tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
16struct can_transceiver_data {
17 u32 flags;
18#define CAN_TRANSCEIVER_STB_PRESENT BIT(0)
19#define CAN_TRANSCEIVER_EN_PRESENT BIT(1)
20};
21
22struct 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 */
30static 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 */
51static 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
65static 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
71static const struct can_transceiver_data tcan1042_drvdata = {
72 .flags = CAN_TRANSCEIVER_STB_PRESENT,
73};
74
75static const struct can_transceiver_data tcan1043_drvdata = {
76 .flags = CAN_TRANSCEIVER_STB_PRESENT | CAN_TRANSCEIVER_EN_PRESENT,
77};
78
79static 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};
94MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids);
95
96/* Temporary wrapper until the multiplexer subsystem supports optional muxes */
97static inline struct mux_state *
98devm_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
106static 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
168static 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
176module_platform_driver(can_transceiver_phy_driver);
177
178MODULE_AUTHOR("Faiz Abbas <faiz_abbas@ti.com>");
179MODULE_AUTHOR("Aswath Govindraju <a-govindraju@ti.com>");
180MODULE_DESCRIPTION("CAN TRANSCEIVER PHY driver");
181MODULE_LICENSE("GPL v2");