diff options
Diffstat (limited to 'drivers/nvmem/snvs_lpgpr.c')
| -rw-r--r-- | drivers/nvmem/snvs_lpgpr.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/nvmem/snvs_lpgpr.c b/drivers/nvmem/snvs_lpgpr.c new file mode 100644 index 000000000..c050a23a9 --- /dev/null +++ b/drivers/nvmem/snvs_lpgpr.c @@ -0,0 +1,159 @@ +/* + * Copyright (c) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de> + * Copyright (c) 2017 Pengutronix, Oleksij Rempel <kernel@pengutronix.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + */ + +#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"); |