[U-Boot] [PATCH V3 6/6] T210: Add support for 64-bit T210-based P2571 board

[Tom Warren]

> -----Original Message-----
> From: Stephen Warren [mailto:swarren at wwwdotorg.org]
> Sent: Tuesday, July 28, 2015 12:27 PM
> To: Tom Warren
> Cc: u-boot at lists.denx.de; Thierry Reding; Stephen Warren;
> tomcwarren3959 at gmail.com
> Subject: Re: [U-Boot] [PATCH V3 6/6] T210: Add support for 64-bit T210-based
> P2571 board
> 
> On 07/24/2015 04:01 PM, Tom Warren wrote:
> > Based on Venice2, incorporates Stephen Warren's latest P2571 pinmux
> > table.
> >
> > With Thierry Reding's 64-bit build fixes, this will build and and boot
> > in 64-bit on my P2571 (when used with a 32-bit AVP loader).
> 
> > diff --git a/board/nvidia/p2571/max77620_init.c
> > b/board/nvidia/p2571/max77620_init.c
> 
> > +void pmic_enable_cpu_vdd(void)
> 
> This function is never called, or even linked into the binary. For previous Tegra
> SoCs, it was called from the SPL before booting the CCPLEX. Since there is no
> SPL for Tegra210, nothing calls this.
> 
> > +	debug("%s: Set LDO2 for VDDIO_SDMMC_AP power to 3.3V\n",
> __func__);
> > +	/* 0xF2 for 3.3v, enabled: bit7:6 = 11 = enable, bit5:0 = voltage */
> > +	reg = 0xF200 | MAX77620_CNFG1_L2_REG;
> > +	tegra_i2c_ll_write_addr(MAX77620_I2C_ADDR, 2);
> > +	tegra_i2c_ll_write_data(reg, I2C_SEND_2_BYTES);
> > +	udelay(10 * 1000);
> 
> This explains why the SD card isn't working for me on p2371-2180; I guess the
> PMIC OTP on that board has this regulator disabled, and since this code never
> runs, it never gets turned on. If I manually turn it on using the i2c command,
> then "mmc dev 1" works.
Makes sense. My initial development was on a 32-bit build (32-bit AVP SPL + 32-bit U-Boot CPU), so this was called from the AVP code. I still use this 32-bit AVP SPL 'portion' to load my 64-bit CPU binary, so LDO2 does get inited.  Your flow is with a different AVP 32-bit 'loader', so some PMIC rails aren't set.

> 
> For p2571, I think we should either delete this file entirely. Or, at least strip it
> down so that it's not touching global PMIC configuration but rather just
> enabling any non-CCPLEX rails that U-Boot might need such as SD card and USB,
> then rename the function and arrange for it to be called from somewhere. I'm
> not sure what a good name and call-site would be yet.
Sounds reasonable. I'll look into rewriting this and calling it in the CPU binary, unless you get to it first.

Tom

--
nvpublic