1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * phy-can-transceiver.c - phy driver for CAN transceivers 4 * 5 * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com 6 * 7 */ 8 #include<linux/phy/phy.h> 9 #include<linux/platform_device.h> 10 #include<linux/module.h> 11 #include<linux/gpio.h> 12 #include<linux/gpio/consumer.h> 13 #include <linux/mux/consumer.h> 14 15 struct can_transceiver_data { 16 u32 flags; 17 #define CAN_TRANSCEIVER_STB_PRESENT BIT(0) 18 #define CAN_TRANSCEIVER_EN_PRESENT BIT(1) 19 }; 20 21 struct can_transceiver_phy { 22 struct phy *generic_phy; 23 struct gpio_desc *standby_gpio; 24 struct gpio_desc *enable_gpio; 25 struct mux_state *mux_state; 26 }; 27 28 /* Power on function */ 29 static int can_transceiver_phy_power_on(struct phy *phy) 30 { 31 struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy); 32 int ret; 33 34 if (can_transceiver_phy->mux_state) { 35 ret = mux_state_select(can_transceiver_phy->mux_state); 36 if (ret) { 37 dev_err(&phy->dev, "Failed to select CAN mux: %d\n", ret); 38 return ret; 39 } 40 } 41 if (can_transceiver_phy->standby_gpio) 42 gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 0); 43 if (can_transceiver_phy->enable_gpio) 44 gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 1); 45 46 return 0; 47 } 48 49 /* Power off function */ 50 static int can_transceiver_phy_power_off(struct phy *phy) 51 { 52 struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy); 53 54 if (can_transceiver_phy->standby_gpio) 55 gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 1); 56 if (can_transceiver_phy->enable_gpio) 57 gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 0); 58 if (can_transceiver_phy->mux_state) 59 mux_state_deselect(can_transceiver_phy->mux_state); 60 61 return 0; 62 } 63 64 static const struct phy_ops can_transceiver_phy_ops = { 65 .power_on = can_transceiver_phy_power_on, 66 .power_off = can_transceiver_phy_power_off, 67 .owner = THIS_MODULE, 68 }; 69 70 static const struct can_transceiver_data tcan1042_drvdata = { 71 .flags = CAN_TRANSCEIVER_STB_PRESENT, 72 }; 73 74 static const struct can_transceiver_data tcan1043_drvdata = { 75 .flags = CAN_TRANSCEIVER_STB_PRESENT | CAN_TRANSCEIVER_EN_PRESENT, 76 }; 77 78 static const struct of_device_id can_transceiver_phy_ids[] = { 79 { 80 .compatible = "ti,tcan1042", 81 .data = &tcan1042_drvdata 82 }, 83 { 84 .compatible = "ti,tcan1043", 85 .data = &tcan1043_drvdata 86 }, 87 { } 88 }; 89 MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids); 90 91 static int can_transceiver_phy_probe(struct platform_device *pdev) 92 { 93 struct phy_provider *phy_provider; 94 struct device *dev = &pdev->dev; 95 struct can_transceiver_phy *can_transceiver_phy; 96 const struct can_transceiver_data *drvdata; 97 const struct of_device_id *match; 98 struct phy *phy; 99 struct gpio_desc *standby_gpio; 100 struct gpio_desc *enable_gpio; 101 u32 max_bitrate = 0; 102 103 can_transceiver_phy = devm_kzalloc(dev, sizeof(struct can_transceiver_phy), GFP_KERNEL); 104 if (!can_transceiver_phy) 105 return -ENOMEM; 106 107 match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node); 108 drvdata = match->data; 109 110 if (of_property_read_bool(dev->of_node, "mux-states")) { 111 struct mux_state *mux_state; 112 113 mux_state = devm_mux_state_get(dev, NULL); 114 if (IS_ERR(mux_state)) 115 return dev_err_probe(&pdev->dev, PTR_ERR(mux_state), 116 "failed to get mux\n"); 117 can_transceiver_phy->mux_state = mux_state; 118 } 119 120 phy = devm_phy_create(dev, dev->of_node, 121 &can_transceiver_phy_ops); 122 if (IS_ERR(phy)) { 123 dev_err(dev, "failed to create can transceiver phy\n"); 124 return PTR_ERR(phy); 125 } 126 127 device_property_read_u32(dev, "max-bitrate", &max_bitrate); 128 if (!max_bitrate) 129 dev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit\n"); 130 phy->attrs.max_link_rate = max_bitrate; 131 132 can_transceiver_phy->generic_phy = phy; 133 134 if (drvdata->flags & CAN_TRANSCEIVER_STB_PRESENT) { 135 standby_gpio = devm_gpiod_get_optional(dev, "standby", GPIOD_OUT_HIGH); 136 if (IS_ERR(standby_gpio)) 137 return PTR_ERR(standby_gpio); 138 can_transceiver_phy->standby_gpio = standby_gpio; 139 } 140 141 if (drvdata->flags & CAN_TRANSCEIVER_EN_PRESENT) { 142 enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW); 143 if (IS_ERR(enable_gpio)) 144 return PTR_ERR(enable_gpio); 145 can_transceiver_phy->enable_gpio = enable_gpio; 146 } 147 148 phy_set_drvdata(can_transceiver_phy->generic_phy, can_transceiver_phy); 149 150 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); 151 152 return PTR_ERR_OR_ZERO(phy_provider); 153 } 154 155 static struct platform_driver can_transceiver_phy_driver = { 156 .probe = can_transceiver_phy_probe, 157 .driver = { 158 .name = "can-transceiver-phy", 159 .of_match_table = can_transceiver_phy_ids, 160 }, 161 }; 162 163 module_platform_driver(can_transceiver_phy_driver); 164 165 MODULE_AUTHOR("Faiz Abbas <faiz_abbas@ti.com>"); 166 MODULE_AUTHOR("Aswath Govindraju <a-govindraju@ti.com>"); 167 MODULE_DESCRIPTION("CAN TRANSCEIVER PHY driver"); 168 MODULE_LICENSE("GPL v2"); 169