Re: [PATCH v8 4/4] Input: synaptics-rmi4 - add SMBus support
From: Benjamin Tissoires
Date: Fri Jun 24 2016 - 03:19:54 EST
On Jun 23 2016 or thereabouts, Dmitry Torokhov wrote:
> Hi Benjamin,
>
> On Thu, Jun 09, 2016 at 04:53:50PM +0200, Benjamin Tissoires wrote:
> > +
> > +struct mapping_table_entry {
> > + u16 rmiaddr;
>
> Should be __le16 rmiaddr, otherwise:
>
> CHECK drivers/input/rmi4/rmi_smbus.c
> drivers/input/rmi4/rmi_smbus.c:116:33: warning: incorrect type in assignment (different base types)
> drivers/input/rmi4/rmi_smbus.c:116:33: expected unsigned short [unsigned] [usertype] rmiaddr
> drivers/input/rmi4/rmi_smbus.c:116:33: got restricted __le16 [usertype] <noident>
>
> > +
> > +static struct i2c_driver rmi_smb_driver;
> > +
>
> I do not think this forward declaration is needed.
>
> > +
> > +#ifdef CONFIG_PM_SLEEP
> > +static int rmi_smb_suspend(struct device *dev)
>
> __maybe_unused instead of #ifdef.
>
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
> > + int ret;
> > +
> > + ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev);
> > + if (ret)
> > + dev_warn(dev, "Failed to suspend device: %d\n", ret);
> > +
> > + return ret;
> > +}
> > +#endif
> > +
> > +#ifdef CONFIG_PM
> > +static int rmi_smb_runtime_suspend(struct device *dev)
>
> Same here?
>
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
> > + int ret;
> > +
> > + ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev);
> > + if (ret)
> > + dev_warn(dev, "Failed to suspend device: %d\n", ret);
> > +
> > + return 0;
> > +}
> > +
> > +static int rmi_smb_runtime_resume(struct device *dev)
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
> > + int ret;
> > +
> > + ret = rmi_driver_resume(rmi_smb->xport.rmi_dev);
> > + if (ret)
> > + dev_warn(dev, "Failed to resume device: %d\n", ret);
> > +
> > + return 0;
> > +}
> > +#endif
> > +
> > +static const struct dev_pm_ops rmi_smb_pm = {
> > + SET_SYSTEM_SLEEP_PM_OPS(rmi_smb_suspend, NULL)
> > + SET_RUNTIME_PM_OPS(rmi_smb_runtime_suspend, rmi_smb_runtime_resume,
> > + NULL)
> > +};
> > +
> > +static int rmi_smb_resume(struct device *dev)
> > +{
> > + struct i2c_client *client = container_of(dev, struct i2c_client, dev);
> > + struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
> > + struct rmi_device *rmi_dev = rmi_smb->xport.rmi_dev;
> > + int ret;
> > +
> > + rmi_smb_reset(&rmi_smb->xport, 0);
> > +
> > + rmi_reset(rmi_dev);
> > +
> > + ret = rmi_driver_resume(rmi_smb->xport.rmi_dev);
> > + if (ret)
> > + dev_warn(dev, "Failed to resume device: %d\n", ret);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct i2c_device_id rmi_id[] = {
> > + { "rmi4_smbus", 0 },
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(i2c, rmi_id);
> > +
> > +static struct i2c_driver rmi_smb_driver = {
> > + .driver = {
> > + .owner = THIS_MODULE,
> > + .name = "rmi4_smbus",
> > + .pm = &rmi_smb_pm,
> > + .resume = rmi_smb_resume,
>
> Why rmi_smb_resume is not part of rmi_smb_pm?
>
This is because rmi_smbus device both have a PS/2 interface and a SMBus
one. I'll have to check again now that I have a slightly different way
of binding smbus devices in my tree, but the issue was:
- having resume part of pm means it will get caught by PM directly
- the PS/2 node gets also resumed by PM
- calling PS/2 commands during resume switches the devices back into
PS/2 and stops the SMBus communication.
So it's easier to wait only for the PS/2 PM resume call which will call
the SMBus resume function when the device is in a proper state.
I'll send out the updated patch with your comments next week hopefully.
Cheers,
Benjamin