drivers/nvmem/qfprom.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
   4  */
   5
   6 #include <linux/device.h>
   7 #include <linux/module.h>
   8 #include <linux/mod_devicetable.h>
   9 #include <linux/io.h>
  10 #include <linux/nvmem-provider.h>
  11 #include <linux/platform_device.h>
  12
  13 struct qfprom_priv {
  14         void __iomem *base;
  15 };
  16
  17 static int qfprom_reg_read(void *context,
  18                         unsigned int reg, void *_val, size_t bytes)
  19 {
  20         struct qfprom_priv *priv = context;
  21         u8 *val = _val;
  22         int i = 0, words = bytes;
  23
  24         while (words--)
  25                 *val++ = readb(priv->base + reg + i++);
  26
  27         return 0;
  28 }
  29
  30 static int qfprom_reg_write(void *context,
  31                          unsigned int reg, void *_val, size_t bytes)
  32 {
  33         struct qfprom_priv *priv = context;
  34         u8 *val = _val;
  35         int i = 0, words = bytes;
  36
  37         while (words--)
  38                 writeb(*val++, priv->base + reg + i++);
  39
  40         return 0;
  41 }
  42
  43 static struct nvmem_config econfig = {
  44         .name = "qfprom",
  45         .stride = 1,
  46         .word_size = 1,
  47         .reg_read = qfprom_reg_read,
  48         .reg_write = qfprom_reg_write,
  49 };
  50
  51 static int qfprom_probe(struct platform_device *pdev)
  52 {
  53         struct device *dev = &pdev->dev;
  54         struct resource *res;
  55         struct nvmem_device *nvmem;
  56         struct qfprom_priv *priv;
  57
  58         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  59         if (!priv)
  60                 return -ENOMEM;
  61
  62         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  63         priv->base = devm_ioremap_resource(dev, res);
  64         if (IS_ERR(priv->base))
  65                 return PTR_ERR(priv->base);
  66
  67         econfig.size = resource_size(res);
  68         econfig.dev = dev;
  69         econfig.priv = priv;
  70
  71         nvmem = devm_nvmem_register(dev, &econfig);
  72
  73         return PTR_ERR_OR_ZERO(nvmem);
  74 }
  75
  76 static const struct of_device_id qfprom_of_match[] = {
  77         { .compatible = "qcom,qfprom",},
  78         {/* sentinel */},
  79 };
  80 MODULE_DEVICE_TABLE(of, qfprom_of_match);
  81
  82 static struct platform_driver qfprom_driver = {
  83         .probe = qfprom_probe,
  84         .driver = {
  85                 .name = "qcom,qfprom",
  86                 .of_match_table = qfprom_of_match,
  87         },
  88 };
  89 module_platform_driver(qfprom_driver);
  90 MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org>");
  91 MODULE_DESCRIPTION("Qualcomm QFPROM driver");
  92 MODULE_LICENSE("GPL v2");