[U-Boot] [PATCH v2 1/3] arm: odroid: pmic77686: allow bucket voltage settings

[Suriyan Ramasami]

Hello Jaehoon Chung,


On Thu, Oct 23, 2014 at 11:52 PM, Jaehoon Chung <jh80.chung at samsung.com> wrote:
> Hi.
>
> On 10/21/2014 02:52 AM, Suriyan Ramasami wrote:
>> Allow to set the bucket voltage for the max77686.
>> This will be used to reset the SMC LAN9730 ethernet on the odroids.
>>
>> Signed-off-by: Suriyan Ramasami <suriyan.r at gmail.com>
>> ---
>>  drivers/power/pmic/pmic_max77686.c | 48 +++++++++++++++++++++++++++++++++++++-
>>  include/power/max77686_pmic.h      |  3 +++
>>  2 files changed, 50 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/power/pmic/pmic_max77686.c b/drivers/power/pmic/pmic_max77686.c
>> index df1fd91..1aeadb4 100644
>> --- a/drivers/power/pmic/pmic_max77686.c
>> +++ b/drivers/power/pmic/pmic_max77686.c
>> @@ -42,6 +42,25 @@ static unsigned int max77686_ldo_volt2hex(int ldo, ulong uV)
>>       return 0;
>>  }
>>
>> +static unsigned int max77686_buck_volt2hex(int buck, ulong uV)
>> +{
>> +     unsigned int hex = 0;
>> +
>> +     if (buck < 5 || buck > 9) {
>> +             debug("%s: buck %d is not supported\n", __func__, buck);
>> +             return 0;

Here, I should return MAX77686_BUCK_VOLT_MAX_HEX + 1 instead of 0 to
signal an error condition, as 0 is a valid non error value.

>> +     }
>> +
>> +     hex = (uV - 750000) / 50000;
>> +
>> +     if (hex >= 0 && hex <= MAX77686_BUCK_VOLT_MAX_HEX)
>> +             return hex;
>> +
>> +     debug("%s: %ld is wrong voltage value for BUCK%d\n",
>> +           __func__, uV, buck);
>> +     return MAX77686_BUCK_VOLT_MAX_HEX + 1;
>> +}
>> +
>>  int max77686_set_ldo_voltage(struct pmic *p, int ldo, ulong uV)
>>  {
>>       unsigned int val, ret, hex, adr;
>> @@ -68,6 +87,33 @@ int max77686_set_ldo_voltage(struct pmic *p, int ldo, ulong uV)
>>       return ret;
>>  }
>>
>> +int max77686_set_buck_voltage(struct pmic *p, int buck, ulong uV)
>> +{
>> +     unsigned int val, ret, hex, adr;
>> +
>> +     if (buck < 5 && buck > 9) {
>> +             printf("%s: %d is an unsupported bucket number\n",
>> +                    __func__, buck);
>> +             return -1;
>
> How about using error number instead of "-1"?

Could you please elaborate on this? This function always returns -1 on
failure just like the function max77686_set_ldo_voltate() which I have
tried to mimic as much as I can.
I am guessing that you want me to return -EINVAL in this case? Please
let me know, and I am OK to change it, just that this function will
deviate from the rest of the functions in this file.

>
>> +     }
>> +
>> +     adr = max77686_buck_addr[buck] + 1;
>> +     hex = max77686_buck_volt2hex(buck, uV);
>> +
>> +     if (hex == MAX77686_BUCK_VOLT_MAX_HEX + 1)
>> +             return -1;
>
> Ditto.

I believe, I return -EINVAL here, but please look at my reasoning above.

>
>> +
>> +     ret = pmic_reg_read(p, adr, &val);
>> +     if (ret)
>> +             return ret;
>> +
>> +     val &= ~MAX77686_BUCK_VOLT_MASK;
>> +     val |= hex;
>> +     ret |= pmic_reg_write(p, adr, val);
>
> ret |= pmic_reg_write(p, addr, val | hex); ?
>

OK, will change that. Again, this was done to be as close to
max77686_set_ldo_voltate()

Thanks and Regards!
- Suriyan

> Best Regards,
> Jaehoon Chung
>> +
>> +     return ret;
>> +}
>> +
>>  int max77686_set_ldo_mode(struct pmic *p, int ldo, char opmode)
>>  {
>>       unsigned int val, ret, adr, mode;
>> @@ -157,7 +203,7 @@ int max77686_set_buck_mode(struct pmic *p, int buck, char opmode)
>>       /* mode */
>>       switch (opmode) {
>>       case OPMODE_OFF:
>> -             mode = MAX77686_BUCK_MODE_OFF;
>> +             mode = MAX77686_BUCK_MODE_OFF << mode_shift;
>>               break;
>>       case OPMODE_STANDBY:
>>               switch (buck) {
>> diff --git a/include/power/max77686_pmic.h b/include/power/max77686_pmic.h
>> index c2a772a..b0e4255 100644
>> --- a/include/power/max77686_pmic.h
>> +++ b/include/power/max77686_pmic.h
>> @@ -150,6 +150,7 @@ enum {
>>
>>  int max77686_set_ldo_voltage(struct pmic *p, int ldo, ulong uV);
>>  int max77686_set_ldo_mode(struct pmic *p, int ldo, char opmode);
>> +int max77686_set_buck_voltage(struct pmic *p, int buck, ulong uV);
>>  int max77686_set_buck_mode(struct pmic *p, int buck, char opmode);
>>
>>  #define MAX77686_LDO_VOLT_MAX_HEX    0x3f
>> @@ -159,6 +160,8 @@ int max77686_set_buck_mode(struct pmic *p, int buck, char opmode);
>>  #define MAX77686_LDO_MODE_STANDBY    (0x01 << 0x06)
>>  #define MAX77686_LDO_MODE_LPM                (0x02 << 0x06)
>>  #define MAX77686_LDO_MODE_ON         (0x03 << 0x06)
>> +#define MAX77686_BUCK_VOLT_MAX_HEX   0x3f
>> +#define MAX77686_BUCK_VOLT_MASK              0x3f
>>  #define MAX77686_BUCK_MODE_MASK              0x03
>>  #define MAX77686_BUCK_MODE_SHIFT_1   0x00
>>  #define MAX77686_BUCK_MODE_SHIFT_2   0x04
>>
>