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 .compatible = "nxp,tjr1443", 89 .data = &tcan1043_drvdata 90 }, 91 { } 92 }; 93 MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids); 94 95 static int can_transceiver_phy_probe(struct platform_device *pdev) 96 { 97 struct phy_provider *phy_provider; 98 struct device *dev = &pdev->dev; 99 struct can_transceiver_phy *can_transceiver_phy; 100 const struct can_transceiver_data *drvdata; 101 const struct of_device_id *match; 102 struct phy *phy; 103 struct gpio_desc *standby_gpio; 104 struct gpio_desc *enable_gpio; 105 u32 max_bitrate = 0; 106 int err; 107 108 can_transceiver_phy = devm_kzalloc(dev, sizeof(struct can_transceiver_phy), GFP_KERNEL); 109 if (!can_transceiver_phy) 110 return -ENOMEM; 111 112 match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node); 113 drvdata = match->data; 114 115 if (of_property_read_bool(dev->of_node, "mux-states")) { 116 struct mux_state *mux_state; 117 118 mux_state = devm_mux_state_get(dev, NULL); 119 if (IS_ERR(mux_state)) 120 return dev_err_probe(&pdev->dev, PTR_ERR(mux_state), 121 "failed to get mux\n"); 122 can_transceiver_phy->mux_state = mux_state; 123 } 124 125 phy = devm_phy_create(dev, dev->of_node, 126 &can_transceiver_phy_ops); 127 if (IS_ERR(phy)) { 128 dev_err(dev, "failed to create can transceiver phy\n"); 129 return PTR_ERR(phy); 130 } 131 132 err = device_property_read_u32(dev, "max-bitrate", &max_bitrate); 133 if ((err != -EINVAL) && !max_bitrate) 134 dev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit\n"); 135 phy->attrs.max_link_rate = max_bitrate; 136 137 can_transceiver_phy->generic_phy = phy; 138 139 if (drvdata->flags & CAN_TRANSCEIVER_STB_PRESENT) { 140 standby_gpio = devm_gpiod_get_optional(dev, "standby", GPIOD_OUT_HIGH); 141 if (IS_ERR(standby_gpio)) 142 return PTR_ERR(standby_gpio); 143 can_transceiver_phy->standby_gpio = standby_gpio; 144 } 145 146 if (drvdata->flags & CAN_TRANSCEIVER_EN_PRESENT) { 147 enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW); 148 if (IS_ERR(enable_gpio)) 149 return PTR_ERR(enable_gpio); 150 can_transceiver_phy->enable_gpio = enable_gpio; 151 } 152 153 phy_set_drvdata(can_transceiver_phy->generic_phy, can_transceiver_phy); 154 155 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); 156 157 return PTR_ERR_OR_ZERO(phy_provider); 158 } 159 160 static struct platform_driver can_transceiver_phy_driver = { 161 .probe = can_transceiver_phy_probe, 162 .driver = { 163 .name = "can-transceiver-phy", 164 .of_match_table = can_transceiver_phy_ids, 165 }, 166 }; 167 168 module_platform_driver(can_transceiver_phy_driver); 169 170 MODULE_AUTHOR("Faiz Abbas <faiz_abbas@ti.com>"); 171 MODULE_AUTHOR("Aswath Govindraju <a-govindraju@ti.com>"); 172 MODULE_DESCRIPTION("CAN TRANSCEIVER PHY driver"); 173 MODULE_LICENSE("GPL v2"); 174