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linux-sg2042/drivers/tty/serial/lantiq.c

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/*
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Copyright (C) 2004 Infineon IFAP DC COM CPE
* Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
* Copyright (C) 2007 John Crispin <blogic@openwrt.org>
* Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/gpio.h>
#include <lantiq_soc.h>
#define PORT_LTQ_ASC 111
#define MAXPORTS 2
#define UART_DUMMY_UER_RX 1
#define DRVNAME "lantiq,asc"
#ifdef __BIG_ENDIAN
#define LTQ_ASC_TBUF (0x0020 + 3)
#define LTQ_ASC_RBUF (0x0024 + 3)
#else
#define LTQ_ASC_TBUF 0x0020
#define LTQ_ASC_RBUF 0x0024
#endif
#define LTQ_ASC_FSTAT 0x0048
#define LTQ_ASC_WHBSTATE 0x0018
#define LTQ_ASC_STATE 0x0014
#define LTQ_ASC_IRNCR 0x00F8
#define LTQ_ASC_CLC 0x0000
#define LTQ_ASC_ID 0x0008
#define LTQ_ASC_PISEL 0x0004
#define LTQ_ASC_TXFCON 0x0044
#define LTQ_ASC_RXFCON 0x0040
#define LTQ_ASC_CON 0x0010
#define LTQ_ASC_BG 0x0050
#define LTQ_ASC_IRNREN 0x00F4
#define ASC_IRNREN_TX 0x1
#define ASC_IRNREN_RX 0x2
#define ASC_IRNREN_ERR 0x4
#define ASC_IRNREN_TX_BUF 0x8
#define ASC_IRNCR_TIR 0x1
#define ASC_IRNCR_RIR 0x2
#define ASC_IRNCR_EIR 0x4
#define ASCOPT_CSIZE 0x3
#define TXFIFO_FL 1
#define RXFIFO_FL 1
#define ASCCLC_DISS 0x2
#define ASCCLC_RMCMASK 0x0000FF00
#define ASCCLC_RMCOFFSET 8
#define ASCCON_M_8ASYNC 0x0
#define ASCCON_M_7ASYNC 0x2
#define ASCCON_ODD 0x00000020
#define ASCCON_STP 0x00000080
#define ASCCON_BRS 0x00000100
#define ASCCON_FDE 0x00000200
#define ASCCON_R 0x00008000
#define ASCCON_FEN 0x00020000
#define ASCCON_ROEN 0x00080000
#define ASCCON_TOEN 0x00100000
#define ASCSTATE_PE 0x00010000
#define ASCSTATE_FE 0x00020000
#define ASCSTATE_ROE 0x00080000
#define ASCSTATE_ANY (ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
#define ASCWHBSTATE_CLRREN 0x00000001
#define ASCWHBSTATE_SETREN 0x00000002
#define ASCWHBSTATE_CLRPE 0x00000004
#define ASCWHBSTATE_CLRFE 0x00000008
#define ASCWHBSTATE_CLRROE 0x00000020
#define ASCTXFCON_TXFEN 0x0001
#define ASCTXFCON_TXFFLU 0x0002
#define ASCTXFCON_TXFITLMASK 0x3F00
#define ASCTXFCON_TXFITLOFF 8
#define ASCRXFCON_RXFEN 0x0001
#define ASCRXFCON_RXFFLU 0x0002
#define ASCRXFCON_RXFITLMASK 0x3F00
#define ASCRXFCON_RXFITLOFF 8
#define ASCFSTAT_RXFFLMASK 0x003F
#define ASCFSTAT_TXFFLMASK 0x3F00
#define ASCFSTAT_TXFREEMASK 0x3F000000
#define ASCFSTAT_TXFREEOFF 24
static void lqasc_tx_chars(struct uart_port *port);
static struct ltq_uart_port *lqasc_port[MAXPORTS];
static struct uart_driver lqasc_reg;
static DEFINE_SPINLOCK(ltq_asc_lock);
struct ltq_uart_port {
struct uart_port port;
/* clock used to derive divider */
struct clk *fpiclk;
/* clock gating of the ASC core */
struct clk *clk;
unsigned int tx_irq;
unsigned int rx_irq;
unsigned int err_irq;
};
static inline struct
ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
{
return container_of(port, struct ltq_uart_port, port);
}
static void
lqasc_stop_tx(struct uart_port *port)
{
return;
}
static void
lqasc_start_tx(struct uart_port *port)
{
unsigned long flags;
spin_lock_irqsave(&ltq_asc_lock, flags);
lqasc_tx_chars(port);
spin_unlock_irqrestore(&ltq_asc_lock, flags);
return;
}
static void
lqasc_stop_rx(struct uart_port *port)
{
ltq_w32(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
}
static void
lqasc_enable_ms(struct uart_port *port)
{
}
static int
lqasc_rx_chars(struct uart_port *port)
{
struct tty_port *tport = &port->state->port;
unsigned int ch = 0, rsr = 0, fifocnt;
fifocnt = ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_RXFFLMASK;
while (fifocnt--) {
u8 flag = TTY_NORMAL;
ch = ltq_r8(port->membase + LTQ_ASC_RBUF);
rsr = (ltq_r32(port->membase + LTQ_ASC_STATE)
& ASCSTATE_ANY) | UART_DUMMY_UER_RX;
tty_flip_buffer_push(tport);
port->icount.rx++;
/*
* Note that the error handling code is
* out of the main execution path
*/
if (rsr & ASCSTATE_ANY) {
if (rsr & ASCSTATE_PE) {
port->icount.parity++;
ltq_w32_mask(0, ASCWHBSTATE_CLRPE,
port->membase + LTQ_ASC_WHBSTATE);
} else if (rsr & ASCSTATE_FE) {
port->icount.frame++;
ltq_w32_mask(0, ASCWHBSTATE_CLRFE,
port->membase + LTQ_ASC_WHBSTATE);
}
if (rsr & ASCSTATE_ROE) {
port->icount.overrun++;
ltq_w32_mask(0, ASCWHBSTATE_CLRROE,
port->membase + LTQ_ASC_WHBSTATE);
}
rsr &= port->read_status_mask;
if (rsr & ASCSTATE_PE)
flag = TTY_PARITY;
else if (rsr & ASCSTATE_FE)
flag = TTY_FRAME;
}
if ((rsr & port->ignore_status_mask) == 0)
tty_insert_flip_char(tport, ch, flag);
if (rsr & ASCSTATE_ROE)
/*
* Overrun is special, since it's reported
* immediately, and doesn't affect the current
* character
*/
tty_insert_flip_char(tport, 0, TTY_OVERRUN);
}
if (ch != 0)
tty_flip_buffer_push(tport);
return 0;
}
static void
lqasc_tx_chars(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
if (uart_tx_stopped(port)) {
lqasc_stop_tx(port);
return;
}
while (((ltq_r32(port->membase + LTQ_ASC_FSTAT) &
ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF) != 0) {
if (port->x_char) {
ltq_w8(port->x_char, port->membase + LTQ_ASC_TBUF);
port->icount.tx++;
port->x_char = 0;
continue;
}
if (uart_circ_empty(xmit))
break;
ltq_w8(port->state->xmit.buf[port->state->xmit.tail],
port->membase + LTQ_ASC_TBUF);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
}
static irqreturn_t
lqasc_tx_int(int irq, void *_port)
{
unsigned long flags;
struct uart_port *port = (struct uart_port *)_port;
spin_lock_irqsave(&ltq_asc_lock, flags);
ltq_w32(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
spin_unlock_irqrestore(&ltq_asc_lock, flags);
lqasc_start_tx(port);
return IRQ_HANDLED;
}
static irqreturn_t
lqasc_err_int(int irq, void *_port)
{
unsigned long flags;
struct uart_port *port = (struct uart_port *)_port;
spin_lock_irqsave(&ltq_asc_lock, flags);
/* clear any pending interrupts */
ltq_w32_mask(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
spin_unlock_irqrestore(&ltq_asc_lock, flags);
return IRQ_HANDLED;
}
static irqreturn_t
lqasc_rx_int(int irq, void *_port)
{
unsigned long flags;
struct uart_port *port = (struct uart_port *)_port;
spin_lock_irqsave(&ltq_asc_lock, flags);
ltq_w32(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
lqasc_rx_chars(port);
spin_unlock_irqrestore(&ltq_asc_lock, flags);
return IRQ_HANDLED;
}
static unsigned int
lqasc_tx_empty(struct uart_port *port)
{
int status;
status = ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_TXFFLMASK;
return status ? 0 : TIOCSER_TEMT;
}
static unsigned int
lqasc_get_mctrl(struct uart_port *port)
{
return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR;
}
static void
lqasc_set_mctrl(struct uart_port *port, u_int mctrl)
{
}
static void
lqasc_break_ctl(struct uart_port *port, int break_state)
{
}
static int
lqasc_startup(struct uart_port *port)
{
struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
int retval;
if (ltq_port->clk)
clk_enable(ltq_port->clk);
port->uartclk = clk_get_rate(ltq_port->fpiclk);
ltq_w32_mask(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
port->membase + LTQ_ASC_CLC);
ltq_w32(0, port->membase + LTQ_ASC_PISEL);
ltq_w32(
((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
port->membase + LTQ_ASC_TXFCON);
ltq_w32(
((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
| ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
port->membase + LTQ_ASC_RXFCON);
/* make sure other settings are written to hardware before
* setting enable bits
*/
wmb();
ltq_w32_mask(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
ASCCON_ROEN, port->membase + LTQ_ASC_CON);
retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
0, "asc_tx", port);
if (retval) {
pr_err("failed to request lqasc_tx_int\n");
return retval;
}
retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
0, "asc_rx", port);
if (retval) {
pr_err("failed to request lqasc_rx_int\n");
goto err1;
}
retval = request_irq(ltq_port->err_irq, lqasc_err_int,
0, "asc_err", port);
if (retval) {
pr_err("failed to request lqasc_err_int\n");
goto err2;
}
ltq_w32(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
port->membase + LTQ_ASC_IRNREN);
return 0;
err2:
free_irq(ltq_port->rx_irq, port);
err1:
free_irq(ltq_port->tx_irq, port);
return retval;
}
static void
lqasc_shutdown(struct uart_port *port)
{
struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
free_irq(ltq_port->tx_irq, port);
free_irq(ltq_port->rx_irq, port);
free_irq(ltq_port->err_irq, port);
ltq_w32(0, port->membase + LTQ_ASC_CON);
ltq_w32_mask(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
port->membase + LTQ_ASC_RXFCON);
ltq_w32_mask(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
port->membase + LTQ_ASC_TXFCON);
if (ltq_port->clk)
clk_disable(ltq_port->clk);
}
static void
lqasc_set_termios(struct uart_port *port,
struct ktermios *new, struct ktermios *old)
{
unsigned int cflag;
unsigned int iflag;
unsigned int divisor;
unsigned int baud;
unsigned int con = 0;
unsigned long flags;
cflag = new->c_cflag;
iflag = new->c_iflag;
switch (cflag & CSIZE) {
case CS7:
con = ASCCON_M_7ASYNC;
break;
case CS5:
case CS6:
default:
new->c_cflag &= ~ CSIZE;
new->c_cflag |= CS8;
con = ASCCON_M_8ASYNC;
break;
}
cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
if (cflag & CSTOPB)
con |= ASCCON_STP;
if (cflag & PARENB) {
if (!(cflag & PARODD))
con &= ~ASCCON_ODD;
else
con |= ASCCON_ODD;
}
port->read_status_mask = ASCSTATE_ROE;
if (iflag & INPCK)
port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
port->ignore_status_mask = 0;
if (iflag & IGNPAR)
port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
if (iflag & IGNBRK) {
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (iflag & IGNPAR)
port->ignore_status_mask |= ASCSTATE_ROE;
}
if ((cflag & CREAD) == 0)
port->ignore_status_mask |= UART_DUMMY_UER_RX;
/* set error signals - framing, parity and overrun, enable receiver */
con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
spin_lock_irqsave(&ltq_asc_lock, flags);
/* set up CON */
ltq_w32_mask(0, con, port->membase + LTQ_ASC_CON);
/* Set baud rate - take a divider of 2 into account */
baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
divisor = uart_get_divisor(port, baud);
divisor = divisor / 2 - 1;
/* disable the baudrate generator */
ltq_w32_mask(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
/* make sure the fractional divider is off */
ltq_w32_mask(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
/* set up to use divisor of 2 */
ltq_w32_mask(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
/* now we can write the new baudrate into the register */
ltq_w32(divisor, port->membase + LTQ_ASC_BG);
/* turn the baudrate generator back on */
ltq_w32_mask(0, ASCCON_R, port->membase + LTQ_ASC_CON);
/* enable rx */
ltq_w32(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
spin_unlock_irqrestore(&ltq_asc_lock, flags);
/* Don't rewrite B0 */
if (tty_termios_baud_rate(new))
tty_termios_encode_baud_rate(new, baud, baud);
uart_update_timeout(port, cflag, baud);
}
static const char*
lqasc_type(struct uart_port *port)
{
if (port->type == PORT_LTQ_ASC)
return DRVNAME;
else
return NULL;
}
static void
lqasc_release_port(struct uart_port *port)
{
if (port->flags & UPF_IOREMAP) {
iounmap(port->membase);
port->membase = NULL;
}
}
static int
lqasc_request_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
struct resource *res;
int size;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "cannot obtain I/O memory region");
return -ENODEV;
}
size = resource_size(res);
res = devm_request_mem_region(&pdev->dev, res->start,
size, dev_name(&pdev->dev));
if (!res) {
dev_err(&pdev->dev, "cannot request I/O memory region");
return -EBUSY;
}
if (port->flags & UPF_IOREMAP) {
port->membase = devm_ioremap_nocache(&pdev->dev,
port->mapbase, size);
if (port->membase == NULL)
return -ENOMEM;
}
return 0;
}
static void
lqasc_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE) {
port->type = PORT_LTQ_ASC;
lqasc_request_port(port);
}
}
static int
lqasc_verify_port(struct uart_port *port,
struct serial_struct *ser)
{
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC)
ret = -EINVAL;
if (ser->irq < 0 || ser->irq >= NR_IRQS)
ret = -EINVAL;
if (ser->baud_base < 9600)
ret = -EINVAL;
return ret;
}
static struct uart_ops lqasc_pops = {
.tx_empty = lqasc_tx_empty,
.set_mctrl = lqasc_set_mctrl,
.get_mctrl = lqasc_get_mctrl,
.stop_tx = lqasc_stop_tx,
.start_tx = lqasc_start_tx,
.stop_rx = lqasc_stop_rx,
.enable_ms = lqasc_enable_ms,
.break_ctl = lqasc_break_ctl,
.startup = lqasc_startup,
.shutdown = lqasc_shutdown,
.set_termios = lqasc_set_termios,
.type = lqasc_type,
.release_port = lqasc_release_port,
.request_port = lqasc_request_port,
.config_port = lqasc_config_port,
.verify_port = lqasc_verify_port,
};
static void
lqasc_console_putchar(struct uart_port *port, int ch)
{
int fifofree;
if (!port->membase)
return;
do {
fifofree = (ltq_r32(port->membase + LTQ_ASC_FSTAT)
& ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF;
} while (fifofree == 0);
ltq_w8(ch, port->membase + LTQ_ASC_TBUF);
}
static void
lqasc_console_write(struct console *co, const char *s, u_int count)
{
struct ltq_uart_port *ltq_port;
struct uart_port *port;
unsigned long flags;
if (co->index >= MAXPORTS)
return;
ltq_port = lqasc_port[co->index];
if (!ltq_port)
return;
port = &ltq_port->port;
spin_lock_irqsave(&ltq_asc_lock, flags);
uart_console_write(port, s, count, lqasc_console_putchar);
spin_unlock_irqrestore(&ltq_asc_lock, flags);
}
static int __init
lqasc_console_setup(struct console *co, char *options)
{
struct ltq_uart_port *ltq_port;
struct uart_port *port;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (co->index >= MAXPORTS)
return -ENODEV;
ltq_port = lqasc_port[co->index];
if (!ltq_port)
return -ENODEV;
port = &ltq_port->port;
port->uartclk = clk_get_rate(ltq_port->fpiclk);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct console lqasc_console = {
.name = "ttyLTQ",
.write = lqasc_console_write,
.device = uart_console_device,
.setup = lqasc_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &lqasc_reg,
};
static int __init
lqasc_console_init(void)
{
register_console(&lqasc_console);
return 0;
}
console_initcall(lqasc_console_init);
static struct uart_driver lqasc_reg = {
.owner = THIS_MODULE,
.driver_name = DRVNAME,
.dev_name = "ttyLTQ",
.major = 0,
.minor = 0,
.nr = MAXPORTS,
.cons = &lqasc_console,
};
static int __init
lqasc_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
struct ltq_uart_port *ltq_port;
struct uart_port *port;
struct resource *mmres, irqres[3];
int line = 0;
int ret;
mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
ret = of_irq_to_resource_table(node, irqres, 3);
if (!mmres || (ret != 3)) {
dev_err(&pdev->dev,
"failed to get memory/irq for serial port\n");
return -ENODEV;
}
/* check if this is the console port */
if (mmres->start != CPHYSADDR(LTQ_EARLY_ASC))
line = 1;
if (lqasc_port[line]) {
dev_err(&pdev->dev, "port %d already allocated\n", line);
return -EBUSY;
}
ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
GFP_KERNEL);
if (!ltq_port)
return -ENOMEM;
port = &ltq_port->port;
port->iotype = SERIAL_IO_MEM;
port->flags = ASYNC_BOOT_AUTOCONF | UPF_IOREMAP;
port->ops = &lqasc_pops;
port->fifosize = 16;
port->type = PORT_LTQ_ASC,
port->line = line;
port->dev = &pdev->dev;
/* unused, just to be backward-compatible */
port->irq = irqres[0].start;
port->mapbase = mmres->start;
ltq_port->fpiclk = clk_get_fpi();
if (IS_ERR(ltq_port->fpiclk)) {
pr_err("failed to get fpi clk\n");
return -ENOENT;
}
/* not all asc ports have clock gates, lets ignore the return code */
ltq_port->clk = clk_get(&pdev->dev, NULL);
ltq_port->tx_irq = irqres[0].start;
ltq_port->rx_irq = irqres[1].start;
ltq_port->err_irq = irqres[2].start;
lqasc_port[line] = ltq_port;
platform_set_drvdata(pdev, ltq_port);
ret = uart_add_one_port(&lqasc_reg, port);
return ret;
}
static const struct of_device_id ltq_asc_match[] = {
{ .compatible = DRVNAME },
{},
};
MODULE_DEVICE_TABLE(of, ltq_asc_match);
static struct platform_driver lqasc_driver = {
.driver = {
.name = DRVNAME,
.owner = THIS_MODULE,
.of_match_table = ltq_asc_match,
},
};
int __init
init_lqasc(void)
{
int ret;
ret = uart_register_driver(&lqasc_reg);
if (ret != 0)
return ret;
ret = platform_driver_probe(&lqasc_driver, lqasc_probe);
if (ret != 0)
uart_unregister_driver(&lqasc_reg);
return ret;
}
module_init(init_lqasc);
MODULE_DESCRIPTION("Lantiq serial port driver");
MODULE_LICENSE("GPL");
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