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mfd.c
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/*
* 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/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)
#define HSU_DMA_TIMEOUT_CHECK_FREQ (HZ/10)
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 timer_list rx_timer; /* only needed by RX channel */
};
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));
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));
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,
};
static const struct file_operations dma_regs_ops = {
.owner = THIS_MODULE,
.open = hsu_show_regs_open,
.read = dma_show_regs,
};
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);
mod_timer(&rxc->rx_timer, jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ);
}
/* 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;
}
del_timer(&chan->rx_timer);
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);
chan->rx_timer.expires = jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ;
add_timer(&chan->rx_timer);
}
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;
del_timer_sync(&up->rxc->rx_timer);
/* 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 mul = 0x3600;
u32 ps = 0x10;
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;
/*
* For those basic low baud rate we can get the direct
* scalar from 2746800, like 115200 = 2746800/24, for those
* higher baud rate, we have to handle them case by case,
* but DIV reg is never touched as its default value 0x3d09
*/
baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
quot = uart_get_divisor(port, baud);
switch (baud) {
case 3500000:
mul = 0x3345;
ps = 0xC;
quot = 1;
break;
case 2500000:
mul = 0x2710;
ps = 0x10;
quot = 1;
break;
case 18432000:
mul = 0x2400;
ps = 0x10;
quot = 1;
break;
case 1500000:
mul = 0x1D4C;
ps = 0xc;
quot = 1;
break;
default:
;
}
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 */