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| author | Jae Hyun Yoo <jae.hyun.yoo@intel.com> | 2019-03-08 02:17:40 +0300 |
|---|---|---|
| committer | Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> | 2021-11-05 10:22:07 +0300 |
| commit | c2e14a9df5334f7284bfa2b36408eb7d67628dd9 (patch) | |
| tree | 9b2b51331d6dfee189d464d23ae454a210ca8058 /drivers/i2c | |
| parent | 5652a04f2654d8b0c6883a254d01fbf22260e701 (diff) | |
| download | linux-c2e14a9df5334f7284bfa2b36408eb7d67628dd9.tar.xz | |
Add bus-timeout-ms and #retries device tree properties
BMC uses I2C bus 7 as a PMBus channel to communicate with PSUs,
also ME uses this bus as SMLink to control PSUs so this bus is
managed by multi-masters. In this use case, some arbitration errors
are expected so we need to add retry logic. And PMBus subsystem
uses I2C bus in kernel internally so retry logic should be
supported in kernel level.
To support the use case, this commit adds 'bus-timeout-ms' and
'#retries' device tree properties to set the bus specific
parameters at kernel boot time without using any additional ioctls
from user space.
This patch would not be accepted by I2C maintainer in linux
upstream because he doesn't like adding these legacy properties
into device tree, so keep it only in downstream.
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@intel.com>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-aspeed.c | 1 | ||||
| -rw-r--r-- | drivers/i2c/i2c-core-base.c | 12 |
2 files changed, 10 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index 3b9fd2cf3f9a..cd3509a4ff18 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -1044,7 +1044,6 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) spin_lock_init(&bus->lock); init_completion(&bus->cmd_complete); bus->adap.owner = THIS_MODULE; - bus->adap.retries = 0; bus->adap.algo = &aspeed_i2c_algo; bus->adap.dev.parent = &pdev->dev; bus->adap.dev.of_node = pdev->dev.of_node; diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 734834779d41..9eaf3f89aa7f 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1546,6 +1546,7 @@ static void i2c_adapter_unhold_work(struct work_struct *work) static int i2c_register_adapter(struct i2c_adapter *adap) { + u32 bus_timeout_ms = 0; int res = -EINVAL; /* Can't register until after driver model init */ @@ -1573,8 +1574,15 @@ static int i2c_register_adapter(struct i2c_adapter *adap) INIT_LIST_HEAD(&adap->userspace_clients); /* Set default timeout to 1 second if not already set */ - if (adap->timeout == 0) - adap->timeout = HZ; + if (adap->timeout == 0) { + device_property_read_u32(&adap->dev, "bus-timeout-ms", + &bus_timeout_ms); + adap->timeout = bus_timeout_ms ? + msecs_to_jiffies(bus_timeout_ms) : HZ; + } + + /* Set retries count if it has the property setting */ + device_property_read_u32(&adap->dev, "#retries", &adap->retries); /* register soft irqs for Host Notify */ res = i2c_setup_host_notify_irq_domain(adap); |