[V2] rtc: add support for NXP PCF85363 real-time clock

Message ID 1507737390-27818-1-git-send-email-eric@nelint.com
State Superseded
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Series
  • [V2] rtc: add support for NXP PCF85363 real-time clock
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Commit Message

Eric Nelson Oct. 11, 2017, 3:56 p.m.
Note that alarms are not currently implemented.

64 bytes of nvmem is supported and exposed in
sysfs (# is the instance number, starting with 0):

	/sys/bus/nvmem/devices/pcf85363-#/nvmem

Signed-off-by: Eric Nelson <eric@nelint.com>
---
V2 addresses a couple of issues highlighted by Fabio Estevam
    1. Kconfig updated to select REGMAP_I2C
    2. Switch to of_device_id from i2c_device_id for driver matching

 Documentation/devicetree/bindings/rtc/pcf85363.txt |  16 ++
 drivers/rtc/Kconfig                                |  13 ++
 drivers/rtc/Makefile                               |   1 +
 drivers/rtc/rtc-pcf85363.c                         | 221 +++++++++++++++++++++
 4 files changed, 251 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/pcf85363.txt
 create mode 100644 drivers/rtc/rtc-pcf85363.c

Comments

Fabio Estevam Oct. 12, 2017, 9:55 p.m. | #1
On Wed, Oct 11, 2017 at 12:56 PM, Eric Nelson <eric@nelint.com> wrote:
> Note that alarms are not currently implemented.
>
> 64 bytes of nvmem is supported and exposed in
> sysfs (# is the instance number, starting with 0):
>
>         /sys/bus/nvmem/devices/pcf85363-#/nvmem
>
> Signed-off-by: Eric Nelson <eric@nelint.com>

Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Rob Herring Oct. 17, 2017, 8:06 p.m. | #2
On Wed, Oct 11, 2017 at 08:56:30AM -0700, Eric Nelson wrote:
> Note that alarms are not currently implemented.
> 
> 64 bytes of nvmem is supported and exposed in
> sysfs (# is the instance number, starting with 0):
> 
> 	/sys/bus/nvmem/devices/pcf85363-#/nvmem
> 
> Signed-off-by: Eric Nelson <eric@nelint.com>
> ---
> V2 addresses a couple of issues highlighted by Fabio Estevam
>     1. Kconfig updated to select REGMAP_I2C
>     2. Switch to of_device_id from i2c_device_id for driver matching
> 
>  Documentation/devicetree/bindings/rtc/pcf85363.txt |  16 ++
>  drivers/rtc/Kconfig                                |  13 ++
>  drivers/rtc/Makefile                               |   1 +
>  drivers/rtc/rtc-pcf85363.c                         | 221 +++++++++++++++++++++
>  4 files changed, 251 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/rtc/pcf85363.txt
>  create mode 100644 drivers/rtc/rtc-pcf85363.c
> 
> diff --git a/Documentation/devicetree/bindings/rtc/pcf85363.txt b/Documentation/devicetree/bindings/rtc/pcf85363.txt
> new file mode 100644
> index 0000000..5fddb9f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/pcf85363.txt
> @@ -0,0 +1,16 @@
> +NXP PCF85363 Real Time Clock
> +============================
> +
> +Required properties:
> +- compatible: Should contain "nxp,pcf85363".
> +- reg: I2C address for chip.
> +
> +Example:
> +
> +pcf85363: pcf85363@51 {
> +	compatible = "nxp,pcf85363";
> +	reg = <0x51>;
> +};
> +
> +Note that alarms are not yet supported, so a specifier for
> +"interrupts" will be ignored.

Irrelevant to the binding. That's a driver feature (or lack of). If the 
device has an interrupt line, you should document it. It can be optional 
though.

Rob
Eric Nelson Oct. 17, 2017, 10:24 p.m. | #3
Hi Rob,

On 10/17/2017 01:06 PM, Rob Herring wrote:
> On Wed, Oct 11, 2017 at 08:56:30AM -0700, Eric Nelson wrote:
>> Note that alarms are not currently implemented.
>>
>> 64 bytes of nvmem is supported and exposed in
>> sysfs (# is the instance number, starting with 0):
>>
>> 	/sys/bus/nvmem/devices/pcf85363-#/nvmem
>>
>> Signed-off-by: Eric Nelson <eric@nelint.com>
>> ---
>> V2 addresses a couple of issues highlighted by Fabio Estevam
>>      1. Kconfig updated to select REGMAP_I2C
>>      2. Switch to of_device_id from i2c_device_id for driver matching
>>
>>   Documentation/devicetree/bindings/rtc/pcf85363.txt |  16 ++
>>   drivers/rtc/Kconfig                                |  13 ++
>>   drivers/rtc/Makefile                               |   1 +
>>   drivers/rtc/rtc-pcf85363.c                         | 221 +++++++++++++++++++++
>>   4 files changed, 251 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/rtc/pcf85363.txt
>>   create mode 100644 drivers/rtc/rtc-pcf85363.c
>>
>> diff --git a/Documentation/devicetree/bindings/rtc/pcf85363.txt b/Documentation/devicetree/bindings/rtc/pcf85363.txt
>> new file mode 100644
>> index 0000000..5fddb9f
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/rtc/pcf85363.txt
>> @@ -0,0 +1,16 @@
>> +NXP PCF85363 Real Time Clock
>> +============================
>> +
>> +Required properties:
>> +- compatible: Should contain "nxp,pcf85363".
>> +- reg: I2C address for chip.
>> +
>> +Example:
>> +
>> +pcf85363: pcf85363@51 {
>> +	compatible = "nxp,pcf85363";
>> +	reg = <0x51>;
>> +};
>> +
>> +Note that alarms are not yet supported, so a specifier for
>> +"interrupts" will be ignored.
> 
> Irrelevant to the binding. That's a driver feature (or lack of). If the
> device has an interrupt line, you should document it. It can be optional
> though.
> 

That's what I was attempting do do in an awkward way.

Since the driver doesn't support interrupts or alarms at the moment,
I'll remove this note.

The chip does have an interrupt pin, but the board I have doesn't
have it connected.

Regards,


Eric
Rob Herring Oct. 19, 2017, 9:24 p.m. | #4
On Tue, Oct 17, 2017 at 5:24 PM, Eric Nelson <eric@nelint.com> wrote:
> Hi Rob,
>
>
> On 10/17/2017 01:06 PM, Rob Herring wrote:
>>
>> On Wed, Oct 11, 2017 at 08:56:30AM -0700, Eric Nelson wrote:
>>>
>>> Note that alarms are not currently implemented.
>>>
>>> 64 bytes of nvmem is supported and exposed in
>>> sysfs (# is the instance number, starting with 0):
>>>
>>>         /sys/bus/nvmem/devices/pcf85363-#/nvmem
>>>
>>> Signed-off-by: Eric Nelson <eric@nelint.com>
>>> ---
>>> V2 addresses a couple of issues highlighted by Fabio Estevam
>>>      1. Kconfig updated to select REGMAP_I2C
>>>      2. Switch to of_device_id from i2c_device_id for driver matching
>>>
>>>   Documentation/devicetree/bindings/rtc/pcf85363.txt |  16 ++
>>>   drivers/rtc/Kconfig                                |  13 ++
>>>   drivers/rtc/Makefile                               |   1 +
>>>   drivers/rtc/rtc-pcf85363.c                         | 221
>>> +++++++++++++++++++++
>>>   4 files changed, 251 insertions(+)
>>>   create mode 100644 Documentation/devicetree/bindings/rtc/pcf85363.txt
>>>   create mode 100644 drivers/rtc/rtc-pcf85363.c
>>>
>>> diff --git a/Documentation/devicetree/bindings/rtc/pcf85363.txt
>>> b/Documentation/devicetree/bindings/rtc/pcf85363.txt
>>> new file mode 100644
>>> index 0000000..5fddb9f
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/rtc/pcf85363.txt
>>> @@ -0,0 +1,16 @@
>>> +NXP PCF85363 Real Time Clock
>>> +============================
>>> +
>>> +Required properties:
>>> +- compatible: Should contain "nxp,pcf85363".
>>> +- reg: I2C address for chip.
>>> +
>>> +Example:
>>> +
>>> +pcf85363: pcf85363@51 {
>>> +       compatible = "nxp,pcf85363";
>>> +       reg = <0x51>;
>>> +};
>>> +
>>> +Note that alarms are not yet supported, so a specifier for
>>> +"interrupts" will be ignored.
>>
>>
>> Irrelevant to the binding. That's a driver feature (or lack of). If the
>> device has an interrupt line, you should document it. It can be optional
>> though.
>>
>
> That's what I was attempting do do in an awkward way.
>
> Since the driver doesn't support interrupts or alarms at the moment,
> I'll remove this note.
>
> The chip does have an interrupt pin, but the board I have doesn't
> have it connected.

Then just document "interrupts" as optional.

Rob

Patch

diff --git a/Documentation/devicetree/bindings/rtc/pcf85363.txt b/Documentation/devicetree/bindings/rtc/pcf85363.txt
new file mode 100644
index 0000000..5fddb9f
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/pcf85363.txt
@@ -0,0 +1,16 @@ 
+NXP PCF85363 Real Time Clock
+============================
+
+Required properties:
+- compatible: Should contain "nxp,pcf85363".
+- reg: I2C address for chip.
+
+Example:
+
+pcf85363: pcf85363@51 {
+	compatible = "nxp,pcf85363";
+	reg = <0x51>;
+};
+
+Note that alarms are not yet supported, so a specifier for
+"interrupts" will be ignored.
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index e0e58f3..15306ed 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -433,6 +433,19 @@  config RTC_DRV_PCF85063
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-pcf85063.
 
+config RTC_DRV_PCF85363
+	tristate "NXP PCF85363"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for the PCF85363 RTC chip.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-pcf85363.
+
+	  The nvmem interface will be named pcf85363-#, where # is the
+	  zero-based instance number.
+
 config RTC_DRV_PCF8563
 	tristate "Philips PCF8563/Epson RTC8564"
 	help
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 7230014..934a9dd 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -113,6 +113,7 @@  obj-$(CONFIG_RTC_DRV_PCF2123)	+= rtc-pcf2123.o
 obj-$(CONFIG_RTC_DRV_PCF2127)	+= rtc-pcf2127.o
 obj-$(CONFIG_RTC_DRV_PCF50633)	+= rtc-pcf50633.o
 obj-$(CONFIG_RTC_DRV_PCF85063)	+= rtc-pcf85063.o
+obj-$(CONFIG_RTC_DRV_PCF85363)	+= rtc-pcf85363.o
 obj-$(CONFIG_RTC_DRV_PCF8523)	+= rtc-pcf8523.o
 obj-$(CONFIG_RTC_DRV_PCF8563)	+= rtc-pcf8563.o
 obj-$(CONFIG_RTC_DRV_PCF8583)	+= rtc-pcf8583.o
diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
new file mode 100644
index 0000000..cf1e70c
--- /dev/null
+++ b/drivers/rtc/rtc-pcf85363.c
@@ -0,0 +1,221 @@ 
+/*
+ * drivers/rtc/rtc-pcf85363.c
+ *
+ * Driver for NXP PCF85363 real-time clock.
+ *
+ * Copyright (C) 2017 Eric Nelson
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Based loosely on rtc-8583 by Russell King, Wolfram Sang and Juergen Beisert
+ */
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/bcd.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+/*
+ * Date/Time registers
+ */
+#define DT_100THS	0x00
+#define DT_SECS		0x01
+#define DT_MINUTES	0x02
+#define DT_HOURS	0x03
+#define DT_DAYS		0x04
+#define DT_WEEKDAYS	0x05
+#define DT_MONTHS	0x06
+#define DT_YEARS	0x07
+
+/*
+ * Alarm registers
+ */
+#define DT_SECOND_ALM1	0x08
+#define DT_MINUTE_ALM1	0x09
+#define DT_HOUR_ALM1	0x0a
+#define DT_DAY_ALM1	0x0b
+#define DT_MONTH_ALM1	0x0c
+#define DT_MINUTE_ALM2	0x0d
+#define DT_HOUR_ALM2	0x0e
+#define DT_WEEKDAY_ALM2	0x0f
+#define DT_ALARM_EN	0x10
+
+/*
+ * Time stamp registers
+ */
+#define DT_TIMESTAMP1	0x11
+#define DT_TIMESTAMP2	0x17
+#define DT_TIMESTAMP3	0x1d
+#define DT_TS_MODE	0x23
+
+/*
+ * control registers
+ */
+#define CTRL_OFFSET	0x24
+#define CTRL_OSCILLATOR	0x25
+#define CTRL_BATTERY	0x26
+#define CTRL_PIN_IO	0x27
+#define CTRL_FUNCTION	0x28
+#define CTRL_INTA_EN	0x29
+#define CTRL_INTB_EN	0x2a
+#define CTRL_FLAGS	0x2b
+#define CTRL_RAMBYTE	0x2c
+#define CTRL_WDOG	0x2d
+#define CTRL_STOP_EN	0x2e
+#define CTRL_RESETS	0x2f
+#define CTRL_RAM	0x40
+
+#define NVRAM_SIZE	0x40
+
+static struct i2c_driver pcf85363_driver;
+
+struct pcf85363 {
+	struct device		*dev;
+	struct rtc_device	*rtc;
+	struct nvmem_config	nvmem_cfg;
+	struct regmap		*regmap;
+};
+
+static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
+	unsigned char buf[DT_YEARS + 1];
+	int ret, len = sizeof(buf);
+
+	/* read the RTC date and time registers all at once */
+	ret = regmap_bulk_read(pcf85363->regmap, DT_100THS, buf, len);
+	if (ret) {
+		dev_err(dev, "%s: error %d\n", __func__, ret);
+		return ret;
+	}
+
+	tm->tm_year = bcd2bin(buf[DT_YEARS]);
+	/* adjust for 1900 base of rtc_time */
+	tm->tm_year += 100;
+
+	tm->tm_wday = buf[DT_WEEKDAYS] & 7;
+	buf[DT_SECS] &= 0x7F;
+	tm->tm_sec = bcd2bin(buf[DT_SECS]);
+	buf[DT_MINUTES] &= 0x7F;
+	tm->tm_min = bcd2bin(buf[DT_MINUTES]);
+	tm->tm_hour = bcd2bin(buf[DT_HOURS]);
+	tm->tm_mday = bcd2bin(buf[DT_DAYS]);
+	tm->tm_mon = bcd2bin(buf[DT_MONTHS]) - 1;
+
+	return 0;
+}
+
+static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
+	unsigned char buf[DT_YEARS + 1];
+	int len = sizeof(buf);
+
+	buf[DT_100THS] = 0;
+	buf[DT_SECS] = bin2bcd(tm->tm_sec);
+	buf[DT_MINUTES] = bin2bcd(tm->tm_min);
+	buf[DT_HOURS] = bin2bcd(tm->tm_hour);
+	buf[DT_DAYS] = bin2bcd(tm->tm_mday);
+	buf[DT_WEEKDAYS] = tm->tm_wday;
+	buf[DT_MONTHS] = bin2bcd(tm->tm_mon + 1);
+	buf[DT_YEARS] = bin2bcd(tm->tm_year % 100);
+
+	return regmap_bulk_write(pcf85363->regmap, DT_100THS,
+				 buf, len);
+}
+
+static const struct rtc_class_ops rtc_ops = {
+	.read_time	= pcf85363_rtc_read_time,
+	.set_time	= pcf85363_rtc_set_time,
+};
+
+static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val,
+			       size_t bytes)
+{
+	struct pcf85363 *pcf85363 = priv;
+
+	return regmap_bulk_read(pcf85363->regmap, CTRL_RAM + offset,
+				val, bytes);
+}
+
+static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val,
+				size_t bytes)
+{
+	struct pcf85363 *pcf85363 = priv;
+
+	return regmap_bulk_write(pcf85363->regmap, CTRL_RAM + offset,
+				 val, bytes);
+}
+
+static const struct regmap_config regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int pcf85363_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	struct pcf85363 *pcf85363;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -ENODEV;
+
+	pcf85363 = devm_kzalloc(&client->dev, sizeof(struct pcf85363),
+				GFP_KERNEL);
+	if (!pcf85363)
+		return -ENOMEM;
+
+	pcf85363->regmap = devm_regmap_init_i2c(client, &regmap_config);
+	if (IS_ERR(pcf85363->regmap)) {
+		dev_err(&client->dev, "regmap allocation failed\n");
+		return PTR_ERR(pcf85363->regmap);
+	}
+
+	pcf85363->dev = &client->dev;
+	i2c_set_clientdata(client, pcf85363);
+
+	pcf85363->rtc = devm_rtc_allocate_device(pcf85363->dev);
+	if (IS_ERR(pcf85363->rtc))
+		return PTR_ERR(pcf85363->rtc);
+
+	pcf85363->nvmem_cfg.name = "pcf85363-";
+	pcf85363->nvmem_cfg.word_size = 1;
+	pcf85363->nvmem_cfg.stride = 1;
+	pcf85363->nvmem_cfg.size = NVRAM_SIZE;
+	pcf85363->nvmem_cfg.reg_read = pcf85363_nvram_read;
+	pcf85363->nvmem_cfg.reg_write = pcf85363_nvram_write;
+	pcf85363->nvmem_cfg.priv = pcf85363;
+	pcf85363->rtc->nvmem_config = &pcf85363->nvmem_cfg;
+	pcf85363->rtc->nvram_old_abi = true;
+	pcf85363->rtc->ops = &rtc_ops;
+
+	return rtc_register_device(pcf85363->rtc);
+}
+
+static const struct of_device_id dev_ids[] = {
+	{ .compatible = "nxp,pcf85363" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, dev_ids);
+
+static struct i2c_driver pcf85363_driver = {
+	.driver	= {
+		.name	= "pcf85363",
+		.of_match_table = of_match_ptr(dev_ids),
+	},
+	.probe	= pcf85363_probe,
+};
+
+module_i2c_driver(pcf85363_driver);
+
+MODULE_AUTHOR("Eric Nelson");
+MODULE_DESCRIPTION("pcf85363 I2C RTC driver");
+MODULE_LICENSE("GPL");