From mboxrd@z Thu Jan 1 00:00:00 1970 From: balbi@ti.com (Felipe Balbi) Date: Thu, 2 Feb 2012 23:53:51 +0200 Subject: [PATCH v9 01/25] gpio/omap: remove dependency on gpio_bank_count In-Reply-To: <20120202214907.GA22888@legolas.emea.dhcp.ti.com> References: <1328203851-20435-1-git-send-email-tarun.kanti@ti.com> <1328203851-20435-2-git-send-email-tarun.kanti@ti.com> <20120202184106.GC29215@legolas.emea.dhcp.ti.com> <20120202191630.GT15343@ponder.secretlab.ca> <20120202194545.GA29351@legolas.emea.dhcp.ti.com> <4F2AF68D.1000505@ti.com> <20120202214907.GA22888@legolas.emea.dhcp.ti.com> Message-ID: <20120202215350.GB22888@legolas.emea.dhcp.ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi again, On Thu, Feb 02, 2012 at 11:49:08PM +0200, Felipe Balbi wrote: > > In fact the driver already handled the 6 GPIOS banks as individual devices: > > > > [ 0.185638] gpiochip_add: registered GPIOs 0 to 31 on device: gpio > > [ 0.185882] OMAP GPIO hardware version 0.1 > > [ 0.186767] gpiochip_add: registered GPIOs 32 to 63 on device: gpio > > [ 0.187744] gpiochip_add: registered GPIOs 64 to 95 on device: gpio > > [ 0.188751] gpiochip_add: registered GPIOs 96 to 127 on device: gpio > > [ 0.189819] gpiochip_add: registered GPIOs 128 to 159 on device: gpio > > [ 0.190917] gpiochip_add: registered GPIOs 160 to 191 on device: gpio > > yeah, but you can get all of that for free from driver core. Just add > one platform_device for each bank and make the omap-gpio.c only > understand one bank. No tricks. > > What I'm trying to say is to remove the Bank array or list_head and make > probe() get called 6 times by creating 6 omap_gpio platform_devices. > > From probe you cann gpiochip_add() once and only once. ^^^^ call I actually just took the time to go over the driver and that's what it does. So the list_head is only there fo the nasty cpuidle stuff below: > > That list is only used to iterate over all the instances during CPU idle: > > > > void omap2_gpio_prepare_for_idle(int pwr_mode) > > { > > struct gpio_bank *bank; > > > > list_for_each_entry(bank, &omap_gpio_list, node) { > > if (!bank->mod_usage || !bank->loses_context) > > continue; > > > > bank->power_mode = pwr_mode; > > > > pm_runtime_put_sync_suspend(bank->dev); > > } > > } > > > > void omap2_gpio_resume_after_idle(void) > > { > > struct gpio_bank *bank; > > > > list_for_each_entry(bank, &omap_gpio_list, node) { > > if (!bank->mod_usage || !bank->loses_context) > > continue; > > > > pm_runtime_get_sync(bank->dev); > > } > > } > > that's the thing which is unnecessary, actually :-) > > Why do we even have this omap2_gpio_resume_after_idle() ? Can't the gpio > driver handle its own PM or listen to cpuidle notificaitons for that ? > > I would like to understand why do we need this hack for pm runtime. > Can't you just use ->prepare() and ->complete() from dev_pm_ops ? This question remains. Why do we need those funtions ? -- balbi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: