1988437aeSOleksij Rempel /* 2988437aeSOleksij Rempel * Copyright (c) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de> 3988437aeSOleksij Rempel * Copyright (c) 2017 Pengutronix, Oleksij Rempel <kernel@pengutronix.de> 4988437aeSOleksij Rempel * 5988437aeSOleksij Rempel * This program is free software; you can redistribute it and/or modify 6988437aeSOleksij Rempel * it under the terms of the GNU General Public License version 2 7988437aeSOleksij Rempel * as published by the Free Software Foundation. 8988437aeSOleksij Rempel */ 9988437aeSOleksij Rempel 10988437aeSOleksij Rempel #include <linux/mfd/syscon.h> 11988437aeSOleksij Rempel #include <linux/module.h> 12988437aeSOleksij Rempel #include <linux/nvmem-provider.h> 13988437aeSOleksij Rempel #include <linux/of_device.h> 14988437aeSOleksij Rempel #include <linux/regmap.h> 15988437aeSOleksij Rempel 16988437aeSOleksij Rempel #define IMX6Q_SNVS_HPLR 0x00 17988437aeSOleksij Rempel #define IMX6Q_GPR_SL BIT(5) 18988437aeSOleksij Rempel #define IMX6Q_SNVS_LPLR 0x34 19988437aeSOleksij Rempel #define IMX6Q_GPR_HL BIT(5) 20988437aeSOleksij Rempel #define IMX6Q_SNVS_LPGPR 0x68 21988437aeSOleksij Rempel 22988437aeSOleksij Rempel struct snvs_lpgpr_cfg { 23988437aeSOleksij Rempel int offset; 24988437aeSOleksij Rempel int offset_hplr; 25988437aeSOleksij Rempel int offset_lplr; 26988437aeSOleksij Rempel }; 27988437aeSOleksij Rempel 28988437aeSOleksij Rempel struct snvs_lpgpr_priv { 29988437aeSOleksij Rempel struct device_d *dev; 30988437aeSOleksij Rempel struct regmap *regmap; 31988437aeSOleksij Rempel struct nvmem_config cfg; 32988437aeSOleksij Rempel const struct snvs_lpgpr_cfg *dcfg; 33988437aeSOleksij Rempel }; 34988437aeSOleksij Rempel 35988437aeSOleksij Rempel static const struct snvs_lpgpr_cfg snvs_lpgpr_cfg_imx6q = { 36988437aeSOleksij Rempel .offset = IMX6Q_SNVS_LPGPR, 37988437aeSOleksij Rempel .offset_hplr = IMX6Q_SNVS_HPLR, 38988437aeSOleksij Rempel .offset_lplr = IMX6Q_SNVS_LPLR, 39988437aeSOleksij Rempel }; 40988437aeSOleksij Rempel 41988437aeSOleksij Rempel static int snvs_lpgpr_write(void *context, unsigned int offset, void *val, 42988437aeSOleksij Rempel size_t bytes) 43988437aeSOleksij Rempel { 44988437aeSOleksij Rempel struct snvs_lpgpr_priv *priv = context; 45988437aeSOleksij Rempel const struct snvs_lpgpr_cfg *dcfg = priv->dcfg; 46988437aeSOleksij Rempel unsigned int lock_reg; 47988437aeSOleksij Rempel int ret; 48988437aeSOleksij Rempel 49988437aeSOleksij Rempel ret = regmap_read(priv->regmap, dcfg->offset_hplr, &lock_reg); 50988437aeSOleksij Rempel if (ret < 0) 51988437aeSOleksij Rempel return ret; 52988437aeSOleksij Rempel 53988437aeSOleksij Rempel if (lock_reg & IMX6Q_GPR_SL) 54988437aeSOleksij Rempel return -EPERM; 55988437aeSOleksij Rempel 56988437aeSOleksij Rempel ret = regmap_read(priv->regmap, dcfg->offset_lplr, &lock_reg); 57988437aeSOleksij Rempel if (ret < 0) 58988437aeSOleksij Rempel return ret; 59988437aeSOleksij Rempel 60988437aeSOleksij Rempel if (lock_reg & IMX6Q_GPR_HL) 61988437aeSOleksij Rempel return -EPERM; 62988437aeSOleksij Rempel 63988437aeSOleksij Rempel return regmap_bulk_write(priv->regmap, dcfg->offset + offset, val, 64988437aeSOleksij Rempel bytes / 4); 65988437aeSOleksij Rempel } 66988437aeSOleksij Rempel 67988437aeSOleksij Rempel static int snvs_lpgpr_read(void *context, unsigned int offset, void *val, 68988437aeSOleksij Rempel size_t bytes) 69988437aeSOleksij Rempel { 70988437aeSOleksij Rempel struct snvs_lpgpr_priv *priv = context; 71988437aeSOleksij Rempel const struct snvs_lpgpr_cfg *dcfg = priv->dcfg; 72988437aeSOleksij Rempel 73988437aeSOleksij Rempel return regmap_bulk_read(priv->regmap, dcfg->offset + offset, 74988437aeSOleksij Rempel val, bytes / 4); 75988437aeSOleksij Rempel } 76988437aeSOleksij Rempel 77988437aeSOleksij Rempel static int snvs_lpgpr_probe(struct platform_device *pdev) 78988437aeSOleksij Rempel { 79988437aeSOleksij Rempel struct device *dev = &pdev->dev; 80988437aeSOleksij Rempel struct device_node *node = dev->of_node; 81988437aeSOleksij Rempel struct device_node *syscon_node; 82988437aeSOleksij Rempel struct snvs_lpgpr_priv *priv; 83988437aeSOleksij Rempel struct nvmem_config *cfg; 84988437aeSOleksij Rempel struct nvmem_device *nvmem; 85988437aeSOleksij Rempel const struct snvs_lpgpr_cfg *dcfg; 86988437aeSOleksij Rempel 87988437aeSOleksij Rempel if (!node) 88988437aeSOleksij Rempel return -ENOENT; 89988437aeSOleksij Rempel 90988437aeSOleksij Rempel priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 91988437aeSOleksij Rempel if (!priv) 92988437aeSOleksij Rempel return -ENOMEM; 93988437aeSOleksij Rempel 94988437aeSOleksij Rempel dcfg = of_device_get_match_data(dev); 95988437aeSOleksij Rempel if (!dcfg) 96988437aeSOleksij Rempel return -EINVAL; 97988437aeSOleksij Rempel 98988437aeSOleksij Rempel syscon_node = of_get_parent(node); 99988437aeSOleksij Rempel if (!syscon_node) 100988437aeSOleksij Rempel return -ENODEV; 101988437aeSOleksij Rempel 102988437aeSOleksij Rempel priv->regmap = syscon_node_to_regmap(syscon_node); 103988437aeSOleksij Rempel of_node_put(syscon_node); 104988437aeSOleksij Rempel if (IS_ERR(priv->regmap)) 105988437aeSOleksij Rempel return PTR_ERR(priv->regmap); 106988437aeSOleksij Rempel 107988437aeSOleksij Rempel priv->dcfg = dcfg; 108988437aeSOleksij Rempel 109988437aeSOleksij Rempel cfg = &priv->cfg; 110988437aeSOleksij Rempel cfg->priv = priv; 111988437aeSOleksij Rempel cfg->name = dev_name(dev); 112988437aeSOleksij Rempel cfg->dev = dev; 113988437aeSOleksij Rempel cfg->stride = 4, 114988437aeSOleksij Rempel cfg->word_size = 4, 115988437aeSOleksij Rempel cfg->size = 4, 116988437aeSOleksij Rempel cfg->owner = THIS_MODULE, 117988437aeSOleksij Rempel cfg->reg_read = snvs_lpgpr_read, 118988437aeSOleksij Rempel cfg->reg_write = snvs_lpgpr_write, 119988437aeSOleksij Rempel 120988437aeSOleksij Rempel nvmem = nvmem_register(cfg); 121988437aeSOleksij Rempel if (IS_ERR(nvmem)) 122988437aeSOleksij Rempel return PTR_ERR(nvmem); 123988437aeSOleksij Rempel 124988437aeSOleksij Rempel platform_set_drvdata(pdev, nvmem); 125988437aeSOleksij Rempel 126988437aeSOleksij Rempel return 0; 127988437aeSOleksij Rempel } 128988437aeSOleksij Rempel 129988437aeSOleksij Rempel static int snvs_lpgpr_remove(struct platform_device *pdev) 130988437aeSOleksij Rempel { 131988437aeSOleksij Rempel struct nvmem_device *nvmem = platform_get_drvdata(pdev); 132988437aeSOleksij Rempel 133988437aeSOleksij Rempel return nvmem_unregister(nvmem); 134988437aeSOleksij Rempel } 135988437aeSOleksij Rempel 136988437aeSOleksij Rempel static const struct of_device_id snvs_lpgpr_dt_ids[] = { 137988437aeSOleksij Rempel { .compatible = "fsl,imx6q-snvs-lpgpr", .data = &snvs_lpgpr_cfg_imx6q }, 138988437aeSOleksij Rempel { .compatible = "fsl,imx6ul-snvs-lpgpr", 139988437aeSOleksij Rempel .data = &snvs_lpgpr_cfg_imx6q }, 140988437aeSOleksij Rempel { }, 141988437aeSOleksij Rempel }; 142988437aeSOleksij Rempel MODULE_DEVICE_TABLE(of, snvs_lpgpr_dt_ids); 143988437aeSOleksij Rempel 144988437aeSOleksij Rempel static struct platform_driver snvs_lpgpr_driver = { 145988437aeSOleksij Rempel .probe = snvs_lpgpr_probe, 146988437aeSOleksij Rempel .remove = snvs_lpgpr_remove, 147988437aeSOleksij Rempel .driver = { 148988437aeSOleksij Rempel .name = "snvs_lpgpr", 149988437aeSOleksij Rempel .of_match_table = snvs_lpgpr_dt_ids, 150988437aeSOleksij Rempel }, 151988437aeSOleksij Rempel }; 152988437aeSOleksij Rempel module_platform_driver(snvs_lpgpr_driver); 153988437aeSOleksij Rempel 154988437aeSOleksij Rempel MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>"); 155988437aeSOleksij Rempel MODULE_DESCRIPTION("Low Power General Purpose Register in i.MX6 Secure Non-Volatile Storage"); 156988437aeSOleksij Rempel MODULE_LICENSE("GPL v2"); 157