From: Benjamin Krill <[EMAIL PROTECTED]>

This patch adds support for the nwp serial device which is connected to
a DCR bus. It uses the of_serial device driver to determine necessary
properties from the device tree. The supported device is added as serial
port number 84.

Signed-off-by: Benjamin Krill <[EMAIL PROTECTED]>
Signed-off-by: Arnd Bergmann <[EMAIL PROTECTED]>
---

Since the serial drivers are still orphaned, should we merge this through
the powerpc tree?

---
 drivers/serial/Kconfig      |   11 +-
 drivers/serial/Makefile     |    1 +
 drivers/serial/nwpserial.c  |  443 +++++++++++++++++++++++++++++++++++++++++++
 drivers/serial/of_serial.c  |   18 ++
 include/linux/nwpserial.h   |   18 ++
 include/linux/serial_core.h |    3 +
 6 files changed, 493 insertions(+), 1 deletions(-)
 create mode 100644 drivers/serial/nwpserial.c
 create mode 100644 include/linux/nwpserial.h

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 579d63a..45dcc8d 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -1297,13 +1297,22 @@ config SERIAL_NETX_CONSOLE
 config SERIAL_OF_PLATFORM
        tristate "Serial port on Open Firmware platform bus"
        depends on PPC_OF
-       depends on SERIAL_8250
+       depends on SERIAL_8250 || SERIAL_OF_PLATFORM_NWPSERIAL
        help
          If you have a PowerPC based system that has serial ports
          on a platform specific bus, you should enable this option.
          Currently, only 8250 compatible ports are supported, but
          others can easily be added.
 
+config SERIAL_OF_PLATFORM_NWPSERIAL
+       tristate "NWP serial port driver"
+       depends on PPC_OF && PPC_DCR
+       select SERIAL_OF_PLATFORM
+       select SERIAL_CORE_CONSOLE
+       select SERIAL_CORE
+       help
+         This driver supports the nwp serial port.
+
 config SERIAL_QE
        tristate "Freescale QUICC Engine serial port support"
        depends on QUICC_ENGINE
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 0c17c8d..05da19d 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o
 obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
 obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
+obj-$(CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL) += nwpserial.o
 obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
 obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
 obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
diff --git a/drivers/serial/nwpserial.c b/drivers/serial/nwpserial.c
new file mode 100644
index 0000000..5f2ecab
--- /dev/null
+++ b/drivers/serial/nwpserial.c
@@ -0,0 +1,443 @@
+/*
+ *  Serial Port driver for a NWP uart device
+ *
+ *    Copyright (C) 2008 IBM Corp., Benjamin Krill <[EMAIL PROTECTED]>
+ *
+ *  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/console.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/irqreturn.h>
+#include <linux/mutex.h>
+#include <linux/of_platform.h>
+#include <linux/of_device.h>
+#include <linux/nwpserial.h>
+#include <asm/prom.h>
+#include <asm/dcr.h>
+
+#define NWPSERIAL_NR               2
+
+#define NWPSERIAL_STATUS_RXVALID 0x1
+#define NWPSERIAL_STATUS_TXFULL  0x2
+
+struct nwpserial_port {
+       struct uart_port port;
+       dcr_host_t dcr_host;
+       unsigned int ier;
+       unsigned int mcr;
+};
+
+static DEFINE_MUTEX(nwpserial_mutex);
+static struct nwpserial_port nwpserial_ports[NWPSERIAL_NR];
+
+static void nwpserial_console_putchar(struct uart_port *port, int c)
+{
+       struct nwpserial_port *up = container_of(port, struct nwpserial_port, 
port);
+       /* check if tx buffer is full */
+       while ((dcr_read(up->dcr_host, UART_LSR) & UART_LSR_THRE) == 0)
+               cpu_relax();
+       dcr_write(up->dcr_host, UART_TX, c);
+       up->port.icount.tx++;
+}
+
+static void
+nwpserial_console_write(struct console *co, const char *s, unsigned int count)
+{
+       struct nwpserial_port *up = &nwpserial_ports[co->index];
+       unsigned long flags;
+       int locked = 1;
+
+       if (oops_in_progress)
+               locked = spin_trylock_irqsave(&up->port.lock, flags);
+       else
+               spin_lock_irqsave(&up->port.lock, flags);
+
+       /* save and disable interrupt */
+       up->ier = dcr_read(up->dcr_host, UART_IER);
+       dcr_write(up->dcr_host, UART_IER, up->ier & ~UART_IER_RDI);
+
+       uart_console_write(&up->port, s, count, nwpserial_console_putchar);
+
+       /* wait for transmitter to become emtpy */
+       while ((dcr_read(up->dcr_host, UART_LSR) & UART_LSR_THRE) == 0)
+               cpu_relax();
+
+       /* restore interrupt state */
+       dcr_write(up->dcr_host, UART_IER, up->ier);
+
+       if (locked)
+               spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static struct uart_driver nwpserial_reg;
+static struct console nwpserial_console = {
+       .name           = "ttySQ",
+       .write          = nwpserial_console_write,
+       .device         = uart_console_device,
+       .flags          = CON_PRINTBUFFER,
+       .index          = -1,
+       .data           = &nwpserial_reg,
+};
+
+/*******************************************************************************/
+
+static int nwpserial_request_port(struct uart_port *port)
+{
+       return 0;
+}
+
+static void nwpserial_release_port(struct uart_port *port)
+{
+       /* N/A */
+}
+
+static void nwpserial_config_port(struct uart_port *port, int flags)
+{
+       port->type = PORT_NWPSERIAL;
+}
+
+static irqreturn_t nwpserial_interrupt(int irq, void *dev_id)
+{
+       struct nwpserial_port *up = dev_id;//container_of(dev_id, struct 
nwpserial_port, port);
+       struct tty_struct *tty = up->port.info->port.tty;
+       irqreturn_t ret;
+       unsigned int iir;
+       unsigned char ch;
+
+       spin_lock(&up->port.lock);
+
+       /* check if the uart was the interrupt source. */
+       iir = dcr_read(up->dcr_host, UART_IIR);
+       if (!iir) {
+               ret = IRQ_NONE;
+               goto out;
+       }
+
+       do {
+               up->port.icount.rx++;
+               ch = dcr_read(up->dcr_host, UART_RX);
+               if (up->port.ignore_status_mask != NWPSERIAL_STATUS_RXVALID)
+                       tty_insert_flip_char(tty, ch, TTY_NORMAL);
+       } while (dcr_read(up->dcr_host, UART_RX) & UART_LSR_DR);
+
+       tty_flip_buffer_push(tty);
+       ret = IRQ_HANDLED;
+
+out:
+       spin_unlock(&up->port.lock);
+       return ret;
+}
+
+static int nwpserial_startup(struct uart_port *port)
+{
+       struct nwpserial_port *up = container_of(port, struct nwpserial_port, 
port);
+       int err;
+
+       /* disable flow control by default */
+       up->mcr = dcr_read(up->dcr_host, UART_MCR) & ~UART_MCR_AFE;
+       dcr_write(up->dcr_host, UART_MCR, up->mcr);
+
+       /* register interrupt handler */
+       err = request_irq(up->port.irq, nwpserial_interrupt,
+                               IRQF_SHARED, "nwpserial", up);
+       if (err) {
+               free_irq(up->port.irq, port);
+               return err;
+       }
+
+       /* enable interrupts */
+       up->ier = UART_IER_RDI;
+       dcr_write(up->dcr_host, UART_IER, up->ier);
+
+       /* enable receiving */
+       up->port.ignore_status_mask &= ~NWPSERIAL_STATUS_RXVALID;
+
+       return 0;
+}
+
+static void nwpserial_shutdown(struct uart_port *port)
+{
+       struct nwpserial_port *up = container_of(port, struct nwpserial_port, 
port);
+
+       /* disable receiving */
+       up->port.ignore_status_mask |= NWPSERIAL_STATUS_RXVALID;
+
+       /* disable interrupts from this port */
+       up->ier = 0;
+       dcr_write(up->dcr_host, UART_IER, up->ier);
+
+       /* free irq */
+       free_irq(up->port.irq, port);
+}
+
+static int nwpserial_verify_port(struct uart_port *port, struct serial_struct 
*ser)
+{
+       return -EINVAL;
+}
+
+static const char *nwpserial_type(struct uart_port *port)
+{
+       return port->type == PORT_NWPSERIAL ? "nwpserial" : NULL;
+}
+
+static void nwpserial_set_termios(struct uart_port *port, struct ktermios 
*termios,
+                                struct ktermios *old)
+{
+       struct nwpserial_port *up = container_of(port, struct nwpserial_port, 
port);
+
+       up->port.read_status_mask = NWPSERIAL_STATUS_RXVALID | 
NWPSERIAL_STATUS_TXFULL;
+
+       up->port.ignore_status_mask = 0;
+       /* ignore all characters if CREAD is not set */
+       if ((termios->c_cflag & CREAD) == 0)
+               up->port.ignore_status_mask |= NWPSERIAL_STATUS_RXVALID;
+}
+
+static void nwpserial_break_ctl(struct uart_port *port, int ctl)
+{
+       /* N/A */
+}
+
+static void nwpserial_enable_ms(struct uart_port *port)
+{
+       /* N/A */
+}
+
+static void nwpserial_stop_rx(struct uart_port *port)
+{
+       struct nwpserial_port *up = container_of(port, struct nwpserial_port, 
port);
+       /* don't forward any more data (like !CREAD) */
+       up->port.ignore_status_mask = NWPSERIAL_STATUS_RXVALID;
+}
+
+static void nwpserial_putchar(struct nwpserial_port *up, unsigned char c)
+{
+       /* check if tx buffer is full */
+       while ((dcr_read(up->dcr_host, UART_LSR) & UART_LSR_THRE) == 0)
+               cpu_relax();
+       dcr_write(up->dcr_host, UART_TX, c);
+       up->port.icount.tx++;
+}
+
+static void nwpserial_start_tx(struct uart_port *port)
+{
+       struct nwpserial_port *up = container_of(port, struct nwpserial_port, 
port);
+       struct circ_buf *xmit  = &up->port.info->xmit;
+
+       if (port->x_char) {
+               nwpserial_putchar(up, up->port.x_char);
+               port->x_char = 0;
+       }
+
+       while (!(uart_circ_empty(xmit) || uart_tx_stopped(&up->port))) {
+               nwpserial_putchar(up, xmit->buf[xmit->tail]);
+               xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
+       }
+}
+
+static unsigned int nwpserial_get_mctrl(struct uart_port *port)
+{
+       return 0;
+}
+
+static void nwpserial_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+       /* N/A */
+}
+
+static void nwpserial_stop_tx(struct uart_port *port)
+{
+       /* N/A */
+}
+
+static unsigned int nwpserial_tx_empty(struct uart_port *port)
+{
+       struct nwpserial_port *up = container_of(port, struct nwpserial_port, 
port);
+       unsigned long flags;
+       int ret;
+
+       spin_lock_irqsave(&up->port.lock, flags);
+       ret = dcr_read(up->dcr_host, UART_LSR);
+       spin_unlock_irqrestore(&up->port.lock, flags);
+
+       return ret & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
+}
+
+static struct uart_ops nwpserial_pops = {
+       .tx_empty     = nwpserial_tx_empty,
+       .set_mctrl    = nwpserial_set_mctrl,
+       .get_mctrl    = nwpserial_get_mctrl,
+       .stop_tx      = nwpserial_stop_tx,
+       .start_tx     = nwpserial_start_tx,
+       .stop_rx      = nwpserial_stop_rx,
+       .enable_ms    = nwpserial_enable_ms,
+       .break_ctl    = nwpserial_break_ctl,
+       .startup      = nwpserial_startup,
+       .shutdown     = nwpserial_shutdown,
+       .set_termios  = nwpserial_set_termios,
+       .type         = nwpserial_type,
+       .release_port = nwpserial_release_port,
+       .request_port = nwpserial_request_port,
+       .config_port  = nwpserial_config_port,
+       .verify_port  = nwpserial_verify_port,
+};
+
+static struct uart_driver nwpserial_reg = {
+       .owner       = THIS_MODULE,
+       .driver_name = "nwpserial",
+       .dev_name    = "ttySQ",
+       .major       = TTY_MAJOR,
+       .minor       = 68,
+       .nr          = NWPSERIAL_NR,
+       .cons        = &nwpserial_console,
+};
+
+int
+nwpserial_register_port(struct uart_port *port)
+{
+       struct nwpserial_port *up = NULL;
+       int ret = -1;
+       int i;
+       static int first = 1;
+       int dcr_len;
+       int dcr_base;
+       struct device_node *dn;
+
+       mutex_lock(&nwpserial_mutex);
+
+       dn = to_of_device(port->dev)->node;
+       if (dn == NULL)
+               goto out;
+
+       /* get dcr base. */
+       dcr_base = dcr_resource_start(dn, 0);
+
+       /* find matching entry */
+       for (i = 0; i < NWPSERIAL_NR; i++)
+               if (nwpserial_ports[i].port.iobase == dcr_base) {
+                       up = &nwpserial_ports[i];
+                       break;
+               }
+
+       /* we didn't find a mtching entry, search for a free port */
+       if (up == NULL)
+               for (i = 0; i < NWPSERIAL_NR; i++)
+                       if (nwpserial_ports[i].port.type == PORT_UNKNOWN &&
+                               nwpserial_ports[i].port.iobase == 0) {
+                               up = &nwpserial_ports[i];
+                               break;
+                       }
+
+       if (up == NULL) {
+               ret = -EBUSY;
+               goto out;
+       }
+
+       if (first)
+               uart_register_driver(&nwpserial_reg);
+       first = 0;
+
+       up->port.membase      = port->membase;
+       up->port.irq          = port->irq;
+       up->port.uartclk      = port->uartclk;
+       up->port.fifosize     = port->fifosize;
+       up->port.regshift     = port->regshift;
+       up->port.iotype       = port->iotype;
+       up->port.flags        = port->flags;
+       up->port.mapbase      = port->mapbase;
+       up->port.private_data = port->private_data;
+
+       if (port->dev)
+               up->port.dev = port->dev;
+
+       if (up->port.iobase != dcr_base) {
+               up->port.ops          = &nwpserial_pops;
+               up->port.fifosize     = 16;
+
+               spin_lock_init(&up->port.lock);
+
+               up->port.iobase = dcr_base;
+               dcr_len = dcr_resource_len(dn, 0);
+
+               up->dcr_host = dcr_map(dn, dcr_base, dcr_len);
+               if (!DCR_MAP_OK(up->dcr_host)) {
+                       printk("Cannot map DCR resources for NWPSERIAL");
+                       goto out;
+               }
+       }
+
+       ret = uart_add_one_port(&nwpserial_reg, &up->port);
+       if (ret == 0)
+               ret = up->port.line;
+
+out:
+       mutex_unlock(&nwpserial_mutex);
+
+       return ret;
+}
+EXPORT_SYMBOL(nwpserial_register_port);
+
+void nwpserial_unregister_port(int line)
+{
+       struct nwpserial_port *up = &nwpserial_ports[line];
+       mutex_lock(&nwpserial_mutex);
+       uart_remove_one_port(&nwpserial_reg, &up->port);
+
+       up->port.type = PORT_UNKNOWN;
+
+       mutex_unlock(&nwpserial_mutex);
+}
+EXPORT_SYMBOL(nwpserial_unregister_port);
+
+static int __init nwpserial_console_init(void)
+{
+       struct nwpserial_port *up = NULL;
+       struct device_node *dn;
+       const char *name;
+       int dcr_base;
+       int dcr_len;
+       int i;
+
+       /* search for a free port */
+       for (i = 0; i < NWPSERIAL_NR; i++)
+               if (nwpserial_ports[i].port.type == PORT_UNKNOWN) {
+                       up = &nwpserial_ports[i];
+                       break;
+               }
+
+       if (up == NULL)
+               return -1;
+
+       name = of_get_property(of_chosen, "linux,stdout-path", NULL);
+       if (name == NULL)
+               return -1;
+
+       dn = of_find_node_by_path(name);
+       if (!dn)
+               return -1;
+
+       spin_lock_init(&up->port.lock);
+       up->port.ops = &nwpserial_pops;
+       up->port.type = PORT_NWPSERIAL;
+       up->port.fifosize = 16;
+
+       dcr_base = dcr_resource_start(dn, 0);
+       dcr_len = dcr_resource_len(dn, 0);
+       up->port.iobase = dcr_base;
+
+       up->dcr_host = dcr_map(dn, dcr_base, dcr_len);
+       if (!DCR_MAP_OK(up->dcr_host)) {
+               printk("Cannot map DCR resources for SERIAL");
+               return -1;
+       }
+       register_console(&nwpserial_console);
+       return 0;
+}
+console_initcall(nwpserial_console_init);
diff --git a/drivers/serial/of_serial.c b/drivers/serial/of_serial.c
index 8fa0ff5..bb56231 100644
--- a/drivers/serial/of_serial.c
+++ b/drivers/serial/of_serial.c
@@ -14,6 +14,7 @@
 #include <linux/serial_core.h>
 #include <linux/serial_8250.h>
 #include <linux/of_platform.h>
+#include <linux/nwpserial.h>
 
 #include <asm/prom.h>
 
@@ -99,9 +100,16 @@ static int __devinit of_platform_serial_probe(struct 
of_device *ofdev,
                goto out;
 
        switch (port_type) {
+#ifdef CONFIG_SERIAL_8250
        case PORT_8250 ... PORT_MAX_8250:
                ret = serial8250_register_port(&port);
                break;
+#endif
+#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
+       case PORT_NWPSERIAL:
+               ret = nwpserial_register_port(&port);
+               break;
+#endif
        default:
                /* need to add code for these */
        case PORT_UNKNOWN:
@@ -129,9 +137,16 @@ static int of_platform_serial_remove(struct of_device 
*ofdev)
 {
        struct of_serial_info *info = ofdev->dev.driver_data;
        switch (info->type) {
+#ifdef CONFIG_SERIAL_8250
        case PORT_8250 ... PORT_MAX_8250:
                serial8250_unregister_port(info->line);
                break;
+#endif
+#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
+       case PORT_NWPSERIAL:
+               nwpserial_unregister_port(info->line);
+               break;
+#endif
        default:
                /* need to add code for these */
                break;
@@ -148,6 +163,9 @@ static struct of_device_id __devinitdata 
of_platform_serial_table[] = {
        { .type = "serial", .compatible = "ns16450",  .data = (void 
*)PORT_16450, },
        { .type = "serial", .compatible = "ns16550",  .data = (void 
*)PORT_16550, },
        { .type = "serial", .compatible = "ns16750",  .data = (void 
*)PORT_16750, },
+#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
+       { .type = "serial", .compatible = "ibm,qpace-nwpserial",  .data = (void 
*)PORT_NWPSERIAL, },
+#endif
        { .type = "serial",                           .data = (void 
*)PORT_UNKNOWN, },
        { /* end of list */ },
 };
diff --git a/include/linux/nwpserial.h b/include/linux/nwpserial.h
new file mode 100644
index 0000000..9acb215
--- /dev/null
+++ b/include/linux/nwpserial.h
@@ -0,0 +1,18 @@
+/*
+ *  Serial Port driver for a NWP uart device
+ *
+ *    Copyright (C) 2008 IBM Corp., Benjamin Krill <[EMAIL PROTECTED]>
+ *
+ *  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.
+ *
+ */
+#ifndef _NWPSERIAL_H
+#define _NWPSERIAL_H
+
+int nwpserial_register_port(struct uart_port *port);
+void nwpserial_unregister_port(int line);
+
+#endif /* _NWPSERIAL_H */
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 4e4f127..4621faf 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -158,6 +158,9 @@
 /* SH-SCI */
 #define PORT_SCIFA     83
 
+/* NWPSERIAL */
+#define PORT_NWPSERIAL 84
+
 #ifdef __KERNEL__
 
 #include <linux/compiler.h>
-- 
1.5.6.5


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