diff options
Diffstat (limited to 'drivers/tty/serial/xilinx_uartps.c')
| -rw-r--r-- | drivers/tty/serial/xilinx_uartps.c | 304 |
1 files changed, 209 insertions, 95 deletions
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 9ca1a4d1b66a..f37edaa5ac75 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -57,7 +57,7 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255"); #define CDNS_UART_IMR 0x10 /* Interrupt Mask */ #define CDNS_UART_ISR 0x14 /* Interrupt Status */ #define CDNS_UART_BAUDGEN 0x18 /* Baud Rate Generator */ -#define CDNS_UART_RXTOUT 0x1C /* RX Timeout */ +#define CDNS_UART_RXTOUT 0x1C /* RX Timeout */ #define CDNS_UART_RXWM 0x20 /* RX FIFO Trigger Level */ #define CDNS_UART_MODEMCR 0x24 /* Modem Control */ #define CDNS_UART_MODEMSR 0x28 /* Modem Status */ @@ -68,6 +68,7 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255"); #define CDNS_UART_IRRX_PWIDTH 0x3C /* IR Min Received Pulse Width */ #define CDNS_UART_IRTX_PWIDTH 0x40 /* IR Transmitted pulse Width */ #define CDNS_UART_TXWM 0x44 /* TX FIFO Trigger Level */ +#define CDNS_UART_RXBS 0x48 /* RX FIFO byte status register */ /* Control Register Bit Definitions */ #define CDNS_UART_CR_STOPBRK 0x00000100 /* Stop TX break */ @@ -79,6 +80,9 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255"); #define CDNS_UART_CR_TXRST 0x00000002 /* TX logic reset */ #define CDNS_UART_CR_RXRST 0x00000001 /* RX logic reset */ #define CDNS_UART_CR_RST_TO 0x00000040 /* Restart Timeout Counter */ +#define CDNS_UART_RXBS_PARITY 0x00000001 /* Parity error status */ +#define CDNS_UART_RXBS_FRAMING 0x00000002 /* Framing error status */ +#define CDNS_UART_RXBS_BRK 0x00000004 /* Overrun error status */ /* * Mode Register: @@ -126,13 +130,27 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255"); #define CDNS_UART_IXR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt. */ #define CDNS_UART_IXR_MASK 0x00001FFF /* Valid bit mask */ -#define CDNS_UART_RX_IRQS (CDNS_UART_IXR_PARITY | CDNS_UART_IXR_FRAMING | \ - CDNS_UART_IXR_OVERRUN | CDNS_UART_IXR_RXTRIG | \ + /* + * Do not enable parity error interrupt for the following + * reason: When parity error interrupt is enabled, each Rx + * parity error always results in 2 events. The first one + * being parity error interrupt and the second one with a + * proper Rx interrupt with the incoming data. Disabling + * parity error interrupt ensures better handling of parity + * error events. With this change, for a parity error case, we + * get a Rx interrupt with parity error set in ISR register + * and we still handle parity errors in the desired way. + */ + +#define CDNS_UART_RX_IRQS (CDNS_UART_IXR_FRAMING | \ + CDNS_UART_IXR_OVERRUN | \ + CDNS_UART_IXR_RXTRIG | \ CDNS_UART_IXR_TOUT) /* Goes in read_status_mask for break detection as the HW doesn't do it*/ -#define CDNS_UART_IXR_BRK 0x80000000 +#define CDNS_UART_IXR_BRK 0x00002000 +#define CDNS_UART_RXBS_SUPPORT BIT(1) /* * Modem Control register: * The read/write Modem Control register controls the interface with the modem @@ -172,46 +190,66 @@ struct cdns_uart { struct clk *pclk; unsigned int baud; struct notifier_block clk_rate_change_nb; + u32 quirks; +}; +struct cdns_platform_data { + u32 quirks; }; #define to_cdns_uart(_nb) container_of(_nb, struct cdns_uart, \ clk_rate_change_nb); -static void cdns_uart_handle_rx(struct uart_port *port, unsigned int isrstatus) +/** + * cdns_uart_handle_rx - Handle the received bytes along with Rx errors. + * @dev_id: Id of the UART port + * @isrstatus: The interrupt status register value as read + * Return: None + */ +static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus) { - /* - * There is no hardware break detection, so we interpret framing - * error with all-zeros data as a break sequence. Most of the time, - * there's another non-zero byte at the end of the sequence. - */ - if (isrstatus & CDNS_UART_IXR_FRAMING) { - while (!(readl(port->membase + CDNS_UART_SR) & - CDNS_UART_SR_RXEMPTY)) { - if (!readl(port->membase + CDNS_UART_FIFO)) { + struct uart_port *port = (struct uart_port *)dev_id; + struct cdns_uart *cdns_uart = port->private_data; + unsigned int data; + unsigned int rxbs_status = 0; + unsigned int status_mask; + unsigned int framerrprocessed = 0; + char status = TTY_NORMAL; + bool is_rxbs_support; + + is_rxbs_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT; + + while ((readl(port->membase + CDNS_UART_SR) & + CDNS_UART_SR_RXEMPTY) != CDNS_UART_SR_RXEMPTY) { + if (is_rxbs_support) + rxbs_status = readl(port->membase + CDNS_UART_RXBS); + data = readl(port->membase + CDNS_UART_FIFO); + port->icount.rx++; + /* + * There is no hardware break detection in Zynq, so we interpret + * framing error with all-zeros data as a break sequence. + * Most of the time, there's another non-zero byte at the + * end of the sequence. + */ + if (!is_rxbs_support && (isrstatus & CDNS_UART_IXR_FRAMING)) { + if (!data) { port->read_status_mask |= CDNS_UART_IXR_BRK; - isrstatus &= ~CDNS_UART_IXR_FRAMING; + framerrprocessed = 1; + continue; } } - writel(CDNS_UART_IXR_FRAMING, port->membase + CDNS_UART_ISR); - } - - /* drop byte with parity error if IGNPAR specified */ - if (isrstatus & port->ignore_status_mask & CDNS_UART_IXR_PARITY) - isrstatus &= ~(CDNS_UART_IXR_RXTRIG | CDNS_UART_IXR_TOUT); - - isrstatus &= port->read_status_mask; - isrstatus &= ~port->ignore_status_mask; - - if (!(isrstatus & (CDNS_UART_IXR_TOUT | CDNS_UART_IXR_RXTRIG))) - return; - - while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_RXEMPTY)) { - u32 data; - char status = TTY_NORMAL; + if (is_rxbs_support && (rxbs_status & CDNS_UART_RXBS_BRK)) { + port->icount.brk++; + status = TTY_BREAK; + if (uart_handle_break(port)) + continue; + } - data = readl(port->membase + CDNS_UART_FIFO); + isrstatus &= port->read_status_mask; + isrstatus &= ~port->ignore_status_mask; + status_mask = port->read_status_mask; + status_mask &= ~port->ignore_status_mask; - /* Non-NULL byte after BREAK is garbage (99%) */ - if (data && (port->read_status_mask & CDNS_UART_IXR_BRK)) { + if (data && + (port->read_status_mask & CDNS_UART_IXR_BRK)) { port->read_status_mask &= ~CDNS_UART_IXR_BRK; port->icount.brk++; if (uart_handle_break(port)) @@ -221,57 +259,83 @@ static void cdns_uart_handle_rx(struct uart_port *port, unsigned int isrstatus) if (uart_handle_sysrq_char(port, data)) continue; - port->icount.rx++; - - if (isrstatus & CDNS_UART_IXR_PARITY) { - port->icount.parity++; - status = TTY_PARITY; - } else if (isrstatus & CDNS_UART_IXR_FRAMING) { - port->icount.frame++; - status = TTY_FRAME; - } else if (isrstatus & CDNS_UART_IXR_OVERRUN) { + if (is_rxbs_support) { + if ((rxbs_status & CDNS_UART_RXBS_PARITY) + && (status_mask & CDNS_UART_IXR_PARITY)) { + port->icount.parity++; + status = TTY_PARITY; + } + if ((rxbs_status & CDNS_UART_RXBS_FRAMING) + && (status_mask & CDNS_UART_IXR_PARITY)) { + port->icount.frame++; + status = TTY_FRAME; + } + } else { + if (isrstatus & CDNS_UART_IXR_PARITY) { + port->icount.parity++; + status = TTY_PARITY; + } + if ((isrstatus & CDNS_UART_IXR_FRAMING) && + !framerrprocessed) { + port->icount.frame++; + status = TTY_FRAME; + } + } + if (isrstatus & CDNS_UART_IXR_OVERRUN) { port->icount.overrun++; + tty_insert_flip_char(&port->state->port, 0, + TTY_OVERRUN); } - - uart_insert_char(port, isrstatus, CDNS_UART_IXR_OVERRUN, - data, status); + tty_insert_flip_char(&port->state->port, data, status); + isrstatus = 0; } + spin_unlock(&port->lock); tty_flip_buffer_push(&port->state->port); + spin_lock(&port->lock); } -static void cdns_uart_handle_tx(struct uart_port *port) +/** + * cdns_uart_handle_tx - Handle the bytes to be Txed. + * @dev_id: Id of the UART port + * Return: None + */ +static void cdns_uart_handle_tx(void *dev_id) { + struct uart_port *port = (struct uart_port *)dev_id; unsigned int numbytes; if (uart_circ_empty(&port->state->xmit)) { writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR); - return; - } - - numbytes = port->fifosize; - while (numbytes && !uart_circ_empty(&port->state->xmit) && - !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)) { - /* - * Get the data from the UART circular buffer - * and write it to the cdns_uart's TX_FIFO - * register. - */ - writel(port->state->xmit.buf[port->state->xmit.tail], - port->membase + CDNS_UART_FIFO); - port->icount.tx++; - - /* - * Adjust the tail of the UART buffer and wrap - * the buffer if it reaches limit. - */ - port->state->xmit.tail = - (port->state->xmit.tail + 1) & (UART_XMIT_SIZE - 1); + } else { + numbytes = port->fifosize; + while (numbytes && !uart_circ_empty(&port->state->xmit) && + !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)) { + /* + * Get the data from the UART circular buffer + * and write it to the cdns_uart's TX_FIFO + * register. + */ + writel( + port->state->xmit.buf[port->state->xmit. + tail], port->membase + CDNS_UART_FIFO); + + port->icount.tx++; + + /* + * Adjust the tail of the UART buffer and wrap + * the buffer if it reaches limit. + */ + port->state->xmit.tail = + (port->state->xmit.tail + 1) & + (UART_XMIT_SIZE - 1); + + numbytes--; + } - numbytes--; + if (uart_circ_chars_pending( + &port->state->xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); } - - if (uart_circ_chars_pending(&port->state->xmit) < WAKEUP_CHARS) - uart_write_wakeup(port); } /** @@ -284,27 +348,24 @@ static void cdns_uart_handle_tx(struct uart_port *port) static irqreturn_t cdns_uart_isr(int irq, void *dev_id) { struct uart_port *port = (struct uart_port *)dev_id; - unsigned long flags; unsigned int isrstatus; - spin_lock_irqsave(&port->lock, flags); + spin_lock(&port->lock); /* Read the interrupt status register to determine which - * interrupt(s) is/are active. + * interrupt(s) is/are active and clear them. */ isrstatus = readl(port->membase + CDNS_UART_ISR); - - if (isrstatus & CDNS_UART_RX_IRQS) - cdns_uart_handle_rx(port, isrstatus); - - if ((isrstatus & CDNS_UART_IXR_TXEMPTY) == CDNS_UART_IXR_TXEMPTY) - cdns_uart_handle_tx(port); - writel(isrstatus, port->membase + CDNS_UART_ISR); - /* be sure to release the lock and tty before leaving */ - spin_unlock_irqrestore(&port->lock, flags); + if (isrstatus & CDNS_UART_IXR_TXEMPTY) { + cdns_uart_handle_tx(dev_id); + isrstatus &= ~CDNS_UART_IXR_TXEMPTY; + } + if (isrstatus & CDNS_UART_IXR_MASK) + cdns_uart_handle_rx(dev_id, isrstatus); + spin_unlock(&port->lock); return IRQ_HANDLED; } @@ -653,6 +714,10 @@ static void cdns_uart_set_termios(struct uart_port *port, ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST; writel(ctrl_reg, port->membase + CDNS_UART_CR); + while (readl(port->membase + CDNS_UART_CR) & + (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST)) + cpu_relax(); + /* * Clear the RX disable and TX disable bits and then set the TX enable * bit and RX enable bit to enable the transmitter and receiver. @@ -736,10 +801,14 @@ static void cdns_uart_set_termios(struct uart_port *port, */ static int cdns_uart_startup(struct uart_port *port) { + struct cdns_uart *cdns_uart = port->private_data; + bool is_brk_support; int ret; unsigned long flags; unsigned int status = 0; + is_brk_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT; + spin_lock_irqsave(&port->lock, flags); /* Disable the TX and RX */ @@ -752,6 +821,10 @@ static int cdns_uart_startup(struct uart_port *port) writel(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST, port->membase + CDNS_UART_CR); + while (readl(port->membase + CDNS_UART_CR) & + (CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST)) + cpu_relax(); + /* * Clear the RX disable bit and then set the RX enable bit to enable * the receiver. @@ -794,7 +867,11 @@ static int cdns_uart_startup(struct uart_port *port) } /* Set the Interrupt Registers with desired interrupts */ - writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IER); + if (is_brk_support) + writel(CDNS_UART_RX_IRQS | CDNS_UART_IXR_BRK, + port->membase + CDNS_UART_IER); + else + writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IER); return 0; } @@ -993,7 +1070,7 @@ static void cdns_uart_pm(struct uart_port *port, unsigned int state, } } -static struct uart_ops cdns_uart_ops = { +static const struct uart_ops cdns_uart_ops = { .set_mctrl = cdns_uart_set_mctrl, .get_mctrl = cdns_uart_get_mctrl, .start_tx = cdns_uart_start_tx, @@ -1088,9 +1165,34 @@ static void __init cdns_early_write(struct console *con, const char *s, static int __init cdns_early_console_setup(struct earlycon_device *device, const char *opt) { - if (!device->port.membase) + struct uart_port *port = &device->port; + + if (!port->membase) return -ENODEV; + /* initialise control register */ + writel(CDNS_UART_CR_TX_EN|CDNS_UART_CR_TXRST|CDNS_UART_CR_RXRST, + port->membase + CDNS_UART_CR); + + /* only set baud if specified on command line - otherwise + * assume it has been initialized by a boot loader. + */ + if (device->baud) { + u32 cd = 0, bdiv = 0; + u32 mr; + int div8; + + cdns_uart_calc_baud_divs(port->uartclk, device->baud, + &bdiv, &cd, &div8); + mr = CDNS_UART_MR_PARITY_NONE; + if (div8) + mr |= CDNS_UART_MR_CLKSEL; + + writel(mr, port->membase + CDNS_UART_MR); + writel(cd, port->membase + CDNS_UART_BAUDGEN); + writel(bdiv, port->membase + CDNS_UART_BAUDDIV); + } + device->con->write = cdns_early_write; return 0; @@ -1328,6 +1430,18 @@ static int cdns_uart_resume(struct device *device) static SIMPLE_DEV_PM_OPS(cdns_uart_dev_pm_ops, cdns_uart_suspend, cdns_uart_resume); +static const struct cdns_platform_data zynqmp_uart_def = { + .quirks = CDNS_UART_RXBS_SUPPORT, }; + +/* Match table for of_platform binding */ +static const struct of_device_id cdns_uart_of_match[] = { + { .compatible = "xlnx,xuartps", }, + { .compatible = "cdns,uart-r1p8", }, + { .compatible = "cdns,uart-r1p12", .data = &zynqmp_uart_def }, + {} +}; +MODULE_DEVICE_TABLE(of, cdns_uart_of_match); + /** * cdns_uart_probe - Platform driver probe * @pdev: Pointer to the platform device structure @@ -1340,12 +1454,20 @@ static int cdns_uart_probe(struct platform_device *pdev) struct uart_port *port; struct resource *res; struct cdns_uart *cdns_uart_data; + const struct of_device_id *match; cdns_uart_data = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_data), GFP_KERNEL); if (!cdns_uart_data) return -ENOMEM; + match = of_match_node(cdns_uart_of_match, pdev->dev.of_node); + if (match && match->data) { + const struct cdns_platform_data *data = match->data; + + cdns_uart_data->quirks = data->quirks; + } + cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "pclk"); if (IS_ERR(cdns_uart_data->pclk)) { cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "aper_clk"); @@ -1471,14 +1593,6 @@ static int cdns_uart_remove(struct platform_device *pdev) return rc; } -/* Match table for of_platform binding */ -static const struct of_device_id cdns_uart_of_match[] = { - { .compatible = "xlnx,xuartps", }, - { .compatible = "cdns,uart-r1p8", }, - {} -}; -MODULE_DEVICE_TABLE(of, cdns_uart_of_match); - static struct platform_driver cdns_uart_platform_driver = { .probe = cdns_uart_probe, .remove = cdns_uart_remove, |