From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marek Vasut <marex@denx.de>
Subject: Re: [PATCH] pwm: pxa: add device tree support to pwm driver
Date: Wed, 4 Sep 2013 16:35:26 +0200
Message-ID: <201309041635.26695.marex@denx.de>
References: <1378236233-15637-1-git-send-email-mikedunn@newsguy.com>
 <201309040020.55029.marex@denx.de> <5227425E.7030806@newsguy.com>
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To: Mike Dunn <mikedunn@newsguy.com>
Cc: linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, Rob Herring <rob.herring@calxeda.com>, Thierry Reding <thierry.reding@gmail.com>, Haojian Zhuang <haojian.zhuang@linaro.org>, Grant Likely <grant.likely@linaro.org>, Robert Jarzmik <robert.jarzmik@free.fr>, linux-arm-kernel@lists.infradead.org
List-Id: devicetree@vger.kernel.org

Dear Mike Dunn,

> On 09/03/2013 03:20 PM, Marek Vasut wrote:
> 
> [...]
> 
> >> +#ifdef CONFIG_OF
> >> +/* use the platform_device id table for OF match table data */
> >> +static struct of_device_id pwm_of_match[] = {
> >> +	{ .compatible = "marvell,pxa25x-pwm", .data = &pwm_id_table[0] },
> >> +	{ .compatible = "marvell,pxa27x-pwm", .data = &pwm_id_table[1] },
> >> +	{ .compatible = "marvell,pxa168-pwm", .data = &pwm_id_table[2] },
> >> +	{ .compatible = "marvell,pxa910-pwm", .data = &pwm_id_table[3] },
> >> +	{ }
> >> +};
> >> +MODULE_DEVICE_TABLE(of, pwm_of_match);
> > 
> > Are PXA2xx and PXA3xx PWM impleemntations not all the same ? If so, why
> > not just stick with pxa25x-pwm only for all of the CPUs (aka. the lowest
> > CPU model). Then the table would have but a single entry.
> 
> I'm just echoing the existing platform_device_id table...
> 
> static const struct platform_device_id pwm_id_table[] = {
> 	/*   PWM    has_secondary_pwm? */
> 	{ "pxa25x-pwm", 0 },
> 	{ "pxa27x-pwm", HAS_SECONDARY_PWM },
> 	{ "pxa168-pwm", 0 },
> 	{ "pxa910-pwm", 0 },
> 	{ },
> };
> MODULE_DEVICE_TABLE(platform, pwm_id_table);
> 
> ... so that my changes to the driver are minimal.  Yes, apparently the only
> difference is the existance of a "secondary" pwm for pxa27x.
> 
> BTW, the pxa27x actually has four pwms, which is why the addition I made to
> pxa27x.dtsi has two nodes (the driver handles two pwms for each device
> instance in the pxa27x case).
> 

What's that "secondary PWM" there? I no longer remember, sorry. The question 
remains still, we can have two entries there (pxa25x and pxa27x) ORR have one 
entry (pxa25x) + mrvl,has-secondary-pwm entry.

Best regards,
Marek Vasut