drivers/mtd/nand/raw/ingenic/ingenic_ecc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * JZ47xx ECC common code
   4  *
   5  * Copyright (c) 2015 Imagination Technologies
   6  * Author: Alex Smith <alex.smith@imgtec.com>
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/of_platform.h>
  13 #include <linux/platform_device.h>
  14
  15 #include "ingenic_ecc.h"
  16
  17 /**
  18  * ingenic_ecc_calculate() - calculate ECC for a data buffer
  19  * @ecc: ECC device.
  20  * @params: ECC parameters.
  21  * @buf: input buffer with raw data.
  22  * @ecc_code: output buffer with ECC.
  23  *
  24  * Return: 0 on success, -ETIMEDOUT if timed out while waiting for ECC
  25  * controller.
  26  */
  27 int ingenic_ecc_calculate(struct ingenic_ecc *ecc,
  28                           struct ingenic_ecc_params *params,
  29                           const u8 *buf, u8 *ecc_code)
  30 {
  31         return ecc->ops->calculate(ecc, params, buf, ecc_code);
  32 }
  33
  34 /**
  35  * ingenic_ecc_correct() - detect and correct bit errors
  36  * @ecc: ECC device.
  37  * @params: ECC parameters.
  38  * @buf: raw data read from the chip.
  39  * @ecc_code: ECC read from the chip.
  40  *
  41  * Given the raw data and the ECC read from the NAND device, detects and
  42  * corrects errors in the data.
  43  *
  44  * Return: the number of bit errors corrected, -EBADMSG if there are too many
  45  * errors to correct or -ETIMEDOUT if we timed out waiting for the controller.
  46  */
  47 int ingenic_ecc_correct(struct ingenic_ecc *ecc,
  48                         struct ingenic_ecc_params *params,
  49                         u8 *buf, u8 *ecc_code)
  50 {
  51         return ecc->ops->correct(ecc, params, buf, ecc_code);
  52 }
  53
  54 /**
  55  * ingenic_ecc_get() - get the ECC controller device
  56  * @np: ECC device tree node.
  57  *
  58  * Gets the ECC controller device from the specified device tree node. The
  59  * device must be released with ingenic_ecc_release() when it is no longer being
  60  * used.
  61  *
  62  * Return: a pointer to ingenic_ecc, errors are encoded into the pointer.
  63  * PTR_ERR(-EPROBE_DEFER) if the device hasn't been initialised yet.
  64  */
  65 static struct ingenic_ecc *ingenic_ecc_get(struct device_node *np)
  66 {
  67         struct platform_device *pdev;
  68         struct ingenic_ecc *ecc;
  69
  70         pdev = of_find_device_by_node(np);
  71         if (!pdev || !platform_get_drvdata(pdev))
  72                 return ERR_PTR(-EPROBE_DEFER);
  73
  74         get_device(&pdev->dev);
  75
  76         ecc = platform_get_drvdata(pdev);
  77         clk_prepare_enable(ecc->clk);
  78
  79         return ecc;
  80 }
  81
  82 /**
  83  * of_ingenic_ecc_get() - get the ECC controller from a DT node
  84  * @of_node: the node that contains an ecc-engine property.
  85  *
  86  * Get the ecc-engine property from the given device tree
  87  * node and pass it to ingenic_ecc_get to do the work.
  88  *
  89  * Return: a pointer to ingenic_ecc, errors are encoded into the pointer.
  90  * PTR_ERR(-EPROBE_DEFER) if the device hasn't been initialised yet.
  91  */
  92 struct ingenic_ecc *of_ingenic_ecc_get(struct device_node *of_node)
  93 {
  94         struct ingenic_ecc *ecc = NULL;
  95         struct device_node *np;
  96
  97         np = of_parse_phandle(of_node, "ecc-engine", 0);
  98
  99         /*
 100          * If the ecc-engine property is not found, check for the deprecated
 101          * ingenic,bch-controller property
 102          */
 103         if (!np)
 104                 np = of_parse_phandle(of_node, "ingenic,bch-controller", 0);
 105
 106         if (np) {
 107                 ecc = ingenic_ecc_get(np);
 108                 of_node_put(np);
 109         }
 110         return ecc;
 111 }
 112
 113 /**
 114  * ingenic_ecc_release() - release the ECC controller device
 115  * @ecc: ECC device.
 116  */
 117 void ingenic_ecc_release(struct ingenic_ecc *ecc)
 118 {
 119         clk_disable_unprepare(ecc->clk);
 120         put_device(ecc->dev);
 121 }
 122
 123 int ingenic_ecc_probe(struct platform_device *pdev)
 124 {
 125         struct device *dev = &pdev->dev;
 126         struct ingenic_ecc *ecc;
 127         struct resource *res;
 128
 129         ecc = devm_kzalloc(dev, sizeof(*ecc), GFP_KERNEL);
 130         if (!ecc)
 131                 return -ENOMEM;
 132
 133         ecc->ops = device_get_match_data(dev);
 134         if (!ecc->ops)
 135                 return -EINVAL;
 136
 137         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 138         ecc->base = devm_ioremap_resource(dev, res);
 139         if (IS_ERR(ecc->base))
 140                 return PTR_ERR(ecc->base);
 141
 142         ecc->ops->disable(ecc);
 143
 144         ecc->clk = devm_clk_get(dev, NULL);
 145         if (IS_ERR(ecc->clk)) {
 146                 dev_err(dev, "failed to get clock: %ld\n", PTR_ERR(ecc->clk));
 147                 return PTR_ERR(ecc->clk);
 148         }
 149
 150         mutex_init(&ecc->lock);
 151
 152         ecc->dev = dev;
 153         platform_set_drvdata(pdev, ecc);
 154
 155         return 0;
 156 }
 157 EXPORT_SYMBOL(ingenic_ecc_probe);