From mboxrd@z Thu Jan 1 00:00:00 1970 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 8FF4E334698; Thu, 15 Jan 2026 08:28:15 +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=1768465695; cv=none; b=rRmMe/qVMz+g3xa4bJZnxGzJaTEkOFrPCnyaNg0Or5Nsz5Da7fVGbdfTUjreLfLfUvWdEwLVoNzi0nleVzQ4KFWhJnatHpSxoTxMV5SriCq4lwTmyjHLcatC+6wRWplxovbhXutWScpN+htU/9+FkIrl0ntNh/jaxrYO7XOdTAs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768465695; c=relaxed/simple; bh=qcVt3Bv5jfMgQ/y4iZfPhQtIVMFB8I5f+l/a4BsqWCY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=bg7nPqPKRbrsRCCqN4cAhu6VSIkJPD3324OPqe5vjr3tF/whRBwOE2605tELs6plxU1dAk8Neelsv9ojN7snqxK9mDrZSTUW3r3ZEM8xDl6T4LdZTcD1kRL3BzDIS9D48q7kV6L070mdIBfaPsNM05Ao86uXnmPaGDYirRRcu6Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EFOSpwvU; 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="EFOSpwvU" Received: by smtp.kernel.org (Postfix) with ESMTPS id BBEC8C2BC9E; Thu, 15 Jan 2026 08:28:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768465694; bh=qcVt3Bv5jfMgQ/y4iZfPhQtIVMFB8I5f+l/a4BsqWCY=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=EFOSpwvUNDxS5bPbBcpTE+lIzfst+2x5UCrl1ketCouK27oN36840LrbReaB11y5C A0HAZA0r9PczneUCEBd+s8IxpGIaUSU7bPQUOeng6WRuOwI1p1D0Wa1uVlQ5bINk1y wkY8/JD9gn9jmAQSiANdBboEhNL+5LG8ar83nzLxuEtEwqna9Tzf4GWZiRdjbUTZxy CFN1xRBp342jbWd5Lc5s2HmYlAmV+8Ke7xlBLZ53168KGtqpUYJh08I0uGEfrGdqWE H49oHb/L1KEcLu5oEEfBUPPbXTQ9ezj0fotKNNo49Z7D9MQeeYypKiMETi7XGTANDl fEsPqFAPYrsww== 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 B0EBED39010; Thu, 15 Jan 2026 08:28:14 +0000 (UTC) From: Shrikant Raskar via B4 Relay Date: Thu, 15 Jan 2026 13:57:39 +0530 Subject: [PATCH v5 3/5] 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: 7bit Message-Id: <20260115-rfd77402_v5-v5-3-594eb57683e4@gmail.com> References: <20260115-rfd77402_v5-v5-0-594eb57683e4@gmail.com> In-Reply-To: <20260115-rfd77402_v5-v5-0-594eb57683e4@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=1768465693; l=5569; i=raskar.shree97@gmail.com; s=20260101; h=from:subject:message-id; bh=C3tD21DVcrSgT7m49qVjA0qq6ip8LRECwCOFJRa5kpU=; b=YzqmiZnqruOfQ4IhPBdUKSBTAUT1KokSQay9Ysl8YoAgUAwWHT/0sBRqpR1J+H4FKvHFLZSRj NYx4X11SAP6AKlGixVoxmANGcuQvQBRGmmreRZsDrhFrThX2Z1F7poB 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 --- drivers/iio/proximity/rfd77402.c | 106 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 101 insertions(+), 5 deletions(-) diff --git a/drivers/iio/proximity/rfd77402.c b/drivers/iio/proximity/rfd77402.c index 8c6379bebcc3..dd79c9ee838b 100644 --- a/drivers/iio/proximity/rfd77402.c +++ b/drivers/iio/proximity/rfd77402.c @@ -6,12 +6,13 @@ * * 7-bit I2C slave address 0x4c * - * TODO: interrupt * https://media.digikey.com/pdf/Data%20Sheets/RF%20Digital%20PDFs/RFD77402.pdf */ +#include #include #include +#include #include #include @@ -20,6 +21,8 @@ #define RFD77402_DRV_NAME "rfd77402" #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 +30,12 @@ #define RFD77402_ICSR_H2M_MSG BIT(6) #define RFD77402_ICSR_RESET BIT(7) +#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 @@ -81,6 +90,8 @@ struct rfd77402_data { struct i2c_client *client; /* Serialize reads from the sensor */ struct mutex lock; + struct completion completion; + bool irq_en; }; static const struct iio_chan_spec rfd77402_channels[] = { @@ -91,6 +102,41 @@ static const struct iio_chan_spec rfd77402_channels[] = { }, }; +static irqreturn_t rfd77402_interrupt_handler(int irq, void *pdata) +{ + struct rfd77402_data *data = pdata; + int ret; + + ret = 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 = wait_for_completion_timeout(&data->completion, + msecs_to_jiffies(100)); + if (ret == 0) + return -ETIMEDOUT; + + return 0; +} + static int rfd77402_set_state(struct i2c_client *client, u8 state, u16 check) { int ret; @@ -116,6 +162,11 @@ static int rfd77402_wait_for_result(struct rfd77402_data *data) struct i2c_client *client = data->client; int ret; + if (data->irq_en) { + reinit_completion(&data->completion); + return rfd77402_wait_for_irq(data); + } + return read_poll_timeout(i2c_smbus_read_byte_data, ret, ret & RFD77402_ICSR_RESULT, 10 * USEC_PER_MSEC, @@ -192,8 +243,21 @@ static const struct iio_info rfd77402_info = { .read_raw = rfd77402_read_raw, }; +static int rfd77402_config_irq(struct i2c_client *client, u8 csr, u8 ier) +{ + int ret; + + ret = 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 i2c_client *client) { + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct rfd77402_data *data = iio_priv(indio_dev); int ret, i; ret = rfd77402_set_state(client, RFD77402_CMD_STANDBY, @@ -201,10 +265,26 @@ static int rfd77402_init(struct i2c_client *client) if (ret < 0) return ret; - /* configure INT pad as push-pull, active low */ - ret = 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 = 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 = rfd77402_config_irq(client, 0, 0); + } + if (ret) return ret; /* I2C configuration */ @@ -280,6 +360,22 @@ static int rfd77402_probe(struct i2c_client *client) data = iio_priv(indio_dev); data->client = client; mutex_init(&data->lock); + init_completion(&data->completion); + i2c_set_clientdata(client, indio_dev); + + if (client->irq > 0) { + ret = devm_request_threaded_irq(&client->dev, client->irq, + NULL, rfd77402_interrupt_handler, + IRQF_ONESHOT, + "rfd77402", data); + if (ret) + return ret; + + data->irq_en = true; + dev_dbg(&client->dev, "Using interrupt mode\n"); + } else { + dev_dbg(&client->dev, "Using polling mode\n"); + } indio_dev->info = &rfd77402_info; indio_dev->channels = rfd77402_channels; -- 2.43.0