On Fri, May 07, 2021 at 08:14:20PM +0300, Vadim Pasternak wrote:
> Add support for mp2888 device from Monolithic Power Systems, Inc. (MPS)
> vendor. This is a digital, multi-phase, pulse-width modulation
> controller.
>
> This device supports:
> - One power rail.
> - Programmable Multi-Phase up to 10 Phases.
> - PWM-VID Interface
> - One pages 0 for telemetry.
> - Programmable pins for PMBus Address.
> - Built-In EEPROM to Store Custom Configurations.
> - Can configured VOUT readout in direct or VID format and allows
> setting of different formats on rails 1 and 2. For VID the following
> protocols are available: VR13 mode with 5-mV DAC; VR13 mode with
> 10-mV DAC, IMVP9 mode with 5-mV DAC.
>
> Signed-off-by: Vadim Pasternak <vadimp@xxxxxxxxxx>
> ---
> v5->v6
> Comments pointed out by Guenter:
> - Fix comments for limits in mp2888_read_word_data().
> - Remove unnecessary typecasts from mp2888_write_word_data().
>
> v4->v5
> Comments pointed out by Guenter:
> - Fix calculation of PMBUS_READ_VIN.
> - Add mp2888_write_word_data() for limits setting.
> - Treat PMBUS_POUT_OP_WARN_LIMIT in separate case.
> - Drop tuning of "m[PSC_POWER]" and "m[PSC_CURRENT_OUT]" from probing
> routine.
> Fixes from Vadim:
> - Treat PMBUS_IOUT_OC_WARN_LIMIT in separate case.
>
> v3->v4
> Comments pointed out by Guenter:
> - Fix PMBUS_READ_VIN and limits calculations.
> - Add comment for PMBUS_OT_WARN_LIMIT scaling.
> - Fix PMBUS_READ_IOUT, PMBUS_READ_POUT, PMBUS_READ_PIN calculations.
> - Enable PMBUS_IOUT_OC_WARN_LIMIT and PMBUS_POUT_OP_WARN_LIMIT.
> Fixes from Vadim:
> - Disable PMBUS_POUT_MAX. Device uses this register for different
> purpose.
> - Disable PMBUS_MFR_VOU_MIN. Device doe not implement this register.
> - Update documentation file.
>
> v2->v3
> Comments pointed out by Guenter:
> - Fix precision for PMBUS_READ_VIN (it requires adding scale for
> PMBUS_VIN_OV_FAULT_LIMIT and PMBUS_VIN_UV_WARN_LIMIT.
> - Fix precision for PMBUS_READ_TEMPERATURE_1 (it requires adding
> scale for PMBUS_OT_WARN_LIMIT).
> - Use DIV_ROUND_CLOSEST_ULL for scaling PMBUS_READ_POUT,
> PMBUS_READ_PIN readouts.
> Notes and fixes from Vadim:
> - READ_IOUT in linear11 does not give write calculation (tested with
> external load), while in direct format readouts are correct.
> - Disable non-configured phases in mp2888_identify_multiphase().
>
> v1->v2:
> Comments pointed out by Guenter:
> - Use standard access for getting PMBUS_OT_WARN_LIMIT,
> PMBUS_VIN_OV_FAULT_LIMIT, PMBUS_VIN_UV_WARN_LIMIT.
> - Use linear11 conversion for PMBUS_READ_VIN, PMBUS_READ_POUT,
> PMBUS_READ_PIN, PMBUS_READ_TEMPERATURE_1 and adjust coefficients.
> - Add reading phases current from the dedicated registers.
> - Add comment for not implemented or implemented not according to the
> spec registers, for which "ENXIO" code is returned.
> - Set PMBUS_HAVE_IOUT" statically.
> Notes from Vadim:
> - READ_IOUT uses direct format, so I did not adjust it like the below
> registers.
> ---
[ ... ]
> +
> +static int mp2888_write_word_data(struct i2c_client *client, int page, int reg, u16 word)
> +{
> + const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
> + struct mp2888_data *data = to_mp2888_data(info);
> +
> + switch (reg) {
> + case PMBUS_OT_WARN_LIMIT:
> + word = DIV_ROUND_CLOSEST((int)word, MP2888_TEMP_UNIT);
Sorry if I am missing something, but why those typecasts here and below ?
> + /* Drop unused bits 15:8. */
> + word = clamp_val(word, 0, GENMASK(7, 0));
> + break;
> + case PMBUS_IOUT_OC_WARN_LIMIT:
> + /* Fix limit according to total curent resolution. */
> + word = data->total_curr_resolution ? DIV_ROUND_CLOSEST((int)word, 8) :
> + DIV_ROUND_CLOSEST((int)word, 4);
> + /* Drop unused bits 15:10. */
> + word = clamp_val(word, 0, GENMASK(9, 0));
> + break;
> + case PMBUS_POUT_OP_WARN_LIMIT:
> + /* Fix limit according to total curent resolution. */
> + word = data->total_curr_resolution ? DIV_ROUND_CLOSEST((int)word, 4) :
> + DIV_ROUND_CLOSEST((int)word, 2);
> + /* Drop unused bits 15:10. */
> + word = clamp_val(word, 0, GENMASK(9, 0));
> + break;
> + default:
> + return -ENODATA;
> + }
> + return pmbus_write_word_data(client, page, reg, word);
> +}
> +
> +static int
> +mp2888_identify_multiphase(struct i2c_client *client, struct mp2888_data *data,
> + struct pmbus_driver_info *info)
> +{
> + int i, ret;
> +
> + ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
> + if (ret < 0)
> + return ret;
> +
> + /* Identify multiphase number - could be from 1 to 10. */
> + ret = i2c_smbus_read_word_data(client, MP2888_MFR_VR_CONFIG1);
> + if (ret <= 0)
> + return ret;
> +
> + info->phases[0] = ret & GENMASK(3, 0);
> +
> + /*
> + * The device provides a total of 10 PWM pins, and can be configured to different phase
> + * count applications for rail.
> + */
> + if (info->phases[0] > MP2888_MAX_PHASE)
> + return -EINVAL;
> +
> + /* Disable non-configured phases. */
> + for (i = info->phases[0]; i < MP2888_MAX_PHASE; i++)
> + info->pfunc[i] = 0;
Not that it matters much, but this is unnecessary since the pmbus core
won't look at phase data beyond info->phases[].
Guenter
