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PavithraUdayakumar-adialexandrebelloni
PavithraUdayakumar-adi
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alexandrebelloni
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rtc: max31335: Add driver support for max31331
MAX31331 is an ultra-low-power, I2C Real-Time Clock RTC. Signed-off-by: PavithraUdayakumar-adi <pavithra.u@analog.com> Link: https://lore.kernel.org/r/20250217-add_support_max31331_fix_8-v1-2-16ebcfc02336@analog.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
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‎drivers/rtc/rtc-max31335.c‎

Lines changed: 122 additions & 43 deletions
Original file line numberDiff line numberDiff line change
@@ -184,31 +184,91 @@
184184
#define MAX31335_RAM_SIZE 32
185185
#define MAX31335_TIME_SIZE 0x07
186186

187+
/* MAX31331 Register Map */
188+
#define MAX31331_RTC_CONFIG2 0x04
189+
187190
#define clk_hw_to_max31335(_hw) container_of(_hw, struct max31335_data, clkout)
188191

192+
/* Supported Maxim RTC */
193+
enum max_rtc_ids {
194+
ID_MAX31331,
195+
ID_MAX31335,
196+
MAX_RTC_ID_NR
197+
};
198+
199+
struct chip_desc {
200+
u8 sec_reg;
201+
u8 alarm1_sec_reg;
202+
203+
u8 int_en_reg;
204+
u8 int_status_reg;
205+
206+
u8 ram_reg;
207+
u8 ram_size;
208+
209+
u8 temp_reg;
210+
211+
u8 trickle_reg;
212+
213+
u8 clkout_reg;
214+
215+
enum max_rtc_ids id;
216+
};
217+
189218
struct max31335_data {
190219
struct regmap *regmap;
191220
struct rtc_device *rtc;
192221
struct clk_hw clkout;
222+
struct clk *clkin;
223+
const struct chip_desc *chip;
224+
int irq;
193225
};
194226

195227
static const int max31335_clkout_freq[] = { 1, 64, 1024, 32768 };
196228

229+
static const struct chip_desc chip[MAX_RTC_ID_NR] = {
230+
[ID_MAX31331] = {
231+
.id = ID_MAX31331,
232+
.int_en_reg = 0x01,
233+
.int_status_reg = 0x00,
234+
.sec_reg = 0x08,
235+
.alarm1_sec_reg = 0x0F,
236+
.ram_reg = 0x20,
237+
.ram_size = 32,
238+
.trickle_reg = 0x1B,
239+
.clkout_reg = 0x04,
240+
},
241+
[ID_MAX31335] = {
242+
.id = ID_MAX31335,
243+
.int_en_reg = 0x01,
244+
.int_status_reg = 0x00,
245+
.sec_reg = 0x0A,
246+
.alarm1_sec_reg = 0x11,
247+
.ram_reg = 0x40,
248+
.ram_size = 32,
249+
.temp_reg = 0x35,
250+
.trickle_reg = 0x1D,
251+
.clkout_reg = 0x06,
252+
},
253+
};
254+
197255
static const u16 max31335_trickle_resistors[] = {3000, 6000, 11000};
198256

199257
static bool max31335_volatile_reg(struct device *dev, unsigned int reg)
200258
{
259+
struct max31335_data *max31335 = dev_get_drvdata(dev);
260+
const struct chip_desc *chip = max31335->chip;
261+
201262
/* time keeping registers */
202-
if (reg >= MAX31335_SECONDS &&
203-
reg < MAX31335_SECONDS + MAX31335_TIME_SIZE)
263+
if (reg >= chip->sec_reg && reg < chip->sec_reg + MAX31335_TIME_SIZE)
204264
return true;
205265

206266
/* interrupt status register */
207-
if (reg == MAX31335_STATUS1)
267+
if (reg == chip->int_status_reg)
208268
return true;
209269

210-
/* temperature registers */
211-
if (reg == MAX31335_TEMP_DATA_MSB || reg == MAX31335_TEMP_DATA_LSB)
270+
/* temperature registers if valid */
271+
if (chip->temp_reg && (reg == chip->temp_reg || reg == chip->temp_reg + 1))
212272
return true;
213273

214274
return false;
@@ -227,7 +287,7 @@ static int max31335_read_time(struct device *dev, struct rtc_time *tm)
227287
u8 date[7];
228288
int ret;
229289

230-
ret = regmap_bulk_read(max31335->regmap, MAX31335_SECONDS, date,
290+
ret = regmap_bulk_read(max31335->regmap, max31335->chip->sec_reg, date,
231291
sizeof(date));
232292
if (ret)
233293
return ret;
@@ -262,7 +322,7 @@ static int max31335_set_time(struct device *dev, struct rtc_time *tm)
262322
if (tm->tm_year >= 200)
263323
date[5] |= FIELD_PREP(MAX31335_MONTH_CENTURY, 1);
264324

265-
return regmap_bulk_write(max31335->regmap, MAX31335_SECONDS, date,
325+
return regmap_bulk_write(max31335->regmap, max31335->chip->sec_reg, date,
266326
sizeof(date));
267327
}
268328

@@ -273,7 +333,7 @@ static int max31335_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
273333
struct rtc_time time;
274334
u8 regs[6];
275335

276-
ret = regmap_bulk_read(max31335->regmap, MAX31335_ALM1_SEC, regs,
336+
ret = regmap_bulk_read(max31335->regmap, max31335->chip->alarm1_sec_reg, regs,
277337
sizeof(regs));
278338
if (ret)
279339
return ret;
@@ -292,11 +352,11 @@ static int max31335_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
292352
if (time.tm_year >= 200)
293353
alrm->time.tm_year += 100;
294354

295-
ret = regmap_read(max31335->regmap, MAX31335_INT_EN1, &ctrl);
355+
ret = regmap_read(max31335->regmap, max31335->chip->int_en_reg, &ctrl);
296356
if (ret)
297357
return ret;
298358

299-
ret = regmap_read(max31335->regmap, MAX31335_STATUS1, &status);
359+
ret = regmap_read(max31335->regmap, max31335->chip->int_status_reg, &status);
300360
if (ret)
301361
return ret;
302362

@@ -320,18 +380,18 @@ static int max31335_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
320380
regs[4] = bin2bcd(alrm->time.tm_mon + 1);
321381
regs[5] = bin2bcd(alrm->time.tm_year % 100);
322382

323-
ret = regmap_bulk_write(max31335->regmap, MAX31335_ALM1_SEC,
383+
ret = regmap_bulk_write(max31335->regmap, max31335->chip->alarm1_sec_reg,
324384
regs, sizeof(regs));
325385
if (ret)
326386
return ret;
327387

328388
reg = FIELD_PREP(MAX31335_INT_EN1_A1IE, alrm->enabled);
329-
ret = regmap_update_bits(max31335->regmap, MAX31335_INT_EN1,
389+
ret = regmap_update_bits(max31335->regmap, max31335->chip->int_en_reg,
330390
MAX31335_INT_EN1_A1IE, reg);
331391
if (ret)
332392
return ret;
333393

334-
ret = regmap_update_bits(max31335->regmap, MAX31335_STATUS1,
394+
ret = regmap_update_bits(max31335->regmap, max31335->chip->int_status_reg,
335395
MAX31335_STATUS1_A1F, 0);
336396

337397
return 0;
@@ -341,23 +401,33 @@ static int max31335_alarm_irq_enable(struct device *dev, unsigned int enabled)
341401
{
342402
struct max31335_data *max31335 = dev_get_drvdata(dev);
343403

344-
return regmap_update_bits(max31335->regmap, MAX31335_INT_EN1,
404+
return regmap_update_bits(max31335->regmap, max31335->chip->int_en_reg,
345405
MAX31335_INT_EN1_A1IE, enabled);
346406
}
347407

348408
static irqreturn_t max31335_handle_irq(int irq, void *dev_id)
349409
{
350410
struct max31335_data *max31335 = dev_id;
351-
bool status;
352-
int ret;
411+
struct mutex *lock = &max31335->rtc->ops_lock;
412+
int ret, status;
353413

354-
ret = regmap_update_bits_check(max31335->regmap, MAX31335_STATUS1,
355-
MAX31335_STATUS1_A1F, 0, &status);
414+
mutex_lock(lock);
415+
416+
ret = regmap_read(max31335->regmap, max31335->chip->int_status_reg, &status);
356417
if (ret)
357-
return IRQ_HANDLED;
418+
goto exit;
419+
420+
if (FIELD_GET(MAX31335_STATUS1_A1F, status)) {
421+
ret = regmap_update_bits(max31335->regmap, max31335->chip->int_status_reg,
422+
MAX31335_STATUS1_A1F, 0);
423+
if (ret)
424+
goto exit;
358425

359-
if (status)
360426
rtc_update_irq(max31335->rtc, 1, RTC_AF | RTC_IRQF);
427+
}
428+
429+
exit:
430+
mutex_unlock(lock);
361431

362432
return IRQ_HANDLED;
363433
}
@@ -404,7 +474,7 @@ static int max31335_trickle_charger_setup(struct device *dev,
404474

405475
i = i + trickle_cfg;
406476

407-
return regmap_write(max31335->regmap, MAX31335_TRICKLE_REG,
477+
return regmap_write(max31335->regmap, max31335->chip->trickle_reg,
408478
FIELD_PREP(MAX31335_TRICKLE_REG_TRICKLE, i) |
409479
FIELD_PREP(MAX31335_TRICKLE_REG_EN_TRICKLE,
410480
chargeable));
@@ -418,7 +488,7 @@ static unsigned long max31335_clkout_recalc_rate(struct clk_hw *hw,
418488
unsigned int reg;
419489
int ret;
420490

421-
ret = regmap_read(max31335->regmap, MAX31335_RTC_CONFIG2, &reg);
491+
ret = regmap_read(max31335->regmap, max31335->chip->clkout_reg, &reg);
422492
if (ret)
423493
return 0;
424494

@@ -449,23 +519,23 @@ static int max31335_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
449519
ARRAY_SIZE(max31335_clkout_freq));
450520
freq_mask = __roundup_pow_of_two(ARRAY_SIZE(max31335_clkout_freq)) - 1;
451521

452-
return regmap_update_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
453-
freq_mask, index);
522+
return regmap_update_bits(max31335->regmap, max31335->chip->clkout_reg,
523+
freq_mask, index);
454524
}
455525

456526
static int max31335_clkout_enable(struct clk_hw *hw)
457527
{
458528
struct max31335_data *max31335 = clk_hw_to_max31335(hw);
459529

460-
return regmap_set_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
461-
MAX31335_RTC_CONFIG2_ENCLKO);
530+
return regmap_set_bits(max31335->regmap, max31335->chip->clkout_reg,
531+
MAX31335_RTC_CONFIG2_ENCLKO);
462532
}
463533

464534
static void max31335_clkout_disable(struct clk_hw *hw)
465535
{
466536
struct max31335_data *max31335 = clk_hw_to_max31335(hw);
467537

468-
regmap_clear_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
538+
regmap_clear_bits(max31335->regmap, max31335->chip->clkout_reg,
469539
MAX31335_RTC_CONFIG2_ENCLKO);
470540
}
471541

@@ -475,7 +545,7 @@ static int max31335_clkout_is_enabled(struct clk_hw *hw)
475545
unsigned int reg;
476546
int ret;
477547

478-
ret = regmap_read(max31335->regmap, MAX31335_RTC_CONFIG2, &reg);
548+
ret = regmap_read(max31335->regmap, max31335->chip->clkout_reg, &reg);
479549
if (ret)
480550
return ret;
481551

@@ -500,7 +570,7 @@ static int max31335_nvmem_reg_read(void *priv, unsigned int offset,
500570
void *val, size_t bytes)
501571
{
502572
struct max31335_data *max31335 = priv;
503-
unsigned int reg = MAX31335_TS0_SEC_1_128 + offset;
573+
unsigned int reg = max31335->chip->ram_reg + offset;
504574

505575
return regmap_bulk_read(max31335->regmap, reg, val, bytes);
506576
}
@@ -509,7 +579,7 @@ static int max31335_nvmem_reg_write(void *priv, unsigned int offset,
509579
void *val, size_t bytes)
510580
{
511581
struct max31335_data *max31335 = priv;
512-
unsigned int reg = MAX31335_TS0_SEC_1_128 + offset;
582+
unsigned int reg = max31335->chip->ram_reg + offset;
513583

514584
return regmap_bulk_write(max31335->regmap, reg, val, bytes);
515585
}
@@ -533,7 +603,7 @@ static int max31335_read_temp(struct device *dev, enum hwmon_sensor_types type,
533603
if (type != hwmon_temp || attr != hwmon_temp_input)
534604
return -EOPNOTSUPP;
535605

536-
ret = regmap_bulk_read(max31335->regmap, MAX31335_TEMP_DATA_MSB,
606+
ret = regmap_bulk_read(max31335->regmap, max31335->chip->temp_reg,
537607
reg, 2);
538608
if (ret)
539609
return ret;
@@ -577,8 +647,8 @@ static int max31335_clkout_register(struct device *dev)
577647
int ret;
578648

579649
if (!device_property_present(dev, "#clock-cells"))
580-
return regmap_clear_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
581-
MAX31335_RTC_CONFIG2_ENCLKO);
650+
return regmap_clear_bits(max31335->regmap, max31335->chip->clkout_reg,
651+
MAX31335_RTC_CONFIG2_ENCLKO);
582652

583653
max31335->clkout.init = &max31335_clk_init;
584654

@@ -605,6 +675,7 @@ static int max31335_probe(struct i2c_client *client)
605675
#if IS_REACHABLE(HWMON)
606676
struct device *hwmon;
607677
#endif
678+
const struct chip_desc *match;
608679
int ret;
609680

610681
max31335 = devm_kzalloc(&client->dev, sizeof(*max31335), GFP_KERNEL);
@@ -616,7 +687,10 @@ static int max31335_probe(struct i2c_client *client)
616687
return PTR_ERR(max31335->regmap);
617688

618689
i2c_set_clientdata(client, max31335);
619-
690+
match = i2c_get_match_data(client);
691+
if (!match)
692+
return -ENODEV;
693+
max31335->chip = match;
620694
max31335->rtc = devm_rtc_allocate_device(&client->dev);
621695
if (IS_ERR(max31335->rtc))
622696
return PTR_ERR(max31335->rtc);
@@ -639,6 +713,8 @@ static int max31335_probe(struct i2c_client *client)
639713
dev_warn(&client->dev,
640714
"unable to request IRQ, alarm max31335 disabled\n");
641715
client->irq = 0;
716+
} else {
717+
max31335->irq = client->irq;
642718
}
643719
}
644720

@@ -652,13 +728,13 @@ static int max31335_probe(struct i2c_client *client)
652728
"cannot register rtc nvmem\n");
653729

654730
#if IS_REACHABLE(HWMON)
655-
hwmon = devm_hwmon_device_register_with_info(&client->dev, client->name,
656-
max31335,
657-
&max31335_chip_info,
658-
NULL);
659-
if (IS_ERR(hwmon))
660-
return dev_err_probe(&client->dev, PTR_ERR(hwmon),
661-
"cannot register hwmon device\n");
731+
if (max31335->chip->temp_reg) {
732+
hwmon = devm_hwmon_device_register_with_info(&client->dev, client->name, max31335,
733+
&max31335_chip_info, NULL);
734+
if (IS_ERR(hwmon))
735+
return dev_err_probe(&client->dev, PTR_ERR(hwmon),
736+
"cannot register hwmon device\n");
737+
}
662738
#endif
663739

664740
ret = max31335_trickle_charger_setup(&client->dev, max31335);
@@ -669,14 +745,16 @@ static int max31335_probe(struct i2c_client *client)
669745
}
670746

671747
static const struct i2c_device_id max31335_id[] = {
672-
{ "max31335" },
748+
{ "max31331", (kernel_ulong_t)&chip[ID_MAX31331] },
749+
{ "max31335", (kernel_ulong_t)&chip[ID_MAX31335] },
673750
{ }
674751
};
675752

676753
MODULE_DEVICE_TABLE(i2c, max31335_id);
677754

678755
static const struct of_device_id max31335_of_match[] = {
679-
{ .compatible = "adi,max31335" },
756+
{ .compatible = "adi,max31331", .data = &chip[ID_MAX31331] },
757+
{ .compatible = "adi,max31335", .data = &chip[ID_MAX31335] },
680758
{ }
681759
};
682760

@@ -693,5 +771,6 @@ static struct i2c_driver max31335_driver = {
693771
module_i2c_driver(max31335_driver);
694772

695773
MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
774+
MODULE_AUTHOR("Saket Kumar Purwar <Saket.Kumarpurwar@analog.com>");
696775
MODULE_DESCRIPTION("MAX31335 RTC driver");
697776
MODULE_LICENSE("GPL");

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