[U-Boot] [PATCH 6/7] ARM: tegra: enable SD card on p2771-0000

[Simon Glass]

Hi Stephen,

On 1 August 2016 at 10:02, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 07/31/2016 07:04 PM, Simon Glass wrote:
>>
>> Hi Stephen,
>>
>> On 29 July 2016 at 13:15, Stephen Warren <swarren at wwwdotorg.org> wrote:
>>>
>>> From: Stephen Warren <swarren at nvidia.com>
>>>
>>> Now that clock and reset drivers exist for Tegra186, we can enable the SD
>>> card controller. Now that a BPMP I2C driver exists for Tegra186, we can
>>> communicate with the PMIC to enable power to the SD card. Hook up the DT
>>> content and board code required to make the SD card work.
>
>
>>> diff --git a/board/nvidia/p2771-0000/p2771-0000.c
>>> b/board/nvidia/p2771-0000/p2771-0000.c
>
>
>>> +int tegra_board_init(void)
>>> +{
>>> +       struct udevice *dev;
>>> +       uchar val;
>>> +       int ret;
>>> +
>>> +       /* Turn on MAX77620 LDO3 to 3.3V for SD card power */
>>> +       debug("%s: Set LDO3 for VDDIO_SDMMC_AP power to 3.3V\n",
>>> __func__);
>>> +       ret = i2c_get_chip_for_busnum(0, MAX77620_I2C_ADDR_7BIT, 1,
>>> &dev);
>>> +       if (ret) {
>>> +               printf("%s: Cannot find MAX77620 I2C chip\n", __func__);
>>> +               return ret;
>>> +       }
>>> +       /* 0xF2 for 3.3v, enabled: bit7:6 = 11 = enable, bit5:0 = voltage
>>> */
>>> +       val = 0xF2;
>>> +       ret = dm_i2c_write(dev, MAX77620_CNFG1_L3_REG, &val, 1);
>>> +       if (ret) {
>>> +               printf("i2c_write 0 0x3c 0x27 failed: %d\n", ret);
>>> +               return ret;
>>> +       }
>>
>>
>> Can you add a simple pmic driver for this? It's really easy and avoids
>> the horrible busnum stuff. The i2c_get_chip_for_busnum() should
>> ideally not be used.
>
>
> Perhaps we can defer that until later?
>
> FWIW, this current approach is used by all/most Tegra boards and works great
> for now. If converting this kind of code to use the PMIC infra-structure,
> I'd rather take a pass and do all Tegra boards at once, but equally I'd
> rather not hold up the Tegra186 patches behind yet another common API
> conversion; there are already 3 new common APIs introduced for Tegra in the
> Tegra186 support...

OK, will I remember this coming up previously, so I look forward to it
getting sorted out. It really isn't that much work to write a PMIC
driver.

Regards,
Simon