On 20. 10. 22, 15:19, Sherry Sun wrote:
@@ -2636,6 +2610,54 @@ static const struct serial_rs485 lpuart_rs485_supported = { /* delay_rts_* and RX_DURING_TX are not supported */ };+static int lpuart_global_reset(struct lpuart_port *sport)+{ + struct uart_port *port = &sport->port; + void __iomem *global_addr; + unsigned long ctrl, bd; + unsigned int val = 0; + int ret; + + ret = clk_prepare_enable(sport->ipg_clk); + if (ret) { + dev_err(sport->port.dev, "failed to enable uart ipg clk: %d\n", ret); + return ret; + } + + if (is_imx7ulp_lpuart(sport) || is_imx8qxp_lpuart(sport)) { + /* + * If the transmitter is used by earlycon, wait for transmit engine to + * complete and then reset. + */ + ctrl = lpuart32_read(port, UARTCTRL); + if (ctrl & UARTCTRL_TE) { + bd = lpuart32_read(&sport->port, UARTBAUD); + if (read_poll_timeout_atomic(lpuart32_tx_empty, val, val, 1, 100000, + false, port)) {
Ah, this is not atomic context (clk_prepare_enable() above and usleep_range() below), so no need for _atomic here too.
thanks, -- js suse labs
