drivers/nvmem/qfprom.c

   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 static int qfprom_reg_read(void *context,
  21                         unsigned int reg, void *_val, size_t bytes)
  22 {
  23         void __iomem *base = context;
  24         u8 *val = _val;
  25         int i = 0, words = bytes;
  26
  27         while (words--)
  28                 *val++ = readb(base + reg + i++);
  29
  30         return 0;
  31 }
  32
  33 static int qfprom_reg_write(void *context,
  34                          unsigned int reg, void *_val, size_t bytes)
  35 {
  36         void __iomem *base = context;
  37         u8 *val = _val;
  38         int i = 0, words = bytes;
  39
  40         while (words--)
  41                 writeb(*val++, base + reg + i++);
  42
  43         return 0;
  44 }
  45
  46 static int qfprom_remove(struct platform_device *pdev)
  47 {
  48         struct nvmem_device *nvmem = platform_get_drvdata(pdev);
  49
  50         return nvmem_unregister(nvmem);
  51 }
  52
  53 static struct nvmem_config econfig = {
  54         .name = "qfprom",
  55         .owner = THIS_MODULE,
  56         .stride = 1,
  57         .word_size = 1,
  58         .reg_read = qfprom_reg_read,
  59         .reg_write = qfprom_reg_write,
  60 };
  61
  62 static int qfprom_probe(struct platform_device *pdev)
  63 {
  64         struct device *dev = &pdev->dev;
  65         struct resource *res;
  66         struct nvmem_device *nvmem;
  67         void __iomem *base;
  68
  69         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  70         base = devm_ioremap_resource(dev, res);
  71         if (IS_ERR(base))
  72                 return PTR_ERR(base);
  73
  74         econfig.size = resource_size(res);
  75         econfig.dev = dev;
  76         econfig.priv = base;
  77
  78         nvmem = nvmem_register(&econfig);
  79         if (IS_ERR(nvmem))
  80                 return PTR_ERR(nvmem);
  81
  82         platform_set_drvdata(pdev, nvmem);
  83
  84         return 0;
  85 }
  86
  87 static const struct of_device_id qfprom_of_match[] = {
  88         { .compatible = "qcom,qfprom",},
  89         {/* sentinel */},
  90 };
  91 MODULE_DEVICE_TABLE(of, qfprom_of_match);
  92
  93 static struct platform_driver qfprom_driver = {
  94         .probe = qfprom_probe,
  95         .remove = qfprom_remove,
  96         .driver = {
  97                 .name = "qcom,qfprom",
  98                 .of_match_table = qfprom_of_match,
  99         },
 100 };
 101 module_platform_driver(qfprom_driver);
 102 MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org>");
 103 MODULE_DESCRIPTION("Qualcomm QFPROM driver");
 104 MODULE_LICENSE("GPL v2");