[PATCH 0/3] Add support for uartps controller reset

[PATCH 0/3] Add support for uartps controller reset

[Manikanta Guntupalli]

Add optional resets property for UART nodes.
Add support for uartps controller reset.

Manikanta Guntupalli (3):
  dt-bindings: serial: cdsn,uart: Add optional reset property
  arm64: zynqmp: Add resets property for UART nodes
  tty: serial: uartps: Add support for uartps controller reset

 .../devicetree/bindings/serial/cdns,uart.yaml   |  3 +++
 arch/arm64/boot/dts/xilinx/zynqmp.dtsi          |  2 ++
 drivers/tty/serial/xilinx_uartps.c              | 17 +++++++++++++++++
 3 files changed, 22 insertions(+)

-- 
2.25.1

[PATCH 1/3] dt-bindings: serial: cdsn,uart: Add optional reset property

[Manikanta Guntupalli]

Add optional reset device-tree property to the uartps controller.

Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
---
 Documentation/devicetree/bindings/serial/cdns,uart.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/serial/cdns,uart.yaml b/Documentation/devicetree/bindings/serial/cdns,uart.yaml
index 2129247d7c81..d7f047b0bf24 100644
--- a/Documentation/devicetree/bindings/serial/cdns,uart.yaml
+++ b/Documentation/devicetree/bindings/serial/cdns,uart.yaml
@@ -46,6 +46,9 @@ properties:
   power-domains:
     maxItems: 1
 
+  resets:
+    maxItems: 1
+
 required:
   - compatible
   - reg
-- 
2.25.1

Re: [PATCH 1/3] dt-bindings: serial: cdsn,uart: Add optional reset property

[Krzysztof Kozlowski]

On 19/04/2024 14:05, Manikanta Guntupalli wrote:
> Add optional reset device-tree property to the uartps controller.
> 
> Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>



Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH 1/3] dt-bindings: serial: cdsn,uart: Add optional reset property

[Mukesh Kumar Savaliya]

On 4/19/2024 5:35 PM, Manikanta Guntupalli wrote:
> Add optional reset device-tree property to the uartps controller.
what exactly is uartps ? i Couldn't get from google too.
> 
> Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
> ---
>   Documentation/devicetree/bindings/serial/cdns,uart.yaml | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/serial/cdns,uart.yaml b/Documentation/devicetree/bindings/serial/cdns,uart.yaml
> index 2129247d7c81..d7f047b0bf24 100644
> --- a/Documentation/devicetree/bindings/serial/cdns,uart.yaml
> +++ b/Documentation/devicetree/bindings/serial/cdns,uart.yaml
> @@ -46,6 +46,9 @@ properties:
>     power-domains:
>       maxItems: 1
>   
> +  resets:
> +    maxItems: 1
> +
>   required:
>     - compatible
>     - reg

[PATCH 2/3] arm64: zynqmp: Add resets property for UART nodes

[Manikanta Guntupalli]

Add resets property for UART0 and UART1 nodes

Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
---
 arch/arm64/boot/dts/xilinx/zynqmp.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/xilinx/zynqmp.dtsi b/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
index 25d20d803230..935504424ec6 100644
--- a/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
+++ b/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
@@ -906,6 +906,7 @@ uart0: serial@ff000000 {
 			reg = <0x0 0xff000000 0x0 0x1000>;
 			clock-names = "uart_clk", "pclk";
 			power-domains = <&zynqmp_firmware PD_UART_0>;
+			resets = <&zynqmp_reset ZYNQMP_RESET_UART0>;
 		};
 
 		uart1: serial@ff010000 {
@@ -917,6 +918,7 @@ uart1: serial@ff010000 {
 			reg = <0x0 0xff010000 0x0 0x1000>;
 			clock-names = "uart_clk", "pclk";
 			power-domains = <&zynqmp_firmware PD_UART_1>;
+			resets = <&zynqmp_reset ZYNQMP_RESET_UART1>;
 		};
 
 		usb0: usb@ff9d0000 {
-- 
2.25.1

[PATCH 3/3] tty: serial: uartps: Add support for uartps controller reset

[Manikanta Guntupalli]

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

RE: [PATCH 3/3] tty: serial: uartps: Add support for uartps controller reset

[Pandey, Radhey Shyam]

> -----Original Message-----
> From: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
> Sent: Friday, April 19, 2024 5:36 PM
> To: git (AMD-Xilinx) <git@amd.com>; gregkh@linuxfoundation.org;
> jirislaby@kernel.org; robh@kernel.org; krzk+dt@kernel.org;
> conor+dt@kernel.org; Simek, Michal <michal.simek@amd.com>;
> p.zabel@pengutronix.de; laurent.pinchart@ideasonboard.com; Pandey,
> Radhey Shyam <radhey.shyam.pandey@amd.com>; Gajjar, Parth
> <parth.gajjar@amd.com>; u.kleine-koenig@pengutronix.de;
> tglx@linutronix.de; julien.malik@unseenlabs.fr; ruanjinjie@huawei.com;
> linux-kernel@vger.kernel.org; linux-serial@vger.kernel.org;
> devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org
> Cc: Goud, Srinivas <srinivas.goud@amd.com>; Datta, Shubhrajyoti
> <shubhrajyoti.datta@amd.com>; manion05gk@gmail.com; Guntupalli,
> Manikanta <manikanta.guntupalli@amd.com>
> Subject: [PATCH 3/3] 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 <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);

reset_control_deassert already has NULL check , then any need for this additional
if check?


> +		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