android_kernel_xiaomi_sm8350/drivers/serial/netx-serial.c
Jeff Garzik c7bec5aba5 Various drivers' irq handlers: kill dead code, needless casts
- Eliminate casts to/from void*

- Eliminate checks for conditions that never occur.  These typically
  fall into two classes:

	1) Checking for 'dev_id == NULL', then it is never called with
	NULL as an argument.

	2) Checking for invalid irq number, when the only caller (the
	system) guarantees the irq handler is called with the proper
	'irq' number argument.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-10-06 15:00:58 -04:00

748 lines
17 KiB
C

/*
* drivers/serial/netx-serial.c
*
* Copyright (c) 2005 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
*
* 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
*/
#if defined(CONFIG_SERIAL_NETX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/device.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/platform_device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/hardware.h>
#include <asm/arch/netx-regs.h>
/* We've been assigned a range on the "Low-density serial ports" major */
#define SERIAL_NX_MAJOR 204
#define MINOR_START 170
#ifdef CONFIG_SERIAL_NETX_CONSOLE
enum uart_regs {
UART_DR = 0x00,
UART_SR = 0x04,
UART_LINE_CR = 0x08,
UART_BAUDDIV_MSB = 0x0c,
UART_BAUDDIV_LSB = 0x10,
UART_CR = 0x14,
UART_FR = 0x18,
UART_IIR = 0x1c,
UART_ILPR = 0x20,
UART_RTS_CR = 0x24,
UART_RTS_LEAD = 0x28,
UART_RTS_TRAIL = 0x2c,
UART_DRV_ENABLE = 0x30,
UART_BRM_CR = 0x34,
UART_RXFIFO_IRQLEVEL = 0x38,
UART_TXFIFO_IRQLEVEL = 0x3c,
};
#define SR_FE (1<<0)
#define SR_PE (1<<1)
#define SR_BE (1<<2)
#define SR_OE (1<<3)
#define LINE_CR_BRK (1<<0)
#define LINE_CR_PEN (1<<1)
#define LINE_CR_EPS (1<<2)
#define LINE_CR_STP2 (1<<3)
#define LINE_CR_FEN (1<<4)
#define LINE_CR_5BIT (0<<5)
#define LINE_CR_6BIT (1<<5)
#define LINE_CR_7BIT (2<<5)
#define LINE_CR_8BIT (3<<5)
#define LINE_CR_BITS_MASK (3<<5)
#define CR_UART_EN (1<<0)
#define CR_SIREN (1<<1)
#define CR_SIRLP (1<<2)
#define CR_MSIE (1<<3)
#define CR_RIE (1<<4)
#define CR_TIE (1<<5)
#define CR_RTIE (1<<6)
#define CR_LBE (1<<7)
#define FR_CTS (1<<0)
#define FR_DSR (1<<1)
#define FR_DCD (1<<2)
#define FR_BUSY (1<<3)
#define FR_RXFE (1<<4)
#define FR_TXFF (1<<5)
#define FR_RXFF (1<<6)
#define FR_TXFE (1<<7)
#define IIR_MIS (1<<0)
#define IIR_RIS (1<<1)
#define IIR_TIS (1<<2)
#define IIR_RTIS (1<<3)
#define IIR_MASK 0xf
#define RTS_CR_AUTO (1<<0)
#define RTS_CR_RTS (1<<1)
#define RTS_CR_COUNT (1<<2)
#define RTS_CR_MOD2 (1<<3)
#define RTS_CR_RTS_POL (1<<4)
#define RTS_CR_CTS_CTR (1<<5)
#define RTS_CR_CTS_POL (1<<6)
#define RTS_CR_STICK (1<<7)
#define UART_PORT_SIZE 0x40
#define DRIVER_NAME "netx-uart"
struct netx_port {
struct uart_port port;
};
static void netx_stop_tx(struct uart_port *port)
{
unsigned int val;
val = readl(port->membase + UART_CR);
writel(val & ~CR_TIE, port->membase + UART_CR);
}
static void netx_stop_rx(struct uart_port *port)
{
unsigned int val;
val = readl(port->membase + UART_CR);
writel(val & ~CR_RIE, port->membase + UART_CR);
}
static void netx_enable_ms(struct uart_port *port)
{
unsigned int val;
val = readl(port->membase + UART_CR);
writel(val | CR_MSIE, port->membase + UART_CR);
}
static inline void netx_transmit_buffer(struct uart_port *port)
{
struct circ_buf *xmit = &port->info->xmit;
if (port->x_char) {
writel(port->x_char, port->membase + UART_DR);
port->icount.tx++;
port->x_char = 0;
return;
}
if (uart_tx_stopped(port) || uart_circ_empty(xmit)) {
netx_stop_tx(port);
return;
}
do {
/* send xmit->buf[xmit->tail]
* out the port here */
writel(xmit->buf[xmit->tail], port->membase + UART_DR);
xmit->tail = (xmit->tail + 1) &
(UART_XMIT_SIZE - 1);
port->icount.tx++;
if (uart_circ_empty(xmit))
break;
} while (!(readl(port->membase + UART_FR) & FR_TXFF));
if (uart_circ_empty(xmit))
netx_stop_tx(port);
}
static void netx_start_tx(struct uart_port *port)
{
writel(
readl(port->membase + UART_CR) | CR_TIE, port->membase + UART_CR);
if (!(readl(port->membase + UART_FR) & FR_TXFF))
netx_transmit_buffer(port);
}
static unsigned int netx_tx_empty(struct uart_port *port)
{
return readl(port->membase + UART_FR) & FR_BUSY ? 0 : TIOCSER_TEMT;
}
static void netx_txint(struct uart_port *port)
{
struct circ_buf *xmit = &port->info->xmit;
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
netx_stop_tx(port);
return;
}
netx_transmit_buffer(port);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
}
static void netx_rxint(struct uart_port *port)
{
unsigned char rx, flg, status;
struct tty_struct *tty = port->info->tty;
while (!(readl(port->membase + UART_FR) & FR_RXFE)) {
rx = readl(port->membase + UART_DR);
flg = TTY_NORMAL;
port->icount.rx++;
status = readl(port->membase + UART_SR);
if (status & SR_BE) {
writel(0, port->membase + UART_SR);
if (uart_handle_break(port))
continue;
}
if (unlikely(status & (SR_FE | SR_PE | SR_OE))) {
if (status & SR_PE)
port->icount.parity++;
else if (status & SR_FE)
port->icount.frame++;
if (status & SR_OE)
port->icount.overrun++;
status &= port->read_status_mask;
if (status & SR_BE)
flg = TTY_BREAK;
else if (status & SR_PE)
flg = TTY_PARITY;
else if (status & SR_FE)
flg = TTY_FRAME;
}
if (uart_handle_sysrq_char(port, rx))
continue;
uart_insert_char(port, status, SR_OE, rx, flg);
}
tty_flip_buffer_push(tty);
return;
}
static irqreturn_t netx_int(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
unsigned long flags;
unsigned char status;
spin_lock_irqsave(&port->lock,flags);
status = readl(port->membase + UART_IIR) & IIR_MASK;
while (status) {
if (status & IIR_RIS)
netx_rxint(port);
if (status & IIR_TIS)
netx_txint(port);
if (status & IIR_MIS) {
if (readl(port->membase + UART_FR) & FR_CTS)
uart_handle_cts_change(port, 1);
else
uart_handle_cts_change(port, 0);
}
writel(0, port->membase + UART_IIR);
status = readl(port->membase + UART_IIR) & IIR_MASK;
}
spin_unlock_irqrestore(&port->lock,flags);
return IRQ_HANDLED;
}
static unsigned int netx_get_mctrl(struct uart_port *port)
{
unsigned int ret = TIOCM_DSR | TIOCM_CAR;
if (readl(port->membase + UART_FR) & FR_CTS)
ret |= TIOCM_CTS;
return ret;
}
static void netx_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
unsigned int val;
if (mctrl & TIOCM_RTS) {
val = readl(port->membase + UART_RTS_CR);
writel(val | RTS_CR_RTS, port->membase + UART_RTS_CR);
}
}
static void netx_break_ctl(struct uart_port *port, int break_state)
{
unsigned int line_cr;
spin_lock_irq(&port->lock);
line_cr = readl(port->membase + UART_LINE_CR);
if (break_state != 0)
line_cr |= LINE_CR_BRK;
else
line_cr &= ~LINE_CR_BRK;
writel(line_cr, port->membase + UART_LINE_CR);
spin_unlock_irq(&port->lock);
}
static int netx_startup(struct uart_port *port)
{
int ret;
ret = request_irq(port->irq, netx_int, 0,
DRIVER_NAME, port);
if (ret) {
dev_err(port->dev, "unable to grab irq%d\n",port->irq);
goto exit;
}
writel(readl(port->membase + UART_LINE_CR) | LINE_CR_FEN,
port->membase + UART_LINE_CR);
writel(CR_MSIE | CR_RIE | CR_TIE | CR_RTIE | CR_UART_EN,
port->membase + UART_CR);
exit:
return ret;
}
static void netx_shutdown(struct uart_port *port)
{
writel(0, port->membase + UART_CR) ;
free_irq(port->irq, port);
}
static void
netx_set_termios(struct uart_port *port, struct termios *termios,
struct termios *old)
{
unsigned int baud, quot;
unsigned char old_cr;
unsigned char line_cr = LINE_CR_FEN;
unsigned char rts_cr = 0;
switch (termios->c_cflag & CSIZE) {
case CS5:
line_cr |= LINE_CR_5BIT;
break;
case CS6:
line_cr |= LINE_CR_6BIT;
break;
case CS7:
line_cr |= LINE_CR_7BIT;
break;
case CS8:
line_cr |= LINE_CR_8BIT;
break;
}
if (termios->c_cflag & CSTOPB)
line_cr |= LINE_CR_STP2;
if (termios->c_cflag & PARENB) {
line_cr |= LINE_CR_PEN;
if (!(termios->c_cflag & PARODD))
line_cr |= LINE_CR_EPS;
}
if (termios->c_cflag & CRTSCTS)
rts_cr = RTS_CR_AUTO | RTS_CR_CTS_CTR | RTS_CR_RTS_POL;
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
quot = baud * 4096;
quot /= 1000;
quot *= 256;
quot /= 100000;
spin_lock_irq(&port->lock);
uart_update_timeout(port, termios->c_cflag, baud);
old_cr = readl(port->membase + UART_CR);
/* disable interrupts */
writel(old_cr & ~(CR_MSIE | CR_RIE | CR_TIE | CR_RTIE),
port->membase + UART_CR);
/* drain transmitter */
while (readl(port->membase + UART_FR) & FR_BUSY);
/* disable UART */
writel(old_cr & ~CR_UART_EN, port->membase + UART_CR);
/* modem status interrupts */
old_cr &= ~CR_MSIE;
if (UART_ENABLE_MS(port, termios->c_cflag))
old_cr |= CR_MSIE;
writel((quot>>8) & 0xff, port->membase + UART_BAUDDIV_MSB);
writel(quot & 0xff, port->membase + UART_BAUDDIV_LSB);
writel(line_cr, port->membase + UART_LINE_CR);
writel(rts_cr, port->membase + UART_RTS_CR);
/*
* Characters to ignore
*/
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= SR_PE;
if (termios->c_iflag & IGNBRK) {
port->ignore_status_mask |= SR_BE;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= SR_PE;
}
port->read_status_mask = 0;
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= SR_BE;
if (termios->c_iflag & INPCK)
port->read_status_mask |= SR_PE | SR_FE;
writel(old_cr, port->membase + UART_CR);
spin_unlock_irq(&port->lock);
}
static const char *netx_type(struct uart_port *port)
{
return port->type == PORT_NETX ? "NETX" : NULL;
}
static void netx_release_port(struct uart_port *port)
{
release_mem_region(port->mapbase, UART_PORT_SIZE);
}
static int netx_request_port(struct uart_port *port)
{
return request_mem_region(port->mapbase, UART_PORT_SIZE,
DRIVER_NAME) != NULL ? 0 : -EBUSY;
}
static void netx_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE && netx_request_port(port) == 0)
port->type = PORT_NETX;
}
static int
netx_verify_port(struct uart_port *port, struct serial_struct *ser)
{
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_NETX)
ret = -EINVAL;
return ret;
}
static struct uart_ops netx_pops = {
.tx_empty = netx_tx_empty,
.set_mctrl = netx_set_mctrl,
.get_mctrl = netx_get_mctrl,
.stop_tx = netx_stop_tx,
.start_tx = netx_start_tx,
.stop_rx = netx_stop_rx,
.enable_ms = netx_enable_ms,
.break_ctl = netx_break_ctl,
.startup = netx_startup,
.shutdown = netx_shutdown,
.set_termios = netx_set_termios,
.type = netx_type,
.release_port = netx_release_port,
.request_port = netx_request_port,
.config_port = netx_config_port,
.verify_port = netx_verify_port,
};
static struct netx_port netx_ports[] = {
{
.port = {
.type = PORT_NETX,
.iotype = UPIO_MEM,
.membase = (char __iomem *)io_p2v(NETX_PA_UART0),
.mapbase = NETX_PA_UART0,
.irq = NETX_IRQ_UART0,
.uartclk = 100000000,
.fifosize = 16,
.flags = UPF_BOOT_AUTOCONF,
.ops = &netx_pops,
.line = 0,
},
}, {
.port = {
.type = PORT_NETX,
.iotype = UPIO_MEM,
.membase = (char __iomem *)io_p2v(NETX_PA_UART1),
.mapbase = NETX_PA_UART1,
.irq = NETX_IRQ_UART1,
.uartclk = 100000000,
.fifosize = 16,
.flags = UPF_BOOT_AUTOCONF,
.ops = &netx_pops,
.line = 1,
},
}, {
.port = {
.type = PORT_NETX,
.iotype = UPIO_MEM,
.membase = (char __iomem *)io_p2v(NETX_PA_UART2),
.mapbase = NETX_PA_UART2,
.irq = NETX_IRQ_UART2,
.uartclk = 100000000,
.fifosize = 16,
.flags = UPF_BOOT_AUTOCONF,
.ops = &netx_pops,
.line = 2,
},
}
};
static void netx_console_putchar(struct uart_port *port, int ch)
{
while (readl(port->membase + UART_FR) & FR_BUSY);
writel(ch, port->membase + UART_DR);
}
static void
netx_console_write(struct console *co, const char *s, unsigned int count)
{
struct uart_port *port = &netx_ports[co->index].port;
unsigned char cr_save;
cr_save = readl(port->membase + UART_CR);
writel(cr_save | CR_UART_EN, port->membase + UART_CR);
uart_console_write(port, s, count, netx_console_putchar);
while (readl(port->membase + UART_FR) & FR_BUSY);
writel(cr_save, port->membase + UART_CR);
}
static void __init
netx_console_get_options(struct uart_port *port, int *baud,
int *parity, int *bits, int *flow)
{
unsigned char line_cr;
*baud = (readl(port->membase + UART_BAUDDIV_MSB) << 8) |
readl(port->membase + UART_BAUDDIV_LSB);
*baud *= 1000;
*baud /= 4096;
*baud *= 1000;
*baud /= 256;
*baud *= 100;
line_cr = readl(port->membase + UART_LINE_CR);
*parity = 'n';
if (line_cr & LINE_CR_PEN) {
if (line_cr & LINE_CR_EPS)
*parity = 'e';
else
*parity = 'o';
}
switch (line_cr & LINE_CR_BITS_MASK) {
case LINE_CR_8BIT:
*bits = 8;
break;
case LINE_CR_7BIT:
*bits = 7;
break;
case LINE_CR_6BIT:
*bits = 6;
break;
case LINE_CR_5BIT:
*bits = 5;
break;
}
if (readl(port->membase + UART_RTS_CR) & RTS_CR_AUTO)
*flow = 'r';
}
static int __init
netx_console_setup(struct console *co, char *options)
{
struct netx_port *sport;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
/*
* Check whether an invalid uart number has been specified, and
* if so, search for the first available port that does have
* console support.
*/
if (co->index == -1 || co->index >= ARRAY_SIZE(netx_ports))
co->index = 0;
sport = &netx_ports[co->index];
if (options) {
uart_parse_options(options, &baud, &parity, &bits, &flow);
} else {
/* if the UART is enabled, assume it has been correctly setup
* by the bootloader and get the options
*/
if (readl(sport->port.membase + UART_CR) & CR_UART_EN) {
netx_console_get_options(&sport->port, &baud,
&parity, &bits, &flow);
}
}
return uart_set_options(&sport->port, co, baud, parity, bits, flow);
}
static struct uart_driver netx_reg;
static struct console netx_console = {
.name = "ttyNX",
.write = netx_console_write,
.device = uart_console_device,
.setup = netx_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &netx_reg,
};
static int __init netx_console_init(void)
{
register_console(&netx_console);
return 0;
}
console_initcall(netx_console_init);
#define NETX_CONSOLE &netx_console
#else
#define NETX_CONSOLE NULL
#endif
static struct uart_driver netx_reg = {
.owner = THIS_MODULE,
.driver_name = DRIVER_NAME,
.dev_name = "ttyNX",
.major = SERIAL_NX_MAJOR,
.minor = MINOR_START,
.nr = ARRAY_SIZE(netx_ports),
.cons = NETX_CONSOLE,
};
static int serial_netx_suspend(struct platform_device *pdev, pm_message_t state)
{
struct netx_port *sport = platform_get_drvdata(pdev);
if (sport)
uart_suspend_port(&netx_reg, &sport->port);
return 0;
}
static int serial_netx_resume(struct platform_device *pdev)
{
struct netx_port *sport = platform_get_drvdata(pdev);
if (sport)
uart_resume_port(&netx_reg, &sport->port);
return 0;
}
static int serial_netx_probe(struct platform_device *pdev)
{
struct uart_port *port = &netx_ports[pdev->id].port;
dev_info(&pdev->dev, "initialising\n");
port->dev = &pdev->dev;
writel(1, port->membase + UART_RXFIFO_IRQLEVEL);
uart_add_one_port(&netx_reg, &netx_ports[pdev->id].port);
platform_set_drvdata(pdev, &netx_ports[pdev->id]);
return 0;
}
static int serial_netx_remove(struct platform_device *pdev)
{
struct netx_port *sport = platform_get_drvdata(pdev);
platform_set_drvdata(pdev, NULL);
if (sport)
uart_remove_one_port(&netx_reg, &sport->port);
return 0;
}
static struct platform_driver serial_netx_driver = {
.probe = serial_netx_probe,
.remove = serial_netx_remove,
.suspend = serial_netx_suspend,
.resume = serial_netx_resume,
.driver = {
.name = DRIVER_NAME,
},
};
static int __init netx_serial_init(void)
{
int ret;
printk(KERN_INFO "Serial: NetX driver\n");
ret = uart_register_driver(&netx_reg);
if (ret)
return ret;
ret = platform_driver_register(&serial_netx_driver);
if (ret != 0)
uart_unregister_driver(&netx_reg);
return 0;
}
static void __exit netx_serial_exit(void)
{
platform_driver_unregister(&serial_netx_driver);
uart_unregister_driver(&netx_reg);
}
module_init(netx_serial_init);
module_exit(netx_serial_exit);
MODULE_AUTHOR("Sascha Hauer");
MODULE_DESCRIPTION("NetX serial port driver");
MODULE_LICENSE("GPL");