diff options
Diffstat (limited to 'drivers/nvmem/qcom-spmi-sdam.c')
| -rw-r--r-- | drivers/nvmem/qcom-spmi-sdam.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/nvmem/qcom-spmi-sdam.c b/drivers/nvmem/qcom-spmi-sdam.c new file mode 100644 index 0000000000..70f2d4f2ef --- /dev/null +++ b/drivers/nvmem/qcom-spmi-sdam.c @@ -0,0 +1,181 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2017, 2020-2021, The Linux Foundation. All rights reserved. + */ + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/nvmem-provider.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#define SDAM_MEM_START 0x40 +#define REGISTER_MAP_ID 0x40 +#define REGISTER_MAP_VERSION 0x41 +#define SDAM_SIZE 0x44 +#define SDAM_PBS_TRIG_SET 0xE5 +#define SDAM_PBS_TRIG_CLR 0xE6 + +struct sdam_chip { + struct regmap *regmap; + struct nvmem_config sdam_config; + unsigned int base; + unsigned int size; +}; + +/* read only register offsets */ +static const u8 sdam_ro_map[] = { + REGISTER_MAP_ID, + REGISTER_MAP_VERSION, + SDAM_SIZE +}; + +static bool sdam_is_valid(struct sdam_chip *sdam, unsigned int offset, + size_t len) +{ + unsigned int sdam_mem_end = SDAM_MEM_START + sdam->size - 1; + + if (!len) + return false; + + if (offset >= SDAM_MEM_START && offset <= sdam_mem_end + && (offset + len - 1) <= sdam_mem_end) + return true; + else if ((offset == SDAM_PBS_TRIG_SET || offset == SDAM_PBS_TRIG_CLR) + && (len == 1)) + return true; + + return false; +} + +static bool sdam_is_ro(unsigned int offset, size_t len) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(sdam_ro_map); i++) + if (offset <= sdam_ro_map[i] && (offset + len) > sdam_ro_map[i]) + return true; + + return false; +} + +static int sdam_read(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct sdam_chip *sdam = priv; + struct device *dev = sdam->sdam_config.dev; + int rc; + + if (!sdam_is_valid(sdam, offset, bytes)) { + dev_err(dev, "Invalid SDAM offset %#x len=%zd\n", + offset, bytes); + return -EINVAL; + } + + rc = regmap_bulk_read(sdam->regmap, sdam->base + offset, val, bytes); + if (rc < 0) + dev_err(dev, "Failed to read SDAM offset %#x len=%zd, rc=%d\n", + offset, bytes, rc); + + return rc; +} + +static int sdam_write(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct sdam_chip *sdam = priv; + struct device *dev = sdam->sdam_config.dev; + int rc; + + if (!sdam_is_valid(sdam, offset, bytes)) { + dev_err(dev, "Invalid SDAM offset %#x len=%zd\n", + offset, bytes); + return -EINVAL; + } + + if (sdam_is_ro(offset, bytes)) { + dev_err(dev, "Invalid write offset %#x len=%zd\n", + offset, bytes); + return -EINVAL; + } + + rc = regmap_bulk_write(sdam->regmap, sdam->base + offset, val, bytes); + if (rc < 0) + dev_err(dev, "Failed to write SDAM offset %#x len=%zd, rc=%d\n", + offset, bytes, rc); + + return rc; +} + +static int sdam_probe(struct platform_device *pdev) +{ + struct sdam_chip *sdam; + struct nvmem_device *nvmem; + unsigned int val; + int rc; + + sdam = devm_kzalloc(&pdev->dev, sizeof(*sdam), GFP_KERNEL); + if (!sdam) + return -ENOMEM; + + sdam->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!sdam->regmap) { + dev_err(&pdev->dev, "Failed to get regmap handle\n"); + return -ENXIO; + } + + rc = of_property_read_u32(pdev->dev.of_node, "reg", &sdam->base); + if (rc < 0) { + dev_err(&pdev->dev, "Failed to get SDAM base, rc=%d\n", rc); + return -EINVAL; + } + + rc = regmap_read(sdam->regmap, sdam->base + SDAM_SIZE, &val); + if (rc < 0) { + dev_err(&pdev->dev, "Failed to read SDAM_SIZE rc=%d\n", rc); + return -EINVAL; + } + sdam->size = val * 32; + + sdam->sdam_config.dev = &pdev->dev; + sdam->sdam_config.name = "spmi_sdam"; + sdam->sdam_config.id = NVMEM_DEVID_AUTO; + sdam->sdam_config.owner = THIS_MODULE; + sdam->sdam_config.stride = 1; + sdam->sdam_config.word_size = 1; + sdam->sdam_config.reg_read = sdam_read; + sdam->sdam_config.reg_write = sdam_write; + sdam->sdam_config.priv = sdam; + + nvmem = devm_nvmem_register(&pdev->dev, &sdam->sdam_config); + if (IS_ERR(nvmem)) { + dev_err(&pdev->dev, + "Failed to register SDAM nvmem device rc=%ld\n", + PTR_ERR(nvmem)); + return -ENXIO; + } + dev_dbg(&pdev->dev, + "SDAM base=%#x size=%u registered successfully\n", + sdam->base, sdam->size); + + return 0; +} + +static const struct of_device_id sdam_match_table[] = { + { .compatible = "qcom,spmi-sdam" }, + {}, +}; +MODULE_DEVICE_TABLE(of, sdam_match_table); + +static struct platform_driver sdam_driver = { + .driver = { + .name = "qcom,spmi-sdam", + .of_match_table = sdam_match_table, + }, + .probe = sdam_probe, +}; +module_platform_driver(sdam_driver); + +MODULE_DESCRIPTION("QCOM SPMI SDAM driver"); +MODULE_LICENSE("GPL v2"); |