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path: root/drivers/tty/serial/mvebu-uart.c
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Diffstat (limited to 'drivers/tty/serial/mvebu-uart.c')
-rw-r--r--drivers/tty/serial/mvebu-uart.c650
1 files changed, 650 insertions, 0 deletions
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
new file mode 100644
index 000000000..0ff27818b
--- /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");
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-05 03:22:42 +0000