1 files changed, 608 insertions, 0 deletions

diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
new file mode 100644
index 000000000000..721216292a50
--- /dev/null
+++ b/drivers/tty/serial/altera_uart.c
@@ -0,0 +1,608 @@
+/*
+ * 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/timer.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"
+#define SERIAL_ALTERA_MAJOR 204
+#define SERIAL_ALTERA_MINOR 213
+
+/*
+ * 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;
+        struct timer_list tmr;
+        unsigned int sigs;      /* Local copy of line sigs */
+        unsigned short imr;     /* Local IMR mirror */
+};
+
+static u32 altera_uart_readl(struct uart_port *port, int reg)
+{
+        struct altera_uart_platform_uart *platp = port->private_data;
+
+        return readl(port->membase + (reg << platp->bus_shift));
+}
+
+static void altera_uart_writel(struct uart_port *port, u32 dat, int reg)
+{
+        struct altera_uart_platform_uart *platp = port->private_data;
+
+        writel(dat, port->membase + (reg << platp->bus_shift));
+}
+
+static unsigned int altera_uart_tx_empty(struct uart_port *port)
+{
+        return (altera_uart_readl(port, 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 int sigs;
+
+        sigs = (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+             ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0;
+        sigs |= (pp->sigs & TIOCM_RTS);
+
+        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);
+
+        pp->sigs = sigs;
+        if (sigs & TIOCM_RTS)
+                pp->imr |= ALTERA_UART_CONTROL_RTS_MSK;
+        else
+                pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK;
+        altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
+}
+
+static void altera_uart_start_tx(struct uart_port *port)
+{
+        struct altera_uart *pp = container_of(port, struct altera_uart, port);
+
+        pp->imr |= ALTERA_UART_CONTROL_TRDY_MSK;
+        altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
+}
+
+static void altera_uart_stop_tx(struct uart_port *port)
+{
+        struct altera_uart *pp = container_of(port, struct altera_uart, port);
+
+        pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
+        altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
+}
+
+static void altera_uart_stop_rx(struct uart_port *port)
+{
+        struct altera_uart *pp = container_of(port, struct altera_uart, port);
+
+        pp->imr &= ~ALTERA_UART_CONTROL_RRDY_MSK;
+        altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
+}
+
+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;
+        altera_uart_writel(port, pp->imr, 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);
+        uart_update_timeout(port, termios->c_cflag, baud);
+        altera_uart_writel(port, baudclk, 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 = altera_uart_readl(port, ALTERA_UART_STATUS_REG)) &
+               ALTERA_UART_STATUS_RRDY_MSK) {
+                ch = altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
+                flag = TTY_NORMAL;
+                port->icount.rx++;
+
+                if (status & ALTERA_UART_STATUS_E_MSK) {
+                        altera_uart_writel(port, status,
+                                           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 */
+                altera_uart_writel(port, port->x_char, ALTERA_UART_TXDATA_REG);
+                port->x_char = 0;
+                port->icount.tx++;
+                return;
+        }
+
+        while (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+               ALTERA_UART_STATUS_TRDY_MSK) {
+                if (xmit->head == xmit->tail)
+                        break;
+                altera_uart_writel(port, xmit->buf[xmit->tail],
+                       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;
+                altera_uart_writel(port, pp->imr, 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 = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
+
+        spin_lock(&port->lock);
+        if (isr & ALTERA_UART_STATUS_RRDY_MSK)
+                altera_uart_rx_chars(pp);
+        if (isr & ALTERA_UART_STATUS_TRDY_MSK)
+                altera_uart_tx_chars(pp);
+        spin_unlock(&port->lock);
+
+        return IRQ_RETVAL(isr);
+}
+
+static void altera_uart_timer(unsigned long data)
+{
+        struct uart_port *port = (void *)data;
+        struct altera_uart *pp = container_of(port, struct altera_uart, port);
+
+        altera_uart_interrupt(0, port);
+        mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
+}
+
+static void altera_uart_config_port(struct uart_port *port, int flags)
+{
+        port->type = PORT_ALTERA_UART;
+
+        /* Clear mask, so no surprise interrupts. */
+        altera_uart_writel(port, 0, ALTERA_UART_CONTROL_REG);
+        /* Clear status register */
+        altera_uart_writel(port, 0, 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;
+
+        if (!port->irq) {
+                setup_timer(&pp->tmr, altera_uart_timer, (unsigned long)port);
+                mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
+                return 0;
+        }
+
+        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);
+
+        if (port->irq)
+                free_irq(port->irq, port);
+        else
+                del_timer_sync(&pp->tmr);
+}
+
+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 = UPF_BOOT_AUTOCONF;
+                port->ops = &altera_uart_ops;
+                port->private_data = platp;
+        }
+
+        return 0;
+}
+
+static void altera_uart_console_putc(struct uart_port *port, const char c)
+{
+        while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+                 ALTERA_UART_STATUS_TRDY_MSK))
+                cpu_relax();
+
+        writel(c, port->membase + ALTERA_UART_TXDATA_REG);
+}
+
+static void altera_uart_console_write(struct console *co, const char *s,
+                                      unsigned int count)
+{
+        struct uart_port *port = &(altera_uart_ports + co->index)->port;
+
+        for (; count; count--, s++) {
+                altera_uart_console_putc(port, *s);
+                if (*s == '\n')
+                        altera_uart_console_putc(port, '\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)
+                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   = "ttyAL",
+        .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       = "ttyAL",
+        .major          = SERIAL_ALTERA_MAJOR,
+        .minor          = SERIAL_ALTERA_MINOR,
+        .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;
+        struct resource *res_mem;
+        struct resource *res_irq;
+        int i = pdev->id;
+
+        /* -1 emphasizes that the platform must have one port, no .N suffix */
+        if (i == -1)
+                i = 0;
+
+        if (i >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
+                return -EINVAL;
+
+        port = &altera_uart_ports[i].port;
+
+        res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (res_mem)
+                port->mapbase = res_mem->start;
+        else if (platp->mapbase)
+                port->mapbase = platp->mapbase;
+        else
+                return -EINVAL;
+
+        res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+        if (res_irq)
+                port->irq = res_irq->start;
+        else if (platp->irq)
+                port->irq = platp->irq;
+
+        port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
+        if (!port->membase)
+                return -ENOMEM;
+
+        port->line = i;
+        port->type = PORT_ALTERA_UART;
+        port->iotype = SERIAL_IO_MEM;
+        port->uartclk = platp->uartclk;
+        port->ops = &altera_uart_ops;
+        port->flags = UPF_BOOT_AUTOCONF;
+        port->private_data = platp;
+
+        uart_add_one_port(&altera_uart_driver, port);
+
+        return 0;
+}
+
+static int __devexit altera_uart_remove(struct platform_device *pdev)
+{
+        struct uart_port *port = &altera_uart_ports[pdev->id].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);
+MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_ALTERA_MAJOR);