#if defined(CONFIG_SERIAL_EFM32_UART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) #define SUPPORT_SYSRQ #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #define DRIVER_NAME "efm32-uart" #define DEV_NAME "ttyefm" #define UARTn_CTRL 0x00 #define UARTn_CTRL_SYNC 0x0001 #define UARTn_CTRL_TXBIL 0x1000 #define UARTn_FRAME 0x04 #define UARTn_FRAME_DATABITS__MASK 0x000f #define UARTn_FRAME_DATABITS(n) ((n) - 3) #define UARTn_FRAME_PARITY_NONE 0x0000 #define UARTn_FRAME_PARITY_EVEN 0x0200 #define UARTn_FRAME_PARITY_ODD 0x0300 #define UARTn_FRAME_STOPBITS_HALF 0x0000 #define UARTn_FRAME_STOPBITS_ONE 0x1000 #define UARTn_FRAME_STOPBITS_TWO 0x3000 #define UARTn_CMD 0x0c #define UARTn_CMD_RXEN 0x0001 #define UARTn_CMD_RXDIS 0x0002 #define UARTn_CMD_TXEN 0x0004 #define UARTn_CMD_TXDIS 0x0008 #define UARTn_STATUS 0x10 #define UARTn_STATUS_TXENS 0x0002 #define UARTn_STATUS_TXC 0x0020 #define UARTn_STATUS_TXBL 0x0040 #define UARTn_STATUS_RXDATAV 0x0080 #define UARTn_CLKDIV 0x14 #define UARTn_RXDATAX 0x18 #define UARTn_RXDATAX_RXDATA__MASK 0x01ff #define UARTn_RXDATAX_PERR 0x4000 #define UARTn_RXDATAX_FERR 0x8000 /* * This is a software only flag used for ignore_status_mask and * read_status_mask! It's used for breaks that the hardware doesn't report * explicitly. */ #define SW_UARTn_RXDATAX_BERR 0x2000 #define UARTn_TXDATA 0x34 #define UARTn_IF 0x40 #define UARTn_IF_TXC 0x0001 #define UARTn_IF_TXBL 0x0002 #define UARTn_IF_RXDATAV 0x0004 #define UARTn_IF_RXOF 0x0010 #define UARTn_IFS 0x44 #define UARTn_IFC 0x48 #define UARTn_IEN 0x4c #define UARTn_ROUTE 0x54 #define UARTn_ROUTE_LOCATION__MASK 0x0700 #define UARTn_ROUTE_LOCATION(n) (((n) << 8) & UARTn_ROUTE_LOCATION__MASK) #define UARTn_ROUTE_RXPEN 0x0001 #define UARTn_ROUTE_TXPEN 0x0002 struct efm32_uart_port { struct uart_port port; unsigned int txirq; struct clk *clk; struct efm32_uart_pdata pdata; }; #define to_efm_port(_port) container_of(_port, struct efm32_uart_port, port) #define efm_debug(efm_port, format, arg...) \ dev_dbg(efm_port->port.dev, format, ##arg) static void efm32_uart_write32(struct efm32_uart_port *efm_port, u32 value, unsigned offset) { writel_relaxed(value, efm_port->port.membase + offset); } static u32 efm32_uart_read32(struct efm32_uart_port *efm_port, unsigned offset) { return readl_relaxed(efm_port->port.membase + offset); } static unsigned int efm32_uart_tx_empty(struct uart_port *port) { struct efm32_uart_port *efm_port = to_efm_port(port); u32 status = efm32_uart_read32(efm_port, UARTn_STATUS); if (status & UARTn_STATUS_TXC) return TIOCSER_TEMT; else return 0; } static void efm32_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) { /* sorry, neither handshaking lines nor loop functionallity */ } static unsigned int efm32_uart_get_mctrl(struct uart_port *port) { /* sorry, no handshaking lines available */ return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR; } static void efm32_uart_stop_tx(struct uart_port *port) { struct efm32_uart_port *efm_port = to_efm_port(port); u32 ien = efm32_uart_read32(efm_port, UARTn_IEN); efm32_uart_write32(efm_port, UARTn_CMD_TXDIS, UARTn_CMD); ien &= ~(UARTn_IF_TXC | UARTn_IF_TXBL); efm32_uart_write32(efm_port, ien, UARTn_IEN); } static void efm32_uart_tx_chars(struct efm32_uart_port *efm_port) { struct uart_port *port = &efm_port->port; struct circ_buf *xmit = &port->state->xmit; while (efm32_uart_read32(efm_port, UARTn_STATUS) & UARTn_STATUS_TXBL) { if (port->x_char) { port->icount.tx++; efm32_uart_write32(efm_port, port->x_char, UARTn_TXDATA); port->x_char = 0; continue; } if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) { port->icount.tx++; efm32_uart_write32(efm_port, xmit->buf[xmit->tail], UARTn_TXDATA); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); } else break; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); if (!port->x_char && uart_circ_empty(xmit) && efm32_uart_read32(efm_port, UARTn_STATUS) & UARTn_STATUS_TXC) efm32_uart_stop_tx(port); } static void efm32_uart_start_tx(struct uart_port *port) { struct efm32_uart_port *efm_port = to_efm_port(port); u32 ien; efm32_uart_write32(efm_port, UARTn_IF_TXBL | UARTn_IF_TXC, UARTn_IFC); ien = efm32_uart_read32(efm_port, UARTn_IEN); efm32_uart_write32(efm_port, ien | UARTn_IF_TXBL | UARTn_IF_TXC, UARTn_IEN); efm32_uart_write32(efm_port, UARTn_CMD_TXEN, UARTn_CMD); efm32_uart_tx_chars(efm_port); } static void efm32_uart_stop_rx(struct uart_port *port) { struct efm32_uart_port *efm_port = to_efm_port(port); efm32_uart_write32(efm_port, UARTn_CMD_RXDIS, UARTn_CMD); } static void efm32_uart_enable_ms(struct uart_port *port) { /* no handshake lines, no modem status interrupts */ } static void efm32_uart_break_ctl(struct uart_port *port, int ctl) { /* not possible without fiddling with gpios */ } static void efm32_uart_rx_chars(struct efm32_uart_port *efm_port) { struct uart_port *port = &efm_port->port; while (efm32_uart_read32(efm_port, UARTn_STATUS) & UARTn_STATUS_RXDATAV) { u32 rxdata = efm32_uart_read32(efm_port, UARTn_RXDATAX); int flag = 0; /* * This is a reserved bit and I only saw it read as 0. But to be * sure not to be confused too much by new devices adhere to the * warning in the reference manual that reserverd bits might * read as 1 in the future. */ rxdata &= ~SW_UARTn_RXDATAX_BERR; port->icount.rx++; if ((rxdata & UARTn_RXDATAX_FERR) && !(rxdata & UARTn_RXDATAX_RXDATA__MASK)) { rxdata |= SW_UARTn_RXDATAX_BERR; port->icount.brk++; if (uart_handle_break(port)) continue; } else if (rxdata & UARTn_RXDATAX_PERR) port->icount.parity++; else if (rxdata & UARTn_RXDATAX_FERR) port->icount.frame++; rxdata &= port->read_status_mask; if (rxdata & SW_UARTn_RXDATAX_BERR) flag = TTY_BREAK; else if (rxdata & UARTn_RXDATAX_PERR) flag = TTY_PARITY; else if (rxdata & UARTn_RXDATAX_FERR) flag = TTY_FRAME; else if (uart_handle_sysrq_char(port, rxdata & UARTn_RXDATAX_RXDATA__MASK)) continue; if ((rxdata & port->ignore_status_mask) == 0) tty_insert_flip_char(&port->state->port, rxdata & UARTn_RXDATAX_RXDATA__MASK, flag); } } static irqreturn_t efm32_uart_rxirq(int irq, void *data) { struct efm32_uart_port *efm_port = data; u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF); int handled = IRQ_NONE; struct uart_port *port = &efm_port->port; struct tty_port *tport = &port->state->port; spin_lock(&port->lock); if (irqflag & UARTn_IF_RXDATAV) { efm32_uart_write32(efm_port, UARTn_IF_RXDATAV, UARTn_IFC); efm32_uart_rx_chars(efm_port); handled = IRQ_HANDLED; } if (irqflag & UARTn_IF_RXOF) { efm32_uart_write32(efm_port, UARTn_IF_RXOF, UARTn_IFC); port->icount.overrun++; tty_insert_flip_char(tport, 0, TTY_OVERRUN); handled = IRQ_HANDLED; } tty_flip_buffer_push(tport); spin_unlock(&port->lock); return handled; } static irqreturn_t efm32_uart_txirq(int irq, void *data) { struct efm32_uart_port *efm_port = data; u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF); /* TXBL doesn't need to be cleared */ if (irqflag & UARTn_IF_TXC) efm32_uart_write32(efm_port, UARTn_IF_TXC, UARTn_IFC); if (irqflag & (UARTn_IF_TXC | UARTn_IF_TXBL)) { efm32_uart_tx_chars(efm_port); return IRQ_HANDLED; } else return IRQ_NONE; } static int efm32_uart_startup(struct uart_port *port) { struct efm32_uart_port *efm_port = to_efm_port(port); int ret; ret = clk_enable(efm_port->clk); if (ret) { efm_debug(efm_port, "failed to enable clk\n"); goto err_clk_enable; } port->uartclk = clk_get_rate(efm_port->clk); /* Enable pins at configured location */ efm32_uart_write32(efm_port, UARTn_ROUTE_LOCATION(efm_port->pdata.location) | UARTn_ROUTE_RXPEN | UARTn_ROUTE_TXPEN, UARTn_ROUTE); ret = request_irq(port->irq, efm32_uart_rxirq, 0, DRIVER_NAME, efm_port); if (ret) { efm_debug(efm_port, "failed to register rxirq\n"); goto err_request_irq_rx; } /* disable all irqs */ efm32_uart_write32(efm_port, 0, UARTn_IEN); ret = request_irq(efm_port->txirq, efm32_uart_txirq, 0, DRIVER_NAME, efm_port); if (ret) { efm_debug(efm_port, "failed to register txirq\n"); free_irq(port->irq, efm_port); err_request_irq_rx: clk_disable(efm_port->clk); } else { efm32_uart_write32(efm_port, UARTn_IF_RXDATAV | UARTn_IF_RXOF, UARTn_IEN); efm32_uart_write32(efm_port, UARTn_CMD_RXEN, UARTn_CMD); } err_clk_enable: return ret; } static void efm32_uart_shutdown(struct uart_port *port) { struct efm32_uart_port *efm_port = to_efm_port(port); efm32_uart_write32(efm_port, 0, UARTn_IEN); free_irq(port->irq, efm_port); clk_disable(efm_port->clk); } static void efm32_uart_set_termios(struct uart_port *port, struct ktermios *new, struct ktermios *old) { struct efm32_uart_port *efm_port = to_efm_port(port); unsigned long flags; unsigned baud; u32 clkdiv; u32 frame = 0; /* no modem control lines */ new->c_cflag &= ~(CRTSCTS | CMSPAR); baud = uart_get_baud_rate(port, new, old, DIV_ROUND_CLOSEST(port->uartclk, 16 * 8192), DIV_ROUND_CLOSEST(port->uartclk, 16)); switch (new->c_cflag & CSIZE) { case CS5: frame |= UARTn_FRAME_DATABITS(5); break; case CS6: frame |= UARTn_FRAME_DATABITS(6); break; case CS7: frame |= UARTn_FRAME_DATABITS(7); break; case CS8: frame |= UARTn_FRAME_DATABITS(8); break; } if (new->c_cflag & CSTOPB) /* the receiver only verifies the first stop bit */ frame |= UARTn_FRAME_STOPBITS_TWO; else frame |= UARTn_FRAME_STOPBITS_ONE; if (new->c_cflag & PARENB) { if (new->c_cflag & PARODD) frame |= UARTn_FRAME_PARITY_ODD; else frame |= UARTn_FRAME_PARITY_EVEN; } else frame |= UARTn_FRAME_PARITY_NONE; /* * the 6 lowest bits of CLKDIV are dc, bit 6 has value 0.25. * port->uartclk <= 14e6, so 4 * port->uartclk doesn't overflow. */ clkdiv = (DIV_ROUND_CLOSEST(4 * port->uartclk, 16 * baud) - 4) << 6; spin_lock_irqsave(&port->lock, flags); efm32_uart_write32(efm_port, UARTn_CMD_TXDIS | UARTn_CMD_RXDIS, UARTn_CMD); port->read_status_mask = UARTn_RXDATAX_RXDATA__MASK; if (new->c_iflag & INPCK) port->read_status_mask |= UARTn_RXDATAX_FERR | UARTn_RXDATAX_PERR; if (new->c_iflag & (BRKINT | PARMRK)) port->read_status_mask |= SW_UARTn_RXDATAX_BERR; port->ignore_status_mask = 0; if (new->c_iflag & IGNPAR) port->ignore_status_mask |= UARTn_RXDATAX_FERR | UARTn_RXDATAX_PERR; if (new->c_iflag & IGNBRK) port->ignore_status_mask |= SW_UARTn_RXDATAX_BERR; uart_update_timeout(port, new->c_cflag, baud); efm32_uart_write32(efm_port, UARTn_CTRL_TXBIL, UARTn_CTRL); efm32_uart_write32(efm_port, frame, UARTn_FRAME); efm32_uart_write32(efm_port, clkdiv, UARTn_CLKDIV); efm32_uart_write32(efm_port, UARTn_CMD_TXEN | UARTn_CMD_RXEN, UARTn_CMD); spin_unlock_irqrestore(&port->lock, flags); } static const char *efm32_uart_type(struct uart_port *port) { return port->type == PORT_EFMUART ? "efm32-uart" : NULL; } static void efm32_uart_release_port(struct uart_port *port) { struct efm32_uart_port *efm_port = to_efm_port(port); clk_unprepare(efm_port->clk); clk_put(efm_port->clk); iounmap(port->membase); } static int efm32_uart_request_port(struct uart_port *port) { struct efm32_uart_port *efm_port = to_efm_port(port); int ret; port->membase = ioremap(port->mapbase, 60); if (!efm_port->port.membase) { ret = -ENOMEM; efm_debug(efm_port, "failed to remap\n"); goto err_ioremap; } efm_port->clk = clk_get(port->dev, NULL); if (IS_ERR(efm_port->clk)) { ret = PTR_ERR(efm_port->clk); efm_debug(efm_port, "failed to get clock\n"); goto err_clk_get; } ret = clk_prepare(efm_port->clk); if (ret) { clk_put(efm_port->clk); err_clk_get: iounmap(port->membase); err_ioremap: return ret; } return 0; } static void efm32_uart_config_port(struct uart_port *port, int type) { if (type & UART_CONFIG_TYPE && !efm32_uart_request_port(port)) port->type = PORT_EFMUART; } static int efm32_uart_verify_port(struct uart_port *port, struct serial_struct *serinfo) { int ret = 0; if (serinfo->type != PORT_UNKNOWN && serinfo->type != PORT_EFMUART) ret = -EINVAL; return ret; } static struct uart_ops efm32_uart_pops = { .tx_empty = efm32_uart_tx_empty, .set_mctrl = efm32_uart_set_mctrl, .get_mctrl = efm32_uart_get_mctrl, .stop_tx = efm32_uart_stop_tx, .start_tx = efm32_uart_start_tx, .stop_rx = efm32_uart_stop_rx, .enable_ms = efm32_uart_enable_ms, .break_ctl = efm32_uart_break_ctl, .startup = efm32_uart_startup, .shutdown = efm32_uart_shutdown, .set_termios = efm32_uart_set_termios, .type = efm32_uart_type, .release_port = efm32_uart_release_port, .request_port = efm32_uart_request_port, .config_port = efm32_uart_config_port, .verify_port = efm32_uart_verify_port, }; static struct efm32_uart_port *efm32_uart_ports[5]; #ifdef CONFIG_SERIAL_EFM32_UART_CONSOLE static void efm32_uart_console_putchar(struct uart_port *port, int ch) { struct efm32_uart_port *efm_port = to_efm_port(port); unsigned int timeout = 0x400; u32 status; while (1) { status = efm32_uart_read32(efm_port, UARTn_STATUS); if (status & UARTn_STATUS_TXBL) break; if (!timeout--) return; } efm32_uart_write32(efm_port, ch, UARTn_TXDATA); } static void efm32_uart_console_write(struct console *co, const char *s, unsigned int count) { struct efm32_uart_port *efm_port = efm32_uart_ports[co->index]; u32 status = efm32_uart_read32(efm_port, UARTn_STATUS); unsigned int timeout = 0x400; if (!(status & UARTn_STATUS_TXENS)) efm32_uart_write32(efm_port, UARTn_CMD_TXEN, UARTn_CMD); uart_console_write(&efm_port->port, s, count, efm32_uart_console_putchar); /* Wait for the transmitter to become empty */ while (1) { u32 status = efm32_uart_read32(efm_port, UARTn_STATUS); if (status & UARTn_STATUS_TXC) break; if (!timeout--) break; } if (!(status & UARTn_STATUS_TXENS)) efm32_uart_write32(efm_port, UARTn_CMD_TXDIS, UARTn_CMD); } static void efm32_uart_console_get_options(struct efm32_uart_port *efm_port, int *baud, int *parity, int *bits) { u32 ctrl = efm32_uart_read32(efm_port, UARTn_CTRL); u32 route, clkdiv, frame; if (ctrl & UARTn_CTRL_SYNC) /* not operating in async mode */ return; route = efm32_uart_read32(efm_port, UARTn_ROUTE); if (!(route & UARTn_ROUTE_TXPEN)) /* tx pin not routed */ return; clkdiv = efm32_uart_read32(efm_port, UARTn_CLKDIV); *baud = DIV_ROUND_CLOSEST(4 * efm_port->port.uartclk, 16 * (4 + (clkdiv >> 6))); frame = efm32_uart_read32(efm_port, UARTn_FRAME); if (frame & UARTn_FRAME_PARITY_ODD) *parity = 'o'; else if (frame & UARTn_FRAME_PARITY_EVEN) *parity = 'e'; else *parity = 'n'; *bits = (frame & UARTn_FRAME_DATABITS__MASK) - UARTn_FRAME_DATABITS(4) + 4; efm_debug(efm_port, "get_opts: options=%d%c%d\n", *baud, *parity, *bits); } static int efm32_uart_console_setup(struct console *co, char *options) { struct efm32_uart_port *efm_port; int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; int ret; if (co->index < 0 || co->index >= ARRAY_SIZE(efm32_uart_ports)) { unsigned i; for (i = 0; i < ARRAY_SIZE(efm32_uart_ports); ++i) { if (efm32_uart_ports[i]) { pr_warn("efm32-console: fall back to console index %u (from %hhi)\n", i, co->index); co->index = i; break; } } } efm_port = efm32_uart_ports[co->index]; if (!efm_port) { pr_warn("efm32-console: No port at %d\n", co->index); return -ENODEV; } ret = clk_prepare(efm_port->clk); if (ret) { dev_warn(efm_port->port.dev, "console: clk_prepare failed: %d\n", ret); return ret; } efm_port->port.uartclk = clk_get_rate(efm_port->clk); if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else efm32_uart_console_get_options(efm_port, &baud, &parity, &bits); return uart_set_options(&efm_port->port, co, baud, parity, bits, flow); } static struct uart_driver efm32_uart_reg; static struct console efm32_uart_console = { .name = DEV_NAME, .write = efm32_uart_console_write, .device = uart_console_device, .setup = efm32_uart_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &efm32_uart_reg, }; #else #define efm32_uart_console (*(struct console *)NULL) #endif /* ifdef CONFIG_SERIAL_EFM32_UART_CONSOLE / else */ static struct uart_driver efm32_uart_reg = { .owner = THIS_MODULE, .driver_name = DRIVER_NAME, .dev_name = DEV_NAME, .nr = ARRAY_SIZE(efm32_uart_ports), .cons = &efm32_uart_console, }; static int efm32_uart_probe_dt(struct platform_device *pdev, struct efm32_uart_port *efm_port) { struct device_node *np = pdev->dev.of_node; u32 location; int ret; if (!np) return 1; ret = of_property_read_u32(np, "location", &location); if (!ret) { if (location > 5) { dev_err(&pdev->dev, "invalid location\n"); return -EINVAL; } efm_debug(efm_port, "using location %u\n", location); efm_port->pdata.location = location; } else { efm_debug(efm_port, "fall back to location 0\n"); } ret = of_alias_get_id(np, "serial"); if (ret < 0) { dev_err(&pdev->dev, "failed to get alias id: %d\n", ret); return ret; } else { efm_port->port.line = ret; return 0; } } static int efm32_uart_probe(struct platform_device *pdev) { struct efm32_uart_port *efm_port; struct resource *res; int ret; efm_port = kzalloc(sizeof(*efm_port), GFP_KERNEL); if (!efm_port) { dev_dbg(&pdev->dev, "failed to allocate private data\n"); return -ENOMEM; } res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { ret = -ENODEV; dev_dbg(&pdev->dev, "failed to determine base address\n"); goto err_get_base; } if (resource_size(res) < 60) { ret = -EINVAL; dev_dbg(&pdev->dev, "memory resource too small\n"); goto err_too_small; } ret = platform_get_irq(pdev, 0); if (ret <= 0) { dev_dbg(&pdev->dev, "failed to get rx irq\n"); goto err_get_rxirq; } efm_port->port.irq = ret; ret = platform_get_irq(pdev, 1); if (ret <= 0) ret = efm_port->port.irq + 1; efm_port->txirq = ret; efm_port->port.dev = &pdev->dev; efm_port->port.mapbase = res->start; efm_port->port.type = PORT_EFMUART; efm_port->port.iotype = UPIO_MEM32; efm_port->port.fifosize = 2; efm_port->port.ops = &efm32_uart_pops; efm_port->port.flags = UPF_BOOT_AUTOCONF; ret = efm32_uart_probe_dt(pdev, efm_port); if (ret > 0) { /* not created by device tree */ const struct efm32_uart_pdata *pdata = dev_get_platdata(&pdev->dev); efm_port->port.line = pdev->id; if (pdata) efm_port->pdata = *pdata; } if (efm_port->port.line >= 0 && efm_port->port.line < ARRAY_SIZE(efm32_uart_ports)) efm32_uart_ports[efm_port->port.line] = efm_port; ret = uart_add_one_port(&efm32_uart_reg, &efm_port->port); if (ret) { dev_dbg(&pdev->dev, "failed to add port: %d\n", ret); if (pdev->id >= 0 && pdev->id < ARRAY_SIZE(efm32_uart_ports)) efm32_uart_ports[pdev->id] = NULL; err_get_rxirq: err_too_small: err_get_base: kfree(efm_port); } else { platform_set_drvdata(pdev, efm_port); dev_dbg(&pdev->dev, "\\o/\n"); } return ret; } static int efm32_uart_remove(struct platform_device *pdev) { struct efm32_uart_port *efm_port = platform_get_drvdata(pdev); platform_set_drvdata(pdev, NULL); uart_remove_one_port(&efm32_uart_reg, &efm_port->port); if (pdev->id >= 0 && pdev->id < ARRAY_SIZE(efm32_uart_ports)) efm32_uart_ports[pdev->id] = NULL; kfree(efm_port); return 0; } static struct of_device_id efm32_uart_dt_ids[] = { { .compatible = "efm32,uart", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, efm32_uart_dt_ids); static struct platform_driver efm32_uart_driver = { .probe = efm32_uart_probe, .remove = efm32_uart_remove, .driver = { .name = DRIVER_NAME, .owner = THIS_MODULE, .of_match_table = efm32_uart_dt_ids, }, }; static int __init efm32_uart_init(void) { int ret; ret = uart_register_driver(&efm32_uart_reg); if (ret) return ret; ret = platform_driver_register(&efm32_uart_driver); if (ret) uart_unregister_driver(&efm32_uart_reg); pr_info("EFM32 UART/USART driver\n"); return ret; } module_init(efm32_uart_init); static void __exit efm32_uart_exit(void) { platform_driver_unregister(&efm32_uart_driver); uart_unregister_driver(&efm32_uart_reg); } MODULE_AUTHOR("Uwe Kleine-Koenig "); MODULE_DESCRIPTION("EFM32 UART/USART driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:" DRIVER_NAME);