"Varadarajan, Charulatha" <charu@xxxxxx> writes: >> -----Original Message----- >> From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx] >> Sent: Wednesday, April 07, 2010 4:01 AM >> To: Varadarajan, Charulatha >> Cc: linux-omap@xxxxxxxxxxxxxxx; Nayak, Rajendra; paul@xxxxxxxxx; tony@xxxxxxxxxxx >> Subject: Re: [PATCH 0/8 RFC] OMAP: GPIO: Split OMAP1 and OMAP2PLUS >> >> Charulatha V <charu@xxxxxx> writes: >> >> > This patch series is in preparation to adapt GPIO to HWMOD FW. >> > It creates OMAP architecture specific gpio files to handle >> > SoC specific gpio_init. The common plat-omap/gpio.c handles all >> > common GPIO APIs. >> > >> > OMAP2PLUS GPIO module is implemented as early platform device and >> > OMAP1 GPIO is still handled in old way via gpio_init from board files. >> > >> > Save/restore context, gpio_prepare_for_retention and >> > gpio_resume_after_retention APIs are also handled in plat-omap layer. >> > These APIs are currently not used in OMAP1, but still they might >> > become common for different OMAP architectures in the future. >> > Hence they are handled in plat-omap layer. If they need to be moved >> > to mach-omap2 layer, additional patches may be sent during >> > next version of this patch series. >> > >> > This patch series is generated on top of linux-omap-2.6 branch: master >> > and tested on 3430SDP, 4430SDP & zoom3. >> >> I have many problems with this series, but without going into the >> specifics of each patch, I have a big problem with the general >> approach being taken here. >> >> You say this is in preparation for adaptation to hwmod, but in fact, >> this series is duplicating a lot of the work you would get for free by >> starting with hwmod. >> >> You're generating a bunch of code that will be completely thrown away >> with a hwmod conversion. Instead, you should *start* by using hwmod + >> omap_device to generate the platform_devices for you. Doing this, you >> will drop patches 2, 3 and 4 entirely (they are mostly identical >> anyways, except for the search-and-replace) and also eliminate the >> need for patch 5. >> >> What is needed here is a way to introduce the platform_device >> conversion without introducing signifcant functional changes at the >> same time. Here's a proposal to do that, and which should also be >> considerably easier to review for sanity: >> >> - use hwmod + omap_device to generate (early) platform_devices >> - modify plat-omap/gpio.c to use base addr and IRQ from platform_device >> - modify plat-omap/gpio.c to get clocks based on 'struct device' >> >> For an example, you can see the pm-wip/hwmods branch in my tree for >> how this was done for UART and the pm-wip/mmc branch for how this was >> done for MMC. > > I agree that most of the code would be thrown away once HWMOD comes into picture. Since hwmod patches would be gated for a long time, we decided to first proceed in pushing "GPIO as early init" patch series to mainline first, so that hwmods branch and mainline would not differ much. > > Tony/Kevin, > > Please suggest which approach is better > 1. to send early init GPIO patches to mainline due to above mentioned reason (or) > 2. to make GPIO as a HWMOD FW adapted driver and gate it in hwmods branch. Please do option 2 to avoid massive duplication of work. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
