1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2011, 2012 Cavium, Inc. 4 */ 5 6 #include <linux/platform_device.h> 7 #include <linux/device.h> 8 #include <linux/of_mdio.h> 9 #include <linux/module.h> 10 #include <linux/phy.h> 11 #include <linux/mdio-mux.h> 12 #include <linux/gpio/consumer.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_set_array_value_cansleep(s->gpios->ndescs, s->gpios->desc, 34 s->gpios->info, values); 35 36 return 0; 37 } 38 39 static int mdio_mux_gpio_probe(struct platform_device *pdev) 40 { 41 struct mdio_mux_gpio_state *s; 42 struct gpio_descs *gpios; 43 int r; 44 45 gpios = devm_gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW); 46 if (IS_ERR(gpios)) 47 return PTR_ERR(gpios); 48 49 s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL); 50 if (!s) 51 return -ENOMEM; 52 53 s->gpios = gpios; 54 55 r = mdio_mux_init(&pdev->dev, pdev->dev.of_node, 56 mdio_mux_gpio_switch_fn, &s->mux_handle, s, NULL); 57 58 if (r != 0) 59 return r; 60 61 pdev->dev.platform_data = s; 62 return 0; 63 } 64 65 static int mdio_mux_gpio_remove(struct platform_device *pdev) 66 { 67 struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev); 68 mdio_mux_uninit(s->mux_handle); 69 return 0; 70 } 71 72 static const struct of_device_id mdio_mux_gpio_match[] = { 73 { 74 .compatible = "mdio-mux-gpio", 75 }, 76 { 77 /* Legacy compatible property. */ 78 .compatible = "cavium,mdio-mux-sn74cbtlv3253", 79 }, 80 {}, 81 }; 82 MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match); 83 84 static struct platform_driver mdio_mux_gpio_driver = { 85 .driver = { 86 .name = "mdio-mux-gpio", 87 .of_match_table = mdio_mux_gpio_match, 88 }, 89 .probe = mdio_mux_gpio_probe, 90 .remove = mdio_mux_gpio_remove, 91 }; 92 93 module_platform_driver(mdio_mux_gpio_driver); 94 95 MODULE_DESCRIPTION(DRV_DESCRIPTION); 96 MODULE_VERSION(DRV_VERSION); 97 MODULE_AUTHOR("David Daney"); 98 MODULE_LICENSE("GPL v2"); 99