--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Socionext Inc.
+ */
+
+#if defined(CONFIG_SERIAL_MILBEAUT_USIO_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define USIO_NAME "mlb-usio-uart"
+#define USIO_UART_DEV_NAME "ttyUSI"
+
+static struct uart_port mlb_usio_ports[CONFIG_SERIAL_MILBEAUT_USIO_PORTS];
+
+#define RX 0
+#define TX 1
+static int mlb_usio_irq[CONFIG_SERIAL_MILBEAUT_USIO_PORTS][2];
+
+#define MLB_USIO_REG_SMR 0
+#define MLB_USIO_REG_SCR 1
+#define MLB_USIO_REG_ESCR 2
+#define MLB_USIO_REG_SSR 3
+#define MLB_USIO_REG_DR 4
+#define MLB_USIO_REG_BGR 6
+#define MLB_USIO_REG_FCR 12
+#define MLB_USIO_REG_FBYTE 14
+
+#define MLB_USIO_SMR_SOE BIT(0)
+#define MLB_USIO_SMR_SBL BIT(3)
+#define MLB_USIO_SCR_TXE BIT(0)
+#define MLB_USIO_SCR_RXE BIT(1)
+#define MLB_USIO_SCR_TBIE BIT(2)
+#define MLB_USIO_SCR_TIE BIT(3)
+#define MLB_USIO_SCR_RIE BIT(4)
+#define MLB_USIO_SCR_UPCL BIT(7)
+#define MLB_USIO_ESCR_L_8BIT 0
+#define MLB_USIO_ESCR_L_5BIT 1
+#define MLB_USIO_ESCR_L_6BIT 2
+#define MLB_USIO_ESCR_L_7BIT 3
+#define MLB_USIO_ESCR_P BIT(3)
+#define MLB_USIO_ESCR_PEN BIT(4)
+#define MLB_USIO_ESCR_FLWEN BIT(7)
+#define MLB_USIO_SSR_TBI BIT(0)
+#define MLB_USIO_SSR_TDRE BIT(1)
+#define MLB_USIO_SSR_RDRF BIT(2)
+#define MLB_USIO_SSR_ORE BIT(3)
+#define MLB_USIO_SSR_FRE BIT(4)
+#define MLB_USIO_SSR_PE BIT(5)
+#define MLB_USIO_SSR_REC BIT(7)
+#define MLB_USIO_SSR_BRK BIT(8)
+#define MLB_USIO_FCR_FE1 BIT(0)
+#define MLB_USIO_FCR_FE2 BIT(1)
+#define MLB_USIO_FCR_FCL1 BIT(2)
+#define MLB_USIO_FCR_FCL2 BIT(3)
+#define MLB_USIO_FCR_FSET BIT(4)
+#define MLB_USIO_FCR_FTIE BIT(9)
+#define MLB_USIO_FCR_FDRQ BIT(10)
+#define MLB_USIO_FCR_FRIIE BIT(11)
+
+static void mlb_usio_stop_tx(struct uart_port *port)
+{
+ writew(readw(port->membase + MLB_USIO_REG_FCR) & ~MLB_USIO_FCR_FTIE,
+ port->membase + MLB_USIO_REG_FCR);
+ writeb(readb(port->membase + MLB_USIO_REG_SCR) & ~MLB_USIO_SCR_TBIE,
+ port->membase + MLB_USIO_REG_SCR);
+}
+
+static void mlb_usio_tx_chars(struct uart_port *port)
+{
+ struct circ_buf *xmit = &port->state->xmit;
+ int count;
+
+ writew(readw(port->membase + MLB_USIO_REG_FCR) & ~MLB_USIO_FCR_FTIE,
+ port->membase + MLB_USIO_REG_FCR);
+ writeb(readb(port->membase + MLB_USIO_REG_SCR) &
+ ~(MLB_USIO_SCR_TIE | MLB_USIO_SCR_TBIE),
+ port->membase + MLB_USIO_REG_SCR);
+
+ if (port->x_char) {
+ writew(port->x_char, port->membase + MLB_USIO_REG_DR);
+ port->icount.tx++;
+ port->x_char = 0;
+ return;
+ }
+ if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+ mlb_usio_stop_tx(port);
+ return;
+ }
+
+ count = port->fifosize -
+ (readw(port->membase + MLB_USIO_REG_FBYTE) & 0xff);
+
+ do {
+ writew(xmit->buf[xmit->tail], port->membase + MLB_USIO_REG_DR);
+
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ port->icount.tx++;
+ if (uart_circ_empty(xmit))
+ break;
+
+ } while (--count > 0);
+
+ writew(readw(port->membase + MLB_USIO_REG_FCR) & ~MLB_USIO_FCR_FDRQ,
+ port->membase + MLB_USIO_REG_FCR);
+
+ writeb(readb(port->membase + MLB_USIO_REG_SCR) | MLB_USIO_SCR_TBIE,
+ port->membase + MLB_USIO_REG_SCR);
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+
+ if (uart_circ_empty(xmit))
+ mlb_usio_stop_tx(port);
+}
+
+static void mlb_usio_start_tx(struct uart_port *port)
+{
+ u16 fcr = readw(port->membase + MLB_USIO_REG_FCR);
+
+ writew(fcr | MLB_USIO_FCR_FTIE, port->membase + MLB_USIO_REG_FCR);
+ if (!(fcr & MLB_USIO_FCR_FDRQ))
+ return;
+
+ writeb(readb(port->membase + MLB_USIO_REG_SCR) | MLB_USIO_SCR_TBIE,
+ port->membase + MLB_USIO_REG_SCR);
+
+ if (readb(port->membase + MLB_USIO_REG_SSR) & MLB_USIO_SSR_TBI)
+ mlb_usio_tx_chars(port);
+}
+
+static void mlb_usio_stop_rx(struct uart_port *port)
+{
+ writeb(readb(port->membase + MLB_USIO_REG_SCR) & ~MLB_USIO_SCR_RIE,
+ port->membase + MLB_USIO_REG_SCR);
+}
+
+static void mlb_usio_enable_ms(struct uart_port *port)
+{
+ writeb(readb(port->membase + MLB_USIO_REG_SCR) |
+ MLB_USIO_SCR_RIE | MLB_USIO_SCR_RXE,
+ port->membase + MLB_USIO_REG_SCR);
+}
+
+static void mlb_usio_rx_chars(struct uart_port *port)
+{
+ struct tty_port *ttyport = &port->state->port;
+ unsigned long flag = 0;
+ char ch = 0;
+ u8 status;
+ int max_count = 2;
+
+ while (max_count--) {
+ status = readb(port->membase + MLB_USIO_REG_SSR);
+
+ if (!(status & MLB_USIO_SSR_RDRF))
+ break;
+
+ if (!(status & (MLB_USIO_SSR_ORE | MLB_USIO_SSR_FRE |
+ MLB_USIO_SSR_PE))) {
+ ch = readw(port->membase + MLB_USIO_REG_DR);
+ flag = TTY_NORMAL;
+ port->icount.rx++;
+ if (uart_handle_sysrq_char(port, ch))
+ continue;
+ uart_insert_char(port, status, MLB_USIO_SSR_ORE,
+ ch, flag);
+ continue;
+ }
+ if (status & MLB_USIO_SSR_PE)
+ port->icount.parity++;
+ if (status & MLB_USIO_SSR_ORE)
+ port->icount.overrun++;
+ status &= port->read_status_mask;
+ if (status & MLB_USIO_SSR_BRK) {
+ flag = TTY_BREAK;
+ ch = 0;
+ } else
+ if (status & MLB_USIO_SSR_PE) {
+ flag = TTY_PARITY;
+ ch = 0;
+ } else
+ if (status & MLB_USIO_SSR_FRE) {
+ flag = TTY_FRAME;
+ ch = 0;
+ }
+ if (flag)
+ uart_insert_char(port, status, MLB_USIO_SSR_ORE,
+ ch, flag);
+
+ writeb(readb(port->membase + MLB_USIO_REG_SSR) |
+ MLB_USIO_SSR_REC,
+ port->membase + MLB_USIO_REG_SSR);
+
+ max_count = readw(port->membase + MLB_USIO_REG_FBYTE) >> 8;
+ writew(readw(port->membase + MLB_USIO_REG_FCR) |
+ MLB_USIO_FCR_FE2 | MLB_USIO_FCR_FRIIE,
+ port->membase + MLB_USIO_REG_FCR);
+ }
+
+ tty_flip_buffer_push(ttyport);
+}
+
+static irqreturn_t mlb_usio_rx_irq(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+
+ spin_lock(&port->lock);
+ mlb_usio_rx_chars(port);
+ spin_unlock(&port->lock);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t mlb_usio_tx_irq(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+
+ spin_lock(&port->lock);
+ if (readb(port->membase + MLB_USIO_REG_SSR) & MLB_USIO_SSR_TBI)
+ mlb_usio_tx_chars(port);
+ spin_unlock(&port->lock);
+
+ return IRQ_HANDLED;
+}
+
+static unsigned int mlb_usio_tx_empty(struct uart_port *port)
+{
+ return (readb(port->membase + MLB_USIO_REG_SSR) & MLB_USIO_SSR_TBI) ?
+ TIOCSER_TEMT : 0;
+}
+
+static void mlb_usio_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static unsigned int mlb_usio_get_mctrl(struct uart_port *port)
+{
+ return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+
+}
+
+static void mlb_usio_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static int mlb_usio_startup(struct uart_port *port)
+{
+ const char *portname = to_platform_device(port->dev)->name;
+ unsigned long flags;
+ int ret, index = port->line;
+ unsigned char escr;
+
+ ret = request_irq(mlb_usio_irq[index][RX], mlb_usio_rx_irq,
+ 0, portname, port);
+ if (ret)
+ return ret;
+ ret = request_irq(mlb_usio_irq[index][TX], mlb_usio_tx_irq,
+ 0, portname, port);
+ if (ret) {
+ free_irq(mlb_usio_irq[index][RX], port);
+ return ret;
+ }
+
+ escr = readb(port->membase + MLB_USIO_REG_ESCR);
+ if (of_property_read_bool(port->dev->of_node, "auto-flow-control"))
+ escr |= MLB_USIO_ESCR_FLWEN;
+ spin_lock_irqsave(&port->lock, flags);
+ writeb(0, port->membase + MLB_USIO_REG_SCR);
+ writeb(escr, port->membase + MLB_USIO_REG_ESCR);
+ writeb(MLB_USIO_SCR_UPCL, port->membase + MLB_USIO_REG_SCR);
+ writeb(MLB_USIO_SSR_REC, port->membase + MLB_USIO_REG_SSR);
+ writew(0, port->membase + MLB_USIO_REG_FCR);
+ writew(MLB_USIO_FCR_FCL1 | MLB_USIO_FCR_FCL2,
+ port->membase + MLB_USIO_REG_FCR);
+ writew(MLB_USIO_FCR_FE1 | MLB_USIO_FCR_FE2 | MLB_USIO_FCR_FRIIE,
+ port->membase + MLB_USIO_REG_FCR);
+ writew(0, port->membase + MLB_USIO_REG_FBYTE);
+ writew(BIT(12), port->membase + MLB_USIO_REG_FBYTE);
+
+ writeb(MLB_USIO_SCR_TXE | MLB_USIO_SCR_RIE | MLB_USIO_SCR_TBIE |
+ MLB_USIO_SCR_RXE, port->membase + MLB_USIO_REG_SCR);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return 0;
+}
+
+static void mlb_usio_shutdown(struct uart_port *port)
+{
+ int index = port->line;
+
+ free_irq(mlb_usio_irq[index][RX], port);
+ free_irq(mlb_usio_irq[index][TX], port);
+}
+
+static void mlb_usio_set_termios(struct uart_port *port,
+ struct ktermios *termios, struct ktermios *old)
+{
+ unsigned int escr, smr = MLB_USIO_SMR_SOE;
+ unsigned long flags, baud, quot;
+
+ switch (termios->c_cflag & CSIZE) {
+ case CS5:
+ escr = MLB_USIO_ESCR_L_5BIT;
+ break;
+ case CS6:
+ escr = MLB_USIO_ESCR_L_6BIT;
+ break;
+ case CS7:
+ escr = MLB_USIO_ESCR_L_7BIT;
+ break;
+ case CS8:
+ default:
+ escr = MLB_USIO_ESCR_L_8BIT;
+ break;
+ }
+
+ if (termios->c_cflag & CSTOPB)
+ smr |= MLB_USIO_SMR_SBL;
+
+ if (termios->c_cflag & PARENB) {
+ escr |= MLB_USIO_ESCR_PEN;
+ if (termios->c_cflag & PARODD)
+ escr |= MLB_USIO_ESCR_P;
+ }
+ /* Set hard flow control */
+ if (of_property_read_bool(port->dev->of_node, "auto-flow-control") ||
+ (termios->c_cflag & CRTSCTS))
+ escr |= MLB_USIO_ESCR_FLWEN;
+
+ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk);
+ if (baud > 1)
+ quot = port->uartclk / baud - 1;
+ else
+ quot = 0;
+
+ spin_lock_irqsave(&port->lock, flags);
+ uart_update_timeout(port, termios->c_cflag, baud);
+ port->read_status_mask = MLB_USIO_SSR_ORE | MLB_USIO_SSR_RDRF |
+ MLB_USIO_SSR_TDRE;
+ if (termios->c_iflag & INPCK)
+ port->read_status_mask |= MLB_USIO_SSR_FRE | MLB_USIO_SSR_PE;
+
+ port->ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= MLB_USIO_SSR_FRE | MLB_USIO_SSR_PE;
+ if ((termios->c_iflag & IGNBRK) && (termios->c_iflag & IGNPAR))
+ port->ignore_status_mask |= MLB_USIO_SSR_ORE;
+ if ((termios->c_cflag & CREAD) == 0)
+ port->ignore_status_mask |= MLB_USIO_SSR_RDRF;
+
+ writeb(0, port->membase + MLB_USIO_REG_SCR);
+ writeb(MLB_USIO_SCR_UPCL, port->membase + MLB_USIO_REG_SCR);
+ writeb(MLB_USIO_SSR_REC, port->membase + MLB_USIO_REG_SSR);
+ writew(0, port->membase + MLB_USIO_REG_FCR);
+ writeb(smr, port->membase + MLB_USIO_REG_SMR);
+ writeb(escr, port->membase + MLB_USIO_REG_ESCR);
+ writew(quot, port->membase + MLB_USIO_REG_BGR);
+ writew(0, port->membase + MLB_USIO_REG_FCR);
+ writew(MLB_USIO_FCR_FCL1 | MLB_USIO_FCR_FCL2 | MLB_USIO_FCR_FE1 |
+ MLB_USIO_FCR_FE2 | MLB_USIO_FCR_FRIIE,
+ port->membase + MLB_USIO_REG_FCR);
+ writew(0, port->membase + MLB_USIO_REG_FBYTE);
+ writew(BIT(12), port->membase + MLB_USIO_REG_FBYTE);
+ writeb(MLB_USIO_SCR_RIE | MLB_USIO_SCR_RXE | MLB_USIO_SCR_TBIE |
+ MLB_USIO_SCR_TXE, port->membase + MLB_USIO_REG_SCR);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *mlb_usio_type(struct uart_port *port)
+{
+ return ((port->type == PORT_MLB_USIO) ? USIO_NAME : NULL);
+}
+
+static void mlb_usio_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE)
+ port->type = PORT_MLB_USIO;
+}
+
+static const struct uart_ops mlb_usio_ops = {
+ .tx_empty = mlb_usio_tx_empty,
+ .set_mctrl = mlb_usio_set_mctrl,
+ .get_mctrl = mlb_usio_get_mctrl,
+ .stop_tx = mlb_usio_stop_tx,
+ .start_tx = mlb_usio_start_tx,
+ .stop_rx = mlb_usio_stop_rx,
+ .enable_ms = mlb_usio_enable_ms,
+ .break_ctl = mlb_usio_break_ctl,
+ .startup = mlb_usio_startup,
+ .shutdown = mlb_usio_shutdown,
+ .set_termios = mlb_usio_set_termios,
+ .type = mlb_usio_type,
+ .config_port = mlb_usio_config_port,
+};
+
+#ifdef CONFIG_SERIAL_MILBEAUT_USIO_CONSOLE
+
+static void mlb_usio_console_putchar(struct uart_port *port, int c)
+{
+ while (!(readb(port->membase + MLB_USIO_REG_SSR) & MLB_USIO_SSR_TDRE))
+ cpu_relax();
+
+ writew(c, port->membase + MLB_USIO_REG_DR);
+}
+
+static void mlb_usio_console_write(struct console *co, const char *s,
+ unsigned int count)
+{
+ struct uart_port *port = &mlb_usio_ports[co->index];
+
+ uart_console_write(port, s, count, mlb_usio_console_putchar);
+}
+
+static int __init mlb_usio_console_setup(struct console *co, char *options)
+{
+ struct uart_port *port;
+ int baud = 115200;
+ int parity = 'n';
+ int flow = 'n';
+ int bits = 8;
+
+ if (co->index >= CONFIG_SERIAL_MILBEAUT_USIO_PORTS)
+ return -ENODEV;
+
+ port = &mlb_usio_ports[co->index];
+ if (!port->membase)
+ return -ENODEV;
+
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+ if (of_property_read_bool(port->dev->of_node, "auto-flow-control"))
+ flow = 'r';
+
+ return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+
+static struct uart_driver mlb_usio_uart_driver;
+static struct console mlb_usio_console = {
+ .name = USIO_UART_DEV_NAME,
+ .write = mlb_usio_console_write,
+ .device = uart_console_device,
+ .setup = mlb_usio_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &mlb_usio_uart_driver,
+};
+
+static int __init mlb_usio_console_init(void)
+{
+ register_console(&mlb_usio_console);
+ return 0;
+}
+console_initcall(mlb_usio_console_init);
+
+
+static void mlb_usio_early_console_write(struct console *co, const char *s,
+ u_int count)
+{
+ struct earlycon_device *dev = co->data;
+
+ uart_console_write(&dev->port, s, count, mlb_usio_console_putchar);
+}
+
+static int __init mlb_usio_early_console_setup(struct earlycon_device *device,
+ const char *opt)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+ device->con->write = mlb_usio_early_console_write;
+ return 0;
+}
+
+OF_EARLYCON_DECLARE(mlb_usio, "socionext,milbeaut-usio-uart",
+ mlb_usio_early_console_setup);
+
+#define USIO_CONSOLE (&mlb_usio_console)
+#else
+#define USIO_CONSOLE NULL
+#endif
+
+static struct uart_driver mlb_usio_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = USIO_NAME,
+ .dev_name = USIO_UART_DEV_NAME,
+ .cons = USIO_CONSOLE,
+ .nr = CONFIG_SERIAL_MILBEAUT_USIO_PORTS,
+};
+
+static int mlb_usio_probe(struct platform_device *pdev)
+{
+ struct clk *clk = devm_clk_get(&pdev->dev, 0);
+ struct uart_port *port;
+ struct resource *res;
+ int index = 0;
+ int ret;
+
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "Missing clock\n");
+ return PTR_ERR(clk);
+ }
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Clock enable failed: %d\n", ret);
+ return ret;
+ }
+ of_property_read_u32(pdev->dev.of_node, "index", &index);
+ port = &mlb_usio_ports[index];
+
+ port->private_data = (void *)clk;
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (res == NULL) {
+ dev_err(&pdev->dev, "Missing regs\n");
+ ret = -ENODEV;
+ goto failed;
+ }
+ port->mapbase = res->start;
+ port->membase = ioremap(res->start, (res->end - res->start + 1));
+ port->membase = devm_ioremap(&pdev->dev, res->start,
+ resource_size(res));
+
+ ret = platform_get_irq_byname(pdev, "rx");
+ mlb_usio_irq[index][RX] = ret;
+
+ ret = platform_get_irq_byname(pdev, "tx");
+ mlb_usio_irq[index][TX] = ret;
+
+ port->irq = mlb_usio_irq[index][RX];
+ port->uartclk = clk_get_rate(clk);
+ port->fifosize = 128;
+ port->iotype = UPIO_MEM32;
+ port->flags = UPF_BOOT_AUTOCONF | UPF_SPD_VHI;
+ port->line = index;
+ port->ops = &mlb_usio_ops;
+ port->dev = &pdev->dev;
+
+ ret = uart_add_one_port(&mlb_usio_uart_driver, port);
+ if (ret) {
+ dev_err(&pdev->dev, "Adding port failed: %d\n", ret);
+ goto failed1;
+ }
+ return 0;
+
+failed1:
+ iounmap(port->membase);
+
+failed:
+ clk_disable_unprepare(clk);
+ clk_put(clk);
+
+ return ret;
+}
+
+static int mlb_usio_remove(struct platform_device *pdev)
+{
+ struct uart_port *port = &mlb_usio_ports[pdev->id];
+ struct clk *clk = port->private_data;
+
+ uart_remove_one_port(&mlb_usio_uart_driver, port);
+ clk_disable_unprepare(clk);
+ clk_put(clk);
+
+ return 0;
+}
+
+static const struct of_device_id mlb_usio_dt_ids[] = {
+ { .compatible = "socionext,milbeaut-usio-uart" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mlb_usio_dt_ids);
+
+static struct platform_driver mlb_usio_driver = {
+ .probe = mlb_usio_probe,
+ .remove = mlb_usio_remove,
+ .driver = {
+ .name = USIO_NAME,
+ .of_match_table = mlb_usio_dt_ids,
+ },
+};
+
+static int __init mlb_usio_init(void)
+{
+ int ret = uart_register_driver(&mlb_usio_uart_driver);
+
+ if (ret) {
+ pr_err("%s: uart registration failed: %d\n", __func__, ret);
+ return ret;
+ }
+ ret = platform_driver_register(&mlb_usio_driver);
+ if (ret) {
+ uart_unregister_driver(&mlb_usio_uart_driver);
+ pr_err("%s: drv registration failed: %d\n", __func__, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void __exit mlb_usio_exit(void)
+{
+ platform_driver_unregister(&mlb_usio_driver);
+ uart_unregister_driver(&mlb_usio_uart_driver);
+}
+
+module_init(mlb_usio_init);
+module_exit(mlb_usio_exit);
+
+MODULE_AUTHOR("SOCIONEXT");
+MODULE_DESCRIPTION("MILBEAUT_USIO/UART Driver");
+MODULE_LICENSE("GPL");
projects / linux.git / commitdiff