drivers/nvmem/imx-ocotp-scu.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * i.MX8 OCOTP fusebox driver
   4  *
   5  * Copyright 2019 NXP
   6  *
   7  * Peng Fan <peng.fan@nxp.com>
   8  */
   9
  10 #include <linux/firmware/imx/sci.h>
  11 #include <linux/module.h>
  12 #include <linux/nvmem-provider.h>
  13 #include <linux/of_device.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/slab.h>
  16
  17 enum ocotp_devtype {
  18         IMX8QXP,
  19         IMX8QM,
  20 };
  21
  22 struct ocotp_devtype_data {
  23         int devtype;
  24         int nregs;
  25 };
  26
  27 struct ocotp_priv {
  28         struct device *dev;
  29         const struct ocotp_devtype_data *data;
  30         struct imx_sc_ipc *nvmem_ipc;
  31 };
  32
  33 struct imx_sc_msg_misc_fuse_read {
  34         struct imx_sc_rpc_msg hdr;
  35         u32 word;
  36 } __packed;
  37
  38 static struct ocotp_devtype_data imx8qxp_data = {
  39         .devtype = IMX8QXP,
  40         .nregs = 800,
  41 };
  42
  43 static struct ocotp_devtype_data imx8qm_data = {
  44         .devtype = IMX8QM,
  45         .nregs = 800,
  46 };
  47
  48 static int imx_sc_misc_otp_fuse_read(struct imx_sc_ipc *ipc, u32 word,
  49                                      u32 *val)
  50 {
  51         struct imx_sc_msg_misc_fuse_read msg;
  52         struct imx_sc_rpc_msg *hdr = &msg.hdr;
  53         int ret;
  54
  55         hdr->ver = IMX_SC_RPC_VERSION;
  56         hdr->svc = IMX_SC_RPC_SVC_MISC;
  57         hdr->func = IMX_SC_MISC_FUNC_OTP_FUSE_READ;
  58         hdr->size = 2;
  59
  60         msg.word = word;
  61
  62         ret = imx_scu_call_rpc(ipc, &msg, true);
  63         if (ret)
  64                 return ret;
  65
  66         *val = msg.word;
  67
  68         return 0;
  69 }
  70
  71 static int imx_scu_ocotp_read(void *context, unsigned int offset,
  72                               void *val, size_t bytes)
  73 {
  74         struct ocotp_priv *priv = context;
  75         u32 count, index, num_bytes;
  76         u32 *buf;
  77         void *p;
  78         int i, ret;
  79
  80         index = offset >> 2;
  81         num_bytes = round_up((offset % 4) + bytes, 4);
  82         count = num_bytes >> 2;
  83
  84         if (count > (priv->data->nregs - index))
  85                 count = priv->data->nregs - index;
  86
  87         p = kzalloc(num_bytes, GFP_KERNEL);
  88         if (!p)
  89                 return -ENOMEM;
  90
  91         buf = p;
  92
  93         for (i = index; i < (index + count); i++) {
  94                 if (priv->data->devtype == IMX8QXP) {
  95                         if ((i > 271) && (i < 544)) {
  96                                 *buf++ = 0;
  97                                 continue;
  98                         }
  99                 }
 100
 101                 ret = imx_sc_misc_otp_fuse_read(priv->nvmem_ipc, i, buf);
 102                 if (ret) {
 103                         kfree(p);
 104                         return ret;
 105                 }
 106                 buf++;
 107         }
 108
 109         memcpy(val, (u8 *)p + offset % 4, bytes);
 110
 111         kfree(p);
 112
 113         return 0;
 114 }
 115
 116 static struct nvmem_config imx_scu_ocotp_nvmem_config = {
 117         .name = "imx-scu-ocotp",
 118         .read_only = true,
 119         .word_size = 4,
 120         .stride = 1,
 121         .owner = THIS_MODULE,
 122         .reg_read = imx_scu_ocotp_read,
 123 };
 124
 125 static const struct of_device_id imx_scu_ocotp_dt_ids[] = {
 126         { .compatible = "fsl,imx8qxp-scu-ocotp", (void *)&imx8qxp_data },
 127         { .compatible = "fsl,imx8qm-scu-ocotp", (void *)&imx8qm_data },
 128         { },
 129 };
 130 MODULE_DEVICE_TABLE(of, imx_scu_ocotp_dt_ids);
 131
 132 static int imx_scu_ocotp_probe(struct platform_device *pdev)
 133 {
 134         struct device *dev = &pdev->dev;
 135         struct ocotp_priv *priv;
 136         struct nvmem_device *nvmem;
 137         int ret;
 138
 139         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 140         if (!priv)
 141                 return -ENOMEM;
 142
 143         ret = imx_scu_get_handle(&priv->nvmem_ipc);
 144         if (ret)
 145                 return ret;
 146
 147         priv->data = of_device_get_match_data(dev);
 148         priv->dev = dev;
 149         imx_scu_ocotp_nvmem_config.size = 4 * priv->data->nregs;
 150         imx_scu_ocotp_nvmem_config.dev = dev;
 151         imx_scu_ocotp_nvmem_config.priv = priv;
 152         nvmem = devm_nvmem_register(dev, &imx_scu_ocotp_nvmem_config);
 153
 154         return PTR_ERR_OR_ZERO(nvmem);
 155 }
 156
 157 static struct platform_driver imx_scu_ocotp_driver = {
 158         .probe  = imx_scu_ocotp_probe,
 159         .driver = {
 160                 .name   = "imx_scu_ocotp",
 161                 .of_match_table = imx_scu_ocotp_dt_ids,
 162         },
 163 };
 164 module_platform_driver(imx_scu_ocotp_driver);
 165
 166 MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
 167 MODULE_DESCRIPTION("i.MX8 SCU OCOTP fuse box driver");
 168 MODULE_LICENSE("GPL v2");