rtc: add driver for RX6110SA real time clock (68298c2d) · Commits · 戴 / test

drivers/rtc/Kconfig

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		@@ -743,6 +743,15 @@ config RTC_DRV_RX4581
		This driver can also be built as a module. If so the module
		will be called rtc-rx4581.

		config RTC_DRV_RX6110
		tristate "Epson RX-6110"
		select REGMAP_SPI
		help
		If you say yes here you will get support for the Epson RX-6610.

		This driver can also be built as a module. If so the module
		will be called rtc-rx6110.

		config RTC_DRV_MCP795
		tristate "Microchip MCP795"
		help

drivers/rtc/Makefile

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Original line number	Diff line number	Diff line
		@@ -127,6 +127,7 @@ obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o
		obj-$(CONFIG_RTC_DRV_RV3029C2) += rtc-rv3029c2.o
		obj-$(CONFIG_RTC_DRV_RV8803) += rtc-rv8803.o
		obj-$(CONFIG_RTC_DRV_RX4581) += rtc-rx4581.o
		obj-$(CONFIG_RTC_DRV_RX6110) += rtc-rx6110.o
		obj-$(CONFIG_RTC_DRV_RX8010) += rtc-rx8010.o
		obj-$(CONFIG_RTC_DRV_RX8025) += rtc-rx8025.o
		obj-$(CONFIG_RTC_DRV_RX8581) += rtc-rx8581.o

drivers/rtc/rtc-rx6110.c

0 → 100644

+402 −0

Original line number	Diff line number	Diff line
		/*
		* Driver for the Epson RTC module RX-6110 SA
		*
		* Copyright(C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
		* Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved.
		*
		* This driver software is distributed as is, without any warranty of any kind,
		* either express or implied as further specified in the GNU Public License.
		* This software may be used and distributed according to the terms of the GNU
		* Public License, version 2 as published by the Free Software Foundation.
		* See the file COPYING in the main directory of this archive for more details.
		*
		* You should have received a copy of the GNU General Public License along with
		* this program. If not, see <http://www.gnu.org/licenses/>.
		*/

		#include <linux/bcd.h>
		#include <linux/init.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/of_gpio.h>
		#include <linux/regmap.h>
		#include <linux/rtc.h>
		#include <linux/spi/spi.h>

		/* RX-6110 Register definitions */
		#define RX6110_REG_SEC 0x10
		#define RX6110_REG_MIN 0x11
		#define RX6110_REG_HOUR 0x12
		#define RX6110_REG_WDAY 0x13
		#define RX6110_REG_MDAY 0x14
		#define RX6110_REG_MONTH 0x15
		#define RX6110_REG_YEAR 0x16
		#define RX6110_REG_RES1 0x17
		#define RX6110_REG_ALMIN 0x18
		#define RX6110_REG_ALHOUR 0x19
		#define RX6110_REG_ALWDAY 0x1A
		#define RX6110_REG_TCOUNT0 0x1B
		#define RX6110_REG_TCOUNT1 0x1C
		#define RX6110_REG_EXT 0x1D
		#define RX6110_REG_FLAG 0x1E
		#define RX6110_REG_CTRL 0x1F
		#define RX6110_REG_USER0 0x20
		#define RX6110_REG_USER1 0x21
		#define RX6110_REG_USER2 0x22
		#define RX6110_REG_USER3 0x23
		#define RX6110_REG_USER4 0x24
		#define RX6110_REG_USER5 0x25
		#define RX6110_REG_USER6 0x26
		#define RX6110_REG_USER7 0x27
		#define RX6110_REG_USER8 0x28
		#define RX6110_REG_USER9 0x29
		#define RX6110_REG_USERA 0x2A
		#define RX6110_REG_USERB 0x2B
		#define RX6110_REG_USERC 0x2C
		#define RX6110_REG_USERD 0x2D
		#define RX6110_REG_USERE 0x2E
		#define RX6110_REG_USERF 0x2F
		#define RX6110_REG_RES2 0x30
		#define RX6110_REG_RES3 0x31
		#define RX6110_REG_IRQ 0x32

		#define RX6110_BIT_ALARM_EN BIT(7)

		/* Extension Register (1Dh) bit positions */
		#define RX6110_BIT_EXT_TSEL0 BIT(0)
		#define RX6110_BIT_EXT_TSEL1 BIT(1)
		#define RX6110_BIT_EXT_TSEL2 BIT(2)
		#define RX6110_BIT_EXT_WADA BIT(3)
		#define RX6110_BIT_EXT_TE BIT(4)
		#define RX6110_BIT_EXT_USEL BIT(5)
		#define RX6110_BIT_EXT_FSEL0 BIT(6)
		#define RX6110_BIT_EXT_FSEL1 BIT(7)

		/* Flag Register (1Eh) bit positions */
		#define RX6110_BIT_FLAG_VLF BIT(1)
		#define RX6110_BIT_FLAG_AF BIT(3)
		#define RX6110_BIT_FLAG_TF BIT(4)
		#define RX6110_BIT_FLAG_UF BIT(5)

		/* Control Register (1Fh) bit positions */
		#define RX6110_BIT_CTRL_TBKE BIT(0)
		#define RX6110_BIT_CTRL_TBKON BIT(1)
		#define RX6110_BIT_CTRL_TSTP BIT(2)
		#define RX6110_BIT_CTRL_AIE BIT(3)
		#define RX6110_BIT_CTRL_TIE BIT(4)
		#define RX6110_BIT_CTRL_UIE BIT(5)
		#define RX6110_BIT_CTRL_STOP BIT(6)
		#define RX6110_BIT_CTRL_TEST BIT(7)

		enum {
		RTC_SEC = 0,
		RTC_MIN,
		RTC_HOUR,
		RTC_WDAY,
		RTC_MDAY,
		RTC_MONTH,
		RTC_YEAR,
		RTC_NR_TIME
		};

		#define RX6110_DRIVER_NAME "rx6110"

		struct rx6110_data {
		struct rtc_device *rtc;
		struct regmap *regmap;
		};

		/**
		* rx6110_rtc_tm_to_data - convert rtc_time to native time encoding
		*
		* @tm: holds date and time
		* @data: holds the encoding in rx6110 native form
		*/
		static int rx6110_rtc_tm_to_data(struct rtc_time tm, u8 data)
		{
		pr_debug("%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year);

		/*
		* The year in the RTC is a value between 0 and 99.
		* Assume that this represents the current century
		* and disregard all other values.
		*/
		if (tm->tm_year < 100 \|\| tm->tm_year >= 200)
		return -EINVAL;

		data[RTC_SEC] = bin2bcd(tm->tm_sec);
		data[RTC_MIN] = bin2bcd(tm->tm_min);
		data[RTC_HOUR] = bin2bcd(tm->tm_hour);
		data[RTC_WDAY] = BIT(bin2bcd(tm->tm_wday));
		data[RTC_MDAY] = bin2bcd(tm->tm_mday);
		data[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
		data[RTC_YEAR] = bin2bcd(tm->tm_year % 100);

		return 0;
		}

		/**
		* rx6110_data_to_rtc_tm - convert native time encoding to rtc_time
		*
		* @data: holds the encoding in rx6110 native form
		* @tm: holds date and time
		*/
		static int rx6110_data_to_rtc_tm(u8 data, struct rtc_time tm)
		{
		tm->tm_sec = bcd2bin(data[RTC_SEC] & 0x7f);
		tm->tm_min = bcd2bin(data[RTC_MIN] & 0x7f);
		/* only 24-hour clock */
		tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);
		tm->tm_wday = ffs(data[RTC_WDAY] & 0x7f);
		tm->tm_mday = bcd2bin(data[RTC_MDAY] & 0x3f);
		tm->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1f) - 1;
		tm->tm_year = bcd2bin(data[RTC_YEAR]) + 100;

		pr_debug("%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year);

		/*
		* The year in the RTC is a value between 0 and 99.
		* Assume that this represents the current century
		* and disregard all other values.
		*/
		if (tm->tm_year < 100 \|\| tm->tm_year >= 200)
		return -EINVAL;

		return 0;
		}

		/**
		* rx6110_set_time - set the current time in the rx6110 registers
		*
		* @dev: the rtc device in use
		* @tm: holds date and time
		*
		* BUG: The HW assumes every year that is a multiple of 4 to be a leap
		* year. Next time this is wrong is 2100, which will not be a leap year
		*
		* Note: If STOP is not set/cleared, the clock will start when the seconds
		* register is written
		*
		*/
		static int rx6110_set_time(struct device dev, struct rtc_time tm)
		{
		struct rx6110_data *rx6110 = dev_get_drvdata(dev);
		u8 data[RTC_NR_TIME];
		int ret;

		ret = rx6110_rtc_tm_to_data(tm, data);
		if (ret < 0)
		return ret;

		/* set STOP bit before changing clock/calendar */
		ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,
		RX6110_BIT_CTRL_STOP, RX6110_BIT_CTRL_STOP);
		if (ret)
		return ret;

		ret = regmap_bulk_write(rx6110->regmap, RX6110_REG_SEC, data,
		RTC_NR_TIME);
		if (ret)
		return ret;

		/* The time in the RTC is valid. Be sure to have VLF cleared. */
		ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,
		RX6110_BIT_FLAG_VLF, 0);
		if (ret)
		return ret;

		/* clear STOP bit after changing clock/calendar */
		ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,
		RX6110_BIT_CTRL_STOP, 0);

		return ret;
		}

		/**
		* rx6110_get_time - get the current time from the rx6110 registers
		* @dev: the rtc device in use
		* @tm: holds date and time
		*/
		static int rx6110_get_time(struct device dev, struct rtc_time tm)
		{
		struct rx6110_data *rx6110 = dev_get_drvdata(dev);
		u8 data[RTC_NR_TIME];
		int flags;
		int ret;

		ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);
		if (ret)
		return -EINVAL;

		/* check for VLF Flag (set at power-on) */
		if ((flags & RX6110_BIT_FLAG_VLF)) {
		dev_warn(dev, "Voltage low, data is invalid.\n");
		return -EINVAL;
		}

		/* read registers to date */
		ret = regmap_bulk_read(rx6110->regmap, RX6110_REG_SEC, data,
		RTC_NR_TIME);
		if (ret)
		return ret;

		ret = rx6110_data_to_rtc_tm(data, tm);
		if (ret)
		return ret;

		dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year);

		return rtc_valid_tm(tm);
		}

		static const struct reg_sequence rx6110_default_regs[] = {
		{ RX6110_REG_RES1, 0xB8 },
		{ RX6110_REG_RES2, 0x00 },
		{ RX6110_REG_RES3, 0x10 },
		{ RX6110_REG_IRQ, 0x00 },
		{ RX6110_REG_ALMIN, 0x00 },
		{ RX6110_REG_ALHOUR, 0x00 },
		{ RX6110_REG_ALWDAY, 0x00 },
		};

		/**
		* rx6110_init - initialize the rx6110 registers
		*
		* @rx6110: pointer to the rx6110 struct in use
		*
		*/
		static int rx6110_init(struct rx6110_data *rx6110)
		{
		struct rtc_device *rtc = rx6110->rtc;
		int flags;
		int ret;

		ret = regmap_update_bits(rx6110->regmap, RX6110_REG_EXT,
		RX6110_BIT_EXT_TE, 0);
		if (ret)
		return ret;

		ret = regmap_register_patch(rx6110->regmap, rx6110_default_regs,
		ARRAY_SIZE(rx6110_default_regs));
		if (ret)
		return ret;

		ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);
		if (ret)
		return ret;

		/* check for VLF Flag (set at power-on) */
		if ((flags & RX6110_BIT_FLAG_VLF))
		dev_warn(&rtc->dev, "Voltage low, data loss detected.\n");

		/* check for Alarm Flag */
		if (flags & RX6110_BIT_FLAG_AF)
		dev_warn(&rtc->dev, "An alarm may have been missed.\n");

		/* check for Periodic Timer Flag */
		if (flags & RX6110_BIT_FLAG_TF)
		dev_warn(&rtc->dev, "Periodic timer was detected\n");

		/* check for Update Timer Flag */
		if (flags & RX6110_BIT_FLAG_UF)
		dev_warn(&rtc->dev, "Update timer was detected\n");

		/* clear all flags BUT VLF */
		ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,
		RX6110_BIT_FLAG_AF \|
		RX6110_BIT_FLAG_UF \|
		RX6110_BIT_FLAG_TF,
		0);

		return ret;
		}

		static struct rtc_class_ops rx6110_rtc_ops = {
		.read_time = rx6110_get_time,
		.set_time = rx6110_set_time,
		};

		static struct regmap_config regmap_spi_config = {
		.reg_bits = 8,
		.val_bits = 8,
		.max_register = RX6110_REG_IRQ,
		.read_flag_mask = 0x80,
		};

		/**
		* rx6110_probe - initialize rtc driver
		* @spi: pointer to spi device
		*/
		static int rx6110_probe(struct spi_device *spi)
		{
		struct rx6110_data *rx6110;
		int err;

		if ((spi->bits_per_word && spi->bits_per_word != 8) \|\|
		(spi->max_speed_hz > 2000000) \|\|
		(spi->mode != (SPI_CS_HIGH \| SPI_CPOL \| SPI_CPHA))) {
		dev_warn(&spi->dev, "SPI settings: bits_per_word: %d, max_speed_hz: %d, mode: %xh\n",
		spi->bits_per_word, spi->max_speed_hz, spi->mode);
		dev_warn(&spi->dev, "driving device in an unsupported mode");
		}

		rx6110 = devm_kzalloc(&spi->dev, sizeof(*rx6110), GFP_KERNEL);
		if (!rx6110)
		return -ENOMEM;

		rx6110->regmap = devm_regmap_init_spi(spi, &regmap_spi_config);
		if (IS_ERR(rx6110->regmap)) {
		dev_err(&spi->dev, "regmap init failed for rtc rx6110\n");
		return PTR_ERR(rx6110->regmap);
		}

		spi_set_drvdata(spi, rx6110);

		rx6110->rtc = devm_rtc_device_register(&spi->dev,
		RX6110_DRIVER_NAME,
		&rx6110_rtc_ops, THIS_MODULE);

		if (IS_ERR(rx6110->rtc))
		return PTR_ERR(rx6110->rtc);

		err = rx6110_init(rx6110);
		if (err)
		return err;

		rx6110->rtc->max_user_freq = 1;

		return 0;
		}

		static int rx6110_remove(struct spi_device *spi)
		{
		return 0;
		}

		static const struct spi_device_id rx6110_id[] = {
		{ "rx6110", 0 },
		{ }
		};
		MODULE_DEVICE_TABLE(spi, rx6110_id);

		static struct spi_driver rx6110_driver = {
		.driver = {
		.name = RX6110_DRIVER_NAME,
		.owner = THIS_MODULE,
		},
		.probe = rx6110_probe,
		.remove = rx6110_remove,
		.id_table = rx6110_id,
		};

		module_spi_driver(rx6110_driver);

		MODULE_AUTHOR("Val Krutov <val.krutov@erd.epson.com>");
		MODULE_DESCRIPTION("RX-6110 SA RTC driver");
		MODULE_LICENSE("GPL");

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