diff options
Diffstat (limited to 'drivers/tty/serial/fsl_lpuart.c')
-rw-r--r-- | drivers/tty/serial/fsl_lpuart.c | 88 |
1 files changed, 55 insertions, 33 deletions
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 13e705b53217..9230d96ed3cd 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -233,8 +233,6 @@ /* IMX lpuart has four extra unused regs located at the beginning */ #define IMX_REG_OFF 0x10 -static DEFINE_IDA(fsl_lpuart_ida); - enum lpuart_type { VF610_LPUART, LS1021A_LPUART, @@ -269,7 +267,6 @@ struct lpuart_port { int rx_dma_rng_buf_len; unsigned int dma_tx_nents; wait_queue_head_t dma_wait; - bool id_allocated; }; struct lpuart_soc_data { @@ -810,11 +807,17 @@ static unsigned int lpuart32_tx_empty(struct uart_port *port) struct lpuart_port, port); unsigned long stat = lpuart32_read(port, UARTSTAT); unsigned long sfifo = lpuart32_read(port, UARTFIFO); + unsigned long ctrl = lpuart32_read(port, UARTCTRL); if (sport->dma_tx_in_progress) return 0; - if (stat & UARTSTAT_TC && sfifo & UARTFIFO_TXEMPT) + /* + * LPUART Transmission Complete Flag may never be set while queuing a break + * character, so avoid checking for transmission complete when UARTCTRL_SBK + * is asserted. + */ + if ((stat & UARTSTAT_TC && sfifo & UARTFIFO_TXEMPT) || ctrl & UARTCTRL_SBK) return TIOCSER_TEMT; return 0; @@ -1020,8 +1023,8 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport) unsigned long sr = lpuart32_read(&sport->port, UARTSTAT); if (sr & (UARTSTAT_PE | UARTSTAT_FE)) { - /* Read DR to clear the error flags */ - lpuart32_read(&sport->port, UARTDATA); + /* Clear the error flags */ + lpuart32_write(&sport->port, sr, UARTSTAT); if (sr & UARTSTAT_PE) sport->port.icount.parity++; @@ -1169,7 +1172,7 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport) * 10ms at any baud rate. */ sport->rx_dma_rng_buf_len = (DMA_RX_TIMEOUT * baud / bits / 1000) * 2; - sport->rx_dma_rng_buf_len = (1 << (fls(sport->rx_dma_rng_buf_len) - 1)); + sport->rx_dma_rng_buf_len = (1 << fls(sport->rx_dma_rng_buf_len)); if (sport->rx_dma_rng_buf_len < 16) sport->rx_dma_rng_buf_len = 16; @@ -1280,9 +1283,9 @@ static int lpuart_config_rs485(struct uart_port *port, * Note: UART is assumed to be active high. */ if (rs485->flags & SER_RS485_RTS_ON_SEND) - modem &= ~UARTMODEM_TXRTSPOL; - else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) modem |= UARTMODEM_TXRTSPOL; + else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) + modem &= ~UARTMODEM_TXRTSPOL; } /* Store the new configuration */ @@ -1375,12 +1378,34 @@ static void lpuart32_break_ctl(struct uart_port *port, int break_state) { unsigned long temp; - temp = lpuart32_read(port, UARTCTRL) & ~UARTCTRL_SBK; - - if (break_state != 0) - temp |= UARTCTRL_SBK; + temp = lpuart32_read(port, UARTCTRL); - lpuart32_write(port, temp, UARTCTRL); + /* + * LPUART IP now has two known bugs, one is CTS has higher priority than the + * break signal, which causes the break signal sending through UARTCTRL_SBK + * may impacted by the CTS input if the HW flow control is enabled. It + * exists on all platforms we support in this driver. + * Another bug is i.MX8QM LPUART may have an additional break character + * being sent after SBK was cleared. + * To avoid above two bugs, we use Transmit Data Inversion function to send + * the break signal instead of UARTCTRL_SBK. + */ + if (break_state != 0) { + /* + * Disable the transmitter to prevent any data from being sent out + * during break, then invert the TX line to send break. + */ + temp &= ~UARTCTRL_TE; + lpuart32_write(port, temp, UARTCTRL); + temp |= UARTCTRL_TXINV; + lpuart32_write(port, temp, UARTCTRL); + } else { + /* Disable the TXINV to turn off break and re-enable transmitter. */ + temp &= ~UARTCTRL_TXINV; + lpuart32_write(port, temp, UARTCTRL); + temp |= UARTCTRL_TE; + lpuart32_write(port, temp, UARTCTRL); + } } static void lpuart_setup_watermark(struct lpuart_port *sport) @@ -1596,6 +1621,7 @@ static void lpuart_dma_shutdown(struct lpuart_port *sport) if (sport->lpuart_dma_rx_use) { del_timer_sync(&sport->lpuart_timer); lpuart_dma_rx_free(&sport->port); + sport->lpuart_dma_rx_use = false; } if (sport->lpuart_dma_tx_use) { @@ -1604,6 +1630,7 @@ static void lpuart_dma_shutdown(struct lpuart_port *sport) sport->dma_tx_in_progress = false; dmaengine_terminate_all(sport->dma_tx_chan); } + sport->lpuart_dma_tx_use = false; } } @@ -1983,8 +2010,15 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios, /* update the per-port timeout */ uart_update_timeout(port, termios->c_cflag, baud); - /* wait transmit engin complete */ - lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC); + /* + * LPUART Transmission Complete Flag may never be set while queuing a break + * character, so skip waiting for transmission complete when UARTCTRL_SBK is + * asserted. + */ + if (!(old_ctrl & UARTCTRL_SBK)) { + lpuart32_write(&sport->port, 0, UARTMODIR); + lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC); + } /* disable transmit and receive */ lpuart32_write(&sport->port, old_ctrl & ~(UARTCTRL_TE | UARTCTRL_RE), @@ -2375,6 +2409,7 @@ static int __init lpuart32_imx_early_console_setup(struct earlycon_device *devic OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup); OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup); OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup); +OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8ulp-lpuart", lpuart32_imx_early_console_setup); OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8qxp-lpuart", lpuart32_imx_early_console_setup); EARLYCON_DECLARE(lpuart, lpuart_early_console_setup); EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup); @@ -2450,23 +2485,18 @@ static int lpuart_probe(struct platform_device *pdev) ret = of_alias_get_id(np, "serial"); if (ret < 0) { - ret = ida_simple_get(&fsl_lpuart_ida, 0, UART_NR, GFP_KERNEL); - if (ret < 0) { - dev_err(&pdev->dev, "port line is full, add device failed\n"); - return ret; - } - sport->id_allocated = true; + dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret); + return ret; } if (ret >= ARRAY_SIZE(lpuart_ports)) { dev_err(&pdev->dev, "serial%d out of range\n", ret); - ret = -EINVAL; - goto failed_out_of_range; + return -EINVAL; } sport->port.line = ret; ret = lpuart_enable_clks(sport); if (ret) - goto failed_clock_enable; + return ret; sport->port.uartclk = lpuart_get_baud_clk_rate(sport); lpuart_ports[sport->port.line] = sport; @@ -2516,10 +2546,6 @@ static int lpuart_probe(struct platform_device *pdev) failed_attach_port: failed_irq_request: lpuart_disable_clks(sport); -failed_clock_enable: -failed_out_of_range: - if (sport->id_allocated) - ida_simple_remove(&fsl_lpuart_ida, sport->port.line); return ret; } @@ -2529,9 +2555,6 @@ static int lpuart_remove(struct platform_device *pdev) uart_remove_one_port(&lpuart_reg, &sport->port); - if (sport->id_allocated) - ida_simple_remove(&fsl_lpuart_ida, sport->port.line); - lpuart_disable_clks(sport); if (sport->dma_tx_chan) @@ -2663,7 +2686,6 @@ static int __init lpuart_serial_init(void) static void __exit lpuart_serial_exit(void) { - ida_destroy(&fsl_lpuart_ida); platform_driver_unregister(&lpuart_driver); uart_unregister_driver(&lpuart_reg); } |