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linux/drivers/rtc/rtc-ds1343.c
Uwe Kleine-König a0386bba70
spi: make remove callback a void function 
The value returned by an spi driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Claudius Heine <ch@denx.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-09 13:00:45 +00:00

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// SPDX-License-Identifier: GPL-2.0-only
/* rtc-ds1343.c
*
* Driver for Dallas Semiconductor DS1343 Low Current, SPI Compatible
* Real Time Clock
*
* Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
* Ankur Srivastava <sankurece@gmail.com> : DS1343 Nvram Support
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/pm.h>
#include <linux/pm_wakeirq.h>
#include <linux/slab.h>
#define DALLAS_MAXIM_DS1343 0
#define DALLAS_MAXIM_DS1344 1
/* RTC DS1343 Registers */
#define DS1343_SECONDS_REG 0x00
#define DS1343_MINUTES_REG 0x01
#define DS1343_HOURS_REG 0x02
#define DS1343_DAY_REG 0x03
#define DS1343_DATE_REG 0x04
#define DS1343_MONTH_REG 0x05
#define DS1343_YEAR_REG 0x06
#define DS1343_ALM0_SEC_REG 0x07
#define DS1343_ALM0_MIN_REG 0x08
#define DS1343_ALM0_HOUR_REG 0x09
#define DS1343_ALM0_DAY_REG 0x0A
#define DS1343_ALM1_SEC_REG 0x0B
#define DS1343_ALM1_MIN_REG 0x0C
#define DS1343_ALM1_HOUR_REG 0x0D
#define DS1343_ALM1_DAY_REG 0x0E
#define DS1343_CONTROL_REG 0x0F
#define DS1343_STATUS_REG 0x10
#define DS1343_TRICKLE_REG 0x11
#define DS1343_NVRAM 0x20
#define DS1343_NVRAM_LEN 96
/* DS1343 Control Registers bits */
#define DS1343_EOSC 0x80
#define DS1343_DOSF 0x20
#define DS1343_EGFIL 0x10
#define DS1343_SQW 0x08
#define DS1343_INTCN 0x04
#define DS1343_A1IE 0x02
#define DS1343_A0IE 0x01
/* DS1343 Status Registers bits */
#define DS1343_OSF 0x80
#define DS1343_IRQF1 0x02
#define DS1343_IRQF0 0x01
/* DS1343 Trickle Charger Registers bits */
#define DS1343_TRICKLE_MAGIC 0xa0
#define DS1343_TRICKLE_DS1 0x08
#define DS1343_TRICKLE_1K 0x01
#define DS1343_TRICKLE_2K 0x02
#define DS1343_TRICKLE_4K 0x03
static const struct spi_device_id ds1343_id[] = {
{ "ds1343", DALLAS_MAXIM_DS1343 },
{ "ds1344", DALLAS_MAXIM_DS1344 },
{ }
};
MODULE_DEVICE_TABLE(spi, ds1343_id);
struct ds1343_priv {
struct rtc_device *rtc;
struct regmap *map;
int irq;
};
static ssize_t ds1343_show_glitchfilter(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ds1343_priv *priv = dev_get_drvdata(dev->parent);
int glitch_filt_status, data;
int res;
res = regmap_read(priv->map, DS1343_CONTROL_REG, &data);
if (res)
return res;
glitch_filt_status = !!(data & DS1343_EGFIL);
if (glitch_filt_status)
return sprintf(buf, "enabled\n");
else
return sprintf(buf, "disabled\n");
}
static ssize_t ds1343_store_glitchfilter(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct ds1343_priv *priv = dev_get_drvdata(dev->parent);
int data = 0;
int res;
if (strncmp(buf, "enabled", 7) == 0)
data = DS1343_EGFIL;
else if (strncmp(buf, "disabled", 8))
return -EINVAL;
res = regmap_update_bits(priv->map, DS1343_CONTROL_REG,
DS1343_EGFIL, data);
if (res)
return res;
return count;
}
static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter,
ds1343_store_glitchfilter);
static int ds1343_nvram_write(void *priv, unsigned int off, void *val,
size_t bytes)
{
struct ds1343_priv *ds1343 = priv;
return regmap_bulk_write(ds1343->map, DS1343_NVRAM + off, val, bytes);
}
static int ds1343_nvram_read(void *priv, unsigned int off, void *val,
size_t bytes)
{
struct ds1343_priv *ds1343 = priv;
return regmap_bulk_read(ds1343->map, DS1343_NVRAM + off, val, bytes);
}
static ssize_t ds1343_show_tricklecharger(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ds1343_priv *priv = dev_get_drvdata(dev->parent);
int res, data;
char *diodes = "disabled", *resistors = " ";
res = regmap_read(priv->map, DS1343_TRICKLE_REG, &data);
if (res)
return res;
if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) {
switch (data & 0x0c) {
case DS1343_TRICKLE_DS1:
diodes = "one diode,";
break;
default:
diodes = "no diode,";
break;
}
switch (data & 0x03) {
case DS1343_TRICKLE_1K:
resistors = "1k Ohm";
break;
case DS1343_TRICKLE_2K:
resistors = "2k Ohm";
break;
case DS1343_TRICKLE_4K:
resistors = "4k Ohm";
break;
default:
diodes = "disabled";
break;
}
}
return sprintf(buf, "%s %s\n", diodes, resistors);
}
static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL);
static struct attribute *ds1343_attrs[] = {
&dev_attr_glitch_filter.attr,
&dev_attr_trickle_charger.attr,
NULL
};
static const struct attribute_group ds1343_attr_group = {
.attrs = ds1343_attrs,
};
static int ds1343_read_time(struct device *dev, struct rtc_time *dt)
{
struct ds1343_priv *priv = dev_get_drvdata(dev);
unsigned char buf[7];
int res;
res = regmap_bulk_read(priv->map, DS1343_SECONDS_REG, buf, 7);
if (res)
return res;
dt->tm_sec = bcd2bin(buf[0]);
dt->tm_min = bcd2bin(buf[1]);
dt->tm_hour = bcd2bin(buf[2] & 0x3F);
dt->tm_wday = bcd2bin(buf[3]) - 1;
dt->tm_mday = bcd2bin(buf[4]);
dt->tm_mon = bcd2bin(buf[5] & 0x1F) - 1;
dt->tm_year = bcd2bin(buf[6]) + 100; /* year offset from 1900 */
return 0;
}
static int ds1343_set_time(struct device *dev, struct rtc_time *dt)
{
struct ds1343_priv *priv = dev_get_drvdata(dev);
u8 buf[7];
buf[0] = bin2bcd(dt->tm_sec);
buf[1] = bin2bcd(dt->tm_min);
buf[2] = bin2bcd(dt->tm_hour) & 0x3F;
buf[3] = bin2bcd(dt->tm_wday + 1);
buf[4] = bin2bcd(dt->tm_mday);
buf[5] = bin2bcd(dt->tm_mon + 1);
buf[6] = bin2bcd(dt->tm_year - 100);
return regmap_bulk_write(priv->map, DS1343_SECONDS_REG,
buf, sizeof(buf));
}
static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct ds1343_priv *priv = dev_get_drvdata(dev);
unsigned char buf[4];
unsigned int val;
int res;
if (priv->irq <= 0)
return -EINVAL;
res = regmap_read(priv->map, DS1343_STATUS_REG, &val);
if (res)
return res;
alarm->pending = !!(val & DS1343_IRQF0);
res = regmap_read(priv->map, DS1343_CONTROL_REG, &val);
if (res)
return res;
alarm->enabled = !!(val & DS1343_A0IE);
res = regmap_bulk_read(priv->map, DS1343_ALM0_SEC_REG, buf, 4);
if (res)
return res;
alarm->time.tm_sec = bcd2bin(buf[0]) & 0x7f;
alarm->time.tm_min = bcd2bin(buf[1]) & 0x7f;
alarm->time.tm_hour = bcd2bin(buf[2]) & 0x3f;
alarm->time.tm_mday = bcd2bin(buf[3]) & 0x3f;
return 0;
}
static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct ds1343_priv *priv = dev_get_drvdata(dev);
unsigned char buf[4];
int res = 0;
if (priv->irq <= 0)
return -EINVAL;
res = regmap_update_bits(priv->map, DS1343_CONTROL_REG, DS1343_A0IE, 0);
if (res)
return res;
buf[0] = bin2bcd(alarm->time.tm_sec);
buf[1] = bin2bcd(alarm->time.tm_min);
buf[2] = bin2bcd(alarm->time.tm_hour);
buf[3] = bin2bcd(alarm->time.tm_mday);
res = regmap_bulk_write(priv->map, DS1343_ALM0_SEC_REG, buf, 4);
if (res)
return res;
if (alarm->enabled)
res = regmap_update_bits(priv->map, DS1343_CONTROL_REG,
DS1343_A0IE, DS1343_A0IE);
return res;
}
static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct ds1343_priv *priv = dev_get_drvdata(dev);
if (priv->irq <= 0)
return -EINVAL;
return regmap_update_bits(priv->map, DS1343_CONTROL_REG,
DS1343_A0IE, enabled ? DS1343_A0IE : 0);
}
static irqreturn_t ds1343_thread(int irq, void *dev_id)
{
struct ds1343_priv *priv = dev_id;
unsigned int stat;
int res = 0;
rtc_lock(priv->rtc);
res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
if (res)
goto out;
if (stat & DS1343_IRQF0) {
stat &= ~DS1343_IRQF0;
regmap_write(priv->map, DS1343_STATUS_REG, stat);
rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF);
regmap_update_bits(priv->map, DS1343_CONTROL_REG,
DS1343_A0IE, 0);
}
out:
rtc_unlock(priv->rtc);
return IRQ_HANDLED;
}
static const struct rtc_class_ops ds1343_rtc_ops = {
.read_time = ds1343_read_time,
.set_time = ds1343_set_time,
.read_alarm = ds1343_read_alarm,
.set_alarm = ds1343_set_alarm,
.alarm_irq_enable = ds1343_alarm_irq_enable,
};
static int ds1343_probe(struct spi_device *spi)
{
struct ds1343_priv *priv;
struct regmap_config config = { .reg_bits = 8, .val_bits = 8,
.write_flag_mask = 0x80, };
unsigned int data;
int res;
struct nvmem_config nvmem_cfg = {
.name = "ds1343-",
.word_size = 1,
.stride = 1,
.size = DS1343_NVRAM_LEN,
.reg_read = ds1343_nvram_read,
.reg_write = ds1343_nvram_write,
};
priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
/* RTC DS1347 works in spi mode 3 and
* its chip select is active high. Active high should be defined as
* "inverse polarity" as GPIO-based chip selects can be logically
* active high but inverted by the GPIO library.
*/
spi->mode |= SPI_MODE_3;
spi->mode ^= SPI_CS_HIGH;
spi->bits_per_word = 8;
res = spi_setup(spi);
if (res)
return res;
spi_set_drvdata(spi, priv);
priv->map = devm_regmap_init_spi(spi, &config);
if (IS_ERR(priv->map)) {
dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n");
return PTR_ERR(priv->map);
}
res = regmap_read(priv->map, DS1343_SECONDS_REG, &data);
if (res)
return res;
regmap_read(priv->map, DS1343_CONTROL_REG, &data);
data |= DS1343_INTCN;
data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE);
regmap_write(priv->map, DS1343_CONTROL_REG, data);
regmap_read(priv->map, DS1343_STATUS_REG, &data);
data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0);
regmap_write(priv->map, DS1343_STATUS_REG, data);
priv->rtc = devm_rtc_allocate_device(&spi->dev);
if (IS_ERR(priv->rtc))
return PTR_ERR(priv->rtc);
priv->rtc->ops = &ds1343_rtc_ops;
priv->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
priv->rtc->range_max = RTC_TIMESTAMP_END_2099;
res = rtc_add_group(priv->rtc, &ds1343_attr_group);
if (res)
dev_err(&spi->dev,
"unable to create sysfs entries for rtc ds1343\n");
res = devm_rtc_register_device(priv->rtc);
if (res)
return res;
nvmem_cfg.priv = priv;
devm_rtc_nvmem_register(priv->rtc, &nvmem_cfg);
priv->irq = spi->irq;
if (priv->irq >= 0) {
res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
ds1343_thread, IRQF_ONESHOT,
"ds1343", priv);
if (res) {
priv->irq = -1;
dev_err(&spi->dev,
"unable to request irq for rtc ds1343\n");
} else {
device_init_wakeup(&spi->dev, true);
dev_pm_set_wake_irq(&spi->dev, spi->irq);
}
}
return 0;
}
static void ds1343_remove(struct spi_device *spi)
{
dev_pm_clear_wake_irq(&spi->dev);
}
#ifdef CONFIG_PM_SLEEP
static int ds1343_suspend(struct device *dev)
{
struct spi_device *spi = to_spi_device(dev);
if (spi->irq >= 0 && device_may_wakeup(dev))
enable_irq_wake(spi->irq);
return 0;
}
static int ds1343_resume(struct device *dev)
{
struct spi_device *spi = to_spi_device(dev);
if (spi->irq >= 0 && device_may_wakeup(dev))
disable_irq_wake(spi->irq);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume);
static struct spi_driver ds1343_driver = {
.driver = {
.name = "ds1343",
.pm = &ds1343_pm,
},
.probe = ds1343_probe,
.remove = ds1343_remove,
.id_table = ds1343_id,
};
module_spi_driver(ds1343_driver);
MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>,"
"Ankur Srivastava <sankurece@gmail.com>");
MODULE_LICENSE("GPL v2");
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