From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Glass Date: Tue, 18 Apr 2017 08:33:06 -0600 Subject: [U-Boot] [PATCH v1] mmc: sdhci: SDHCI controllers also need power In-Reply-To: <1492525775.24567.69.camel@linux.intel.com> References: <20170315182521.4359-1-andriy.shevchenko@linux.intel.com> <1490014266.19767.101.camel@linux.intel.com> <1491052273.708.95.camel@linux.intel.com> <1354bacc-4ad5-91c4-c3d1-0b28cdf09617@samsung.com> <1491471989.24567.19.camel@linux.intel.com> <1492525775.24567.69.camel@linux.intel.com> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Andy, On 18 April 2017 at 08:29, Andy Shevchenko wrote: > On Fri, 2017-04-07 at 19:05 +0900, Jaehoon Chung wrote: >> Hi Andy, >> >> On 04/06/2017 07:58 PM, Andy Shevchenko wrote: >> > On Thu, Apr 6, 2017 at 1:50 PM, Jaehoon Chung > > m> wrote: >> > > On 04/06/2017 06:46 PM, Andy Shevchenko wrote: >> > > > On Thu, 2017-04-06 at 18:24 +0900, Jaehoon Chung wrote: >> > > > > On 04/06/2017 05:51 PM, Andy Shevchenko wrote: >> > > > > > On Thu, Apr 6, 2017 at 6:44 AM, Simon Glass > > > > > > g> >> > > > > > wrote: >> > > > > > > On 1 April 2017 at 07:11, Andy Shevchenko >> > > > > > > wrote: >> > > > > how about mmc_power_init() is called in mmc_probe()? >> > > > >> > > > Yes, that's what I'm referring to. But the driver is pure SDHCI, >> > > > it >> > > > doesn't call mmc_probe() IIRC. >> > > >> > > After converting to DM, it might have the dependent to probing >> > > sequence. >> > > I'm not sure that u-boot has the priority for probing. maybe >> > > not... >> > > >> > > hmm..need to consider this patch..but i will think about more >> > > generic solution.. >> > >> > It would be nice to have a generic solution indeed. >> >> Just thinking about below..? >> >> vcc_sd: sdmmc-regulator { >> ... >> regulator-boot-on; >> or >> regulator-always-on; >> ... >> >> }; >> >> It should be always enabled.. > > Sorry, but no. It's not a regulator. > > If you would like to know details, the 2 bits in PMU registers basically > represent clock gate and reset signal per IP which PMU controls. > > P.S. Hardware might have a common regulator per power island which is > automatically latches the power down if all devices on the island are on > D3hot. But it's not controlled by software. You have a few options: - Add a regulator/pmic driver for the PMU - Add a reset driver to handle the reset and perhaps a clock driver to handle the clock gate, then handle this in your driver You can subclass sdhci.c and adjust it as you need it. > > So, please consider my initial approach. We should use DM rather than custom hooks. If this doesn't make sense please let me know how I can help expound on it. > > This patch holds Edison enabling... Then let's get it figured out! > > -- > Andy Shevchenko > Intel Finland Oy Regards, Simon