From mboxrd@z Thu Jan 1 00:00:00 1970 From: thierry.reding@gmail.com (Thierry Reding) Date: Wed, 19 Jun 2013 00:20:00 +0200 Subject: [PATCH 08/15] pwm: Add new pwm-samsung driver In-Reply-To: <1834122.aETH5FyPtO@flatron> References: <1370467100-10820-1-git-send-email-tomasz.figa@gmail.com> <6439807.SaPozSx51p@flatron> <20130618214023.GB1926@mithrandir> <1834122.aETH5FyPtO@flatron> Message-ID: <20130618222000.GD1926@mithrandir> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jun 18, 2013 at 11:42:37PM +0200, Tomasz Figa wrote: > On Tuesday 18 of June 2013 23:40:23 Thierry Reding wrote: > > On Tue, Jun 18, 2013 at 09:41:09PM +0200, Tomasz Figa wrote: > > > On Monday 17 of June 2013 22:29:11 Thierry Reding wrote: > > > > On Wed, Jun 05, 2013 at 11:18:13PM +0200, Tomasz Figa wrote: > > [...] > > > > > > > +struct samsung_pwm_channel { > > > > > + unsigned long period_ns; > > > > > + unsigned long duty_ns; > > > > > + unsigned long tin_ns; > > > > > +}; > > > > > + > > > > > +struct samsung_pwm_chip { > > > > > + struct pwm_chip chip; > > > > > + struct samsung_pwm_variant variant; > > > > > + struct samsung_pwm_channel channels[SAMSUNG_PWM_NUM]; > > > > > > > > The new driver for Renesas did something similar, but I want to > > > > discourage storing per-channel data within the chip structure. > > > > > > > > The PWM framework provides a way to store this information along > > > > with > > > > the PWM device (see pwm_{set,get}_chip_data()). > > > > > > OK, this looks good, but in my case is not really useful. I need to > > > access those channel data in my suspend/resume callbacks and > > > obviously I don't have access to any pwm_device there. Any > > > suggestions? > > > > You do have access to the struct pwm_chip, and that already has an array > > of struct pwm_devices, so you could obtain the driver-specific data > > from those (see pwm_chip.pwms). > > Well, if it's legal to access internals of pwm_chip from PWM drivers then > there is no problem. Based on other subsystems, like regulators or clocks > I have concluded that this structure should be dereferenced only inside > PWM core. It's quite alright to do that. As a matter of fact you already do the same within the .probe() callback to set things up. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: not available URL: