diff options
| author | Jisheng Zhang <jszhang@marvell.com> | 2014-07-25 11:57:46 (GMT) |
|---|---|---|
| committer | Matthew Weigel <Matthew.Weigel@freescale.com> | 2014-12-11 18:38:51 (GMT) |
| commit | 9d6673a9b828c23ae39d8c5b66022f6d4ba135f2 (patch) | |
| tree | d5202bc10e0e741a12aa335c81206dd95d45dc20 /drivers/i2c | |
| parent | 211f21a752cd81324528d33700f17cadc89b31d1 (diff) | |
| download | linux-fsl-qoriq-9d6673a9b828c23ae39d8c5b66022f6d4ba135f2.tar.xz | |
i2c: pca954x: put the mux to disconnected state after resume
pca954x may be power lost during suspend, so after resume we also suffer
the issue fixed by commit cd823db8b1161ef0d756514d280715a576d65cc3,
"pca954x power-on default is channel 0 connected. If multiple pca954x
muxes are connected to the same physical I2C bus, the parent bus will
see channel 0 devices behind both muxes by default."
What's more, when resume bootloader may also operate the mux, so the
the channel connected after that may not be the one driver thought.
We fix this problem by putting the mux to disconnected state and
clearing last_chan in the resume hook.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
--
Cherry-pickded from linux.git:
f5e596cd9f0ec6c03660fe4196d395bc3da919a4
Change-Id: I43da37cf2f854e023f5ff645d20134b919347142
Reviewed-on: http://git.am.freescale.net:8181/21929
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Zhengxiong Jin <Jason.Jin@freescale.com>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/muxes/i2c-mux-pca954x.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c index bad5b84..687ecb3 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -41,6 +41,7 @@ #include <linux/device.h> #include <linux/i2c.h> #include <linux/i2c-mux.h> +#include <linux/pm.h> #include <linux/i2c/pca954x.h> @@ -274,9 +275,23 @@ static int pca954x_remove(struct i2c_client *client) return 0; } +#ifdef CONFIG_PM_SLEEP +static int pca954x_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct pca954x *data = i2c_get_clientdata(client); + + data->last_chan = 0; + return i2c_smbus_write_byte(client, 0); +} +#endif + +static SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume); + static struct i2c_driver pca954x_driver = { .driver = { .name = "pca954x", + .pm = &pca954x_pm, .owner = THIS_MODULE, }, .probe = pca954x_probe, |