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- /*
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 2011, 2012 Cavium, Inc.
- */
- #include <linux/platform_device.h>
- #include <linux/device.h>
- #include <linux/of_mdio.h>
- #include <linux/module.h>
- #include <linux/phy.h>
- #include <linux/mdio-mux.h>
- #include <linux/of_gpio.h>
- #define DRV_VERSION "1.1"
- #define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
- #define MDIO_MUX_GPIO_MAX_BITS 8
- struct mdio_mux_gpio_state {
- struct gpio_desc *gpio[MDIO_MUX_GPIO_MAX_BITS];
- unsigned int num_gpios;
- void *mux_handle;
- };
- static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
- void *data)
- {
- int values[MDIO_MUX_GPIO_MAX_BITS];
- unsigned int n;
- struct mdio_mux_gpio_state *s = data;
- if (current_child == desired_child)
- return 0;
- for (n = 0; n < s->num_gpios; n++) {
- values[n] = (desired_child >> n) & 1;
- }
- gpiod_set_array_cansleep(s->num_gpios, s->gpio, values);
- return 0;
- }
- static int mdio_mux_gpio_probe(struct platform_device *pdev)
- {
- struct mdio_mux_gpio_state *s;
- int num_gpios;
- unsigned int n;
- int r;
- if (!pdev->dev.of_node)
- return -ENODEV;
- num_gpios = of_gpio_count(pdev->dev.of_node);
- if (num_gpios <= 0 || num_gpios > MDIO_MUX_GPIO_MAX_BITS)
- return -ENODEV;
- s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
- if (!s)
- return -ENOMEM;
- s->num_gpios = num_gpios;
- for (n = 0; n < num_gpios; ) {
- struct gpio_desc *gpio = gpiod_get_index(&pdev->dev, NULL, n,
- GPIOD_OUT_LOW);
- if (IS_ERR(gpio)) {
- r = PTR_ERR(gpio);
- goto err;
- }
- s->gpio[n] = gpio;
- n++;
- }
- r = mdio_mux_init(&pdev->dev,
- mdio_mux_gpio_switch_fn, &s->mux_handle, s);
- if (r == 0) {
- pdev->dev.platform_data = s;
- return 0;
- }
- err:
- while (n) {
- n--;
- gpiod_put(s->gpio[n]);
- }
- return r;
- }
- static int mdio_mux_gpio_remove(struct platform_device *pdev)
- {
- unsigned int n;
- struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
- mdio_mux_uninit(s->mux_handle);
- for (n = 0; n < s->num_gpios; n++)
- gpiod_put(s->gpio[n]);
- return 0;
- }
- static const struct of_device_id mdio_mux_gpio_match[] = {
- {
- .compatible = "mdio-mux-gpio",
- },
- {
- /* Legacy compatible property. */
- .compatible = "cavium,mdio-mux-sn74cbtlv3253",
- },
- {},
- };
- MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
- static struct platform_driver mdio_mux_gpio_driver = {
- .driver = {
- .name = "mdio-mux-gpio",
- .of_match_table = mdio_mux_gpio_match,
- },
- .probe = mdio_mux_gpio_probe,
- .remove = mdio_mux_gpio_remove,
- };
- module_platform_driver(mdio_mux_gpio_driver);
- MODULE_DESCRIPTION(DRV_DESCRIPTION);
- MODULE_VERSION(DRV_VERSION);
- MODULE_AUTHOR("David Daney");
- MODULE_LICENSE("GPL");
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