1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2011, 2012 Cavium, Inc. 4 */ 5 6 #include <linux/device.h> 7 #include <linux/gpio/consumer.h> 8 #include <linux/mdio-mux.h> 9 #include <linux/module.h> 10 #include <linux/of_mdio.h> 11 #include <linux/phy.h> 12 #include <linux/platform_device.h> 13 14 #define DRV_VERSION "1.1" 15 #define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver" 16 17 struct mdio_mux_gpio_state { 18 struct gpio_descs *gpios; 19 void *mux_handle; 20 }; 21 22 static int mdio_mux_gpio_switch_fn(int current_child, int desired_child, 23 void *data) 24 { 25 struct mdio_mux_gpio_state *s = data; 26 DECLARE_BITMAP(values, BITS_PER_TYPE(desired_child)); 27 28 if (current_child == desired_child) 29 return 0; 30 31 values[0] = desired_child; 32 33 gpiod_multi_set_value_cansleep(s->gpios, values); 34 35 return 0; 36 } 37 38 static int mdio_mux_gpio_probe(struct platform_device *pdev) 39 { 40 struct mdio_mux_gpio_state *s; 41 struct gpio_descs *gpios; 42 int r; 43 44 gpios = devm_gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW); 45 if (IS_ERR(gpios)) 46 return PTR_ERR(gpios); 47 48 s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL); 49 if (!s) 50 return -ENOMEM; 51 52 s->gpios = gpios; 53 54 r = mdio_mux_init(&pdev->dev, pdev->dev.of_node, 55 mdio_mux_gpio_switch_fn, &s->mux_handle, s, NULL); 56 57 if (r != 0) 58 return r; 59 60 pdev->dev.platform_data = s; 61 return 0; 62 } 63 64 static void mdio_mux_gpio_remove(struct platform_device *pdev) 65 { 66 struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev); 67 mdio_mux_uninit(s->mux_handle); 68 } 69 70 static const struct of_device_id mdio_mux_gpio_match[] = { 71 { 72 .compatible = "mdio-mux-gpio", 73 }, 74 { 75 /* Legacy compatible property. */ 76 .compatible = "cavium,mdio-mux-sn74cbtlv3253", 77 }, 78 {}, 79 }; 80 MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match); 81 82 static struct platform_driver mdio_mux_gpio_driver = { 83 .driver = { 84 .name = "mdio-mux-gpio", 85 .of_match_table = mdio_mux_gpio_match, 86 }, 87 .probe = mdio_mux_gpio_probe, 88 .remove = mdio_mux_gpio_remove, 89 }; 90 91 module_platform_driver(mdio_mux_gpio_driver); 92 93 MODULE_DESCRIPTION(DRV_DESCRIPTION); 94 MODULE_VERSION(DRV_VERSION); 95 MODULE_AUTHOR("David Daney"); 96 MODULE_LICENSE("GPL v2"); 97