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
to_tpm_tis_tcg_phy(struct tpm_tis_data * data)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
tpm_tis_synquacer_read_bytes(struct tpm_tis_data * data,u32 addr,u16 len,u8 * result,enum tpm_tis_io_mode io_mode)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
tpm_tis_synquacer_write_bytes(struct tpm_tis_data * data,u32 addr,u16 len,const u8 * value,enum tpm_tis_io_mode io_mode)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
tpm_tis_synquacer_init(struct device * dev,struct tpm_tis_synquacer_info * tpm_info)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
tpm_tis_synquacer_probe(struct platform_device * pdev)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
tpm_tis_synquacer_remove(struct platform_device * pdev)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");
168