1 files changed, 709 insertions, 0 deletions

diff --git a/drivers/tty/serial/apbuart.c b/drivers/tty/serial/apbuart.c
new file mode 100644
index 000000000000..095a5d562618
--- /dev/null
+++ b/drivers/tty/serial/apbuart.c
@@ -0,0 +1,709 @@
+/*
+ *  Driver for GRLIB serial ports (APBUART)
+ *
+ *  Based on linux/drivers/serial/amba.c
+ *
+ *  Copyright (C) 2000 Deep Blue Solutions Ltd.
+ *  Copyright (C) 2003 Konrad Eisele <eiselekd@web.de>
+ *  Copyright (C) 2006 Daniel Hellstrom <daniel@gaisler.com>, Aeroflex Gaisler AB
+ *  Copyright (C) 2008 Gilead Kutnick <kutnickg@zin-tech.com>
+ *  Copyright (C) 2009 Kristoffer Glembo <kristoffer@gaisler.com>, Aeroflex Gaisler AB
+ */
+
+#if defined(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/kthread.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/serial_core.h>
+#include <asm/irq.h>
+
+#include "apbuart.h"
+
+#define SERIAL_APBUART_MAJOR    TTY_MAJOR
+#define SERIAL_APBUART_MINOR    64
+#define UART_DUMMY_RSR_RX       0x8000  /* for ignore all read */
+
+static void apbuart_tx_chars(struct uart_port *port);
+
+static void apbuart_stop_tx(struct uart_port *port)
+{
+        unsigned int cr;
+
+        cr = UART_GET_CTRL(port);
+        cr &= ~UART_CTRL_TI;
+        UART_PUT_CTRL(port, cr);
+}
+
+static void apbuart_start_tx(struct uart_port *port)
+{
+        unsigned int cr;
+
+        cr = UART_GET_CTRL(port);
+        cr |= UART_CTRL_TI;
+        UART_PUT_CTRL(port, cr);
+
+        if (UART_GET_STATUS(port) & UART_STATUS_THE)
+                apbuart_tx_chars(port);
+}
+
+static void apbuart_stop_rx(struct uart_port *port)
+{
+        unsigned int cr;
+
+        cr = UART_GET_CTRL(port);
+        cr &= ~(UART_CTRL_RI);
+        UART_PUT_CTRL(port, cr);
+}
+
+static void apbuart_enable_ms(struct uart_port *port)
+{
+        /* No modem status change interrupts for APBUART */
+}
+
+static void apbuart_rx_chars(struct uart_port *port)
+{
+        struct tty_struct *tty = port->state->port.tty;
+        unsigned int status, ch, rsr, flag;
+        unsigned int max_chars = port->fifosize;
+
+        status = UART_GET_STATUS(port);
+
+        while (UART_RX_DATA(status) && (max_chars--)) {
+
+                ch = UART_GET_CHAR(port);
+                flag = TTY_NORMAL;
+
+                port->icount.rx++;
+
+                rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
+                UART_PUT_STATUS(port, 0);
+                if (rsr & UART_STATUS_ERR) {
+
+                        if (rsr & UART_STATUS_BR) {
+                                rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
+                                port->icount.brk++;
+                                if (uart_handle_break(port))
+                                        goto ignore_char;
+                        } else if (rsr & UART_STATUS_PE) {
+                                port->icount.parity++;
+                        } else if (rsr & UART_STATUS_FE) {
+                                port->icount.frame++;
+                        }
+                        if (rsr & UART_STATUS_OE)
+                                port->icount.overrun++;
+
+                        rsr &= port->read_status_mask;
+
+                        if (rsr & UART_STATUS_PE)
+                                flag = TTY_PARITY;
+                        else if (rsr & UART_STATUS_FE)
+                                flag = TTY_FRAME;
+                }
+
+                if (uart_handle_sysrq_char(port, ch))
+                        goto ignore_char;
+
+                uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
+
+
+              ignore_char:
+                status = UART_GET_STATUS(port);
+        }
+
+        tty_flip_buffer_push(tty);
+}
+
+static void apbuart_tx_chars(struct uart_port *port)
+{
+        struct circ_buf *xmit = &port->state->xmit;
+        int count;
+
+        if (port->x_char) {
+                UART_PUT_CHAR(port, port->x_char);
+                port->icount.tx++;
+                port->x_char = 0;
+                return;
+        }
+
+        if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+                apbuart_stop_tx(port);
+                return;
+        }
+
+        /* amba: fill FIFO */
+        count = port->fifosize >> 1;
+        do {
+                UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
+                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+                port->icount.tx++;
+                if (uart_circ_empty(xmit))
+                        break;
+        } while (--count > 0);
+
+        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+                uart_write_wakeup(port);
+
+        if (uart_circ_empty(xmit))
+                apbuart_stop_tx(port);
+}
+
+static irqreturn_t apbuart_int(int irq, void *dev_id)
+{
+        struct uart_port *port = dev_id;
+        unsigned int status;
+
+        spin_lock(&port->lock);
+
+        status = UART_GET_STATUS(port);
+        if (status & UART_STATUS_DR)
+                apbuart_rx_chars(port);
+        if (status & UART_STATUS_THE)
+                apbuart_tx_chars(port);
+
+        spin_unlock(&port->lock);
+
+        return IRQ_HANDLED;
+}
+
+static unsigned int apbuart_tx_empty(struct uart_port *port)
+{
+        unsigned int status = UART_GET_STATUS(port);
+        return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int apbuart_get_mctrl(struct uart_port *port)
+{
+        /* The GRLIB APBUART handles flow control in hardware */
+        return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+        /* The GRLIB APBUART handles flow control in hardware */
+}
+
+static void apbuart_break_ctl(struct uart_port *port, int break_state)
+{
+        /* We don't support sending break */
+}
+
+static int apbuart_startup(struct uart_port *port)
+{
+        int retval;
+        unsigned int cr;
+
+        /* Allocate the IRQ */
+        retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
+        if (retval)
+                return retval;
+
+        /* Finally, enable interrupts */
+        cr = UART_GET_CTRL(port);
+        UART_PUT_CTRL(port,
+                      cr | UART_CTRL_RE | UART_CTRL_TE |
+                      UART_CTRL_RI | UART_CTRL_TI);
+
+        return 0;
+}
+
+static void apbuart_shutdown(struct uart_port *port)
+{
+        unsigned int cr;
+
+        /* disable all interrupts, disable the port */
+        cr = UART_GET_CTRL(port);
+        UART_PUT_CTRL(port,
+                      cr & ~(UART_CTRL_RE | UART_CTRL_TE |
+                             UART_CTRL_RI | UART_CTRL_TI));
+
+        /* Free the interrupt */
+        free_irq(port->irq, port);
+}
+
+static void apbuart_set_termios(struct uart_port *port,
+                                struct ktermios *termios, struct ktermios *old)
+{
+        unsigned int cr;
+        unsigned long flags;
+        unsigned int baud, quot;
+
+        /* Ask the core to calculate the divisor for us. */
+        baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+        if (baud == 0)
+                panic("invalid baudrate %i\n", port->uartclk / 16);
+
+        /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
+        quot = (uart_get_divisor(port, baud)) * 2;
+        cr = UART_GET_CTRL(port);
+        cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
+
+        if (termios->c_cflag & PARENB) {
+                cr |= UART_CTRL_PE;
+                if ((termios->c_cflag & PARODD))
+                        cr |= UART_CTRL_PS;
+        }
+
+        /* Enable flow control. */
+        if (termios->c_cflag & CRTSCTS)
+                cr |= UART_CTRL_FL;
+
+        spin_lock_irqsave(&port->lock, flags);
+
+        /* Update the per-port timeout. */
+        uart_update_timeout(port, termios->c_cflag, baud);
+
+        port->read_status_mask = UART_STATUS_OE;
+        if (termios->c_iflag & INPCK)
+                port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
+
+        /* Characters to ignore */
+        port->ignore_status_mask = 0;
+        if (termios->c_iflag & IGNPAR)
+                port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
+
+        /* Ignore all characters if CREAD is not set. */
+        if ((termios->c_cflag & CREAD) == 0)
+                port->ignore_status_mask |= UART_DUMMY_RSR_RX;
+
+        /* Set baud rate */
+        quot -= 1;
+        UART_PUT_SCAL(port, quot);
+        UART_PUT_CTRL(port, cr);
+
+        spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *apbuart_type(struct uart_port *port)
+{
+        return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
+}
+
+static void apbuart_release_port(struct uart_port *port)
+{
+        release_mem_region(port->mapbase, 0x100);
+}
+
+static int apbuart_request_port(struct uart_port *port)
+{
+        return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
+            != NULL ? 0 : -EBUSY;
+        return 0;
+}
+
+/* Configure/autoconfigure the port */
+static void apbuart_config_port(struct uart_port *port, int flags)
+{
+        if (flags & UART_CONFIG_TYPE) {
+                port->type = PORT_APBUART;
+                apbuart_request_port(port);
+        }
+}
+
+/* Verify the new serial_struct (for TIOCSSERIAL) */
+static int apbuart_verify_port(struct uart_port *port,
+                               struct serial_struct *ser)
+{
+        int ret = 0;
+        if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
+                ret = -EINVAL;
+        if (ser->irq < 0 || ser->irq >= NR_IRQS)
+                ret = -EINVAL;
+        if (ser->baud_base < 9600)
+                ret = -EINVAL;
+        return ret;
+}
+
+static struct uart_ops grlib_apbuart_ops = {
+        .tx_empty = apbuart_tx_empty,
+        .set_mctrl = apbuart_set_mctrl,
+        .get_mctrl = apbuart_get_mctrl,
+        .stop_tx = apbuart_stop_tx,
+        .start_tx = apbuart_start_tx,
+        .stop_rx = apbuart_stop_rx,
+        .enable_ms = apbuart_enable_ms,
+        .break_ctl = apbuart_break_ctl,
+        .startup = apbuart_startup,
+        .shutdown = apbuart_shutdown,
+        .set_termios = apbuart_set_termios,
+        .type = apbuart_type,
+        .release_port = apbuart_release_port,
+        .request_port = apbuart_request_port,
+        .config_port = apbuart_config_port,
+        .verify_port = apbuart_verify_port,
+};
+
+static struct uart_port grlib_apbuart_ports[UART_NR];
+static struct device_node *grlib_apbuart_nodes[UART_NR];
+
+static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
+{
+        int ctrl, loop = 0;
+        int status;
+        int fifosize;
+        unsigned long flags;
+
+        ctrl = UART_GET_CTRL(port);
+
+        /*
+         * Enable the transceiver and wait for it to be ready to send data.
+         * Clear interrupts so that this process will not be externally
+         * interrupted in the middle (which can cause the transceiver to
+         * drain prematurely).
+         */
+
+        local_irq_save(flags);
+
+        UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
+
+        while (!UART_TX_READY(UART_GET_STATUS(port)))
+                loop++;
+
+        /*
+         * Disable the transceiver so data isn't actually sent during the
+         * actual test.
+         */
+
+        UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
+
+        fifosize = 1;
+        UART_PUT_CHAR(port, 0);
+
+        /*
+         * So long as transmitting a character increments the tranceivier FIFO
+         * length the FIFO must be at least that big. These bytes will
+         * automatically drain off of the FIFO.
+         */
+
+        status = UART_GET_STATUS(port);
+        while (((status >> 20) & 0x3F) == fifosize) {
+                fifosize++;
+                UART_PUT_CHAR(port, 0);
+                status = UART_GET_STATUS(port);
+        }
+
+        fifosize--;
+
+        UART_PUT_CTRL(port, ctrl);
+        local_irq_restore(flags);
+
+        if (fifosize == 0)
+                fifosize = 1;
+
+        return fifosize;
+}
+
+static void apbuart_flush_fifo(struct uart_port *port)
+{
+        int i;
+
+        for (i = 0; i < port->fifosize; i++)
+                UART_GET_CHAR(port);
+}
+
+
+/* ======================================================================== */
+/* Console driver, if enabled                                               */
+/* ======================================================================== */
+
+#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
+
+static void apbuart_console_putchar(struct uart_port *port, int ch)
+{
+        unsigned int status;
+        do {
+                status = UART_GET_STATUS(port);
+        } while (!UART_TX_READY(status));
+        UART_PUT_CHAR(port, ch);
+}
+
+static void
+apbuart_console_write(struct console *co, const char *s, unsigned int count)
+{
+        struct uart_port *port = &grlib_apbuart_ports[co->index];
+        unsigned int status, old_cr, new_cr;
+
+        /* First save the CR then disable the interrupts */
+        old_cr = UART_GET_CTRL(port);
+        new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
+        UART_PUT_CTRL(port, new_cr);
+
+        uart_console_write(port, s, count, apbuart_console_putchar);
+
+        /*
+         *      Finally, wait for transmitter to become empty
+         *      and restore the TCR
+         */
+        do {
+                status = UART_GET_STATUS(port);
+        } while (!UART_TX_READY(status));
+        UART_PUT_CTRL(port, old_cr);
+}
+
+static void __init
+apbuart_console_get_options(struct uart_port *port, int *baud,
+                            int *parity, int *bits)
+{
+        if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
+
+                unsigned int quot, status;
+                status = UART_GET_STATUS(port);
+
+                *parity = 'n';
+                if (status & UART_CTRL_PE) {
+                        if ((status & UART_CTRL_PS) == 0)
+                                *parity = 'e';
+                        else
+                                *parity = 'o';
+                }
+
+                *bits = 8;
+                quot = UART_GET_SCAL(port) / 8;
+                *baud = port->uartclk / (16 * (quot + 1));
+        }
+}
+
+static int __init apbuart_console_setup(struct console *co, char *options)
+{
+        struct uart_port *port;
+        int baud = 38400;
+        int bits = 8;
+        int parity = 'n';
+        int flow = 'n';
+
+        pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
+                 co, co->index, options);
+
+        /*
+         * Check whether an invalid uart number has been specified, and
+         * if so, search for the first available port that does have
+         * console support.
+         */
+        if (co->index >= grlib_apbuart_port_nr)
+                co->index = 0;
+
+        port = &grlib_apbuart_ports[co->index];
+
+        spin_lock_init(&port->lock);
+
+        if (options)
+                uart_parse_options(options, &baud, &parity, &bits, &flow);
+        else
+                apbuart_console_get_options(port, &baud, &parity, &bits);
+
+        return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver grlib_apbuart_driver;
+
+static struct console grlib_apbuart_console = {
+        .name = "ttyS",
+        .write = apbuart_console_write,
+        .device = uart_console_device,
+        .setup = apbuart_console_setup,
+        .flags = CON_PRINTBUFFER,
+        .index = -1,
+        .data = &grlib_apbuart_driver,
+};
+
+
+static int grlib_apbuart_configure(void);
+
+static int __init apbuart_console_init(void)
+{
+        if (grlib_apbuart_configure())
+                return -ENODEV;
+        register_console(&grlib_apbuart_console);
+        return 0;
+}
+
+console_initcall(apbuart_console_init);
+
+#define APBUART_CONSOLE (&grlib_apbuart_console)
+#else
+#define APBUART_CONSOLE NULL
+#endif
+
+static struct uart_driver grlib_apbuart_driver = {
+        .owner = THIS_MODULE,
+        .driver_name = "serial",
+        .dev_name = "ttyS",
+        .major = SERIAL_APBUART_MAJOR,
+        .minor = SERIAL_APBUART_MINOR,
+        .nr = UART_NR,
+        .cons = APBUART_CONSOLE,
+};
+
+
+/* ======================================================================== */
+/* OF Platform Driver                                                       */
+/* ======================================================================== */
+
+static int __devinit apbuart_probe(struct platform_device *op,
+                                   const struct of_device_id *match)
+{
+        int i = -1;
+        struct uart_port *port = NULL;
+
+        i = 0;
+        for (i = 0; i < grlib_apbuart_port_nr; i++) {
+                if (op->dev.of_node == grlib_apbuart_nodes[i])
+                        break;
+        }
+
+        port = &grlib_apbuart_ports[i];
+        port->dev = &op->dev;
+
+        uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
+
+        apbuart_flush_fifo((struct uart_port *) port);
+
+        printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
+               (unsigned long long) port->mapbase, port->irq);
+        return 0;
+}
+
+static struct of_device_id __initdata apbuart_match[] = {
+        {
+         .name = "GAISLER_APBUART",
+         },
+        {
+         .name = "01_00c",
+         },
+        {},
+};
+
+static struct of_platform_driver grlib_apbuart_of_driver = {
+        .probe = apbuart_probe,
+        .driver = {
+                .owner = THIS_MODULE,
+                .name = "grlib-apbuart",
+                .of_match_table = apbuart_match,
+        },
+};
+
+
+static int grlib_apbuart_configure(void)
+{
+        struct device_node *np, *rp;
+        const u32 *prop;
+        int freq_khz, line = 0;
+
+        /* Get bus frequency */
+        rp = of_find_node_by_path("/");
+        if (!rp)
+                return -ENODEV;
+        rp = of_get_next_child(rp, NULL);
+        if (!rp)
+                return -ENODEV;
+        prop = of_get_property(rp, "clock-frequency", NULL);
+        if (!prop)
+                return -ENODEV;
+        freq_khz = *prop;
+
+        for_each_matching_node(np, apbuart_match) {
+                const int *irqs, *ampopts;
+                const struct amba_prom_registers *regs;
+                struct uart_port *port;
+                unsigned long addr;
+
+                ampopts = of_get_property(np, "ampopts", NULL);
+                if (ampopts && (*ampopts == 0))
+                        continue; /* Ignore if used by another OS instance */
+
+                irqs = of_get_property(np, "interrupts", NULL);
+                regs = of_get_property(np, "reg", NULL);
+
+                if (!irqs || !regs)
+                        continue;
+
+                grlib_apbuart_nodes[line] = np;
+
+                addr = regs->phys_addr;
+
+                port = &grlib_apbuart_ports[line];
+
+                port->mapbase = addr;
+                port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
+                port->irq = *irqs;
+                port->iotype = UPIO_MEM;
+                port->ops = &grlib_apbuart_ops;
+                port->flags = UPF_BOOT_AUTOCONF;
+                port->line = line;
+                port->uartclk = freq_khz * 1000;
+                port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
+                line++;
+
+                /* We support maximum UART_NR uarts ... */
+                if (line == UART_NR)
+                        break;
+        }
+
+        grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
+        return line ? 0 : -ENODEV;
+}
+
+static int __init grlib_apbuart_init(void)
+{
+        int ret;
+
+        /* Find all APBUARTS in device the tree and initialize their ports */
+        ret = grlib_apbuart_configure();
+        if (ret)
+                return ret;
+
+        printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
+
+        ret = uart_register_driver(&grlib_apbuart_driver);
+
+        if (ret) {
+                printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
+                       __FILE__, ret);
+                return ret;
+        }
+
+        ret = of_register_platform_driver(&grlib_apbuart_of_driver);
+        if (ret) {
+                printk(KERN_ERR
+                       "%s: of_register_platform_driver failed (%i)\n",
+                       __FILE__, ret);
+                uart_unregister_driver(&grlib_apbuart_driver);
+                return ret;
+        }
+
+        return ret;
+}
+
+static void __exit grlib_apbuart_exit(void)
+{
+        int i;
+
+        for (i = 0; i < grlib_apbuart_port_nr; i++)
+                uart_remove_one_port(&grlib_apbuart_driver,
+                                     &grlib_apbuart_ports[i]);
+
+        uart_unregister_driver(&grlib_apbuart_driver);
+        of_unregister_platform_driver(&grlib_apbuart_of_driver);
+}
+
+module_init(grlib_apbuart_init);
+module_exit(grlib_apbuart_exit);
+
+MODULE_AUTHOR("Aeroflex Gaisler AB");
+MODULE_DESCRIPTION("GRLIB APBUART serial driver");
+MODULE_VERSION("2.1");
+MODULE_LICENSE("GPL");