drivers/phy/phy-can-transceiver.c

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