[PATCH 5.4 27/78] i2c: qcom-geni: Add shutdown callback for i2c

From: Greg Kroah-Hartman
Date: Tue Jun 08 2021 - 14:48:52 EST


From: Roja Rani Yarubandi <rojay@xxxxxxxxxxxxxx>

[ Upstream commit 9f78c607600ce4f2a952560de26534715236f612 ]

If the hardware is still accessing memory after SMMU translation
is disabled (as part of smmu shutdown callback), then the
IOVAs (I/O virtual address) which it was using will go on the bus
as the physical addresses which will result in unknown crashes
like NoC/interconnect errors.

So, implement shutdown callback for i2c driver to suspend the bus
during system "reboot" or "shutdown".

Fixes: 37692de5d523 ("i2c: i2c-qcom-geni: Add bus driver for the Qualcomm GENI I2C controller")
Signed-off-by: Roja Rani Yarubandi <rojay@xxxxxxxxxxxxxx>
Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-qcom-geni.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index b56a427fb928..d4ca00df6a5e 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -641,6 +641,14 @@ static int geni_i2c_remove(struct platform_device *pdev)
return 0;
}

+static void geni_i2c_shutdown(struct platform_device *pdev)
+{
+ struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);
+
+ /* Make client i2c transfers start failing */
+ i2c_mark_adapter_suspended(&gi2c->adap);
+}
+
static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
{
int ret;
@@ -701,6 +709,7 @@ MODULE_DEVICE_TABLE(of, geni_i2c_dt_match);
static struct platform_driver geni_i2c_driver = {
.probe = geni_i2c_probe,
.remove = geni_i2c_remove,
+ .shutdown = geni_i2c_shutdown,
.driver = {
.name = "geni_i2c",
.pm = &geni_i2c_pm_ops,
--
2.30.2