diff options
Diffstat (limited to 'drivers/tty/serial/uartlite.c')
| -rw-r--r-- | drivers/tty/serial/uartlite.c | 942 |
1 files changed, 942 insertions, 0 deletions
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c new file mode 100644 index 0000000000..b225a78f61 --- /dev/null +++ b/drivers/tty/serial/uartlite.c @@ -0,0 +1,942 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * uartlite.c: Serial driver for Xilinx uartlite serial controller + * + * Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk> + * Copyright (C) 2007 Secret Lab Technologies Ltd. + */ + +#include <linux/platform_device.h> +#include <linux/module.h> +#include <linux/bitfield.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/iopoll.h> +#include <linux/of.h> +#include <linux/clk.h> +#include <linux/pm_runtime.h> + +#define ULITE_NAME "ttyUL" +#define ULITE_MAJOR 204 +#define ULITE_MINOR 187 +#define ULITE_NR_UARTS CONFIG_SERIAL_UARTLITE_NR_UARTS + +/* --------------------------------------------------------------------- + * Register definitions + * + * For register details see datasheet: + * https://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 +#define UART_AUTOSUSPEND_TIMEOUT 3000 /* ms */ + +/* Static pointer to console port */ +#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE +static struct uart_port *console_port; +#endif + +/** + * struct uartlite_data: Driver private data + * reg_ops: Functions to read/write registers + * clk: Our parent clock, if present + * baud: The baud rate configured when this device was synthesized + * cflags: The cflags for parity and data bits + */ +struct uartlite_data { + const struct uartlite_reg_ops *reg_ops; + struct clk *clk; + unsigned int baud; + tcflag_t cflags; +}; + +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 const 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 const 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_data *pdata = port->private_data; + + return pdata->reg_ops->in(port->membase + offset); +} + +static inline void uart_out32(u32 val, u32 offset, struct uart_port *port) +{ + struct uartlite_data *pdata = port->private_data; + + pdata->reg_ops->out(val, port->membase + offset); +} + +static struct uart_port ulite_ports[ULITE_NR_UARTS]; + +static struct uart_driver ulite_uart_driver; + +/* --------------------------------------------------------------------- + * 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); + uart_xmit_advance(port, 1); + + /* 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 stat, busy, n = 0; + unsigned long flags; + + do { + spin_lock_irqsave(&port->lock, flags); + stat = uart_in32(ULITE_STATUS, port); + busy = ulite_receive(port, stat); + busy |= ulite_transmit(port, stat); + spin_unlock_irqrestore(&port->lock, flags); + 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) +{ + struct uartlite_data *pdata = port->private_data; + int ret; + + ret = clk_enable(pdata->clk); + if (ret) { + dev_err(port->dev, "Failed to enable clock\n"); + return ret; + } + + ret = request_irq(port->irq, ulite_isr, IRQF_SHARED | IRQF_TRIGGER_RISING, + "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) +{ + struct uartlite_data *pdata = port->private_data; + + uart_out32(0, ULITE_CONTROL, port); + uart_in32(ULITE_CONTROL, port); /* dummy */ + free_irq(port->irq, port); + clk_disable(pdata->clk); +} + +static void ulite_set_termios(struct uart_port *port, + struct ktermios *termios, + const struct ktermios *old) +{ + unsigned long flags; + struct uartlite_data *pdata = port->private_data; + + /* Set termios to what the hardware supports */ + termios->c_iflag &= ~BRKINT; + termios->c_cflag &= ~(CSTOPB | PARENB | PARODD | CSIZE); + termios->c_cflag |= pdata->cflags & (PARENB | PARODD | CSIZE); + tty_termios_encode_baud_rate(termios, pdata->baud, pdata->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 */ + uart_update_timeout(port, termios->c_cflag, pdata->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) +{ + struct uartlite_data *pdata = port->private_data; + 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; + } + + pdata->reg_ops = &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) + pdata->reg_ops = &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; +} + +static void ulite_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + int ret; + + if (!state) { + ret = pm_runtime_get_sync(port->dev); + if (ret < 0) + dev_err(port->dev, "Failed to enable clocks\n"); + } else { + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); + } +} + +#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 const 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, + .pm = ulite_pm, +#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; + + /* + * Spin waiting for TX fifo to have space available. + * When using the Microblaze Debug Module this can take up to 1s + */ + if (read_poll_timeout_atomic(uart_in32, val, !(val & ULITE_STATUS_TXFULL), + 0, 1000000, false, ULITE_STATUS, port)) + dev_warn(port->dev, + "timeout waiting for TX buffer empty\n"); +} + +static void ulite_console_putchar(struct uart_port *port, unsigned char 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 = console_port; + 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 = NULL; + int baud = 9600; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (co->index >= 0 && co->index < ULITE_NR_UARTS) + port = ulite_ports + co->index; + + /* Has the device been initialized yet? */ + if (!port || !port->mapbase) { + pr_debug("console on ttyUL%i not present\n", co->index); + return -ENODEV; + } + + console_port = port; + + /* 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 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 void early_uartlite_putc(struct uart_port *port, unsigned char c) +{ + /* + * Limit how many times we'll spin waiting for TX FIFO status. + * This will prevent lockups if the base address is incorrectly + * set, or any other issue on the UARTLITE. + * This limit is pretty arbitrary, unless we are at about 10 baud + * we'll never timeout on a working UART. + */ + unsigned retries = 1000000; + + while (--retries && + (readl(port->membase + ULITE_STATUS) & ULITE_STATUS_TXFULL)) + ; + + /* Only attempt the iowrite if we didn't timeout */ + if (retries) + writel(c & 0xff, port->membase + ULITE_TX); +} + +static void early_uartlite_write(struct console *console, + const char *s, unsigned n) +{ + struct earlycon_device *device = console->data; + uart_console_write(&device->port, s, n, early_uartlite_putc); +} + +static int __init early_uartlite_setup(struct earlycon_device *device, + const char *options) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = early_uartlite_write; + return 0; +} +EARLYCON_DECLARE(uartlite, early_uartlite_setup); +OF_EARLYCON_DECLARE(uartlite_b, "xlnx,opb-uartlite-1.00.b", early_uartlite_setup); +OF_EARLYCON_DECLARE(uartlite_a, "xlnx,xps-uartlite-1.00.a", early_uartlite_setup); + +#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 + * @pdata: private data for uartlite + * + * Returns: 0 on success, <0 otherwise + */ +static int ulite_assign(struct device *dev, int id, phys_addr_t base, int irq, + struct uartlite_data *pdata) +{ + 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; + port->private_data = pdata; + + 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 void ulite_release(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + + if (port) { + uart_remove_one_port(&ulite_uart_driver, port); + dev_set_drvdata(dev, NULL); + port->mapbase = 0; + } +} + +/** + * ulite_suspend - Stop the device. + * + * @dev: handle to the device structure. + * Return: 0 always. + */ +static int __maybe_unused ulite_suspend(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + + if (port) + uart_suspend_port(&ulite_uart_driver, port); + + return 0; +} + +/** + * ulite_resume - Resume the device. + * + * @dev: handle to the device structure. + * Return: 0 on success, errno otherwise. + */ +static int __maybe_unused ulite_resume(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + + if (port) + uart_resume_port(&ulite_uart_driver, port); + + return 0; +} + +static int __maybe_unused ulite_runtime_suspend(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + struct uartlite_data *pdata = port->private_data; + + clk_disable(pdata->clk); + return 0; +}; + +static int __maybe_unused ulite_runtime_resume(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + struct uartlite_data *pdata = port->private_data; + int ret; + + ret = clk_enable(pdata->clk); + if (ret) { + dev_err(dev, "Cannot enable clock.\n"); + return ret; + } + return 0; +} + +/* --------------------------------------------------------------------- + * Platform bus binding + */ + +static const struct dev_pm_ops ulite_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(ulite_suspend, ulite_resume) + SET_RUNTIME_PM_OPS(ulite_runtime_suspend, + ulite_runtime_resume, NULL) +}; + +#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; + struct uartlite_data *pdata; + int irq, ret; + int id = pdev->id; + + pdata = devm_kzalloc(&pdev->dev, sizeof(struct uartlite_data), + GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + if (IS_ENABLED(CONFIG_OF)) { + const char *prop; + struct device_node *np = pdev->dev.of_node; + u32 val = 0; + + prop = "port-number"; + ret = of_property_read_u32(np, prop, &id); + if (ret && ret != -EINVAL) +of_err: + return dev_err_probe(&pdev->dev, ret, + "could not read %s\n", prop); + + prop = "current-speed"; + ret = of_property_read_u32(np, prop, &pdata->baud); + if (ret) + goto of_err; + + prop = "xlnx,use-parity"; + ret = of_property_read_u32(np, prop, &val); + if (ret && ret != -EINVAL) + goto of_err; + + if (val) { + prop = "xlnx,odd-parity"; + ret = of_property_read_u32(np, prop, &val); + if (ret) + goto of_err; + + if (val) + pdata->cflags |= PARODD; + pdata->cflags |= PARENB; + } + + val = 8; + prop = "xlnx,data-bits"; + ret = of_property_read_u32(np, prop, &val); + if (ret && ret != -EINVAL) + goto of_err; + + switch (val) { + case 5: + pdata->cflags |= CS5; + break; + case 6: + pdata->cflags |= CS6; + break; + case 7: + pdata->cflags |= CS7; + break; + case 8: + pdata->cflags |= CS8; + break; + default: + return dev_err_probe(&pdev->dev, -EINVAL, + "bad data bits %d\n", val); + } + } else { + pdata->baud = 9600; + pdata->cflags = CS8; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + pdata->clk = devm_clk_get(&pdev->dev, "s_axi_aclk"); + if (IS_ERR(pdata->clk)) { + if (PTR_ERR(pdata->clk) != -ENOENT) + return PTR_ERR(pdata->clk); + + /* + * Clock framework support is optional, continue on + * anyways if we don't find a matching clock. + */ + pdata->clk = NULL; + } + + ret = clk_prepare_enable(pdata->clk); + if (ret) { + dev_err(&pdev->dev, "Failed to prepare clock\n"); + return ret; + } + + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + if (!ulite_uart_driver.state) { + dev_dbg(&pdev->dev, "uartlite: calling uart_register_driver()\n"); + ret = uart_register_driver(&ulite_uart_driver); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to register driver\n"); + clk_disable_unprepare(pdata->clk); + return ret; + } + } + + ret = ulite_assign(&pdev->dev, id, res->start, irq, pdata); + + pm_runtime_mark_last_busy(&pdev->dev); + pm_runtime_put_autosuspend(&pdev->dev); + + return ret; +} + +static int ulite_remove(struct platform_device *pdev) +{ + struct uart_port *port = dev_get_drvdata(&pdev->dev); + struct uartlite_data *pdata = port->private_data; + + clk_disable_unprepare(pdata->clk); + ulite_release(&pdev->dev); + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); + pm_runtime_dont_use_autosuspend(&pdev->dev); + return 0; +} + +/* 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), + .pm = &ulite_pm_ops, + }, +}; + +/* --------------------------------------------------------------------- + * Module setup/teardown + */ + +static int __init ulite_init(void) +{ + + pr_debug("uartlite: calling platform_driver_register()\n"); + return platform_driver_register(&ulite_platform_driver); +} + +static void __exit ulite_exit(void) +{ + platform_driver_unregister(&ulite_platform_driver); + if (ulite_uart_driver.state) + 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"); |