1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 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 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 regmap *regmap; 22 struct nvmem_config sdam_config; 23 unsigned int base; 24 unsigned int size; 25 }; 26 27 /* read only register offsets */ 28 static const u8 sdam_ro_map[] = { 29 REGISTER_MAP_ID, 30 REGISTER_MAP_VERSION, 31 SDAM_SIZE 32 }; 33 34 static 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_end 43 && (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 52 static 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 63 static 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 84 static 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 } 110 111 static 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.stride = 1; 146 sdam->sdam_config.word_size = 1; 147 sdam->sdam_config.reg_read = sdam_read; 148 sdam->sdam_config.reg_write = sdam_write; 149 sdam->sdam_config.priv = sdam; 150 151 nvmem = devm_nvmem_register(&pdev->dev, &sdam->sdam_config); 152 if (IS_ERR(nvmem)) { 153 dev_err(&pdev->dev, 154 "Failed to register SDAM nvmem device rc=%ld\n", 155 PTR_ERR(nvmem)); 156 return -ENXIO; 157 } 158 dev_dbg(&pdev->dev, 159 "SDAM base=%#x size=%u registered successfully\n", 160 sdam->base, sdam->size); 161 162 return 0; 163 } 164 165 static const struct of_device_id sdam_match_table[] = { 166 { .compatible = "qcom,spmi-sdam" }, 167 {}, 168 }; 169 MODULE_DEVICE_TABLE(of, sdam_match_table); 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 module_platform_driver(sdam_driver); 179 180 MODULE_DESCRIPTION("QCOM SPMI SDAM driver"); 181 MODULE_LICENSE("GPL v2"); 182