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83d290c5 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
bcd5dfff SG |
2 | /* |
3 | * Copyright (C) 2015 Google, Inc | |
4 | * Written by Simon Glass <sjg@chromium.org> | |
bcd5dfff SG |
5 | */ |
6 | ||
d678a59d | 7 | #include <common.h> |
bcd5dfff SG |
8 | #include <dm.h> |
9 | #include <errno.h> | |
10 | #include <i2c.h> | |
f7ae49fc | 11 | #include <log.h> |
bcd5dfff | 12 | #include <video_bridge.h> |
401d1c4f | 13 | #include <asm/global_data.h> |
c05ed00a | 14 | #include <linux/delay.h> |
bcd5dfff SG |
15 | #include <power/regulator.h> |
16 | ||
17 | DECLARE_GLOBAL_DATA_PTR; | |
18 | ||
19 | /* | |
20 | * Initialisation of the chip is a process of writing certain values into | |
21 | * certain registers over i2c bus. The chip in fact responds to a range of | |
22 | * addresses on the i2c bus, so for each written value three parameters are | |
23 | * required: i2c address, register address and the actual value. | |
24 | * | |
25 | * The base address is derived from the device tree, but oddly the chip | |
26 | * responds on several addresses with different register sets for each. | |
27 | */ | |
28 | ||
29 | /** | |
30 | * ps8622_write() Write a PS8622 eDP bridge i2c register | |
31 | * | |
32 | * @param dev I2C device | |
33 | * @param addr_off offset from the i2c base address for ps8622 | |
34 | * @param reg_addr register address to write | |
35 | * @param value value to be written | |
185f812c | 36 | * Return: 0 on success, non-0 on failure |
bcd5dfff SG |
37 | */ |
38 | static int ps8622_write(struct udevice *dev, unsigned addr_off, | |
39 | unsigned char reg_addr, unsigned char value) | |
40 | { | |
caa4daa2 | 41 | struct dm_i2c_chip *chip = dev_get_parent_plat(dev); |
bcd5dfff SG |
42 | uint8_t buf[2]; |
43 | struct i2c_msg msg; | |
44 | int ret; | |
45 | ||
46 | msg.addr = chip->chip_addr + addr_off; | |
47 | msg.flags = 0; | |
48 | buf[0] = reg_addr; | |
49 | buf[1] = value; | |
50 | msg.buf = buf; | |
51 | msg.len = 2; | |
52 | ret = dm_i2c_xfer(dev, &msg, 1); | |
53 | if (ret) { | |
54 | debug("%s: write failed, reg=%#x, value=%#x, ret=%d\n", | |
55 | __func__, reg_addr, value, ret); | |
56 | return ret; | |
57 | } | |
58 | ||
59 | return 0; | |
60 | } | |
61 | ||
62 | static int ps8622_set_backlight(struct udevice *dev, int percent) | |
63 | { | |
64 | int level = percent * 255 / 100; | |
65 | ||
66 | debug("%s: level=%d\n", __func__, level); | |
67 | return ps8622_write(dev, 0x01, 0xa7, level); | |
68 | } | |
69 | ||
70 | static int ps8622_attach(struct udevice *dev) | |
71 | { | |
72 | const uint8_t *params; | |
73 | struct udevice *reg; | |
74 | int ret, i, len; | |
75 | ||
76 | debug("%s: %s\n", __func__, dev->name); | |
77 | /* set the LDO providing the 1.2V rail to the Parade bridge */ | |
78 | ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev, | |
79 | "power-supply", ®); | |
80 | if (!ret) { | |
81 | ret = regulator_autoset(reg); | |
82 | } else if (ret != -ENOENT) { | |
83 | debug("%s: Failed to enable power: ret=%d\n", __func__, ret); | |
84 | return ret; | |
85 | } | |
86 | ||
87 | ret = video_bridge_set_active(dev, true); | |
88 | if (ret) | |
89 | return ret; | |
90 | ||
e160f7d4 SG |
91 | params = fdt_getprop(gd->fdt_blob, dev_of_offset(dev), "parade,regs", |
92 | &len); | |
bcd5dfff SG |
93 | if (!params || len % 3) { |
94 | debug("%s: missing/invalid params=%p, len=%x\n", __func__, | |
95 | params, len); | |
96 | return -EINVAL; | |
97 | } | |
98 | ||
99 | /* need to wait 20ms after power on before doing I2C writes */ | |
100 | mdelay(20); | |
101 | for (i = 0; i < len; i += 3) { | |
102 | ret = ps8622_write(dev, params[i + 0], params[i + 1], | |
103 | params[i + 2]); | |
104 | if (ret) | |
105 | return ret; | |
106 | } | |
107 | ||
108 | return 0; | |
109 | } | |
110 | ||
111 | static int ps8622_probe(struct udevice *dev) | |
112 | { | |
113 | debug("%s\n", __func__); | |
114 | if (device_get_uclass_id(dev->parent) != UCLASS_I2C) | |
115 | return -EPROTONOSUPPORT; | |
116 | ||
117 | return 0; | |
118 | } | |
119 | ||
120 | struct video_bridge_ops ps8622_ops = { | |
121 | .attach = ps8622_attach, | |
122 | .set_backlight = ps8622_set_backlight, | |
123 | }; | |
124 | ||
125 | static const struct udevice_id ps8622_ids[] = { | |
126 | { .compatible = "parade,ps8622", }, | |
127 | { .compatible = "parade,ps8625", }, | |
128 | { } | |
129 | }; | |
130 | ||
131 | U_BOOT_DRIVER(parade_ps8622) = { | |
132 | .name = "parade_ps8622", | |
133 | .id = UCLASS_VIDEO_BRIDGE, | |
134 | .of_match = ps8622_ids, | |
135 | .probe = ps8622_probe, | |
136 | .ops = &ps8622_ops, | |
137 | }; |