atmel_serial: RS485 support Signed-off-by: Claudio Scordino Signed-off-by: Michael Trimarchi Signed-off-by: Rick Bronson Signed-off-by: Sebastian Heutling --- arch/arm/include/asm/ioctls.h | 2 + arch/arm/mach-at91/include/mach/board.h | 4 + drivers/serial/atmel_serial.c | 247 ++++++++++++++++++++++++++----- 3 files changed, 218 insertions(+), 35 deletions(-) diff --git a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h index a91d8a1..82f2177 100644 --- a/arch/arm/include/asm/ioctls.h +++ b/arch/arm/include/asm/ioctls.h @@ -70,6 +70,8 @@ #define TIOCGICOUNT 0x545D /* read serial port inline interrupt counts */ #define FIOQSIZE 0x545E +#define TIOCSRS485 0x5461 + /* Used for packet mode */ #define TIOCPKT_DATA 0 #define TIOCPKT_FLUSHREAD 1 diff --git a/arch/arm/mach-at91/include/mach/board.h b/arch/arm/mach-at91/include/mach/board.h index ceaec6c..21f1308 100644 --- a/arch/arm/mach-at91/include/mach/board.h +++ b/arch/arm/mach-at91/include/mach/board.h @@ -39,6 +39,7 @@ #include #include #include +#include /* USB Device */ struct at91_udc_data { @@ -146,6 +147,9 @@ struct atmel_uart_data { short use_dma_tx; /* use transmit DMA? */ short use_dma_rx; /* use receive DMA? */ void __iomem *regs; /* virtual base address, if any */ + struct serial_rs485 rs485; /* this flag specifies + if the uart must be used + as RS485 */ }; extern void __init at91_add_device_serial(void); diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c index 2c9bf9b..21bf3a8 100644 --- a/drivers/serial/atmel_serial.c +++ b/drivers/serial/atmel_serial.c @@ -38,6 +38,7 @@ #include #include #include +#include #include @@ -59,6 +60,9 @@ #include +static void atmel_start_rx(struct uart_port *port); +static void atmel_stop_rx(struct uart_port *port); + #ifdef CONFIG_SERIAL_ATMEL_TTYAT /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we @@ -93,6 +97,7 @@ #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR) #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR) #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR) +#define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR) /* PDC registers */ #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR) @@ -147,6 +152,16 @@ struct atmel_uart_port { unsigned int irq_status_prev; struct circ_buf rx_ring; + + struct serial_rs485 rs485; /* this flag specifies + if the uart must be used + as RS485 */ + /* Fields related to interrupts: + if (rs485) = ATMEL_US_TXEMPTY + else if (use_dma_tx) = ATMEL_US_ENDTX | ATMEL_US_TXBUFE + else = ATMEL_US_TXRDY; + */ + unsigned int tx_done_mask; }; static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART]; @@ -187,6 +202,85 @@ static bool atmel_use_dma_tx(struct uart_port *port) } #endif +/* Enable or disable the rs485 support */ +void atmel_enable_disable_rs485(struct uart_port *port, struct serial_rs485 *rs485conf) +{ + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + unsigned long flags; + unsigned int mode; + + spin_lock_irqsave(&port->lock, flags); + + mode = UART_GET_MR(port); + + /* Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; + + atmel_port->rs485 = *rs485conf; + + if (!(rs485conf->flags & SER_RS485_ENABLED)) { + dev_dbg(port->dev, "Setting UART to RS232\n"); + if (atmel_use_dma_tx(port)) + atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; + else + atmel_port->tx_done_mask = ATMEL_US_TXRDY; + } else { + dev_dbg(port->dev, "Setting UART to RS485\n"); + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; + UART_PUT_TTGR(port, rs485conf->delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; + } + UART_PUT_MR(port, mode); + + spin_unlock_irqrestore(&port->lock, flags); +} + + +static ssize_t show_rs485(struct device *dev, struct device_attribute *attr, \ + char *buf) +{ + struct platform_device *pdev = to_platform_device(dev); + struct uart_port *port = platform_get_drvdata(pdev); + unsigned int current_mode; + + current_mode = UART_GET_MR(port); + current_mode &= ATMEL_US_USMODE; + return snprintf(buf, PAGE_SIZE, "%u\n", current_mode); +} + +static ssize_t set_rs485(struct device *dev, struct device_attribute *attr, \ + const char *buf, size_t len) +{ + struct platform_device *pdev = to_platform_device(dev); + struct uart_port *port = platform_get_drvdata(pdev); + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + struct serial_rs485 rs485conf = atmel_port->rs485; + unsigned int value; + + if (buf == NULL) + goto err; + + value = simple_strtoul(buf, NULL, 10); + + if ((value != 0) && (value != 1)) + goto err; + + if (!value) { + rs485conf.flags &= ~(SER_RS485_ENABLED); + } else { + rs485conf.flags |= SER_RS485_ENABLED; + /* 0x4 is the normal reset value. */ + rs485conf.delay_rts_before_send = 0x00000004; + } + + atmel_enable_disable_rs485(port, &rs485conf); + +err: + return strnlen(buf, PAGE_SIZE); +} + +static DEVICE_ATTR(rs485, 0644, show_rs485, set_rs485); + /* * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty. */ @@ -202,6 +296,7 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) { unsigned int control = 0; unsigned int mode; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); #ifdef CONFIG_ARCH_AT91RM9200 if (cpu_is_at91rm9200()) { @@ -236,6 +331,16 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) mode |= ATMEL_US_CHMODE_LOC_LOOP; else mode |= ATMEL_US_CHMODE_NORMAL; + + /* Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; + + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { + dev_dbg(port->dev, "Keeping UART to RS485\n"); + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; + } else + dev_dbg(port->dev, "Keeping UART to RS232\n"); UART_PUT_MR(port, mode); } @@ -268,12 +373,17 @@ static u_int atmel_get_mctrl(struct uart_port *port) */ static void atmel_stop_tx(struct uart_port *port) { + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + if (atmel_use_dma_tx(port)) { /* disable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); - } else - UART_PUT_IDR(port, ATMEL_US_TXRDY); + } + /* Disable interrupts */ + UART_PUT_IDR(port, atmel_port->tx_done_mask); + + if (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_start_rx(port); } /* @@ -281,17 +391,22 @@ static void atmel_stop_tx(struct uart_port *port) */ static void atmel_start_tx(struct uart_port *port) { + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + if (atmel_use_dma_tx(port)) { if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN) /* The transmitter is already running. Yes, we really need this.*/ return; - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); + if (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_stop_rx(port); + /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - } else - UART_PUT_IER(port, ATMEL_US_TXRDY); + } + /* Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); } /* @@ -302,12 +417,28 @@ static void atmel_stop_rx(struct uart_port *port) if (atmel_use_dma_rx(port)) { /* disable PDC receive */ UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS); - UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); + UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | port->read_status_mask); } else UART_PUT_IDR(port, ATMEL_US_RXRDY); } /* + * start receiving - port is in process of being opened. + */ +static void atmel_start_rx(struct uart_port *port) +{ + UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */ + + if (atmel_use_dma_rx(port)) { + /* enable PDC controller */ + UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | port->read_status_mask); + UART_PUT_PTCR(port, ATMEL_PDC_RXTEN); + } else + UART_PUT_IER(port, ATMEL_US_RXRDY); +} + + +/* * Enable modem status interrupts */ static void atmel_enable_ms(struct uart_port *port) @@ -428,8 +559,9 @@ static void atmel_rx_chars(struct uart_port *port) static void atmel_tx_chars(struct uart_port *port) { struct circ_buf *xmit = &port->state->xmit; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - if (port->x_char && UART_GET_CSR(port) & ATMEL_US_TXRDY) { + if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) { UART_PUT_CHAR(port, port->x_char); port->icount.tx++; port->x_char = 0; @@ -437,7 +569,7 @@ static void atmel_tx_chars(struct uart_port *port) if (uart_circ_empty(xmit) || uart_tx_stopped(port)) return; - while (UART_GET_CSR(port) & ATMEL_US_TXRDY) { + while (UART_GET_CSR(port) & atmel_port->tx_done_mask) { UART_PUT_CHAR(port, xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; @@ -449,7 +581,8 @@ static void atmel_tx_chars(struct uart_port *port) uart_write_wakeup(port); if (!uart_circ_empty(xmit)) - UART_PUT_IER(port, ATMEL_US_TXRDY); + /* Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); } /* @@ -501,18 +634,10 @@ atmel_handle_transmit(struct uart_port *port, unsigned int pending) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - if (atmel_use_dma_tx(port)) { - /* PDC transmit */ - if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) { - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); - tasklet_schedule(&atmel_port->tasklet); - } - } else { - /* Interrupt transmit */ - if (pending & ATMEL_US_TXRDY) { - UART_PUT_IDR(port, ATMEL_US_TXRDY); - tasklet_schedule(&atmel_port->tasklet); - } + if (pending & atmel_port->tx_done_mask) { + /* Either PDC or interrupt transmission */ + UART_PUT_IDR(port, atmel_port->tx_done_mask); + tasklet_schedule(&atmel_port->tasklet); } } @@ -590,9 +715,15 @@ static void atmel_tx_dma(struct uart_port *port) UART_PUT_TPR(port, pdc->dma_addr + xmit->tail); UART_PUT_TCR(port, count); - /* re-enable PDC transmit and interrupts */ + /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); + /* Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); + } else { + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { + /* DMA done, stop TX, start RX for RS485 */ + atmel_start_rx(port); + } } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) @@ -1017,6 +1148,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, { unsigned long flags; unsigned int mode, imr, quot, baud; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); /* Get current mode register */ mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL @@ -1115,6 +1247,16 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, /* disable receiver and transmitter */ UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS); + /* Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; + + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { + dev_dbg(port->dev, "Keeping UART to RS485\n"); + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; + } else + dev_dbg(port->dev, "Keeping UART to RS232\n"); + /* set the parity, stop bits and data size */ UART_PUT_MR(port, mode); @@ -1231,6 +1373,31 @@ static void atmel_poll_put_char(struct uart_port *port, unsigned char ch) } #endif +static int atmel_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg) +{ + + switch (cmd) { + case TIOCSRS485: + { + struct serial_rs485 rs485conf; + if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg, + sizeof(rs485conf))) + return -EFAULT; + + dev_dbg(port->dev, "enable e/o disable rs485\n"); + + atmel_enable_disable_rs485(port, &rs485conf); + } + break; + + default: + return -ENOIOCTLCMD; + } + return 0; +} + + + static struct uart_ops atmel_pops = { .tx_empty = atmel_tx_empty, .set_mctrl = atmel_set_mctrl, @@ -1250,6 +1417,7 @@ static struct uart_ops atmel_pops = { .config_port = atmel_config_port, .verify_port = atmel_verify_port, .pm = atmel_serial_pm, + .ioctl = atmel_ioctl, #ifdef CONFIG_CONSOLE_POLL .poll_get_char = atmel_poll_get_char, .poll_put_char = atmel_poll_put_char, @@ -1265,13 +1433,12 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, struct uart_port *port = &atmel_port->uart; struct atmel_uart_data *data = pdev->dev.platform_data; - port->iotype = UPIO_MEM; - port->flags = UPF_BOOT_AUTOCONF; - port->ops = &atmel_pops; - port->fifosize = 1; - port->line = pdev->id; - port->dev = &pdev->dev; - + port->iotype = UPIO_MEM; + port->flags = UPF_BOOT_AUTOCONF; + port->ops = &atmel_pops; + port->fifosize = 1; + port->line = pdev->id; + port->dev = &pdev->dev; port->mapbase = pdev->resource[0].start; port->irq = pdev->resource[1].start; @@ -1299,8 +1466,15 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, atmel_port->use_dma_rx = data->use_dma_rx; atmel_port->use_dma_tx = data->use_dma_tx; - if (atmel_use_dma_tx(port)) + atmel_port->rs485 = data->rs485; + /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */ + if (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; + else if (atmel_use_dma_tx(port)) { port->fifosize = PDC_BUFFER_SIZE; + atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; + } else + atmel_port->tx_done_mask = ATMEL_US_TXRDY; } /* @@ -1334,6 +1508,7 @@ static void atmel_console_putchar(struct uart_port *port, int ch) static void atmel_console_write(struct console *co, const char *s, u_int count) { struct uart_port *port = &atmel_ports[co->index].uart; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int status, imr; unsigned int pdc_tx; @@ -1341,7 +1516,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) * First, save IMR and then disable interrupts */ imr = UART_GET_IMR(port); - UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY); + UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask); /* Store PDC transmit status and disable it */ pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN; @@ -1355,7 +1530,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) */ do { status = UART_GET_CSR(port); - } while (!(status & ATMEL_US_TXRDY)); + } while (!(status & atmel_port->tx_done_mask)); /* Restore PDC transmit status */ if (pdc_tx) @@ -1587,7 +1762,7 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev) device_init_wakeup(&pdev->dev, 1); platform_set_drvdata(pdev, port); - return 0; + return device_create_file(&(pdev->dev), &dev_attr_rs485); err_add_port: kfree(port->rx_ring.buf); @@ -1619,6 +1794,8 @@ static int __devexit atmel_serial_remove(struct platform_device *pdev) clk_put(atmel_port->clk); + device_remove_file(&(pdev->dev), &dev_attr_rs485); + return ret; } -- 1.6.0.4