--- /dev/null
+/*
+ * uartlite.c: Serial driver for Xilinx uartlite serial controller
+ *
+ * Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk>
+ * Copyright (C) 2007 Secret Lab Technologies Ltd.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+
+#define ULITE_NAME "ttyUL"
+#define ULITE_MAJOR 204
+#define ULITE_MINOR 187
+#define ULITE_NR_UARTS 4
+
+/* ---------------------------------------------------------------------
+ * Register definitions
+ *
+ * For register details see datasheet:
+ * http://www.xilinx.com/support/documentation/ip_documentation/opb_uartlite.pdf
+ */
+
+#define ULITE_RX 0x00
+#define ULITE_TX 0x04
+#define ULITE_STATUS 0x08
+#define ULITE_CONTROL 0x0c
+
+#define ULITE_REGION 16
+
+#define ULITE_STATUS_RXVALID 0x01
+#define ULITE_STATUS_RXFULL 0x02
+#define ULITE_STATUS_TXEMPTY 0x04
+#define ULITE_STATUS_TXFULL 0x08
+#define ULITE_STATUS_IE 0x10
+#define ULITE_STATUS_OVERRUN 0x20
+#define ULITE_STATUS_FRAME 0x40
+#define ULITE_STATUS_PARITY 0x80
+
+#define ULITE_CONTROL_RST_TX 0x01
+#define ULITE_CONTROL_RST_RX 0x02
+#define ULITE_CONTROL_IE 0x10
+
+struct uartlite_reg_ops {
+ u32 (*in)(void __iomem *addr);
+ void (*out)(u32 val, void __iomem *addr);
+};
+
+static u32 uartlite_inbe32(void __iomem *addr)
+{
+ return ioread32be(addr);
+}
+
+static void uartlite_outbe32(u32 val, void __iomem *addr)
+{
+ iowrite32be(val, addr);
+}
+
+static struct uartlite_reg_ops uartlite_be = {
+ .in = uartlite_inbe32,
+ .out = uartlite_outbe32,
+};
+
+static u32 uartlite_inle32(void __iomem *addr)
+{
+ return ioread32(addr);
+}
+
+static void uartlite_outle32(u32 val, void __iomem *addr)
+{
+ iowrite32(val, addr);
+}
+
+static struct uartlite_reg_ops uartlite_le = {
+ .in = uartlite_inle32,
+ .out = uartlite_outle32,
+};
+
+static inline u32 uart_in32(u32 offset, struct uart_port *port)
+{
+ struct uartlite_reg_ops *reg_ops = port->private_data;
+
+ return reg_ops->in(port->membase + offset);
+}
+
+static inline void uart_out32(u32 val, u32 offset, struct uart_port *port)
+{
+ struct uartlite_reg_ops *reg_ops = port->private_data;
+
+ reg_ops->out(val, port->membase + offset);
+}
+
+static struct uart_port ulite_ports[ULITE_NR_UARTS];
+
+/* ---------------------------------------------------------------------
+ * Core UART driver operations
+ */
+
+static int ulite_receive(struct uart_port *port, int stat)
+{
+ struct tty_port *tport = &port->state->port;
+ unsigned char ch = 0;
+ char flag = TTY_NORMAL;
+
+ if ((stat & (ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
+ | ULITE_STATUS_FRAME)) == 0)
+ return 0;
+
+ /* stats */
+ if (stat & ULITE_STATUS_RXVALID) {
+ port->icount.rx++;
+ ch = uart_in32(ULITE_RX, port);
+
+ if (stat & ULITE_STATUS_PARITY)
+ port->icount.parity++;
+ }
+
+ if (stat & ULITE_STATUS_OVERRUN)
+ port->icount.overrun++;
+
+ if (stat & ULITE_STATUS_FRAME)
+ port->icount.frame++;
+
+
+ /* drop byte with parity error if IGNPAR specificed */
+ if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
+ stat &= ~ULITE_STATUS_RXVALID;
+
+ stat &= port->read_status_mask;
+
+ if (stat & ULITE_STATUS_PARITY)
+ flag = TTY_PARITY;
+
+
+ stat &= ~port->ignore_status_mask;
+
+ if (stat & ULITE_STATUS_RXVALID)
+ tty_insert_flip_char(tport, ch, flag);
+
+ if (stat & ULITE_STATUS_FRAME)
+ tty_insert_flip_char(tport, 0, TTY_FRAME);
+
+ if (stat & ULITE_STATUS_OVERRUN)
+ tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+
+ return 1;
+}
+
+static int ulite_transmit(struct uart_port *port, int stat)
+{
+ struct circ_buf *xmit = &port->state->xmit;
+
+ if (stat & ULITE_STATUS_TXFULL)
+ return 0;
+
+ if (port->x_char) {
+ uart_out32(port->x_char, ULITE_TX, port);
+ port->x_char = 0;
+ port->icount.tx++;
+ return 1;
+ }
+
+ if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+ return 0;
+
+ uart_out32(xmit->buf[xmit->tail], ULITE_TX, port);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
+ port->icount.tx++;
+
+ /* wake up */
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+
+ return 1;
+}
+
+static irqreturn_t ulite_isr(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ int busy, n = 0;
+
+ do {
+ int stat = uart_in32(ULITE_STATUS, port);
+ busy = ulite_receive(port, stat);
+ busy |= ulite_transmit(port, stat);
+ n++;
+ } while (busy);
+
+ /* work done? */
+ if (n > 1) {
+ tty_flip_buffer_push(&port->state->port);
+ return IRQ_HANDLED;
+ } else {
+ return IRQ_NONE;
+ }
+}
+
+static unsigned int ulite_tx_empty(struct uart_port *port)
+{
+ unsigned long flags;
+ unsigned int ret;
+
+ spin_lock_irqsave(&port->lock, flags);
+ ret = uart_in32(ULITE_STATUS, port);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int ulite_get_mctrl(struct uart_port *port)
+{
+ return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+}
+
+static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ /* N/A */
+}
+
+static void ulite_stop_tx(struct uart_port *port)
+{
+ /* N/A */
+}
+
+static void ulite_start_tx(struct uart_port *port)
+{
+ ulite_transmit(port, uart_in32(ULITE_STATUS, port));
+}
+
+static void ulite_stop_rx(struct uart_port *port)
+{
+ /* don't forward any more data (like !CREAD) */
+ port->ignore_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
+ | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
+}
+
+static void ulite_break_ctl(struct uart_port *port, int ctl)
+{
+ /* N/A */
+}
+
+static int ulite_startup(struct uart_port *port)
+{
+ int ret;
+
+ ret = request_irq(port->irq, ulite_isr, IRQF_SHARED, "uartlite", port);
+ if (ret)
+ return ret;
+
+ uart_out32(ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX,
+ ULITE_CONTROL, port);
+ uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
+
+ return 0;
+}
+
+static void ulite_shutdown(struct uart_port *port)
+{
+ uart_out32(0, ULITE_CONTROL, port);
+ uart_in32(ULITE_CONTROL, port); /* dummy */
+ free_irq(port->irq, port);
+}
+
+static void ulite_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 = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
+ | ULITE_STATUS_TXFULL;
+
+ if (termios->c_iflag & INPCK)
+ port->read_status_mask |=
+ ULITE_STATUS_PARITY | ULITE_STATUS_FRAME;
+
+ port->ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= ULITE_STATUS_PARITY
+ | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
+
+ /* ignore all characters if CREAD is not set */
+ if ((termios->c_cflag & CREAD) == 0)
+ port->ignore_status_mask |=
+ ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
+ | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
+
+ /* update timeout */
+ 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 *ulite_type(struct uart_port *port)
+{
+ return port->type == PORT_UARTLITE ? "uartlite" : NULL;
+}
+
+static void ulite_release_port(struct uart_port *port)
+{
+ release_mem_region(port->mapbase, ULITE_REGION);
+ iounmap(port->membase);
+ port->membase = NULL;
+}
+
+static int ulite_request_port(struct uart_port *port)
+{
+ int ret;
+
+ pr_debug("ulite console: port=%p; port->mapbase=%llx\n",
+ port, (unsigned long long) port->mapbase);
+
+ if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
+ dev_err(port->dev, "Memory region busy\n");
+ return -EBUSY;
+ }
+
+ port->membase = ioremap(port->mapbase, ULITE_REGION);
+ if (!port->membase) {
+ dev_err(port->dev, "Unable to map registers\n");
+ release_mem_region(port->mapbase, ULITE_REGION);
+ return -EBUSY;
+ }
+
+ port->private_data = &uartlite_be;
+ ret = uart_in32(ULITE_CONTROL, port);
+ uart_out32(ULITE_CONTROL_RST_TX, ULITE_CONTROL, port);
+ ret = uart_in32(ULITE_STATUS, port);
+ /* Endianess detection */
+ if ((ret & ULITE_STATUS_TXEMPTY) != ULITE_STATUS_TXEMPTY)
+ port->private_data = &uartlite_le;
+
+ return 0;
+}
+
+static void ulite_config_port(struct uart_port *port, int flags)
+{
+ if (!ulite_request_port(port))
+ port->type = PORT_UARTLITE;
+}
+
+static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+ /* we don't want the core code to modify any port params */
+ return -EINVAL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int ulite_get_poll_char(struct uart_port *port)
+{
+ if (!(uart_in32(ULITE_STATUS, port) & ULITE_STATUS_RXVALID))
+ return NO_POLL_CHAR;
+
+ return uart_in32(ULITE_RX, port);
+}
+
+static void ulite_put_poll_char(struct uart_port *port, unsigned char ch)
+{
+ while (uart_in32(ULITE_STATUS, port) & ULITE_STATUS_TXFULL)
+ cpu_relax();
+
+ /* write char to device */
+ uart_out32(ch, ULITE_TX, port);
+}
+#endif
+
+static struct uart_ops ulite_ops = {
+ .tx_empty = ulite_tx_empty,
+ .set_mctrl = ulite_set_mctrl,
+ .get_mctrl = ulite_get_mctrl,
+ .stop_tx = ulite_stop_tx,
+ .start_tx = ulite_start_tx,
+ .stop_rx = ulite_stop_rx,
+ .break_ctl = ulite_break_ctl,
+ .startup = ulite_startup,
+ .shutdown = ulite_shutdown,
+ .set_termios = ulite_set_termios,
+ .type = ulite_type,
+ .release_port = ulite_release_port,
+ .request_port = ulite_request_port,
+ .config_port = ulite_config_port,
+ .verify_port = ulite_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_get_char = ulite_get_poll_char,
+ .poll_put_char = ulite_put_poll_char,
+#endif
+};
+
+/* ---------------------------------------------------------------------
+ * Console driver operations
+ */
+
+#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
+static void ulite_console_wait_tx(struct uart_port *port)
+{
+ u8 val;
+ unsigned long timeout;
+
+ /*
+ * Spin waiting for TX fifo to have space available.
+ * When using the Microblaze Debug Module this can take up to 1s
+ */
+ timeout = jiffies + msecs_to_jiffies(1000);
+ while (1) {
+ val = uart_in32(ULITE_STATUS, port);
+ if ((val & ULITE_STATUS_TXFULL) == 0)
+ break;
+ if (time_after(jiffies, timeout)) {
+ dev_warn(port->dev,
+ "timeout waiting for TX buffer empty\n");
+ break;
+ }
+ cpu_relax();
+ }
+}
+
+static void ulite_console_putchar(struct uart_port *port, int ch)
+{
+ ulite_console_wait_tx(port);
+ uart_out32(ch, ULITE_TX, port);
+}
+
+static void ulite_console_write(struct console *co, const char *s,
+ unsigned int count)
+{
+ struct uart_port *port = &ulite_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);
+
+ /* save and disable interrupt */
+ ier = uart_in32(ULITE_STATUS, port) & ULITE_STATUS_IE;
+ uart_out32(0, ULITE_CONTROL, port);
+
+ uart_console_write(port, s, count, ulite_console_putchar);
+
+ ulite_console_wait_tx(port);
+
+ /* restore interrupt state */
+ if (ier)
+ uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
+
+ if (locked)
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int ulite_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 >= ULITE_NR_UARTS)
+ return -EINVAL;
+
+ port = &ulite_ports[co->index];
+
+ /* Has the device been initialized yet? */
+ if (!port->mapbase) {
+ pr_debug("console on ttyUL%i not present\n", co->index);
+ return -ENODEV;
+ }
+
+ /* not initialized yet? */
+ if (!port->membase) {
+ if (ulite_request_port(port))
+ 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 ulite_uart_driver;
+
+static struct console ulite_console = {
+ .name = ULITE_NAME,
+ .write = ulite_console_write,
+ .device = uart_console_device,
+ .setup = ulite_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
+ .data = &ulite_uart_driver,
+};
+
+static int __init ulite_console_init(void)
+{
+ register_console(&ulite_console);
+ return 0;
+}
+
+console_initcall(ulite_console_init);
+
+#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */
+
+static struct uart_driver ulite_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = "uartlite",
+ .dev_name = ULITE_NAME,
+ .major = ULITE_MAJOR,
+ .minor = ULITE_MINOR,
+ .nr = ULITE_NR_UARTS,
+#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
+ .cons = &ulite_console,
+#endif
+};
+
+/* ---------------------------------------------------------------------
+ * Port assignment functions (mapping devices to uart_port structures)
+ */
+
+/** ulite_assign: register a uartlite device with the driver
+ *
+ * @dev: pointer to device structure
+ * @id: requested id number. Pass -1 for automatic port assignment
+ * @base: base address of uartlite registers
+ * @irq: irq number for uartlite
+ *
+ * Returns: 0 on success, <0 otherwise
+ */
+static int ulite_assign(struct device *dev, int id, u32 base, int irq)
+{
+ struct uart_port *port;
+ int rc;
+
+ /* if id = -1; then scan for a free id and use that */
+ if (id < 0) {
+ for (id = 0; id < ULITE_NR_UARTS; id++)
+ if (ulite_ports[id].mapbase == 0)
+ break;
+ }
+ if (id < 0 || id >= ULITE_NR_UARTS) {
+ dev_err(dev, "%s%i too large\n", ULITE_NAME, id);
+ return -EINVAL;
+ }
+
+ if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) {
+ dev_err(dev, "cannot assign to %s%i; it is already in use\n",
+ ULITE_NAME, id);
+ return -EBUSY;
+ }
+
+ port = &ulite_ports[id];
+
+ spin_lock_init(&port->lock);
+ port->fifosize = 16;
+ port->regshift = 2;
+ port->iotype = UPIO_MEM;
+ port->iobase = 1; /* mark port in use */
+ port->mapbase = base;
+ port->membase = NULL;
+ port->ops = &ulite_ops;
+ port->irq = irq;
+ port->flags = UPF_BOOT_AUTOCONF;
+ port->dev = dev;
+ port->type = PORT_UNKNOWN;
+ port->line = id;
+
+ dev_set_drvdata(dev, port);
+
+ /* Register the port */
+ rc = uart_add_one_port(&ulite_uart_driver, port);
+ if (rc) {
+ dev_err(dev, "uart_add_one_port() failed; err=%i\n", rc);
+ port->mapbase = 0;
+ dev_set_drvdata(dev, NULL);
+ return rc;
+ }
+
+ return 0;
+}
+
+/** ulite_release: register a uartlite device with the driver
+ *
+ * @dev: pointer to device structure
+ */
+static int ulite_release(struct device *dev)
+{
+ struct uart_port *port = dev_get_drvdata(dev);
+ int rc = 0;
+
+ if (port) {
+ rc = uart_remove_one_port(&ulite_uart_driver, port);
+ dev_set_drvdata(dev, NULL);
+ port->mapbase = 0;
+ }
+
+ return rc;
+}
+
+/* ---------------------------------------------------------------------
+ * Platform bus binding
+ */
+
+#if defined(CONFIG_OF)
+/* Match table for of_platform binding */
+static const struct of_device_id ulite_of_match[] = {
+ { .compatible = "xlnx,opb-uartlite-1.00.b", },
+ { .compatible = "xlnx,xps-uartlite-1.00.a", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, ulite_of_match);
+#endif /* CONFIG_OF */
+
+static int ulite_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ int irq;
+ int id = pdev->id;
+#ifdef CONFIG_OF
+ const __be32 *prop;
+
+ prop = of_get_property(pdev->dev.of_node, "port-number", NULL);
+ if (prop)
+ id = be32_to_cpup(prop);
+#endif
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq <= 0)
+ return -ENXIO;
+
+ return ulite_assign(&pdev->dev, id, res->start, irq);
+}
+
+static int ulite_remove(struct platform_device *pdev)
+{
+ return ulite_release(&pdev->dev);
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:uartlite");
+
+static struct platform_driver ulite_platform_driver = {
+ .probe = ulite_probe,
+ .remove = ulite_remove,
+ .driver = {
+ .name = "uartlite",
+ .of_match_table = of_match_ptr(ulite_of_match),
+ },
+};
+
+/* ---------------------------------------------------------------------
+ * Module setup/teardown
+ */
+
+static int __init ulite_init(void)
+{
+ int ret;
+
+ pr_debug("uartlite: calling uart_register_driver()\n");
+ ret = uart_register_driver(&ulite_uart_driver);
+ if (ret)
+ goto err_uart;
+
+ pr_debug("uartlite: calling platform_driver_register()\n");
+ ret = platform_driver_register(&ulite_platform_driver);
+ if (ret)
+ goto err_plat;
+
+ return 0;
+
+err_plat:
+ uart_unregister_driver(&ulite_uart_driver);
+err_uart:
+ pr_err("registering uartlite driver failed: err=%i", ret);
+ return ret;
+}
+
+static void __exit ulite_exit(void)
+{
+ platform_driver_unregister(&ulite_platform_driver);
+ uart_unregister_driver(&ulite_uart_driver);
+}
+
+module_init(ulite_init);
+module_exit(ulite_exit);
+
+MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
+MODULE_DESCRIPTION("Xilinx uartlite serial driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff