1/*
  2 * Intel Cherry Trail ACPI INT33FE pseudo device driver
  3 *
  4 * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 *
 10 * Some Intel Cherry Trail based device which ship with Windows 10, have
 11 * this weird INT33FE ACPI device with a CRS table with 4 I2cSerialBusV2
 12 * resources, for 4 different chips attached to various i2c busses:
 13 * 1. The Whiskey Cove pmic, which is also described by the INT34D3 ACPI device
 14 * 2. Maxim MAX17047 Fuel Gauge Controller
 15 * 3. FUSB302 USB Type-C Controller
 16 * 4. PI3USB30532 USB switch
 17 *
 18 * So this driver is a stub / pseudo driver whose only purpose is to
 19 * instantiate i2c-clients for chips 2 - 4, so that standard i2c drivers
 20 * for these chips can bind to the them.
 21 */
 22
 23#include <linux/acpi.h>
 24#include <linux/i2c.h>
 25#include <linux/interrupt.h>
 26#include <linux/module.h>
 27#include <linux/regulator/consumer.h>
 28#include <linux/slab.h>
 29
 30#define EXPECTED_PTYPE		4
 31
 32struct cht_int33fe_data {
 33	struct i2c_client *max17047;
 34	struct i2c_client *fusb302;
 35	struct i2c_client *pi3usb30532;
 36	/* Contain a list-head must be per device */
 37	struct device_connection connections[3];
 38};
 39
 40/*
 41 * Grrr I severly dislike buggy BIOS-es. At least one BIOS enumerates
 42 * the max17047 both through the INT33FE ACPI device (it is right there
 43 * in the resources table) as well as through a separate MAX17047 device.
 44 *
 45 * These helpers are used to work around this by checking if an i2c-client
 46 * for the max17047 has already been registered.
 47 */
 48static int cht_int33fe_check_for_max17047(struct device *dev, void *data)
 49{
 50	struct i2c_client **max17047 = data;
 51	struct acpi_device *adev;
 52	const char *hid;
 53
 54	adev = ACPI_COMPANION(dev);
 55	if (!adev)
 56		return 0;
 57
 58	hid = acpi_device_hid(adev);
 59
 60	/* The MAX17047 ACPI node doesn't have an UID, so we don't check that */
 61	if (strcmp(hid, "MAX17047"))
 62		return 0;
 63
 64	*max17047 = to_i2c_client(dev);
 65	return 1;
 66}
 67
 68static struct i2c_client *cht_int33fe_find_max17047(void)
 69{
 70	struct i2c_client *max17047 = NULL;
 71
 72	i2c_for_each_dev(&max17047, cht_int33fe_check_for_max17047);
 73	return max17047;
 74}
 75
 76static const char * const max17047_suppliers[] = { "bq24190-charger" };
 77
 78static const struct property_entry max17047_props[] = {
 79	PROPERTY_ENTRY_STRING_ARRAY("supplied-from", max17047_suppliers),
 80	{ }
 81};
 82
 83static const struct property_entry fusb302_props[] = {
 84	PROPERTY_ENTRY_STRING("fcs,extcon-name", "cht_wcove_pwrsrc"),
 85	PROPERTY_ENTRY_U32("fcs,max-sink-microvolt", 12000000),
 86	PROPERTY_ENTRY_U32("fcs,max-sink-microamp",   3000000),
 87	PROPERTY_ENTRY_U32("fcs,max-sink-microwatt", 36000000),
 88	{ }
 89};
 90
 91static int cht_int33fe_probe(struct i2c_client *client)
 92{
 93	struct device *dev = &client->dev;
 94	struct i2c_board_info board_info;
 95	struct cht_int33fe_data *data;
 96	struct i2c_client *max17047;
 97	struct regulator *regulator;
 98	unsigned long long ptyp;
 99	acpi_status status;
100	int fusb302_irq;
101	int ret;
102
103	status = acpi_evaluate_integer(ACPI_HANDLE(dev), "PTYP", NULL, &ptyp);
104	if (ACPI_FAILURE(status)) {
105		dev_err(dev, "Error getting PTYPE\n");
106		return -ENODEV;
107	}
108
109	/*
110	 * The same ACPI HID is used for different configurations check PTYP
111	 * to ensure that we are dealing with the expected config.
112	 */
113	if (ptyp != EXPECTED_PTYPE)
114		return -ENODEV;
115
116	/* Check presence of INT34D3 (hardware-rev 3) expected for ptype == 4 */
117	if (!acpi_dev_present("INT34D3", "1", 3)) {
118		dev_err(dev, "Error PTYPE == %d, but no INT34D3 device\n",
119			EXPECTED_PTYPE);
120		return -ENODEV;
121	}
122
123	/*
124	 * We expect the WC PMIC to be paired with a TI bq24292i charger-IC.
125	 * We check for the bq24292i vbus regulator here, this has 2 purposes:
126	 * 1) The bq24292i allows charging with up to 12V, setting the fusb302's
127	 *    max-snk voltage to 12V with another charger-IC is not good.
128	 * 2) For the fusb302 driver to get the bq24292i vbus regulator, the
129	 *    regulator-map, which is part of the bq24292i regulator_init_data,
130	 *    must be registered before the fusb302 is instantiated, otherwise
131	 *    it will end up with a dummy-regulator.
132	 * Note "cht_wc_usb_typec_vbus" comes from the regulator_init_data
133	 * which is defined in i2c-cht-wc.c from where the bq24292i i2c-client
134	 * gets instantiated. We use regulator_get_optional here so that we
135	 * don't end up getting a dummy-regulator ourselves.
136	 */
137	regulator = regulator_get_optional(dev, "cht_wc_usb_typec_vbus");
138	if (IS_ERR(regulator)) {
139		ret = PTR_ERR(regulator);
140		return (ret == -ENODEV) ? -EPROBE_DEFER : ret;
141	}
142	regulator_put(regulator);
143
144	/* The FUSB302 uses the irq at index 1 and is the only irq user */
145	fusb302_irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 1);
146	if (fusb302_irq < 0) {
147		if (fusb302_irq != -EPROBE_DEFER)
148			dev_err(dev, "Error getting FUSB302 irq\n");
149		return fusb302_irq;
150	}
151
152	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
153	if (!data)
154		return -ENOMEM;
155
156	/* Work around BIOS bug, see comment on cht_int33fe_find_max17047 */
157	max17047 = cht_int33fe_find_max17047();
158	if (max17047) {
159		/* Pre-existing i2c-client for the max17047, add device-props */
160		ret = device_add_properties(&max17047->dev, max17047_props);
161		if (ret)
162			return ret;
163		/* And re-probe to get the new device-props applied. */
164		ret = device_reprobe(&max17047->dev);
165		if (ret)
166			dev_warn(dev, "Reprobing max17047 error: %d\n", ret);
167	} else {
168		memset(&board_info, 0, sizeof(board_info));
169		strlcpy(board_info.type, "max17047", I2C_NAME_SIZE);
170		board_info.dev_name = "max17047";
171		board_info.properties = max17047_props;
172		data->max17047 = i2c_acpi_new_device(dev, 1, &board_info);
173		if (!data->max17047)
174			return -EPROBE_DEFER; /* Wait for i2c-adapter to load */
175	}
176
177	data->connections[0].endpoint[0] = "i2c-fusb302";
178	data->connections[0].endpoint[1] = "i2c-pi3usb30532";
179	data->connections[0].id = "typec-switch";
180	data->connections[1].endpoint[0] = "i2c-fusb302";
181	data->connections[1].endpoint[1] = "i2c-pi3usb30532";
182	data->connections[1].id = "typec-mux";
183	data->connections[2].endpoint[0] = "i2c-fusb302";
184	data->connections[2].endpoint[1] = "intel_xhci_usb_sw-role-switch";
185	data->connections[2].id = "usb-role-switch";
186
187	device_connection_add(&data->connections[0]);
188	device_connection_add(&data->connections[1]);
189	device_connection_add(&data->connections[2]);
190
191	memset(&board_info, 0, sizeof(board_info));
192	strlcpy(board_info.type, "typec_fusb302", I2C_NAME_SIZE);
193	board_info.dev_name = "fusb302";
194	board_info.properties = fusb302_props;
195	board_info.irq = fusb302_irq;
196
197	data->fusb302 = i2c_acpi_new_device(dev, 2, &board_info);
198	if (!data->fusb302)
199		goto out_unregister_max17047;
200
201	memset(&board_info, 0, sizeof(board_info));
202	board_info.dev_name = "pi3usb30532";
203	strlcpy(board_info.type, "pi3usb30532", I2C_NAME_SIZE);
204
205	data->pi3usb30532 = i2c_acpi_new_device(dev, 3, &board_info);
206	if (!data->pi3usb30532)
207		goto out_unregister_fusb302;
208
209	i2c_set_clientdata(client, data);
210
211	return 0;
212
213out_unregister_fusb302:
214	i2c_unregister_device(data->fusb302);
215
216out_unregister_max17047:
217	if (data->max17047)
218		i2c_unregister_device(data->max17047);
219
220	device_connection_remove(&data->connections[2]);
221	device_connection_remove(&data->connections[1]);
222	device_connection_remove(&data->connections[0]);
223
224	return -EPROBE_DEFER; /* Wait for the i2c-adapter to load */
225}
226
227static int cht_int33fe_remove(struct i2c_client *i2c)
228{
229	struct cht_int33fe_data *data = i2c_get_clientdata(i2c);
230
231	i2c_unregister_device(data->pi3usb30532);
232	i2c_unregister_device(data->fusb302);
233	if (data->max17047)
234		i2c_unregister_device(data->max17047);
235
236	device_connection_remove(&data->connections[2]);
237	device_connection_remove(&data->connections[1]);
238	device_connection_remove(&data->connections[0]);
239
240	return 0;
241}
242
243static const struct i2c_device_id cht_int33fe_i2c_id[] = {
244	{ }
245};
246MODULE_DEVICE_TABLE(i2c, cht_int33fe_i2c_id);
247
248static const struct acpi_device_id cht_int33fe_acpi_ids[] = {
249	{ "INT33FE", },
250	{ }
251};
252MODULE_DEVICE_TABLE(acpi, cht_int33fe_acpi_ids);
253
254static struct i2c_driver cht_int33fe_driver = {
255	.driver	= {
256		.name = "Intel Cherry Trail ACPI INT33FE driver",
257		.acpi_match_table = ACPI_PTR(cht_int33fe_acpi_ids),
258	},
259	.probe_new = cht_int33fe_probe,
260	.remove = cht_int33fe_remove,
261	.id_table = cht_int33fe_i2c_id,
262	.disable_i2c_core_irq_mapping = true,
263};
264
265module_i2c_driver(cht_int33fe_driver);
266
267MODULE_DESCRIPTION("Intel Cherry Trail ACPI INT33FE pseudo device driver");
268MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
269MODULE_LICENSE("GPL");