rtc: ds1390: Add trickle charger device tree binding (fa395fb8) · Commits · 戴 / test

Documentation/devicetree/bindings/rtc/dallas,ds1390.txt

0 → 100644

+18 −0

Original line number	Diff line number	Diff line
		* Dallas DS1390 SPI Serial Real-Time Clock

		Required properties:
		- compatible: Should contain "dallas,ds1390".
		- reg: SPI address for chip

		Optional properties:
		- trickle-resistor-ohms : Selected resistor for trickle charger
		Values usable for ds1390 are 250, 2000, 4000
		Should be given if trickle charger should be enabled
		- trickle-diode-disable : Do not use internal trickle charger diode
		Should be given if internal trickle charger diode should be disabled
		Example:
		ds1390: rtc@68 {
		compatible = "dallas,ds1390";
		trickle-resistor-ohms = <250>;
		reg = <0>;
		};

drivers/rtc/Kconfig

+2 −2

Original line number	Diff line number	Diff line
		@@ -666,8 +666,8 @@ config RTC_DRV_DS1390
		If you say yes here you get support for the
		Dallas/Maxim DS1390/93/94 chips.

		This driver only supports the RTC feature, and not other chip
		features such as alarms and trickle charging.
		This driver supports the RTC feature and trickle charging but not
		other chip features such as alarms.

		This driver can also be built as a module. If so, the module
		will be called rtc-ds1390.

drivers/rtc/rtc-ds1390.c

+63 −0

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@
		#include <linux/spi/spi.h>
		#include <linux/bcd.h>
		#include <linux/slab.h>
		#include <linux/of.h>

		#define DS1390_REG_100THS 0x00
		#define DS1390_REG_SECONDS 0x01
		@@ -40,11 +41,31 @@
		#define DS1390_REG_STATUS 0x0E
		#define DS1390_REG_TRICKLE 0x0F

		#define DS1390_TRICKLE_CHARGER_ENABLE 0xA0
		#define DS1390_TRICKLE_CHARGER_250_OHM 0x01
		#define DS1390_TRICKLE_CHARGER_2K_OHM 0x02
		#define DS1390_TRICKLE_CHARGER_4K_OHM 0x03
		#define DS1390_TRICKLE_CHARGER_NO_DIODE 0x04
		#define DS1390_TRICKLE_CHARGER_DIODE 0x08

		struct ds1390 {
		struct rtc_device *rtc;
		u8 txrx_buf[9]; /* cmd + 8 registers */
		};

		static void ds1390_set_reg(struct device *dev, unsigned char address,
		unsigned char data)
		{
		struct spi_device *spi = to_spi_device(dev);
		unsigned char buf[2];

		/* MSB must be '1' to write */
		buf[0] = address \| 0x80;
		buf[1] = data;

		spi_write(spi, buf, 2);
		}

		static int ds1390_get_reg(struct device *dev, unsigned char address,
		unsigned char *data)
		{
		@@ -67,6 +88,45 @@ static int ds1390_get_reg(struct device *dev, unsigned char address,
		return 0;
		}

		static void ds1390_trickle_of_init(struct spi_device *spi)
		{
		u32 ohms = 0;
		u8 value;

		if (of_property_read_u32(spi->dev.of_node, "trickle-resistor-ohms",
		&ohms))
		goto out;

		/* Enable charger */
		value = DS1390_TRICKLE_CHARGER_ENABLE;
		if (of_property_read_bool(spi->dev.of_node, "trickle-diode-disable"))
		value \|= DS1390_TRICKLE_CHARGER_NO_DIODE;
		else
		value \|= DS1390_TRICKLE_CHARGER_DIODE;

		/* Resistor select */
		switch (ohms) {
		case 250:
		value \|= DS1390_TRICKLE_CHARGER_250_OHM;
		break;
		case 2000:
		value \|= DS1390_TRICKLE_CHARGER_2K_OHM;
		break;
		case 4000:
		value \|= DS1390_TRICKLE_CHARGER_4K_OHM;
		break;
		default:
		dev_warn(&spi->dev,
		"Unsupported ohm value %02ux in dt\n", ohms);
		return;
		}

		ds1390_set_reg(&spi->dev, DS1390_REG_TRICKLE, value);

		out:
		return;
		}

		static int ds1390_read_time(struct device dev, struct rtc_time dt)
		{
		struct spi_device *spi = to_spi_device(dev);
		@@ -143,6 +203,9 @@ static int ds1390_probe(struct spi_device *spi)
		return res;
		}

		if (spi->dev.of_node)
		ds1390_trickle_of_init(spi);

		chip->rtc = devm_rtc_device_register(&spi->dev, "ds1390",
		&ds1390_rtc_ops, THIS_MODULE);
		if (IS_ERR(chip->rtc)) {

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