// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de> * Copyright (c) 2017 Pengutronix, Oleksij Rempel <kernel@pengutronix.de> */ #include <linux/mfd/syscon.h> #include <linux/module.h> #include <linux/nvmem-provider.h> #include <linux/of_device.h> #include <linux/regmap.h> #define IMX6Q_SNVS_HPLR 0x00 #define IMX6Q_SNVS_LPLR 0x34 #define IMX6Q_SNVS_LPGPR 0x68 #define IMX7D_SNVS_HPLR 0x00 #define IMX7D_SNVS_LPLR 0x34 #define IMX7D_SNVS_LPGPR 0x90 #define IMX_GPR_SL BIT(5) #define IMX_GPR_HL BIT(5) struct snvs_lpgpr_cfg { int offset; int offset_hplr; int offset_lplr; int size; }; struct snvs_lpgpr_priv { struct device_d *dev; struct regmap *regmap; struct nvmem_config cfg; const struct snvs_lpgpr_cfg *dcfg; }; static const struct snvs_lpgpr_cfg snvs_lpgpr_cfg_imx6q = { .offset = IMX6Q_SNVS_LPGPR, .offset_hplr = IMX6Q_SNVS_HPLR, .offset_lplr = IMX6Q_SNVS_LPLR, .size = 4, }; static const struct snvs_lpgpr_cfg snvs_lpgpr_cfg_imx7d = { .offset = IMX7D_SNVS_LPGPR, .offset_hplr = IMX7D_SNVS_HPLR, .offset_lplr = IMX7D_SNVS_LPLR, .size = 16, }; static int snvs_lpgpr_write(void *context, unsigned int offset, void *val, size_t bytes) { struct snvs_lpgpr_priv *priv = context; const struct snvs_lpgpr_cfg *dcfg = priv->dcfg; unsigned int lock_reg; int ret; ret = regmap_read(priv->regmap, dcfg->offset_hplr, &lock_reg); if (ret < 0) return ret; if (lock_reg & IMX_GPR_SL) return -EPERM; ret = regmap_read(priv->regmap, dcfg->offset_lplr, &lock_reg); if (ret < 0) return ret; if (lock_reg & IMX_GPR_HL) return -EPERM; return regmap_bulk_write(priv->regmap, dcfg->offset + offset, val, bytes / 4); } static int snvs_lpgpr_read(void *context, unsigned int offset, void *val, size_t bytes) { struct snvs_lpgpr_priv *priv = context; const struct snvs_lpgpr_cfg *dcfg = priv->dcfg; return regmap_bulk_read(priv->regmap, dcfg->offset + offset, val, bytes / 4); } static int snvs_lpgpr_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *node = dev->of_node; struct device_node *syscon_node; struct snvs_lpgpr_priv *priv; struct nvmem_config *cfg; struct nvmem_device *nvmem; const struct snvs_lpgpr_cfg *dcfg; if (!node) return -ENOENT; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; dcfg = of_device_get_match_data(dev); if (!dcfg) return -EINVAL; syscon_node = of_get_parent(node); if (!syscon_node) return -ENODEV; priv->regmap = syscon_node_to_regmap(syscon_node); of_node_put(syscon_node); if (IS_ERR(priv->regmap)) return PTR_ERR(priv->regmap); priv->dcfg = dcfg; cfg = &priv->cfg; cfg->priv = priv; cfg->name = dev_name(dev); cfg->dev = dev; cfg->stride = 4; cfg->word_size = 4; cfg->size = dcfg->size; cfg->owner = THIS_MODULE; cfg->reg_read = snvs_lpgpr_read; cfg->reg_write = snvs_lpgpr_write; nvmem = devm_nvmem_register(dev, cfg); return PTR_ERR_OR_ZERO(nvmem); } static const struct of_device_id snvs_lpgpr_dt_ids[] = { { .compatible = "fsl,imx6q-snvs-lpgpr", .data = &snvs_lpgpr_cfg_imx6q }, { .compatible = "fsl,imx6ul-snvs-lpgpr", .data = &snvs_lpgpr_cfg_imx6q }, { .compatible = "fsl,imx7d-snvs-lpgpr", .data = &snvs_lpgpr_cfg_imx7d }, { }, }; MODULE_DEVICE_TABLE(of, snvs_lpgpr_dt_ids); static struct platform_driver snvs_lpgpr_driver = { .probe = snvs_lpgpr_probe, .driver = { .name = "snvs_lpgpr", .of_match_table = snvs_lpgpr_dt_ids, }, }; module_platform_driver(snvs_lpgpr_driver); MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>"); MODULE_DESCRIPTION("Low Power General Purpose Register in i.MX6 and i.MX7 Secure Non-Volatile Storage"); MODULE_LICENSE("GPL v2");