xref: /openbmc/u-boot/drivers/i2c/muxes/pca954x.c (revision 77c07e7e)
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