#include <linux/module.h>
#include <linux/device.h>
#include <linux/console.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/clps711x.h>
#include "serial_mctrl_gpio.h"
#define UART_CLPS711X_DEVNAME "ttyCL"
#define UART_CLPS711X_NR 2
#define UART_CLPS711X_MAJOR 204
#define UART_CLPS711X_MINOR 40
#define UARTDR_OFFSET (0x00)
#define UBRLCR_OFFSET (0x40)
#define UARTDR_FRMERR (1 << 8)
#define UARTDR_PARERR (1 << 9)
#define UARTDR_OVERR (1 << 10)
#define UBRLCR_BAUD_MASK ((1 << 12) - 1)
#define UBRLCR_BREAK (1 << 12)
#define UBRLCR_PRTEN (1 << 13)
#define UBRLCR_EVENPRT (1 << 14)
#define UBRLCR_XSTOP (1 << 15)
#define UBRLCR_FIFOEN (1 << 16)
#define UBRLCR_WRDLEN5 (0 << 17)
#define UBRLCR_WRDLEN6 (1 << 17)
#define UBRLCR_WRDLEN7 (2 << 17)
#define UBRLCR_WRDLEN8 (3 << 17)
#define UBRLCR_WRDLEN_MASK (3 << 17)
struct clps711x_port {
struct uart_port port;
unsigned int tx_enabled;
int rx_irq;
struct regmap *syscon;
struct mctrl_gpios *gpios;
};
static struct uart_driver clps711x_uart = {
.owner = THIS_MODULE,
.driver_name = UART_CLPS711X_DEVNAME,
.dev_name = UART_CLPS711X_DEVNAME,
.major = UART_CLPS711X_MAJOR,
.minor = UART_CLPS711X_MINOR,
.nr = UART_CLPS711X_NR,
};
static void uart_clps711x_stop_tx(struct uart_port *port)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
if (s->tx_enabled) {
disable_irq(port->irq);
s->tx_enabled = 0;
}
}
static void uart_clps711x_start_tx(struct uart_port *port)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
if (!s->tx_enabled) {
s->tx_enabled = 1;
enable_irq(port->irq);
}
}
static irqreturn_t uart_clps711x_int_rx(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct clps711x_port *s = dev_get_drvdata(port->dev);
unsigned int status;
u16 ch;
u8 flg;
for (;;) {
u32 sysflg = 0;
regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
if (sysflg & SYSFLG_URXFE)
break;
ch = readw(port->membase + UARTDR_OFFSET);
status = ch & (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR);
ch &= 0xff;
port->icount.rx++;
flg = TTY_NORMAL;
if (unlikely(status)) {
if (status & UARTDR_PARERR)
port->icount.parity++;
else if (status & UARTDR_FRMERR)
port->icount.frame++;
else if (status & UARTDR_OVERR)
port->icount.overrun++;
status &= port->read_status_mask;
if (status & UARTDR_PARERR)
flg = TTY_PARITY;
else if (status & UARTDR_FRMERR)
flg = TTY_FRAME;
else if (status & UARTDR_OVERR)
flg = TTY_OVERRUN;
}
if (uart_handle_sysrq_char(port, ch))
continue;
if (status & port->ignore_status_mask)
continue;
uart_insert_char(port, status, UARTDR_OVERR, ch, flg);
}
tty_flip_buffer_push(&port->state->port);
return IRQ_HANDLED;
}
static irqreturn_t uart_clps711x_int_tx(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct clps711x_port *s = dev_get_drvdata(port->dev);
struct tty_port *tport = &port->state->port;
unsigned char c;
if (port->x_char) {
writew(port->x_char, port->membase + UARTDR_OFFSET);
port->icount.tx++;
port->x_char = 0;
return IRQ_HANDLED;
}
if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) {
if (s->tx_enabled) {
disable_irq_nosync(port->irq);
s->tx_enabled = 0;
}
return IRQ_HANDLED;
}
while (uart_fifo_get(port, &c)) {
u32 sysflg = 0;
writew(c, port->membase + UARTDR_OFFSET);
regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
if (sysflg & SYSFLG_UTXFF)
break;
}
if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
uart_write_wakeup(port);
return IRQ_HANDLED;
}
static unsigned int uart_clps711x_tx_empty(struct uart_port *port)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
u32 sysflg = 0;
regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
return (sysflg & SYSFLG_UBUSY) ? 0 : TIOCSER_TEMT;
}
static unsigned int uart_clps711x_get_mctrl(struct uart_port *port)
{
unsigned int result = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
struct clps711x_port *s = dev_get_drvdata(port->dev);
return mctrl_gpio_get(s->gpios, &result);
}
static void uart_clps711x_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
mctrl_gpio_set(s->gpios, mctrl);
}
static void uart_clps711x_break_ctl(struct uart_port *port, int break_state)
{
unsigned int ubrlcr;
ubrlcr = readl(port->membase + UBRLCR_OFFSET);
if (break_state)
ubrlcr |= UBRLCR_BREAK;
else
ubrlcr &= ~UBRLCR_BREAK;
writel(ubrlcr, port->membase + UBRLCR_OFFSET);
}
static void uart_clps711x_set_ldisc(struct uart_port *port,
struct ktermios *termios)
{
if (!port->line) {
struct clps711x_port *s = dev_get_drvdata(port->dev);
regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON1_SIREN,
(termios->c_line == N_IRDA) ? SYSCON1_SIREN : 0);
}
}
static int uart_clps711x_startup(struct uart_port *port)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
writel(readl(port->membase + UBRLCR_OFFSET) & ~UBRLCR_BREAK,
port->membase + UBRLCR_OFFSET);
return regmap_update_bits(s->syscon, SYSCON_OFFSET,
SYSCON_UARTEN, SYSCON_UARTEN);
}
static void uart_clps711x_shutdown(struct uart_port *port)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON_UARTEN, 0);
}
static void uart_clps711x_set_termios(struct uart_port *port,
struct ktermios *termios,
const struct ktermios *old)
{
u32 ubrlcr;
unsigned int baud, quot;
termios->c_cflag &= ~CMSPAR;
termios->c_iflag &= ~(BRKINT | IGNBRK);
baud = uart_get_baud_rate(port, termios, old, port->uartclk / 4096,
port->uartclk / 16);
quot = uart_get_divisor(port, baud);
switch (termios->c_cflag & CSIZE) {
case CS5:
ubrlcr = UBRLCR_WRDLEN5;
break;
case CS6:
ubrlcr = UBRLCR_WRDLEN6;
break;
case CS7:
ubrlcr = UBRLCR_WRDLEN7;
break;
case CS8:
default:
ubrlcr = UBRLCR_WRDLEN8;
break;
}
if (termios->c_cflag & CSTOPB)
ubrlcr |= UBRLCR_XSTOP;
if (termios->c_cflag & PARENB) {
ubrlcr |= UBRLCR_PRTEN;
if (!(termios->c_cflag & PARODD))
ubrlcr |= UBRLCR_EVENPRT;
}
ubrlcr |= UBRLCR_FIFOEN;
port->read_status_mask = UARTDR_OVERR;
if (termios->c_iflag & INPCK)
port->read_status_mask |= UARTDR_PARERR | UARTDR_FRMERR;
port->ignore_status_mask = 0;
if (!(termios->c_cflag & CREAD))
port->ignore_status_mask |= UARTDR_OVERR | UARTDR_PARERR |
UARTDR_FRMERR;
uart_update_timeout(port, termios->c_cflag, baud);
writel(ubrlcr | (quot - 1), port->membase + UBRLCR_OFFSET);
}
static const char *uart_clps711x_type(struct uart_port *port)
{
return (port->type == PORT_CLPS711X) ? "CLPS711X" : NULL;
}
static void uart_clps711x_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE)
port->type = PORT_CLPS711X;
}
static void uart_clps711x_nop_void(struct uart_port *port)
{
}
static int uart_clps711x_nop_int(struct uart_port *port)
{
return 0;
}
static const struct uart_ops uart_clps711x_ops = {
.tx_empty = uart_clps711x_tx_empty,
.set_mctrl = uart_clps711x_set_mctrl,
.get_mctrl = uart_clps711x_get_mctrl,
.stop_tx = uart_clps711x_stop_tx,
.start_tx = uart_clps711x_start_tx,
.stop_rx = uart_clps711x_nop_void,
.break_ctl = uart_clps711x_break_ctl,
.set_ldisc = uart_clps711x_set_ldisc,
.startup = uart_clps711x_startup,
.shutdown = uart_clps711x_shutdown,
.set_termios = uart_clps711x_set_termios,
.type = uart_clps711x_type,
.config_port = uart_clps711x_config_port,
.release_port = uart_clps711x_nop_void,
.request_port = uart_clps711x_nop_int,
};
#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
static void uart_clps711x_console_putchar(struct uart_port *port, unsigned char ch)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
u32 sysflg = 0;
do {
regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
} while (sysflg & SYSFLG_UTXFF);
writew(ch, port->membase + UARTDR_OFFSET);
}
static void uart_clps711x_console_write(struct console *co, const char *c,
unsigned n)
{
struct uart_port *port = clps711x_uart.state[co->index].uart_port;
struct clps711x_port *s = dev_get_drvdata(port->dev);
u32 sysflg = 0;
uart_console_write(port, c, n, uart_clps711x_console_putchar);
do {
regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
} while (sysflg & SYSFLG_UBUSY);
}
static int uart_clps711x_console_setup(struct console *co, char *options)
{
int baud = 38400, bits = 8, parity = 'n', flow = 'n';
int ret, index = co->index;
struct clps711x_port *s;
struct uart_port *port;
unsigned int quot;
u32 ubrlcr;
if (index < 0 || index >= UART_CLPS711X_NR)
return -EINVAL;
port = clps711x_uart.state[index].uart_port;
if (!port)
return -ENODEV;
s = dev_get_drvdata(port->dev);
if (!options) {
u32 syscon = 0;
regmap_read(s->syscon, SYSCON_OFFSET, &syscon);
if (syscon & SYSCON_UARTEN) {
ubrlcr = readl(port->membase + UBRLCR_OFFSET);
if (ubrlcr & UBRLCR_PRTEN) {
if (ubrlcr & UBRLCR_EVENPRT)
parity = 'e';
else
parity = 'o';
}
if ((ubrlcr & UBRLCR_WRDLEN_MASK) == UBRLCR_WRDLEN7)
bits = 7;
quot = ubrlcr & UBRLCR_BAUD_MASK;
baud = port->uartclk / (16 * (quot + 1));
}
} else
uart_parse_options(options, &baud, &parity, &bits, &flow);
ret = uart_set_options(port, co, baud, parity, bits, flow);
if (ret)
return ret;
return regmap_update_bits(s->syscon, SYSCON_OFFSET,
SYSCON_UARTEN, SYSCON_UARTEN);
}
static struct console clps711x_console = {
.name = UART_CLPS711X_DEVNAME,
.device = uart_console_device,
.write = uart_clps711x_console_write,
.setup = uart_clps711x_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
#endif
static int uart_clps711x_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct clps711x_port *s;
struct resource *res;
struct clk *uart_clk;
int irq, ret;
s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
if (!s)
return -ENOMEM;
uart_clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(uart_clk))
return PTR_ERR(uart_clk);
s->port.membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(s->port.membase))
return PTR_ERR(s->port.membase);
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
s->port.irq = irq;
s->rx_irq = platform_get_irq(pdev, 1);
if (s->rx_irq < 0)
return s->rx_irq;
s->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
if (IS_ERR(s->syscon))
return PTR_ERR(s->syscon);
s->port.line = of_alias_get_id(np, "serial");
s->port.dev = &pdev->dev;
s->port.iotype = UPIO_MEM32;
s->port.mapbase = res->start;
s->port.type = PORT_CLPS711X;
s->port.fifosize = 16;
s->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_CLPS711X_CONSOLE);
s->port.flags = UPF_SKIP_TEST | UPF_FIXED_TYPE;
s->port.uartclk = clk_get_rate(uart_clk);
s->port.ops = &uart_clps711x_ops;
platform_set_drvdata(pdev, s);
s->gpios = mctrl_gpio_init_noauto(&pdev->dev, 0);
if (IS_ERR(s->gpios))
return PTR_ERR(s->gpios);
ret = uart_add_one_port(&clps711x_uart, &s->port);
if (ret)
return ret;
if (!uart_console(&s->port))
regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON_UARTEN, 0);
s->tx_enabled = 1;
ret = devm_request_irq(&pdev->dev, s->port.irq, uart_clps711x_int_tx, 0,
dev_name(&pdev->dev), &s->port);
if (ret) {
uart_remove_one_port(&clps711x_uart, &s->port);
return ret;
}
ret = devm_request_irq(&pdev->dev, s->rx_irq, uart_clps711x_int_rx, 0,
dev_name(&pdev->dev), &s->port);
if (ret)
uart_remove_one_port(&clps711x_uart, &s->port);
return ret;
}
static void uart_clps711x_remove(struct platform_device *pdev)
{
struct clps711x_port *s = platform_get_drvdata(pdev);
uart_remove_one_port(&clps711x_uart, &s->port);
}
static const struct of_device_id __maybe_unused clps711x_uart_dt_ids[] = {
{ .compatible = "cirrus,ep7209-uart", },
{ }
};
MODULE_DEVICE_TABLE(of, clps711x_uart_dt_ids);
static struct platform_driver clps711x_uart_platform = {
.driver = {
.name = "clps711x-uart",
.of_match_table = of_match_ptr(clps711x_uart_dt_ids),
},
.probe = uart_clps711x_probe,
.remove = uart_clps711x_remove,
};
static int __init uart_clps711x_init(void)
{
int ret;
#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
clps711x_uart.cons = &clps711x_console;
clps711x_console.data = &clps711x_uart;
#endif
ret = uart_register_driver(&clps711x_uart);
if (ret)
return ret;
return platform_driver_register(&clps711x_uart_platform);
}
module_init(uart_clps711x_init);
static void __exit uart_clps711x_exit(void)
{
platform_driver_unregister(&clps711x_uart_platform);
uart_unregister_driver(&clps711x_uart);
}
module_exit(uart_clps711x_exit);
MODULE_AUTHOR("Deep Blue Solutions Ltd");
MODULE_DESCRIPTION("CLPS711X serial driver");
MODULE_LICENSE("GPL");
