projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 988437ae OR |
1 | /* |
| 2 | * Copyright (c) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de> | |
| 3 | * Copyright (c) 2017 Pengutronix, Oleksij Rempel <kernel@pengutronix.de> | |
| 4 | * | |
| 5 | * This program is free software; you can redistribute it and/or modify | |
| 6 | * it under the terms of the GNU General Public License version 2 | |
| 7 | * as published by the Free Software Foundation. | |
| 8 | */ | |
| 9 | ||
| 10 | #include <linux/mfd/syscon.h> | |
| 11 | #include <linux/module.h> | |
| 12 | #include <linux/nvmem-provider.h> | |
| 13 | #include <linux/of_device.h> | |
| 14 | #include <linux/regmap.h> | |
| 15 | ||
| 16 | #define IMX6Q_SNVS_HPLR 0x00 | |
| 17 | #define IMX6Q_GPR_SL BIT(5) | |
| 18 | #define IMX6Q_SNVS_LPLR 0x34 | |
| 19 | #define IMX6Q_GPR_HL BIT(5) | |
| 20 | #define IMX6Q_SNVS_LPGPR 0x68 | |
| 21 | ||
| 22 | struct snvs_lpgpr_cfg { | |
| 23 | int offset; | |
| 24 | int offset_hplr; | |
| 25 | int offset_lplr; | |
| 26 | }; | |
| 27 | ||
| 28 | struct snvs_lpgpr_priv { | |
| 29 | struct device_d *dev; | |
| 30 | struct regmap *regmap; | |
| 31 | struct nvmem_config cfg; | |
| 32 | const struct snvs_lpgpr_cfg *dcfg; | |
| 33 | }; | |
| 34 | ||
| 35 | static const struct snvs_lpgpr_cfg snvs_lpgpr_cfg_imx6q = { | |
| 36 | .offset = IMX6Q_SNVS_LPGPR, | |
| 37 | .offset_hplr = IMX6Q_SNVS_HPLR, | |
| 38 | .offset_lplr = IMX6Q_SNVS_LPLR, | |
| 39 | }; | |
| 40 | ||
| 41 | static int snvs_lpgpr_write(void *context, unsigned int offset, void *val, | |
| 42 | size_t bytes) | |
| 43 | { | |
| 44 | struct snvs_lpgpr_priv *priv = context; | |
| 45 | const struct snvs_lpgpr_cfg *dcfg = priv->dcfg; | |
| 46 | unsigned int lock_reg; | |
| 47 | int ret; | |
| 48 | ||
| 49 | ret = regmap_read(priv->regmap, dcfg->offset_hplr, &lock_reg); | |
| 50 | if (ret < 0) | |
| 51 | return ret; | |
| 52 | ||
| 53 | if (lock_reg & IMX6Q_GPR_SL) | |
| 54 | return -EPERM; | |
| 55 | ||
| 56 | ret = regmap_read(priv->regmap, dcfg->offset_lplr, &lock_reg); | |
| 57 | if (ret < 0) | |
| 58 | return ret; | |
| 59 | ||
| 60 | if (lock_reg & IMX6Q_GPR_HL) | |
| 61 | return -EPERM; | |
| 62 | ||
| 63 | return regmap_bulk_write(priv->regmap, dcfg->offset + offset, val, | |
| 64 | bytes / 4); | |
| 65 | } | |
| 66 | ||
| 67 | static int snvs_lpgpr_read(void *context, unsigned int offset, void *val, | |
| 68 | size_t bytes) | |
| 69 | { | |
| 70 | struct snvs_lpgpr_priv *priv = context; | |
| 71 | const struct snvs_lpgpr_cfg *dcfg = priv->dcfg; | |
| 72 | ||
| 73 | return regmap_bulk_read(priv->regmap, dcfg->offset + offset, | |
| 74 | val, bytes / 4); | |
| 75 | } | |
| 76 | ||
| 77 | static int snvs_lpgpr_probe(struct platform_device *pdev) | |
| 78 | { | |
| 79 | struct device *dev = &pdev->dev; | |
| 80 | struct device_node *node = dev->of_node; | |
| 81 | struct device_node *syscon_node; | |
| 82 | struct snvs_lpgpr_priv *priv; | |
| 83 | struct nvmem_config *cfg; | |
| 84 | struct nvmem_device *nvmem; | |
| 85 | const struct snvs_lpgpr_cfg *dcfg; | |
| 86 | ||
| 87 | if (!node) | |
| 88 | return -ENOENT; | |
| 89 | ||
| 90 | priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); | |
| 91 | if (!priv) | |
| 92 | return -ENOMEM; | |
| 93 | ||
| 94 | dcfg = of_device_get_match_data(dev); | |
| 95 | if (!dcfg) | |
| 96 | return -EINVAL; | |
| 97 | ||
| 98 | syscon_node = of_get_parent(node); | |
| 99 | if (!syscon_node) | |
| 100 | return -ENODEV; | |
| 101 | ||
| 102 | priv->regmap = syscon_node_to_regmap(syscon_node); | |
| 103 | of_node_put(syscon_node); | |
| 104 | if (IS_ERR(priv->regmap)) | |
| 105 | return PTR_ERR(priv->regmap); | |
| 106 | ||
| 107 | priv->dcfg = dcfg; | |
| 108 | ||
| 109 | cfg = &priv->cfg; | |
| 110 | cfg->priv = priv; | |
| 111 | cfg->name = dev_name(dev); | |
| 112 | cfg->dev = dev; | |
| 113 | cfg->stride = 4, | |
| 114 | cfg->word_size = 4, | |
| 115 | cfg->size = 4, | |
| 116 | cfg->owner = THIS_MODULE, | |
| 117 | cfg->reg_read = snvs_lpgpr_read, | |
| 118 | cfg->reg_write = snvs_lpgpr_write, | |
| 119 | ||
| 120 | nvmem = nvmem_register(cfg); | |
| 121 | if (IS_ERR(nvmem)) | |
| 122 | return PTR_ERR(nvmem); | |
| 123 | ||
| 124 | platform_set_drvdata(pdev, nvmem); | |
| 125 | ||
| 126 | return 0; | |
| 127 | } | |
| 128 | ||
| 129 | static int snvs_lpgpr_remove(struct platform_device *pdev) | |
| 130 | { | |
| 131 | struct nvmem_device *nvmem = platform_get_drvdata(pdev); | |
| 132 | ||
| 133 | return nvmem_unregister(nvmem); | |
| 134 | } | |
| 135 | ||
| 136 | static const struct of_device_id snvs_lpgpr_dt_ids[] = { | |
| 137 | { .compatible = "fsl,imx6q-snvs-lpgpr", .data = &snvs_lpgpr_cfg_imx6q }, | |
| 138 | { .compatible = "fsl,imx6ul-snvs-lpgpr", | |
| 139 | .data = &snvs_lpgpr_cfg_imx6q }, | |
| 140 | { }, | |
| 141 | }; | |
| 142 | MODULE_DEVICE_TABLE(of, snvs_lpgpr_dt_ids); | |
| 143 | ||
| 144 | static struct platform_driver snvs_lpgpr_driver = { | |
| 145 | .probe = snvs_lpgpr_probe, | |
| 146 | .remove = snvs_lpgpr_remove, | |
| 147 | .driver = { | |
| 148 | .name = "snvs_lpgpr", | |
| 149 | .of_match_table = snvs_lpgpr_dt_ids, | |
| 150 | }, | |
| 151 | }; | |
| 152 | module_platform_driver(snvs_lpgpr_driver); | |
| 153 | ||
| 154 | MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>"); | |
| 155 | MODULE_DESCRIPTION("Low Power General Purpose Register in i.MX6 Secure Non-Volatile Storage"); | |
| 156 | MODULE_LICENSE("GPL v2"); |