

#define UA_INT_RX			BIT(1)


#define DIGICOLOR_USART_NR		3

/*
 * We use the 16 bytes hardware FIFO to buffer Rx traffic. Rx interrupt is
 * only produced when the FIFO is filled more than a certain configurable
 * threshold. Unfortunately, there is no way to set this threshold below half
 * FIFO. This means that we must periodically poll the FIFO status register to
 * see whether there are waiting Rx bytes.
 */


struct digicolor_port {
	
struct uart_port port;
	
struct delayed_work rx_poll_work;
};


static struct uart_port *digicolor_ports[DIGICOLOR_USART_NR];



static bool digicolor_uart_tx_full(struct uart_port *port)
{
	return !!(readb_relaxed(port->membase + UA_STATUS_FIFO) &
		  UA_STATUS_FIFO_TX_FULL);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 27 100.00% 1 100.00%
Total 27 100.00% 1 100.00%



static bool digicolor_uart_rx_empty(struct uart_port *port)
{
	return !!(readb_relaxed(port->membase + UA_STATUS_FIFO) &
		  UA_STATUS_FIFO_RX_EMPTY);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 27 100.00% 1 100.00%
Total 27 100.00% 1 100.00%



static void digicolor_uart_stop_tx(struct uart_port *port)
{
	u8 int_enable = readb_relaxed(port->membase + UA_INT_ENABLE);

	int_enable &= ~UA_INT_TX;
	writeb_relaxed(int_enable, port->membase + UA_INT_ENABLE);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 39 100.00% 1 100.00%
Total 39 100.00% 1 100.00%



static void digicolor_uart_start_tx(struct uart_port *port)
{
	u8 int_enable = readb_relaxed(port->membase + UA_INT_ENABLE);

	int_enable |= UA_INT_TX;
	writeb_relaxed(int_enable, port->membase + UA_INT_ENABLE);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 38 100.00% 1 100.00%
Total 38 100.00% 1 100.00%



static void digicolor_uart_stop_rx(struct uart_port *port)
{
	u8 int_enable = readb_relaxed(port->membase + UA_INT_ENABLE);

	int_enable &= ~UA_INT_RX;
	writeb_relaxed(int_enable, port->membase + UA_INT_ENABLE);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 39 100.00% 1 100.00%
Total 39 100.00% 1 100.00%



static void digicolor_rx_poll(struct work_struct *work)
{
	struct digicolor_port *dp =
		container_of(to_delayed_work(work),
			     struct digicolor_port, rx_poll_work);

	if (!digicolor_uart_rx_empty(&dp->port))
		/* force RX interrupt */
		writeb_relaxed(UA_INT_RX, dp->port.membase + UA_INTFLAG_SET);

	schedule_delayed_work(&dp->rx_poll_work, msecs_to_jiffies(100));
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 67 100.00% 1 100.00%
Total 67 100.00% 1 100.00%



static void digicolor_uart_rx(struct uart_port *port)
{
	unsigned long flags;

	spin_lock_irqsave(&port->lock, flags);

	while (1) {
		u8 status, ch;
		unsigned int ch_flag;

		if (digicolor_uart_rx_empty(port))
			break;

		ch = readb_relaxed(port->membase + UA_EMI_REC);
		status = readb_relaxed(port->membase + UA_STATUS);

		port->icount.rx++;
		ch_flag = TTY_NORMAL;

		if (status) {
			if (status & UA_STATUS_PARITY_ERR)
				port->icount.parity++;
			else if (status & UA_STATUS_FRAME_ERR)
				port->icount.frame++;
			else if (status & UA_STATUS_OVERRUN_ERR)
				port->icount.overrun++;

			status &= port->read_status_mask;

			if (status & UA_STATUS_PARITY_ERR)
				ch_flag = TTY_PARITY;
			else if (status & UA_STATUS_FRAME_ERR)
				ch_flag = TTY_FRAME;
			else if (status & UA_STATUS_OVERRUN_ERR)
				ch_flag = TTY_OVERRUN;
		}

		if (status & port->ignore_status_mask)
			continue;

		uart_insert_char(port, status, UA_STATUS_OVERRUN_ERR, ch,
				 ch_flag);
	}

	spin_unlock_irqrestore(&port->lock, flags);

	tty_flip_buffer_push(&port->state->port);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 208 100.00% 1 100.00%
Total 208 100.00% 1 100.00%



static void digicolor_uart_tx(struct uart_port *port)
{
	struct circ_buf *xmit = &port->state->xmit;
	unsigned long flags;

	if (digicolor_uart_tx_full(port))
		return;

	spin_lock_irqsave(&port->lock, flags);

	if (port->x_char) {
		writeb_relaxed(port->x_char, port->membase + UA_EMI_REC);
		port->icount.tx++;
		port->x_char = 0;
		goto out;
	}

	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
		digicolor_uart_stop_tx(port);
		goto out;
	}

	while (!uart_circ_empty(xmit)) {
		writeb(xmit->buf[xmit->tail], port->membase + UA_EMI_REC);
		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
		port->icount.tx++;

		if (digicolor_uart_tx_full(port))
			break;
	}

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(port);

out:
	spin_unlock_irqrestore(&port->lock, flags);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 191 100.00% 1 100.00%
Total 191 100.00% 1 100.00%



static irqreturn_t digicolor_uart_int(int irq, void *dev_id)
{
	struct uart_port *port = dev_id;
	u8 int_status = readb_relaxed(port->membase + UA_INT_STATUS);

	writeb_relaxed(UA_INT_RX | UA_INT_TX,
		       port->membase + UA_INTFLAG_CLEAR);

	if (int_status & UA_INT_RX)
		digicolor_uart_rx(port);
	if (int_status & UA_INT_TX)
		digicolor_uart_tx(port);

	return IRQ_HANDLED;
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 70 100.00% 1 100.00%
Total 70 100.00% 1 100.00%



static unsigned int digicolor_uart_tx_empty(struct uart_port *port)
{
	u8 status = readb_relaxed(port->membase + UA_STATUS);

	return (status & UA_STATUS_TX_READY) ? TIOCSER_TEMT : 0;
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 35 100.00% 1 100.00%
Total 35 100.00% 1 100.00%



static unsigned int digicolor_uart_get_mctrl(struct uart_port *port)
{
	return TIOCM_CTS;
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 15 100.00% 1 100.00%
Total 15 100.00% 1 100.00%



static void digicolor_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 14 100.00% 1 100.00%
Total 14 100.00% 1 100.00%



static void digicolor_uart_break_ctl(struct uart_port *port, int state)
{
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 13 100.00% 1 100.00%
Total 13 100.00% 1 100.00%



static int digicolor_uart_startup(struct uart_port *port)
{
	struct digicolor_port *dp =
		container_of(port, struct digicolor_port, port);

	writeb_relaxed(UA_ENABLE_ENABLE, port->membase + UA_ENABLE);
	writeb_relaxed(UA_CONTROL_SOFT_RESET, port->membase + UA_CONTROL);
	writeb_relaxed(0, port->membase + UA_CONTROL);

	writeb_relaxed(UA_CONFIG_FIFO_RX_FIFO_MODE
		       | UA_CONFIG_FIFO_TX_FIFO_MODE | UA_CONFIG_FIFO_RX_THRESH,
		       port->membase + UA_CONFIG_FIFO);
	writeb_relaxed(UA_STATUS_FIFO_RX_INT_ALMOST,
		       port->membase + UA_STATUS_FIFO);
	writeb_relaxed(UA_CONTROL_RX_ENABLE | UA_CONTROL_TX_ENABLE,
		       port->membase + UA_CONTROL);
	writeb_relaxed(UA_INT_TX | UA_INT_RX,
		       port->membase + UA_INT_ENABLE);

	schedule_delayed_work(&dp->rx_poll_work, msecs_to_jiffies(100));

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 127 100.00% 1 100.00%
Total 127 100.00% 1 100.00%



static void digicolor_uart_shutdown(struct uart_port *port)
{
	struct digicolor_port *dp =
		container_of(port, struct digicolor_port, port);

	writeb_relaxed(0, port->membase + UA_ENABLE);
	cancel_delayed_work_sync(&dp->rx_poll_work);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 45 100.00% 1 100.00%
Total 45 100.00% 1 100.00%



static void digicolor_uart_set_termios(struct uart_port *port,
				       struct ktermios *termios,
				       struct ktermios *old)
{
	unsigned int baud, divisor;
	u8 config = 0;
	unsigned long flags;

	/* Mask termios capabilities we don't support */
	termios->c_cflag &= ~CMSPAR;
	termios->c_iflag &= ~(BRKINT | IGNBRK);

	/* Limit baud rates so that we don't need the fractional divider */
	baud = uart_get_baud_rate(port, termios, old,
				  port->uartclk / (0x10000*16),
				  port->uartclk / 256);
	divisor = uart_get_divisor(port, baud) - 1;

	switch (termios->c_cflag & CSIZE) {
	case CS7:
		break;
	case CS8:
	default:
		config |= UA_CONFIG_CHAR_LEN;
		break;
	}

	if (termios->c_cflag & CSTOPB)
		config |= UA_CONFIG_STOP_BITS;

	if (termios->c_cflag & PARENB) {
		config |= UA_CONFIG_PARITY;
		if (termios->c_cflag & PARODD)
			config |= UA_CONFIG_ODD_PARITY;
	}

	/* Set read status mask */
	port->read_status_mask = UA_STATUS_OVERRUN_ERR;
	if (termios->c_iflag & INPCK)
		port->read_status_mask |= UA_STATUS_PARITY_ERR
			| UA_STATUS_FRAME_ERR;

	/* Set status ignore mask */
	port->ignore_status_mask = 0;
	if (!(termios->c_cflag & CREAD))
		port->ignore_status_mask |= UA_STATUS_OVERRUN_ERR
			| UA_STATUS_PARITY_ERR | UA_STATUS_FRAME_ERR;

	spin_lock_irqsave(&port->lock, flags);

	uart_update_timeout(port, termios->c_cflag, baud);

	writeb_relaxed(config, port->membase + UA_CONFIG);
	writeb_relaxed(divisor & 0xff, port->membase + UA_HBAUD_LO);
	writeb_relaxed(divisor >> 8, port->membase + UA_HBAUD_HI);

	spin_unlock_irqrestore(&port->lock, flags);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 274 100.00% 1 100.00%
Total 274 100.00% 1 100.00%



static const char *digicolor_uart_type(struct uart_port *port)
{
	return (port->type == PORT_DIGICOLOR) ? "DIGICOLOR USART" : NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 26 100.00% 1 100.00%
Total 26 100.00% 1 100.00%



static void digicolor_uart_config_port(struct uart_port *port, int flags)
{
	if (flags & UART_CONFIG_TYPE)
		port->type = PORT_DIGICOLOR;
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 26 100.00% 1 100.00%
Total 26 100.00% 1 100.00%



static void digicolor_uart_release_port(struct uart_port *port)
{
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 10 100.00% 1 100.00%
Total 10 100.00% 1 100.00%



static int digicolor_uart_request_port(struct uart_port *port)
{
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 14 100.00% 1 100.00%
Total 14 100.00% 1 100.00%


static const struct uart_ops digicolor_uart_ops = {
	.tx_empty	= digicolor_uart_tx_empty,
	.set_mctrl	= digicolor_uart_set_mctrl,
	.get_mctrl	= digicolor_uart_get_mctrl,
	.stop_tx	= digicolor_uart_stop_tx,
	.start_tx	= digicolor_uart_start_tx,
	.stop_rx	= digicolor_uart_stop_rx,
	.break_ctl	= digicolor_uart_break_ctl,
	.startup	= digicolor_uart_startup,
	.shutdown	= digicolor_uart_shutdown,
	.set_termios	= digicolor_uart_set_termios,
	.type		= digicolor_uart_type,
	.config_port	= digicolor_uart_config_port,
	.release_port	= digicolor_uart_release_port,
	.request_port	= digicolor_uart_request_port,
};



static void digicolor_uart_console_putchar(struct uart_port *port, int ch)
{
	while (digicolor_uart_tx_full(port))
		cpu_relax();

	writeb_relaxed(ch, port->membase + UA_EMI_REC);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 35 100.00% 1 100.00%
Total 35 100.00% 1 100.00%



static void digicolor_uart_console_write(struct console *co, const char *c,
					 unsigned n)
{
	struct uart_port *port = digicolor_ports[co->index];
	u8 status;
	unsigned long flags;
	int locked = 1;

	if (oops_in_progress)
		locked = spin_trylock_irqsave(&port->lock, flags);
	else
		spin_lock_irqsave(&port->lock, flags);

	uart_console_write(port, c, n, digicolor_uart_console_putchar);

	if (locked)
		spin_unlock_irqrestore(&port->lock, flags);

	/* Wait for transmitter to become empty */
	do {
		status = readb_relaxed(port->membase + UA_STATUS);
	} while ((status & UA_STATUS_TX_READY) == 0);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 121 100.00% 1 100.00%
Total 121 100.00% 1 100.00%



static int digicolor_uart_console_setup(struct console *co, char *options)
{
	int baud = 115200, bits = 8, parity = 'n', flow = 'n';
	struct uart_port *port;

	if (co->index < 0 || co->index >= DIGICOLOR_USART_NR)
		return -EINVAL;

	port = digicolor_ports[co->index];
	if (!port)
		return -ENODEV;

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);

	return uart_set_options(port, co, baud, parity, bits, flow);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 110 100.00% 1 100.00%
Total 110 100.00% 1 100.00%


static struct console digicolor_console = {
	.name	= "ttyS",
	.device	= uart_console_device,
	.write	= digicolor_uart_console_write,
	.setup	= digicolor_uart_console_setup,
	.flags	= CON_PRINTBUFFER,
	.index	= -1,
};


static struct uart_driver digicolor_uart = {
	.driver_name	= "digicolor-usart",
	.dev_name	= "ttyS",
	.nr		= DIGICOLOR_USART_NR,
};



static int digicolor_uart_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	int irq, ret, index;
	struct digicolor_port *dp;
	struct resource *res;
	struct clk *uart_clk;

	if (!np) {
		dev_err(&pdev->dev, "Missing device tree node\n");
		return -ENXIO;
	}

	index = of_alias_get_id(np, "serial");
	if (index < 0 || index >= DIGICOLOR_USART_NR)
		return -EINVAL;

	dp = devm_kzalloc(&pdev->dev, sizeof(*dp), GFP_KERNEL);
	if (!dp)
		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);
	dp->port.mapbase = res->start;
	dp->port.membase = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(dp->port.membase))
		return PTR_ERR(dp->port.membase);

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;
	dp->port.irq = irq;

	dp->port.iotype = UPIO_MEM;
	dp->port.uartclk = clk_get_rate(uart_clk);
	dp->port.fifosize = 16;
	dp->port.dev = &pdev->dev;
	dp->port.ops = &digicolor_uart_ops;
	dp->port.line = index;
	dp->port.type = PORT_DIGICOLOR;
	spin_lock_init(&dp->port.lock);

	digicolor_ports[index] = &dp->port;
	platform_set_drvdata(pdev, &dp->port);

	INIT_DELAYED_WORK(&dp->rx_poll_work, digicolor_rx_poll);

	ret = devm_request_irq(&pdev->dev, dp->port.irq, digicolor_uart_int, 0,
			       dev_name(&pdev->dev), &dp->port);
	if (ret)
		return ret;

	return uart_add_one_port(&digicolor_uart, &dp->port);
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 370 97.63% 1 50.00%
guenter roeck guenter roeck 9 2.37% 1 50.00%
Total 379 100.00% 2 100.00%



static int digicolor_uart_remove(struct platform_device *pdev)
{
	struct uart_port *port = platform_get_drvdata(pdev);

	uart_remove_one_port(&digicolor_uart, port);

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 32 100.00% 1 100.00%
Total 32 100.00% 1 100.00%


static const struct of_device_id digicolor_uart_dt_ids[] = {
	{ .compatible = "cnxt,cx92755-usart", },
	{ }
};
MODULE_DEVICE_TABLE(of, digicolor_uart_dt_ids);


static struct platform_driver digicolor_uart_platform = {
	.driver = {
		.name		= "digicolor-usart",
		.of_match_table	= of_match_ptr(digicolor_uart_dt_ids),
        },
	.probe	= digicolor_uart_probe,
	.remove	= digicolor_uart_remove,
};



static int __init digicolor_uart_init(void)
{
	int ret;

	if (IS_ENABLED(CONFIG_SERIAL_CONEXANT_DIGICOLOR_CONSOLE)) {
		digicolor_uart.cons = &digicolor_console;
		digicolor_console.data = &digicolor_uart;
	}

	ret = uart_register_driver(&digicolor_uart);
	if (ret)
		return ret;

	return platform_driver_register(&digicolor_uart_platform);
}
Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 57 100.00% 1 100.00%
Total 57 100.00% 1 100.00%


module_init(digicolor_uart_init);



static void __exit digicolor_uart_exit(void)
{
	platform_driver_unregister(&digicolor_uart_platform);
	uart_unregister_driver(&digicolor_uart);
}
Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 21 100.00% 1 100.00%
Total 21 100.00% 1 100.00%


module_exit(digicolor_uart_exit);

MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
MODULE_DESCRIPTION("Conexant Digicolor USART serial driver");
MODULE_LICENSE("GPL");
Overall Contributors
Person Tokens Prop Commits CommitProp
baruch siach baruch siach 2471 99.64% 1 50.00%
guenter roeck guenter roeck 9 0.36% 1 50.00%
Total 2480 100.00% 2 100.00%
  Directory: drivers/tty/serial

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
	Person	Tokens	Prop	Commits	CommitProp
baruch siach	baruch siach	27	100.00%	1	100.00%
	Total	27	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.7 drivers/tty/serial/digicolor-usart.c

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Overall Contributors
