Date:	Sun, 23 Nov 2014 09:15:56 +0900
From:	Mattia Dongili <malattia@...ux.it>
To:	Alexander Gavrilenko <alexander.gavrilenko@...glemail.com>
Cc:	Alexander Gavrilenko <alexander.gavrilenko@...glemail.com>,
	platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
	Darren Hart <dvhart@...radead.org>
Subject: Re: [PATCH] sony-laptop: add support for Sony Vaio Fit multi-flip
 laptop/presentation/tablet transformation

On Fri, Nov 21, 2014 at 10:55:04AM -0800, Darren Hart wrote:
> On Thu, Nov 20, 2014 at 11:51:12AM +0300, Alexander Gavrilenko wrote:
> > Current mode is exported via sysfs:
> > /sys/devices/platform/sony-laptop/tablet
> > 
> 
> Merging with your reply and a few updates from me, you OK with:

I'll piggy-back on this merged mail for some other comments.

> 
>     sony-laptop: Support Sony Vaio Fit multi-flip tablet transformations
> 
>     Transformation events are sent through the ACPI bus as sony/hotkey
>     events. Tablet mode also triggers the SW_TABLET_MODE event via the
>     Sony Vaio Keys input device.
> 

could you send me (privately) the whole DSDT from a Vaio FIT? I think I
found one implementation, is it something like this?

	If (LEqual (Local0, 0x0E))
	{
	    And (Local1, 0x03, Local1)
	    If (LEqual (Local1, Zero))
	    {
		Store (One, ^^EC0.STEN)
		Return (Arg0)
	    }

	    If (LEqual (Local1, One))
	    {
		Store (Zero, ^^EC0.STEN)
		Return (Arg0)
	    }

	    If (LEqual (Local1, 0x02))
	    {
		Store (Zero, Local5)
		And (^^EC0.MDST, 0x03, Local5)
		Return (Local5)
	    }
	}


>     Current mode is exported via sysfs:
>     /sys/devices/platform/sony-laptop/tablet
> 
> It's important to keep the subject under 72 characters or so, or it
> gets truncated for a lot of git users.
> 
> > Signed-off-by: Alexander Gavrilenko <alexander.gavrilenko@...il.com>
> > ---
> > --- linux-3.17.3/drivers/platform/x86/sony-laptop.c.orig	2014-11-19 13:15:35.965048636 +0300
> > +++ linux-3.17.3/drivers/platform/x86/sony-laptop.c	2014-11-19 13:17:21.139166837 +0300
> > @@ -135,6 +135,13 @@ MODULE_PARM_DESC(kbd_backlight_timeout,
> >  		 "meaningful values vary from 0 to 3 and their meaning depends "
> >  		 "on the model (default: no change from current value)");
> >  
> > +static int tablet_mode = 2;
> > +module_param(tablet_mode, int, 0);
> > +MODULE_PARM_DESC(tablet_mode,
> > +		 "set this if your laptop have different tablet mode value, "
> 
> s/have/has a/
> 
> Generally speaking module params requied for normal usage a frowned upon.
> 
> This looks like something we should be able to detect by the HID or at worst the
> DMI strings. Maybe I'm missing something, why is this needed?

I'd agree this parameter is unnecessary at the moment. In many cases,
different implementations of the same functionality end up having a
different handle (0x16f in this case). You may be able to use different
values based on that.
Also, how many other tablet_mode values are known so far? If only "2" then
I wouldn't bother using this module parameter.

...
> > +		 "default is 2 (Sony Vaio Fit multi-flip), "
> > +		 "only affects SW_TABLET_MODE events");
> > +
> >  #ifdef CONFIG_PM_SLEEP
> >  static void sony_nc_thermal_resume(void);
> >  #endif
> > @@ -181,6 +188,11 @@ static int sony_nc_touchpad_setup(struct
> >  				  unsigned int handle);
> >  static void sony_nc_touchpad_cleanup(struct platform_device *pd);
> >  
> > +static int sony_nc_tablet_mode_setup(struct platform_device *pd,
> > +				  unsigned int handle);
> > +static void sony_nc_tablet_mode_cleanup(struct platform_device *pd);
> > +static int sony_nc_tablet_mode_update(void);
> > +
> >  enum sony_nc_rfkill {
> >  	SONY_WIFI,
> >  	SONY_BLUETOOTH,
> > @@ -1198,7 +1210,8 @@ static int sony_nc_hotkeys_decode(u32 ev
> >  enum event_types {
> >  	HOTKEY = 1,
> >  	KILLSWITCH,
> > -	GFX_SWITCH
> > +	GFX_SWITCH,
> > +	TABLET_MODE_SWITCH
> >  };
> >  static void sony_nc_notify(struct acpi_device *device, u32 event)
> >  {
> > @@ -1273,6 +1286,10 @@ static void sony_nc_notify(struct acpi_d
> >  			ev_type = GFX_SWITCH;
> >  			real_ev = __sony_nc_gfx_switch_status_get();
> >  			break;
> > +		case 0x016f:
> > +			ev_type = TABLET_MODE_SWITCH;
> > +			real_ev = sony_nc_tablet_mode_update();
> > +			break;
> >  		default:
> >  			dprintk("Unknown event 0x%x for handle 0x%x\n",
> >  					event, handle);
> > @@ -1428,6 +1445,13 @@ static void sony_nc_function_setup(struc
> >  				pr_err("couldn't set up smart connect support (%d)\n",
> >  						result);
> >  			break;
> > +		case 0x016f:
> > +			/* laptop/presentation/tablet transformation for Sony Vaio Fit 11a/13a/14a/15a */
> 
> The comment can wrap to meet line length guidelines.
> 
> > +			result = sony_nc_tablet_mode_setup(pf_device, handle);
> > +			if (result)
> > +				pr_err("couldn't set up tablet mode support (%d)\n",
> > +						result);
> > +			break;
> >  		default:
> >  			continue;
> >  		}
> > @@ -1507,6 +1531,9 @@ static void sony_nc_function_cleanup(str
> >  		case 0x0168:
> >  			sony_nc_smart_conn_cleanup(pd);
> >  			break;
> > +		case 0x016f:
> > +			sony_nc_tablet_mode_cleanup(pd);
> > +			break;
> >  		default:
> >  			continue;
> >  		}
> > @@ -1547,6 +1574,12 @@ static void sony_nc_function_resume(void
> >  		case 0x0135:
> >  			sony_nc_rfkill_update();
> >  			break;
> > +		case 0x016f:
> > +			/* re-enable transformation events */
> > +			sony_call_snc_handle(handle, 0, &result);
> > +			acpi_bus_generate_netlink_event(sony_nc_acpi_device->pnp.device_class,
> > +					dev_name(&sony_nc_acpi_device->dev), TABLET_MODE_SWITCH, sony_nc_tablet_mode_update());
> 
> Line length.
> 

I don't quite like the idea that the input event is generated in
sony_nc_tablet_mode_update() and the netlink event here.
Also, the event shouldn't trigger if there was no change in state.

> > +			break;
> >  		default:
> >  			continue;
> >  		}
> > @@ -3145,6 +3178,97 @@ static void sony_nc_backlight_cleanup(vo
> >  		backlight_device_unregister(sony_bl_props.dev);
> >  }
> >  
> > +/* laptop/presentation/tablet mode for Sony Vaio Fit 11a/13a/14a/15a */
> > +struct snc_tablet_control {
> > +	struct device_attribute attr;
> > +	int handle;
> > +	int mode;
> > +};
> > +static struct snc_tablet_control *tablet_ctl;
> > +
> > +static ssize_t sony_nc_tablet_mode_show(struct device *dev,
> > +					struct device_attribute *attr,
> > +					char *buffer)
> > +{
> > +	if(!tablet_ctl)
> > +		return -EIO;
> > +
> > +	return snprintf(buffer, PAGE_SIZE, "%d\n", tablet_ctl->mode);
> > +}
> > +
> > +static int sony_nc_tablet_mode_update(void) {
> > +	struct input_dev *key_dev = sony_laptop_input.key_dev;
> > +
> > +	if (!key_dev)
> > +		return -1;
> > +
> > +	if (!tablet_ctl)
> > +		return -1;
> 
> The above can be condensed:
> 
> if (!key_dev || !tablet_ctrl)
> 	return -1;
> 
> 
> 
> > +	if (sony_call_snc_handle(tablet_ctl->handle, 0x0200, &tablet_ctl->mode))
> > +		return -1;
> 
> Or even:
> 
> int ret = -1;
> if (key_dev && tablet_ctrl)
> 	ret = sony_call_snc...
> if (ret)
> 	return ret;

I'd call for better error codes than -1 as well.

> 
> > +	input_report_switch(key_dev, SW_TABLET_MODE, tablet_ctl->mode == tablet_mode);
> 
> Line length.
> 
> > +	input_sync(key_dev);
> > +
> > +	return tablet_ctl->mode;
> > +}
> > +
> > +static int sony_nc_tablet_mode_setup(struct platform_device *pd,
> > +					unsigned int handle)
> > +{
> > +	struct input_dev *key_dev = sony_laptop_input.key_dev;
> > +	int value, ret;
> 
> One variable per line please.
> 
> > +
> > +	if (tablet_ctl) {
> > +		pr_warn("handle 0x%.4x: laptop/presentation/tablet mode control setup already done for 0x%.4x\n",
> > +				handle, tablet_ctl->handle);
> > +		return -EBUSY;
> > +	}
> > +
> > +	if (sony_call_snc_handle(handle, 0x0000, &value))
> > +		return -EIO;

what does this call do? and 0x0100? and 0x0200? (I can sort figure but
there is enough black magic in this driver already)

> > +
> > +	tablet_ctl = kzalloc(sizeof(struct snc_tablet_control), GFP_KERNEL);
> > +	if (!tablet_ctl)
> > +		return -ENOMEM;
> > +
> > +	tablet_ctl->handle = handle;
> > +
> > +	sysfs_attr_init(&tablet_ctl->attr.attr);
> > +	tablet_ctl->attr.attr.name = "tablet";

call it "tablet_mode"?

> > +	tablet_ctl->attr.attr.mode = S_IRUGO;
> > +	tablet_ctl->attr.show = sony_nc_tablet_mode_show;
> > +	tablet_ctl->attr.store = NULL;
> 
> Please use the DEVICE_ATTR macros for setting these up, see other
> platform/driver/x86 drivers for examples.

It's quite common to do the manual initialization in this driver, I fail
to remember why it was done in the first place though... Possibly to be
able to allocate the structs as necessary, but I'm just speculating.

> > +
> > +	if (key_dev)
> > +		input_set_capability(key_dev, EV_SW, SW_TABLET_MODE);

why isn't this not done in sony_laptop_setup_input?

> > +	ret = device_create_file(&pd->dev, &tablet_ctl->attr);
> > +	if (ret)
> > +		goto tablet_error;
> > +	return 0;
> > +
> > +tablet_error:
> > +	device_remove_file(&pd->dev, &tablet_ctl->attr);
> > +	kfree(tablet_ctl);
> > +	tablet_ctl = NULL;
> > +	sony_call_snc_handle(handle, 0x0100, &value);
> > +	return ret;
> > +}
> > +
> > +static void sony_nc_tablet_mode_cleanup(struct platform_device *pd)
> > +{
> > +	int value;
> > +
> > +	if(tablet_ctl) {
> > +		device_remove_file(&pd->dev, &tablet_ctl->attr);
> > +		sony_call_snc_handle(tablet_ctl->handle, 0x0100, &value);
> > +		kfree(tablet_ctl);
> > +		tablet_ctl = NULL;
> > +	}
> > +}
> > +
> >  static int sony_nc_add(struct acpi_device *device)
> >  {
> >  	acpi_status status;
> > 
> 
> Thanks,

And thanks!
-- 
mattia
:wq!
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