linux/drivers/ipack/devices/ipoctal.c
Samuel Iglesias Gonsalvez 9d01b6f064 ipack/devices/ipoctal: rework disable TX when the TX buffer is empty
Depending of the device, it disables the TX mode in different places when there
is no more data to transmit.

This patch reorder them and disable the TX mode in the same place.

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 18:24:38 -08:00

716 lines
18 KiB
C

/**
* ipoctal.c
*
* driver for the GE IP-OCTAL boards
*
* Copyright (C) 2009-2012 CERN (www.cern.ch)
* Author: Nicolas Serafini, EIC2 SA
* Author: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
*
* 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; version 2 of the License.
*/
#include <linux/device.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/serial.h>
#include <linux/tty_flip.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/ipack.h>
#include "ipoctal.h"
#include "scc2698.h"
#define IP_OCTAL_ID_SPACE_VECTOR 0x41
#define IP_OCTAL_NB_BLOCKS 4
static const struct tty_operations ipoctal_fops;
struct ipoctal_channel {
struct ipoctal_stats stats;
unsigned int nb_bytes;
wait_queue_head_t queue;
spinlock_t lock;
unsigned int pointer_read;
unsigned int pointer_write;
struct tty_port tty_port;
union scc2698_channel __iomem *regs;
union scc2698_block __iomem *block_regs;
unsigned int board_id;
u8 isr_rx_rdy_mask;
u8 isr_tx_rdy_mask;
};
struct ipoctal {
struct ipack_device *dev;
unsigned int board_id;
struct ipoctal_channel channel[NR_CHANNELS];
struct tty_driver *tty_drv;
u8 __iomem *mem8_space;
u8 __iomem *int_space;
};
static int ipoctal_port_activate(struct tty_port *port, struct tty_struct *tty)
{
struct ipoctal_channel *channel;
channel = dev_get_drvdata(tty->dev);
iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
return 0;
}
static int ipoctal_open(struct tty_struct *tty, struct file *file)
{
struct ipoctal_channel *channel;
channel = dev_get_drvdata(tty->dev);
tty->driver_data = channel;
return tty_port_open(&channel->tty_port, tty, file);
}
static void ipoctal_reset_stats(struct ipoctal_stats *stats)
{
stats->tx = 0;
stats->rx = 0;
stats->rcv_break = 0;
stats->framing_err = 0;
stats->overrun_err = 0;
stats->parity_err = 0;
}
static void ipoctal_free_channel(struct ipoctal_channel *channel)
{
ipoctal_reset_stats(&channel->stats);
channel->pointer_read = 0;
channel->pointer_write = 0;
channel->nb_bytes = 0;
}
static void ipoctal_close(struct tty_struct *tty, struct file *filp)
{
struct ipoctal_channel *channel = tty->driver_data;
tty_port_close(&channel->tty_port, tty, filp);
ipoctal_free_channel(channel);
}
static int ipoctal_get_icount(struct tty_struct *tty,
struct serial_icounter_struct *icount)
{
struct ipoctal_channel *channel = tty->driver_data;
icount->cts = 0;
icount->dsr = 0;
icount->rng = 0;
icount->dcd = 0;
icount->rx = channel->stats.rx;
icount->tx = channel->stats.tx;
icount->frame = channel->stats.framing_err;
icount->parity = channel->stats.parity_err;
icount->brk = channel->stats.rcv_break;
return 0;
}
static void ipoctal_irq_rx(struct ipoctal_channel *channel,
struct tty_struct *tty, u8 sr)
{
unsigned char value;
unsigned char flag;
u8 isr;
do {
value = ioread8(&channel->regs->r.rhr);
flag = TTY_NORMAL;
/* Error: count statistics */
if (sr & SR_ERROR) {
iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
if (sr & SR_OVERRUN_ERROR) {
channel->stats.overrun_err++;
/* Overrun doesn't affect the current character*/
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
}
if (sr & SR_PARITY_ERROR) {
channel->stats.parity_err++;
flag = TTY_PARITY;
}
if (sr & SR_FRAMING_ERROR) {
channel->stats.framing_err++;
flag = TTY_FRAME;
}
if (sr & SR_RECEIVED_BREAK) {
iowrite8(CR_CMD_RESET_BREAK_CHANGE, &channel->regs->w.cr);
channel->stats.rcv_break++;
flag = TTY_BREAK;
}
}
tty_insert_flip_char(tty, value, flag);
/* Check if there are more characters in RX FIFO
* If there are more, the isr register for this channel
* has enabled the RxRDY|FFULL bit.
*/
isr = ioread8(&channel->block_regs->r.isr);
sr = ioread8(&channel->regs->r.sr);
} while (isr & channel->isr_rx_rdy_mask);
tty_flip_buffer_push(tty);
}
static void ipoctal_irq_tx(struct ipoctal_channel *channel)
{
unsigned char value;
unsigned int *pointer_write = &channel->pointer_write;
if (channel->nb_bytes == 0)
return;
value = channel->tty_port.xmit_buf[*pointer_write];
iowrite8(value, &channel->regs->w.thr);
channel->stats.tx++;
(*pointer_write)++;
*pointer_write = *pointer_write % PAGE_SIZE;
channel->nb_bytes--;
}
static void ipoctal_irq_channel(struct ipoctal_channel *channel)
{
u8 isr, sr;
struct tty_struct *tty;
tty = tty_port_tty_get(&channel->tty_port);
if (!tty)
return;
/* The HW is organized in pair of channels. See which register we need
* to read from */
isr = ioread8(&channel->block_regs->r.isr);
sr = ioread8(&channel->regs->r.sr);
if ((sr & SR_TX_EMPTY) && (channel->nb_bytes == 0)) {
iowrite8(CR_DISABLE_TX, &channel->regs->w.cr);
/* In case of RS-485, change from TX to RX when finishing TX.
* Half-duplex. */
if (channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) {
iowrite8(CR_CMD_NEGATE_RTSN, &channel->regs->w.cr);
iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
}
}
/* RX data */
if ((isr & channel->isr_rx_rdy_mask) && (sr & SR_RX_READY))
ipoctal_irq_rx(channel, tty, sr);
/* TX of each character */
if ((isr & channel->isr_tx_rdy_mask) && (sr & SR_TX_READY))
ipoctal_irq_tx(channel);
tty_flip_buffer_push(tty);
tty_kref_put(tty);
}
static irqreturn_t ipoctal_irq_handler(void *arg)
{
unsigned int i;
struct ipoctal *ipoctal = (struct ipoctal *) arg;
/* Check all channels */
for (i = 0; i < NR_CHANNELS; i++)
ipoctal_irq_channel(&ipoctal->channel[i]);
/* Clear the IPack device interrupt */
readw(ipoctal->int_space + ACK_INT_REQ0);
readw(ipoctal->int_space + ACK_INT_REQ1);
return IRQ_HANDLED;
}
static const struct tty_port_operations ipoctal_tty_port_ops = {
.dtr_rts = NULL,
.activate = ipoctal_port_activate,
};
static int ipoctal_inst_slot(struct ipoctal *ipoctal, unsigned int bus_nr,
unsigned int slot)
{
int res;
int i;
struct tty_driver *tty;
char name[20];
struct ipoctal_channel *channel;
struct ipack_region *region;
void __iomem *addr;
union scc2698_channel __iomem *chan_regs;
union scc2698_block __iomem *block_regs;
ipoctal->board_id = ipoctal->dev->id_device;
region = &ipoctal->dev->region[IPACK_IO_SPACE];
addr = devm_ioremap_nocache(&ipoctal->dev->dev,
region->start, region->size);
if (!addr) {
dev_err(&ipoctal->dev->dev,
"Unable to map slot [%d:%d] IO space!\n",
bus_nr, slot);
return -EADDRNOTAVAIL;
}
/* Save the virtual address to access the registers easily */
chan_regs =
(union scc2698_channel __iomem *) addr;
block_regs =
(union scc2698_block __iomem *) addr;
region = &ipoctal->dev->region[IPACK_INT_SPACE];
ipoctal->int_space =
devm_ioremap_nocache(&ipoctal->dev->dev,
region->start, region->size);
if (!ipoctal->int_space) {
dev_err(&ipoctal->dev->dev,
"Unable to map slot [%d:%d] INT space!\n",
bus_nr, slot);
return -EADDRNOTAVAIL;
}
region = &ipoctal->dev->region[IPACK_MEM8_SPACE];
ipoctal->mem8_space =
devm_ioremap_nocache(&ipoctal->dev->dev,
region->start, 0x8000);
if (!addr) {
dev_err(&ipoctal->dev->dev,
"Unable to map slot [%d:%d] MEM8 space!\n",
bus_nr, slot);
return -EADDRNOTAVAIL;
}
/* Disable RX and TX before touching anything */
for (i = 0; i < NR_CHANNELS ; i++) {
struct ipoctal_channel *channel = &ipoctal->channel[i];
channel->regs = chan_regs + i;
channel->block_regs = block_regs + (i >> 1);
channel->board_id = ipoctal->board_id;
if (i & 1) {
channel->isr_tx_rdy_mask = ISR_TxRDY_B;
channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_B;
} else {
channel->isr_tx_rdy_mask = ISR_TxRDY_A;
channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_A;
}
iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
iowrite8(MR1_CHRL_8_BITS | MR1_ERROR_CHAR | MR1_RxINT_RxRDY,
&channel->regs->w.mr); /* mr1 */
iowrite8(0, &channel->regs->w.mr); /* mr2 */
iowrite8(TX_CLK_9600 | RX_CLK_9600, &channel->regs->w.csr);
}
for (i = 0; i < IP_OCTAL_NB_BLOCKS; i++) {
iowrite8(ACR_BRG_SET2, &block_regs[i].w.acr);
iowrite8(OPCR_MPP_OUTPUT | OPCR_MPOa_RTSN | OPCR_MPOb_RTSN,
&block_regs[i].w.opcr);
iowrite8(IMR_TxRDY_A | IMR_RxRDY_FFULL_A | IMR_DELTA_BREAK_A |
IMR_TxRDY_B | IMR_RxRDY_FFULL_B | IMR_DELTA_BREAK_B,
&block_regs[i].w.imr);
}
/*
* IP-OCTAL has different addresses to copy its IRQ vector.
* Depending of the carrier these addresses are accesible or not.
* More info in the datasheet.
*/
ipoctal->dev->bus->ops->request_irq(ipoctal->dev,
ipoctal_irq_handler, ipoctal);
/* Dummy write */
iowrite8(1, ipoctal->mem8_space + 1);
/* Register the TTY device */
/* Each IP-OCTAL channel is a TTY port */
tty = alloc_tty_driver(NR_CHANNELS);
if (!tty)
return -ENOMEM;
/* Fill struct tty_driver with ipoctal data */
tty->owner = THIS_MODULE;
tty->driver_name = KBUILD_MODNAME;
sprintf(name, KBUILD_MODNAME ".%d.%d.", bus_nr, slot);
tty->name = name;
tty->major = 0;
tty->minor_start = 0;
tty->type = TTY_DRIVER_TYPE_SERIAL;
tty->subtype = SERIAL_TYPE_NORMAL;
tty->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
tty->init_termios = tty_std_termios;
tty->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
tty->init_termios.c_ispeed = 9600;
tty->init_termios.c_ospeed = 9600;
tty_set_operations(tty, &ipoctal_fops);
res = tty_register_driver(tty);
if (res) {
dev_err(&ipoctal->dev->dev, "Can't register tty driver.\n");
put_tty_driver(tty);
return res;
}
/* Save struct tty_driver for use it when uninstalling the device */
ipoctal->tty_drv = tty;
for (i = 0; i < NR_CHANNELS; i++) {
struct device *tty_dev;
channel = &ipoctal->channel[i];
tty_port_init(&channel->tty_port);
tty_port_alloc_xmit_buf(&channel->tty_port);
channel->tty_port.ops = &ipoctal_tty_port_ops;
ipoctal_reset_stats(&channel->stats);
channel->nb_bytes = 0;
spin_lock_init(&channel->lock);
channel->pointer_read = 0;
channel->pointer_write = 0;
tty_dev = tty_port_register_device(&channel->tty_port, tty, i, NULL);
if (IS_ERR(tty_dev)) {
dev_err(&ipoctal->dev->dev, "Failed to register tty device.\n");
tty_port_destroy(&channel->tty_port);
continue;
}
dev_set_drvdata(tty_dev, channel);
/*
* Enable again the RX. TX will be enabled when
* there is something to send
*/
iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
}
return 0;
}
static inline int ipoctal_copy_write_buffer(struct ipoctal_channel *channel,
const unsigned char *buf,
int count)
{
unsigned long flags;
int i;
unsigned int *pointer_read = &channel->pointer_read;
/* Copy the bytes from the user buffer to the internal one */
for (i = 0; i < count; i++) {
if (i <= (PAGE_SIZE - channel->nb_bytes)) {
spin_lock_irqsave(&channel->lock, flags);
channel->tty_port.xmit_buf[*pointer_read] = buf[i];
*pointer_read = (*pointer_read + 1) % PAGE_SIZE;
channel->nb_bytes++;
spin_unlock_irqrestore(&channel->lock, flags);
} else {
break;
}
}
return i;
}
static int ipoctal_write_tty(struct tty_struct *tty,
const unsigned char *buf, int count)
{
struct ipoctal_channel *channel = tty->driver_data;
unsigned int char_copied;
char_copied = ipoctal_copy_write_buffer(channel, buf, count);
/* As the IP-OCTAL 485 only supports half duplex, do it manually */
if (channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) {
iowrite8(CR_DISABLE_RX, &channel->regs->w.cr);
iowrite8(CR_CMD_ASSERT_RTSN, &channel->regs->w.cr);
}
/*
* Send a packet and then disable TX to avoid failure after several send
* operations
*/
iowrite8(CR_ENABLE_TX, &channel->regs->w.cr);
return char_copied;
}
static int ipoctal_write_room(struct tty_struct *tty)
{
struct ipoctal_channel *channel = tty->driver_data;
return PAGE_SIZE - channel->nb_bytes;
}
static int ipoctal_chars_in_buffer(struct tty_struct *tty)
{
struct ipoctal_channel *channel = tty->driver_data;
return channel->nb_bytes;
}
static void ipoctal_set_termios(struct tty_struct *tty,
struct ktermios *old_termios)
{
unsigned int cflag;
unsigned char mr1 = 0;
unsigned char mr2 = 0;
unsigned char csr = 0;
struct ipoctal_channel *channel = tty->driver_data;
speed_t baud;
cflag = tty->termios.c_cflag;
/* Disable and reset everything before change the setup */
iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
/* Set Bits per chars */
switch (cflag & CSIZE) {
case CS6:
mr1 |= MR1_CHRL_6_BITS;
break;
case CS7:
mr1 |= MR1_CHRL_7_BITS;
break;
case CS8:
default:
mr1 |= MR1_CHRL_8_BITS;
/* By default, select CS8 */
tty->termios.c_cflag = (cflag & ~CSIZE) | CS8;
break;
}
/* Set Parity */
if (cflag & PARENB)
if (cflag & PARODD)
mr1 |= MR1_PARITY_ON | MR1_PARITY_ODD;
else
mr1 |= MR1_PARITY_ON | MR1_PARITY_EVEN;
else
mr1 |= MR1_PARITY_OFF;
/* Mark or space parity is not supported */
tty->termios.c_cflag &= ~CMSPAR;
/* Set stop bits */
if (cflag & CSTOPB)
mr2 |= MR2_STOP_BITS_LENGTH_2;
else
mr2 |= MR2_STOP_BITS_LENGTH_1;
/* Set the flow control */
switch (channel->board_id) {
case IPACK1_DEVICE_ID_SBS_OCTAL_232:
if (cflag & CRTSCTS) {
mr1 |= MR1_RxRTS_CONTROL_ON;
mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_ON;
} else {
mr1 |= MR1_RxRTS_CONTROL_OFF;
mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_OFF;
}
break;
case IPACK1_DEVICE_ID_SBS_OCTAL_422:
mr1 |= MR1_RxRTS_CONTROL_OFF;
mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_OFF;
break;
case IPACK1_DEVICE_ID_SBS_OCTAL_485:
mr1 |= MR1_RxRTS_CONTROL_OFF;
mr2 |= MR2_TxRTS_CONTROL_ON | MR2_CTS_ENABLE_TX_OFF;
break;
default:
return;
break;
}
baud = tty_get_baud_rate(tty);
tty_termios_encode_baud_rate(&tty->termios, baud, baud);
/* Set baud rate */
switch (baud) {
case 75:
csr |= TX_CLK_75 | RX_CLK_75;
break;
case 110:
csr |= TX_CLK_110 | RX_CLK_110;
break;
case 150:
csr |= TX_CLK_150 | RX_CLK_150;
break;
case 300:
csr |= TX_CLK_300 | RX_CLK_300;
break;
case 600:
csr |= TX_CLK_600 | RX_CLK_600;
break;
case 1200:
csr |= TX_CLK_1200 | RX_CLK_1200;
break;
case 1800:
csr |= TX_CLK_1800 | RX_CLK_1800;
break;
case 2000:
csr |= TX_CLK_2000 | RX_CLK_2000;
break;
case 2400:
csr |= TX_CLK_2400 | RX_CLK_2400;
break;
case 4800:
csr |= TX_CLK_4800 | RX_CLK_4800;
break;
case 9600:
csr |= TX_CLK_9600 | RX_CLK_9600;
break;
case 19200:
csr |= TX_CLK_19200 | RX_CLK_19200;
break;
case 38400:
default:
csr |= TX_CLK_38400 | RX_CLK_38400;
/* In case of default, we establish 38400 bps */
tty_termios_encode_baud_rate(&tty->termios, 38400, 38400);
break;
}
mr1 |= MR1_ERROR_CHAR;
mr1 |= MR1_RxINT_RxRDY;
/* Write the control registers */
iowrite8(mr1, &channel->regs->w.mr);
iowrite8(mr2, &channel->regs->w.mr);
iowrite8(csr, &channel->regs->w.csr);
/* Enable again the RX */
iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
}
static void ipoctal_hangup(struct tty_struct *tty)
{
unsigned long flags;
struct ipoctal_channel *channel = tty->driver_data;
if (channel == NULL)
return;
spin_lock_irqsave(&channel->lock, flags);
channel->nb_bytes = 0;
channel->pointer_read = 0;
channel->pointer_write = 0;
spin_unlock_irqrestore(&channel->lock, flags);
tty_port_hangup(&channel->tty_port);
iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
clear_bit(ASYNCB_INITIALIZED, &channel->tty_port.flags);
wake_up_interruptible(&channel->tty_port.open_wait);
}
static const struct tty_operations ipoctal_fops = {
.ioctl = NULL,
.open = ipoctal_open,
.close = ipoctal_close,
.write = ipoctal_write_tty,
.set_termios = ipoctal_set_termios,
.write_room = ipoctal_write_room,
.chars_in_buffer = ipoctal_chars_in_buffer,
.get_icount = ipoctal_get_icount,
.hangup = ipoctal_hangup,
};
static int ipoctal_probe(struct ipack_device *dev)
{
int res;
struct ipoctal *ipoctal;
ipoctal = kzalloc(sizeof(struct ipoctal), GFP_KERNEL);
if (ipoctal == NULL)
return -ENOMEM;
ipoctal->dev = dev;
res = ipoctal_inst_slot(ipoctal, dev->bus->bus_nr, dev->slot);
if (res)
goto out_uninst;
dev_set_drvdata(&dev->dev, ipoctal);
return 0;
out_uninst:
kfree(ipoctal);
return res;
}
static void __ipoctal_remove(struct ipoctal *ipoctal)
{
int i;
ipoctal->dev->bus->ops->free_irq(ipoctal->dev);
for (i = 0; i < NR_CHANNELS; i++) {
struct ipoctal_channel *channel = &ipoctal->channel[i];
tty_unregister_device(ipoctal->tty_drv, i);
tty_port_free_xmit_buf(&channel->tty_port);
tty_port_destroy(&channel->tty_port);
}
tty_unregister_driver(ipoctal->tty_drv);
put_tty_driver(ipoctal->tty_drv);
kfree(ipoctal);
}
static void ipoctal_remove(struct ipack_device *idev)
{
__ipoctal_remove(dev_get_drvdata(&idev->dev));
}
static DEFINE_IPACK_DEVICE_TABLE(ipoctal_ids) = {
{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
IPACK1_DEVICE_ID_SBS_OCTAL_232) },
{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
IPACK1_DEVICE_ID_SBS_OCTAL_422) },
{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
IPACK1_DEVICE_ID_SBS_OCTAL_485) },
{ 0, },
};
MODULE_DEVICE_TABLE(ipack, ipoctal_ids);
static const struct ipack_driver_ops ipoctal_drv_ops = {
.probe = ipoctal_probe,
.remove = ipoctal_remove,
};
static struct ipack_driver driver = {
.ops = &ipoctal_drv_ops,
.id_table = ipoctal_ids,
};
static int __init ipoctal_init(void)
{
return ipack_driver_register(&driver, THIS_MODULE, KBUILD_MODNAME);
}
static void __exit ipoctal_exit(void)
{
ipack_driver_unregister(&driver);
}
MODULE_DESCRIPTION("IP-Octal 232, 422 and 485 device driver");
MODULE_LICENSE("GPL");
module_init(ipoctal_init);
module_exit(ipoctal_exit);