cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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max77714.c (4779B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Maxim MAX77714 Core Driver
      4 *
      5 * Copyright (C) 2022 Luca Ceresoli
      6 * Author: Luca Ceresoli <luca@lucaceresoli.net>
      7 */
      8
      9#include <linux/i2c.h>
     10#include <linux/interrupt.h>
     11#include <linux/mfd/core.h>
     12#include <linux/mfd/max77714.h>
     13#include <linux/module.h>
     14#include <linux/of.h>
     15#include <linux/regmap.h>
     16
     17static const struct mfd_cell max77714_cells[] = {
     18	{ .name = "max77714-watchdog" },
     19	{ .name = "max77714-rtc" },
     20};
     21
     22static const struct regmap_range max77714_readable_ranges[] = {
     23	regmap_reg_range(MAX77714_INT_TOP,     MAX77714_INT_TOP),
     24	regmap_reg_range(MAX77714_INT_TOPM,    MAX77714_INT_TOPM),
     25	regmap_reg_range(MAX77714_32K_STATUS,  MAX77714_32K_CONFIG),
     26	regmap_reg_range(MAX77714_CNFG_GLBL2,  MAX77714_CNFG2_ONOFF),
     27};
     28
     29static const struct regmap_range max77714_writable_ranges[] = {
     30	regmap_reg_range(MAX77714_INT_TOPM,    MAX77714_INT_TOPM),
     31	regmap_reg_range(MAX77714_32K_CONFIG,  MAX77714_32K_CONFIG),
     32	regmap_reg_range(MAX77714_CNFG_GLBL2,  MAX77714_CNFG2_ONOFF),
     33};
     34
     35static const struct regmap_access_table max77714_readable_table = {
     36	.yes_ranges = max77714_readable_ranges,
     37	.n_yes_ranges = ARRAY_SIZE(max77714_readable_ranges),
     38};
     39
     40static const struct regmap_access_table max77714_writable_table = {
     41	.yes_ranges = max77714_writable_ranges,
     42	.n_yes_ranges = ARRAY_SIZE(max77714_writable_ranges),
     43};
     44
     45static const struct regmap_config max77714_regmap_config = {
     46	.reg_bits = 8,
     47	.val_bits = 8,
     48	.max_register = MAX77714_CNFG2_ONOFF,
     49	.rd_table = &max77714_readable_table,
     50	.wr_table = &max77714_writable_table,
     51};
     52
     53static const struct regmap_irq max77714_top_irqs[] = {
     54	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_ONOFF,   0, MAX77714_INT_TOP_ONOFF),
     55	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_RTC,     0, MAX77714_INT_TOP_RTC),
     56	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_GPIO,    0, MAX77714_INT_TOP_GPIO),
     57	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_LDO,     0, MAX77714_INT_TOP_LDO),
     58	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_SD,      0, MAX77714_INT_TOP_SD),
     59	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_GLBL,    0, MAX77714_INT_TOP_GLBL),
     60};
     61
     62static const struct regmap_irq_chip max77714_irq_chip = {
     63	.name			= "max77714-pmic",
     64	.status_base		= MAX77714_INT_TOP,
     65	.mask_base		= MAX77714_INT_TOPM,
     66	.num_regs		= 1,
     67	.irqs			= max77714_top_irqs,
     68	.num_irqs		= ARRAY_SIZE(max77714_top_irqs),
     69};
     70
     71/*
     72 * MAX77714 initially uses the internal, low precision oscillator. Enable
     73 * the external oscillator by setting the XOSC_RETRY bit. If the external
     74 * oscillator is not OK (probably not installed) this has no effect.
     75 */
     76static int max77714_setup_xosc(struct device *dev, struct regmap *regmap)
     77{
     78	/* Internal Crystal Load Capacitance, indexed by value of 32KLOAD bits */
     79	static const unsigned int load_cap[4] = {0, 10, 12, 22}; /* pF */
     80	unsigned int load_cap_idx;
     81	unsigned int status;
     82	int err;
     83
     84	err = regmap_update_bits(regmap, MAX77714_32K_CONFIG,
     85				 MAX77714_32K_CONFIG_XOSC_RETRY,
     86				 MAX77714_32K_CONFIG_XOSC_RETRY);
     87	if (err)
     88		return dev_err_probe(dev, err, "Failed to configure the external oscillator\n");
     89
     90	err = regmap_read(regmap, MAX77714_32K_STATUS, &status);
     91	if (err)
     92		return dev_err_probe(dev, err, "Failed to read external oscillator status\n");
     93
     94	load_cap_idx = (status >> MAX77714_32K_STATUS_32KLOAD_SHF)
     95		& MAX77714_32K_STATUS_32KLOAD_MSK;
     96
     97	dev_info(dev, "Using %s oscillator, %d pF load cap\n",
     98		 status & MAX77714_32K_STATUS_32KSOURCE ? "internal" : "external",
     99		 load_cap[load_cap_idx]);
    100
    101	return 0;
    102}
    103
    104static int max77714_probe(struct i2c_client *client)
    105{
    106	struct device *dev = &client->dev;
    107	struct regmap *regmap;
    108	struct regmap_irq_chip_data *irq_data;
    109	int err;
    110
    111	regmap = devm_regmap_init_i2c(client, &max77714_regmap_config);
    112	if (IS_ERR(regmap))
    113		return dev_err_probe(dev, PTR_ERR(regmap),
    114				     "Failed to initialise regmap\n");
    115
    116	err = max77714_setup_xosc(dev, regmap);
    117	if (err)
    118		return err;
    119
    120	err = devm_regmap_add_irq_chip(dev, regmap, client->irq,
    121				       IRQF_ONESHOT | IRQF_SHARED, 0,
    122				       &max77714_irq_chip, &irq_data);
    123	if (err)
    124		return dev_err_probe(dev, err, "Failed to add PMIC IRQ chip\n");
    125
    126	err =  devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
    127				    max77714_cells, ARRAY_SIZE(max77714_cells),
    128				    NULL, 0, NULL);
    129	if (err)
    130		return dev_err_probe(dev, err, "Failed to register child devices\n");
    131
    132	return 0;
    133}
    134
    135static const struct of_device_id max77714_dt_match[] = {
    136	{ .compatible = "maxim,max77714" },
    137	{},
    138};
    139MODULE_DEVICE_TABLE(of, max77714_dt_match);
    140
    141static struct i2c_driver max77714_driver = {
    142	.driver = {
    143		.name = "max77714",
    144		.of_match_table = max77714_dt_match,
    145	},
    146	.probe_new = max77714_probe,
    147};
    148module_i2c_driver(max77714_driver);
    149
    150MODULE_DESCRIPTION("Maxim MAX77714 MFD core driver");
    151MODULE_AUTHOR("Luca Ceresoli <luca@lucaceresoli.net>");
    152MODULE_LICENSE("GPL");