mt6691.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <console/console.h>
#include <device/i2c_simple.h>
#include <soc/mt6691.h>
 
#define MT6691_MIN_VOLTAGE              300000
#define MT6691_MAX_VOLTAGE              1300000
#define MT6691_STEP_UV                  5000
 
enum {
        MT6691_SLAVE_ADDR = 0x51,
};
 
int mt6691_set_voltage(uint8_t i2c_num, unsigned int volt_uv)
{
        uint8_t selector;
 
        if (volt_uv > MT6691_MAX_VOLTAGE || volt_uv < MT6691_MIN_VOLTAGE) {
                printk(BIOS_ERR, "%s: voltage out of range\n", __func__);
                return -1;
        }
 
        selector = DIV_ROUND_UP(volt_uv - MT6691_MIN_VOLTAGE, MT6691_STEP_UV);
 
        return i2c_write_field(i2c_num, MT6691_SLAVE_ADDR,
                               MT6691_VSEL0, selector, 0xFF, 0);
}
 
int mt6691_get_voltage(uint8_t i2c_num)
{
        uint8_t selector = 0;
        unsigned int volt;
 
        if (i2c_read_field(i2c_num, MT6691_SLAVE_ADDR, MT6691_VSEL0,
                           &selector, 0xFF, 0) < 0) {
                printk(BIOS_ERR, "%s: failed to get voltage from i2c\n", __func__);
                return -1;
        }
 
        volt = (selector * MT6691_STEP_UV) + MT6691_MIN_VOLTAGE;
 
        if (volt > MT6691_MAX_VOLTAGE) {
                printk(BIOS_ERR, "%s: voltage out of range\n", __func__);
                return -1;
        }
 
        return volt;
}
 
static uint8_t get_mt6691_chip_id(uint8_t i2c_num)
{
        uint8_t id;
 
        if (i2c_read_field(i2c_num, MT6691_SLAVE_ADDR, MT6691_MONITOR,
                           &id, 0x1, MT6691_PGOOD_SHIFT) < 0) {
                printk(BIOS_ERR, "%s: failed to read from i2c", __func__);
                return 0;
        }
 
        return id;
}
 
void mt6691_probe(uint8_t i2c_num)
{
        /* Check device ID is MT6691 */
        if (!get_mt6691_chip_id(i2c_num)) {
                printk(BIOS_ERR, "unknown MT6691 chip_id\n");
                return;
        }
        /* Slew rate 12mV */
        i2c_write_field(i2c_num, MT6691_SLAVE_ADDR, MT6691_CTRL2, 0x1,
                        MT6691_DN_SR_MASK, MT6691_DN_SR_SHIFT);
}