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SwaroopPKADISwaroopPKADI
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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: Swaroop Kukkillaya <Swaroop.PrakashKumar@analog.com>
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‎drivers/rtc/rtc-max31335.c

+121-40
Original file line numberDiff line numberDiff line change
@@ -184,31 +184,90 @@
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+
189216
struct max31335_data {
217+
enum max_rtc_ids id;
190218
struct regmap *regmap;
191219
struct rtc_device *rtc;
192220
struct clk_hw clkout;
221+
struct clk *clkin;
222+
const struct chip_desc *chip;
223+
int irq;
193224
};
194225

195226
static const int max31335_clkout_freq[] = { 1, 64, 1024, 32768 };
196227

228+
static const struct chip_desc chip[MAX_RTC_ID_NR] = {
229+
[ID_MAX31331] = {
230+
.int_en_reg = 0x01,
231+
.int_status_reg = 0x00,
232+
.sec_reg = 0x08,
233+
.alarm1_sec_reg = 0x0F,
234+
.ram_reg = 0x20,
235+
.ram_size = 32,
236+
.trickle_reg = 0x1B,
237+
.clkout_reg = 0x04,
238+
},
239+
[ID_MAX31335] = {
240+
.int_en_reg = 0x01,
241+
.int_status_reg = 0x00,
242+
.sec_reg = 0x0A,
243+
.alarm1_sec_reg = 0x11,
244+
.ram_reg = 0x40,
245+
.ram_size = 32,
246+
.temp_reg = 0x35,
247+
.trickle_reg = 0x1D,
248+
.clkout_reg = 0x06,
249+
},
250+
};
251+
197252
static const u16 max31335_trickle_resistors[] = {3000, 6000, 11000};
198253

199254
static bool max31335_volatile_reg(struct device *dev, unsigned int reg)
200255
{
256+
struct max31335_data *max31335 = dev_get_drvdata(dev);
257+
const struct chip_desc *chip = max31335->chip;
258+
201259
/* time keeping registers */
202-
if (reg >= MAX31335_SECONDS &&
203-
reg < MAX31335_SECONDS + MAX31335_TIME_SIZE)
260+
if (reg >= chip->sec_reg &&
261+
reg < chip->sec_reg + MAX31335_TIME_SIZE)
204262
return true;
205263

206264
/* interrupt status register */
207-
if (reg == MAX31335_STATUS1)
265+
if (reg == chip->int_status_reg)
208266
return true;
209267

210-
/* temperature registers */
211-
if (reg == MAX31335_TEMP_DATA_MSB || MAX31335_TEMP_DATA_LSB)
268+
/* temperature registers if valid*/
269+
if (chip->temp_reg &&
270+
(reg == chip->temp_reg || reg == chip->temp_reg + 1))
212271
return true;
213272

214273
return false;
@@ -227,7 +286,7 @@ static int max31335_read_time(struct device *dev, struct rtc_time *tm)
227286
u8 date[7];
228287
int ret;
229288

230-
ret = regmap_bulk_read(max31335->regmap, MAX31335_SECONDS, date,
289+
ret = regmap_bulk_read(max31335->regmap, max31335->chip->sec_reg, date,
231290
sizeof(date));
232291
if (ret)
233292
return ret;
@@ -262,7 +321,7 @@ static int max31335_set_time(struct device *dev, struct rtc_time *tm)
262321
if (tm->tm_year >= 200)
263322
date[5] |= FIELD_PREP(MAX31335_MONTH_CENTURY, 1);
264323

265-
return regmap_bulk_write(max31335->regmap, MAX31335_SECONDS, date,
324+
return regmap_bulk_write(max31335->regmap, max31335->chip->sec_reg, date,
266325
sizeof(date));
267326
}
268327

@@ -273,7 +332,7 @@ static int max31335_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
273332
struct rtc_time time;
274333
u8 regs[6];
275334

276-
ret = regmap_bulk_read(max31335->regmap, MAX31335_ALM1_SEC, regs,
335+
ret = regmap_bulk_read(max31335->regmap, max31335->chip->alarm1_sec_reg, regs,
277336
sizeof(regs));
278337
if (ret)
279338
return ret;
@@ -292,11 +351,11 @@ static int max31335_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
292351
if (time.tm_year >= 200)
293352
alrm->time.tm_year += 100;
294353

295-
ret = regmap_read(max31335->regmap, MAX31335_INT_EN1, &ctrl);
354+
ret = regmap_read(max31335->regmap, max31335->chip->int_en_reg, &ctrl);
296355
if (ret)
297356
return ret;
298357

299-
ret = regmap_read(max31335->regmap, MAX31335_STATUS1, &status);
358+
ret = regmap_read(max31335->regmap, max31335->chip->int_status_reg, &status);
300359
if (ret)
301360
return ret;
302361

@@ -320,18 +379,18 @@ static int max31335_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
320379
regs[4] = bin2bcd(alrm->time.tm_mon + 1);
321380
regs[5] = bin2bcd(alrm->time.tm_year % 100);
322381

323-
ret = regmap_bulk_write(max31335->regmap, MAX31335_ALM1_SEC,
382+
ret = regmap_bulk_write(max31335->regmap, max31335->chip->alarm1_sec_reg,
324383
regs, sizeof(regs));
325384
if (ret)
326385
return ret;
327386

328387
reg = FIELD_PREP(MAX31335_INT_EN1_A1IE, alrm->enabled);
329-
ret = regmap_update_bits(max31335->regmap, MAX31335_INT_EN1,
388+
ret = regmap_update_bits(max31335->regmap, max31335->chip->int_en_reg,
330389
MAX31335_INT_EN1_A1IE, reg);
331390
if (ret)
332391
return ret;
333392

334-
ret = regmap_update_bits(max31335->regmap, MAX31335_STATUS1,
393+
ret = regmap_update_bits(max31335->regmap, max31335->chip->int_status_reg,
335394
MAX31335_STATUS1_A1F, 0);
336395

337396
return 0;
@@ -341,7 +400,7 @@ static int max31335_alarm_irq_enable(struct device *dev, unsigned int enabled)
341400
{
342401
struct max31335_data *max31335 = dev_get_drvdata(dev);
343402

344-
return regmap_update_bits(max31335->regmap, MAX31335_INT_EN1,
403+
return regmap_update_bits(max31335->regmap, max31335->chip->int_en_reg,
345404
MAX31335_INT_EN1_A1IE, enabled);
346405
}
347406

@@ -353,12 +412,12 @@ static irqreturn_t max31335_handle_irq(int irq, void *dev_id)
353412

354413
mutex_lock(lock);
355414

356-
ret = regmap_read(max31335->regmap, MAX31335_STATUS1, &status);
415+
ret = regmap_read(max31335->regmap, max31335->chip->int_status_reg, &status);
357416
if (ret)
358417
goto exit;
359418

360419
if (FIELD_GET(MAX31335_STATUS1_A1F, status)) {
361-
ret = regmap_update_bits(max31335->regmap, MAX31335_STATUS1,
420+
ret = regmap_update_bits(max31335->regmap, max31335->chip->int_status_reg,
362421
MAX31335_STATUS1_A1F, 0);
363422
if (ret)
364423
goto exit;
@@ -414,7 +473,7 @@ static int max31335_trickle_charger_setup(struct device *dev,
414473

415474
i = i + trickle_cfg;
416475

417-
return regmap_write(max31335->regmap, MAX31335_TRICKLE_REG,
476+
return regmap_write(max31335->regmap, max31335->chip->trickle_reg,
418477
FIELD_PREP(MAX31335_TRICKLE_REG_TRICKLE, i) |
419478
FIELD_PREP(MAX31335_TRICKLE_REG_EN_TRICKLE,
420479
chargeable));
@@ -428,7 +487,7 @@ static unsigned long max31335_clkout_recalc_rate(struct clk_hw *hw,
428487
unsigned int reg;
429488
int ret;
430489

431-
ret = regmap_read(max31335->regmap, MAX31335_RTC_CONFIG2, &reg);
490+
ret = regmap_read(max31335->regmap, max31335->chip->clkout_reg, &reg);
432491
if (ret)
433492
return 0;
434493

@@ -454,29 +513,32 @@ static int max31335_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
454513
struct max31335_data *max31335 = clk_hw_to_max31335(hw);
455514
unsigned int freq_mask;
456515
int index;
516+
int ret;
457517

458518
index = find_closest(rate, max31335_clkout_freq,
459519
ARRAY_SIZE(max31335_clkout_freq));
460520
freq_mask = __roundup_pow_of_two(ARRAY_SIZE(max31335_clkout_freq)) - 1;
461521

462-
return regmap_update_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
463-
freq_mask, index);
522+
ret = regmap_update_bits(max31335->regmap, max31335->chip->clkout_reg,
523+
freq_mask, index);
524+
525+
return ret;
464526
}
465527

466528
static int max31335_clkout_enable(struct clk_hw *hw)
467529
{
468530
struct max31335_data *max31335 = clk_hw_to_max31335(hw);
469531

470-
return regmap_set_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
471-
MAX31335_RTC_CONFIG2_ENCLKO);
532+
return regmap_set_bits(max31335->regmap, max31335->chip->clkout_reg,
533+
MAX31335_RTC_CONFIG2_ENCLKO);
472534
}
473535

474536
static void max31335_clkout_disable(struct clk_hw *hw)
475537
{
476538
struct max31335_data *max31335 = clk_hw_to_max31335(hw);
477539

478-
regmap_clear_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
479-
MAX31335_RTC_CONFIG2_ENCLKO);
540+
regmap_clear_bits(max31335->regmap, max31335->chip->clkout_reg,
541+
MAX31335_RTC_CONFIG2_ENCLKO);
480542
}
481543

482544
static int max31335_clkout_is_enabled(struct clk_hw *hw)
@@ -485,7 +547,7 @@ static int max31335_clkout_is_enabled(struct clk_hw *hw)
485547
unsigned int reg;
486548
int ret;
487549

488-
ret = regmap_read(max31335->regmap, MAX31335_RTC_CONFIG2, &reg);
550+
ret = regmap_read(max31335->regmap, max31335->chip->clkout_reg, &reg);
489551
if (ret)
490552
return ret;
491553

@@ -510,7 +572,7 @@ static int max31335_nvmem_reg_read(void *priv, unsigned int offset,
510572
void *val, size_t bytes)
511573
{
512574
struct max31335_data *max31335 = priv;
513-
unsigned int reg = MAX31335_TS0_SEC_1_128 + offset;
575+
unsigned int reg = max31335->chip->ram_reg + offset;
514576

515577
return regmap_bulk_read(max31335->regmap, reg, val, bytes);
516578
}
@@ -519,7 +581,7 @@ static int max31335_nvmem_reg_write(void *priv, unsigned int offset,
519581
void *val, size_t bytes)
520582
{
521583
struct max31335_data *max31335 = priv;
522-
unsigned int reg = MAX31335_TS0_SEC_1_128 + offset;
584+
unsigned int reg = max31335->chip->ram_reg + offset;
523585

524586
return regmap_bulk_write(max31335->regmap, reg, val, bytes);
525587
}
@@ -543,7 +605,7 @@ static int max31335_read_temp(struct device *dev, enum hwmon_sensor_types type,
543605
if (type != hwmon_temp || attr != hwmon_temp_input)
544606
return -EOPNOTSUPP;
545607

546-
ret = regmap_bulk_read(max31335->regmap, MAX31335_TEMP_DATA_MSB,
608+
ret = regmap_bulk_read(max31335->regmap, max31335->chip->temp_reg,
547609
reg, 2);
548610
if (ret)
549611
return ret;
@@ -586,9 +648,10 @@ static int max31335_clkout_register(struct device *dev)
586648
struct max31335_data *max31335 = dev_get_drvdata(dev);
587649
int ret;
588650

589-
if (!device_property_present(dev, "#clock-cells"))
590-
return regmap_clear_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
591-
MAX31335_RTC_CONFIG2_ENCLKO);
651+
if (!device_property_present(dev, "#clock-cells")) {
652+
regmap_clear_bits(max31335->regmap, max31335->chip->clkout_reg,
653+
MAX31335_RTC_CONFIG2_ENCLKO);
654+
}
592655

593656
max31335->clkout.init = &max31335_clk_init;
594657

@@ -617,6 +680,7 @@ static int max31335_probe(struct i2c_client *client,
617680
#if IS_REACHABLE(HWMON)
618681
struct device *hwmon;
619682
#endif
683+
const void *match;
620684
int ret;
621685

622686
max31335 = devm_kzalloc(&client->dev, sizeof(*max31335), GFP_KERNEL);
@@ -629,6 +693,16 @@ static int max31335_probe(struct i2c_client *client,
629693

630694
i2c_set_clientdata(client, max31335);
631695

696+
match = device_get_match_data(&client->dev);
697+
if (match)
698+
max31335->chip = match;
699+
else if (id)
700+
max31335->chip = (struct chip_desc *)id->driver_data;
701+
else
702+
return -ENODEV;
703+
704+
max31335->id = max31335->chip - chip;
705+
632706
max31335->rtc = devm_rtc_allocate_device(&client->dev);
633707
if (IS_ERR(max31335->rtc))
634708
return PTR_ERR(max31335->rtc);
@@ -651,6 +725,8 @@ static int max31335_probe(struct i2c_client *client,
651725
dev_warn(&client->dev,
652726
"unable to request IRQ, alarm max31335 disabled\n");
653727
client->irq = 0;
728+
} else {
729+
max31335->irq = client->irq;
654730
}
655731
}
656732

@@ -664,13 +740,15 @@ static int max31335_probe(struct i2c_client *client,
664740
"cannot register rtc nvmem\n");
665741

666742
#if IS_REACHABLE(HWMON)
667-
hwmon = devm_hwmon_device_register_with_info(&client->dev, client->name,
668-
max31335,
669-
&max31335_chip_info,
670-
NULL);
671-
if (IS_ERR(hwmon))
672-
return dev_err_probe(&client->dev, PTR_ERR(hwmon),
673-
"cannot register hwmon device\n");
743+
if (max313xx->chip->temp_reg) {
744+
hwmon = devm_hwmon_device_register_with_info(&client->dev, client->name,
745+
max31335,
746+
&max31335_chip_info,
747+
NULL);
748+
if (IS_ERR(hwmon))
749+
return dev_err_probe(&client->dev, PTR_ERR(hwmon),
750+
"cannot register hwmon device\n");
751+
}
674752
#endif
675753

676754
ret = max31335_trickle_charger_setup(&client->dev, max31335);
@@ -681,14 +759,16 @@ static int max31335_probe(struct i2c_client *client,
681759
}
682760

683761
static const struct i2c_device_id max31335_id[] = {
684-
{ "max31335", 0 },
762+
{ "max31331", (kernel_ulong_t)&chip[ID_MAX31331] },
763+
{ "max31335", (kernel_ulong_t)&chip[ID_MAX31335] },
685764
{ }
686765
};
687766

688767
MODULE_DEVICE_TABLE(i2c, max31335_id);
689768

690769
static const struct of_device_id max31335_of_match[] = {
691-
{ .compatible = "adi,max31335" },
770+
{ .compatible = "adi,max31331", .data = &chip[ID_MAX31331] },
771+
{ .compatible = "adi,max31335", .data = &chip[ID_MAX31335] },
692772
{ }
693773
};
694774

@@ -705,5 +785,6 @@ static struct i2c_driver max31335_driver = {
705785
module_i2c_driver(max31335_driver);
706786

707787
MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
788+
MODULE_AUTHOR("Saket Kumar Purwar <Saket.Kumarpurwar@analog.com>");
708789
MODULE_DESCRIPTION("MAX31335 RTC driver");
709790
MODULE_LICENSE("GPL");

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