linux/drivers/tty/serial/timbuart.c
Linus Torvalds e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00

517 lines
13 KiB
C

/*
* timbuart.c timberdale FPGA UART driver
* Copyright (c) 2009 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* Supports:
* Timberdale FPGA UART
*/
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/serial_core.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/module.h>
#include "timbuart.h"
struct timbuart_port {
struct uart_port port;
struct tasklet_struct tasklet;
int usedma;
u32 last_ier;
struct platform_device *dev;
};
static int baudrates[] = {9600, 19200, 38400, 57600, 115200, 230400, 460800,
921600, 1843200, 3250000};
static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier);
static irqreturn_t timbuart_handleinterrupt(int irq, void *devid);
static void timbuart_stop_rx(struct uart_port *port)
{
/* spin lock held by upper layer, disable all RX interrupts */
u32 ier = ioread32(port->membase + TIMBUART_IER) & ~RXFLAGS;
iowrite32(ier, port->membase + TIMBUART_IER);
}
static void timbuart_stop_tx(struct uart_port *port)
{
/* spinlock held by upper layer, disable TX interrupt */
u32 ier = ioread32(port->membase + TIMBUART_IER) & ~TXBAE;
iowrite32(ier, port->membase + TIMBUART_IER);
}
static void timbuart_start_tx(struct uart_port *port)
{
struct timbuart_port *uart =
container_of(port, struct timbuart_port, port);
/* do not transfer anything here -> fire off the tasklet */
tasklet_schedule(&uart->tasklet);
}
static unsigned int timbuart_tx_empty(struct uart_port *port)
{
u32 isr = ioread32(port->membase + TIMBUART_ISR);
return (isr & TXBE) ? TIOCSER_TEMT : 0;
}
static void timbuart_flush_buffer(struct uart_port *port)
{
if (!timbuart_tx_empty(port)) {
u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
TIMBUART_CTRL_FLSHTX;
iowrite8(ctl, port->membase + TIMBUART_CTRL);
iowrite32(TXBF, port->membase + TIMBUART_ISR);
}
}
static void timbuart_rx_chars(struct uart_port *port)
{
struct tty_port *tport = &port->state->port;
while (ioread32(port->membase + TIMBUART_ISR) & RXDP) {
u8 ch = ioread8(port->membase + TIMBUART_RXFIFO);
port->icount.rx++;
tty_insert_flip_char(tport, ch, TTY_NORMAL);
}
spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
spin_lock(&port->lock);
dev_dbg(port->dev, "%s - total read %d bytes\n",
__func__, port->icount.rx);
}
static void timbuart_tx_chars(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
while (!(ioread32(port->membase + TIMBUART_ISR) & TXBF) &&
!uart_circ_empty(xmit)) {
iowrite8(xmit->buf[xmit->tail],
port->membase + TIMBUART_TXFIFO);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
}
dev_dbg(port->dev,
"%s - total written %d bytes, CTL: %x, RTS: %x, baud: %x\n",
__func__,
port->icount.tx,
ioread8(port->membase + TIMBUART_CTRL),
port->mctrl & TIOCM_RTS,
ioread8(port->membase + TIMBUART_BAUDRATE));
}
static void timbuart_handle_tx_port(struct uart_port *port, u32 isr, u32 *ier)
{
struct timbuart_port *uart =
container_of(port, struct timbuart_port, port);
struct circ_buf *xmit = &port->state->xmit;
if (uart_circ_empty(xmit) || uart_tx_stopped(port))
return;
if (port->x_char)
return;
if (isr & TXFLAGS) {
timbuart_tx_chars(port);
/* clear all TX interrupts */
iowrite32(TXFLAGS, port->membase + TIMBUART_ISR);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
} else
/* Re-enable any tx interrupt */
*ier |= uart->last_ier & TXFLAGS;
/* enable interrupts if there are chars in the transmit buffer,
* Or if we delivered some bytes and want the almost empty interrupt
* we wake up the upper layer later when we got the interrupt
* to give it some time to go out...
*/
if (!uart_circ_empty(xmit))
*ier |= TXBAE;
dev_dbg(port->dev, "%s - leaving\n", __func__);
}
static void timbuart_handle_rx_port(struct uart_port *port, u32 isr, u32 *ier)
{
if (isr & RXFLAGS) {
/* Some RX status is set */
if (isr & RXBF) {
u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
TIMBUART_CTRL_FLSHRX;
iowrite8(ctl, port->membase + TIMBUART_CTRL);
port->icount.overrun++;
} else if (isr & (RXDP))
timbuart_rx_chars(port);
/* ack all RX interrupts */
iowrite32(RXFLAGS, port->membase + TIMBUART_ISR);
}
/* always have the RX interrupts enabled */
*ier |= RXBAF | RXBF | RXTT;
dev_dbg(port->dev, "%s - leaving\n", __func__);
}
static void timbuart_tasklet(unsigned long arg)
{
struct timbuart_port *uart = (struct timbuart_port *)arg;
u32 isr, ier = 0;
spin_lock(&uart->port.lock);
isr = ioread32(uart->port.membase + TIMBUART_ISR);
dev_dbg(uart->port.dev, "%s ISR: %x\n", __func__, isr);
if (!uart->usedma)
timbuart_handle_tx_port(&uart->port, isr, &ier);
timbuart_mctrl_check(&uart->port, isr, &ier);
if (!uart->usedma)
timbuart_handle_rx_port(&uart->port, isr, &ier);
iowrite32(ier, uart->port.membase + TIMBUART_IER);
spin_unlock(&uart->port.lock);
dev_dbg(uart->port.dev, "%s leaving\n", __func__);
}
static unsigned int timbuart_get_mctrl(struct uart_port *port)
{
u8 cts = ioread8(port->membase + TIMBUART_CTRL);
dev_dbg(port->dev, "%s - cts %x\n", __func__, cts);
if (cts & TIMBUART_CTRL_CTS)
return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
else
return TIOCM_DSR | TIOCM_CAR;
}
static void timbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
dev_dbg(port->dev, "%s - %x\n", __func__, mctrl);
if (mctrl & TIOCM_RTS)
iowrite8(TIMBUART_CTRL_RTS, port->membase + TIMBUART_CTRL);
else
iowrite8(0, port->membase + TIMBUART_CTRL);
}
static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier)
{
unsigned int cts;
if (isr & CTS_DELTA) {
/* ack */
iowrite32(CTS_DELTA, port->membase + TIMBUART_ISR);
cts = timbuart_get_mctrl(port);
uart_handle_cts_change(port, cts & TIOCM_CTS);
wake_up_interruptible(&port->state->port.delta_msr_wait);
}
*ier |= CTS_DELTA;
}
static void timbuart_break_ctl(struct uart_port *port, int ctl)
{
/* N/A */
}
static int timbuart_startup(struct uart_port *port)
{
struct timbuart_port *uart =
container_of(port, struct timbuart_port, port);
dev_dbg(port->dev, "%s\n", __func__);
iowrite8(TIMBUART_CTRL_FLSHRX, port->membase + TIMBUART_CTRL);
iowrite32(0x1ff, port->membase + TIMBUART_ISR);
/* Enable all but TX interrupts */
iowrite32(RXBAF | RXBF | RXTT | CTS_DELTA,
port->membase + TIMBUART_IER);
return request_irq(port->irq, timbuart_handleinterrupt, IRQF_SHARED,
"timb-uart", uart);
}
static void timbuart_shutdown(struct uart_port *port)
{
struct timbuart_port *uart =
container_of(port, struct timbuart_port, port);
dev_dbg(port->dev, "%s\n", __func__);
free_irq(port->irq, uart);
iowrite32(0, port->membase + TIMBUART_IER);
timbuart_flush_buffer(port);
}
static int get_bindex(int baud)
{
int i;
for (i = 0; i < ARRAY_SIZE(baudrates); i++)
if (baud <= baudrates[i])
return i;
return -1;
}
static void timbuart_set_termios(struct uart_port *port,
struct ktermios *termios,
struct ktermios *old)
{
unsigned int baud;
short bindex;
unsigned long flags;
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
bindex = get_bindex(baud);
dev_dbg(port->dev, "%s - bindex %d\n", __func__, bindex);
if (bindex < 0)
bindex = 0;
baud = baudrates[bindex];
/* The serial layer calls into this once with old = NULL when setting
up initially */
if (old)
tty_termios_copy_hw(termios, old);
tty_termios_encode_baud_rate(termios, baud, baud);
spin_lock_irqsave(&port->lock, flags);
iowrite8((u8)bindex, port->membase + TIMBUART_BAUDRATE);
uart_update_timeout(port, termios->c_cflag, baud);
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *timbuart_type(struct uart_port *port)
{
return port->type == PORT_UNKNOWN ? "timbuart" : NULL;
}
/* We do not request/release mappings of the registers here,
* currently it's done in the proble function.
*/
static void timbuart_release_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
int size =
resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
if (port->flags & UPF_IOREMAP) {
iounmap(port->membase);
port->membase = NULL;
}
release_mem_region(port->mapbase, size);
}
static int timbuart_request_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
int size =
resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
if (!request_mem_region(port->mapbase, size, "timb-uart"))
return -EBUSY;
if (port->flags & UPF_IOREMAP) {
port->membase = ioremap(port->mapbase, size);
if (port->membase == NULL) {
release_mem_region(port->mapbase, size);
return -ENOMEM;
}
}
return 0;
}
static irqreturn_t timbuart_handleinterrupt(int irq, void *devid)
{
struct timbuart_port *uart = (struct timbuart_port *)devid;
if (ioread8(uart->port.membase + TIMBUART_IPR)) {
uart->last_ier = ioread32(uart->port.membase + TIMBUART_IER);
/* disable interrupts, the tasklet enables them again */
iowrite32(0, uart->port.membase + TIMBUART_IER);
/* fire off bottom half */
tasklet_schedule(&uart->tasklet);
return IRQ_HANDLED;
} else
return IRQ_NONE;
}
/*
* Configure/autoconfigure the port.
*/
static void timbuart_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE) {
port->type = PORT_TIMBUART;
timbuart_request_port(port);
}
}
static int timbuart_verify_port(struct uart_port *port,
struct serial_struct *ser)
{
/* we don't want the core code to modify any port params */
return -EINVAL;
}
static struct uart_ops timbuart_ops = {
.tx_empty = timbuart_tx_empty,
.set_mctrl = timbuart_set_mctrl,
.get_mctrl = timbuart_get_mctrl,
.stop_tx = timbuart_stop_tx,
.start_tx = timbuart_start_tx,
.flush_buffer = timbuart_flush_buffer,
.stop_rx = timbuart_stop_rx,
.break_ctl = timbuart_break_ctl,
.startup = timbuart_startup,
.shutdown = timbuart_shutdown,
.set_termios = timbuart_set_termios,
.type = timbuart_type,
.release_port = timbuart_release_port,
.request_port = timbuart_request_port,
.config_port = timbuart_config_port,
.verify_port = timbuart_verify_port
};
static struct uart_driver timbuart_driver = {
.owner = THIS_MODULE,
.driver_name = "timberdale_uart",
.dev_name = "ttyTU",
.major = TIMBUART_MAJOR,
.minor = TIMBUART_MINOR,
.nr = 1
};
static int timbuart_probe(struct platform_device *dev)
{
int err, irq;
struct timbuart_port *uart;
struct resource *iomem;
dev_dbg(&dev->dev, "%s\n", __func__);
uart = kzalloc(sizeof(*uart), GFP_KERNEL);
if (!uart) {
err = -EINVAL;
goto err_mem;
}
uart->usedma = 0;
uart->port.uartclk = 3250000 * 16;
uart->port.fifosize = TIMBUART_FIFO_SIZE;
uart->port.regshift = 2;
uart->port.iotype = UPIO_MEM;
uart->port.ops = &timbuart_ops;
uart->port.irq = 0;
uart->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
uart->port.line = 0;
uart->port.dev = &dev->dev;
iomem = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (!iomem) {
err = -ENOMEM;
goto err_register;
}
uart->port.mapbase = iomem->start;
uart->port.membase = NULL;
irq = platform_get_irq(dev, 0);
if (irq < 0) {
err = -EINVAL;
goto err_register;
}
uart->port.irq = irq;
tasklet_init(&uart->tasklet, timbuart_tasklet, (unsigned long)uart);
err = uart_register_driver(&timbuart_driver);
if (err)
goto err_register;
err = uart_add_one_port(&timbuart_driver, &uart->port);
if (err)
goto err_add_port;
platform_set_drvdata(dev, uart);
return 0;
err_add_port:
uart_unregister_driver(&timbuart_driver);
err_register:
kfree(uart);
err_mem:
printk(KERN_ERR "timberdale: Failed to register Timberdale UART: %d\n",
err);
return err;
}
static int timbuart_remove(struct platform_device *dev)
{
struct timbuart_port *uart = platform_get_drvdata(dev);
tasklet_kill(&uart->tasklet);
uart_remove_one_port(&timbuart_driver, &uart->port);
uart_unregister_driver(&timbuart_driver);
kfree(uart);
return 0;
}
static struct platform_driver timbuart_platform_driver = {
.driver = {
.name = "timb-uart",
},
.probe = timbuart_probe,
.remove = timbuart_remove,
};
module_platform_driver(timbuart_platform_driver);
MODULE_DESCRIPTION("Timberdale UART driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:timb-uart");