1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * I2C multiplexer using GPIO API
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * Copyright 2017 NXP
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * Peng Fan <peng.fan@nxp.com>
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * SPDX-License-Identifier: GPL-2.0+
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #include <asm/io.h>
12*4882a593Smuzhiyun #include <asm-generic/gpio.h>
13*4882a593Smuzhiyun #include <common.h>
14*4882a593Smuzhiyun #include <dm.h>
15*4882a593Smuzhiyun #include <dm/pinctrl.h>
16*4882a593Smuzhiyun #include <fdtdec.h>
17*4882a593Smuzhiyun #include <i2c.h>
18*4882a593Smuzhiyun #include <linux/errno.h>
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun DECLARE_GLOBAL_DATA_PTR;
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun /**
23*4882a593Smuzhiyun * struct i2c_mux_gpio_priv - private data for i2c mux gpio
24*4882a593Smuzhiyun *
25*4882a593Smuzhiyun * @values: the reg value of each child node
26*4882a593Smuzhiyun * @n_values: num of regs
27*4882a593Smuzhiyun * @gpios: the mux-gpios array
28*4882a593Smuzhiyun * @n_gpios: num of gpios in mux-gpios
29*4882a593Smuzhiyun * @idle: the value of idle-state
30*4882a593Smuzhiyun */
31*4882a593Smuzhiyun struct i2c_mux_gpio_priv {
32*4882a593Smuzhiyun u32 *values;
33*4882a593Smuzhiyun int n_values;
34*4882a593Smuzhiyun struct gpio_desc *gpios;
35*4882a593Smuzhiyun int n_gpios;
36*4882a593Smuzhiyun u32 idle;
37*4882a593Smuzhiyun };
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun
i2c_mux_gpio_select(struct udevice * dev,struct udevice * bus,uint channel)40*4882a593Smuzhiyun static int i2c_mux_gpio_select(struct udevice *dev, struct udevice *bus,
41*4882a593Smuzhiyun uint channel)
42*4882a593Smuzhiyun {
43*4882a593Smuzhiyun struct i2c_mux_gpio_priv *priv = dev_get_priv(dev);
44*4882a593Smuzhiyun int i, ret;
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun for (i = 0; i < priv->n_gpios; i++) {
47*4882a593Smuzhiyun ret = dm_gpio_set_value(&priv->gpios[i], (channel >> i) & 1);
48*4882a593Smuzhiyun if (ret)
49*4882a593Smuzhiyun return ret;
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun return 0;
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun
i2c_mux_gpio_deselect(struct udevice * dev,struct udevice * bus,uint channel)55*4882a593Smuzhiyun static int i2c_mux_gpio_deselect(struct udevice *dev, struct udevice *bus,
56*4882a593Smuzhiyun uint channel)
57*4882a593Smuzhiyun {
58*4882a593Smuzhiyun struct i2c_mux_gpio_priv *priv = dev_get_priv(dev);
59*4882a593Smuzhiyun int i, ret;
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun for (i = 0; i < priv->n_gpios; i++) {
62*4882a593Smuzhiyun ret = dm_gpio_set_value(&priv->gpios[i], (priv->idle >> i) & 1);
63*4882a593Smuzhiyun if (ret)
64*4882a593Smuzhiyun return ret;
65*4882a593Smuzhiyun }
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun return 0;
68*4882a593Smuzhiyun }
69*4882a593Smuzhiyun
i2c_mux_gpio_probe(struct udevice * dev)70*4882a593Smuzhiyun static int i2c_mux_gpio_probe(struct udevice *dev)
71*4882a593Smuzhiyun {
72*4882a593Smuzhiyun const void *fdt = gd->fdt_blob;
73*4882a593Smuzhiyun int node = dev_of_offset(dev);
74*4882a593Smuzhiyun struct i2c_mux_gpio_priv *mux = dev_get_priv(dev);
75*4882a593Smuzhiyun struct gpio_desc *gpios;
76*4882a593Smuzhiyun u32 *values;
77*4882a593Smuzhiyun int i = 0, subnode, ret;
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun mux->n_values = fdtdec_get_child_count(fdt, node);
80*4882a593Smuzhiyun values = devm_kzalloc(dev, sizeof(*mux->values) * mux->n_values,
81*4882a593Smuzhiyun GFP_KERNEL);
82*4882a593Smuzhiyun if (!values) {
83*4882a593Smuzhiyun dev_err(dev, "Cannot alloc values array");
84*4882a593Smuzhiyun return -ENOMEM;
85*4882a593Smuzhiyun }
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun fdt_for_each_subnode(subnode, fdt, node) {
88*4882a593Smuzhiyun *(values + i) = fdtdec_get_uint(fdt, subnode, "reg", -1);
89*4882a593Smuzhiyun i++;
90*4882a593Smuzhiyun }
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun mux->values = values;
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun mux->idle = fdtdec_get_uint(fdt, node, "idle-state", -1);
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun mux->n_gpios = gpio_get_list_count(dev, "mux-gpios");
97*4882a593Smuzhiyun if (mux->n_gpios < 0) {
98*4882a593Smuzhiyun dev_err(dev, "Missing mux-gpios property\n");
99*4882a593Smuzhiyun return -EINVAL;
100*4882a593Smuzhiyun }
101*4882a593Smuzhiyun
102*4882a593Smuzhiyun gpios = devm_kzalloc(dev, sizeof(struct gpio_desc) * mux->n_gpios,
103*4882a593Smuzhiyun GFP_KERNEL);
104*4882a593Smuzhiyun if (!gpios) {
105*4882a593Smuzhiyun dev_err(dev, "Cannot allocate gpios array\n");
106*4882a593Smuzhiyun return -ENOMEM;
107*4882a593Smuzhiyun }
108*4882a593Smuzhiyun
109*4882a593Smuzhiyun ret = gpio_request_list_by_name(dev, "mux-gpios", gpios, mux->n_gpios,
110*4882a593Smuzhiyun GPIOD_IS_OUT_ACTIVE);
111*4882a593Smuzhiyun if (ret <= 0) {
112*4882a593Smuzhiyun dev_err(dev, "Failed to request mux-gpios\n");
113*4882a593Smuzhiyun return ret;
114*4882a593Smuzhiyun }
115*4882a593Smuzhiyun
116*4882a593Smuzhiyun mux->gpios = gpios;
117*4882a593Smuzhiyun
118*4882a593Smuzhiyun return 0;
119*4882a593Smuzhiyun }
120*4882a593Smuzhiyun
121*4882a593Smuzhiyun static const struct i2c_mux_ops i2c_mux_gpio_ops = {
122*4882a593Smuzhiyun .select = i2c_mux_gpio_select,
123*4882a593Smuzhiyun .deselect = i2c_mux_gpio_deselect,
124*4882a593Smuzhiyun };
125*4882a593Smuzhiyun
126*4882a593Smuzhiyun static const struct udevice_id i2c_mux_gpio_ids[] = {
127*4882a593Smuzhiyun { .compatible = "i2c-mux-gpio", },
128*4882a593Smuzhiyun {}
129*4882a593Smuzhiyun };
130*4882a593Smuzhiyun
131*4882a593Smuzhiyun U_BOOT_DRIVER(i2c_mux_gpio) = {
132*4882a593Smuzhiyun .name = "i2c_mux_gpio",
133*4882a593Smuzhiyun .id = UCLASS_I2C_MUX,
134*4882a593Smuzhiyun .of_match = i2c_mux_gpio_ids,
135*4882a593Smuzhiyun .ops = &i2c_mux_gpio_ops,
136*4882a593Smuzhiyun .probe = i2c_mux_gpio_probe,
137*4882a593Smuzhiyun .priv_auto_alloc_size = sizeof(struct i2c_mux_gpio_priv),
138*4882a593Smuzhiyun };
139