1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2016, NVIDIA CORPORATION.
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <i2c.h>
9 #include <misc.h>
10 #include <asm/arch-tegra/bpmp_abi.h>
11 
12 DECLARE_GLOBAL_DATA_PTR;
13 
14 struct tegra186_bpmp_i2c {
15 	uint32_t bpmp_bus_id;
16 };
17 
18 static inline void serialize_u16(uint8_t **p, uint16_t val)
19 {
20 	(*p)[0] = val & 0xff;
21 	(*p)[1] = val >> 8;
22 	(*p) += 2;
23 }
24 
25 /* These just happen to have the same values as I2C_M_* and SERIALI2C_* */
26 #define SUPPORTED_FLAGS \
27 	(I2C_M_TEN | \
28 	I2C_M_RD | \
29 	I2C_M_STOP | \
30 	I2C_M_NOSTART | \
31 	I2C_M_REV_DIR_ADDR | \
32 	I2C_M_IGNORE_NAK | \
33 	I2C_M_NO_RD_ACK | \
34 	I2C_M_RECV_LEN)
35 
36 static int tegra186_bpmp_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
37 				  int nmsgs)
38 {
39 	struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
40 	struct mrq_i2c_request req;
41 	struct mrq_i2c_response resp;
42 	uint8_t *p;
43 	int left, i, ret;
44 
45 	req.cmd = CMD_I2C_XFER;
46 	req.xfer.bus_id = priv->bpmp_bus_id;
47 	p = &req.xfer.data_buf[0];
48 	left = ARRAY_SIZE(req.xfer.data_buf);
49 	for (i = 0; i < nmsgs; i++) {
50 		int len = 6;
51 		if (!(msg[i].flags & I2C_M_RD))
52 			len += msg[i].len;
53 		if ((len >= BIT(16)) || (len > left))
54 			return -ENOSPC;
55 
56 		if (msg[i].flags & ~SUPPORTED_FLAGS)
57 			return -EINVAL;
58 
59 		serialize_u16(&p, msg[i].addr);
60 		serialize_u16(&p, msg[i].flags);
61 		serialize_u16(&p, msg[i].len);
62 		if (!(msg[i].flags & I2C_M_RD)) {
63 			memcpy(p, msg[i].buf, msg[i].len);
64 			p += msg[i].len;
65 		}
66 	}
67 	req.xfer.data_size = p - &req.xfer.data_buf[0];
68 
69 	ret = misc_call(dev->parent, MRQ_I2C, &req, sizeof(req), &resp,
70 			sizeof(resp));
71 	if (ret < 0)
72 		return ret;
73 
74 	p = &resp.xfer.data_buf[0];
75 	left = resp.xfer.data_size;
76 	if (left > ARRAY_SIZE(resp.xfer.data_buf))
77 		return -EINVAL;
78 	for (i = 0; i < nmsgs; i++) {
79 		if (msg[i].flags & I2C_M_RD) {
80 			memcpy(msg[i].buf, p, msg[i].len);
81 			p += msg[i].len;
82 		}
83 	}
84 
85 	return 0;
86 }
87 
88 static int tegra186_bpmp_i2c_probe(struct udevice *dev)
89 {
90 	struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
91 
92 	priv->bpmp_bus_id = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
93 					    "nvidia,bpmp-bus-id", U32_MAX);
94 	if (priv->bpmp_bus_id == U32_MAX) {
95 		debug("%s: could not parse nvidia,bpmp-bus-id\n", __func__);
96 		return -EINVAL;
97 	}
98 
99 	return 0;
100 }
101 
102 static const struct dm_i2c_ops tegra186_bpmp_i2c_ops = {
103 	.xfer = tegra186_bpmp_i2c_xfer,
104 };
105 
106 static const struct udevice_id tegra186_bpmp_i2c_ids[] = {
107 	{ .compatible = "nvidia,tegra186-bpmp-i2c" },
108 	{ }
109 };
110 
111 U_BOOT_DRIVER(i2c_gpio) = {
112 	.name	= "tegra186_bpmp_i2c",
113 	.id	= UCLASS_I2C,
114 	.of_match = tegra186_bpmp_i2c_ids,
115 	.probe	= tegra186_bpmp_i2c_probe,
116 	.priv_auto_alloc_size = sizeof(struct tegra186_bpmp_i2c),
117 	.ops	= &tegra186_bpmp_i2c_ops,
118 };
119