1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2015 - 2016 Xilinx, Inc.
4 * Copyright (C) 2017 National Instruments Corp
5 * Written by Michal Simek
6 */
7
8 #include <common.h>
9 #include <dm.h>
10 #include <errno.h>
11 #include <i2c.h>
12
13 #include <asm-generic/gpio.h>
14
15 DECLARE_GLOBAL_DATA_PTR;
16
17 enum pca_type {
18 PCA9544,
19 PCA9547,
20 PCA9548,
21 PCA9646
22 };
23
24 struct chip_desc {
25 u8 enable;
26 enum muxtype {
27 pca954x_ismux = 0,
28 pca954x_isswi,
29 } muxtype;
30 u32 width;
31 };
32
33 struct pca954x_priv {
34 u32 addr; /* I2C mux address */
35 u32 width; /* I2C mux width - number of busses */
36 struct gpio_desc gpio_mux_reset;
37 };
38
39 static const struct chip_desc chips[] = {
40 [PCA9544] = {
41 .enable = 0x4,
42 .muxtype = pca954x_ismux,
43 .width = 4,
44 },
45 [PCA9547] = {
46 .enable = 0x8,
47 .muxtype = pca954x_ismux,
48 .width = 8,
49 },
50 [PCA9548] = {
51 .enable = 0x8,
52 .muxtype = pca954x_isswi,
53 .width = 8,
54 },
55 [PCA9646] = {
56 .enable = 0x0,
57 .muxtype = pca954x_isswi,
58 .width = 4,
59 },
60 };
61
pca954x_deselect(struct udevice * mux,struct udevice * bus,uint channel)62 static int pca954x_deselect(struct udevice *mux, struct udevice *bus,
63 uint channel)
64 {
65 struct pca954x_priv *priv = dev_get_priv(mux);
66 uchar byte = 0;
67
68 return dm_i2c_write(mux, priv->addr, &byte, 1);
69 }
70
pca954x_select(struct udevice * mux,struct udevice * bus,uint channel)71 static int pca954x_select(struct udevice *mux, struct udevice *bus,
72 uint channel)
73 {
74 struct pca954x_priv *priv = dev_get_priv(mux);
75 const struct chip_desc *chip = &chips[dev_get_driver_data(mux)];
76 uchar byte;
77
78 if (chip->muxtype == pca954x_ismux)
79 byte = channel | chip->enable;
80 else
81 byte = 1 << channel;
82
83 return dm_i2c_write(mux, priv->addr, &byte, 1);
84 }
85
86 static const struct i2c_mux_ops pca954x_ops = {
87 .select = pca954x_select,
88 .deselect = pca954x_deselect,
89 };
90
91 static const struct udevice_id pca954x_ids[] = {
92 { .compatible = "nxp,pca9544", .data = PCA9544 },
93 { .compatible = "nxp,pca9547", .data = PCA9547 },
94 { .compatible = "nxp,pca9548", .data = PCA9548 },
95 { .compatible = "nxp,pca9646", .data = PCA9646 },
96 { }
97 };
98
pca954x_ofdata_to_platdata(struct udevice * dev)99 static int pca954x_ofdata_to_platdata(struct udevice *dev)
100 {
101 struct pca954x_priv *priv = dev_get_priv(dev);
102 const struct chip_desc *chip = &chips[dev_get_driver_data(dev)];
103
104 priv->addr = dev_read_u32_default(dev, "reg", 0);
105 if (!priv->addr) {
106 debug("MUX not found\n");
107 return -ENODEV;
108 }
109 priv->width = chip->width;
110
111 if (!priv->width) {
112 debug("No I2C MUX width specified\n");
113 return -EINVAL;
114 }
115
116 debug("Device %s at 0x%x with width %d\n",
117 dev->name, priv->addr, priv->width);
118
119 return 0;
120 }
121
pca954x_probe(struct udevice * dev)122 static int pca954x_probe(struct udevice *dev)
123 {
124 if (IS_ENABLED(CONFIG_DM_GPIO)) {
125 struct pca954x_priv *priv = dev_get_priv(dev);
126 int err;
127
128 err = gpio_request_by_name(dev, "reset-gpios", 0,
129 &priv->gpio_mux_reset, GPIOD_IS_OUT);
130
131 /* it's optional so only bail if we get a real error */
132 if (err && (err != -ENOENT))
133 return err;
134
135 /* dm will take care of polarity */
136 if (dm_gpio_is_valid(&priv->gpio_mux_reset))
137 dm_gpio_set_value(&priv->gpio_mux_reset, 0);
138 }
139
140 return 0;
141 }
142
pca954x_remove(struct udevice * dev)143 static int pca954x_remove(struct udevice *dev)
144 {
145 if (IS_ENABLED(CONFIG_DM_GPIO)) {
146 struct pca954x_priv *priv = dev_get_priv(dev);
147
148 if (dm_gpio_is_valid(&priv->gpio_mux_reset))
149 dm_gpio_free(dev, &priv->gpio_mux_reset);
150 }
151
152 return 0;
153 }
154
155 U_BOOT_DRIVER(pca954x) = {
156 .name = "pca954x",
157 .id = UCLASS_I2C_MUX,
158 .of_match = pca954x_ids,
159 .probe = pca954x_probe,
160 .remove = pca954x_remove,
161 .ops = &pca954x_ops,
162 .ofdata_to_platdata = pca954x_ofdata_to_platdata,
163 .priv_auto_alloc_size = sizeof(struct pca954x_priv),
164 };
165