mfd: max597x: Add support for MAX5970 and MAX5978

Implement a regulator driver with IRQ support for fault management.
Written against documentation [1] and [2] and tested on real hardware.

Every channel has it's own regulator supply nammed 'vss1-supply' and
'vss2-supply'. The regulator supply is used to determine the output
voltage, as the smart switch provides no output regulation.
The driver requires the 'shunt-resistor-micro-ohms' to be present in
the devicetree to properly calculate current related values.

You must specify compatible devictree layout:

regulator@3a {
        reg = <0x3a>;
        vss1-supply = <&p3v3>;
        compatible = "maxim,max5978";

        ...

        regulators {
                sw0_ref: SW0 {
                        regulator-compatible = "SW0";
                        shunt-resistor-micro-ohms = <12000>;
                        ...
                }
        }
}

1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf

...
Changes in V12:
- Use simple_mfd_i2c driver and remove previous implementation.
- Remove newline
- Use _MFD_MAX597X_H in header file
- Successfull build need following patch from regulator:
https://lore.kernel.org/r/20230216075302.68935-1-Naresh.Solanki@9elements.com
https://lore.kernel.org/r/20230210163225.1208035-1-Naresh.Solanki@9elements.com

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230307121246.127425-2-Naresh.Solanki@9elements.com
This commit is contained in:
Patrick Rudolph 2023-03-07 13:12:45 +01:00 committed by Lee Jones
parent ba2b13df8a
commit 0742c2a633
3 changed files with 119 additions and 0 deletions

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@ -266,6 +266,16 @@ config MFD_MADERA_SPI
Support for the Cirrus Logic Madera platform audio SoC
core functionality controlled via SPI.
config MFD_MAX597X
tristate "Maxim 597x power switch and monitor"
depends on (I2C && OF)
select MFD_SIMPLE_MFD_I2C
help
This driver controls a Maxim 5970/5978 switch via I2C bus.
The MAX5970/5978 is a smart switch with no output regulation, but
fault protection and voltage and current monitoring capabilities.
Also it supports upto 4 indication leds.
config MFD_CS47L15
bool "Cirrus Logic CS47L15"
select PINCTRL_CS47L15

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@ -72,9 +72,22 @@ static const struct simple_mfd_data silergy_sy7636a = {
.mfd_cell_size = ARRAY_SIZE(sy7636a_cells),
};
static const struct mfd_cell max597x_cells[] = {
{ .name = "max597x-regulator", },
{ .name = "max597x-iio", },
{ .name = "max597x-led", },
};
static const struct simple_mfd_data maxim_max597x = {
.mfd_cell = max597x_cells,
.mfd_cell_size = ARRAY_SIZE(max597x_cells),
};
static const struct of_device_id simple_mfd_i2c_of_match[] = {
{ .compatible = "kontron,sl28cpld" },
{ .compatible = "silergy,sy7636a", .data = &silergy_sy7636a},
{ .compatible = "maxim,max5970", .data = &maxim_max597x},
{ .compatible = "maxim,max5978", .data = &maxim_max597x},
{}
};
MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);

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@ -0,0 +1,96 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Device driver for regulators in MAX5970 and MAX5978 IC
*
* Copyright (c) 2022 9elements GmbH
*
* Author: Patrick Rudolph <patrick.rudolph@9elements.com>
*/
#ifndef _MFD_MAX597X_H
#define _MFD_MAX597X_H
#include <linux/regmap.h>
#define MAX5970_NUM_SWITCHES 2
#define MAX5978_NUM_SWITCHES 1
#define MAX597X_NUM_LEDS 4
struct max597x_data {
int num_switches;
u32 irng[MAX5970_NUM_SWITCHES];
u32 mon_rng[MAX5970_NUM_SWITCHES];
u32 shunt_micro_ohms[MAX5970_NUM_SWITCHES];
};
enum max597x_chip_type {
MAX597x_TYPE_MAX5978 = 1,
MAX597x_TYPE_MAX5970,
};
#define MAX5970_REG_CURRENT_L(ch) (0x01 + (ch) * 4)
#define MAX5970_REG_CURRENT_H(ch) (0x00 + (ch) * 4)
#define MAX5970_REG_VOLTAGE_L(ch) (0x03 + (ch) * 4)
#define MAX5970_REG_VOLTAGE_H(ch) (0x02 + (ch) * 4)
#define MAX5970_REG_MON_RANGE 0x18
#define MAX5970_MON_MASK 0x3
#define MAX5970_MON(reg, ch) (((reg) >> ((ch) * 2)) & MAX5970_MON_MASK)
#define MAX5970_MON_MAX_RANGE_UV 16000000
#define MAX5970_REG_CH_UV_WARN_H(ch) (0x1A + (ch) * 10)
#define MAX5970_REG_CH_UV_WARN_L(ch) (0x1B + (ch) * 10)
#define MAX5970_REG_CH_UV_CRIT_H(ch) (0x1C + (ch) * 10)
#define MAX5970_REG_CH_UV_CRIT_L(ch) (0x1D + (ch) * 10)
#define MAX5970_REG_CH_OV_WARN_H(ch) (0x1E + (ch) * 10)
#define MAX5970_REG_CH_OV_WARN_L(ch) (0x1F + (ch) * 10)
#define MAX5970_REG_CH_OV_CRIT_H(ch) (0x20 + (ch) * 10)
#define MAX5970_REG_CH_OV_CRIT_L(ch) (0x21 + (ch) * 10)
#define MAX5970_VAL2REG_H(x) (((x) >> 2) & 0xFF)
#define MAX5970_VAL2REG_L(x) ((x) & 0x3)
#define MAX5970_REG_DAC_FAST(ch) (0x2E + (ch))
#define MAX5970_FAST2SLOW_RATIO 200
#define MAX5970_REG_STATUS0 0x31
#define MAX5970_CB_IFAULTF(ch) (1 << (ch))
#define MAX5970_CB_IFAULTS(ch) (1 << ((ch) + 4))
#define MAX5970_REG_STATUS1 0x32
#define STATUS1_PROT_MASK 0x3
#define STATUS1_PROT(reg) \
(((reg) >> 6) & STATUS1_PROT_MASK)
#define STATUS1_PROT_SHUTDOWN 0
#define STATUS1_PROT_CLEAR_PG 1
#define STATUS1_PROT_ALERT_ONLY 2
#define MAX5970_REG_STATUS2 0x33
#define MAX5970_IRNG_MASK 0x3
#define MAX5970_IRNG(reg, ch) \
(((reg) >> ((ch) * 2)) & MAX5970_IRNG_MASK)
#define MAX5970_REG_STATUS3 0x34
#define MAX5970_STATUS3_ALERT BIT(4)
#define MAX5970_STATUS3_PG(ch) BIT(ch)
#define MAX5970_REG_FAULT0 0x35
#define UV_STATUS_WARN(ch) (1 << (ch))
#define UV_STATUS_CRIT(ch) (1 << ((ch) + 4))
#define MAX5970_REG_FAULT1 0x36
#define OV_STATUS_WARN(ch) (1 << (ch))
#define OV_STATUS_CRIT(ch) (1 << ((ch) + 4))
#define MAX5970_REG_FAULT2 0x37
#define OC_STATUS_WARN(ch) (1 << (ch))
#define MAX5970_REG_CHXEN 0x3b
#define CHXEN(ch) (3 << ((ch) * 2))
#define MAX5970_REG_LED_FLASH 0x43
#define MAX_REGISTERS 0x49
#define ADC_MASK 0x3FF
#endif /* _MFD_MAX597X_H */