From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Thu, 30 Jul 2015 14:05:17 -0600 Subject: [U-Boot] [PATCH 1/2] ARM: tegra: Add e2220-1170 board In-Reply-To: References: <1438199339-29329-1-git-send-email-swarren@wwwdotorg.org> <55BA6932.5060106@wwwdotorg.org> Message-ID: <55BA837D.6030102@wwwdotorg.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 07/30/2015 12:23 PM, Simon Glass wrote: > Hi Stephen, > > On 30 July 2015 at 12:13, Stephen Warren wrote: >> On 07/29/2015 05:02 PM, Simon Glass wrote: >>> >>> Hi Stephen, >>> >>> On 29 July 2015 at 13:48, Stephen Warren wrote: >>>> diff --git a/board/nvidia/e2220-1170/e2220-1170.c >>>> b/board/nvidia/e2220-1170/e2220-1170.c >> >>>> +void pin_mux_mmc(void) >>>> +{ >>>> + struct udevice *dev; >>>> + uchar val; >>>> + int ret; >>>> + >>>> + /* Turn on MAX77620 LDO2 to 3.3V for SD card power */ >>>> + ret = i2c_get_chip_for_busnum(0, 0x3c, 1, &dev); >>>> + if (ret) { >>>> + printf("%s: Cannot find MAX77620 I2C chip\n", __func__); >>>> + return; >>>> + } >>>> + val = 0xf2; >>>> + ret = dm_i2c_write(dev, 0x27, &val, 1); >>>> + if (ret) >>>> + printf("i2c_write 0 0x3c 0x27 failed: %d\n", ret); >>> >>> >>> Shouldn't this be in a PMIC driver? >> >> >> I think the overall amount of code contained in U-Boot ends up being a lot >> smaller this way; it simply and directly performs some necessary I2C writes, >> and V2 contains better comments describing the operation. This avoids all >> the overhead of creating a PMIC driver and instantiating it etc. This code >> is also consistent in style with many other Tegra boards. I'm rather >> inclined to leave this as-is unless there's some particular advantage you >> can state to creating a PMIC driver (I had thought of that original, but >> shied away from the large overhead/infrastructure involved with that.) > > If this is the only write that happens to the PMIC then that is fine. > But when you add other things, won't we need to adjust more things? I believe for the set of peripherals we're likely to support in U-Boot, this is enough. On the off-chance we add HDMI or USB3 host support, perhaps we'll need more regulators, but that's not something that's likely to happen soon.