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=1794062706; b=Bw+1jzrAOxttoHPuanXs4+Hl73shDxytb4pg4S+DLEFLDSssA68WENJGK+hJmyTGohY2 E8knhMiGQQuYCs0FKzoHWNkRGVEetM5F7YulUTo7yoC5RVGzlTTZQl1lsKr0todZTXqvQ lz6eFWba8XnQPGGLcp26W8Pn1vUWGQtT7k1pp2JyqN6X3+oxdlvO5IwTk5G4E8S60y9m/ q0t+Wj9RmCqWdCVLRZOLzfh3XfPXROaMf8QzZWqgo3svQCTNd+qwWHYIMRuyeuL3xUqVj 61e/CDYgFiKSs5/pC6zQMU4IUIAyMqFvUMr2CUUCnaonTb1UP4dBpLM+WDUXsdcfM/Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794062706; 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=AMC+vMU5cO6z2nWP5qu3asP9bmq88bbVcWp54E3Qk/o=; b=WKsw3ZekdWoMoAUHIdDf8FoNY1DIH2sG1SSpQ9S17CbGOwCzwRtQwqZ97WE3UOrfQDOF MxKYF9KodJgjiIV4EiRmlhDNKFu+DjkY5WkTrHz92fuN1ixH7WXnfgSaloIEo07KSkqHp VKRDIKiuJlh9C3LSmsAdLmFgyST1D06f9qXc8stj4ceSjlfqOXbcwpdEjyogpQbg6ax69 357c9lfEsIdlCaL/1CHX3maIVDopggRAsn7eKZzdCFW3L49Jq2G0rDA9tLtakourCJvb9 D69jGGSKlnvCzZ8RQz2TzEp74XXZyslAVmM4ijSWNCjF/VTCuck1qKrwzdo+GS2UOxg== 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=p0V4y9WV; 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 3AB39606A32D; Sat, 7 Nov 2026 14:45:06 +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=p0V4y9WV Received: by smtp.kernel.org (Postfix) with ESMTPSA id D980B1F008A1; Sat, 7 Nov 2026 14:45:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794062706; bh=AMC+vMU5cO6z2nWP5qu3asP9bmq88bbVcWp54E3Qk/o=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=p0V4y9WVhLaxX9BaA2yllinPgVhsXy+S/LBMTOUnDPPDmeAiZEHAvCJ71kUjYtsmN WGHPI+h9wuLZkbax+0tFWTp1WfhVxWdPmmZp3QuQrkc2RPXGdb6YNmWRoYIOHw3H0F PUE0NaVctq+T+wneonxN1yViHYtYa48jpbHStQ4M= 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 6.18 029/869] iio: adc: ti-ads1100: Fix incorrect reading when datarate changed in single mode Date: Sat, 7 Nov 2026 08:45:11 -0500 Message-ID: <20261107134853.121585822@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@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 6.18-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 Signed-off-by: Sasha Levin --- drivers/iio/adc/ti-ads1100.c | 107 +++++++++++++++++++++++++++++++++-- 1 file changed, 103 insertions(+), 4 deletions(-) diff --git a/drivers/iio/adc/ti-ads1100.c b/drivers/iio/adc/ti-ads1100.c index aa8946063c7d6..5c08bed48018c 100644 --- a/drivers/iio/adc/ti-ads1100.c +++ b/drivers/iio/adc/ti-ads1100.c @@ -15,10 +15,12 @@ #include #include #include +#include #include #include #include #include +#include #include #include @@ -43,6 +45,9 @@ 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 +216,11 @@ static int ads1100_set_scale(struct ads1100_data *data, int val, int val2) if (!val2) return -EINVAL; + PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(&data->client->dev, pm); + ret = PM_RUNTIME_ACQUIRE_ERR(&pm); + if (ret) + return ret; + microvolts = regulator_get_voltage(data->reg_vdd); /* * val2 is in 'micro' units, n = val2 / 1000000 @@ -149,22 +235,35 @@ static int ads1100_set_scale(struct ads1100_data *data, int val, int val2) ads1100_set_config_bits(data, ADS1100_PGA_MASK, ffs(gain) - 1); - return 0; + return ads1100_poll_data_ready(data); } 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; + + PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(&data->client->dev, pm); + ret = PM_RUNTIME_ACQUIRE_ERR(&pm); + if (ret) + return ret; + + ret = ads1100_set_config_bits(data, ADS1100_DR_MASK, + FIELD_PREP(ADS1100_DR_MASK, i)); + if (ret) + return ret; + + return ads1100_poll_data_ready(data); } static int ads1100_get_vdd_millivolts(struct ads1100_data *data) -- 2.53.0