q3k/linux
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
linux/drivers/tty/serial/mfd.c
Feng Tang a5f4dbf0ae serial: mfd: remove the timeout workaround for A0 
This is kind of a revert for commit 669b7a0938 "hsu: add a periodic
timer to check dma rx channel", which is a workaround for a bug in A0
stepping silicon, where a dma rx data timeout is missing for some case.
Since new silicon has fixed it and the old version is phasing out, no
need to carry on it any more.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 11:40:46 -08:00

1475 lines
36 KiB
C
Raw Blame History

/*
* mfd.c: driver for High Speed UART device of Intel Medfield platform
*
* Refer pxa.c, 8250.c and some other drivers in drivers/serial/
*
* (C) Copyright 2010 Intel Corporation
*
* 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.
*/
/* Notes:
* 1. DMA channel allocation: 0/1 channel are assigned to port 0,
* 2/3 chan to port 1, 4/5 chan to port 3. Even number chans
* are used for RX, odd chans for TX
*
* 2. In A0 stepping, UART will not support TX half empty flag
*
* 3. The RI/DSR/DCD/DTR are not pinned out, DCD & DSR are always
* asserted, only when the HW is reset the DDCD and DDSR will
* be triggered
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/slab.h>
#include <linux/serial_reg.h>
#include <linux/circ_buf.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial_mfd.h>
#include <linux/dma-mapping.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/debugfs.h>
#define MFD_HSU_A0_STEPPING 1
#define HSU_DMA_BUF_SIZE 2048
#define chan_readl(chan, offset) readl(chan->reg + offset)
#define chan_writel(chan, offset, val) writel(val, chan->reg + offset)
#define mfd_readl(obj, offset) readl(obj->reg + offset)
#define mfd_writel(obj, offset, val) writel(val, obj->reg + offset)
struct hsu_dma_buffer {
u8 *buf;
dma_addr_t dma_addr;
u32 dma_size;
u32 ofs;
};
struct hsu_dma_chan {
u32 id;
enum dma_data_direction dirt;
struct uart_hsu_port *uport;
void __iomem *reg;
};
struct uart_hsu_port {
struct uart_port port;
unsigned char ier;
unsigned char lcr;
unsigned char mcr;
unsigned int lsr_break_flag;
char name[12];
int index;
struct device *dev;
struct hsu_dma_chan *txc;
struct hsu_dma_chan *rxc;
struct hsu_dma_buffer txbuf;
struct hsu_dma_buffer rxbuf;
int use_dma; /* flag for DMA/PIO */
int running;
int dma_tx_on;
};
/* Top level data structure of HSU */
struct hsu_port {
void __iomem *reg;
unsigned long paddr;
unsigned long iolen;
u32 irq;
struct uart_hsu_port port[3];
struct hsu_dma_chan chans[10];
struct dentry *debugfs;
};
static inline unsigned int serial_in(struct uart_hsu_port *up, int offset)
{
unsigned int val;
if (offset > UART_MSR) {
offset <<= 2;
val = readl(up->port.membase + offset);
} else
val = (unsigned int)readb(up->port.membase + offset);
return val;
}
static inline void serial_out(struct uart_hsu_port *up, int offset, int value)
{
if (offset > UART_MSR) {
offset <<= 2;
writel(value, up->port.membase + offset);
} else {
unsigned char val = value & 0xff;
writeb(val, up->port.membase + offset);
}
}
#ifdef CONFIG_DEBUG_FS
#define HSU_REGS_BUFSIZE 1024
static int hsu_show_regs_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static ssize_t port_show_regs(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
struct uart_hsu_port *up = file->private_data;
char *buf;
u32 len = 0;
ssize_t ret;
buf = kzalloc(HSU_REGS_BUFSIZE, GFP_KERNEL);
if (!buf)
return 0;
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"MFD HSU port[%d] regs:\n", up->index);
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"=================================\n");
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"IER: \t\t0x%08x\n", serial_in(up, UART_IER));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"IIR: \t\t0x%08x\n", serial_in(up, UART_IIR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"LCR: \t\t0x%08x\n", serial_in(up, UART_LCR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"MCR: \t\t0x%08x\n", serial_in(up, UART_MCR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"LSR: \t\t0x%08x\n", serial_in(up, UART_LSR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"MSR: \t\t0x%08x\n", serial_in(up, UART_MSR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"FOR: \t\t0x%08x\n", serial_in(up, UART_FOR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"PS: \t\t0x%08x\n", serial_in(up, UART_PS));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"MUL: \t\t0x%08x\n", serial_in(up, UART_MUL));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"DIV: \t\t0x%08x\n", serial_in(up, UART_DIV));
if (len > HSU_REGS_BUFSIZE)
len = HSU_REGS_BUFSIZE;
ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
kfree(buf);
return ret;
}
static ssize_t dma_show_regs(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
struct hsu_dma_chan *chan = file->private_data;
char *buf;
u32 len = 0;
ssize_t ret;
buf = kzalloc(HSU_REGS_BUFSIZE, GFP_KERNEL);
if (!buf)
return 0;
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"MFD HSU DMA channel [%d] regs:\n", chan->id);
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"=================================\n");
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"CR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_CR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"DCR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_DCR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"BSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_BSR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"MOTSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_MOTSR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D0SAR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D0TSR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D1SAR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D1TSR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D2SAR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D2TSR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D3SAR));
len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
"D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D3TSR));
if (len > HSU_REGS_BUFSIZE)
len = HSU_REGS_BUFSIZE;
ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
kfree(buf);
return ret;
}
static const struct file_operations port_regs_ops = {
.owner = THIS_MODULE,
.open = hsu_show_regs_open,
.read = port_show_regs,
.llseek = default_llseek,
};
static const struct file_operations dma_regs_ops = {
.owner = THIS_MODULE,
.open = hsu_show_regs_open,
.read = dma_show_regs,
.llseek = default_llseek,
};
static int hsu_debugfs_init(struct hsu_port *hsu)
{
int i;
char name[32];
hsu->debugfs = debugfs_create_dir("hsu", NULL);
if (!hsu->debugfs)
return -ENOMEM;
for (i = 0; i < 3; i++) {
snprintf(name, sizeof(name), "port_%d_regs", i);
debugfs_create_file(name, S_IFREG | S_IRUGO,
hsu->debugfs, (void *)(&hsu->port[i]), &port_regs_ops);
}
for (i = 0; i < 6; i++) {
snprintf(name, sizeof(name), "dma_chan_%d_regs", i);
debugfs_create_file(name, S_IFREG | S_IRUGO,
hsu->debugfs, (void *)&hsu->chans[i], &dma_regs_ops);
}
return 0;
}
static void hsu_debugfs_remove(struct hsu_port *hsu)
{
if (hsu->debugfs)
debugfs_remove_recursive(hsu->debugfs);
}
#else
static inline int hsu_debugfs_init(struct hsu_port *hsu)
{
return 0;
}
static inline void hsu_debugfs_remove(struct hsu_port *hsu)
{
}
#endif /* CONFIG_DEBUG_FS */
static void serial_hsu_enable_ms(struct uart_port *port)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
up->ier |= UART_IER_MSI;
serial_out(up, UART_IER, up->ier);
}
void hsu_dma_tx(struct uart_hsu_port *up)
{
struct circ_buf *xmit = &up->port.state->xmit;
struct hsu_dma_buffer *dbuf = &up->txbuf;
int count;
/* test_and_set_bit may be better, but anyway it's in lock protected mode */
if (up->dma_tx_on)
return;
/* Update the circ buf info */
xmit->tail += dbuf->ofs;
xmit->tail &= UART_XMIT_SIZE - 1;
up->port.icount.tx += dbuf->ofs;
dbuf->ofs = 0;
/* Disable the channel */
chan_writel(up->txc, HSU_CH_CR, 0x0);
if (!uart_circ_empty(xmit) && !uart_tx_stopped(&up->port)) {
dma_sync_single_for_device(up->port.dev,
dbuf->dma_addr,
dbuf->dma_size,
DMA_TO_DEVICE);
count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
dbuf->ofs = count;
/* Reprogram the channel */
chan_writel(up->txc, HSU_CH_D0SAR, dbuf->dma_addr + xmit->tail);
chan_writel(up->txc, HSU_CH_D0TSR, count);
/* Reenable the channel */
chan_writel(up->txc, HSU_CH_DCR, 0x1
| (0x1 << 8)
| (0x1 << 16)
| (0x1 << 24));
up->dma_tx_on = 1;
chan_writel(up->txc, HSU_CH_CR, 0x1);
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
}
/* The buffer is already cache coherent */
void hsu_dma_start_rx_chan(struct hsu_dma_chan *rxc, struct hsu_dma_buffer *dbuf)
{
dbuf->ofs = 0;
chan_writel(rxc, HSU_CH_BSR, 32);
chan_writel(rxc, HSU_CH_MOTSR, 4);
chan_writel(rxc, HSU_CH_D0SAR, dbuf->dma_addr);
chan_writel(rxc, HSU_CH_D0TSR, dbuf->dma_size);
chan_writel(rxc, HSU_CH_DCR, 0x1 | (0x1 << 8)
| (0x1 << 16)
| (0x1 << 24) /* timeout bit, see HSU Errata 1 */
);
chan_writel(rxc, HSU_CH_CR, 0x3);
}
/* Protected by spin_lock_irqsave(port->lock) */
static void serial_hsu_start_tx(struct uart_port *port)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
if (up->use_dma) {
hsu_dma_tx(up);
} else if (!(up->ier & UART_IER_THRI)) {
up->ier |= UART_IER_THRI;
serial_out(up, UART_IER, up->ier);
}
}
static void serial_hsu_stop_tx(struct uart_port *port)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
struct hsu_dma_chan *txc = up->txc;
if (up->use_dma)
chan_writel(txc, HSU_CH_CR, 0x0);
else if (up->ier & UART_IER_THRI) {
up->ier &= ~UART_IER_THRI;
serial_out(up, UART_IER, up->ier);
}
}
/* This is always called in spinlock protected mode, so
* modify timeout timer is safe here */
void hsu_dma_rx(struct uart_hsu_port *up, u32 int_sts)
{
struct hsu_dma_buffer *dbuf = &up->rxbuf;
struct hsu_dma_chan *chan = up->rxc;
struct uart_port *port = &up->port;
struct tty_struct *tty = port->state->port.tty;
int count;
if (!tty)
return;
/*
* First need to know how many is already transferred,
* then check if its a timeout DMA irq, and return
* the trail bytes out, push them up and reenable the
* channel
*/
/* Timeout IRQ, need wait some time, see Errata 2 */
if (int_sts & 0xf00)
udelay(2);
/* Stop the channel */
chan_writel(chan, HSU_CH_CR, 0x0);
count = chan_readl(chan, HSU_CH_D0SAR) - dbuf->dma_addr;
if (!count) {
/* Restart the channel before we leave */
chan_writel(chan, HSU_CH_CR, 0x3);
return;
}
dma_sync_single_for_cpu(port->dev, dbuf->dma_addr,
dbuf->dma_size, DMA_FROM_DEVICE);
/*
* Head will only wrap around when we recycle
* the DMA buffer, and when that happens, we
* explicitly set tail to 0. So head will
* always be greater than tail.
*/
tty_insert_flip_string(tty, dbuf->buf, count);
port->icount.rx += count;
dma_sync_single_for_device(up->port.dev, dbuf->dma_addr,
dbuf->dma_size, DMA_FROM_DEVICE);
/* Reprogram the channel */
chan_writel(chan, HSU_CH_D0SAR, dbuf->dma_addr);
chan_writel(chan, HSU_CH_D0TSR, dbuf->dma_size);
chan_writel(chan, HSU_CH_DCR, 0x1
| (0x1 << 8)
| (0x1 << 16)
| (0x1 << 24) /* timeout bit, see HSU Errata 1 */
);
tty_flip_buffer_push(tty);
chan_writel(chan, HSU_CH_CR, 0x3);
}
static void serial_hsu_stop_rx(struct uart_port *port)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
struct hsu_dma_chan *chan = up->rxc;
if (up->use_dma)
chan_writel(chan, HSU_CH_CR, 0x2);
else {
up->ier &= ~UART_IER_RLSI;
up->port.read_status_mask &= ~UART_LSR_DR;
serial_out(up, UART_IER, up->ier);
}
}
static inline void receive_chars(struct uart_hsu_port *up, int *status)
{
struct tty_struct *tty = up->port.state->port.tty;
unsigned int ch, flag;
unsigned int max_count = 256;
if (!tty)
return;
do {
ch = serial_in(up, UART_RX);
flag = TTY_NORMAL;
up->port.icount.rx++;
if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
UART_LSR_FE | UART_LSR_OE))) {
dev_warn(up->dev, "We really rush into ERR/BI case"
"status = 0x%02x", *status);
/* For statistics only */
if (*status & UART_LSR_BI) {
*status &= ~(UART_LSR_FE | UART_LSR_PE);
up->port.icount.brk++;
/*
* We do the SysRQ and SAK checking
* here because otherwise the break
* may get masked by ignore_status_mask
* or read_status_mask.
*/
if (uart_handle_break(&up->port))
goto ignore_char;
} else if (*status & UART_LSR_PE)
up->port.icount.parity++;
else if (*status & UART_LSR_FE)
up->port.icount.frame++;
if (*status & UART_LSR_OE)
up->port.icount.overrun++;
/* Mask off conditions which should be ignored. */
*status &= up->port.read_status_mask;
#ifdef CONFIG_SERIAL_MFD_HSU_CONSOLE
if (up->port.cons &&
up->port.cons->index == up->port.line) {
/* Recover the break flag from console xmit */
*status |= up->lsr_break_flag;
up->lsr_break_flag = 0;
}
#endif
if (*status & UART_LSR_BI) {
flag = TTY_BREAK;
} else if (*status & UART_LSR_PE)
flag = TTY_PARITY;
else if (*status & UART_LSR_FE)
flag = TTY_FRAME;
}
if (uart_handle_sysrq_char(&up->port, ch))
goto ignore_char;
uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
ignore_char:
*status = serial_in(up, UART_LSR);
} while ((*status & UART_LSR_DR) && max_count--);
tty_flip_buffer_push(tty);
}
static void transmit_chars(struct uart_hsu_port *up)
{
struct circ_buf *xmit = &up->port.state->xmit;
int count;
if (up->port.x_char) {
serial_out(up, UART_TX, up->port.x_char);
up->port.icount.tx++;
up->port.x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
serial_hsu_stop_tx(&up->port);
return;
}
#ifndef MFD_HSU_A0_STEPPING
count = up->port.fifosize / 2;
#else
/*
* A0 only supports fully empty IRQ, and the first char written
* into it won't clear the EMPT bit, so we may need be cautious
* by useing a shorter buffer
*/
count = up->port.fifosize - 4;
#endif
do {
serial_out(up, UART_TX, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
up->port.icount.tx++;
if (uart_circ_empty(xmit))
break;
} while (--count > 0);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
if (uart_circ_empty(xmit))
serial_hsu_stop_tx(&up->port);
}
static inline void check_modem_status(struct uart_hsu_port *up)
{
int status;
status = serial_in(up, UART_MSR);
if ((status & UART_MSR_ANY_DELTA) == 0)
return;
if (status & UART_MSR_TERI)
up->port.icount.rng++;
if (status & UART_MSR_DDSR)
up->port.icount.dsr++;
/* We may only get DDCD when HW init and reset */
if (status & UART_MSR_DDCD)
uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
/* Will start/stop_tx accordingly */
if (status & UART_MSR_DCTS)
uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
wake_up_interruptible(&up->port.state->port.delta_msr_wait);
}
/*
* This handles the interrupt from one port.
*/
static irqreturn_t port_irq(int irq, void *dev_id)
{
struct uart_hsu_port *up = dev_id;
unsigned int iir, lsr;
unsigned long flags;
if (unlikely(!up->running))
return IRQ_NONE;
spin_lock_irqsave(&up->port.lock, flags);
if (up->use_dma) {
lsr = serial_in(up, UART_LSR);
if (unlikely(lsr & (UART_LSR_BI | UART_LSR_PE |
UART_LSR_FE | UART_LSR_OE)))
dev_warn(up->dev,
"Got lsr irq while using DMA, lsr = 0x%2x\n",
lsr);
check_modem_status(up);
spin_unlock_irqrestore(&up->port.lock, flags);
return IRQ_HANDLED;
}
iir = serial_in(up, UART_IIR);
if (iir & UART_IIR_NO_INT) {
spin_unlock_irqrestore(&up->port.lock, flags);
return IRQ_NONE;
}
lsr = serial_in(up, UART_LSR);
if (lsr & UART_LSR_DR)
receive_chars(up, &lsr);
check_modem_status(up);
/* lsr will be renewed during the receive_chars */
if (lsr & UART_LSR_THRE)
transmit_chars(up);
spin_unlock_irqrestore(&up->port.lock, flags);
return IRQ_HANDLED;
}
static inline void dma_chan_irq(struct hsu_dma_chan *chan)
{
struct uart_hsu_port *up = chan->uport;
unsigned long flags;
u32 int_sts;
spin_lock_irqsave(&up->port.lock, flags);
if (!up->use_dma || !up->running)
goto exit;
/*
* No matter what situation, need read clear the IRQ status
* There is a bug, see Errata 5, HSD 2900918
*/
int_sts = chan_readl(chan, HSU_CH_SR);
/* Rx channel */
if (chan->dirt == DMA_FROM_DEVICE)
hsu_dma_rx(up, int_sts);
/* Tx channel */
if (chan->dirt == DMA_TO_DEVICE) {
chan_writel(chan, HSU_CH_CR, 0x0);
up->dma_tx_on = 0;
hsu_dma_tx(up);
}
exit:
spin_unlock_irqrestore(&up->port.lock, flags);
return;
}
static irqreturn_t dma_irq(int irq, void *dev_id)
{
struct hsu_port *hsu = dev_id;
u32 int_sts, i;
int_sts = mfd_readl(hsu, HSU_GBL_DMAISR);
/* Currently we only have 6 channels may be used */
for (i = 0; i < 6; i++) {
if (int_sts & 0x1)
dma_chan_irq(&hsu->chans[i]);
int_sts >>= 1;
}
return IRQ_HANDLED;
}
static unsigned int serial_hsu_tx_empty(struct uart_port *port)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
unsigned long flags;
unsigned int ret;
spin_lock_irqsave(&up->port.lock, flags);
ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
spin_unlock_irqrestore(&up->port.lock, flags);
return ret;
}
static unsigned int serial_hsu_get_mctrl(struct uart_port *port)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
unsigned char status;
unsigned int ret;
status = serial_in(up, UART_MSR);
ret = 0;
if (status & UART_MSR_DCD)
ret |= TIOCM_CAR;
if (status & UART_MSR_RI)
ret |= TIOCM_RNG;
if (status & UART_MSR_DSR)
ret |= TIOCM_DSR;
if (status & UART_MSR_CTS)
ret |= TIOCM_CTS;
return ret;
}
static void serial_hsu_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
unsigned char mcr = 0;
if (mctrl & TIOCM_RTS)
mcr |= UART_MCR_RTS;
if (mctrl & TIOCM_DTR)
mcr |= UART_MCR_DTR;
if (mctrl & TIOCM_OUT1)
mcr |= UART_MCR_OUT1;
if (mctrl & TIOCM_OUT2)
mcr |= UART_MCR_OUT2;
if (mctrl & TIOCM_LOOP)
mcr |= UART_MCR_LOOP;
mcr |= up->mcr;
serial_out(up, UART_MCR, mcr);
}
static void serial_hsu_break_ctl(struct uart_port *port, int break_state)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
unsigned long flags;
spin_lock_irqsave(&up->port.lock, flags);
if (break_state == -1)
up->lcr |= UART_LCR_SBC;
else
up->lcr &= ~UART_LCR_SBC;
serial_out(up, UART_LCR, up->lcr);
spin_unlock_irqrestore(&up->port.lock, flags);
}
/*
* What special to do:
* 1. chose the 64B fifo mode
* 2. make sure not to select half empty mode for A0 stepping
* 3. start dma or pio depends on configuration
* 4. we only allocate dma memory when needed
*/
static int serial_hsu_startup(struct uart_port *port)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
unsigned long flags;
/*
* Clear the FIFO buffers and disable them.
* (they will be reenabled in set_termios())
*/
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
serial_out(up, UART_FCR, 0);
/* Clear the interrupt registers. */
(void) serial_in(up, UART_LSR);
(void) serial_in(up, UART_RX);
(void) serial_in(up, UART_IIR);
(void) serial_in(up, UART_MSR);
/* Now, initialize the UART, default is 8n1 */
serial_out(up, UART_LCR, UART_LCR_WLEN8);
spin_lock_irqsave(&up->port.lock, flags);
up->port.mctrl |= TIOCM_OUT2;
serial_hsu_set_mctrl(&up->port, up->port.mctrl);
/*
* Finally, enable interrupts. Note: Modem status interrupts
* are set via set_termios(), which will be occurring imminently
* anyway, so we don't enable them here.
*/
if (!up->use_dma)
up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE;
else
up->ier = 0;
serial_out(up, UART_IER, up->ier);
spin_unlock_irqrestore(&up->port.lock, flags);
/* DMA init */
if (up->use_dma) {
struct hsu_dma_buffer *dbuf;
struct circ_buf *xmit = &port->state->xmit;
up->dma_tx_on = 0;
/* First allocate the RX buffer */
dbuf = &up->rxbuf;
dbuf->buf = kzalloc(HSU_DMA_BUF_SIZE, GFP_KERNEL);
if (!dbuf->buf) {
up->use_dma = 0;
goto exit;
}
dbuf->dma_addr = dma_map_single(port->dev,
dbuf->buf,
HSU_DMA_BUF_SIZE,
DMA_FROM_DEVICE);
dbuf->dma_size = HSU_DMA_BUF_SIZE;
/* Start the RX channel right now */
hsu_dma_start_rx_chan(up->rxc, dbuf);
/* Next init the TX DMA */
dbuf = &up->txbuf;
dbuf->buf = xmit->buf;
dbuf->dma_addr = dma_map_single(port->dev,
dbuf->buf,
UART_XMIT_SIZE,
DMA_TO_DEVICE);
dbuf->dma_size = UART_XMIT_SIZE;
/* This should not be changed all around */
chan_writel(up->txc, HSU_CH_BSR, 32);
chan_writel(up->txc, HSU_CH_MOTSR, 4);
dbuf->ofs = 0;
}
exit:
/* And clear the interrupt registers again for luck. */
(void) serial_in(up, UART_LSR);
(void) serial_in(up, UART_RX);
(void) serial_in(up, UART_IIR);
(void) serial_in(up, UART_MSR);
up->running = 1;
return 0;
}
static void serial_hsu_shutdown(struct uart_port *port)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
unsigned long flags;
/* Disable interrupts from this port */
up->ier = 0;
serial_out(up, UART_IER, 0);
up->running = 0;
spin_lock_irqsave(&up->port.lock, flags);
up->port.mctrl &= ~TIOCM_OUT2;
serial_hsu_set_mctrl(&up->port, up->port.mctrl);
spin_unlock_irqrestore(&up->port.lock, flags);
/* Disable break condition and FIFOs */
serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
UART_FCR_CLEAR_RCVR |
UART_FCR_CLEAR_XMIT);
serial_out(up, UART_FCR, 0);
}
static void
serial_hsu_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
struct tty_struct *tty = port->state->port.tty;
unsigned char cval, fcr = 0;
unsigned long flags;
unsigned int baud, quot;
u32 ps, mul;
switch (termios->c_cflag & CSIZE) {
case CS5:
cval = UART_LCR_WLEN5;
break;
case CS6:
cval = UART_LCR_WLEN6;
break;
case CS7:
cval = UART_LCR_WLEN7;
break;
default:
case CS8:
cval = UART_LCR_WLEN8;
break;
}
/* CMSPAR isn't supported by this driver */
if (tty)
tty->termios->c_cflag &= ~CMSPAR;
if (termios->c_cflag & CSTOPB)
cval |= UART_LCR_STOP;
if (termios->c_cflag & PARENB)
cval |= UART_LCR_PARITY;
if (!(termios->c_cflag & PARODD))
cval |= UART_LCR_EPAR;
/*
* The base clk is 50Mhz, and the baud rate come from:
* baud = 50M * MUL / (DIV * PS * DLAB)
*
* For those basic low baud rate we can get the direct
* scalar from 2746800, like 115200 = 2746800/24. For those
* higher baud rate, we handle them case by case, mainly by
* adjusting the MUL/PS registers, and DIV register is kept
* as default value 0x3d09 to make things simple
*/
baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
quot = 1;
ps = 0x10;
mul = 0x3600;
switch (baud) {
case 3500000:
mul = 0x3345;
ps = 0xC;
break;
case 1843200:
mul = 0x2400;
break;
case 3000000:
case 2500000:
case 2000000:
case 1500000:
case 1000000:
case 500000:
/* mul/ps/quot = 0x9C4/0x10/0x1 will make a 500000 bps */
mul = baud / 500000 * 0x9C4;
break;
default:
/* Use uart_get_divisor to get quot for other baud rates */
quot = 0;
}
if (!quot)
quot = uart_get_divisor(port, baud);
if ((up->port.uartclk / quot) < (2400 * 16))
fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_1B;
else if ((up->port.uartclk / quot) < (230400 * 16))
fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_16B;
else
fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_32B;
fcr |= UART_FCR_HSU_64B_FIFO;
#ifdef MFD_HSU_A0_STEPPING
/* A0 doesn't support half empty IRQ */
fcr |= UART_FCR_FULL_EMPT_TXI;
#endif
/*
* Ok, we're now changing the port state. Do it with
* interrupts disabled.
*/
spin_lock_irqsave(&up->port.lock, flags);
/* Update the per-port timeout */
uart_update_timeout(port, termios->c_cflag, baud);
up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
if (termios->c_iflag & INPCK)
up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
if (termios->c_iflag & (BRKINT | PARMRK))
up->port.read_status_mask |= UART_LSR_BI;
/* Characters to ignore */
up->port.ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
if (termios->c_iflag & IGNBRK) {
up->port.ignore_status_mask |= UART_LSR_BI;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
up->port.ignore_status_mask |= UART_LSR_OE;
}
/* Ignore all characters if CREAD is not set */
if ((termios->c_cflag & CREAD) == 0)
up->port.ignore_status_mask |= UART_LSR_DR;
/*
* CTS flow control flag and modem status interrupts, disable
* MSI by default
*/
up->ier &= ~UART_IER_MSI;
if (UART_ENABLE_MS(&up->port, termios->c_cflag))
up->ier |= UART_IER_MSI;
serial_out(up, UART_IER, up->ier);
if (termios->c_cflag & CRTSCTS)
up->mcr |= UART_MCR_AFE | UART_MCR_RTS;
else
up->mcr &= ~UART_MCR_AFE;
serial_out(up, UART_LCR, cval | UART_LCR_DLAB); /* set DLAB */
serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */
serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */
serial_out(up, UART_LCR, cval); /* reset DLAB */
serial_out(up, UART_MUL, mul); /* set MUL */
serial_out(up, UART_PS, ps); /* set PS */
up->lcr = cval; /* Save LCR */
serial_hsu_set_mctrl(&up->port, up->port.mctrl);
serial_out(up, UART_FCR, fcr);
spin_unlock_irqrestore(&up->port.lock, flags);
}
static void
serial_hsu_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
}
static void serial_hsu_release_port(struct uart_port *port)
{
}
static int serial_hsu_request_port(struct uart_port *port)
{
return 0;
}
static void serial_hsu_config_port(struct uart_port *port, int flags)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
up->port.type = PORT_MFD;
}
static int
serial_hsu_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 const char *
serial_hsu_type(struct uart_port *port)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
return up->name;
}
/* Mainly for uart console use */
static struct uart_hsu_port *serial_hsu_ports[3];
static struct uart_driver serial_hsu_reg;
#ifdef CONFIG_SERIAL_MFD_HSU_CONSOLE
#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
/* Wait for transmitter & holding register to empty */
static inline void wait_for_xmitr(struct uart_hsu_port *up)
{
unsigned int status, tmout = 1000;
/* Wait up to 1ms for the character to be sent. */
do {
status = serial_in(up, UART_LSR);
if (status & UART_LSR_BI)
up->lsr_break_flag = UART_LSR_BI;
if (--tmout == 0)
break;
udelay(1);
} while (!(status & BOTH_EMPTY));
/* Wait up to 1s for flow control if necessary */
if (up->port.flags & UPF_CONS_FLOW) {
tmout = 1000000;
while (--tmout &&
((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
udelay(1);
}
}
static void serial_hsu_console_putchar(struct uart_port *port, int ch)
{
struct uart_hsu_port *up =
container_of(port, struct uart_hsu_port, port);
wait_for_xmitr(up);
serial_out(up, UART_TX, ch);
}
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*
* The console_lock must be held when we get here.
*/
static void
serial_hsu_console_write(struct console *co, const char *s, unsigned int count)
{
struct uart_hsu_port *up = serial_hsu_ports[co->index];
unsigned long flags;
unsigned int ier;
int locked = 1;
local_irq_save(flags);
if (up->port.sysrq)
locked = 0;
else if (oops_in_progress) {
locked = spin_trylock(&up->port.lock);
} else
spin_lock(&up->port.lock);
/* First save the IER then disable the interrupts */
ier = serial_in(up, UART_IER);
serial_out(up, UART_IER, 0);
uart_console_write(&up->port, s, count, serial_hsu_console_putchar);
/*
* Finally, wait for transmitter to become empty
* and restore the IER
*/
wait_for_xmitr(up);
serial_out(up, UART_IER, ier);
if (locked)
spin_unlock(&up->port.lock);
local_irq_restore(flags);
}
static struct console serial_hsu_console;
static int __init
serial_hsu_console_setup(struct console *co, char *options)
{
struct uart_hsu_port *up;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
int ret;
if (co->index == -1 || co->index >= serial_hsu_reg.nr)
co->index = 0;
up = serial_hsu_ports[co->index];
if (!up)
return -ENODEV;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
ret = uart_set_options(&up->port, co, baud, parity, bits, flow);
return ret;
}
static struct console serial_hsu_console = {
.name = "ttyMFD",
.write = serial_hsu_console_write,
.device = uart_console_device,
.setup = serial_hsu_console_setup,
.flags = CON_PRINTBUFFER,
.index = 2,
.data = &serial_hsu_reg,
};
#endif
struct uart_ops serial_hsu_pops = {
.tx_empty = serial_hsu_tx_empty,
.set_mctrl = serial_hsu_set_mctrl,
.get_mctrl = serial_hsu_get_mctrl,
.stop_tx = serial_hsu_stop_tx,
.start_tx = serial_hsu_start_tx,
.stop_rx = serial_hsu_stop_rx,
.enable_ms = serial_hsu_enable_ms,
.break_ctl = serial_hsu_break_ctl,
.startup = serial_hsu_startup,
.shutdown = serial_hsu_shutdown,
.set_termios = serial_hsu_set_termios,
.pm = serial_hsu_pm,
.type = serial_hsu_type,
.release_port = serial_hsu_release_port,
.request_port = serial_hsu_request_port,
.config_port = serial_hsu_config_port,
.verify_port = serial_hsu_verify_port,
};
static struct uart_driver serial_hsu_reg = {
.owner = THIS_MODULE,
.driver_name = "MFD serial",
.dev_name = "ttyMFD",
.major = TTY_MAJOR,
.minor = 128,
.nr = 3,
};
#ifdef CONFIG_PM
static int serial_hsu_suspend(struct pci_dev *pdev, pm_message_t state)
{
void *priv = pci_get_drvdata(pdev);
struct uart_hsu_port *up;
/* Make sure this is not the internal dma controller */
if (priv && (pdev->device != 0x081E)) {
up = priv;
uart_suspend_port(&serial_hsu_reg, &up->port);
}
pci_save_state(pdev);
pci_set_power_state(pdev, pci_choose_state(pdev, state));
return 0;
}
static int serial_hsu_resume(struct pci_dev *pdev)
{
void *priv = pci_get_drvdata(pdev);
struct uart_hsu_port *up;
int ret;
pci_set_power_state(pdev, PCI_D0);
pci_restore_state(pdev);
ret = pci_enable_device(pdev);
if (ret)
dev_warn(&pdev->dev,
"HSU: can't re-enable device, try to continue\n");
if (priv && (pdev->device != 0x081E)) {
up = priv;
uart_resume_port(&serial_hsu_reg, &up->port);
}
return 0;
}
#else
#define serial_hsu_suspend NULL
#define serial_hsu_resume NULL
#endif
/* temp global pointer before we settle down on using one or four PCI dev */
static struct hsu_port *phsu;
static int serial_hsu_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
struct uart_hsu_port *uport;
int index, ret;
printk(KERN_INFO "HSU: found PCI Serial controller(ID: %04x:%04x)\n",
pdev->vendor, pdev->device);
switch (pdev->device) {
case 0x081B:
index = 0;
break;
case 0x081C:
index = 1;
break;
case 0x081D:
index = 2;
break;
case 0x081E:
/* internal DMA controller */
index = 3;
break;
default:
dev_err(&pdev->dev, "HSU: out of index!");
return -ENODEV;
}
ret = pci_enable_device(pdev);
if (ret)
return ret;
if (index == 3) {
/* DMA controller */
ret = request_irq(pdev->irq, dma_irq, 0, "hsu_dma", phsu);
if (ret) {
dev_err(&pdev->dev, "can not get IRQ\n");
goto err_disable;
}
pci_set_drvdata(pdev, phsu);
} else {
/* UART port 0~2 */
uport = &phsu->port[index];
uport->port.irq = pdev->irq;
uport->port.dev = &pdev->dev;
uport->dev = &pdev->dev;
ret = request_irq(pdev->irq, port_irq, 0, uport->name, uport);
if (ret) {
dev_err(&pdev->dev, "can not get IRQ\n");
goto err_disable;
}
uart_add_one_port(&serial_hsu_reg, &uport->port);
#ifdef CONFIG_SERIAL_MFD_HSU_CONSOLE
if (index == 2) {
register_console(&serial_hsu_console);
uport->port.cons = &serial_hsu_console;
}
#endif
pci_set_drvdata(pdev, uport);
}
return 0;
err_disable:
pci_disable_device(pdev);
return ret;
}
static void hsu_global_init(void)
{
struct hsu_port *hsu;
struct uart_hsu_port *uport;
struct hsu_dma_chan *dchan;
int i, ret;
hsu = kzalloc(sizeof(struct hsu_port), GFP_KERNEL);
if (!hsu)
return;
/* Get basic io resource and map it */
hsu->paddr = 0xffa28000;
hsu->iolen = 0x1000;
if (!(request_mem_region(hsu->paddr, hsu->iolen, "HSU global")))
pr_warning("HSU: error in request mem region\n");
hsu->reg = ioremap_nocache((unsigned long)hsu->paddr, hsu->iolen);
if (!hsu->reg) {
pr_err("HSU: error in ioremap\n");
ret = -ENOMEM;
goto err_free_region;
}
/* Initialise the 3 UART ports */
uport = hsu->port;
for (i = 0; i < 3; i++) {
uport->port.type = PORT_MFD;
uport->port.iotype = UPIO_MEM;
uport->port.mapbase = (resource_size_t)hsu->paddr
+ HSU_PORT_REG_OFFSET
+ i * HSU_PORT_REG_LENGTH;
uport->port.membase = hsu->reg + HSU_PORT_REG_OFFSET
+ i * HSU_PORT_REG_LENGTH;
sprintf(uport->name, "hsu_port%d", i);
uport->port.fifosize = 64;
uport->port.ops = &serial_hsu_pops;
uport->port.line = i;
uport->port.flags = UPF_IOREMAP;
/* set the scalable maxim support rate to 2746800 bps */
uport->port.uartclk = 115200 * 24 * 16;
uport->running = 0;
uport->txc = &hsu->chans[i * 2];
uport->rxc = &hsu->chans[i * 2 + 1];
serial_hsu_ports[i] = uport;
uport->index = i;
uport++;
}
/* Initialise 6 dma channels */
dchan = hsu->chans;
for (i = 0; i < 6; i++) {
dchan->id = i;
dchan->dirt = (i & 0x1) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
dchan->uport = &hsu->port[i/2];
dchan->reg = hsu->reg + HSU_DMA_CHANS_REG_OFFSET +
i * HSU_DMA_CHANS_REG_LENGTH;
dchan++;
}
phsu = hsu;
hsu_debugfs_init(hsu);
return;
err_free_region:
release_mem_region(hsu->paddr, hsu->iolen);
kfree(hsu);
return;
}
static void serial_hsu_remove(struct pci_dev *pdev)
{
void *priv = pci_get_drvdata(pdev);
struct uart_hsu_port *up;
if (!priv)
return;
/* For port 0/1/2, priv is the address of uart_hsu_port */
if (pdev->device != 0x081E) {
up = priv;
uart_remove_one_port(&serial_hsu_reg, &up->port);
}
pci_set_drvdata(pdev, NULL);
free_irq(pdev->irq, priv);
pci_disable_device(pdev);
}
/* First 3 are UART ports, and the 4th is the DMA */
static const struct pci_device_id pci_ids[] __devinitdata = {
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081B) },
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081C) },
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081D) },
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081E) },
{},
};
static struct pci_driver hsu_pci_driver = {
.name = "HSU serial",
.id_table = pci_ids,
.probe = serial_hsu_probe,
.remove = __devexit_p(serial_hsu_remove),
.suspend = serial_hsu_suspend,
.resume = serial_hsu_resume,
};
static int __init hsu_pci_init(void)
{
int ret;
hsu_global_init();
ret = uart_register_driver(&serial_hsu_reg);
if (ret)
return ret;
return pci_register_driver(&hsu_pci_driver);
}
static void __exit hsu_pci_exit(void)
{
pci_unregister_driver(&hsu_pci_driver);
uart_unregister_driver(&serial_hsu_reg);
hsu_debugfs_remove(phsu);
kfree(phsu);
}
module_init(hsu_pci_init);
module_exit(hsu_pci_exit);
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:medfield-hsu");
Reference in a new issue View git blame Copy permalink