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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (c) 2017, 2020-2021, The Linux Foundation. All rights reserved.4 */5 6#include <linux/device.h>7#include <linux/module.h>8#include <linux/of.h>9#include <linux/nvmem-provider.h>10#include <linux/platform_device.h>11#include <linux/regmap.h>12 13#define SDAM_MEM_START 0x4014#define REGISTER_MAP_ID 0x4015#define REGISTER_MAP_VERSION 0x4116#define SDAM_SIZE 0x4417#define SDAM_PBS_TRIG_SET 0xE518#define SDAM_PBS_TRIG_CLR 0xE619 20struct sdam_chip {21 struct regmap *regmap;22 struct nvmem_config sdam_config;23 unsigned int base;24 unsigned int size;25};26 27/* read only register offsets */28static const u8 sdam_ro_map[] = {29 REGISTER_MAP_ID,30 REGISTER_MAP_VERSION,31 SDAM_SIZE32};33 34static bool sdam_is_valid(struct sdam_chip *sdam, unsigned int offset,35 size_t len)36{37 unsigned int sdam_mem_end = SDAM_MEM_START + sdam->size - 1;38 39 if (!len)40 return false;41 42 if (offset >= SDAM_MEM_START && offset <= sdam_mem_end43 && (offset + len - 1) <= sdam_mem_end)44 return true;45 else if ((offset == SDAM_PBS_TRIG_SET || offset == SDAM_PBS_TRIG_CLR)46 && (len == 1))47 return true;48 49 return false;50}51 52static bool sdam_is_ro(unsigned int offset, size_t len)53{54 int i;55 56 for (i = 0; i < ARRAY_SIZE(sdam_ro_map); i++)57 if (offset <= sdam_ro_map[i] && (offset + len) > sdam_ro_map[i])58 return true;59 60 return false;61}62 63static int sdam_read(void *priv, unsigned int offset, void *val,64 size_t bytes)65{66 struct sdam_chip *sdam = priv;67 struct device *dev = sdam->sdam_config.dev;68 int rc;69 70 if (!sdam_is_valid(sdam, offset, bytes)) {71 dev_err(dev, "Invalid SDAM offset %#x len=%zd\n",72 offset, bytes);73 return -EINVAL;74 }75 76 rc = regmap_bulk_read(sdam->regmap, sdam->base + offset, val, bytes);77 if (rc < 0)78 dev_err(dev, "Failed to read SDAM offset %#x len=%zd, rc=%d\n",79 offset, bytes, rc);80 81 return rc;82}83 84static int sdam_write(void *priv, unsigned int offset, void *val,85 size_t bytes)86{87 struct sdam_chip *sdam = priv;88 struct device *dev = sdam->sdam_config.dev;89 int rc;90 91 if (!sdam_is_valid(sdam, offset, bytes)) {92 dev_err(dev, "Invalid SDAM offset %#x len=%zd\n",93 offset, bytes);94 return -EINVAL;95 }96 97 if (sdam_is_ro(offset, bytes)) {98 dev_err(dev, "Invalid write offset %#x len=%zd\n",99 offset, bytes);100 return -EINVAL;101 }102 103 rc = regmap_bulk_write(sdam->regmap, sdam->base + offset, val, bytes);104 if (rc < 0)105 dev_err(dev, "Failed to write SDAM offset %#x len=%zd, rc=%d\n",106 offset, bytes, rc);107 108 return rc;109}110 111static int sdam_probe(struct platform_device *pdev)112{113 struct sdam_chip *sdam;114 struct nvmem_device *nvmem;115 unsigned int val;116 int rc;117 118 sdam = devm_kzalloc(&pdev->dev, sizeof(*sdam), GFP_KERNEL);119 if (!sdam)120 return -ENOMEM;121 122 sdam->regmap = dev_get_regmap(pdev->dev.parent, NULL);123 if (!sdam->regmap) {124 dev_err(&pdev->dev, "Failed to get regmap handle\n");125 return -ENXIO;126 }127 128 rc = of_property_read_u32(pdev->dev.of_node, "reg", &sdam->base);129 if (rc < 0) {130 dev_err(&pdev->dev, "Failed to get SDAM base, rc=%d\n", rc);131 return -EINVAL;132 }133 134 rc = regmap_read(sdam->regmap, sdam->base + SDAM_SIZE, &val);135 if (rc < 0) {136 dev_err(&pdev->dev, "Failed to read SDAM_SIZE rc=%d\n", rc);137 return -EINVAL;138 }139 sdam->size = val * 32;140 141 sdam->sdam_config.dev = &pdev->dev;142 sdam->sdam_config.name = "spmi_sdam";143 sdam->sdam_config.id = NVMEM_DEVID_AUTO;144 sdam->sdam_config.owner = THIS_MODULE;145 sdam->sdam_config.add_legacy_fixed_of_cells = true;146 sdam->sdam_config.stride = 1;147 sdam->sdam_config.word_size = 1;148 sdam->sdam_config.reg_read = sdam_read;149 sdam->sdam_config.reg_write = sdam_write;150 sdam->sdam_config.priv = sdam;151 152 nvmem = devm_nvmem_register(&pdev->dev, &sdam->sdam_config);153 if (IS_ERR(nvmem)) {154 dev_err(&pdev->dev,155 "Failed to register SDAM nvmem device rc=%ld\n",156 PTR_ERR(nvmem));157 return -ENXIO;158 }159 dev_dbg(&pdev->dev,160 "SDAM base=%#x size=%u registered successfully\n",161 sdam->base, sdam->size);162 163 return 0;164}165 166static const struct of_device_id sdam_match_table[] = {167 { .compatible = "qcom,spmi-sdam" },168 {},169};170MODULE_DEVICE_TABLE(of, sdam_match_table);171 172static struct platform_driver sdam_driver = {173 .driver = {174 .name = "qcom,spmi-sdam",175 .of_match_table = sdam_match_table,176 },177 .probe = sdam_probe,178};179module_platform_driver(sdam_driver);180 181MODULE_DESCRIPTION("QCOM SPMI SDAM driver");182MODULE_LICENSE("GPL v2");183