From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794591311; b=R8N9omGUOTIgqwW9eP0N3MUwX3Pk7k/oeQBBDnMyD5+Ndlpru4Y9LAxkdytz+0/4tu/6 eYH/Z1EtkPbJ5tawMusyDcQNEwKeRGF7oCXLpIlyqAPL36dOLWtXFWM58GZWV9M5uz9sT TYjW+U6V6fp2cr1wILKbT9KLAngz6dHbLPGoa77N3Bu+d5cmj4pNmkYuhAjuF3Usq6yLK 85ruzkpJKiiusFbI8zm/vKE6w9I5KxBBE3klWrxAqN1GhHtnS9Tnc7M1UBMytOhhY3Oxz 0kysSoqC/mewMk73K1+O80QCG8LF/rqcofF1NXRWVkicPVjX7nozTu058OQKN8opS0g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794591311; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=OfZwTNkUbS1twRQNkkg3rGWowgs0afq5m4bi65ReSDE=; b=C8NeJ9A8FDZrWuFYCbooAFm97Hj4UXKnS2S4MJJXJmBwP6ZSHNaJmLnhxux6VgjyqkgS tIVfTXa4cshsQh4qxde0nw7Oo4all+jNo7L3y9IGx3BNVGqtEg1cx8Er+hRN3FzcyYNCb tIf9QCHbtJXNRTZxqNmI5LGSRzzOZYTphGL/eY5c4+TvJierDxqT7KaotE+coiyAXpGla 4F+bDdeTZpyXfbUBcCv72aU5x7GjRqhM86T3TYMYf6ETn5cUD1eP3tcb7gYn7yxGdb2y6 62ONojwMmSN2gHWGaIPS68aJE3RURyNPFECU43RRVIowULunaGJeSIYLQfJYXnPSUMQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=eKBtSePu; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4B17B606B213; Fri, 13 Nov 2026 17:35:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=eKBtSePu Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9BE1A1F000C5; Fri, 13 Nov 2026 17:35:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794591310; bh=OfZwTNkUbS1twRQNkkg3rGWowgs0afq5m4bi65ReSDE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eKBtSePuP7VYPhLmw6hn613Z+cp68DHU+apxf/T6DP92BywZ9TRnqluafJ3I4r0Yz pbGkg6+lCy6pbEuJgt6v3oDGDV+Mcou86QkpOkB5xheMXOG70EfHRy1P8+61IbZHFc mE/5YVUEZfjqCdpP5shI7Rp4jFNkA++UZoSK+7tc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jakub Szczudlo , Andy Shevchenko , Stable@vger.kernel.org, Jonathan Cameron , Sasha Levin Subject: [PATCH 6.12 423/670] iio: adc: ti-ads1100: Fix incorrect reading when datarate changed in single mode Date: Fri, 13 Nov 2026 10:49:47 -0500 Message-ID: <20261113153826.072351802@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153811.177190860@linuxfoundation.org> References: <20261113153811.177190860@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jakub Szczudlo [ Upstream commit 38dbf24dfbd0a73b89fa2871a7148429aef05531 ] When device is suspended and it is in single mode then changing datarate doesn't make it actually wait for new measurement, so to be sure that read after change is correct, functions that changes datarate and gain will wait for a new data. Fixes: 541880542f2b ("iio: adc: Add TI ADS1100 and ADS1000") Signed-off-by: Jakub Szczudlo Reviewed-by: Andy Shevchenko Cc: Signed-off-by: Jonathan Cameron [ sashal: replaced scoped PM guards with pm_runtime_resume_and_get() and explicit cleanup using pm_runtime_mark_last_busy() before pm_runtime_put_autosuspend() ] Signed-off-by: Sasha Levin --- drivers/iio/adc/ti-ads1100.c | 121 +++++++++++++++++++++++++++++++++-- 1 file changed, 115 insertions(+), 6 deletions(-) diff --git a/drivers/iio/adc/ti-ads1100.c b/drivers/iio/adc/ti-ads1100.c index 1e46f07a9ca6a..bea727ff9d6ee 100644 --- a/drivers/iio/adc/ti-ads1100.c +++ b/drivers/iio/adc/ti-ads1100.c @@ -14,10 +14,12 @@ #include #include #include +#include #include #include #include #include +#include #include #include @@ -42,6 +44,9 @@ static const int ads1100_data_rate[] = { 128, 32, 16, 8 }; static const int ads1100_data_rate_bits[] = { 12, 14, 15, 16 }; +/* Timeout based on the minimum sample rate of 8 SPS (7500ms) */ +#define ADS1100_MAX_DRDY_TIMEOUT_US (7500 * USEC_PER_MSEC) + struct ads1100_data { struct i2c_client *client; struct regulator *reg_vdd; @@ -123,10 +128,86 @@ static int ads1100_get_adc_result(struct ads1100_data *data, int chan, int *val) return 0; } +static int ads1100_conversion_busy(struct ads1100_data *data) +{ + u8 buffer[3]; + int ret; + + ret = i2c_master_recv(data->client, (char *)&buffer, sizeof(buffer)); + if (ret < 0) { + dev_err(&data->client->dev, "I2C read fail: %d\n", ret); + return ret; + } + + return FIELD_GET(ADS1100_CFG_ST_BSY, buffer[2]); +} + +static int ads1100_wait_single_conversion(struct ads1100_data *data) +{ + int data_rate_index = FIELD_GET(ADS1100_DR_MASK, data->config); + int data_rate_Hz = ads1100_data_rate[data_rate_index]; + unsigned long poll_us = DIV_ROUND_CLOSEST(USEC_PER_SEC, data_rate_Hz) / 4; + int busy; + int ret; + + ret = readx_poll_timeout(ads1100_conversion_busy, data, + busy, busy <= 0, + poll_us, ADS1100_MAX_DRDY_TIMEOUT_US); + if (busy < 0) + return busy; + + return ret; +} + +static int ads1100_start_single_conversion(struct ads1100_data *data) +{ + u8 config = data->config | ADS1100_CFG_SC; + int ret; + + ret = i2c_master_send(data->client, &config, sizeof(config)); + if (ret < 0) { + dev_err(&data->client->dev, "I2C write fail: %d\n", ret); + return ret; + } + /* Need to wait because of change from continuous to single mode */ + ret = ads1100_wait_single_conversion(data); + if (ret) + return ret; + + config |= ADS1100_CFG_ST_BSY; + + ret = i2c_master_send(data->client, &config, sizeof(config)); + if (ret < 0) { + dev_err(&data->client->dev, "I2C write fail: %d\n", ret); + return ret; + } + + /* No need to cache it, it's status bit */ + data->config = config & ~ADS1100_CFG_ST_BSY; + + return 0; +} + +static int ads1100_poll_data_ready(struct ads1100_data *data) +{ + int ret; + + ret = ads1100_start_single_conversion(data); + if (ret) + return ret; + + ret = ads1100_wait_single_conversion(data); + if (ret) + return ret; + + return ads1100_set_config_bits(data, ADS1100_CFG_SC, ADS1100_CONTINUOUS); +} + static int ads1100_set_scale(struct ads1100_data *data, int val, int val2) { int microvolts; int gain; + int ret; /* With Vdd between 2.7 and 5V, the scale is always below 1 */ if (val) @@ -135,6 +216,10 @@ static int ads1100_set_scale(struct ads1100_data *data, int val, int val2) if (!val2) return -EINVAL; + ret = pm_runtime_resume_and_get(&data->client->dev); + if (ret) + return ret; + microvolts = regulator_get_voltage(data->reg_vdd); /* * val2 is in 'micro' units, n = val2 / 1000000 @@ -144,27 +229,51 @@ static int ads1100_set_scale(struct ads1100_data *data, int val, int val2) * bitshift so everything fits in 32-bits yields this formula. */ gain = DIV_ROUND_CLOSEST(microvolts, BIT(15)) * MILLI / val2; - if (gain < BIT(0) || gain > BIT(3)) - return -EINVAL; + if (gain < BIT(0) || gain > BIT(3)) { + ret = -EINVAL; + goto out; + } ads1100_set_config_bits(data, ADS1100_PGA_MASK, ffs(gain) - 1); - return 0; + ret = ads1100_poll_data_ready(data); +out: + pm_runtime_mark_last_busy(&data->client->dev); + pm_runtime_put_autosuspend(&data->client->dev); + + return ret; } static int ads1100_set_data_rate(struct ads1100_data *data, int chan, int rate) { unsigned int i; unsigned int size; + int ret; size = data->supports_data_rate ? ARRAY_SIZE(ads1100_data_rate) : 1; for (i = 0; i < size; i++) { if (ads1100_data_rate[i] == rate) - return ads1100_set_config_bits(data, ADS1100_DR_MASK, - FIELD_PREP(ADS1100_DR_MASK, i)); + break; } - return -EINVAL; + if (i == size) + return -EINVAL; + + ret = pm_runtime_resume_and_get(&data->client->dev); + if (ret) + return ret; + + ret = ads1100_set_config_bits(data, ADS1100_DR_MASK, + FIELD_PREP(ADS1100_DR_MASK, i)); + if (ret) + goto out; + + ret = ads1100_poll_data_ready(data); +out: + pm_runtime_mark_last_busy(&data->client->dev); + pm_runtime_put_autosuspend(&data->client->dev); + + return ret; } static int ads1100_get_vdd_millivolts(struct ads1100_data *data) -- 2.53.0