1 // SPDX-License-Identifier: GPL-2.0-only
3  * Pinctrl based I2C DeMultiplexer
5  * Copyright (C) 2015-16 by Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
6  * Copyright (C) 2015-16 by Renesas Electronics Corporation
9  * (look for filenames containing 'i2c-demux-pinctrl' in Documentation/)
12 #include <linux/i2c.h>
16 #include <linux/pinctrl/consumer.h>
40 	struct i2c_demux_pinctrl_priv *priv = adap->algo_data;  in i2c_demux_master_xfer()
41 	struct i2c_adapter *parent = priv->chan[priv->cur_chan].parent_adap;  in i2c_demux_master_xfer()
48 	struct i2c_demux_pinctrl_priv *priv = adap->algo_data;  in i2c_demux_functionality()
49 	struct i2c_adapter *parent = priv->chan[priv->cur_chan].parent_adap;  in i2c_demux_functionality()
51 	return parent->algo->functionality(parent);  in i2c_demux_functionality()
57 	struct pinctrl *p;  in i2c_demux_activate_master()
60 	ret = of_changeset_apply(&priv->chan[new_chan].chgset);  in i2c_demux_activate_master()
64 	adap = of_get_i2c_adapter_by_node(priv->chan[new_chan].parent_np);  in i2c_demux_activate_master()
66 		ret = -ENODEV;  in i2c_demux_activate_master()
71 	 * Check if there are pinctrl states at all. Note: we can't use  in i2c_demux_activate_master()
73 	 * the -ENODEV from devm_pinctrl_get() and pinctrl_lookup_state().  in i2c_demux_activate_master()
75 	p = devm_pinctrl_get(adap->dev.parent);  in i2c_demux_activate_master()
78 		/* continue if just no pinctrl states (e.g. i2c-gpio), otherwise exit */  in i2c_demux_activate_master()
79 		if (ret != -ENODEV)  in i2c_demux_activate_master()
83 		struct pinctrl_state *s = pinctrl_lookup_state(p, priv->bus_name);  in i2c_demux_activate_master()
94 	priv->chan[new_chan].parent_adap = adap;  in i2c_demux_activate_master()
95 	priv->cur_chan = new_chan;  in i2c_demux_activate_master()
98 	priv->algo.master_xfer = i2c_demux_master_xfer;  in i2c_demux_activate_master()
99 	if (adap->algo->master_xfer_atomic)  in i2c_demux_activate_master()
100 		priv->algo.master_xfer_atomic = i2c_demux_master_xfer;  in i2c_demux_activate_master()
101 	priv->algo.functionality = i2c_demux_functionality;  in i2c_demux_activate_master()
103 	snprintf(priv->cur_adap.name, sizeof(priv->cur_adap.name),  in i2c_demux_activate_master()
104 		 "i2c-demux (master i2c-%d)", i2c_adapter_id(adap));  in i2c_demux_activate_master()
105 	priv->cur_adap.owner = THIS_MODULE;  in i2c_demux_activate_master()
106 	priv->cur_adap.algo = &priv->algo;  in i2c_demux_activate_master()
107 	priv->cur_adap.algo_data = priv;  in i2c_demux_activate_master()
108 	priv->cur_adap.dev.parent = &adap->dev;  in i2c_demux_activate_master()
109 	priv->cur_adap.class = adap->class;  in i2c_demux_activate_master()
110 	priv->cur_adap.retries = adap->retries;  in i2c_demux_activate_master()
111 	priv->cur_adap.timeout = adap->timeout;  in i2c_demux_activate_master()
112 	priv->cur_adap.quirks = adap->quirks;  in i2c_demux_activate_master()
113 	priv->cur_adap.dev.of_node = priv->dev->of_node;  in i2c_demux_activate_master()
114 	ret = i2c_add_adapter(&priv->cur_adap);  in i2c_demux_activate_master()
123 	of_changeset_revert(&priv->chan[new_chan].chgset);  in i2c_demux_activate_master()
125 	dev_err(priv->dev, "failed to setup demux-adapter %d (%d)\n", new_chan, ret);  in i2c_demux_activate_master()
126 	priv->cur_chan = -EINVAL;  in i2c_demux_activate_master()
132 	int ret, cur = priv->cur_chan;  in i2c_demux_deactivate_master()
137 	i2c_del_adapter(&priv->cur_adap);  in i2c_demux_deactivate_master()
138 	i2c_put_adapter(priv->chan[cur].parent_adap);  in i2c_demux_deactivate_master()
140 	ret = of_changeset_revert(&priv->chan[cur].chgset);  in i2c_demux_deactivate_master()
142 	priv->chan[cur].parent_adap = NULL;  in i2c_demux_deactivate_master()
143 	priv->cur_chan = -EINVAL;  in i2c_demux_deactivate_master()
152 	if (new_chan == priv->cur_chan)  in i2c_demux_change_master()
169 	for (i = 0; i < priv->num_chan && count < PAGE_SIZE; i++)  in available_masters_show()
171 				       i, priv->chan[i].parent_np,  in available_masters_show()
172 				       i == priv->num_chan - 1 ? '\n' : ' ');  in available_masters_show()
184 	return sprintf(buf, "%d\n", priv->cur_chan);  in current_master_show()
199 	if (val >= priv->num_chan)  in current_master_store()
200 		return -EINVAL;  in current_master_store()
210 	struct device_node *np = pdev->dev.of_node;  in i2c_demux_pinctrl_probe()
215 	num_chan = of_count_phandle_with_args(np, "i2c-parent", NULL);  in i2c_demux_pinctrl_probe()
217 		dev_err(&pdev->dev, "Need at least two I2C masters to switch\n");  in i2c_demux_pinctrl_probe()
218 		return -EINVAL;  in i2c_demux_pinctrl_probe()
221 	priv = devm_kzalloc(&pdev->dev, struct_size(priv, chan, num_chan),  in i2c_demux_pinctrl_probe()
224 	props = devm_kcalloc(&pdev->dev, num_chan, sizeof(*props), GFP_KERNEL);  in i2c_demux_pinctrl_probe()
227 		return -ENOMEM;  in i2c_demux_pinctrl_probe()
229 	priv->num_chan = num_chan;  in i2c_demux_pinctrl_probe()
231 	err = of_property_read_string(np, "i2c-bus-name", &priv->bus_name);  in i2c_demux_pinctrl_probe()
238 		adap_np = of_parse_phandle(np, "i2c-parent", i);  in i2c_demux_pinctrl_probe()
240 			dev_err(&pdev->dev, "can't get phandle for parent %d\n", i);  in i2c_demux_pinctrl_probe()
241 			err = -ENOENT;  in i2c_demux_pinctrl_probe()
244 		priv->chan[i].parent_np = adap_np;  in i2c_demux_pinctrl_probe()
246 		props[i].name = devm_kstrdup(&pdev->dev, "status", GFP_KERNEL);  in i2c_demux_pinctrl_probe()
247 		props[i].value = devm_kstrdup(&pdev->dev, "ok", GFP_KERNEL);  in i2c_demux_pinctrl_probe()
249 			err = -ENOMEM;  in i2c_demux_pinctrl_probe()
254 		of_changeset_init(&priv->chan[i].chgset);  in i2c_demux_pinctrl_probe()
255 		of_changeset_update_property(&priv->chan[i].chgset, adap_np, &props[i]);  in i2c_demux_pinctrl_probe()
258 	priv->dev = &pdev->dev;  in i2c_demux_pinctrl_probe()
261 	pm_runtime_no_callbacks(&pdev->dev);  in i2c_demux_pinctrl_probe()
268 	err = device_create_file(&pdev->dev, &dev_attr_available_masters);  in i2c_demux_pinctrl_probe()
272 	err = device_create_file(&pdev->dev, &dev_attr_current_master);  in i2c_demux_pinctrl_probe()
279 	device_remove_file(&pdev->dev, &dev_attr_available_masters);  in i2c_demux_pinctrl_probe()
284 		of_node_put(priv->chan[j].parent_np);  in i2c_demux_pinctrl_probe()
285 		of_changeset_destroy(&priv->chan[j].chgset);  in i2c_demux_pinctrl_probe()
296 	device_remove_file(&pdev->dev, &dev_attr_current_master);  in i2c_demux_pinctrl_remove()
297 	device_remove_file(&pdev->dev, &dev_attr_available_masters);  in i2c_demux_pinctrl_remove()
301 	for (i = 0; i < priv->num_chan; i++) {  in i2c_demux_pinctrl_remove()
302 		of_node_put(priv->chan[i].parent_np);  in i2c_demux_pinctrl_remove()
303 		of_changeset_destroy(&priv->chan[i].chgset);  in i2c_demux_pinctrl_remove()
308 	{ .compatible = "i2c-demux-pinctrl", },
315 		.name = "i2c-demux-pinctrl",
323 MODULE_DESCRIPTION("pinctrl-based I2C demux driver");
324 MODULE_AUTHOR("Wolfram Sang <wsa@sang-engineering.com>");
326 MODULE_ALIAS("platform:i2c-demux-pinctrl");