drivers/mfd/khadas-mcu.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for Khadas System control Microcontroller
   4  *
   5  * Copyright (C) 2020 BayLibre SAS
   6  *
   7  * Author(s): Neil Armstrong <narmstrong@baylibre.com>
   8  */
   9 #include <linux/bitfield.h>
  10 #include <linux/i2c.h>
  11 #include <linux/mfd/core.h>
  12 #include <linux/mfd/khadas-mcu.h>
  13 #include <linux/module.h>
  14 #include <linux/regmap.h>
  15
  16 static bool khadas_mcu_reg_volatile(struct device *dev, unsigned int reg)
  17 {
  18         if (reg >= KHADAS_MCU_USER_DATA_0_REG &&
  19             reg < KHADAS_MCU_PWR_OFF_CMD_REG)
  20                 return true;
  21
  22         switch (reg) {
  23         case KHADAS_MCU_PWR_OFF_CMD_REG:
  24         case KHADAS_MCU_PASSWD_START_REG:
  25         case KHADAS_MCU_CHECK_VEN_PASSWD_REG:
  26         case KHADAS_MCU_CHECK_USER_PASSWD_REG:
  27         case KHADAS_MCU_WOL_INIT_START_REG:
  28         case KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG:
  29                 return true;
  30         default:
  31                 return false;
  32         }
  33 }
  34
  35 static bool khadas_mcu_reg_writeable(struct device *dev, unsigned int reg)
  36 {
  37         switch (reg) {
  38         case KHADAS_MCU_PASSWD_VEN_0_REG:
  39         case KHADAS_MCU_PASSWD_VEN_1_REG:
  40         case KHADAS_MCU_PASSWD_VEN_2_REG:
  41         case KHADAS_MCU_PASSWD_VEN_3_REG:
  42         case KHADAS_MCU_PASSWD_VEN_4_REG:
  43         case KHADAS_MCU_PASSWD_VEN_5_REG:
  44         case KHADAS_MCU_MAC_0_REG:
  45         case KHADAS_MCU_MAC_1_REG:
  46         case KHADAS_MCU_MAC_2_REG:
  47         case KHADAS_MCU_MAC_3_REG:
  48         case KHADAS_MCU_MAC_4_REG:
  49         case KHADAS_MCU_MAC_5_REG:
  50         case KHADAS_MCU_USID_0_REG:
  51         case KHADAS_MCU_USID_1_REG:
  52         case KHADAS_MCU_USID_2_REG:
  53         case KHADAS_MCU_USID_3_REG:
  54         case KHADAS_MCU_USID_4_REG:
  55         case KHADAS_MCU_USID_5_REG:
  56         case KHADAS_MCU_VERSION_0_REG:
  57         case KHADAS_MCU_VERSION_1_REG:
  58         case KHADAS_MCU_DEVICE_NO_0_REG:
  59         case KHADAS_MCU_DEVICE_NO_1_REG:
  60         case KHADAS_MCU_FACTORY_TEST_REG:
  61         case KHADAS_MCU_SHUTDOWN_NORMAL_STATUS_REG:
  62                 return false;
  63         default:
  64                 return true;
  65         }
  66 }
  67
  68 static const struct regmap_config khadas_mcu_regmap_config = {
  69         .reg_bits       = 8,
  70         .reg_stride     = 1,
  71         .val_bits       = 8,
  72         .max_register   = KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
  73         .volatile_reg   = khadas_mcu_reg_volatile,
  74         .writeable_reg  = khadas_mcu_reg_writeable,
  75         .cache_type     = REGCACHE_RBTREE,
  76 };
  77
  78 static struct mfd_cell khadas_mcu_fan_cells[] = {
  79         /* VIM1/2 Rev13+ and VIM3 only */
  80         { .name = "khadas-mcu-fan-ctrl", },
  81 };
  82
  83 static struct mfd_cell khadas_mcu_cells[] = {
  84         { .name = "khadas-mcu-user-mem", },
  85 };
  86
  87 static int khadas_mcu_probe(struct i2c_client *client,
  88                        const struct i2c_device_id *id)
  89 {
  90         struct device *dev = &client->dev;
  91         struct khadas_mcu *ddata;
  92         int ret;
  93
  94         ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
  95         if (!ddata)
  96                 return -ENOMEM;
  97
  98         i2c_set_clientdata(client, ddata);
  99
 100         ddata->dev = dev;
 101
 102         ddata->regmap = devm_regmap_init_i2c(client, &khadas_mcu_regmap_config);
 103         if (IS_ERR(ddata->regmap)) {
 104                 ret = PTR_ERR(ddata->regmap);
 105                 dev_err(dev, "Failed to allocate register map: %d\n", ret);
 106                 return ret;
 107         }
 108
 109         ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
 110                                    khadas_mcu_cells,
 111                                    ARRAY_SIZE(khadas_mcu_cells),
 112                                    NULL, 0, NULL);
 113         if (ret)
 114                 return ret;
 115
 116         if (of_find_property(dev->of_node, "#cooling-cells", NULL))
 117                 return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
 118                                             khadas_mcu_fan_cells,
 119                                             ARRAY_SIZE(khadas_mcu_fan_cells),
 120                                             NULL, 0, NULL);
 121
 122         return 0;
 123 }
 124
 125 #ifdef CONFIG_OF
 126 static const struct of_device_id khadas_mcu_of_match[] = {
 127         { .compatible = "khadas,mcu", },
 128         {},
 129 };
 130 MODULE_DEVICE_TABLE(of, khadas_mcu_of_match);
 131 #endif
 132
 133 static struct i2c_driver khadas_mcu_driver = {
 134         .driver = {
 135                 .name = "khadas-mcu-core",
 136                 .of_match_table = of_match_ptr(khadas_mcu_of_match),
 137         },
 138         .probe = khadas_mcu_probe,
 139 };
 140 module_i2c_driver(khadas_mcu_driver);
 141
 142 MODULE_DESCRIPTION("Khadas MCU core driver");
 143 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
 144 MODULE_LICENSE("GPL v2");