1 // SPDX-License-Identifier: GPL-2.0+
3 * I2C multiplexer using GPIO API
7 * Peng Fan <peng.fan@nxp.com>
11 #include <asm-generic/gpio.h>
14 #include <dm/pinctrl.h>
17 #include <linux/errno.h>
19 DECLARE_GLOBAL_DATA_PTR;
22 * struct i2c_mux_gpio_priv - private data for i2c mux gpio
24 * @values: the reg value of each child node
25 * @n_values: num of regs
26 * @gpios: the mux-gpios array
27 * @n_gpios: num of gpios in mux-gpios
28 * @idle: the value of idle-state
30 struct i2c_mux_gpio_priv {
33 struct gpio_desc *gpios;
39 static int i2c_mux_gpio_select(struct udevice *dev, struct udevice *bus,
42 struct i2c_mux_gpio_priv *priv = dev_get_priv(dev);
45 for (i = 0; i < priv->n_gpios; i++) {
46 ret = dm_gpio_set_value(&priv->gpios[i], (channel >> i) & 1);
54 static int i2c_mux_gpio_deselect(struct udevice *dev, struct udevice *bus,
57 struct i2c_mux_gpio_priv *priv = dev_get_priv(dev);
60 for (i = 0; i < priv->n_gpios; i++) {
61 ret = dm_gpio_set_value(&priv->gpios[i], (priv->idle >> i) & 1);
69 static int i2c_mux_gpio_probe(struct udevice *dev)
71 const void *fdt = gd->fdt_blob;
72 int node = dev_of_offset(dev);
73 struct i2c_mux_gpio_priv *mux = dev_get_priv(dev);
74 struct gpio_desc *gpios;
76 int i = 0, subnode, ret;
78 mux->n_values = fdtdec_get_child_count(fdt, node);
79 values = devm_kzalloc(dev, sizeof(*mux->values) * mux->n_values,
82 dev_err(dev, "Cannot alloc values array");
86 fdt_for_each_subnode(subnode, fdt, node) {
87 *(values + i) = fdtdec_get_uint(fdt, subnode, "reg", -1);
93 mux->idle = fdtdec_get_uint(fdt, node, "idle-state", -1);
95 mux->n_gpios = gpio_get_list_count(dev, "mux-gpios");
96 if (mux->n_gpios < 0) {
97 dev_err(dev, "Missing mux-gpios property\n");
101 gpios = devm_kzalloc(dev, sizeof(struct gpio_desc) * mux->n_gpios,
104 dev_err(dev, "Cannot allocate gpios array\n");
108 ret = gpio_request_list_by_name(dev, "mux-gpios", gpios, mux->n_gpios,
109 GPIOD_IS_OUT_ACTIVE);
111 dev_err(dev, "Failed to request mux-gpios\n");
120 static const struct i2c_mux_ops i2c_mux_gpio_ops = {
121 .select = i2c_mux_gpio_select,
122 .deselect = i2c_mux_gpio_deselect,
125 static const struct udevice_id i2c_mux_gpio_ids[] = {
126 { .compatible = "i2c-mux-gpio", },
130 U_BOOT_DRIVER(i2c_mux_gpio) = {
131 .name = "i2c_mux_gpio",
132 .id = UCLASS_I2C_MUX,
133 .of_match = i2c_mux_gpio_ids,
134 .ops = &i2c_mux_gpio_ops,
135 .probe = i2c_mux_gpio_probe,
136 .priv_auto_alloc_size = sizeof(struct i2c_mux_gpio_priv),