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 {
40 	struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
41 
42 	while (len--)
43 		*result++ = ioread8(phy->iobase + addr);
44 
45 	return 0;
46 }
47 
48 static int tpm_tis_synquacer_write_bytes(struct tpm_tis_data *data, u32 addr,
49 					 u16 len, const u8 *value)
50 {
51 	struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
52 
53 	while (len--)
54 		iowrite8(*value++, phy->iobase + addr);
55 
56 	return 0;
57 }
58 
59 static int tpm_tis_synquacer_read16_bw(struct tpm_tis_data *data,
60 				       u32 addr, u16 *result)
61 {
62 	struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
63 
64 	/*
65 	 * Due to the limitation of SPI controller on SynQuacer,
66 	 * 16/32 bits access must be done in byte-wise and descending order.
67 	 */
68 	*result = (ioread8(phy->iobase + addr + 1) << 8) |
69 		  (ioread8(phy->iobase + addr));
70 
71 	return 0;
72 }
73 
74 static int tpm_tis_synquacer_read32_bw(struct tpm_tis_data *data,
75 				       u32 addr, u32 *result)
76 {
77 	struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
78 
79 	/*
80 	 * Due to the limitation of SPI controller on SynQuacer,
81 	 * 16/32 bits access must be done in byte-wise and descending order.
82 	 */
83 	*result = (ioread8(phy->iobase + addr + 3) << 24) |
84 		  (ioread8(phy->iobase + addr + 2) << 16) |
85 		  (ioread8(phy->iobase + addr + 1) << 8) |
86 		  (ioread8(phy->iobase + addr));
87 
88 	return 0;
89 }
90 
91 static int tpm_tis_synquacer_write32_bw(struct tpm_tis_data *data,
92 					u32 addr, u32 value)
93 {
94 	struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
95 
96 	/*
97 	 * Due to the limitation of SPI controller on SynQuacer,
98 	 * 16/32 bits access must be done in byte-wise and descending order.
99 	 */
100 	iowrite8(value >> 24, phy->iobase + addr + 3);
101 	iowrite8(value >> 16, phy->iobase + addr + 2);
102 	iowrite8(value >> 8, phy->iobase + addr + 1);
103 	iowrite8(value, phy->iobase + addr);
104 
105 	return 0;
106 }
107 
108 static const struct tpm_tis_phy_ops tpm_tcg_bw = {
109 	.read_bytes	= tpm_tis_synquacer_read_bytes,
110 	.write_bytes	= tpm_tis_synquacer_write_bytes,
111 	.read16		= tpm_tis_synquacer_read16_bw,
112 	.read32		= tpm_tis_synquacer_read32_bw,
113 	.write32	= tpm_tis_synquacer_write32_bw,
114 };
115 
116 static int tpm_tis_synquacer_init(struct device *dev,
117 				  struct tpm_tis_synquacer_info *tpm_info)
118 {
119 	struct tpm_tis_synquacer_phy *phy;
120 
121 	phy = devm_kzalloc(dev, sizeof(struct tpm_tis_synquacer_phy), GFP_KERNEL);
122 	if (phy == NULL)
123 		return -ENOMEM;
124 
125 	phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
126 	if (IS_ERR(phy->iobase))
127 		return PTR_ERR(phy->iobase);
128 
129 	return tpm_tis_core_init(dev, &phy->priv, tpm_info->irq, &tpm_tcg_bw,
130 				 ACPI_HANDLE(dev));
131 }
132 
133 static SIMPLE_DEV_PM_OPS(tpm_tis_synquacer_pm, tpm_pm_suspend, tpm_tis_resume);
134 
135 static int tpm_tis_synquacer_probe(struct platform_device *pdev)
136 {
137 	struct tpm_tis_synquacer_info tpm_info = {};
138 	struct resource *res;
139 
140 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
141 	if (res == NULL) {
142 		dev_err(&pdev->dev, "no memory resource defined\n");
143 		return -ENODEV;
144 	}
145 	tpm_info.res = *res;
146 
147 	tpm_info.irq = -1;
148 
149 	return tpm_tis_synquacer_init(&pdev->dev, &tpm_info);
150 }
151 
152 static int tpm_tis_synquacer_remove(struct platform_device *pdev)
153 {
154 	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
155 
156 	tpm_chip_unregister(chip);
157 	tpm_tis_remove(chip);
158 
159 	return 0;
160 }
161 
162 #ifdef CONFIG_OF
163 static const struct of_device_id tis_synquacer_of_platform_match[] = {
164 	{.compatible = "socionext,synquacer-tpm-mmio"},
165 	{},
166 };
167 MODULE_DEVICE_TABLE(of, tis_synquacer_of_platform_match);
168 #endif
169 
170 #ifdef CONFIG_ACPI
171 static const struct acpi_device_id tpm_synquacer_acpi_tbl[] = {
172 	{ "SCX0009" },
173 	{},
174 };
175 MODULE_DEVICE_TABLE(acpi, tpm_synquacer_acpi_tbl);
176 #endif
177 
178 static struct platform_driver tis_synquacer_drv = {
179 	.probe = tpm_tis_synquacer_probe,
180 	.remove = tpm_tis_synquacer_remove,
181 	.driver = {
182 		.name		= "tpm_tis_synquacer",
183 		.pm		= &tpm_tis_synquacer_pm,
184 		.of_match_table = of_match_ptr(tis_synquacer_of_platform_match),
185 		.acpi_match_table = ACPI_PTR(tpm_synquacer_acpi_tbl),
186 	},
187 };
188 
189 static int __init tpm_tis_synquacer_module_init(void)
190 {
191 	int rc;
192 
193 	rc = platform_driver_register(&tis_synquacer_drv);
194 	if (rc)
195 		return rc;
196 
197 	return 0;
198 }
199 
200 static void __exit tpm_tis_synquacer_module_exit(void)
201 {
202 	platform_driver_unregister(&tis_synquacer_drv);
203 }
204 
205 module_init(tpm_tis_synquacer_module_init);
206 module_exit(tpm_tis_synquacer_module_exit);
207 MODULE_DESCRIPTION("TPM MMIO Driver for Socionext SynQuacer platform");
208 MODULE_LICENSE("GPL");
209