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Diffstat (limited to 'drivers/tty/serial/apbuart.c')
-rw-r--r--drivers/tty/serial/apbuart.c662
1 files changed, 662 insertions, 0 deletions
diff --git a/drivers/tty/serial/apbuart.c b/drivers/tty/serial/apbuart.c
new file mode 100644
index 0000000000..d3cb341f2c
--- /dev/null
+++ b/drivers/tty/serial/apbuart.c
@@ -0,0 +1,662 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for GRLIB serial ports (APBUART)
+ *
+ * Based on linux/drivers/serial/amba.c
+ *
+ * Copyright (C) 2000 Deep Blue Solutions Ltd.
+ * Copyright (C) 2003 Konrad Eisele <eiselekd@web.de>
+ * Copyright (C) 2006 Daniel Hellstrom <daniel@gaisler.com>, Aeroflex Gaisler AB
+ * Copyright (C) 2008 Gilead Kutnick <kutnickg@zin-tech.com>
+ * Copyright (C) 2009 Kristoffer Glembo <kristoffer@gaisler.com>, Aeroflex Gaisler AB
+ */
+
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/kthread.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/serial_core.h>
+#include <asm/irq.h>
+
+#include "apbuart.h"
+
+#define SERIAL_APBUART_MAJOR TTY_MAJOR
+#define SERIAL_APBUART_MINOR 64
+#define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
+
+static void apbuart_tx_chars(struct uart_port *port);
+
+static void apbuart_stop_tx(struct uart_port *port)
+{
+ unsigned int cr;
+
+ cr = UART_GET_CTRL(port);
+ cr &= ~UART_CTRL_TI;
+ UART_PUT_CTRL(port, cr);
+}
+
+static void apbuart_start_tx(struct uart_port *port)
+{
+ unsigned int cr;
+
+ cr = UART_GET_CTRL(port);
+ cr |= UART_CTRL_TI;
+ UART_PUT_CTRL(port, cr);
+
+ if (UART_GET_STATUS(port) & UART_STATUS_THE)
+ apbuart_tx_chars(port);
+}
+
+static void apbuart_stop_rx(struct uart_port *port)
+{
+ unsigned int cr;
+
+ cr = UART_GET_CTRL(port);
+ cr &= ~(UART_CTRL_RI);
+ UART_PUT_CTRL(port, cr);
+}
+
+static void apbuart_rx_chars(struct uart_port *port)
+{
+ unsigned int status, rsr;
+ unsigned int max_chars = port->fifosize;
+ u8 ch, flag;
+
+ status = UART_GET_STATUS(port);
+
+ while (UART_RX_DATA(status) && (max_chars--)) {
+
+ ch = UART_GET_CHAR(port);
+ flag = TTY_NORMAL;
+
+ port->icount.rx++;
+
+ rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
+ UART_PUT_STATUS(port, 0);
+ if (rsr & UART_STATUS_ERR) {
+
+ if (rsr & UART_STATUS_BR) {
+ rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
+ port->icount.brk++;
+ if (uart_handle_break(port))
+ goto ignore_char;
+ } else if (rsr & UART_STATUS_PE) {
+ port->icount.parity++;
+ } else if (rsr & UART_STATUS_FE) {
+ port->icount.frame++;
+ }
+ if (rsr & UART_STATUS_OE)
+ port->icount.overrun++;
+
+ rsr &= port->read_status_mask;
+
+ if (rsr & UART_STATUS_PE)
+ flag = TTY_PARITY;
+ else if (rsr & UART_STATUS_FE)
+ flag = TTY_FRAME;
+ }
+
+ if (uart_handle_sysrq_char(port, ch))
+ goto ignore_char;
+
+ uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
+
+
+ ignore_char:
+ status = UART_GET_STATUS(port);
+ }
+
+ tty_flip_buffer_push(&port->state->port);
+}
+
+static void apbuart_tx_chars(struct uart_port *port)
+{
+ u8 ch;
+
+ uart_port_tx_limited(port, ch, port->fifosize,
+ true,
+ UART_PUT_CHAR(port, ch),
+ ({}));
+}
+
+static irqreturn_t apbuart_int(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ unsigned int status;
+
+ spin_lock(&port->lock);
+
+ status = UART_GET_STATUS(port);
+ if (status & UART_STATUS_DR)
+ apbuart_rx_chars(port);
+ if (status & UART_STATUS_THE)
+ apbuart_tx_chars(port);
+
+ spin_unlock(&port->lock);
+
+ return IRQ_HANDLED;
+}
+
+static unsigned int apbuart_tx_empty(struct uart_port *port)
+{
+ unsigned int status = UART_GET_STATUS(port);
+ return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int apbuart_get_mctrl(struct uart_port *port)
+{
+ /* The GRLIB APBUART handles flow control in hardware */
+ return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ /* The GRLIB APBUART handles flow control in hardware */
+}
+
+static void apbuart_break_ctl(struct uart_port *port, int break_state)
+{
+ /* We don't support sending break */
+}
+
+static int apbuart_startup(struct uart_port *port)
+{
+ int retval;
+ unsigned int cr;
+
+ /* Allocate the IRQ */
+ retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
+ if (retval)
+ return retval;
+
+ /* Finally, enable interrupts */
+ cr = UART_GET_CTRL(port);
+ UART_PUT_CTRL(port,
+ cr | UART_CTRL_RE | UART_CTRL_TE |
+ UART_CTRL_RI | UART_CTRL_TI);
+
+ return 0;
+}
+
+static void apbuart_shutdown(struct uart_port *port)
+{
+ unsigned int cr;
+
+ /* disable all interrupts, disable the port */
+ cr = UART_GET_CTRL(port);
+ UART_PUT_CTRL(port,
+ cr & ~(UART_CTRL_RE | UART_CTRL_TE |
+ UART_CTRL_RI | UART_CTRL_TI));
+
+ /* Free the interrupt */
+ free_irq(port->irq, port);
+}
+
+static void apbuart_set_termios(struct uart_port *port,
+ struct ktermios *termios, const struct ktermios *old)
+{
+ unsigned int cr;
+ unsigned long flags;
+ unsigned int baud, quot;
+
+ /* Ask the core to calculate the divisor for us. */
+ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+ if (baud == 0)
+ panic("invalid baudrate %i\n", port->uartclk / 16);
+
+ /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
+ quot = (uart_get_divisor(port, baud)) * 2;
+ cr = UART_GET_CTRL(port);
+ cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
+
+ if (termios->c_cflag & PARENB) {
+ cr |= UART_CTRL_PE;
+ if ((termios->c_cflag & PARODD))
+ cr |= UART_CTRL_PS;
+ }
+
+ /* Enable flow control. */
+ if (termios->c_cflag & CRTSCTS)
+ cr |= UART_CTRL_FL;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ /* Update the per-port timeout. */
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ port->read_status_mask = UART_STATUS_OE;
+ if (termios->c_iflag & INPCK)
+ port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
+
+ /* Characters to ignore */
+ port->ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
+
+ /* Ignore all characters if CREAD is not set. */
+ if ((termios->c_cflag & CREAD) == 0)
+ port->ignore_status_mask |= UART_DUMMY_RSR_RX;
+
+ /* Set baud rate */
+ quot -= 1;
+ UART_PUT_SCAL(port, quot);
+ UART_PUT_CTRL(port, cr);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *apbuart_type(struct uart_port *port)
+{
+ return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
+}
+
+static void apbuart_release_port(struct uart_port *port)
+{
+ release_mem_region(port->mapbase, 0x100);
+}
+
+static int apbuart_request_port(struct uart_port *port)
+{
+ return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
+ != NULL ? 0 : -EBUSY;
+ return 0;
+}
+
+/* Configure/autoconfigure the port */
+static void apbuart_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE) {
+ port->type = PORT_APBUART;
+ apbuart_request_port(port);
+ }
+}
+
+/* Verify the new serial_struct (for TIOCSSERIAL) */
+static int apbuart_verify_port(struct uart_port *port,
+ struct serial_struct *ser)
+{
+ int ret = 0;
+ if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
+ ret = -EINVAL;
+ if (ser->irq < 0 || ser->irq >= NR_IRQS)
+ ret = -EINVAL;
+ if (ser->baud_base < 9600)
+ ret = -EINVAL;
+ return ret;
+}
+
+static const struct uart_ops grlib_apbuart_ops = {
+ .tx_empty = apbuart_tx_empty,
+ .set_mctrl = apbuart_set_mctrl,
+ .get_mctrl = apbuart_get_mctrl,
+ .stop_tx = apbuart_stop_tx,
+ .start_tx = apbuart_start_tx,
+ .stop_rx = apbuart_stop_rx,
+ .break_ctl = apbuart_break_ctl,
+ .startup = apbuart_startup,
+ .shutdown = apbuart_shutdown,
+ .set_termios = apbuart_set_termios,
+ .type = apbuart_type,
+ .release_port = apbuart_release_port,
+ .request_port = apbuart_request_port,
+ .config_port = apbuart_config_port,
+ .verify_port = apbuart_verify_port,
+};
+
+static struct uart_port grlib_apbuart_ports[UART_NR];
+static struct device_node *grlib_apbuart_nodes[UART_NR];
+
+static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
+{
+ int ctrl, loop = 0;
+ int status;
+ int fifosize;
+ unsigned long flags;
+
+ ctrl = UART_GET_CTRL(port);
+
+ /*
+ * Enable the transceiver and wait for it to be ready to send data.
+ * Clear interrupts so that this process will not be externally
+ * interrupted in the middle (which can cause the transceiver to
+ * drain prematurely).
+ */
+
+ local_irq_save(flags);
+
+ UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
+
+ while (!UART_TX_READY(UART_GET_STATUS(port)))
+ loop++;
+
+ /*
+ * Disable the transceiver so data isn't actually sent during the
+ * actual test.
+ */
+
+ UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
+
+ fifosize = 1;
+ UART_PUT_CHAR(port, 0);
+
+ /*
+ * So long as transmitting a character increments the tranceivier FIFO
+ * length the FIFO must be at least that big. These bytes will
+ * automatically drain off of the FIFO.
+ */
+
+ status = UART_GET_STATUS(port);
+ while (((status >> 20) & 0x3F) == fifosize) {
+ fifosize++;
+ UART_PUT_CHAR(port, 0);
+ status = UART_GET_STATUS(port);
+ }
+
+ fifosize--;
+
+ UART_PUT_CTRL(port, ctrl);
+ local_irq_restore(flags);
+
+ if (fifosize == 0)
+ fifosize = 1;
+
+ return fifosize;
+}
+
+static void apbuart_flush_fifo(struct uart_port *port)
+{
+ int i;
+
+ for (i = 0; i < port->fifosize; i++)
+ UART_GET_CHAR(port);
+}
+
+
+/* ======================================================================== */
+/* Console driver, if enabled */
+/* ======================================================================== */
+
+#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
+
+static void apbuart_console_putchar(struct uart_port *port, unsigned char ch)
+{
+ unsigned int status;
+ do {
+ status = UART_GET_STATUS(port);
+ } while (!UART_TX_READY(status));
+ UART_PUT_CHAR(port, ch);
+}
+
+static void
+apbuart_console_write(struct console *co, const char *s, unsigned int count)
+{
+ struct uart_port *port = &grlib_apbuart_ports[co->index];
+ unsigned int status, old_cr, new_cr;
+
+ /* First save the CR then disable the interrupts */
+ old_cr = UART_GET_CTRL(port);
+ new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
+ UART_PUT_CTRL(port, new_cr);
+
+ uart_console_write(port, s, count, apbuart_console_putchar);
+
+ /*
+ * Finally, wait for transmitter to become empty
+ * and restore the TCR
+ */
+ do {
+ status = UART_GET_STATUS(port);
+ } while (!UART_TX_READY(status));
+ UART_PUT_CTRL(port, old_cr);
+}
+
+static void __init
+apbuart_console_get_options(struct uart_port *port, int *baud,
+ int *parity, int *bits)
+{
+ if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
+
+ unsigned int quot, status;
+ status = UART_GET_STATUS(port);
+
+ *parity = 'n';
+ if (status & UART_CTRL_PE) {
+ if ((status & UART_CTRL_PS) == 0)
+ *parity = 'e';
+ else
+ *parity = 'o';
+ }
+
+ *bits = 8;
+ quot = UART_GET_SCAL(port) / 8;
+ *baud = port->uartclk / (16 * (quot + 1));
+ }
+}
+
+static int __init apbuart_console_setup(struct console *co, char *options)
+{
+ struct uart_port *port;
+ int baud = 38400;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
+ co, co->index, options);
+
+ /*
+ * 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 >= grlib_apbuart_port_nr)
+ co->index = 0;
+
+ port = &grlib_apbuart_ports[co->index];
+
+ spin_lock_init(&port->lock);
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+ else
+ apbuart_console_get_options(port, &baud, &parity, &bits);
+
+ return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver grlib_apbuart_driver;
+
+static struct console grlib_apbuart_console = {
+ .name = "ttyS",
+ .write = apbuart_console_write,
+ .device = uart_console_device,
+ .setup = apbuart_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &grlib_apbuart_driver,
+};
+
+
+static int grlib_apbuart_configure(void);
+
+static int __init apbuart_console_init(void)
+{
+ if (grlib_apbuart_configure())
+ return -ENODEV;
+ register_console(&grlib_apbuart_console);
+ return 0;
+}
+
+console_initcall(apbuart_console_init);
+
+#define APBUART_CONSOLE (&grlib_apbuart_console)
+#else
+#define APBUART_CONSOLE NULL
+#endif
+
+static struct uart_driver grlib_apbuart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = "serial",
+ .dev_name = "ttyS",
+ .major = SERIAL_APBUART_MAJOR,
+ .minor = SERIAL_APBUART_MINOR,
+ .nr = UART_NR,
+ .cons = APBUART_CONSOLE,
+};
+
+
+/* ======================================================================== */
+/* OF Platform Driver */
+/* ======================================================================== */
+
+static int apbuart_probe(struct platform_device *op)
+{
+ int i;
+ struct uart_port *port = NULL;
+
+ for (i = 0; i < grlib_apbuart_port_nr; i++) {
+ if (op->dev.of_node == grlib_apbuart_nodes[i])
+ break;
+ }
+
+ port = &grlib_apbuart_ports[i];
+ port->dev = &op->dev;
+ port->irq = op->archdata.irqs[0];
+
+ uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
+
+ apbuart_flush_fifo((struct uart_port *) port);
+
+ printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
+ (unsigned long long) port->mapbase, port->irq);
+ return 0;
+}
+
+static const struct of_device_id apbuart_match[] = {
+ {
+ .name = "GAISLER_APBUART",
+ },
+ {
+ .name = "01_00c",
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, apbuart_match);
+
+static struct platform_driver grlib_apbuart_of_driver = {
+ .probe = apbuart_probe,
+ .driver = {
+ .name = "grlib-apbuart",
+ .of_match_table = apbuart_match,
+ },
+};
+
+
+static int __init grlib_apbuart_configure(void)
+{
+ struct device_node *np;
+ int line = 0;
+
+ for_each_matching_node(np, apbuart_match) {
+ const int *ampopts;
+ const u32 *freq_hz;
+ const struct amba_prom_registers *regs;
+ struct uart_port *port;
+ unsigned long addr;
+
+ ampopts = of_get_property(np, "ampopts", NULL);
+ if (ampopts && (*ampopts == 0))
+ continue; /* Ignore if used by another OS instance */
+ regs = of_get_property(np, "reg", NULL);
+ /* Frequency of APB Bus is frequency of UART */
+ freq_hz = of_get_property(np, "freq", NULL);
+
+ if (!regs || !freq_hz || (*freq_hz == 0))
+ continue;
+
+ grlib_apbuart_nodes[line] = np;
+
+ addr = regs->phys_addr;
+
+ port = &grlib_apbuart_ports[line];
+
+ port->mapbase = addr;
+ port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
+ port->irq = 0;
+ port->iotype = UPIO_MEM;
+ port->ops = &grlib_apbuart_ops;
+ port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE);
+ port->flags = UPF_BOOT_AUTOCONF;
+ port->line = line;
+ port->uartclk = *freq_hz;
+ port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
+ line++;
+
+ /* We support maximum UART_NR uarts ... */
+ if (line == UART_NR)
+ break;
+ }
+
+ grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
+ return line ? 0 : -ENODEV;
+}
+
+static int __init grlib_apbuart_init(void)
+{
+ int ret;
+
+ /* Find all APBUARTS in device the tree and initialize their ports */
+ ret = grlib_apbuart_configure();
+ if (ret)
+ return ret;
+
+ printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
+
+ ret = uart_register_driver(&grlib_apbuart_driver);
+
+ if (ret) {
+ printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
+ __FILE__, ret);
+ return ret;
+ }
+
+ ret = platform_driver_register(&grlib_apbuart_of_driver);
+ if (ret) {
+ printk(KERN_ERR
+ "%s: platform_driver_register failed (%i)\n",
+ __FILE__, ret);
+ uart_unregister_driver(&grlib_apbuart_driver);
+ return ret;
+ }
+
+ return ret;
+}
+
+static void __exit grlib_apbuart_exit(void)
+{
+ int i;
+
+ for (i = 0; i < grlib_apbuart_port_nr; i++)
+ uart_remove_one_port(&grlib_apbuart_driver,
+ &grlib_apbuart_ports[i]);
+
+ uart_unregister_driver(&grlib_apbuart_driver);
+ platform_driver_unregister(&grlib_apbuart_of_driver);
+}
+
+module_init(grlib_apbuart_init);
+module_exit(grlib_apbuart_exit);
+
+MODULE_AUTHOR("Aeroflex Gaisler AB");
+MODULE_DESCRIPTION("GRLIB APBUART serial driver");
+MODULE_VERSION("2.1");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 14:34:12 +0000