From nobody Sat Feb 7 08:45:28 2026 Received: from mail.subdimension.ro (nalicastle.subdimension.ro [172.105.74.154]) (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 2C13C30F7E3; Wed, 10 Sep 2025 07:58:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=172.105.74.154 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757491094; cv=none; b=SiLVaMmJQmq8TLG5/IzPCtp/bxKADudshwjZ401M2uhnqVOlN7ulrV/gLTphD42qD7uqo3MmyCwLX3V+Yw1y1nJGg0MQcbcEqFgpI0rssKcOd5tbCn3sDg/TXdzi1FI8BO6rqRY0sPl9mnmajMtEaibIe63RUV6jm+/vq+Xuz7I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757491094; c=relaxed/simple; bh=1scJCB+806UtNfxHO3wDXIOqiSHVx3IrG0YVu0piZBk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=RcyNza9MWQVy6tDXe1LFxdr2cO6bFt3WTWoe8p48a4scSpGncVmNTnwDQK95DuegA5vDacgP1t/53x1xhDcw9cUkAdT6jY0aQy/GtQNgb4BnhI3SABirjTKq1S/gV29QjJkHc1Zb8JzIHsA/FMbsXEttr9pHBxTL42+dZzJTmpk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=subdimension.ro; spf=pass smtp.mailfrom=subdimension.ro; dkim=pass (2048-bit key) header.d=subdimension.ro header.i=@subdimension.ro header.b=g5XK6ZUL; arc=none smtp.client-ip=172.105.74.154 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=subdimension.ro Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=subdimension.ro Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=subdimension.ro header.i=@subdimension.ro header.b="g5XK6ZUL" Received: from [10.212.0.13] (unknown [IPv6:2a02:2f0e:3503:4a00:e2d5:5eff:fed9:f1c4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mail.subdimension.ro (Postfix) with ESMTPSA id 12611173BEF; Wed, 10 Sep 2025 10:58:04 +0300 (EEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=subdimension.ro; s=mail; t=1757491084; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AfJ3WGDj3DCbzW0qEw5j4fk1Oo5dl0J3mYsDlxO0xPM=; b=g5XK6ZULBWfMavS2bQ7oqpVH2NX2kidmhUIMqkUzaNQibg8chlHbW71tiowyFynOUhVeDA tM2U0lT2dUkiGnw6nbEnCEWYx+reMxnp6H7RMDpI5RhvYswabFJntO58UvitHyd3hZQ2OU Yl/wb5QQX8V6n2q8Udp++baKx7C9lzgyt6SmMW/esUL4pBlApaFbcFgWU3UzHmGt1HyrUW dIkEgKuG4DSAVyTdjlIk2CNSXX+WrBG4OxDRLZJw3w2DszJUc5Co3ZObEdBQIpizYnSi1Z C6Ymtd/xbLUYURDpMBVDQAwkCAa2by3ijE/lB8ttorkkiteTP+k1E0+4IGSSCQ== From: Petre Rodan Date: Wed, 10 Sep 2025 10:57:12 +0300 Subject: [PATCH v2 07/14] iio: accel: bma220: reset registers during init stage 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: <20250910-bma220_improvements-v2-7-e23f4f2b9745@subdimension.ro> References: <20250910-bma220_improvements-v2-0-e23f4f2b9745@subdimension.ro> In-Reply-To: <20250910-bma220_improvements-v2-0-e23f4f2b9745@subdimension.ro> To: Jonathan Cameron , David Lechner , =?utf-8?q?Nuno_S=C3=A1?= , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: Jonathan Cameron , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Petre Rodan X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=3680; i=petre.rodan@subdimension.ro; h=from:subject:message-id; bh=1scJCB+806UtNfxHO3wDXIOqiSHVx3IrG0YVu0piZBk=; b=owEBbQKS/ZANAwAIAc8mmZmETn8wAcsmYgBowS+H+lbBm1fJRNRUAbqlyfztjKh1lRU6RZSq2 JRxA60heJqJAjMEAAEIAB0WIQTYCn/BdhUZNew+X6nPJpmZhE5/MAUCaMEvhwAKCRDPJpmZhE5/ MOxmEAC+9O+71EeYTsLfT7dvbo3t7T3N74DOKhNgg+kC1FIwVWuzEIcB5whTkTYo3Jk8ASAQ6ds 9URirDv13cWoUT0XO/cg6wpjjA0dgUKKV59iULxlcvb5rIdc9IA+TZWHcFo9SpWt3e0aIsjIVRb AU2zKMXdgccGORaZSBTkLTcRB1sUs+1QP1A8Drox2Q5Sp45r+vubybEer65UsmZky37rlrYH0zX AdeHPRM66ffFAtChvG3rIYNcHoUzuzhkM36mfZrzuDzNxy+KZtjxk429kAyWF4dxV9Eby/eycgf J0n+zhkTtC0kbfyytr9S3BylW2zKQsW7hJBAajbGiYupbIW9winyB/ZiZGq5TVil01ILJHzl1eX 4MtODErwYCUoWrWsUpoUk9/bcLo2lww58+0y2NrDsVa/taZBGPKSvMoOfsjMoCBv4wqQ7dJHO7u A0JYN0UB8kOZLJKM8i9UjNrlFsf1EFcbkt4dkV20fb3X3reZ0cVTlgjBA2jz6plmKw7bXQGCG5J dGkWmJ1wdh8BCnBCne33PS3Vl6VlhhEPPoYzpNGw0z6J4ieLlupAGXg/X8p6jCSR3FCDTW1AI1i EDcxuWR7aNSB4ksNlq1rh+Fx9LRCgHEnGJSsD3JK7rP0cor7VlPo1Bx+0qQDJjtc+wGXEKKy7+B 3sTSgwPHpXIF4Fw== X-Developer-Key: i=petre.rodan@subdimension.ro; a=openpgp; fpr=D80A7FC176151935EC3E5FA9CF269999844E7F30 Bring all configuration registers to default values during device probe(). Signed-off-by: Petre Rodan --- drivers/iio/accel/bma220_core.c | 71 ++++++++++++++++++++++++++++---------= ---- 1 file changed, 49 insertions(+), 22 deletions(-) diff --git a/drivers/iio/accel/bma220_core.c b/drivers/iio/accel/bma220_cor= e.c index b6f1374a9cca52966c1055113710061a7284cf5a..322df516c90a7c645eeca579cae= 9803eb31caad1 100644 --- a/drivers/iio/accel/bma220_core.c +++ b/drivers/iio/accel/bma220_core.c @@ -29,12 +29,15 @@ #define BMA220_REG_ACCEL_Z 0x04 #define BMA220_REG_RANGE 0x11 #define BMA220_REG_SUSPEND 0x18 +#define BMA220_REG_SOFTRESET 0x19 =20 #define BMA220_CHIP_ID 0xDD #define BMA220_READ_MASK BIT(7) #define BMA220_RANGE_MASK GENMASK(1, 0) #define BMA220_SUSPEND_SLEEP 0xFF #define BMA220_SUSPEND_WAKE 0x00 +#define BMA220_RESET_MODE 0xFF +#define BMA220_NONRESET_MODE 0x00 =20 #define BMA220_DEVICE_NAME "bma220" =20 @@ -203,31 +206,28 @@ static const struct iio_info bma220_info =3D { .read_avail =3D bma220_read_avail, }; =20 -static int bma220_init(struct spi_device *spi) +static int bma220_reset(struct spi_device *spi, bool up) { - int ret; - static const char * const regulator_names[] =3D { "vddd", "vddio", "vdda"= }; + int i, ret; =20 - ret =3D devm_regulator_bulk_get_enable(&spi->dev, - ARRAY_SIZE(regulator_names), - regulator_names); - if (ret) - return dev_err_probe(&spi->dev, ret, "Failed to get regulators\n"); + /** + * The chip can be reset by a simple register read. + * We need up to 2 register reads of the softreset register + * to make sure that the device is in the desired state. + */ + for (i =3D 0; i < 2; i++) { + ret =3D bma220_read_reg(spi, BMA220_REG_SOFTRESET); + if (ret < 0) + return ret; =20 - ret =3D bma220_read_reg(spi, BMA220_REG_ID); - if (ret !=3D BMA220_CHIP_ID) - return -ENODEV; + if (up && (ret =3D=3D BMA220_RESET_MODE)) + return 0; =20 - /* Make sure the chip is powered on */ - ret =3D bma220_read_reg(spi, BMA220_REG_SUSPEND); - if (ret =3D=3D BMA220_SUSPEND_WAKE) - ret =3D bma220_read_reg(spi, BMA220_REG_SUSPEND); - if (ret < 0) - return ret; - if (ret =3D=3D BMA220_SUSPEND_WAKE) - return -EBUSY; + if (!up && (ret =3D=3D BMA220_NONRESET_MODE)) + return 0; + } =20 - return 0; + return -EBUSY; } =20 static int bma220_power(struct spi_device *spi, bool up) @@ -244,16 +244,43 @@ static int bma220_power(struct spi_device *spi, bool = up) if (ret < 0) return ret; =20 - if (up && ret =3D=3D BMA220_SUSPEND_SLEEP) + if (up && (ret =3D=3D BMA220_SUSPEND_SLEEP)) return 0; =20 - if (!up && ret =3D=3D BMA220_SUSPEND_WAKE) + if (!up && (ret =3D=3D BMA220_SUSPEND_WAKE)) return 0; } =20 return -EBUSY; } =20 +static int bma220_init(struct spi_device *spi) +{ + int ret; + static const char * const regulator_names[] =3D { "vddd", "vddio", "vdda"= }; + + ret =3D devm_regulator_bulk_get_enable(&spi->dev, + ARRAY_SIZE(regulator_names), + regulator_names); + if (ret) + return dev_err_probe(&spi->dev, ret, "Failed to get regulators\n"); + + ret =3D bma220_read_reg(spi, BMA220_REG_ID); + if (ret !=3D BMA220_CHIP_ID) + return -ENODEV; + + /* Make sure the chip is powered on and config registers are reset */ + ret =3D bma220_power(spi, true); + if (ret) + return dev_err_probe(&spi->dev, ret, "Failed to power-on chip\n"); + + ret =3D bma220_reset(spi, true); + if (ret) + return dev_err_probe(&spi->dev, ret, "Failed to soft reset chip\n"); + + return 0; +} + static void bma220_deinit(void *spi) { bma220_power(spi, false); --=20 2.49.1