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

[Stephen Warren]

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...