1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2017, 2020 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/of_platform.h> 10 #include <linux/nvmem-provider.h> 11 #include <linux/regmap.h> 12 13 #define SDAM_MEM_START 0x40 14 #define REGISTER_MAP_ID 0x40 15 #define REGISTER_MAP_VERSION 0x41 16 #define SDAM_SIZE 0x44 17 #define SDAM_PBS_TRIG_SET 0xE5 18 #define SDAM_PBS_TRIG_CLR 0xE6 19 20 struct sdam_chip { 21 struct platform_device *pdev; 22 struct regmap *regmap; 23 struct nvmem_config sdam_config; 24 unsigned int base; 25 unsigned int size; 26 }; 27 28 /* read only register offsets */ 29 static const u8 sdam_ro_map[] = { 30 REGISTER_MAP_ID, 31 REGISTER_MAP_VERSION, 32 SDAM_SIZE 33 }; 34 35 static bool sdam_is_valid(struct sdam_chip *sdam, unsigned int offset, 36 size_t len) 37 { 38 unsigned int sdam_mem_end = SDAM_MEM_START + sdam->size - 1; 39 40 if (!len) 41 return false; 42 43 if (offset >= SDAM_MEM_START && offset <= sdam_mem_end 44 && (offset + len - 1) <= sdam_mem_end) 45 return true; 46 else if ((offset == SDAM_PBS_TRIG_SET || offset == SDAM_PBS_TRIG_CLR) 47 && (len == 1)) 48 return true; 49 50 return false; 51 } 52 53 static bool sdam_is_ro(unsigned int offset, size_t len) 54 { 55 int i; 56 57 for (i = 0; i < ARRAY_SIZE(sdam_ro_map); i++) 58 if (offset <= sdam_ro_map[i] && (offset + len) > sdam_ro_map[i]) 59 return true; 60 61 return false; 62 } 63 64 static int sdam_read(void *priv, unsigned int offset, void *val, 65 size_t bytes) 66 { 67 struct sdam_chip *sdam = priv; 68 struct device *dev = &sdam->pdev->dev; 69 int rc; 70 71 if (!sdam_is_valid(sdam, offset, bytes)) { 72 dev_err(dev, "Invalid SDAM offset %#x len=%zd\n", 73 offset, bytes); 74 return -EINVAL; 75 } 76 77 rc = regmap_bulk_read(sdam->regmap, sdam->base + offset, val, bytes); 78 if (rc < 0) 79 dev_err(dev, "Failed to read SDAM offset %#x len=%zd, rc=%d\n", 80 offset, bytes, rc); 81 82 return rc; 83 } 84 85 static int sdam_write(void *priv, unsigned int offset, void *val, 86 size_t bytes) 87 { 88 struct sdam_chip *sdam = priv; 89 struct device *dev = &sdam->pdev->dev; 90 int rc; 91 92 if (!sdam_is_valid(sdam, offset, bytes)) { 93 dev_err(dev, "Invalid SDAM offset %#x len=%zd\n", 94 offset, bytes); 95 return -EINVAL; 96 } 97 98 if (sdam_is_ro(offset, bytes)) { 99 dev_err(dev, "Invalid write offset %#x len=%zd\n", 100 offset, bytes); 101 return -EINVAL; 102 } 103 104 rc = regmap_bulk_write(sdam->regmap, sdam->base + offset, val, bytes); 105 if (rc < 0) 106 dev_err(dev, "Failed to write SDAM offset %#x len=%zd, rc=%d\n", 107 offset, bytes, rc); 108 109 return rc; 110 } 111 112 static int sdam_probe(struct platform_device *pdev) 113 { 114 struct sdam_chip *sdam; 115 struct nvmem_device *nvmem; 116 unsigned int val; 117 int rc; 118 119 sdam = devm_kzalloc(&pdev->dev, sizeof(*sdam), GFP_KERNEL); 120 if (!sdam) 121 return -ENOMEM; 122 123 sdam->regmap = dev_get_regmap(pdev->dev.parent, NULL); 124 if (!sdam->regmap) { 125 dev_err(&pdev->dev, "Failed to get regmap handle\n"); 126 return -ENXIO; 127 } 128 129 rc = of_property_read_u32(pdev->dev.of_node, "reg", &sdam->base); 130 if (rc < 0) { 131 dev_err(&pdev->dev, "Failed to get SDAM base, rc=%d\n", rc); 132 return -EINVAL; 133 } 134 135 rc = regmap_read(sdam->regmap, sdam->base + SDAM_SIZE, &val); 136 if (rc < 0) { 137 dev_err(&pdev->dev, "Failed to read SDAM_SIZE rc=%d\n", rc); 138 return -EINVAL; 139 } 140 sdam->size = val * 32; 141 142 sdam->sdam_config.dev = &pdev->dev; 143 sdam->sdam_config.name = "spmi_sdam"; 144 sdam->sdam_config.id = NVMEM_DEVID_AUTO; 145 sdam->sdam_config.owner = THIS_MODULE, 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 } 165 166 static const struct of_device_id sdam_match_table[] = { 167 { .compatible = "qcom,spmi-sdam" }, 168 {}, 169 }; 170 171 static struct platform_driver sdam_driver = { 172 .driver = { 173 .name = "qcom,spmi-sdam", 174 .of_match_table = sdam_match_table, 175 }, 176 .probe = sdam_probe, 177 }; 178 179 static int __init sdam_init(void) 180 { 181 return platform_driver_register(&sdam_driver); 182 } 183 subsys_initcall(sdam_init); 184 185 static void __exit sdam_exit(void) 186 { 187 return platform_driver_unregister(&sdam_driver); 188 } 189 module_exit(sdam_exit); 190 191 MODULE_DESCRIPTION("QCOM SPMI SDAM driver"); 192 MODULE_LICENSE("GPL v2"); 193