diff options
Diffstat (limited to 'roms/u-boot/drivers/i2c/muxes/i2c-mux-gpio.c')
-rw-r--r-- | roms/u-boot/drivers/i2c/muxes/i2c-mux-gpio.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/i2c/muxes/i2c-mux-gpio.c b/roms/u-boot/drivers/i2c/muxes/i2c-mux-gpio.c new file mode 100644 index 000000000..4ca206115 --- /dev/null +++ b/roms/u-boot/drivers/i2c/muxes/i2c-mux-gpio.c @@ -0,0 +1,141 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * I2C multiplexer using GPIO API + * + * Copyright 2017 NXP + * + * Peng Fan <peng.fan@nxp.com> + */ + +#include <asm/global_data.h> +#include <asm/io.h> +#include <asm-generic/gpio.h> +#include <common.h> +#include <dm.h> +#include <dm/device_compat.h> +#include <dm/devres.h> +#include <dm/pinctrl.h> +#include <fdtdec.h> +#include <i2c.h> +#include <linux/errno.h> +#include <linux/libfdt.h> + +DECLARE_GLOBAL_DATA_PTR; + +/** + * struct i2c_mux_gpio_priv - private data for i2c mux gpio + * + * @values: the reg value of each child node + * @n_values: num of regs + * @gpios: the mux-gpios array + * @n_gpios: num of gpios in mux-gpios + * @idle: the value of idle-state + */ +struct i2c_mux_gpio_priv { + u32 *values; + int n_values; + struct gpio_desc *gpios; + int n_gpios; + u32 idle; +}; + + +static int i2c_mux_gpio_select(struct udevice *dev, struct udevice *bus, + uint channel) +{ + struct i2c_mux_gpio_priv *priv = dev_get_priv(dev); + int i, ret; + + for (i = 0; i < priv->n_gpios; i++) { + ret = dm_gpio_set_value(&priv->gpios[i], (channel >> i) & 1); + if (ret) + return ret; + } + + return 0; +} + +static int i2c_mux_gpio_deselect(struct udevice *dev, struct udevice *bus, + uint channel) +{ + struct i2c_mux_gpio_priv *priv = dev_get_priv(dev); + int i, ret; + + for (i = 0; i < priv->n_gpios; i++) { + ret = dm_gpio_set_value(&priv->gpios[i], (priv->idle >> i) & 1); + if (ret) + return ret; + } + + return 0; +} + +static int i2c_mux_gpio_probe(struct udevice *dev) +{ + const void *fdt = gd->fdt_blob; + int node = dev_of_offset(dev); + struct i2c_mux_gpio_priv *mux = dev_get_priv(dev); + struct gpio_desc *gpios; + u32 *values; + int i = 0, subnode, ret; + + mux->n_values = fdtdec_get_child_count(fdt, node); + values = devm_kzalloc(dev, sizeof(*mux->values) * mux->n_values, + GFP_KERNEL); + if (!values) { + dev_err(dev, "Cannot alloc values array"); + return -ENOMEM; + } + + fdt_for_each_subnode(subnode, fdt, node) { + *(values + i) = fdtdec_get_uint(fdt, subnode, "reg", -1); + i++; + } + + mux->values = values; + + mux->idle = fdtdec_get_uint(fdt, node, "idle-state", -1); + + mux->n_gpios = gpio_get_list_count(dev, "mux-gpios"); + if (mux->n_gpios < 0) { + dev_err(dev, "Missing mux-gpios property\n"); + return -EINVAL; + } + + gpios = devm_kzalloc(dev, sizeof(struct gpio_desc) * mux->n_gpios, + GFP_KERNEL); + if (!gpios) { + dev_err(dev, "Cannot allocate gpios array\n"); + return -ENOMEM; + } + + ret = gpio_request_list_by_name(dev, "mux-gpios", gpios, mux->n_gpios, + GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE); + if (ret <= 0) { + dev_err(dev, "Failed to request mux-gpios\n"); + return ret; + } + + mux->gpios = gpios; + + return 0; +} + +static const struct i2c_mux_ops i2c_mux_gpio_ops = { + .select = i2c_mux_gpio_select, + .deselect = i2c_mux_gpio_deselect, +}; + +static const struct udevice_id i2c_mux_gpio_ids[] = { + { .compatible = "i2c-mux-gpio", }, + {} +}; + +U_BOOT_DRIVER(i2c_mux_gpio) = { + .name = "i2c_mux_gpio", + .id = UCLASS_I2C_MUX, + .of_match = i2c_mux_gpio_ids, + .ops = &i2c_mux_gpio_ops, + .probe = i2c_mux_gpio_probe, + .priv_auto = sizeof(struct i2c_mux_gpio_priv), +}; |