diff options
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/Kconfig | 22 | ||||
| -rw-r--r-- | drivers/tty/serial/Makefile | 1 | ||||
| -rw-r--r-- | drivers/tty/serial/mvebu-uart.c | 650 |
3 files changed, 673 insertions, 0 deletions
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index de2481cf6e58..13d4ed6caac4 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1602,6 +1602,28 @@ config SERIAL_STM32_CONSOLE depends on SERIAL_STM32=y select SERIAL_CORE_CONSOLE +config SERIAL_MVEBU_UART + bool "Marvell EBU serial port support" + select SERIAL_CORE + help + This driver is for Marvell EBU SoC's UART. If you have a machine + based on the Armada-3700 SoC and wish to use the on-board serial + port, + say 'Y' here. + Otherwise, say 'N'. + +config SERIAL_MVEBU_CONSOLE + bool "Console on Marvell EBU serial port" + depends on SERIAL_MVEBU_UART + select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON + default y + help + Say 'Y' here if you wish to use Armada-3700 UART as the system console. + (the system console is the device which receives all kernel messages + and warnings and which allows logins in single user mode) + Otherwise, say 'N'. + endmenu config SERIAL_MCTRL_GPIO diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index ceba33c4ebb4..8c261adac04e 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -90,6 +90,7 @@ obj-$(CONFIG_SERIAL_CONEXANT_DIGICOLOR) += digicolor-usart.o obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o obj-$(CONFIG_SERIAL_STM32) += stm32-usart.o +obj-$(CONFIG_SERIAL_MVEBU_UART) += mvebu-uart.o # GPIOLIB helpers for modem control lines obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c new file mode 100644 index 000000000000..0ff27818bb87 --- /dev/null +++ b/drivers/tty/serial/mvebu-uart.c @@ -0,0 +1,650 @@ +/* +* *************************************************************************** +* Copyright (C) 2015 Marvell International Ltd. +* *************************************************************************** +* 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, either version 2 of the License, or any later version. +* +* 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, see <http://www.gnu.org/licenses/>. +* *************************************************************************** +*/ + +#include <linux/clk.h> +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/serial.h> +#include <linux/serial_core.h> +#include <linux/slab.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> + +/* Register Map */ +#define UART_RBR 0x00 +#define RBR_BRK_DET BIT(15) +#define RBR_FRM_ERR_DET BIT(14) +#define RBR_PAR_ERR_DET BIT(13) +#define RBR_OVR_ERR_DET BIT(12) + +#define UART_TSH 0x04 + +#define UART_CTRL 0x08 +#define CTRL_SOFT_RST BIT(31) +#define CTRL_TXFIFO_RST BIT(15) +#define CTRL_RXFIFO_RST BIT(14) +#define CTRL_ST_MIRR_EN BIT(13) +#define CTRL_LPBK_EN BIT(12) +#define CTRL_SND_BRK_SEQ BIT(11) +#define CTRL_PAR_EN BIT(10) +#define CTRL_TWO_STOP BIT(9) +#define CTRL_TX_HFL_INT BIT(8) +#define CTRL_RX_HFL_INT BIT(7) +#define CTRL_TX_EMP_INT BIT(6) +#define CTRL_TX_RDY_INT BIT(5) +#define CTRL_RX_RDY_INT BIT(4) +#define CTRL_BRK_DET_INT BIT(3) +#define CTRL_FRM_ERR_INT BIT(2) +#define CTRL_PAR_ERR_INT BIT(1) +#define CTRL_OVR_ERR_INT BIT(0) +#define CTRL_RX_INT (CTRL_RX_RDY_INT | CTRL_BRK_DET_INT |\ + CTRL_FRM_ERR_INT | CTRL_PAR_ERR_INT | CTRL_OVR_ERR_INT) + +#define UART_STAT 0x0c +#define STAT_TX_FIFO_EMP BIT(13) +#define STAT_RX_FIFO_EMP BIT(12) +#define STAT_TX_FIFO_FUL BIT(11) +#define STAT_TX_FIFO_HFL BIT(10) +#define STAT_RX_TOGL BIT(9) +#define STAT_RX_FIFO_FUL BIT(8) +#define STAT_RX_FIFO_HFL BIT(7) +#define STAT_TX_EMP BIT(6) +#define STAT_TX_RDY BIT(5) +#define STAT_RX_RDY BIT(4) +#define STAT_BRK_DET BIT(3) +#define STAT_FRM_ERR BIT(2) +#define STAT_PAR_ERR BIT(1) +#define STAT_OVR_ERR BIT(0) +#define STAT_BRK_ERR (STAT_BRK_DET | STAT_FRM_ERR | STAT_FRM_ERR\ + | STAT_PAR_ERR | STAT_OVR_ERR) + +#define UART_BRDV 0x10 + +#define MVEBU_NR_UARTS 1 + +#define MVEBU_UART_TYPE "mvebu-uart" + +static struct uart_port mvebu_uart_ports[MVEBU_NR_UARTS]; + +struct mvebu_uart_data { + struct uart_port *port; + struct clk *clk; +}; + +/* Core UART Driver Operations */ +static unsigned int mvebu_uart_tx_empty(struct uart_port *port) +{ + unsigned long flags; + unsigned int st; + + spin_lock_irqsave(&port->lock, flags); + st = readl(port->membase + UART_STAT); + spin_unlock_irqrestore(&port->lock, flags); + + return (st & STAT_TX_FIFO_EMP) ? TIOCSER_TEMT : 0; +} + +static unsigned int mvebu_uart_get_mctrl(struct uart_port *port) +{ + return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR; +} + +static void mvebu_uart_set_mctrl(struct uart_port *port, + unsigned int mctrl) +{ +/* + * Even if we do not support configuring the modem control lines, this + * function must be proided to the serial core + */ +} + +static void mvebu_uart_stop_tx(struct uart_port *port) +{ + unsigned int ctl = readl(port->membase + UART_CTRL); + + ctl &= ~CTRL_TX_RDY_INT; + writel(ctl, port->membase + UART_CTRL); +} + +static void mvebu_uart_start_tx(struct uart_port *port) +{ + unsigned int ctl = readl(port->membase + UART_CTRL); + + ctl |= CTRL_TX_RDY_INT; + writel(ctl, port->membase + UART_CTRL); +} + +static void mvebu_uart_stop_rx(struct uart_port *port) +{ + unsigned int ctl = readl(port->membase + UART_CTRL); + + ctl &= ~CTRL_RX_INT; + writel(ctl, port->membase + UART_CTRL); +} + +static void mvebu_uart_break_ctl(struct uart_port *port, int brk) +{ + unsigned int ctl; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + ctl = readl(port->membase + UART_CTRL); + if (brk == -1) + ctl |= CTRL_SND_BRK_SEQ; + else + ctl &= ~CTRL_SND_BRK_SEQ; + writel(ctl, port->membase + UART_CTRL); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status) +{ + struct tty_port *tport = &port->state->port; + unsigned char ch = 0; + char flag = 0; + + do { + if (status & STAT_RX_RDY) { + ch = readl(port->membase + UART_RBR); + ch &= 0xff; + flag = TTY_NORMAL; + port->icount.rx++; + + if (status & STAT_PAR_ERR) + port->icount.parity++; + } + + if (status & STAT_BRK_DET) { + port->icount.brk++; + status &= ~(STAT_FRM_ERR | STAT_PAR_ERR); + if (uart_handle_break(port)) + goto ignore_char; + } + + if (status & STAT_OVR_ERR) + port->icount.overrun++; + + if (status & STAT_FRM_ERR) + port->icount.frame++; + + if (uart_handle_sysrq_char(port, ch)) + goto ignore_char; + + if (status & port->ignore_status_mask & STAT_PAR_ERR) + status &= ~STAT_RX_RDY; + + status &= port->read_status_mask; + + if (status & STAT_PAR_ERR) + flag = TTY_PARITY; + + status &= ~port->ignore_status_mask; + + if (status & STAT_RX_RDY) + tty_insert_flip_char(tport, ch, flag); + + if (status & STAT_BRK_DET) + tty_insert_flip_char(tport, 0, TTY_BREAK); + + if (status & STAT_FRM_ERR) + tty_insert_flip_char(tport, 0, TTY_FRAME); + + if (status & STAT_OVR_ERR) + tty_insert_flip_char(tport, 0, TTY_OVERRUN); + +ignore_char: + status = readl(port->membase + UART_STAT); + } while (status & (STAT_RX_RDY | STAT_BRK_DET)); + + tty_flip_buffer_push(tport); +} + +static void mvebu_uart_tx_chars(struct uart_port *port, unsigned int status) +{ + struct circ_buf *xmit = &port->state->xmit; + unsigned int count; + unsigned int st; + + if (port->x_char) { + writel(port->x_char, port->membase + UART_TSH); + port->icount.tx++; + port->x_char = 0; + return; + } + + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { + mvebu_uart_stop_tx(port); + return; + } + + for (count = 0; count < port->fifosize; count++) { + writel(xmit->buf[xmit->tail], port->membase + UART_TSH); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + + if (uart_circ_empty(xmit)) + break; + + st = readl(port->membase + UART_STAT); + if (st & STAT_TX_FIFO_FUL) + break; + } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + if (uart_circ_empty(xmit)) + mvebu_uart_stop_tx(port); +} + +static irqreturn_t mvebu_uart_isr(int irq, void *dev_id) +{ + struct uart_port *port = (struct uart_port *)dev_id; + unsigned int st = readl(port->membase + UART_STAT); + + if (st & (STAT_RX_RDY | STAT_OVR_ERR | STAT_FRM_ERR | STAT_BRK_DET)) + mvebu_uart_rx_chars(port, st); + + if (st & STAT_TX_RDY) + mvebu_uart_tx_chars(port, st); + + return IRQ_HANDLED; +} + +static int mvebu_uart_startup(struct uart_port *port) +{ + int ret; + + writel(CTRL_TXFIFO_RST | CTRL_RXFIFO_RST, + port->membase + UART_CTRL); + udelay(1); + writel(CTRL_RX_INT, port->membase + UART_CTRL); + + ret = request_irq(port->irq, mvebu_uart_isr, port->irqflags, "serial", + port); + if (ret) { + dev_err(port->dev, "failed to request irq\n"); + return ret; + } + + return 0; +} + +static void mvebu_uart_shutdown(struct uart_port *port) +{ + writel(0, port->membase + UART_CTRL); +} + +static void mvebu_uart_set_termios(struct uart_port *port, + struct ktermios *termios, + struct ktermios *old) +{ + unsigned long flags; + unsigned int baud; + + spin_lock_irqsave(&port->lock, flags); + + port->read_status_mask = STAT_RX_RDY | STAT_OVR_ERR | + STAT_TX_RDY | STAT_TX_FIFO_FUL; + + if (termios->c_iflag & INPCK) + port->read_status_mask |= STAT_FRM_ERR | STAT_PAR_ERR; + + port->ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + port->ignore_status_mask |= + STAT_FRM_ERR | STAT_PAR_ERR | STAT_OVR_ERR; + + if ((termios->c_cflag & CREAD) == 0) + port->ignore_status_mask |= STAT_RX_RDY | STAT_BRK_ERR; + + if (old) + tty_termios_copy_hw(termios, old); + + baud = uart_get_baud_rate(port, termios, old, 0, 460800); + uart_update_timeout(port, termios->c_cflag, baud); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *mvebu_uart_type(struct uart_port *port) +{ + return MVEBU_UART_TYPE; +} + +static void mvebu_uart_release_port(struct uart_port *port) +{ + /* Nothing to do here */ +} + +static int mvebu_uart_request_port(struct uart_port *port) +{ + return 0; +} + +#ifdef CONFIG_CONSOLE_POLL +static int mvebu_uart_get_poll_char(struct uart_port *port) +{ + unsigned int st = readl(port->membase + UART_STAT); + + if (!(st & STAT_RX_RDY)) + return NO_POLL_CHAR; + + return readl(port->membase + UART_RBR); +} + +static void mvebu_uart_put_poll_char(struct uart_port *port, unsigned char c) +{ + unsigned int st; + + for (;;) { + st = readl(port->membase + UART_STAT); + + if (!(st & STAT_TX_FIFO_FUL)) + break; + + udelay(1); + } + + writel(c, port->membase + UART_TSH); +} +#endif + +static const struct uart_ops mvebu_uart_ops = { + .tx_empty = mvebu_uart_tx_empty, + .set_mctrl = mvebu_uart_set_mctrl, + .get_mctrl = mvebu_uart_get_mctrl, + .stop_tx = mvebu_uart_stop_tx, + .start_tx = mvebu_uart_start_tx, + .stop_rx = mvebu_uart_stop_rx, + .break_ctl = mvebu_uart_break_ctl, + .startup = mvebu_uart_startup, + .shutdown = mvebu_uart_shutdown, + .set_termios = mvebu_uart_set_termios, + .type = mvebu_uart_type, + .release_port = mvebu_uart_release_port, + .request_port = mvebu_uart_request_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = mvebu_uart_get_poll_char, + .poll_put_char = mvebu_uart_put_poll_char, +#endif +}; + +/* Console Driver Operations */ + +#ifdef CONFIG_SERIAL_MVEBU_CONSOLE +/* Early Console */ +static void mvebu_uart_putc(struct uart_port *port, int c) +{ + unsigned int st; + + for (;;) { + st = readl(port->membase + UART_STAT); + if (!(st & STAT_TX_FIFO_FUL)) + break; + } + + writel(c, port->membase + UART_TSH); + + for (;;) { + st = readl(port->membase + UART_STAT); + if (st & STAT_TX_FIFO_EMP) + break; + } +} + +static void mvebu_uart_putc_early_write(struct console *con, + const char *s, + unsigned n) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, n, mvebu_uart_putc); +} + +static int __init +mvebu_uart_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = mvebu_uart_putc_early_write; + + return 0; +} + +EARLYCON_DECLARE(ar3700_uart, mvebu_uart_early_console_setup); +OF_EARLYCON_DECLARE(ar3700_uart, "marvell,armada-3700-uart", + mvebu_uart_early_console_setup); + +static void wait_for_xmitr(struct uart_port *port) +{ + u32 val; + + readl_poll_timeout_atomic(port->membase + UART_STAT, val, + (val & STAT_TX_EMP), 1, 10000); +} + +static void mvebu_uart_console_putchar(struct uart_port *port, int ch) +{ + wait_for_xmitr(port); + writel(ch, port->membase + UART_TSH); +} + +static void mvebu_uart_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct uart_port *port = &mvebu_uart_ports[co->index]; + unsigned long flags; + unsigned int ier; + int locked = 1; + + if (oops_in_progress) + locked = spin_trylock_irqsave(&port->lock, flags); + else + spin_lock_irqsave(&port->lock, flags); + + ier = readl(port->membase + UART_CTRL) & + (CTRL_RX_INT | CTRL_TX_RDY_INT); + writel(0, port->membase + UART_CTRL); + + uart_console_write(port, s, count, mvebu_uart_console_putchar); + + wait_for_xmitr(port); + + if (ier) + writel(ier, port->membase + UART_CTRL); + + if (locked) + spin_unlock_irqrestore(&port->lock, flags); +} + +static int mvebu_uart_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int baud = 9600; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (co->index < 0 || co->index >= MVEBU_NR_UARTS) + return -EINVAL; + + port = &mvebu_uart_ports[co->index]; + + if (!port->mapbase || !port->membase) { + pr_debug("console on ttyMV%i not present\n", co->index); + return -ENODEV; + } + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct uart_driver mvebu_uart_driver; + +static struct console mvebu_uart_console = { + .name = "ttyMV", + .write = mvebu_uart_console_write, + .device = uart_console_device, + .setup = mvebu_uart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &mvebu_uart_driver, +}; + +static int __init mvebu_uart_console_init(void) +{ + register_console(&mvebu_uart_console); + return 0; +} + +console_initcall(mvebu_uart_console_init); + + +#endif /* CONFIG_SERIAL_MVEBU_CONSOLE */ + +static struct uart_driver mvebu_uart_driver = { + .owner = THIS_MODULE, + .driver_name = "mvebu_serial", + .dev_name = "ttyMV", + .nr = MVEBU_NR_UARTS, +#ifdef CONFIG_SERIAL_MVEBU_CONSOLE + .cons = &mvebu_uart_console, +#endif +}; + +static int mvebu_uart_probe(struct platform_device *pdev) +{ + struct resource *reg = platform_get_resource(pdev, IORESOURCE_MEM, 0); + struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + struct uart_port *port; + struct mvebu_uart_data *data; + int ret; + + if (!reg || !irq) { + dev_err(&pdev->dev, "no registers/irq defined\n"); + return -EINVAL; + } + + port = &mvebu_uart_ports[0]; + + spin_lock_init(&port->lock); + + port->dev = &pdev->dev; + port->type = PORT_MVEBU; + port->ops = &mvebu_uart_ops; + port->regshift = 0; + + port->fifosize = 32; + port->iotype = UPIO_MEM32; + port->flags = UPF_FIXED_PORT; + port->line = 0; /* single port: force line number to 0 */ + + port->irq = irq->start; + port->irqflags = 0; + port->mapbase = reg->start; + + port->membase = devm_ioremap_resource(&pdev->dev, reg); + if (IS_ERR(port->membase)) + return -PTR_ERR(port->membase); + + data = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_uart_data), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->port = port; + + port->private_data = data; + platform_set_drvdata(pdev, data); + + ret = uart_add_one_port(&mvebu_uart_driver, port); + if (ret) + return ret; + return 0; +} + +static int mvebu_uart_remove(struct platform_device *pdev) +{ + struct mvebu_uart_data *data = platform_get_drvdata(pdev); + + uart_remove_one_port(&mvebu_uart_driver, data->port); + data->port->private_data = NULL; + data->port->mapbase = 0; + return 0; +} + +/* Match table for of_platform binding */ +static const struct of_device_id mvebu_uart_of_match[] = { + { .compatible = "marvell,armada-3700-uart", }, + {} +}; +MODULE_DEVICE_TABLE(of, mvebu_uart_of_match); + +static struct platform_driver mvebu_uart_platform_driver = { + .probe = mvebu_uart_probe, + .remove = mvebu_uart_remove, + .driver = { + .owner = THIS_MODULE, + .name = "mvebu-uart", + .of_match_table = of_match_ptr(mvebu_uart_of_match), + }, +}; + +static int __init mvebu_uart_init(void) +{ + int ret; + + ret = uart_register_driver(&mvebu_uart_driver); + if (ret) + return ret; + + ret = platform_driver_register(&mvebu_uart_platform_driver); + if (ret) + uart_unregister_driver(&mvebu_uart_driver); + + return ret; +} + +static void __exit mvebu_uart_exit(void) +{ + platform_driver_unregister(&mvebu_uart_platform_driver); + uart_unregister_driver(&mvebu_uart_driver); +} + +arch_initcall(mvebu_uart_init); +module_exit(mvebu_uart_exit); + +MODULE_AUTHOR("Wilson Ding <dingwei@marvell.com>"); +MODULE_DESCRIPTION("Marvell Armada-3700 Serial Driver"); +MODULE_LICENSE("GPL"); |