Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates
 12.22.5.236 as permitted sender) receiver=protection.outlook.com;
 client-ip=12.22.5.236; helo=mail.nvidia.com;
From:   Akhil R <akhilrajeev@nvidia.com>
To:     <u.kleine-koenig@pengutronix.de>, <andy.shevchenko@gmail.com>,
        <christian.koenig@amd.com>, <digetx@gmail.com>,
        <gregkh@linuxfoundation.org>, <jonathanh@nvidia.com>,
        <ldewangan@nvidia.com>, <lenb@kernel.org>,
        <linux-acpi@vger.kernel.org>, <linux-i2c@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
        <rafael@kernel.org>, <sumit.semwal@linaro.org>,
        <thierry.reding@gmail.com>, <wsa@kernel.org>
CC:     <akhilrajeev@nvidia.com>
Subject: [PATCH v3 2/3] docs: firmware-guide: ACPI: Add named interrupt doc
Date:   Thu, 20 Jan 2022 19:14:14 +0530
Message-ID: <1642686255-25951-3-git-send-email-akhilrajeev@nvidia.com>
In-Reply-To: <1642686255-25951-1-git-send-email-akhilrajeev@nvidia.com>
References: <1642686255-25951-1-git-send-email-akhilrajeev@nvidia.com>
MIME-Version: 1.0
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jan 2022 13:45:17.3754
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 0f2f489f-d783-429f-361e-08d9dc1b180c
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[12.22.5.236];Helo=[mail.nvidia.com]
X-MS-Exchange-CrossTenant-AuthSource: BN8NAM11FT039.eop-nam11.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR12MB4160
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Added details and example for named interrupts in the ACPI table.

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
---
 Documentation/firmware-guide/acpi/enumeration.rst | 38 +++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/Documentation/firmware-guide/acpi/enumeration.rst b/Documentation/firmware-guide/acpi/enumeration.rst
index 74b830b2..595deba 100644
--- a/Documentation/firmware-guide/acpi/enumeration.rst
+++ b/Documentation/firmware-guide/acpi/enumeration.rst
@@ -143,6 +143,44 @@ In robust cases the client unfortunately needs to call
 acpi_dma_request_slave_chan_by_index() directly and therefore choose the
 specific FixedDMA resource by its index.
 
+Named Interrupts
+================
+
+Drivers enumerated via ACPI can have names to interrupts in the ACPI table
+which can be used to get the IRQ number in the driver.
+
+The interrupt name can be listed in _DSD as 'interrupt-names'. The names
+should be listed as an array of strings which will map to the Interrupt()
+resource in the ACPI table corresponding to its index.
+
+The table below shows an example of its usage::
+
+    Device (DEV0) {
+        ...
+        Name (_CRS, ResourceTemplate() {
+            ...
+            Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive) {
+                0x20,
+                0x24
+            }
+        })
+
+        Name (_DSD, Package () {
+            ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+            Package () {
+                Package () {"interrupt-names",
+                Package (2) {"default", "alert"}},
+            }
+        ...
+        })
+    }
+
+The interrupt name 'default' will correspond to 0x20 in Interrupt()
+resource and 'alert' to 0x24.
+
+The driver can call the function - device_irq_get_byname() with the device
+and interrupt name as arguments to get the corresponding IRQ number.
+
 SPI serial bus support
 ======================
 
-- 
2.7.4