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/of.h> 9 #include <linux/phy/phy.h> 10 #include <linux/platform_device.h> 11 #include <linux/module.h> 12 #include <linux/gpio.h> 13 #include <linux/gpio/consumer.h> 14 #include <linux/mux/consumer.h> 15 16 struct can_transceiver_data { 17 u32 flags; 18 #define CAN_TRANSCEIVER_STB_PRESENT BIT(0) 19 #define CAN_TRANSCEIVER_EN_PRESENT BIT(1) 20 }; 21 22 struct can_transceiver_phy { 23 struct phy *generic_phy; 24 struct gpio_desc *standby_gpio; 25 struct gpio_desc *enable_gpio; 26 struct mux_state *mux_state; 27 }; 28 29 /* Power on function */ 30 static int can_transceiver_phy_power_on(struct phy *phy) 31 { 32 struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy); 33 int ret; 34 35 if (can_transceiver_phy->mux_state) { 36 ret = mux_state_select(can_transceiver_phy->mux_state); 37 if (ret) { 38 dev_err(&phy->dev, "Failed to select CAN mux: %d\n", ret); 39 return ret; 40 } 41 } 42 if (can_transceiver_phy->standby_gpio) 43 gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 0); 44 if (can_transceiver_phy->enable_gpio) 45 gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 1); 46 47 return 0; 48 } 49 50 /* Power off function */ 51 static int can_transceiver_phy_power_off(struct phy *phy) 52 { 53 struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy); 54 55 if (can_transceiver_phy->standby_gpio) 56 gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 1); 57 if (can_transceiver_phy->enable_gpio) 58 gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 0); 59 if (can_transceiver_phy->mux_state) 60 mux_state_deselect(can_transceiver_phy->mux_state); 61 62 return 0; 63 } 64 65 static const struct phy_ops can_transceiver_phy_ops = { 66 .power_on = can_transceiver_phy_power_on, 67 .power_off = can_transceiver_phy_power_off, 68 .owner = THIS_MODULE, 69 }; 70 71 static const struct can_transceiver_data tcan1042_drvdata = { 72 .flags = CAN_TRANSCEIVER_STB_PRESENT, 73 }; 74 75 static const struct can_transceiver_data tcan1043_drvdata = { 76 .flags = CAN_TRANSCEIVER_STB_PRESENT | CAN_TRANSCEIVER_EN_PRESENT, 77 }; 78 79 static const struct of_device_id can_transceiver_phy_ids[] = { 80 { 81 .compatible = "ti,tcan1042", 82 .data = &tcan1042_drvdata 83 }, 84 { 85 .compatible = "ti,tcan1043", 86 .data = &tcan1043_drvdata 87 }, 88 { 89 .compatible = "nxp,tjr1443", 90 .data = &tcan1043_drvdata 91 }, 92 { } 93 }; 94 MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids); 95 96 static int can_transceiver_phy_probe(struct platform_device *pdev) 97 { 98 struct phy_provider *phy_provider; 99 struct device *dev = &pdev->dev; 100 struct can_transceiver_phy *can_transceiver_phy; 101 const struct can_transceiver_data *drvdata; 102 const struct of_device_id *match; 103 struct phy *phy; 104 struct gpio_desc *standby_gpio; 105 struct gpio_desc *enable_gpio; 106 u32 max_bitrate = 0; 107 int err; 108 109 can_transceiver_phy = devm_kzalloc(dev, sizeof(struct can_transceiver_phy), GFP_KERNEL); 110 if (!can_transceiver_phy) 111 return -ENOMEM; 112 113 match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node); 114 drvdata = match->data; 115 116 if (of_property_read_bool(dev->of_node, "mux-states")) { 117 struct mux_state *mux_state; 118 119 mux_state = devm_mux_state_get(dev, NULL); 120 if (IS_ERR(mux_state)) 121 return dev_err_probe(&pdev->dev, PTR_ERR(mux_state), 122 "failed to get mux\n"); 123 can_transceiver_phy->mux_state = mux_state; 124 } 125 126 phy = devm_phy_create(dev, dev->of_node, 127 &can_transceiver_phy_ops); 128 if (IS_ERR(phy)) { 129 dev_err(dev, "failed to create can transceiver phy\n"); 130 return PTR_ERR(phy); 131 } 132 133 err = device_property_read_u32(dev, "max-bitrate", &max_bitrate); 134 if ((err != -EINVAL) && !max_bitrate) 135 dev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit\n"); 136 phy->attrs.max_link_rate = max_bitrate; 137 138 can_transceiver_phy->generic_phy = phy; 139 140 if (drvdata->flags & CAN_TRANSCEIVER_STB_PRESENT) { 141 standby_gpio = devm_gpiod_get_optional(dev, "standby", GPIOD_OUT_HIGH); 142 if (IS_ERR(standby_gpio)) 143 return PTR_ERR(standby_gpio); 144 can_transceiver_phy->standby_gpio = standby_gpio; 145 } 146 147 if (drvdata->flags & CAN_TRANSCEIVER_EN_PRESENT) { 148 enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW); 149 if (IS_ERR(enable_gpio)) 150 return PTR_ERR(enable_gpio); 151 can_transceiver_phy->enable_gpio = enable_gpio; 152 } 153 154 phy_set_drvdata(can_transceiver_phy->generic_phy, can_transceiver_phy); 155 156 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); 157 158 return PTR_ERR_OR_ZERO(phy_provider); 159 } 160 161 static struct platform_driver can_transceiver_phy_driver = { 162 .probe = can_transceiver_phy_probe, 163 .driver = { 164 .name = "can-transceiver-phy", 165 .of_match_table = can_transceiver_phy_ids, 166 }, 167 }; 168 169 module_platform_driver(can_transceiver_phy_driver); 170 171 MODULE_AUTHOR("Faiz Abbas <faiz_abbas@ti.com>"); 172 MODULE_AUTHOR("Aswath Govindraju <a-govindraju@ti.com>"); 173 MODULE_DESCRIPTION("CAN TRANSCEIVER PHY driver"); 174 MODULE_LICENSE("GPL v2"); 175