From e3896be240780ccade65cc6cc8925c6f12e7f6c6 Mon Sep 17 00:00:00 2001 From: Manikanta Guntupalli Date: Thu, 25 Apr 2024 11:53:58 +0530 Subject: tty: serial: uartps: Add support for uartps controller reset Add support for an optional reset for the uartps controller using the reset driver. If the uartps node contains the "resets" property, then cdns_uart_startup performs uartps controller non-pulse out of reset and reset in exit path. Signed-off-by: Manikanta Guntupalli Link: https://lore.kernel.org/r/20240425062358.1347684-4-manikanta.guntupalli@amd.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/xilinx_uartps.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index de3487206bcb..2acfcea403ce 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -25,6 +25,7 @@ #include #include #include +#include #define CDNS_UART_TTY_NAME "ttyPS" #define CDNS_UART_NAME "xuartps" @@ -198,6 +199,7 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255"); * @gpiod_rts: Pointer to the gpio descriptor * @rs485_tx_started: RS485 tx state * @tx_timer: Timer for tx + * @rstc: Pointer to the reset control */ struct cdns_uart { struct uart_port *port; @@ -211,6 +213,7 @@ struct cdns_uart { struct gpio_desc *gpiod_rts; bool rs485_tx_started; struct hrtimer tx_timer; + struct reset_control *rstc; }; struct cdns_platform_data { u32 quirks; @@ -948,6 +951,10 @@ static int cdns_uart_startup(struct uart_port *port) is_brk_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT; + ret = reset_control_deassert(cdns_uart->rstc); + if (ret) + return ret; + uart_port_lock_irqsave(port, &flags); /* Disable the TX and RX */ @@ -1721,6 +1728,13 @@ static int cdns_uart_probe(struct platform_device *pdev) dev_err(&pdev->dev, "clock name 'ref_clk' is deprecated.\n"); } + cdns_uart_data->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); + if (IS_ERR(cdns_uart_data->rstc)) { + rc = PTR_ERR(cdns_uart_data->rstc); + dev_err_probe(&pdev->dev, rc, "Cannot get UART reset\n"); + goto err_out_unregister_driver; + } + rc = clk_prepare_enable(cdns_uart_data->pclk); if (rc) { dev_err(&pdev->dev, "Unable to enable pclk clock.\n"); @@ -1881,6 +1895,7 @@ static void cdns_uart_remove(struct platform_device *pdev) if (console_port == port) console_port = NULL; #endif + reset_control_assert(cdns_uart_data->rstc); if (!--instances) uart_unregister_driver(cdns_uart_data->cdns_uart_driver); -- cgit v1.2.3