drivers/char/tpm/tpm_tis_synquacer.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2020 Linaro Ltd.
   4  *
   5  * This device driver implements MMIO TPM on SynQuacer Platform.
   6  */
   7 #include <linux/acpi.h>
   8 #include <linux/init.h>
   9 #include <linux/module.h>
  10 #include <linux/slab.h>
  11 #include <linux/of.h>
  12 #include <linux/of_device.h>
  13 #include <linux/kernel.h>
  14 #include "tpm.h"
  15 #include "tpm_tis_core.h"
  16
  17 /*
  18  * irq > 0 means: use irq $irq;
  19  * irq = 0 means: autoprobe for an irq;
  20  * irq = -1 means: no irq support
  21  */
  22 struct tpm_tis_synquacer_info {
  23         struct resource res;
  24         int irq;
  25 };
  26
  27 struct tpm_tis_synquacer_phy {
  28         struct tpm_tis_data priv;
  29         void __iomem *iobase;
  30 };
  31
  32 static inline struct tpm_tis_synquacer_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
  33 {
  34         return container_of(data, struct tpm_tis_synquacer_phy, priv);
  35 }
  36
  37 static int tpm_tis_synquacer_read_bytes(struct tpm_tis_data *data, u32 addr,
  38                                         u16 len, u8 *result)
  39 {
  40         struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
  41
  42         while (len--)
  43                 *result++ = ioread8(phy->iobase + addr);
  44
  45         return 0;
  46 }
  47
  48 static int tpm_tis_synquacer_write_bytes(struct tpm_tis_data *data, u32 addr,
  49                                          u16 len, const u8 *value)
  50 {
  51         struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
  52
  53         while (len--)
  54                 iowrite8(*value++, phy->iobase + addr);
  55
  56         return 0;
  57 }
  58
  59 static int tpm_tis_synquacer_read16_bw(struct tpm_tis_data *data,
  60                                        u32 addr, u16 *result)
  61 {
  62         struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
  63
  64         /*
  65          * Due to the limitation of SPI controller on SynQuacer,
  66          * 16/32 bits access must be done in byte-wise and descending order.
  67          */
  68         *result = (ioread8(phy->iobase + addr + 1) << 8) |
  69                   (ioread8(phy->iobase + addr));
  70
  71         return 0;
  72 }
  73
  74 static int tpm_tis_synquacer_read32_bw(struct tpm_tis_data *data,
  75                                        u32 addr, u32 *result)
  76 {
  77         struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
  78
  79         /*
  80          * Due to the limitation of SPI controller on SynQuacer,
  81          * 16/32 bits access must be done in byte-wise and descending order.
  82          */
  83         *result = (ioread8(phy->iobase + addr + 3) << 24) |
  84                   (ioread8(phy->iobase + addr + 2) << 16) |
  85                   (ioread8(phy->iobase + addr + 1) << 8) |
  86                   (ioread8(phy->iobase + addr));
  87
  88         return 0;
  89 }
  90
  91 static int tpm_tis_synquacer_write32_bw(struct tpm_tis_data *data,
  92                                         u32 addr, u32 value)
  93 {
  94         struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
  95
  96         /*
  97          * Due to the limitation of SPI controller on SynQuacer,
  98          * 16/32 bits access must be done in byte-wise and descending order.
  99          */
 100         iowrite8(value >> 24, phy->iobase + addr + 3);
 101         iowrite8(value >> 16, phy->iobase + addr + 2);
 102         iowrite8(value >> 8, phy->iobase + addr + 1);
 103         iowrite8(value, phy->iobase + addr);
 104
 105         return 0;
 106 }
 107
 108 static const struct tpm_tis_phy_ops tpm_tcg_bw = {
 109         .read_bytes     = tpm_tis_synquacer_read_bytes,
 110         .write_bytes    = tpm_tis_synquacer_write_bytes,
 111         .read16         = tpm_tis_synquacer_read16_bw,
 112         .read32         = tpm_tis_synquacer_read32_bw,
 113         .write32        = tpm_tis_synquacer_write32_bw,
 114 };
 115
 116 static int tpm_tis_synquacer_init(struct device *dev,
 117                                   struct tpm_tis_synquacer_info *tpm_info)
 118 {
 119         struct tpm_tis_synquacer_phy *phy;
 120
 121         phy = devm_kzalloc(dev, sizeof(struct tpm_tis_synquacer_phy), GFP_KERNEL);
 122         if (phy == NULL)
 123                 return -ENOMEM;
 124
 125         phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
 126         if (IS_ERR(phy->iobase))
 127                 return PTR_ERR(phy->iobase);
 128
 129         return tpm_tis_core_init(dev, &phy->priv, tpm_info->irq, &tpm_tcg_bw,
 130                                  ACPI_HANDLE(dev));
 131 }
 132
 133 static SIMPLE_DEV_PM_OPS(tpm_tis_synquacer_pm, tpm_pm_suspend, tpm_tis_resume);
 134
 135 static int tpm_tis_synquacer_probe(struct platform_device *pdev)
 136 {
 137         struct tpm_tis_synquacer_info tpm_info = {};
 138         struct resource *res;
 139
 140         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 141         if (res == NULL) {
 142                 dev_err(&pdev->dev, "no memory resource defined\n");
 143                 return -ENODEV;
 144         }
 145         tpm_info.res = *res;
 146
 147         tpm_info.irq = -1;
 148
 149         return tpm_tis_synquacer_init(&pdev->dev, &tpm_info);
 150 }
 151
 152 static int tpm_tis_synquacer_remove(struct platform_device *pdev)
 153 {
 154         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 155
 156         tpm_chip_unregister(chip);
 157         tpm_tis_remove(chip);
 158
 159         return 0;
 160 }
 161
 162 #ifdef CONFIG_OF
 163 static const struct of_device_id tis_synquacer_of_platform_match[] = {
 164         {.compatible = "socionext,synquacer-tpm-mmio"},
 165         {},
 166 };
 167 MODULE_DEVICE_TABLE(of, tis_synquacer_of_platform_match);
 168 #endif
 169
 170 #ifdef CONFIG_ACPI
 171 static const struct acpi_device_id tpm_synquacer_acpi_tbl[] = {
 172         { "SCX0009" },
 173         {},
 174 };
 175 MODULE_DEVICE_TABLE(acpi, tpm_synquacer_acpi_tbl);
 176 #endif
 177
 178 static struct platform_driver tis_synquacer_drv = {
 179         .probe = tpm_tis_synquacer_probe,
 180         .remove = tpm_tis_synquacer_remove,
 181         .driver = {
 182                 .name           = "tpm_tis_synquacer",
 183                 .pm             = &tpm_tis_synquacer_pm,
 184                 .of_match_table = of_match_ptr(tis_synquacer_of_platform_match),
 185                 .acpi_match_table = ACPI_PTR(tpm_synquacer_acpi_tbl),
 186         },
 187 };
 188
 189 static int __init tpm_tis_synquacer_module_init(void)
 190 {
 191         int rc;
 192
 193         rc = platform_driver_register(&tis_synquacer_drv);
 194         if (rc)
 195                 return rc;
 196
 197         return 0;
 198 }
 199
 200 static void __exit tpm_tis_synquacer_module_exit(void)
 201 {
 202         platform_driver_unregister(&tis_synquacer_drv);
 203 }
 204
 205 module_init(tpm_tis_synquacer_module_init);
 206 module_exit(tpm_tis_synquacer_module_exit);
 207 MODULE_DESCRIPTION("TPM MMIO Driver for Socionext SynQuacer platform");
 208 MODULE_LICENSE("GPL");