char/tpm/tpm_tis_synquacer.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (C) 2020 Linaro Ltd.
0004  *
0005  * This device driver implements MMIO TPM on SynQuacer Platform.
0006  */
0007 #include <linux/acpi.h>
0008 #include <linux/init.h>
0009 #include <linux/module.h>
0010 #include <linux/slab.h>
0011 #include <linux/of.h>
0012 #include <linux/of_device.h>
0013 #include <linux/kernel.h>
0014 #include "tpm.h"
0015 #include "tpm_tis_core.h"
0016
0017 /*
0018  * irq > 0 means: use irq $irq;
0019  * irq = 0 means: autoprobe for an irq;
0020  * irq = -1 means: no irq support
0021  */
0022 struct tpm_tis_synquacer_info {
0023     struct resource res;
0024     int irq;
0025 };
0026
0027 struct tpm_tis_synquacer_phy {
0028     struct tpm_tis_data priv;
0029     void __iomem *iobase;
0030 };
0031
0032 static inline struct tpm_tis_synquacer_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
0033 {
0034     return container_of(data, struct tpm_tis_synquacer_phy, priv);
0035 }
0036
0037 static int tpm_tis_synquacer_read_bytes(struct tpm_tis_data *data, u32 addr,
0038                     u16 len, u8 *result,
0039                     enum tpm_tis_io_mode io_mode)
0040 {
0041     struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
0042     switch (io_mode) {
0043     case TPM_TIS_PHYS_8:
0044         while (len--)
0045             *result++ = ioread8(phy->iobase + addr);
0046         break;
0047     case TPM_TIS_PHYS_16:
0048         result[1] = ioread8(phy->iobase + addr + 1);
0049         result[0] = ioread8(phy->iobase + addr);
0050         break;
0051     case TPM_TIS_PHYS_32:
0052         result[3] = ioread8(phy->iobase + addr + 3);
0053         result[2] = ioread8(phy->iobase + addr + 2);
0054         result[1] = ioread8(phy->iobase + addr + 1);
0055         result[0] = ioread8(phy->iobase + addr);
0056         break;
0057     }
0058
0059     return 0;
0060 }
0061
0062 static int tpm_tis_synquacer_write_bytes(struct tpm_tis_data *data, u32 addr,
0063                      u16 len, const u8 *value,
0064                      enum tpm_tis_io_mode io_mode)
0065 {
0066     struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
0067     switch (io_mode) {
0068     case TPM_TIS_PHYS_8:
0069         while (len--)
0070             iowrite8(*value++, phy->iobase + addr);
0071         break;
0072     case TPM_TIS_PHYS_16:
0073         return -EINVAL;
0074     case TPM_TIS_PHYS_32:
0075         /*
0076          * Due to the limitation of SPI controller on SynQuacer,
0077          * 16/32 bits access must be done in byte-wise and descending order.
0078          */
0079         iowrite8(value[3], phy->iobase + addr + 3);
0080         iowrite8(value[2], phy->iobase + addr + 2);
0081         iowrite8(value[1], phy->iobase + addr + 1);
0082         iowrite8(value[0], phy->iobase + addr);
0083         break;
0084     }
0085
0086     return 0;
0087 }
0088
0089 static const struct tpm_tis_phy_ops tpm_tcg_bw = {
0090     .read_bytes = tpm_tis_synquacer_read_bytes,
0091     .write_bytes    = tpm_tis_synquacer_write_bytes,
0092 };
0093
0094 static int tpm_tis_synquacer_init(struct device *dev,
0095                   struct tpm_tis_synquacer_info *tpm_info)
0096 {
0097     struct tpm_tis_synquacer_phy *phy;
0098
0099     phy = devm_kzalloc(dev, sizeof(struct tpm_tis_synquacer_phy), GFP_KERNEL);
0100     if (phy == NULL)
0101         return -ENOMEM;
0102
0103     phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
0104     if (IS_ERR(phy->iobase))
0105         return PTR_ERR(phy->iobase);
0106
0107     return tpm_tis_core_init(dev, &phy->priv, tpm_info->irq, &tpm_tcg_bw,
0108                  ACPI_HANDLE(dev));
0109 }
0110
0111 static SIMPLE_DEV_PM_OPS(tpm_tis_synquacer_pm, tpm_pm_suspend, tpm_tis_resume);
0112
0113 static int tpm_tis_synquacer_probe(struct platform_device *pdev)
0114 {
0115     struct tpm_tis_synquacer_info tpm_info = {};
0116     struct resource *res;
0117
0118     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0119     if (res == NULL) {
0120         dev_err(&pdev->dev, "no memory resource defined\n");
0121         return -ENODEV;
0122     }
0123     tpm_info.res = *res;
0124
0125     tpm_info.irq = -1;
0126
0127     return tpm_tis_synquacer_init(&pdev->dev, &tpm_info);
0128 }
0129
0130 static int tpm_tis_synquacer_remove(struct platform_device *pdev)
0131 {
0132     struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
0133
0134     tpm_chip_unregister(chip);
0135     tpm_tis_remove(chip);
0136
0137     return 0;
0138 }
0139
0140 #ifdef CONFIG_OF
0141 static const struct of_device_id tis_synquacer_of_platform_match[] = {
0142     {.compatible = "socionext,synquacer-tpm-mmio"},
0143     {},
0144 };
0145 MODULE_DEVICE_TABLE(of, tis_synquacer_of_platform_match);
0146 #endif
0147
0148 #ifdef CONFIG_ACPI
0149 static const struct acpi_device_id tpm_synquacer_acpi_tbl[] = {
0150     { "SCX0009" },
0151     {},
0152 };
0153 MODULE_DEVICE_TABLE(acpi, tpm_synquacer_acpi_tbl);
0154 #endif
0155
0156 static struct platform_driver tis_synquacer_drv = {
0157     .probe = tpm_tis_synquacer_probe,
0158     .remove = tpm_tis_synquacer_remove,
0159     .driver = {
0160         .name       = "tpm_tis_synquacer",
0161         .pm     = &tpm_tis_synquacer_pm,
0162         .of_match_table = of_match_ptr(tis_synquacer_of_platform_match),
0163         .acpi_match_table = ACPI_PTR(tpm_synquacer_acpi_tbl),
0164     },
0165 };
0166
0167 static int __init tpm_tis_synquacer_module_init(void)
0168 {
0169     int rc;
0170
0171     rc = platform_driver_register(&tis_synquacer_drv);
0172     if (rc)
0173         return rc;
0174
0175     return 0;
0176 }
0177
0178 static void __exit tpm_tis_synquacer_module_exit(void)
0179 {
0180     platform_driver_unregister(&tis_synquacer_drv);
0181 }
0182
0183 module_init(tpm_tis_synquacer_module_init);
0184 module_exit(tpm_tis_synquacer_module_exit);
0185 MODULE_DESCRIPTION("TPM MMIO Driver for Socionext SynQuacer platform");
0186 MODULE_LICENSE("GPL");