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");
168