linux/drivers/mfd/max77714.c
Luca Ceresoli 60b050ff3a mfd: max77714: Add driver for Maxim MAX77714 PMIC
Add a simple driver for the Maxim MAX77714 PMIC, supporting RTC and
watchdog only.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2022-03-07 13:54:44 +00:00

153 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Maxim MAX77714 Core Driver
*
* Copyright (C) 2022 Luca Ceresoli
* Author: Luca Ceresoli <luca@lucaceresoli.net>
*/
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/mfd/core.h>
#include <linux/mfd/max77714.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>
static const struct mfd_cell max77714_cells[] = {
{ .name = "max77714-watchdog" },
{ .name = "max77714-rtc" },
};
static const struct regmap_range max77714_readable_ranges[] = {
regmap_reg_range(MAX77714_INT_TOP, MAX77714_INT_TOP),
regmap_reg_range(MAX77714_INT_TOPM, MAX77714_INT_TOPM),
regmap_reg_range(MAX77714_32K_STATUS, MAX77714_32K_CONFIG),
regmap_reg_range(MAX77714_CNFG_GLBL2, MAX77714_CNFG2_ONOFF),
};
static const struct regmap_range max77714_writable_ranges[] = {
regmap_reg_range(MAX77714_INT_TOPM, MAX77714_INT_TOPM),
regmap_reg_range(MAX77714_32K_CONFIG, MAX77714_32K_CONFIG),
regmap_reg_range(MAX77714_CNFG_GLBL2, MAX77714_CNFG2_ONOFF),
};
static const struct regmap_access_table max77714_readable_table = {
.yes_ranges = max77714_readable_ranges,
.n_yes_ranges = ARRAY_SIZE(max77714_readable_ranges),
};
static const struct regmap_access_table max77714_writable_table = {
.yes_ranges = max77714_writable_ranges,
.n_yes_ranges = ARRAY_SIZE(max77714_writable_ranges),
};
static const struct regmap_config max77714_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = MAX77714_CNFG2_ONOFF,
.rd_table = &max77714_readable_table,
.wr_table = &max77714_writable_table,
};
static const struct regmap_irq max77714_top_irqs[] = {
REGMAP_IRQ_REG(MAX77714_IRQ_TOP_ONOFF, 0, MAX77714_INT_TOP_ONOFF),
REGMAP_IRQ_REG(MAX77714_IRQ_TOP_RTC, 0, MAX77714_INT_TOP_RTC),
REGMAP_IRQ_REG(MAX77714_IRQ_TOP_GPIO, 0, MAX77714_INT_TOP_GPIO),
REGMAP_IRQ_REG(MAX77714_IRQ_TOP_LDO, 0, MAX77714_INT_TOP_LDO),
REGMAP_IRQ_REG(MAX77714_IRQ_TOP_SD, 0, MAX77714_INT_TOP_SD),
REGMAP_IRQ_REG(MAX77714_IRQ_TOP_GLBL, 0, MAX77714_INT_TOP_GLBL),
};
static const struct regmap_irq_chip max77714_irq_chip = {
.name = "max77714-pmic",
.status_base = MAX77714_INT_TOP,
.mask_base = MAX77714_INT_TOPM,
.num_regs = 1,
.irqs = max77714_top_irqs,
.num_irqs = ARRAY_SIZE(max77714_top_irqs),
};
/*
* MAX77714 initially uses the internal, low precision oscillator. Enable
* the external oscillator by setting the XOSC_RETRY bit. If the external
* oscillator is not OK (probably not installed) this has no effect.
*/
static int max77714_setup_xosc(struct device *dev, struct regmap *regmap)
{
/* Internal Crystal Load Capacitance, indexed by value of 32KLOAD bits */
static const unsigned int load_cap[4] = {0, 10, 12, 22}; /* pF */
unsigned int load_cap_idx;
unsigned int status;
int err;
err = regmap_update_bits(regmap, MAX77714_32K_CONFIG,
MAX77714_32K_CONFIG_XOSC_RETRY,
MAX77714_32K_CONFIG_XOSC_RETRY);
if (err)
return dev_err_probe(dev, err, "Failed to configure the external oscillator\n");
err = regmap_read(regmap, MAX77714_32K_STATUS, &status);
if (err)
return dev_err_probe(dev, err, "Failed to read external oscillator status\n");
load_cap_idx = (status >> MAX77714_32K_STATUS_32KLOAD_SHF)
& MAX77714_32K_STATUS_32KLOAD_MSK;
dev_info(dev, "Using %s oscillator, %d pF load cap\n",
status & MAX77714_32K_STATUS_32KSOURCE ? "internal" : "external",
load_cap[load_cap_idx]);
return 0;
}
static int max77714_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct regmap *regmap;
struct regmap_irq_chip_data *irq_data;
int err;
regmap = devm_regmap_init_i2c(client, &max77714_regmap_config);
if (IS_ERR(regmap))
return dev_err_probe(dev, PTR_ERR(regmap),
"Failed to initialise regmap\n");
err = max77714_setup_xosc(dev, regmap);
if (err)
return err;
err = devm_regmap_add_irq_chip(dev, regmap, client->irq,
IRQF_ONESHOT | IRQF_SHARED, 0,
&max77714_irq_chip, &irq_data);
if (err)
return dev_err_probe(dev, err, "Failed to add PMIC IRQ chip\n");
err = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
max77714_cells, ARRAY_SIZE(max77714_cells),
NULL, 0, NULL);
if (err)
return dev_err_probe(dev, err, "Failed to register child devices\n");
return 0;
}
static const struct of_device_id max77714_dt_match[] = {
{ .compatible = "maxim,max77714" },
{},
};
MODULE_DEVICE_TABLE(of, max77714_dt_match);
static struct i2c_driver max77714_driver = {
.driver = {
.name = "max77714",
.of_match_table = max77714_dt_match,
},
.probe_new = max77714_probe,
};
module_i2c_driver(max77714_driver);
MODULE_DESCRIPTION("Maxim MAX77714 MFD core driver");
MODULE_AUTHOR("Luca Ceresoli <luca@lucaceresoli.net>");
MODULE_LICENSE("GPL");