drivers/mfd/max77714.c

   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.ceresoli@bootlin.com>
   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
  17 static const struct mfd_cell max77714_cells[] = {
  18         { .name = "max77714-watchdog" },
  19         { .name = "max77714-rtc" },
  20 };
  21
  22 static 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
  29 static 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
  35 static 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
  40 static 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
  45 static 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
  53 static 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
  62 static 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  */
  76 static 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
 104 static 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
 135 static const struct of_device_id max77714_dt_match[] = {
 136         { .compatible = "maxim,max77714" },
 137         {},
 138 };
 139 MODULE_DEVICE_TABLE(of, max77714_dt_match);
 140
 141 static struct i2c_driver max77714_driver = {
 142         .driver = {
 143                 .name = "max77714",
 144                 .of_match_table = max77714_dt_match,
 145         },
 146         .probe = max77714_probe,
 147 };
 148 module_i2c_driver(max77714_driver);
 149
 150 MODULE_DESCRIPTION("Maxim MAX77714 MFD core driver");
 151 MODULE_AUTHOR("Luca Ceresoli <luca.ceresoli@bootlin.com>");
 152 MODULE_LICENSE("GPL");