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                                         enum tpm_tis_io_mode io_mode)
  40 {
  41         struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
  42         switch (io_mode) {
  43         case TPM_TIS_PHYS_8:
  44                 while (len--)
  45                         *result++ = ioread8(phy->iobase + addr);
  46                 break;
  47         case TPM_TIS_PHYS_16:
  48                 result[1] = ioread8(phy->iobase + addr + 1);
  49                 result[0] = ioread8(phy->iobase + addr);
  50                 break;
  51         case TPM_TIS_PHYS_32:
  52                 result[3] = ioread8(phy->iobase + addr + 3);
  53                 result[2] = ioread8(phy->iobase + addr + 2);
  54                 result[1] = ioread8(phy->iobase + addr + 1);
  55                 result[0] = ioread8(phy->iobase + addr);
  56                 break;
  57         }
  58
  59         return 0;
  60 }
  61
  62 static int tpm_tis_synquacer_write_bytes(struct tpm_tis_data *data, u32 addr,
  63                                          u16 len, const u8 *value,
  64                                          enum tpm_tis_io_mode io_mode)
  65 {
  66         struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
  67         switch (io_mode) {
  68         case TPM_TIS_PHYS_8:
  69                 while (len--)
  70                         iowrite8(*value++, phy->iobase + addr);
  71                 break;
  72         case TPM_TIS_PHYS_16:
  73                 return -EINVAL;
  74         case TPM_TIS_PHYS_32:
  75                 /*
  76                  * Due to the limitation of SPI controller on SynQuacer,
  77                  * 16/32 bits access must be done in byte-wise and descending order.
  78                  */
  79                 iowrite8(value[3], phy->iobase + addr + 3);
  80                 iowrite8(value[2], phy->iobase + addr + 2);
  81                 iowrite8(value[1], phy->iobase + addr + 1);
  82                 iowrite8(value[0], phy->iobase + addr);
  83                 break;
  84         }
  85
  86         return 0;
  87 }
  88
  89 static const struct tpm_tis_phy_ops tpm_tcg_bw = {
  90         .read_bytes     = tpm_tis_synquacer_read_bytes,
  91         .write_bytes    = tpm_tis_synquacer_write_bytes,
  92 };
  93
  94 static int tpm_tis_synquacer_init(struct device *dev,
  95                                   struct tpm_tis_synquacer_info *tpm_info)
  96 {
  97         struct tpm_tis_synquacer_phy *phy;
  98
  99         phy = devm_kzalloc(dev, sizeof(struct tpm_tis_synquacer_phy), GFP_KERNEL);
 100         if (phy == NULL)
 101                 return -ENOMEM;
 102
 103         phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
 104         if (IS_ERR(phy->iobase))
 105                 return PTR_ERR(phy->iobase);
 106
 107         return tpm_tis_core_init(dev, &phy->priv, tpm_info->irq, &tpm_tcg_bw,
 108                                  ACPI_HANDLE(dev));
 109 }
 110
 111 static SIMPLE_DEV_PM_OPS(tpm_tis_synquacer_pm, tpm_pm_suspend, tpm_tis_resume);
 112
 113 static int tpm_tis_synquacer_probe(struct platform_device *pdev)
 114 {
 115         struct tpm_tis_synquacer_info tpm_info = {};
 116         struct resource *res;
 117
 118         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 119         if (res == NULL) {
 120                 dev_err(&pdev->dev, "no memory resource defined\n");
 121                 return -ENODEV;
 122         }
 123         tpm_info.res = *res;
 124
 125         tpm_info.irq = -1;
 126
 127         return tpm_tis_synquacer_init(&pdev->dev, &tpm_info);
 128 }
 129
 130 static void tpm_tis_synquacer_remove(struct platform_device *pdev)
 131 {
 132         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 133
 134         tpm_chip_unregister(chip);
 135         tpm_tis_remove(chip);
 136 }
 137
 138 #ifdef CONFIG_OF
 139 static const struct of_device_id tis_synquacer_of_platform_match[] = {
 140         {.compatible = "socionext,synquacer-tpm-mmio"},
 141         {},
 142 };
 143 MODULE_DEVICE_TABLE(of, tis_synquacer_of_platform_match);
 144 #endif
 145
 146 #ifdef CONFIG_ACPI
 147 static const struct acpi_device_id tpm_synquacer_acpi_tbl[] = {
 148         { "SCX0009" },
 149         {},
 150 };
 151 MODULE_DEVICE_TABLE(acpi, tpm_synquacer_acpi_tbl);
 152 #endif
 153
 154 static struct platform_driver tis_synquacer_drv = {
 155         .probe = tpm_tis_synquacer_probe,
 156         .remove_new = tpm_tis_synquacer_remove,
 157         .driver = {
 158                 .name           = "tpm_tis_synquacer",
 159                 .pm             = &tpm_tis_synquacer_pm,
 160                 .of_match_table = of_match_ptr(tis_synquacer_of_platform_match),
 161                 .acpi_match_table = ACPI_PTR(tpm_synquacer_acpi_tbl),
 162         },
 163 };
 164
 165 static int __init tpm_tis_synquacer_module_init(void)
 166 {
 167         int rc;
 168
 169         rc = platform_driver_register(&tis_synquacer_drv);
 170         if (rc)
 171                 return rc;
 172
 173         return 0;
 174 }
 175
 176 static void __exit tpm_tis_synquacer_module_exit(void)
 177 {
 178         platform_driver_unregister(&tis_synquacer_drv);
 179 }
 180
 181 module_init(tpm_tis_synquacer_module_init);
 182 module_exit(tpm_tis_synquacer_module_exit);
 183 MODULE_DESCRIPTION("TPM MMIO Driver for Socionext SynQuacer platform");
 184 MODULE_LICENSE("GPL");