From cc2c3540d9477a9931fb0fd851fcaeba524a5b35 Mon Sep 17 00:00:00 2001 From: Sam Winchenbach <swinchenbach@arka.org> Date: Mon, 3 Feb 2025 13:34:34 +0000 Subject: [PATCH] iio: filter: admv8818: Force initialization of SDO When a weak pull-up is present on the SDO line, regmap_update_bits fails to write both the SOFTRESET and SDOACTIVE bits because it incorrectly reads them as already set. Since the soft reset disables the SDO line, performing a read-modify-write operation on ADI_SPI_CONFIG_A to enable the SDO line doesn't make sense. This change directly writes to the register instead of using regmap_update_bits. Fixes: f34fe888ad05 ("iio:filter:admv8818: add support for ADMV8818") Signed-off-by: Sam Winchenbach <swinchenbach@arka.org> Link: https://patch.msgid.link/SA1P110MB106904C961B0F3FAFFED74C0BCF5A@SA1P110MB1069.NAMP110.PROD.OUTLOOK.COM Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> --- drivers/iio/filter/admv8818.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/drivers/iio/filter/admv8818.c b/drivers/iio/filter/admv8818.c index 848baa6e3bbf5..d85b7d3de8660 100644 --- a/drivers/iio/filter/admv8818.c +++ b/drivers/iio/filter/admv8818.c @@ -574,21 +574,15 @@ static int admv8818_init(struct admv8818_state *st) struct spi_device *spi = st->spi; unsigned int chip_id; - ret = regmap_update_bits(st->regmap, ADMV8818_REG_SPI_CONFIG_A, - ADMV8818_SOFTRESET_N_MSK | - ADMV8818_SOFTRESET_MSK, - FIELD_PREP(ADMV8818_SOFTRESET_N_MSK, 1) | - FIELD_PREP(ADMV8818_SOFTRESET_MSK, 1)); + ret = regmap_write(st->regmap, ADMV8818_REG_SPI_CONFIG_A, + ADMV8818_SOFTRESET_N_MSK | ADMV8818_SOFTRESET_MSK); if (ret) { dev_err(&spi->dev, "ADMV8818 Soft Reset failed.\n"); return ret; } - ret = regmap_update_bits(st->regmap, ADMV8818_REG_SPI_CONFIG_A, - ADMV8818_SDOACTIVE_N_MSK | - ADMV8818_SDOACTIVE_MSK, - FIELD_PREP(ADMV8818_SDOACTIVE_N_MSK, 1) | - FIELD_PREP(ADMV8818_SDOACTIVE_MSK, 1)); + ret = regmap_write(st->regmap, ADMV8818_REG_SPI_CONFIG_A, + ADMV8818_SDOACTIVE_N_MSK | ADMV8818_SDOACTIVE_MSK); if (ret) { dev_err(&spi->dev, "ADMV8818 SDO Enable failed.\n"); return ret; -- GitLab