From nobody Mon Feb 9 11:06:33 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7F50327281E; Mon, 26 Jan 2026 19:32:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769455977; cv=none; b=ixhTrOb8bIqRxPI8qDszp3EVSGuQdoG1g5KhmxQ28ins1w/9/hgbI03Ir2ruL9fruHs8FFRhUdN3TNmWybMp74VI1HYnPzECSuSIc+QM20FlaLYpCOQbZxY7N2bk2x4xNZlmBuu6gl2+EiZ8E8zcBilXYf0Qil8stylg7CcrEQs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769455977; c=relaxed/simple; bh=KIW8/dKTa1YNKlK58MwInmmKjgMUS2SczSqpAXZtH4A=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=hdnSZFH3dK2/5g60Hr5QinqUWAUznuOsT9KEl6RYe6WbyQvflYtUZt32O7fSH8VXdJ/4hmX9lEGMoO1ajJj3hZBwO+kbAeNUwGJ8K3GW7dzGVY/cEZP1rv6GDAItognqLaqUhm9l9qW9SjYgBQ6i1llyx7wTDgrlSUHEdvC4KaU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DnOu60tL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DnOu60tL" Received: by smtp.kernel.org (Postfix) with ESMTPS id 5DE5DC2BC86; Mon, 26 Jan 2026 19:32:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769455977; bh=KIW8/dKTa1YNKlK58MwInmmKjgMUS2SczSqpAXZtH4A=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=DnOu60tLBuDDNaxPi3r20WL38rLAJkPcvw15iWAKjKH+vGO/JMqa8GiLJAfRtsxeS ovtBYgKA8C9yVaBJMjzlNamzZ6qjH5GsHm6DR6L4afNHGaL3NB3ViMmY4Bb2hhE/OY wj2OQc5oNP1+ezEcWecjLvg58b4E+n6OrtsvVETwGIafHlUYx6vqim6+3KRGYbfib9 7zhZKiE2+R+LWBAkNFmBmiVh3dI5n/l3NUzk2xkzMw2a0IgYUFiRB2uI+53WkygDE4 lgSG3zr5LkRXOFue5x9zekA3pO8LU3C7HXOs8JTm95JZxszLNJY8H8lgFBsmdFVS6Q D7jNZJZAxdwbQ== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54E92D19518; Mon, 26 Jan 2026 19:32:57 +0000 (UTC) From: Shrikant Raskar via B4 Relay Date: Tue, 27 Jan 2026 01:02:20 +0530 Subject: [PATCH v7 6/6] iio: proximity: rfd77402: Add interrupt handling support Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260127-b4-rfd77402_v5-v7-6-3e7f2d452da2@gmail.com> References: <20260127-b4-rfd77402_v5-v7-0-3e7f2d452da2@gmail.com> In-Reply-To: <20260127-b4-rfd77402_v5-v7-0-3e7f2d452da2@gmail.com> To: Jonathan Cameron , David Lechner , =?utf-8?q?Nuno_S=C3=A1?= , Andy Shevchenko Cc: skhan@linuxfoundation.org, david.hunter.linux@gmail.com, raskar.shree97@gmail.com, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1769455974; l=6529; i=raskar.shree97@gmail.com; s=20260101; h=from:subject:message-id; bh=PXRuCHQwhL0RvoseV0P0rP1fSG0LvtG292soIV5X2ZE=; b=HFphvdYoSUNInrvf9j6d4SOGmCHBKv6z0JvGECmHnUj5x1jFFfKXIAkbcVhHMv3qJWqj/hWNn yIToHCuJFAeCBSjJpWl+N1tF11fC0+8/qeX1WtYexXMUPKRKvBdHBmf X-Developer-Key: i=raskar.shree97@gmail.com; a=ed25519; pk=4m2wXDvY0vlXefvRRzawNcNAif88Cy4XvbLkU6iMG/Y= X-Endpoint-Received: by B4 Relay for raskar.shree97@gmail.com/20260101 with auth_id=589 X-Original-From: Shrikant Raskar Reply-To: raskar.shree97@gmail.com From: Shrikant Raskar Add interrupt handling support to enable event-driven data acquisition instead of continuous polling. This improves responsiveness, reduces CPU overhead, and supports low-power operation by allowing the system to remain idle until an interrupt occurs. Signed-off-by: Shrikant Raskar Reviewed-by: Andy Shevchenko --- drivers/iio/proximity/rfd77402.c | 121 +++++++++++++++++++++++++++++++++++= +--- 1 file changed, 113 insertions(+), 8 deletions(-) diff --git a/drivers/iio/proximity/rfd77402.c b/drivers/iio/proximity/rfd77= 402.c index c29ae9af4a90..53dff934d66d 100644 --- a/drivers/iio/proximity/rfd77402.c +++ b/drivers/iio/proximity/rfd77402.c @@ -6,20 +6,28 @@ * * 7-bit I2C slave address 0x4c * - * TODO: interrupt * https://media.digikey.com/pdf/Data%20Sheets/RF%20Digital%20PDFs/RFD7740= 2.pdf */ =20 +#include +#include #include +#include +#include #include +#include #include +#include #include +#include =20 #include =20 #define RFD77402_DRV_NAME "rfd77402" =20 #define RFD77402_ICSR 0x00 /* Interrupt Control Status Register */ +#define RFD77402_ICSR_CLR_CFG BIT(0) +#define RFD77402_ICSR_CLR_TYPE BIT(1) #define RFD77402_ICSR_INT_MODE BIT(2) #define RFD77402_ICSR_INT_POL BIT(3) #define RFD77402_ICSR_RESULT BIT(4) @@ -27,6 +35,12 @@ #define RFD77402_ICSR_H2M_MSG BIT(6) #define RFD77402_ICSR_RESET BIT(7) =20 +#define RFD77402_IER 0x02 +#define RFD77402_IER_RESULT BIT(0) +#define RFD77402_IER_M2H_MSG BIT(1) +#define RFD77402_IER_H2M_MSG BIT(2) +#define RFD77402_IER_RESET BIT(3) + #define RFD77402_CMD_R 0x04 #define RFD77402_CMD_SINGLE 0x01 #define RFD77402_CMD_STANDBY 0x10 @@ -81,10 +95,14 @@ static const struct { * struct rfd77402_data - device-specific data for the RFD77402 sensor * @client: I2C client handle * @lock: mutex to serialize sensor reads + * @completion: completion used for interrupt-driven measurements + * @irq_en: indicates whether interrupt mode is enabled */ struct rfd77402_data { struct i2c_client *client; struct mutex lock; + struct completion completion; + bool irq_en; }; =20 static const struct iio_chan_spec rfd77402_channels[] =3D { @@ -95,6 +113,41 @@ static const struct iio_chan_spec rfd77402_channels[] = =3D { }, }; =20 +static irqreturn_t rfd77402_interrupt_handler(int irq, void *pdata) +{ + struct rfd77402_data *data =3D pdata; + int ret; + + ret =3D i2c_smbus_read_byte_data(data->client, RFD77402_ICSR); + if (ret < 0) + return IRQ_NONE; + + /* Check if the interrupt is from our device */ + if (!(ret & RFD77402_ICSR_RESULT)) + return IRQ_NONE; + + /* Signal completion of measurement */ + complete(&data->completion); + return IRQ_HANDLED; +} + +static int rfd77402_wait_for_irq(struct rfd77402_data *data) +{ + int ret; + + /* + * According to RFD77402 Datasheet v1.8, + * Section 3.1.1 "Single Measure" (Figure: Single Measure Flow Chart), + * the suggested timeout for single measure is 100 ms. + */ + ret =3D wait_for_completion_timeout(&data->completion, + msecs_to_jiffies(100)); + if (ret =3D=3D 0) + return -ETIMEDOUT; + + return 0; +} + static int rfd77402_set_state(struct i2c_client *client, u8 state, u16 che= ck) { int ret; @@ -120,6 +173,11 @@ static int rfd77402_wait_for_result(struct rfd77402_da= ta *data) struct i2c_client *client =3D data->client; int val, ret; =20 + if (data->irq_en) { + reinit_completion(&data->completion); + return rfd77402_wait_for_irq(data); + } + ret =3D read_poll_timeout(i2c_smbus_read_byte_data, val, (val < 0) || (val & RFD77402_ICSR_RESULT), 10 * USEC_PER_MSEC, @@ -200,8 +258,20 @@ static const struct iio_info rfd77402_info =3D { .read_raw =3D rfd77402_read_raw, }; =20 -static int rfd77402_init(struct i2c_client *client) +static int rfd77402_config_irq(struct i2c_client *client, u8 csr, u8 ier) { + int ret; + + ret =3D i2c_smbus_write_byte_data(client, RFD77402_ICSR, csr); + if (ret) + return ret; + + return i2c_smbus_write_byte_data(client, RFD77402_IER, ier); +} + +static int rfd77402_init(struct rfd77402_data *data) +{ + struct i2c_client *client =3D data->client; int ret, i; =20 ret =3D rfd77402_set_state(client, RFD77402_CMD_STANDBY, @@ -209,10 +279,26 @@ static int rfd77402_init(struct i2c_client *client) if (ret < 0) return ret; =20 - /* configure INT pad as push-pull, active low */ - ret =3D i2c_smbus_write_byte_data(client, RFD77402_ICSR, - RFD77402_ICSR_INT_MODE); - if (ret < 0) + if (data->irq_en) { + /* + * Enable interrupt mode: + * - Configure ICSR for auto-clear on read and + * push-pull output + * - Enable "result ready" interrupt in IER + */ + ret =3D rfd77402_config_irq(client, + RFD77402_ICSR_CLR_CFG | + RFD77402_ICSR_INT_MODE, + RFD77402_IER_RESULT); + } else { + /* + * Disable all interrupts: + * - Clear ICSR configuration + * - Disable all interrupts in IER + */ + ret =3D rfd77402_config_irq(client, 0, 0); + } + if (ret) return ret; =20 /* I2C configuration */ @@ -292,13 +378,29 @@ static int rfd77402_probe(struct i2c_client *client) if (ret) return ret; =20 + init_completion(&data->completion); + + if (client->irq > 0) { + ret =3D devm_request_threaded_irq(&client->dev, client->irq, + NULL, rfd77402_interrupt_handler, + IRQF_ONESHOT, + "rfd77402", data); + if (ret) + return ret; + + data->irq_en =3D true; + dev_dbg(&client->dev, "Using interrupt mode\n"); + } else { + dev_dbg(&client->dev, "Using polling mode\n"); + } + indio_dev->info =3D &rfd77402_info; indio_dev->channels =3D rfd77402_channels; indio_dev->num_channels =3D ARRAY_SIZE(rfd77402_channels); indio_dev->name =3D RFD77402_DRV_NAME; indio_dev->modes =3D INDIO_DIRECT_MODE; =20 - ret =3D rfd77402_init(client); + ret =3D rfd77402_init(data); if (ret < 0) return ret; =20 @@ -316,7 +418,10 @@ static int rfd77402_suspend(struct device *dev) =20 static int rfd77402_resume(struct device *dev) { - return rfd77402_init(to_i2c_client(dev)); + struct iio_dev *indio_dev =3D dev_get_drvdata(dev); + struct rfd77402_data *data =3D iio_priv(indio_dev); + + return rfd77402_init(data); } =20 static DEFINE_SIMPLE_DEV_PM_OPS(rfd77402_pm_ops, rfd77402_suspend, --=20 2.43.0