--- /dev/null
+/*
+ * altera_uart.c -- Altera 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>
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/console.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_uart.h>
+
+#define DRV_NAME "altera_uart"
+
+/*
+ * Altera UART register definitions according to the Nios UART datasheet:
+ * http://www.altera.com/literature/ds/ds_nios_uart.pdf
+ */
+
+#define ALTERA_UART_SIZE 32
+
+#define ALTERA_UART_RXDATA_REG 0
+#define ALTERA_UART_TXDATA_REG 4
+#define ALTERA_UART_STATUS_REG 8
+#define ALTERA_UART_CONTROL_REG 12
+#define ALTERA_UART_DIVISOR_REG 16
+#define ALTERA_UART_EOP_REG 20
+
+#define ALTERA_UART_STATUS_PE_MSK 0x0001 /* parity error */
+#define ALTERA_UART_STATUS_FE_MSK 0x0002 /* framing error */
+#define ALTERA_UART_STATUS_BRK_MSK 0x0004 /* break */
+#define ALTERA_UART_STATUS_ROE_MSK 0x0008 /* RX overrun error */
+#define ALTERA_UART_STATUS_TOE_MSK 0x0010 /* TX overrun error */
+#define ALTERA_UART_STATUS_TMT_MSK 0x0020 /* TX shift register state */
+#define ALTERA_UART_STATUS_TRDY_MSK 0x0040 /* TX ready */
+#define ALTERA_UART_STATUS_RRDY_MSK 0x0080 /* RX ready */
+#define ALTERA_UART_STATUS_E_MSK 0x0100 /* exception condition */
+#define ALTERA_UART_STATUS_DCTS_MSK 0x0400 /* CTS logic-level change */
+#define ALTERA_UART_STATUS_CTS_MSK 0x0800 /* CTS logic state */
+#define ALTERA_UART_STATUS_EOP_MSK 0x1000 /* EOP written/read */
+
+ /* Enable interrupt on... */
+#define ALTERA_UART_CONTROL_PE_MSK 0x0001 /* ...parity error */
+#define ALTERA_UART_CONTROL_FE_MSK 0x0002 /* ...framing error */
+#define ALTERA_UART_CONTROL_BRK_MSK 0x0004 /* ...break */
+#define ALTERA_UART_CONTROL_ROE_MSK 0x0008 /* ...RX overrun */
+#define ALTERA_UART_CONTROL_TOE_MSK 0x0010 /* ...TX overrun */
+#define ALTERA_UART_CONTROL_TMT_MSK 0x0020 /* ...TX shift register empty */
+#define ALTERA_UART_CONTROL_TRDY_MSK 0x0040 /* ...TX ready */
+#define ALTERA_UART_CONTROL_RRDY_MSK 0x0080 /* ...RX ready */
+#define ALTERA_UART_CONTROL_E_MSK 0x0100 /* ...exception*/
+
+#define ALTERA_UART_CONTROL_TRBK_MSK 0x0200 /* TX break */
+#define ALTERA_UART_CONTROL_DCTS_MSK 0x0400 /* Interrupt on CTS change */
+#define ALTERA_UART_CONTROL_RTS_MSK 0x0800 /* RTS signal */
+#define ALTERA_UART_CONTROL_EOP_MSK 0x1000 /* Interrupt on EOP */
+
+/*
+ * Local per-uart structure.
+ */
+struct altera_uart {
+ struct uart_port port;
+ unsigned int sigs; /* Local copy of line sigs */
+ unsigned short imr; /* Local IMR mirror */
+};
+
+static unsigned int altera_uart_tx_empty(struct uart_port *port)
+{
+ return (readl(port->membase + ALTERA_UART_STATUS_REG) &
+ ALTERA_UART_STATUS_TMT_MSK) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int altera_uart_get_mctrl(struct uart_port *port)
+{
+ struct altera_uart *pp = container_of(port, struct altera_uart, port);
+ unsigned long flags;
+ unsigned int sigs;
+
+ spin_lock_irqsave(&port->lock, flags);
+ sigs =
+ (readl(port->membase + ALTERA_UART_STATUS_REG) &
+ ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0;
+ sigs |= (pp->sigs & TIOCM_RTS);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return sigs;
+}
+
+static void altera_uart_set_mctrl(struct uart_port *port, unsigned int sigs)
+{
+ struct altera_uart *pp = container_of(port, struct altera_uart, port);
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ pp->sigs = sigs;
+ if (sigs & TIOCM_RTS)
+ pp->imr |= ALTERA_UART_CONTROL_RTS_MSK;
+ else
+ pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK;
+ writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void altera_uart_start_tx(struct uart_port *port)
+{
+ struct altera_uart *pp = container_of(port, struct altera_uart, port);
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ pp->imr |= ALTERA_UART_CONTROL_TRDY_MSK;
+ writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void altera_uart_stop_tx(struct uart_port *port)
+{
+ struct altera_uart *pp = container_of(port, struct altera_uart, port);
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
+ writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void altera_uart_stop_rx(struct uart_port *port)
+{
+ struct altera_uart *pp = container_of(port, struct altera_uart, port);
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ pp->imr &= ~ALTERA_UART_CONTROL_RRDY_MSK;
+ writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void altera_uart_break_ctl(struct uart_port *port, int break_state)
+{
+ struct altera_uart *pp = container_of(port, struct altera_uart, port);
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ if (break_state == -1)
+ pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK;
+ else
+ pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK;
+ writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void altera_uart_enable_ms(struct uart_port *port)
+{
+}
+
+static void altera_uart_set_termios(struct uart_port *port,
+ struct ktermios *termios,
+ struct ktermios *old)
+{
+ unsigned long flags;
+ unsigned int baud, baudclk;
+
+ baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
+ baudclk = port->uartclk / baud;
+
+ if (old)
+ tty_termios_copy_hw(termios, old);
+ tty_termios_encode_baud_rate(termios, baud, baud);
+
+ spin_lock_irqsave(&port->lock, flags);
+ writel(baudclk, port->membase + ALTERA_UART_DIVISOR_REG);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void altera_uart_rx_chars(struct altera_uart *pp)
+{
+ struct uart_port *port = &pp->port;
+ unsigned char ch, flag;
+ unsigned short status;
+
+ while ((status = readl(port->membase + ALTERA_UART_STATUS_REG)) &
+ ALTERA_UART_STATUS_RRDY_MSK) {
+ ch = readl(port->membase + ALTERA_UART_RXDATA_REG);
+ flag = TTY_NORMAL;
+ port->icount.rx++;
+
+ if (status & ALTERA_UART_STATUS_E_MSK) {
+ writel(status, port->membase + ALTERA_UART_STATUS_REG);
+
+ if (status & ALTERA_UART_STATUS_BRK_MSK) {
+ port->icount.brk++;
+ if (uart_handle_break(port))
+ continue;
+ } else if (status & ALTERA_UART_STATUS_PE_MSK) {
+ port->icount.parity++;
+ } else if (status & ALTERA_UART_STATUS_ROE_MSK) {
+ port->icount.overrun++;
+ } else if (status & ALTERA_UART_STATUS_FE_MSK) {
+ port->icount.frame++;
+ }
+
+ status &= port->read_status_mask;
+
+ if (status & ALTERA_UART_STATUS_BRK_MSK)
+ flag = TTY_BREAK;
+ else if (status & ALTERA_UART_STATUS_PE_MSK)
+ flag = TTY_PARITY;
+ else if (status & ALTERA_UART_STATUS_FE_MSK)
+ flag = TTY_FRAME;
+ }
+
+ if (uart_handle_sysrq_char(port, ch))
+ continue;
+ uart_insert_char(port, status, ALTERA_UART_STATUS_ROE_MSK, ch,
+ flag);
+ }
+
+ tty_flip_buffer_push(port->state->port.tty);
+}
+
+static void altera_uart_tx_chars(struct altera_uart *pp)
+{
+ struct uart_port *port = &pp->port;
+ struct circ_buf *xmit = &port->state->xmit;
+
+ if (port->x_char) {
+ /* Send special char - probably flow control */
+ writel(port->x_char, port->membase + ALTERA_UART_TXDATA_REG);
+ port->x_char = 0;
+ port->icount.tx++;
+ return;
+ }
+
+ while (readl(port->membase + ALTERA_UART_STATUS_REG) &
+ ALTERA_UART_STATUS_TRDY_MSK) {
+ if (xmit->head == xmit->tail)
+ break;
+ writel(xmit->buf[xmit->tail],
+ port->membase + ALTERA_UART_TXDATA_REG);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ port->icount.tx++;
+ }
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+
+ if (xmit->head == xmit->tail) {
+ pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
+ writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+ }
+}
+
+static irqreturn_t altera_uart_interrupt(int irq, void *data)
+{
+ struct uart_port *port = data;
+ struct altera_uart *pp = container_of(port, struct altera_uart, port);
+ unsigned int isr;
+
+ isr = readl(port->membase + ALTERA_UART_STATUS_REG) & pp->imr;
+ if (isr & ALTERA_UART_STATUS_RRDY_MSK)
+ altera_uart_rx_chars(pp);
+ if (isr & ALTERA_UART_STATUS_TRDY_MSK)
+ altera_uart_tx_chars(pp);
+ return IRQ_RETVAL(isr);
+}
+
+static void altera_uart_config_port(struct uart_port *port, int flags)
+{
+ port->type = PORT_ALTERA_UART;
+
+ /* Clear mask, so no surprise interrupts. */
+ writel(0, port->membase + ALTERA_UART_CONTROL_REG);
+ /* Clear status register */
+ writel(0, port->membase + ALTERA_UART_STATUS_REG);
+}
+
+static int altera_uart_startup(struct uart_port *port)
+{
+ struct altera_uart *pp = container_of(port, struct altera_uart, port);
+ unsigned long flags;
+ int ret;
+
+ ret = request_irq(port->irq, altera_uart_interrupt, IRQF_DISABLED,
+ DRV_NAME, port);
+ if (ret) {
+ pr_err(DRV_NAME ": unable to attach Altera UART %d "
+ "interrupt vector=%d\n", port->line, port->irq);
+ return ret;
+ }
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ /* Enable RX interrupts now */
+ pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
+ writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return 0;
+}
+
+static void altera_uart_shutdown(struct uart_port *port)
+{
+ struct altera_uart *pp = container_of(port, struct altera_uart, port);
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ /* Disable all interrupts now */
+ pp->imr = 0;
+ writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ free_irq(port->irq, port);
+}
+
+static const char *altera_uart_type(struct uart_port *port)
+{
+ return (port->type == PORT_ALTERA_UART) ? "Altera UART" : NULL;
+}
+
+static int altera_uart_request_port(struct uart_port *port)
+{
+ /* UARTs always present */
+ return 0;
+}
+
+static void altera_uart_release_port(struct uart_port *port)
+{
+ /* Nothing to release... */
+}
+
+static int altera_uart_verify_port(struct uart_port *port,
+ struct serial_struct *ser)
+{
+ if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_ALTERA_UART))
+ return -EINVAL;
+ return 0;
+}
+
+/*
+ * Define the basic serial functions we support.
+ */
+static struct uart_ops altera_uart_ops = {
+ .tx_empty = altera_uart_tx_empty,
+ .get_mctrl = altera_uart_get_mctrl,
+ .set_mctrl = altera_uart_set_mctrl,
+ .start_tx = altera_uart_start_tx,
+ .stop_tx = altera_uart_stop_tx,
+ .stop_rx = altera_uart_stop_rx,
+ .enable_ms = altera_uart_enable_ms,
+ .break_ctl = altera_uart_break_ctl,
+ .startup = altera_uart_startup,
+ .shutdown = altera_uart_shutdown,
+ .set_termios = altera_uart_set_termios,
+ .type = altera_uart_type,
+ .request_port = altera_uart_request_port,
+ .release_port = altera_uart_release_port,
+ .config_port = altera_uart_config_port,
+ .verify_port = altera_uart_verify_port,
+};
+
+static struct altera_uart altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS];
+
+#if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
+
+int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp)
+{
+ struct uart_port *port;
+ int i;
+
+ for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS && platp[i].mapbase; i++) {
+ port = &altera_uart_ports[i].port;
+
+ port->line = i;
+ port->type = PORT_ALTERA_UART;
+ port->mapbase = platp[i].mapbase;
+ port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
+ port->iotype = SERIAL_IO_MEM;
+ port->irq = platp[i].irq;
+ port->uartclk = platp[i].uartclk;
+ port->flags = ASYNC_BOOT_AUTOCONF;
+ port->ops = &altera_uart_ops;
+ }
+
+ return 0;
+}
+
+static void altera_uart_console_putc(struct console *co, const char c)
+{
+ struct uart_port *port = &(altera_uart_ports + co->index)->port;
+ int i;
+
+ for (i = 0; i < 0x10000; i++) {
+ if (readl(port->membase + ALTERA_UART_STATUS_REG) &
+ ALTERA_UART_STATUS_TRDY_MSK)
+ break;
+ }
+ writel(c, port->membase + ALTERA_UART_TXDATA_REG);
+ for (i = 0; i < 0x10000; i++) {
+ if (readl(port->membase + ALTERA_UART_STATUS_REG) &
+ ALTERA_UART_STATUS_TRDY_MSK)
+ break;
+ }
+}
+
+static void altera_uart_console_write(struct console *co, const char *s,
+ unsigned int count)
+{
+ for (; count; count--, s++) {
+ altera_uart_console_putc(co, *s);
+ if (*s == '\n')
+ altera_uart_console_putc(co, '\r');
+ }
+}
+
+static int __init altera_uart_console_setup(struct console *co, char *options)
+{
+ struct uart_port *port;
+ int baud = CONFIG_SERIAL_ALTERA_UART_BAUDRATE;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ if (co->index < 0 || co->index >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
+ return -EINVAL;
+ port = &altera_uart_ports[co->index].port;
+ if (port->membase == 0)
+ return -ENODEV;
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+ return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver altera_uart_driver;
+
+static struct console altera_uart_console = {
+ .name = "ttyS",
+ .write = altera_uart_console_write,
+ .device = uart_console_device,
+ .setup = altera_uart_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &altera_uart_driver,
+};
+
+static int __init altera_uart_console_init(void)
+{
+ register_console(&altera_uart_console);
+ return 0;
+}
+
+console_initcall(altera_uart_console_init);
+
+#define ALTERA_UART_CONSOLE (&altera_uart_console)
+
+#else
+
+#define ALTERA_UART_CONSOLE NULL
+
+#endif /* CONFIG_ALTERA_UART_CONSOLE */
+
+/*
+ * Define the altera_uart UART driver structure.
+ */
+static struct uart_driver altera_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = DRV_NAME,
+ .dev_name = "ttyS",
+ .major = TTY_MAJOR,
+ .minor = 64,
+ .nr = CONFIG_SERIAL_ALTERA_UART_MAXPORTS,
+ .cons = ALTERA_UART_CONSOLE,
+};
+
+static int __devinit altera_uart_probe(struct platform_device *pdev)
+{
+ struct altera_uart_platform_uart *platp = pdev->dev.platform_data;
+ struct uart_port *port;
+ int i;
+
+ for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS && platp[i].mapbase; i++) {
+ port = &altera_uart_ports[i].port;
+
+ port->line = i;
+ port->type = PORT_ALTERA_UART;
+ port->mapbase = platp[i].mapbase;
+ port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
+ port->iotype = SERIAL_IO_MEM;
+ port->irq = platp[i].irq;
+ port->uartclk = platp[i].uartclk;
+ port->ops = &altera_uart_ops;
+ port->flags = ASYNC_BOOT_AUTOCONF;
+
+ uart_add_one_port(&altera_uart_driver, port);
+ }
+
+ return 0;
+}
+
+static int altera_uart_remove(struct platform_device *pdev)
+{
+ struct uart_port *port;
+ int i;
+
+ for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS; i++) {
+ port = &altera_uart_ports[i].port;
+ if (port)
+ uart_remove_one_port(&altera_uart_driver, port);
+ }
+
+ return 0;
+}
+
+static struct platform_driver altera_uart_platform_driver = {
+ .probe = altera_uart_probe,
+ .remove = __devexit_p(altera_uart_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ .pm = NULL,
+ },
+};
+
+static int __init altera_uart_init(void)
+{
+ int rc;
+
+ rc = uart_register_driver(&altera_uart_driver);
+ if (rc)
+ return rc;
+ rc = platform_driver_register(&altera_uart_platform_driver);
+ if (rc) {
+ uart_unregister_driver(&altera_uart_driver);
+ return rc;
+ }
+ return 0;
+}
+
+static void __exit altera_uart_exit(void)
+{
+ platform_driver_unregister(&altera_uart_platform_driver);
+ uart_unregister_driver(&altera_uart_driver);
+}
+
+module_init(altera_uart_init);
+module_exit(altera_uart_exit);
+
+MODULE_DESCRIPTION("Altera UART driver");
+MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
projects / firefly-linux-kernel-4.4.55.git / commitdiff