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 /* Temporary wrapper until the multiplexer subsystem supports optional muxes */ 97 static inline struct mux_state * 98 devm_mux_state_get_optional(struct device *dev, const char *mux_name) 99 { 100 if (!of_property_present(dev->of_node, "mux-states")) 101 return NULL; 102 103 return devm_mux_state_get(dev, mux_name); 104 } 105 106 static int can_transceiver_phy_probe(struct platform_device *pdev) 107 { 108 struct phy_provider *phy_provider; 109 struct device *dev = &pdev->dev; 110 struct can_transceiver_phy *can_transceiver_phy; 111 const struct can_transceiver_data *drvdata; 112 const struct of_device_id *match; 113 struct phy *phy; 114 struct gpio_desc *standby_gpio; 115 struct gpio_desc *enable_gpio; 116 struct mux_state *mux_state; 117 u32 max_bitrate = 0; 118 int err; 119 120 can_transceiver_phy = devm_kzalloc(dev, sizeof(struct can_transceiver_phy), GFP_KERNEL); 121 if (!can_transceiver_phy) 122 return -ENOMEM; 123 124 match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node); 125 drvdata = match->data; 126 127 mux_state = devm_mux_state_get_optional(dev, NULL); 128 if (IS_ERR(mux_state)) 129 return PTR_ERR(mux_state); 130 131 can_transceiver_phy->mux_state = mux_state; 132 133 phy = devm_phy_create(dev, dev->of_node, 134 &can_transceiver_phy_ops); 135 if (IS_ERR(phy)) { 136 dev_err(dev, "failed to create can transceiver phy\n"); 137 return PTR_ERR(phy); 138 } 139 140 err = device_property_read_u32(dev, "max-bitrate", &max_bitrate); 141 if ((err != -EINVAL) && !max_bitrate) 142 dev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit\n"); 143 phy->attrs.max_link_rate = max_bitrate; 144 145 can_transceiver_phy->generic_phy = phy; 146 147 if (drvdata->flags & CAN_TRANSCEIVER_STB_PRESENT) { 148 standby_gpio = devm_gpiod_get_optional(dev, "standby", GPIOD_OUT_HIGH); 149 if (IS_ERR(standby_gpio)) 150 return PTR_ERR(standby_gpio); 151 can_transceiver_phy->standby_gpio = standby_gpio; 152 } 153 154 if (drvdata->flags & CAN_TRANSCEIVER_EN_PRESENT) { 155 enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW); 156 if (IS_ERR(enable_gpio)) 157 return PTR_ERR(enable_gpio); 158 can_transceiver_phy->enable_gpio = enable_gpio; 159 } 160 161 phy_set_drvdata(can_transceiver_phy->generic_phy, can_transceiver_phy); 162 163 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); 164 165 return PTR_ERR_OR_ZERO(phy_provider); 166 } 167 168 static struct platform_driver can_transceiver_phy_driver = { 169 .probe = can_transceiver_phy_probe, 170 .driver = { 171 .name = "can-transceiver-phy", 172 .of_match_table = can_transceiver_phy_ids, 173 }, 174 }; 175 176 module_platform_driver(can_transceiver_phy_driver); 177 178 MODULE_AUTHOR("Faiz Abbas <faiz_abbas@ti.com>"); 179 MODULE_AUTHOR("Aswath Govindraju <a-govindraju@ti.com>"); 180 MODULE_DESCRIPTION("CAN TRANSCEIVER PHY driver"); 181 MODULE_LICENSE("GPL v2"); 182