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/mod_devicetable.h>
  17 #include <linux/io.h>
  18 #include <linux/nvmem-provider.h>
  19 #include <linux/platform_device.h>
  20
  21 struct qfprom_priv {
  22         void __iomem *base;
  23 };
  24
  25 static int qfprom_reg_read(void *context,
  26                         unsigned int reg, void *_val, size_t bytes)
  27 {
  28         struct qfprom_priv *priv = context;
  29         u8 *val = _val;
  30         int i = 0, words = bytes;
  31
  32         while (words--)
  33                 *val++ = readb(priv->base + reg + i++);
  34
  35         return 0;
  36 }
  37
  38 static int qfprom_reg_write(void *context,
  39                          unsigned int reg, void *_val, size_t bytes)
  40 {
  41         struct qfprom_priv *priv = context;
  42         u8 *val = _val;
  43         int i = 0, words = bytes;
  44
  45         while (words--)
  46                 writeb(*val++, priv->base + reg + i++);
  47
  48         return 0;
  49 }
  50
  51 static struct nvmem_config econfig = {
  52         .name = "qfprom",
  53         .stride = 1,
  54         .word_size = 1,
  55         .reg_read = qfprom_reg_read,
  56         .reg_write = qfprom_reg_write,
  57 };
  58
  59 static int qfprom_probe(struct platform_device *pdev)
  60 {
  61         struct device *dev = &pdev->dev;
  62         struct resource *res;
  63         struct nvmem_device *nvmem;
  64         struct qfprom_priv *priv;
  65
  66         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  67         if (!priv)
  68                 return -ENOMEM;
  69
  70         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  71         priv->base = devm_ioremap_resource(dev, res);
  72         if (IS_ERR(priv->base))
  73                 return PTR_ERR(priv->base);
  74
  75         econfig.size = resource_size(res);
  76         econfig.dev = dev;
  77         econfig.priv = priv;
  78
  79         nvmem = devm_nvmem_register(dev, &econfig);
  80
  81         return PTR_ERR_OR_ZERO(nvmem);
  82 }
  83
  84 static const struct of_device_id qfprom_of_match[] = {
  85         { .compatible = "qcom,qfprom",},
  86         {/* sentinel */},
  87 };
  88 MODULE_DEVICE_TABLE(of, qfprom_of_match);
  89
  90 static struct platform_driver qfprom_driver = {
  91         .probe = qfprom_probe,
  92         .driver = {
  93                 .name = "qcom,qfprom",
  94                 .of_match_table = qfprom_of_match,
  95         },
  96 };
  97 module_platform_driver(qfprom_driver);
  98 MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org>");
  99 MODULE_DESCRIPTION("Qualcomm QFPROM driver");
 100 MODULE_LICENSE("GPL v2");