From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chen-Yu Tsai Subject: Re: [PATCH 05/11] mmc: sunxi: Support controllers that can use both old and new timings Date: Wed, 19 Jul 2017 16:59:23 +0800 Message-ID: References: <20170714064302.20383-1-wens@csie.org> <20170714064302.20383-6-wens@csie.org> <20170717091747.kcrlifbp7meihszm@flea> Reply-To: wens-jdAy2FN1RRM@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org In-Reply-To: <20170717091747.kcrlifbp7meihszm@flea> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Maxime Ripard Cc: Chen-Yu Tsai , Ulf Hansson , Michael Turquette , Stephen Boyd , Rob Herring , Mark Rutland , linux-arm-kernel , "linux-mmc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-clk , devicetree , linux-kernel , linux-sunxi List-Id: devicetree@vger.kernel.org On Mon, Jul 17, 2017 at 5:17 PM, Maxime Ripard wrote: > Hi, > > On Fri, Jul 14, 2017 at 02:42:56PM +0800, Chen-Yu Tsai wrote: >> On the SoCs that introduced the new timing mode for MMC controllers, >> both the old (where the clock delays are set in the CCU) and new >> (where the clock delays are set in the MMC controller) timing modes >> are available, and we have to support them both. However there are >> two bits that control which mode is active. One is in the CCU, the >> other is in the MMC controller. The settings on both sides must be >> the same, or nothing will work. >> >> The CCU's get/set_phase callbacks return -ENOTSUPP when the new >> timing mode is active. This provides a way to know which mode is >> active on that side, and we can set the bit on the MMC controller >> side accordingly. >> >> Signed-off-by: Chen-Yu Tsai >> --- >> drivers/mmc/host/sunxi-mmc.c | 34 ++++++++++++++++++++++++++++++---- >> 1 file changed, 30 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c >> index 0fb4e4c119e1..56e45c65b52d 100644 >> --- a/drivers/mmc/host/sunxi-mmc.c >> +++ b/drivers/mmc/host/sunxi-mmc.c >> @@ -22,6 +22,7 @@ >> #include >> >> #include >> +#include >> #include >> #include >> #include >> @@ -259,7 +260,7 @@ struct sunxi_mmc_cfg { >> /* Does DATA0 needs to be masked while the clock is updated */ >> bool mask_data0; >> >> - bool needs_new_timings; >> + bool has_new_timings; > > I think we should have both, it's a bit different. Newer SoCs like the > A64 can only operate using new timings, while the older ones can > operate in both modes. > > In one case, we're forced to use it, in the other one it's a > policy. We should differentiate both cases. For the A64's case, the limit is implied by not having any clk_delays. But yes, I'll keep "needs_new_timings", and rename the new option to "has_timing_switch" to make things clearer. ChenYu > > Looks good otherwise, thanks! > Maxime > > -- > Maxime Ripard, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com