1 /* 2 * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 and 6 * only version 2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14 #include <linux/device.h> 15 #include <linux/module.h> 16 #include <linux/io.h> 17 #include <linux/nvmem-provider.h> 18 #include <linux/platform_device.h> 19 20 struct qfprom_priv { 21 void __iomem *base; 22 }; 23 24 static int qfprom_reg_read(void *context, 25 unsigned int reg, void *_val, size_t bytes) 26 { 27 struct qfprom_priv *priv = context; 28 u8 *val = _val; 29 int i = 0, words = bytes; 30 31 while (words--) 32 *val++ = readb(priv->base + reg + i++); 33 34 return 0; 35 } 36 37 static int qfprom_reg_write(void *context, 38 unsigned int reg, void *_val, size_t bytes) 39 { 40 struct qfprom_priv *priv = context; 41 u8 *val = _val; 42 int i = 0, words = bytes; 43 44 while (words--) 45 writeb(*val++, priv->base + reg + i++); 46 47 return 0; 48 } 49 50 static int qfprom_remove(struct platform_device *pdev) 51 { 52 struct nvmem_device *nvmem = platform_get_drvdata(pdev); 53 54 return nvmem_unregister(nvmem); 55 } 56 57 static struct nvmem_config econfig = { 58 .name = "qfprom", 59 .stride = 1, 60 .word_size = 1, 61 .reg_read = qfprom_reg_read, 62 .reg_write = qfprom_reg_write, 63 }; 64 65 static int qfprom_probe(struct platform_device *pdev) 66 { 67 struct device *dev = &pdev->dev; 68 struct resource *res; 69 struct nvmem_device *nvmem; 70 struct qfprom_priv *priv; 71 72 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 73 if (!priv) 74 return -ENOMEM; 75 76 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 77 priv->base = devm_ioremap_resource(dev, res); 78 if (IS_ERR(priv->base)) 79 return PTR_ERR(priv->base); 80 81 econfig.size = resource_size(res); 82 econfig.dev = dev; 83 econfig.priv = priv; 84 85 nvmem = nvmem_register(&econfig); 86 if (IS_ERR(nvmem)) 87 return PTR_ERR(nvmem); 88 89 platform_set_drvdata(pdev, nvmem); 90 91 return 0; 92 } 93 94 static const struct of_device_id qfprom_of_match[] = { 95 { .compatible = "qcom,qfprom",}, 96 {/* sentinel */}, 97 }; 98 MODULE_DEVICE_TABLE(of, qfprom_of_match); 99 100 static struct platform_driver qfprom_driver = { 101 .probe = qfprom_probe, 102 .remove = qfprom_remove, 103 .driver = { 104 .name = "qcom,qfprom", 105 .of_match_table = qfprom_of_match, 106 }, 107 }; 108 module_platform_driver(qfprom_driver); 109 MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org>"); 110 MODULE_DESCRIPTION("Qualcomm QFPROM driver"); 111 MODULE_LICENSE("GPL v2"); 112