From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: Re: [PATCH v3 35/36] platform/x86: intel_pmc_ipc: Convert to MFD
Date: Mon, 20 Jan 2020 11:26:50 +0200
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To: Lee Jones <lee.jones@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Darren Hart <dvhart@infradead.org>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>, x86@kernel.org, Zha Qipeng <qipeng.zha@intel.com>, "David E . Box" <david.e.box@linux.intel.com>, Guenter Roeck <linux@roeck-us.net>, Heikki Krogerus <heikki.krogerus@linux.intel.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Wim Van Sebroeck <wim@linux-watchdog.org>, platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org
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On Fri, Jan 17, 2020 at 11:32:02AM +0000, Lee Jones wrote:
> [...]
> 
> > > Looks like Regmap could save you the trouble here.
> > 
> > Agreed.
> 
> Great.

I started to implement regmap for this driver but I run into some
problems. The registers we read/write are all 64-bit and accessed trough
readq/writeq accessors. However, the regmap API takes unsigned int:

  int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
  int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);

I'm not sure how we can take advantage of this API with the 64-bit
registers. There are "raw" versions of the functions that take void
pointer like:

 int regmap_raw_read(struct regmap *map, unsigned int reg,
                     void *val, size_t val_len);

but looking at the implementation if the register gets cached it
internally does reads in unsigned int sized chunks (if I understand it
right).

Any ideas how this can be done?

Thanks!