xref: /openbmc/u-boot/drivers/i2c/cros_ec_ldo.c (revision 8729d582)
1 /*
2  * Copyright (c) 2015 Google, Inc
3  * Written by Simon Glass <sjg@chromium.org>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <dm.h>
10 #include <cros_ec.h>
11 #include <errno.h>
12 #include <i2c.h>
13 #include <power/tps65090.h>
14 
15 static int cros_ec_ldo_set_bus_speed(struct udevice *dev, unsigned int speed)
16 {
17 	return 0;
18 }
19 
20 static int cros_ec_ldo_xfer(struct udevice *dev, struct i2c_msg *msg,
21 			    int nmsgs)
22 {
23 	bool is_read = nmsgs > 1;
24 	int fet_id, ret;
25 
26 	/*
27 	 * Look for reads and writes of the LDO registers. In either case the
28 	 * first message is a write with the register number as the first byte.
29 	 */
30 	if (!nmsgs || !msg->len || (msg->flags & I2C_M_RD)) {
31 		debug("%s: Invalid message\n", __func__);
32 		goto err;
33 	}
34 
35 	fet_id = msg->buf[0] - REG_FET_BASE;
36 	if (fet_id < 1 || fet_id > MAX_FET_NUM) {
37 		debug("%s: Invalid FET %d\n", __func__, fet_id);
38 		goto err;
39 	}
40 
41 	if (is_read) {
42 		uint8_t state;
43 
44 		ret = cros_ec_get_ldo(dev->parent, fet_id, &state);
45 		if (!ret)
46 			msg[1].buf[0] = state ?
47 				FET_CTRL_ENFET | FET_CTRL_PGFET : 0;
48 	} else {
49 		bool on = msg->buf[1] & FET_CTRL_ENFET;
50 
51 		ret = cros_ec_set_ldo(dev->parent, fet_id, on);
52 	}
53 
54 	return ret;
55 
56 err:
57 	/* Indicate that the message is unimplemented */
58 	return -ENOSYS;
59 }
60 
61 static const struct dm_i2c_ops cros_ec_i2c_ops = {
62 	.xfer		= cros_ec_ldo_xfer,
63 	.set_bus_speed	= cros_ec_ldo_set_bus_speed,
64 };
65 
66 static const struct udevice_id cros_ec_i2c_ids[] = {
67 	{ .compatible = "google,cros-ec-ldo-tunnel" },
68 	{ }
69 };
70 
71 U_BOOT_DRIVER(cros_ec_ldo) = {
72 	.name	= "cros_ec_ldo_tunnel",
73 	.id	= UCLASS_I2C,
74 	.of_match = cros_ec_i2c_ids,
75 	.per_child_auto_alloc_size = sizeof(struct dm_i2c_chip),
76 	.ops	= &cros_ec_i2c_ops,
77 };
78