(nuttx) branch master updated: drivers/ioexpander/iso1i813t.c: fix error startup condition

[linguini]

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linguini1 pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 69249fc9e61 drivers/ioexpander/iso1i813t.c: fix error startup condition
69249fc9e61 is described below

commit 69249fc9e61438b51201fbde62bbac42e014a784
Author: Michal Lenc <michall...@seznam.cz>
AuthorDate: Tue Jul 28 15:49:37 2026 +0200

    drivers/ioexpander/iso1i813t.c: fix error startup condition
    
    The reference manual (section 3.2.1) states the user has to
    read GLERR and INTERR registers to clear their bits and release
    ERR pin after the startup sequence. Error bits are set to 1 after
    the startup if external power supply is used.
    
    Not clearing the bits leads to subsequent read call errors if VBB
    errors are checked.
    
    Signed-off-by: Michal Lenc <michall...@seznam.cz>
---
 drivers/ioexpander/iso1i813t.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/ioexpander/iso1i813t.c b/drivers/ioexpander/iso1i813t.c
index 081403e4be0..26018a3e8db 100644
--- a/drivers/ioexpander/iso1i813t.c
+++ b/drivers/ioexpander/iso1i813t.c
@@ -511,6 +511,7 @@ FAR struct ioexpander_dev_s *iso1i813t_initialize(FAR 
struct spi_dev_s *spi,
                                       FAR struct iso1i813t_config_s *config)
 {
   FAR struct iso1i813t_dev_s *priv;
+  uint8_t txdata;
 
 #ifdef CONFIG_ISO1I813T_MULTIPLE
   /* Allocate the device state structure */
@@ -535,6 +536,21 @@ FAR struct ioexpander_dev_s *iso1i813t_initialize(FAR 
struct spi_dev_s *spi,
 
   nxmutex_init(&priv->lock);
 
+  /* Read GLERR and INTERR registers to clear their status bits
+   * and release ERR pin after the startup sequence. This is a required
+   * step if external power supply is used.
+   */
+
+  txdata = ISO1I813T_GLERR;
+  iso1i813t_select(priv->spi, priv->config, 8);
+  SPI_EXCHANGE(priv->spi, &txdata, NULL, 1);
+  iso1i813t_deselect(priv->spi, priv->config);
+
+  txdata = ISO1I813T_INTERR;
+  iso1i813t_select(priv->spi, priv->config, 8);
+  SPI_EXCHANGE(priv->spi, &txdata, NULL, 1);
+  iso1i813t_deselect(priv->spi, priv->config);
+
   return &priv->dev;
 }