lkml.org 
[lkml]   [2024]   [Apr]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/3] tty: serial: uartps: Add support for uartps controller reset
Date
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 <manikanta.guntupalli@amd.com>
---
drivers/tty/serial/xilinx_uartps.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index de3487206bcb..e45d6993ba05 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -25,6 +25,7 @@
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/delay.h>
+#include <linux/reset.h>

#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 +951,12 @@ static int cdns_uart_startup(struct uart_port *port)

is_brk_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;

+ if (cdns_uart->rstc) {
+ ret = reset_control_deassert(cdns_uart->rstc);
+ if (ret)
+ return ret;
+ }
+
uart_port_lock_irqsave(port, &flags);

/* Disable the TX and RX */
@@ -1721,6 +1730,13 @@ 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 +1897,7 @@ 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);
--
2.25.1

\
 
 \ /
  Last update: 2024-05-27 16:47    [W:0.074 / U:0.156 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site