Received-SPF: pass (google.com: domain of linux-kernel+bounces-152354-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
From: "Pandey, Radhey Shyam" <radhey.shyam.pandey@amd.com>
To: "Guntupalli, Manikanta" <manikanta.guntupalli@amd.com>, "git (AMD-Xilinx)"
	<git@amd.com>, "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
	"jirislaby@kernel.org" <jirislaby@kernel.org>, "robh@kernel.org"
	<robh@kernel.org>, "krzk+dt@kernel.org" <krzk+dt@kernel.org>,
	"conor+dt@kernel.org" <conor+dt@kernel.org>, "Simek, Michal"
	<michal.simek@amd.com>, "p.zabel@pengutronix.de" <p.zabel@pengutronix.de>,
	"laurent.pinchart@ideasonboard.com" <laurent.pinchart@ideasonboard.com>,
	"Gajjar, Parth" <parth.gajjar@amd.com>, "u.kleine-koenig@pengutronix.de"
	<u.kleine-koenig@pengutronix.de>, "tglx@linutronix.de" <tglx@linutronix.de>,
	"julien.malik@unseenlabs.fr" <julien.malik@unseenlabs.fr>,
	"ruanjinjie@huawei.com" <ruanjinjie@huawei.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>
CC: "Goud, Srinivas" <srinivas.goud@amd.com>, "Datta, Shubhrajyoti"
	<shubhrajyoti.datta@amd.com>, "manion05gk@gmail.com" <manion05gk@gmail.com>,
	"Guntupalli, Manikanta" <manikanta.guntupalli@amd.com>
Subject: RE: [PATCH 3/3] tty: serial: uartps: Add support for uartps
 controller reset
Thread-Topic: [PATCH 3/3] tty: serial: uartps: Add support for uartps
 controller reset
Thread-Index: AQHaklIJX+674eaJ10uDWbb88wDDkLFxhBPA
Date: Sat, 20 Apr 2024 19:04:11 +0000
Message-ID:
 <MN0PR12MB5953AED63BC895B09D90DED7B70C2@MN0PR12MB5953.namprd12.prod.outlook.com>
References: <20240419120531.3775919-1-manikanta.guntupalli@amd.com>
 <20240419120531.3775919-4-manikanta.guntupalli@amd.com>
In-Reply-To: <20240419120531.3775919-4-manikanta.guntupalli@amd.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0:
 =?us-ascii?Q?2qc148gnCEr4nvEyrhfUsgyLtig1H8TiqlzdV37EQahoTNLhxhZlKoMMAry2?=
 =?us-ascii?Q?cXfr0SzCUZA06PcN60GeJp+RceeW/H7fjCrGh+RSHzn1f/ffE8L8mjtNqZeP?=
 =?us-ascii?Q?Ptrn43vII1EElA3d2mPE+hUF9p6L1EusLhzt6l+gYLBBp4Vly5PJmFP82FAH?=
 =?us-ascii?Q?7nri5RbSL9SBW7xasqEwiEmKGSTUiAEMq0Yx7XcwE0eM29W4GpRPy7TP8xn0?=
 =?us-ascii?Q?YjnOUwd3GtjwD4se3rQHP1QafiyixS4eq+V8NmwxSUjJvc6tKIz49aC9Fkub?=
 =?us-ascii?Q?KuGPuno99uGulFed3P4IouJlYe2htp5KbJJe65GrTemAwB7Mdbdbx/8HpYgU?=
 =?us-ascii?Q?jBwuyMiPoXy3qUeMu4mcbOcjs5ceWJYhgN9AQIltp/aQ6j3oEOAT0XkhGJk9?=
 =?us-ascii?Q?E6I7gv9jMx6Cks3jIw+h1D92kLptw4JF2mBPvmGUVRQ7j4AYyVbiLYnSsgtW?=
 =?us-ascii?Q?v9WmnugffcVioYIE5cbxOxBqfwOwpC8FbAyAovvLChmP+DSPqFOmPbv9LO2m?=
 =?us-ascii?Q?DAgouigV3EF5eYbZiPgNLfSk5se2NiEvyCT3jXC1VK1BUIWrU1JsR1k0Klfd?=
 =?us-ascii?Q?Tgki9ebH+gx59Z7lCMOiHJRADDt+ixxEqO2vHR4k9CtHTQderH0FHGWuicBD?=
 =?us-ascii?Q?yVF9XKy0I0SBLGSGBdYnUgEV3fjhBpO/Bm9BnxmQa3lR/w6j5EWEstTpAE+k?=
 =?us-ascii?Q?Momurg4e8l1RuEJJ+OKQjkwuVnlQYgmRYxFghQc/Rwf/RD0H50y16MKJqsIg?=
 =?us-ascii?Q?kGS6w6ZhvcemZKm67DkNpcl24E9UsHDUncguMs7G9VP5QRQCmaeKVS796R1A?=
 =?us-ascii?Q?OMelYl6JVCfxjvYPFOB3TPkVzakKfafgLBpLD5qIVaHhXz8WqqnMWCnOtOEo?=
 =?us-ascii?Q?z5dpR87Aii+0KBJcp6c6vAz0z3zDB4NaETQ6Vfh+SugdWwlPSz/7xvZJUmf+?=
 =?us-ascii?Q?o4IU487Be51+0wXIasJMTLwuX7fGBvBtgIoqRNtUrWP5D2yYdTl2v46MWJEZ?=
 =?us-ascii?Q?HqqbGf/8LBS/UFM8uZE0GZGmLB0F/vlgeRQY8OOgty5Bj5HZgz5p6Wr1/Xgz?=
 =?us-ascii?Q?kgd/T8adq6SSD3kDJmYoMSBwYY/7X9gz+W6/hZul+1EbCsdlDNLRGW+HC2Q0?=
 =?us-ascii?Q?oovGKEnnzvnlpkIReWiE3i+Ex1xX39NnLRx9/eF2KpPDaMFZHKBLvOJoXvyo?=
 =?us-ascii?Q?0Z1jVs7dM/fzPqXOl7l9tbg9goLYRomnNsk1KdT7wIUpYBQ25yEUP6Kt+rHg?=
 =?us-ascii?Q?Vo/J7EaxJohnI/qT3WGNRIy+te63qKi0DAjjdNPIjM6j6riM4ZWQ4htjg49I?=
 =?us-ascii?Q?PnjEaeW1I6pYMWO49I8mrEHbqj5Tlk0tY14/BsGLBi3AZUXf0OYFgrt3ZRAc?=
 =?us-ascii?Q?9/K08ART1uW7cUsCcMomrHXuuSZuzMcVLOXyhkVtbTJ3Zc0b2m0meolI8W4+?=
 =?us-ascii?Q?s3YB9NbaM24VmuNvl/PF/A0pXhPqwBhtE4Phd9dG1ZlQL/OmgE1W9KoDi9/G?=
 =?us-ascii?Q?avxOaydzKKAjmTiCldASPDtJQcdRcM1+bKlYTTRTfbvd0QhHmmSFBab6ghgx?=
 =?us-ascii?Q?+tK5+kWu40uewQR+VNY=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk
X-Mailing-List: linux-kernel@vger.kernel.org
List-Id: <linux-kernel.vger.kernel.org>
List-Subscribe: <mailto:linux-kernel+subscribe@vger.kernel.org>
List-Unsubscribe: <mailto:linux-kernel+unsubscribe@vger.kernel.org>
MIME-Version: 1.0
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: MN0PR12MB5953.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 1f005e23-4623-4e0b-250a-08dc616caa1d
X-MS-Exchange-CrossTenant-originalarrivaltime: 20 Apr 2024 19:04:11.7548
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: a+lVSGT9U9OtQA/wfYcqWME4SCdRyjjQfcDh++ueNv8bLtqSmYkmlZ2B4ycO8Hot
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB7600

> -----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 controll=
er
> reset
>=20
> 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.
>=20
> Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
> ---
>  drivers/tty/serial/xilinx_uartps.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>=20
> 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>
>=20
>  #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)
>=20
>  	is_brk_support =3D cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;
>=20
> +	if (cdns_uart->rstc) {
> +		ret =3D reset_control_deassert(cdns_uart->rstc);

reset_control_deassert already has NULL check , then any need for this addi=
tional
if check?


> +		if (ret)
> +			return ret;
> +	}
> +
>  	uart_port_lock_irqsave(port, &flags);
>=20
>  	/* 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");
>  	}
>=20
> +	cdns_uart_data->rstc =3D
> devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
> +	if (IS_ERR(cdns_uart_data->rstc)) {
> +		rc =3D PTR_ERR(cdns_uart_data->rstc);
> +		dev_err_probe(&pdev->dev, rc, "Cannot get UART reset\n");
> +		goto err_out_unregister_driver;
> +	}
> +
>  	rc =3D 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 =3D=3D port)
>  		console_port =3D NULL;
>  #endif
> +	reset_control_assert(cdns_uart_data->rstc);
>=20
>  	if (!--instances)
>  		uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
> --
> 2.25.1