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/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#define CAN_TRANSCEIVER_DUAL_CH		BIT(2)
 21#define CAN_TRANSCEIVER_SILENT_PRESENT	BIT(3)
 22};
 23
 24struct can_transceiver_phy {
 25	struct phy *generic_phy;
 26	struct gpio_desc *silent_gpio;
 27	struct gpio_desc *standby_gpio;
 28	struct gpio_desc *enable_gpio;
 29	struct can_transceiver_priv *priv;
 30};
 31
 32struct can_transceiver_priv {
 33	struct mux_state *mux_state;
 34	int num_ch;
 35	struct can_transceiver_phy can_transceiver_phy[] __counted_by(num_ch);
 36};
 37
 38/* Power on function */
 39static int can_transceiver_phy_power_on(struct phy *phy)
 40{
 41	struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy);
 42	struct can_transceiver_priv *priv = can_transceiver_phy->priv;
 43	int ret;
 44
 45	if (priv->mux_state) {
 46		ret = mux_state_select(priv->mux_state);
 47		if (ret) {
 48			dev_err(&phy->dev, "Failed to select CAN mux: %d\n", ret);
 49			return ret;
 50		}
 51	}
 52	gpiod_set_value_cansleep(can_transceiver_phy->silent_gpio, 0);
 53	gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 0);
 54	gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 1);
 55
 56	return 0;
 57}
 58
 59/* Power off function */
 60static int can_transceiver_phy_power_off(struct phy *phy)
 61{
 62	struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy);
 63	struct can_transceiver_priv *priv = can_transceiver_phy->priv;
 64
 65	gpiod_set_value_cansleep(can_transceiver_phy->silent_gpio, 1);
 66	gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 1);
 67	gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 0);
 68	if (priv->mux_state)
 69		mux_state_deselect(priv->mux_state);
 70
 71	return 0;
 72}
 73
 74static const struct phy_ops can_transceiver_phy_ops = {
 75	.power_on	= can_transceiver_phy_power_on,
 76	.power_off	= can_transceiver_phy_power_off,
 77	.owner		= THIS_MODULE,
 78};
 79
 80static const struct can_transceiver_data tcan1042_drvdata = {
 81	.flags = CAN_TRANSCEIVER_STB_PRESENT,
 82};
 83
 84static const struct can_transceiver_data tcan1043_drvdata = {
 85	.flags = CAN_TRANSCEIVER_STB_PRESENT | CAN_TRANSCEIVER_EN_PRESENT,
 86};
 87
 88static const struct can_transceiver_data tja1048_drvdata = {
 89	.flags = CAN_TRANSCEIVER_STB_PRESENT | CAN_TRANSCEIVER_DUAL_CH,
 90};
 91
 92static const struct can_transceiver_data tja1051_drvdata = {
 93	.flags = CAN_TRANSCEIVER_SILENT_PRESENT | CAN_TRANSCEIVER_EN_PRESENT,
 94};
 95
 96static const struct can_transceiver_data tja1057_drvdata = {
 97	.flags = CAN_TRANSCEIVER_SILENT_PRESENT,
 98};
 99
100static const struct of_device_id can_transceiver_phy_ids[] = {
101	{
102		.compatible = "ti,tcan1042",
103		.data = &tcan1042_drvdata
104	},
105	{
106		.compatible = "ti,tcan1043",
107		.data = &tcan1043_drvdata
108	},
109	{
110		.compatible = "nxp,tja1048",
111		.data = &tja1048_drvdata
112	},
113	{
114		.compatible = "nxp,tja1051",
115		.data = &tja1051_drvdata
116	},
117	{
118		.compatible = "nxp,tja1057",
119		.data = &tja1057_drvdata
120	},
121	{
122		.compatible = "nxp,tjr1443",
123		.data = &tcan1043_drvdata
124	},
125	{ }
126};
127MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids);
128
129/* Temporary wrapper until the multiplexer subsystem supports optional muxes */
130static inline struct mux_state *
131devm_mux_state_get_optional(struct device *dev, const char *mux_name)
132{
133	if (!of_property_present(dev->of_node, "mux-states"))
134		return NULL;
135
136	return devm_mux_state_get(dev, mux_name);
137}
138
139static struct phy *can_transceiver_phy_xlate(struct device *dev,
140					     const struct of_phandle_args *args)
141{
142	struct can_transceiver_priv *priv = dev_get_drvdata(dev);
143	u32 idx;
144
145	if (priv->num_ch == 1)
146		return priv->can_transceiver_phy[0].generic_phy;
147
148	if (args->args_count != 1)
149		return ERR_PTR(-EINVAL);
150
151	idx = args->args[0];
152	if (idx >= priv->num_ch)
153		return ERR_PTR(-EINVAL);
154
155	return priv->can_transceiver_phy[idx].generic_phy;
156}
157
158static int can_transceiver_phy_probe(struct platform_device *pdev)
159{
160	struct phy_provider *phy_provider;
161	struct device *dev = &pdev->dev;
162	struct can_transceiver_phy *can_transceiver_phy;
163	struct can_transceiver_priv *priv;
164	const struct can_transceiver_data *drvdata;
165	const struct of_device_id *match;
166	struct phy *phy;
167	struct gpio_desc *silent_gpio;
168	struct gpio_desc *standby_gpio;
169	struct gpio_desc *enable_gpio;
170	struct mux_state *mux_state;
171	u32 max_bitrate = 0;
172	int err, i, num_ch = 1;
173
174	match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node);
175	drvdata = match->data;
176	if (drvdata->flags & CAN_TRANSCEIVER_DUAL_CH)
177		num_ch = 2;
178
179	priv = devm_kzalloc(dev, struct_size(priv, can_transceiver_phy, num_ch), GFP_KERNEL);
180	if (!priv)
181		return -ENOMEM;
182
183	priv->num_ch = num_ch;
184	platform_set_drvdata(pdev, priv);
185
186	mux_state = devm_mux_state_get_optional(dev, NULL);
187	if (IS_ERR(mux_state))
188		return PTR_ERR(mux_state);
189
190	priv->mux_state = mux_state;
191
192	err = device_property_read_u32(dev, "max-bitrate", &max_bitrate);
193	if ((err != -EINVAL) && !max_bitrate)
194		dev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit\n");
195
196	for (i = 0; i < num_ch; i++) {
197		can_transceiver_phy = &priv->can_transceiver_phy[i];
198		can_transceiver_phy->priv = priv;
199
200		phy = devm_phy_create(dev, dev->of_node, &can_transceiver_phy_ops);
201		if (IS_ERR(phy)) {
202			dev_err(dev, "failed to create can transceiver phy\n");
203			return PTR_ERR(phy);
204		}
205
206		phy->attrs.max_link_rate = max_bitrate;
207
208		can_transceiver_phy->generic_phy = phy;
209		can_transceiver_phy->priv = priv;
210
211		if (drvdata->flags & CAN_TRANSCEIVER_STB_PRESENT) {
212			standby_gpio = devm_gpiod_get_index_optional(dev, "standby", i,
213								     GPIOD_OUT_HIGH);
214			if (IS_ERR(standby_gpio))
215				return PTR_ERR(standby_gpio);
216			can_transceiver_phy->standby_gpio = standby_gpio;
217		}
218
219		if (drvdata->flags & CAN_TRANSCEIVER_EN_PRESENT) {
220			enable_gpio = devm_gpiod_get_index_optional(dev, "enable", i,
221								    GPIOD_OUT_LOW);
222			if (IS_ERR(enable_gpio))
223				return PTR_ERR(enable_gpio);
224			can_transceiver_phy->enable_gpio = enable_gpio;
225		}
226
227		if (drvdata->flags & CAN_TRANSCEIVER_SILENT_PRESENT) {
228			silent_gpio = devm_gpiod_get_index_optional(dev, "silent", i,
229								    GPIOD_OUT_LOW);
230			if (IS_ERR(silent_gpio))
231				return PTR_ERR(silent_gpio);
232			can_transceiver_phy->silent_gpio = silent_gpio;
233		}
234
235		phy_set_drvdata(can_transceiver_phy->generic_phy, can_transceiver_phy);
236
237	}
238
239	phy_provider = devm_of_phy_provider_register(dev, can_transceiver_phy_xlate);
240
241	return PTR_ERR_OR_ZERO(phy_provider);
242}
243
244static struct platform_driver can_transceiver_phy_driver = {
245	.probe = can_transceiver_phy_probe,
246	.driver = {
247		.name = "can-transceiver-phy",
248		.of_match_table = can_transceiver_phy_ids,
249	},
250};
251
252module_platform_driver(can_transceiver_phy_driver);
253
254MODULE_AUTHOR("Faiz Abbas <faiz_abbas@ti.com>");
255MODULE_AUTHOR("Aswath Govindraju <a-govindraju@ti.com>");
256MODULE_DESCRIPTION("CAN TRANSCEIVER PHY driver");
257MODULE_LICENSE("GPL v2");