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From: Henning Schild <henning.schild@siemens.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>,
	Jean Delvare <jdelvare@suse.de>, Lee Jones <lee.jones@linaro.org>,
	Tan Jui Nee <jui.nee.tan@intel.com>,
	Jim Quinlan <james.quinlan@broadcom.com>,
	"Jonathan Yong" <jonathan.yong@intel.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	<linux-kernel@vger.kernel.org>, <linux-i2c@vger.kernel.org>,
	<linux-pci@vger.kernel.org>, Jean Delvare <jdelvare@suse.com>,
	Peter Tyser <ptyser@xes-inc.com>, <hdegoede@redhat.com>
Subject: Re: [PATCH v1 6/7] mfd: lpc_ich: Add support for pinctrl in non-ACPI system
Date: Mon, 12 Apr 2021 19:27:14 +0200
Message-ID: <20210412192714.617d18b0@md1za8fc.ad001.siemens.net> (raw)
In-Reply-To: <YHR6njWCHn77v7lQ@smile.fi.intel.com>

Am Mon, 12 Apr 2021 19:51:42 +0300
schrieb Andy Shevchenko <andriy.shevchenko@linux.intel.com>:

> On Mon, Apr 12, 2021 at 06:01:06PM +0200, Henning Schild wrote:
> > Am Mon, 8 Mar 2021 14:20:19 +0200
> > schrieb Andy Shevchenko <andriy.shevchenko@linux.intel.com>:
> >   
> > > From: Tan Jui Nee <jui.nee.tan@intel.com>
> > > 
> > > Add support for non-ACPI systems, such as system that uses
> > > Advanced Boot Loader (ABL) whereby a platform device has to be
> > > created in order to bind with pin control and GPIO.
> > > 
> > > At the moment, Intel Apollo Lake In-Vehicle Infotainment (IVI)
> > > system requires a driver to hide and unhide P2SB to lookup P2SB
> > > BAR and pass the PCI BAR address to GPIO.  
> 
> ...
> 
> > > +/* Offset data for Apollo Lake GPIO controllers */
> > > +#define APL_GPIO_SOUTHWEST_OFFSET	0xc00000
> > > +#define APL_GPIO_SOUTHWEST_SIZE		0x654
> > > +#define APL_GPIO_NORTHWEST_OFFSET	0xc40000
> > > +#define APL_GPIO_NORTHWEST_SIZE		0x764
> > > +#define APL_GPIO_NORTH_OFFSET		0xc50000
> > > +#define APL_GPIO_NORTH_SIZE		0x76c  
> > 
> > drivers/pinctrl/intel/pinctrl-broxton.c:653
> > BXT_COMMUNITY(0, 77),
> >   
> > > +#define APL_GPIO_WEST_OFFSET		0xc70000
> > > +#define APL_GPIO_WEST_SIZE		0x674  
> > 
> > All these sizes correlate with 4 magic numbers from pinctrl-broxton.
> > 
> > SIZE - 0x500 (pad_base?) - 4 (no clue) / 8
> > 
> > It might be worth basing both numbers on a define and giving the
> > magic numbers some names.  
> 
> I didn't get this, sorry. The numbers above just precise sizes of the
> resources. Actually they all one page anyway, so, I can drop magic of
> SIZEs and leave only offsets.

That precise size is also in the broxton driver, i think. Say we did
have

#define BXT_NORTH_COUNT 77
#define PAD_BASE 0x500

in some central place

then we could use

size = 0x500 + 8 * BXT_NORTH_COUNT + 4 (no clue what that is)

the same pattern would work for all those sizes and their
BXT_COMMUNITY(0, XX) counterparts

So the real size seems to be a function of the magic numbers in
BXT_COMMUNITY(0, XX)

Or simply take one page as you say.

> > But all this seems like duplication of pinctrl-broxton, maybe the
> > pinctrl driver should unhide the p2sb ...  
> 
> Definitely should not. It's not a business of the pin control driver
> to know how it has to be instantiated (or from what data). These
> offsets belong to the platform description and since firmware hides
> the device without given an appropriate ACPI device node, we have
> only one choice (assuming firmware is carved in stone) -- board files.
> 
> P2SB on the other hand is a slice of many (independent) devices.
> There is no "proper" place to unhide it except some core part of x86
> / PCI.

Got it, still the fact that there are 4 regions/communities is also part
of the broxton driver so there is duplication.

regards,
Henning


  reply index

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-08 12:20 [rfc, PATCH v1 0/7] PCI: introduce p2sb helper Andy Shevchenko
2021-03-08 12:20 ` [PATCH v1 1/7] PCI: Introduce pci_bus_*() printing macros when device is not available Andy Shevchenko
2021-03-10 14:57   ` Jean Delvare
2021-03-08 12:20 ` [PATCH v1 2/7] PCI: Convert __pci_read_base() to __pci_bus_read_base() Andy Shevchenko
2021-03-10 17:14   ` Christoph Hellwig
2021-03-08 12:20 ` [PATCH v1 3/7] PCI: New Primary to Sideband (P2SB) bridge support library Andy Shevchenko
2021-03-08 18:52   ` Bjorn Helgaas
2021-03-08 19:16     ` Andy Shevchenko
2021-03-09  1:42       ` Bjorn Helgaas
2021-03-09  8:42         ` Henning Schild
2021-04-02 13:09           ` Enrico Weigelt, metux IT consult
2021-04-06 13:40             ` Henning Schild
2021-03-13  9:45   ` Henning Schild
2021-04-01 15:43     ` Andy Shevchenko
2021-04-01 18:06       ` Mika Westerberg
2021-04-01 18:22         ` Andy Shevchenko
2021-04-01 18:32           ` Mika Westerberg
2021-03-08 12:20 ` [PATCH v1 4/7] mfd: lpc_ich: Factor out lpc_ich_enable_spi_write() Andy Shevchenko
2021-03-10 10:29   ` Lee Jones
2021-03-08 12:20 ` [PATCH v1 5/7] mfd: lpc_ich: Switch to generic pci_p2sb_bar() Andy Shevchenko
2021-03-10 10:35   ` Lee Jones
2021-03-10 12:05     ` Andy Shevchenko
2021-03-10 12:57       ` Lee Jones
2021-03-08 12:20 ` [PATCH v1 6/7] mfd: lpc_ich: Add support for pinctrl in non-ACPI system Andy Shevchenko
2021-03-10 10:27   ` Lee Jones
2021-04-12 16:01   ` Henning Schild
2021-04-12 16:40     ` Henning Schild
2021-04-12 16:59       ` Andy Shevchenko
2021-04-12 17:16         ` Henning Schild
2021-04-12 17:34           ` Andy Shevchenko
2021-04-13  6:47             ` Henning Schild
2021-04-12 16:51     ` Andy Shevchenko
2021-04-12 17:27       ` Henning Schild [this message]
2021-04-12 17:41         ` Andy Shevchenko
2021-03-08 12:20 ` [PATCH v1 7/7] i2c: i801: convert to use common P2SB accessor Andy Shevchenko
2021-03-10 14:51   ` Jean Delvare
2021-03-13  9:25 ` [rfc, PATCH v1 0/7] PCI: introduce p2sb helper Henning Schild
2021-06-10  9:02 ` Henning Schild
2021-06-10 10:14   ` Andy Shevchenko
2021-06-10 13:48     ` Henning Schild
2021-06-10 14:04       ` Andy Shevchenko
2021-04-01 15:45 [PATCH v1 3/7] PCI: New Primary to Sideband (P2SB) bridge support library Andy Shevchenko
2021-04-01 16:42 ` Bjorn Helgaas
2021-04-01 18:23   ` Andy Shevchenko
2021-04-01 18:44     ` Bjorn Helgaas

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