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/kernel.h>
  13 #include "tpm.h"
  14 #include "tpm_tis_core.h"
  15
  16 /*
  17  * irq > 0 means: use irq $irq;
  18  * irq = 0 means: autoprobe for an irq;
  19  * irq = -1 means: no irq support
  20  */
  21 struct tpm_tis_synquacer_info {
  22         struct resource res;
  23         int irq;
  24 };
  25
  26 struct tpm_tis_synquacer_phy {
  27         struct tpm_tis_data priv;
  28         void __iomem *iobase;
  29 };
  30
  31 static inline struct tpm_tis_synquacer_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
  32 {
  33         return container_of(data, struct tpm_tis_synquacer_phy, priv);
  34 }
  35
  36 static int tpm_tis_synquacer_read_bytes(struct tpm_tis_data *data, u32 addr,
  37                                         u16 len, u8 *result,
  38                                         enum tpm_tis_io_mode io_mode)
  39 {
  40         struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
  41         switch (io_mode) {
  42         case TPM_TIS_PHYS_8:
  43                 while (len--)
  44                         *result++ = ioread8(phy->iobase + addr);
  45                 break;
  46         case TPM_TIS_PHYS_16:
  47                 result[1] = ioread8(phy->iobase + addr + 1);
  48                 result[0] = ioread8(phy->iobase + addr);
  49                 break;
  50         case TPM_TIS_PHYS_32:
  51                 result[3] = ioread8(phy->iobase + addr + 3);
  52                 result[2] = ioread8(phy->iobase + addr + 2);
  53                 result[1] = ioread8(phy->iobase + addr + 1);
  54                 result[0] = ioread8(phy->iobase + addr);
  55                 break;
  56         }
  57
  58         return 0;
  59 }
  60
  61 static int tpm_tis_synquacer_write_bytes(struct tpm_tis_data *data, u32 addr,
  62                                          u16 len, const u8 *value,
  63                                          enum tpm_tis_io_mode io_mode)
  64 {
  65         struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
  66         switch (io_mode) {
  67         case TPM_TIS_PHYS_8:
  68                 while (len--)
  69                         iowrite8(*value++, phy->iobase + addr);
  70                 break;
  71         case TPM_TIS_PHYS_16:
  72                 return -EINVAL;
  73         case TPM_TIS_PHYS_32:
  74                 /*
  75                  * Due to the limitation of SPI controller on SynQuacer,
  76                  * 16/32 bits access must be done in byte-wise and descending order.
  77                  */
  78                 iowrite8(value[3], phy->iobase + addr + 3);
  79                 iowrite8(value[2], phy->iobase + addr + 2);
  80                 iowrite8(value[1], phy->iobase + addr + 1);
  81                 iowrite8(value[0], phy->iobase + addr);
  82                 break;
  83         }
  84
  85         return 0;
  86 }
  87
  88 static const struct tpm_tis_phy_ops tpm_tcg_bw = {
  89         .read_bytes     = tpm_tis_synquacer_read_bytes,
  90         .write_bytes    = tpm_tis_synquacer_write_bytes,
  91 };
  92
  93 static int tpm_tis_synquacer_init(struct device *dev,
  94                                   struct tpm_tis_synquacer_info *tpm_info)
  95 {
  96         struct tpm_tis_synquacer_phy *phy;
  97
  98         phy = devm_kzalloc(dev, sizeof(struct tpm_tis_synquacer_phy), GFP_KERNEL);
  99         if (phy == NULL)
 100                 return -ENOMEM;
 101
 102         phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
 103         if (IS_ERR(phy->iobase))
 104                 return PTR_ERR(phy->iobase);
 105
 106         return tpm_tis_core_init(dev, &phy->priv, tpm_info->irq, &tpm_tcg_bw,
 107                                  ACPI_HANDLE(dev));
 108 }
 109
 110 static SIMPLE_DEV_PM_OPS(tpm_tis_synquacer_pm, tpm_pm_suspend, tpm_tis_resume);
 111
 112 static int tpm_tis_synquacer_probe(struct platform_device *pdev)
 113 {
 114         struct tpm_tis_synquacer_info tpm_info = {};
 115         struct resource *res;
 116
 117         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 118         if (res == NULL) {
 119                 dev_err(&pdev->dev, "no memory resource defined\n");
 120                 return -ENODEV;
 121         }
 122         tpm_info.res = *res;
 123
 124         tpm_info.irq = -1;
 125
 126         return tpm_tis_synquacer_init(&pdev->dev, &tpm_info);
 127 }
 128
 129 static void tpm_tis_synquacer_remove(struct platform_device *pdev)
 130 {
 131         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 132
 133         tpm_chip_unregister(chip);
 134         tpm_tis_remove(chip);
 135 }
 136
 137 #ifdef CONFIG_OF
 138 static const struct of_device_id tis_synquacer_of_platform_match[] = {
 139         {.compatible = "socionext,synquacer-tpm-mmio"},
 140         {},
 141 };
 142 MODULE_DEVICE_TABLE(of, tis_synquacer_of_platform_match);
 143 #endif
 144
 145 #ifdef CONFIG_ACPI
 146 static const struct acpi_device_id tpm_synquacer_acpi_tbl[] = {
 147         { "SCX0009" },
 148         {},
 149 };
 150 MODULE_DEVICE_TABLE(acpi, tpm_synquacer_acpi_tbl);
 151 #endif
 152
 153 static struct platform_driver tis_synquacer_drv = {
 154         .probe = tpm_tis_synquacer_probe,
 155         .remove_new = tpm_tis_synquacer_remove,
 156         .driver = {
 157                 .name           = "tpm_tis_synquacer",
 158                 .pm             = &tpm_tis_synquacer_pm,
 159                 .of_match_table = of_match_ptr(tis_synquacer_of_platform_match),
 160                 .acpi_match_table = ACPI_PTR(tpm_synquacer_acpi_tbl),
 161         },
 162 };
 163
 164 module_platform_driver(tis_synquacer_drv);
 165
 166 MODULE_DESCRIPTION("TPM MMIO Driver for Socionext SynQuacer platform");
 167 MODULE_LICENSE("GPL");