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Date:   Wed, 01 Jun 2022 01:33:03 +0000
From:   Adam Wujek <dev_public@wujek.eu>
Cc:     Adam Wujek <dev_public@wujek.eu>,
        Guenter Roeck <linux@roeck-us.net>,
        Jean Delvare <jdelvare@suse.com>, linux-hwmon@vger.kernel.org,
        linux-kernel@vger.kernel.org
Reply-To: Adam Wujek <dev_public@wujek.eu>
Subject: [PATCH v3 1/2] hwmon: (pmbus) add a function to check the presence of a block register
Message-ID: <20220601013232.801133-1-dev_public@wujek.eu>
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Other functions (like pmbus_check_byte_register) cannot be used to check
the presence of a block register, because it will generate error when PEC
is used.

Signed-off-by: Adam Wujek <dev_public@wujek.eu>
---
Notes:
  Changes in v2:
    - Use Phase 0xff when setting the page
  Changes in v3:
    - remove not needed initialization of a buffer
    - add checking the flag PMBUS_READ_STATUS_AFTER_FAILED_CHECK

 drivers/hwmon/pmbus/pmbus_core.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_c=
ore.c
index acf78d0829d9..a1c70877ae68 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -421,6 +421,18 @@ static int _pmbus_read_byte_data(struct i2c_client *cl=
ient, int page, int reg)
 =09return pmbus_read_byte_data(client, page, reg);
 }

+static int pmbus_read_block_data(struct i2c_client *client, int page, u8 r=
eg,
+=09=09=09=09 char *data_buf)
+{
+=09int rv;
+
+=09rv =3D pmbus_set_page(client, page, 0xff);
+=09if (rv < 0)
+=09=09return rv;
+
+=09return i2c_smbus_read_block_data(client, reg, data_buf);
+}
+
 static struct pmbus_sensor *pmbus_find_sensor(struct pmbus_data *data, int=
 page,
 =09=09=09=09=09      int reg)
 {
@@ -558,6 +570,22 @@ bool pmbus_check_word_register(struct i2c_client *clie=
nt, int page, int reg)
 }
 EXPORT_SYMBOL_NS_GPL(pmbus_check_word_register, PMBUS);

+static bool pmbus_check_block_register(struct i2c_client *client, int page=
,
+=09=09=09=09       int reg)
+{
+=09int rv;
+=09struct pmbus_data *data =3D i2c_get_clientdata(client);
+=09char data_buf[I2C_SMBUS_BLOCK_MAX + 2];
+
+=09rv =3D pmbus_read_block_data(client, page, reg, data_buf);
+=09if (rv >=3D 0 && !(data->flags & PMBUS_SKIP_STATUS_CHECK))
+=09=09rv =3D pmbus_check_status_cml(client);
+=09if (rv < 0 && (data->flags & PMBUS_READ_STATUS_AFTER_FAILED_CHECK))
+=09=09data->read_status(client, -1);
+=09pmbus_clear_fault_page(client, -1);
+=09return rv >=3D 0;
+}
+
 const struct pmbus_driver_info *pmbus_get_driver_info(struct i2c_client *c=
lient)
 {
 =09struct pmbus_data *data =3D i2c_get_clientdata(client);
--
2.17.1