diff mbox series

[v2,1/6] i2c: acpi: permit bus speed to be discovered after enumeration

Message ID 20190524162651.28189-2-ard.biesheuvel@linaro.org
State Accepted
Commit 4befedc045367c359de8ba021120fcf3bf797992
Headers show
Series crypto - wire up Atmel SHA204A as RNG in DT and ACPI mode | expand

Commit Message

Ard Biesheuvel May 24, 2019, 4:26 p.m. UTC 
Currently, the I2C ACPI enumeration code only permits the max bus rate
to be discovered before enumerating the slaves on the bus. In some
cases, drivers for slave devices may require this information, e.g.,
some ATmel crypto drivers need to generate a so-called wake token
of a fixed duration, regardless of the bus rate.

So tweak the code so i2c_acpi_lookup_speed() is able to obtain this
information after enumeration as well.

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

---
 drivers/i2c/i2c-core-acpi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

-- 
2.20.1
diff mbox series

Patch

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 272800692088..7240cc07abb4 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -115,8 +115,7 @@  static int i2c_acpi_do_lookup(struct acpi_device *adev,
 	struct list_head resource_list;
 	int ret;
 
-	if (acpi_bus_get_status(adev) || !adev->status.present ||
-	    acpi_device_enumerated(adev))
+	if (acpi_bus_get_status(adev) || !adev->status.present)
 		return -EINVAL;
 
 	if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
@@ -151,6 +150,9 @@  static int i2c_acpi_get_info(struct acpi_device *adev,
 	lookup.info = info;
 	lookup.index = -1;
 
+	if (acpi_device_enumerated(adev))
+		return -EINVAL;
+
 	ret = i2c_acpi_do_lookup(adev, &lookup);
 	if (ret)
 		return ret;