From: Hans de Goede <hdegoede@redhat.com>
To: "Rafael J . Wysocki" <rjw@rjwysocki.net>,
Len Brown <lenb@kernel.org>, Darren Hart <dvhart@infradead.org>,
Andy Shevchenko <andy@infradead.org>,
Jonathan Cameron <jic23@kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>,
linux-acpi@vger.kernel.org, platform-driver-x86@vger.kernel.org,
linux-kernel@vger.kernel.org, Hartmut Knaack <knaack.h@gmx.de>,
Lars-Peter Clausen <lars@metafoo.de>,
Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
linux-iio@vger.kernel.org
Subject: [PATCH v3 06/11] iio: light: cm32181: Handle CM3218 ACPI devices with 2 I2C resources
Date: Tue, 28 Apr 2020 19:29:18 +0200 [thread overview]
Message-ID: <20200428172923.567806-6-hdegoede@redhat.com> (raw)
In-Reply-To: <20200428172923.567806-1-hdegoede@redhat.com>
Some ACPI systems list 2 I2C resources for the CM3218 sensor. On these
systems the first I2cSerialBus ACPI-resource points to the SMBus Alert
Response Address (ARA, 0x0c) and the second I2cSerialBus ACPI-resource
points to the actual CM3218 sensor address:
Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings
{
Name (SBUF, ResourceTemplate ()
{
I2cSerialBusV2 (0x000C, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.I2C3",
0x00, ResourceConsumer, , Exclusive,
)
I2cSerialBusV2 (0x0048, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.I2C3",
0x00, ResourceConsumer, , Exclusive,
)
Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive, ,, )
{
0x00000033,
}
})
Return (SBUF) /* \_SB_.I2C3.ALSD._CRS.SBUF */
}
Detect this and take the following step to deal with it:
1. When a SMBus Alert capable sensor has an Alert asserted, it will
not respond on its actual I2C address. Read a byte from the ARA
to clear any pending Alerts.
2. Create a "dummy" client for the actual I2C address and
use that client to communicate with the sensor.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v3:
- Create and use a dummy client instead of relying on i2c-multi-instantiate
to create 2 separate clients for the 2 I2C resources
Changes in v2
- s/i2c_client-s/I2C clients/ in added comment
---
drivers/iio/light/cm32181.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
index 8fe49610fc26..c23a5c3a86a3 100644
--- a/drivers/iio/light/cm32181.c
+++ b/drivers/iio/light/cm32181.c
@@ -51,6 +51,8 @@
#define CM32181_CALIBSCALE_RESOLUTION 1000
#define MLUX_PER_LUX 1000
+#define SMBUS_ALERT_RESPONSE_ADDRESS 0x0c
+
static const u8 cm32181_reg[CM32181_CONF_REG_NUM] = {
CM32181_REG_ADDR_CMD,
};
@@ -335,6 +337,26 @@ static int cm32181_probe(struct i2c_client *client)
if (!indio_dev)
return -ENOMEM;
+ /*
+ * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the
+ * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address.
+ * Detect this and take the following step to deal with it:
+ * 1. When a SMBus Alert capable sensor has an Alert asserted, it will
+ * not respond on its actual I2C address. Read a byte from the ARA
+ * to clear any pending Alerts.
+ * 2. Create a "dummy" client for the actual I2C address and
+ * use that client to communicate with the sensor.
+ */
+ if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) {
+ struct i2c_board_info board_info = { .type = "dummy" };
+
+ i2c_smbus_read_byte(client);
+
+ client = i2c_acpi_new_device(dev, 1, &board_info);
+ if (IS_ERR(client))
+ return PTR_ERR(client);
+ }
+
cm32181 = iio_priv(indio_dev);
cm32181->client = client;
--
2.26.0
next prev parent reply other threads:[~2020-04-28 17:29 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 17:29 [PATCH v3 01/11] iio: light: cm32181: Switch to new style i2c-driver probe function Hans de Goede
2020-04-28 17:29 ` [PATCH v3 02/11] iio: light: cm32181: Add support for ACPI enumeration Hans de Goede
2020-04-28 17:29 ` [PATCH v3 03/11] iio: light: cm32181: Add some extra register defines Hans de Goede
2020-04-28 17:29 ` [PATCH v3 04/11] iio: light: cm32181: Add support for the CM3218 Hans de Goede
2020-05-03 10:59 ` Jonathan Cameron
2020-05-04 9:49 ` Hans de Goede
2020-05-04 10:23 ` Jonathan Cameron
2020-04-28 17:29 ` [PATCH v3 05/11] iio: light: cm32181: Clean up the probe function a bit Hans de Goede
2020-05-03 11:00 ` Jonathan Cameron
2020-04-28 17:29 ` Hans de Goede [this message]
2020-05-03 11:04 ` [PATCH v3 06/11] iio: light: cm32181: Handle CM3218 ACPI devices with 2 I2C resources Jonathan Cameron
2020-05-04 9:52 ` Hans de Goede
2020-04-28 17:29 ` [PATCH v3 07/11] iio: light: cm32181: Change reg_init to use a bitmap of which registers to init Hans de Goede
2020-04-28 17:29 ` [PATCH v3 08/11] iio: light: cm32181: Use units of 1/100000th for calibscale and lux_per_bit Hans de Goede
2020-04-28 17:29 ` [PATCH v3 09/11] iio: light: cm32181: Make lux_per_bit and lux_per_bit_base_it runtime settings Hans de Goede
2020-04-28 17:29 ` [PATCH v3 10/11] iio: light: cm32181: Add support for parsing CPM0 and CPM1 ACPI tables Hans de Goede
2020-05-03 11:22 ` Jonathan Cameron
2020-05-03 16:25 ` Andy Shevchenko
2020-05-04 9:40 ` Jonathan Cameron
2020-05-04 9:57 ` Hans de Goede
2020-04-28 17:29 ` [PATCH v3 11/11] iio: light: cm32181: Fix integartion time typo Hans de Goede
2020-05-03 10:54 ` [PATCH v3 01/11] iio: light: cm32181: Switch to new style i2c-driver probe function Jonathan Cameron
2020-05-04 9:46 ` Hans de Goede
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200428172923.567806-6-hdegoede@redhat.com \
--to=hdegoede@redhat.com \
--cc=andy@infradead.org \
--cc=dvhart@infradead.org \
--cc=jic23@kernel.org \
--cc=knaack.h@gmx.de \
--cc=lars@metafoo.de \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-iio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=platform-driver-x86@vger.kernel.org \
--cc=pmeerw@pmeerw.net \
--cc=rjw@rjwysocki.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).