1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Driver for TI BQ32000 RTC.
  4 *
  5 * Copyright (C) 2009 Semihalf.
  6 * Copyright (C) 2014 Pavel Machek <pavel@denx.de>
  7 *
 
 
 
 
  8 * You can get hardware description at
  9 * https://www.ti.com/lit/ds/symlink/bq32000.pdf
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/i2c.h>
 14#include <linux/rtc.h>
 15#include <linux/init.h>
 16#include <linux/kstrtox.h>
 17#include <linux/errno.h>
 18#include <linux/bcd.h>
 19
 20#define BQ32K_SECONDS		0x00	/* Seconds register address */
 21#define BQ32K_SECONDS_MASK	0x7F	/* Mask over seconds value */
 22#define BQ32K_STOP		0x80	/* Oscillator Stop flat */
 23
 24#define BQ32K_MINUTES		0x01	/* Minutes register address */
 25#define BQ32K_MINUTES_MASK	0x7F	/* Mask over minutes value */
 26#define BQ32K_OF		0x80	/* Oscillator Failure flag */
 27
 28#define BQ32K_HOURS_MASK	0x3F	/* Mask over hours value */
 29#define BQ32K_CENT		0x40	/* Century flag */
 30#define BQ32K_CENT_EN		0x80	/* Century flag enable bit */
 31
 32#define BQ32K_CALIBRATION	0x07	/* CAL_CFG1, calibration and control */
 33#define BQ32K_TCH2		0x08	/* Trickle charge enable */
 34#define BQ32K_CFG2		0x09	/* Trickle charger control */
 35#define BQ32K_TCFE		BIT(6)	/* Trickle charge FET bypass */
 36
 37#define MAX_LEN			10	/* Maximum number of consecutive
 38					 * register for this particular RTC.
 39					 */
 40
 41struct bq32k_regs {
 42	uint8_t		seconds;
 43	uint8_t		minutes;
 44	uint8_t		cent_hours;
 45	uint8_t		day;
 46	uint8_t		date;
 47	uint8_t		month;
 48	uint8_t		years;
 49};
 50
 51static struct i2c_driver bq32k_driver;
 52
 53static int bq32k_read(struct device *dev, void *data, uint8_t off, uint8_t len)
 54{
 55	struct i2c_client *client = to_i2c_client(dev);
 56	struct i2c_msg msgs[] = {
 57		{
 58			.addr = client->addr,
 59			.flags = 0,
 60			.len = 1,
 61			.buf = &off,
 62		}, {
 63			.addr = client->addr,
 64			.flags = I2C_M_RD,
 65			.len = len,
 66			.buf = data,
 67		}
 68	};
 69
 70	if (i2c_transfer(client->adapter, msgs, 2) == 2)
 71		return 0;
 72
 73	return -EIO;
 74}
 75
 76static int bq32k_write(struct device *dev, void *data, uint8_t off, uint8_t len)
 77{
 78	struct i2c_client *client = to_i2c_client(dev);
 79	uint8_t buffer[MAX_LEN + 1];
 80
 81	buffer[0] = off;
 82	memcpy(&buffer[1], data, len);
 83
 84	if (i2c_master_send(client, buffer, len + 1) == len + 1)
 85		return 0;
 86
 87	return -EIO;
 88}
 89
 90static int bq32k_rtc_read_time(struct device *dev, struct rtc_time *tm)
 91{
 92	struct bq32k_regs regs;
 93	int error;
 94
 95	error = bq32k_read(dev, &regs, 0, sizeof(regs));
 96	if (error)
 97		return error;
 98
 99	/*
100	 * In case of oscillator failure, the register contents should be
101	 * considered invalid. The flag is cleared the next time the RTC is set.
102	 */
103	if (regs.minutes & BQ32K_OF)
104		return -EINVAL;
105
106	tm->tm_sec = bcd2bin(regs.seconds & BQ32K_SECONDS_MASK);
107	tm->tm_min = bcd2bin(regs.minutes & BQ32K_MINUTES_MASK);
108	tm->tm_hour = bcd2bin(regs.cent_hours & BQ32K_HOURS_MASK);
109	tm->tm_mday = bcd2bin(regs.date);
110	tm->tm_wday = bcd2bin(regs.day) - 1;
111	tm->tm_mon = bcd2bin(regs.month) - 1;
112	tm->tm_year = bcd2bin(regs.years) +
113				((regs.cent_hours & BQ32K_CENT) ? 100 : 0);
114
115	return 0;
116}
117
118static int bq32k_rtc_set_time(struct device *dev, struct rtc_time *tm)
119{
120	struct bq32k_regs regs;
121
122	regs.seconds = bin2bcd(tm->tm_sec);
123	regs.minutes = bin2bcd(tm->tm_min);
124	regs.cent_hours = bin2bcd(tm->tm_hour) | BQ32K_CENT_EN;
125	regs.day = bin2bcd(tm->tm_wday + 1);
126	regs.date = bin2bcd(tm->tm_mday);
127	regs.month = bin2bcd(tm->tm_mon + 1);
128
129	if (tm->tm_year >= 100) {
130		regs.cent_hours |= BQ32K_CENT;
131		regs.years = bin2bcd(tm->tm_year - 100);
132	} else
133		regs.years = bin2bcd(tm->tm_year);
134
135	return bq32k_write(dev, &regs, 0, sizeof(regs));
136}
137
138static const struct rtc_class_ops bq32k_rtc_ops = {
139	.read_time	= bq32k_rtc_read_time,
140	.set_time	= bq32k_rtc_set_time,
141};
142
143static int trickle_charger_of_init(struct device *dev, struct device_node *node)
144{
145	unsigned char reg;
146	int error;
147	u32 ohms = 0;
148
149	if (of_property_read_u32(node, "trickle-resistor-ohms" , &ohms))
150		return 0;
151
152	switch (ohms) {
153	case 180+940:
154		/*
155		 * TCHE[3:0] == 0x05, TCH2 == 1, TCFE == 0 (charging
156		 * over diode and 940ohm resistor)
157		 */
158
159		if (of_property_read_bool(node, "trickle-diode-disable")) {
160			dev_err(dev, "diode and resistor mismatch\n");
161			return -EINVAL;
162		}
163		reg = 0x05;
164		break;
165
166	case 180+20000:
167		/* diode disabled */
168
169		if (!of_property_read_bool(node, "trickle-diode-disable")) {
170			dev_err(dev, "bq32k: diode and resistor mismatch\n");
171			return -EINVAL;
172		}
173		reg = 0x45;
174		break;
175
176	default:
177		dev_err(dev, "invalid resistor value (%d)\n", ohms);
178		return -EINVAL;
179	}
180
181	error = bq32k_write(dev, &reg, BQ32K_CFG2, 1);
182	if (error)
183		return error;
184
185	reg = 0x20;
186	error = bq32k_write(dev, &reg, BQ32K_TCH2, 1);
187	if (error)
188		return error;
189
190	dev_info(dev, "Enabled trickle RTC battery charge.\n");
191	return 0;
192}
193
194static ssize_t bq32k_sysfs_show_tricklecharge_bypass(struct device *dev,
195					       struct device_attribute *attr,
196					       char *buf)
197{
198	int reg, error;
199
200	error = bq32k_read(dev, &reg, BQ32K_CFG2, 1);
201	if (error)
202		return error;
203
204	return sprintf(buf, "%d\n", (reg & BQ32K_TCFE) ? 1 : 0);
205}
206
207static ssize_t bq32k_sysfs_store_tricklecharge_bypass(struct device *dev,
208						struct device_attribute *attr,
209						const char *buf, size_t count)
210{
211	int reg, enable, error;
212
213	if (kstrtoint(buf, 0, &enable))
214		return -EINVAL;
215
216	error = bq32k_read(dev, &reg, BQ32K_CFG2, 1);
217	if (error)
218		return error;
219
220	if (enable) {
221		reg |= BQ32K_TCFE;
222		error = bq32k_write(dev, &reg, BQ32K_CFG2, 1);
223		if (error)
224			return error;
225
226		dev_info(dev, "Enabled trickle charge FET bypass.\n");
227	} else {
228		reg &= ~BQ32K_TCFE;
229		error = bq32k_write(dev, &reg, BQ32K_CFG2, 1);
230		if (error)
231			return error;
232
233		dev_info(dev, "Disabled trickle charge FET bypass.\n");
234	}
235
236	return count;
237}
238
239static DEVICE_ATTR(trickle_charge_bypass, 0644,
240		   bq32k_sysfs_show_tricklecharge_bypass,
241		   bq32k_sysfs_store_tricklecharge_bypass);
242
243static int bq32k_sysfs_register(struct device *dev)
244{
245	return device_create_file(dev, &dev_attr_trickle_charge_bypass);
246}
247
248static void bq32k_sysfs_unregister(struct device *dev)
249{
250	device_remove_file(dev, &dev_attr_trickle_charge_bypass);
251}
252
253static int bq32k_probe(struct i2c_client *client)
 
254{
255	struct device *dev = &client->dev;
256	struct rtc_device *rtc;
257	uint8_t reg;
258	int error;
259
260	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
261		return -ENODEV;
262
263	/* Check Oscillator Stop flag */
264	error = bq32k_read(dev, &reg, BQ32K_SECONDS, 1);
265	if (!error && (reg & BQ32K_STOP)) {
266		dev_warn(dev, "Oscillator was halted. Restarting...\n");
267		reg &= ~BQ32K_STOP;
268		error = bq32k_write(dev, &reg, BQ32K_SECONDS, 1);
269	}
270	if (error)
271		return error;
272
273	/* Check Oscillator Failure flag */
274	error = bq32k_read(dev, &reg, BQ32K_MINUTES, 1);
275	if (error)
276		return error;
277	if (reg & BQ32K_OF)
278		dev_warn(dev, "Oscillator Failure. Check RTC battery.\n");
279
280	if (client->dev.of_node)
281		trickle_charger_of_init(dev, client->dev.of_node);
282
283	rtc = devm_rtc_device_register(&client->dev, bq32k_driver.driver.name,
284						&bq32k_rtc_ops, THIS_MODULE);
285	if (IS_ERR(rtc))
286		return PTR_ERR(rtc);
287
288	error = bq32k_sysfs_register(&client->dev);
289	if (error) {
290		dev_err(&client->dev,
291			"Unable to create sysfs entries for rtc bq32000\n");
292		return error;
293	}
294
295
296	i2c_set_clientdata(client, rtc);
297
298	return 0;
299}
300
301static void bq32k_remove(struct i2c_client *client)
302{
303	bq32k_sysfs_unregister(&client->dev);
 
 
304}
305
306static const struct i2c_device_id bq32k_id[] = {
307	{ "bq32000", 0 },
308	{ }
309};
310MODULE_DEVICE_TABLE(i2c, bq32k_id);
311
312static const __maybe_unused struct of_device_id bq32k_of_match[] = {
313	{ .compatible = "ti,bq32000" },
314	{ }
315};
316MODULE_DEVICE_TABLE(of, bq32k_of_match);
317
318static struct i2c_driver bq32k_driver = {
319	.driver = {
320		.name	= "bq32k",
321		.of_match_table = of_match_ptr(bq32k_of_match),
322	},
323	.probe_new	= bq32k_probe,
324	.remove		= bq32k_remove,
325	.id_table	= bq32k_id,
326};
327
328module_i2c_driver(bq32k_driver);
329
330MODULE_AUTHOR("Semihalf, Piotr Ziecik <kosmo@semihalf.com>");
331MODULE_DESCRIPTION("TI BQ32000 I2C RTC driver");
332MODULE_LICENSE("GPL");

 
  1/*
  2 * Driver for TI BQ32000 RTC.
  3 *
  4 * Copyright (C) 2009 Semihalf.
  5 * Copyright (C) 2014 Pavel Machek <pavel@denx.de>
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License version 2 as
  9 * published by the Free Software Foundation.
 10 *
 11 * You can get hardware description at
 12 * http://www.ti.com/lit/ds/symlink/bq32000.pdf
 13 */
 14
 15#include <linux/module.h>
 16#include <linux/i2c.h>
 17#include <linux/rtc.h>
 18#include <linux/init.h>
 
 19#include <linux/errno.h>
 20#include <linux/bcd.h>
 21
 22#define BQ32K_SECONDS		0x00	/* Seconds register address */
 23#define BQ32K_SECONDS_MASK	0x7F	/* Mask over seconds value */
 24#define BQ32K_STOP		0x80	/* Oscillator Stop flat */
 25
 26#define BQ32K_MINUTES		0x01	/* Minutes register address */
 27#define BQ32K_MINUTES_MASK	0x7F	/* Mask over minutes value */
 28#define BQ32K_OF		0x80	/* Oscillator Failure flag */
 29
 30#define BQ32K_HOURS_MASK	0x3F	/* Mask over hours value */
 31#define BQ32K_CENT		0x40	/* Century flag */
 32#define BQ32K_CENT_EN		0x80	/* Century flag enable bit */
 33
 34#define BQ32K_CALIBRATION	0x07	/* CAL_CFG1, calibration and control */
 35#define BQ32K_TCH2		0x08	/* Trickle charge enable */
 36#define BQ32K_CFG2		0x09	/* Trickle charger control */
 37#define BQ32K_TCFE		BIT(6)	/* Trickle charge FET bypass */
 38
 39#define MAX_LEN			10	/* Maximum number of consecutive
 40					 * register for this particular RTC.
 41					 */
 42
 43struct bq32k_regs {
 44	uint8_t		seconds;
 45	uint8_t		minutes;
 46	uint8_t		cent_hours;
 47	uint8_t		day;
 48	uint8_t		date;
 49	uint8_t		month;
 50	uint8_t		years;
 51};
 52
 53static struct i2c_driver bq32k_driver;
 54
 55static int bq32k_read(struct device *dev, void *data, uint8_t off, uint8_t len)
 56{
 57	struct i2c_client *client = to_i2c_client(dev);
 58	struct i2c_msg msgs[] = {
 59		{
 60			.addr = client->addr,
 61			.flags = 0,
 62			.len = 1,
 63			.buf = &off,
 64		}, {
 65			.addr = client->addr,
 66			.flags = I2C_M_RD,
 67			.len = len,
 68			.buf = data,
 69		}
 70	};
 71
 72	if (i2c_transfer(client->adapter, msgs, 2) == 2)
 73		return 0;
 74
 75	return -EIO;
 76}
 77
 78static int bq32k_write(struct device *dev, void *data, uint8_t off, uint8_t len)
 79{
 80	struct i2c_client *client = to_i2c_client(dev);
 81	uint8_t buffer[MAX_LEN + 1];
 82
 83	buffer[0] = off;
 84	memcpy(&buffer[1], data, len);
 85
 86	if (i2c_master_send(client, buffer, len + 1) == len + 1)
 87		return 0;
 88
 89	return -EIO;
 90}
 91
 92static int bq32k_rtc_read_time(struct device *dev, struct rtc_time *tm)
 93{
 94	struct bq32k_regs regs;
 95	int error;
 96
 97	error = bq32k_read(dev, &regs, 0, sizeof(regs));
 98	if (error)
 99		return error;
100
101	/*
102	 * In case of oscillator failure, the register contents should be
103	 * considered invalid. The flag is cleared the next time the RTC is set.
104	 */
105	if (regs.minutes & BQ32K_OF)
106		return -EINVAL;
107
108	tm->tm_sec = bcd2bin(regs.seconds & BQ32K_SECONDS_MASK);
109	tm->tm_min = bcd2bin(regs.minutes & BQ32K_MINUTES_MASK);
110	tm->tm_hour = bcd2bin(regs.cent_hours & BQ32K_HOURS_MASK);
111	tm->tm_mday = bcd2bin(regs.date);
112	tm->tm_wday = bcd2bin(regs.day) - 1;
113	tm->tm_mon = bcd2bin(regs.month) - 1;
114	tm->tm_year = bcd2bin(regs.years) +
115				((regs.cent_hours & BQ32K_CENT) ? 100 : 0);
116
117	return 0;
118}
119
120static int bq32k_rtc_set_time(struct device *dev, struct rtc_time *tm)
121{
122	struct bq32k_regs regs;
123
124	regs.seconds = bin2bcd(tm->tm_sec);
125	regs.minutes = bin2bcd(tm->tm_min);
126	regs.cent_hours = bin2bcd(tm->tm_hour) | BQ32K_CENT_EN;
127	regs.day = bin2bcd(tm->tm_wday + 1);
128	regs.date = bin2bcd(tm->tm_mday);
129	regs.month = bin2bcd(tm->tm_mon + 1);
130
131	if (tm->tm_year >= 100) {
132		regs.cent_hours |= BQ32K_CENT;
133		regs.years = bin2bcd(tm->tm_year - 100);
134	} else
135		regs.years = bin2bcd(tm->tm_year);
136
137	return bq32k_write(dev, &regs, 0, sizeof(regs));
138}
139
140static const struct rtc_class_ops bq32k_rtc_ops = {
141	.read_time	= bq32k_rtc_read_time,
142	.set_time	= bq32k_rtc_set_time,
143};
144
145static int trickle_charger_of_init(struct device *dev, struct device_node *node)
146{
147	unsigned char reg;
148	int error;
149	u32 ohms = 0;
150
151	if (of_property_read_u32(node, "trickle-resistor-ohms" , &ohms))
152		return 0;
153
154	switch (ohms) {
155	case 180+940:
156		/*
157		 * TCHE[3:0] == 0x05, TCH2 == 1, TCFE == 0 (charging
158		 * over diode and 940ohm resistor)
159		 */
160
161		if (of_property_read_bool(node, "trickle-diode-disable")) {
162			dev_err(dev, "diode and resistor mismatch\n");
163			return -EINVAL;
164		}
165		reg = 0x05;
166		break;
167
168	case 180+20000:
169		/* diode disabled */
170
171		if (!of_property_read_bool(node, "trickle-diode-disable")) {
172			dev_err(dev, "bq32k: diode and resistor mismatch\n");
173			return -EINVAL;
174		}
175		reg = 0x45;
176		break;
177
178	default:
179		dev_err(dev, "invalid resistor value (%d)\n", ohms);
180		return -EINVAL;
181	}
182
183	error = bq32k_write(dev, &reg, BQ32K_CFG2, 1);
184	if (error)
185		return error;
186
187	reg = 0x20;
188	error = bq32k_write(dev, &reg, BQ32K_TCH2, 1);
189	if (error)
190		return error;
191
192	dev_info(dev, "Enabled trickle RTC battery charge.\n");
193	return 0;
194}
195
196static ssize_t bq32k_sysfs_show_tricklecharge_bypass(struct device *dev,
197					       struct device_attribute *attr,
198					       char *buf)
199{
200	int reg, error;
201
202	error = bq32k_read(dev, &reg, BQ32K_CFG2, 1);
203	if (error)
204		return error;
205
206	return sprintf(buf, "%d\n", (reg & BQ32K_TCFE) ? 1 : 0);
207}
208
209static ssize_t bq32k_sysfs_store_tricklecharge_bypass(struct device *dev,
210						struct device_attribute *attr,
211						const char *buf, size_t count)
212{
213	int reg, enable, error;
214
215	if (kstrtoint(buf, 0, &enable))
216		return -EINVAL;
217
218	error = bq32k_read(dev, &reg, BQ32K_CFG2, 1);
219	if (error)
220		return error;
221
222	if (enable) {
223		reg |= BQ32K_TCFE;
224		error = bq32k_write(dev, &reg, BQ32K_CFG2, 1);
225		if (error)
226			return error;
227
228		dev_info(dev, "Enabled trickle charge FET bypass.\n");
229	} else {
230		reg &= ~BQ32K_TCFE;
231		error = bq32k_write(dev, &reg, BQ32K_CFG2, 1);
232		if (error)
233			return error;
234
235		dev_info(dev, "Disabled trickle charge FET bypass.\n");
236	}
237
238	return count;
239}
240
241static DEVICE_ATTR(trickle_charge_bypass, 0644,
242		   bq32k_sysfs_show_tricklecharge_bypass,
243		   bq32k_sysfs_store_tricklecharge_bypass);
244
245static int bq32k_sysfs_register(struct device *dev)
246{
247	return device_create_file(dev, &dev_attr_trickle_charge_bypass);
248}
249
250static void bq32k_sysfs_unregister(struct device *dev)
251{
252	device_remove_file(dev, &dev_attr_trickle_charge_bypass);
253}
254
255static int bq32k_probe(struct i2c_client *client,
256				const struct i2c_device_id *id)
257{
258	struct device *dev = &client->dev;
259	struct rtc_device *rtc;
260	uint8_t reg;
261	int error;
262
263	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
264		return -ENODEV;
265
266	/* Check Oscillator Stop flag */
267	error = bq32k_read(dev, &reg, BQ32K_SECONDS, 1);
268	if (!error && (reg & BQ32K_STOP)) {
269		dev_warn(dev, "Oscillator was halted. Restarting...\n");
270		reg &= ~BQ32K_STOP;
271		error = bq32k_write(dev, &reg, BQ32K_SECONDS, 1);
272	}
273	if (error)
274		return error;
275
276	/* Check Oscillator Failure flag */
277	error = bq32k_read(dev, &reg, BQ32K_MINUTES, 1);
278	if (error)
279		return error;
280	if (reg & BQ32K_OF)
281		dev_warn(dev, "Oscillator Failure. Check RTC battery.\n");
282
283	if (client->dev.of_node)
284		trickle_charger_of_init(dev, client->dev.of_node);
285
286	rtc = devm_rtc_device_register(&client->dev, bq32k_driver.driver.name,
287						&bq32k_rtc_ops, THIS_MODULE);
288	if (IS_ERR(rtc))
289		return PTR_ERR(rtc);
290
291	error = bq32k_sysfs_register(&client->dev);
292	if (error) {
293		dev_err(&client->dev,
294			"Unable to create sysfs entries for rtc bq32000\n");
295		return error;
296	}
297
298
299	i2c_set_clientdata(client, rtc);
300
301	return 0;
302}
303
304static int bq32k_remove(struct i2c_client *client)
305{
306	bq32k_sysfs_unregister(&client->dev);
307
308	return 0;
309}
310
311static const struct i2c_device_id bq32k_id[] = {
312	{ "bq32000", 0 },
313	{ }
314};
315MODULE_DEVICE_TABLE(i2c, bq32k_id);
316
317static const struct of_device_id bq32k_of_match[] = {
318	{ .compatible = "ti,bq32000" },
319	{ }
320};
321MODULE_DEVICE_TABLE(of, bq32k_of_match);
322
323static struct i2c_driver bq32k_driver = {
324	.driver = {
325		.name	= "bq32k",
326		.of_match_table = of_match_ptr(bq32k_of_match),
327	},
328	.probe		= bq32k_probe,
329	.remove		= bq32k_remove,
330	.id_table	= bq32k_id,
331};
332
333module_i2c_driver(bq32k_driver);
334
335MODULE_AUTHOR("Semihalf, Piotr Ziecik <kosmo@semihalf.com>");
336MODULE_DESCRIPTION("TI BQ32000 I2C RTC driver");
337MODULE_LICENSE("GPL");