Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S943043AbcJSRmO (ORCPT ); Wed, 19 Oct 2016 13:42:14 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:34774 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S942726AbcJSRmN (ORCPT ); Wed, 19 Oct 2016 13:42:13 -0400 From: VENKAT PRASHANTH B U To: alexandre.belloni@free-electrons.com Cc: a.zummo@towertech.it, rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org, VENKAT PRASHANTH B U Subject: [PATCH v2] rtc: add support for rtc NXP pca21125 Date: Wed, 19 Oct 2016 10:41:04 -0700 Message-Id: <1476898864-7004-1-git-send-email-venkat.prashanth2498@gmail.com> X-Mailer: git-send-email 1.9.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7815 Lines: 292 This is a patch to add support for NXP rtc pca21125 Signed-off-by: Venkat Prashanth B U --- changelog v2: 1. used the registers defined in pca21125_set_time function 2. code cleanup in the function pca21125_read_time function 3. Write the address on the bus with pca21125_write_reg function 4. code clean up on pca21125_probe function 5. Add the alarm feature support feature in the driver code 6. fixed the indentation of entire file --- --- drivers/rtc/Kconfig | 9 ++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-pca21125.c | 234 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 244 insertions(+) diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index e215f50..29f40cb 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -739,6 +739,15 @@ config RTC_DRV_PCF2123 This driver can also be built as a module. If so, the module will be called rtc-pcf2123. +config RTC_DRV_PCA21125 + tristate "NXP PCA21125" + help + If you say yes here you get support for the NXP PCA21125 + RTC chip. + + This driver can also be built as a module. If so, the module + will be called rtc-pca21125. + config RTC_DRV_MCP795 tristate "Microchip MCP795" help diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 7cf7ad5..41a5807 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -106,6 +106,7 @@ obj-$(CONFIG_RTC_DRV_OMAP) += rtc-omap.o obj-$(CONFIG_RTC_DRV_OPAL) += rtc-opal.o obj-$(CONFIG_RTC_DRV_PALMAS) += rtc-palmas.o obj-$(CONFIG_RTC_DRV_PCAP) += rtc-pcap.o +obj-$(CONFIG_RTC_DRV_PCA21125) += rtc-pca21125.o obj-$(CONFIG_RTC_DRV_PCF2123) += rtc-pcf2123.o obj-$(CONFIG_RTC_DRV_PCF2127) += rtc-pcf2127.o obj-$(CONFIG_RTC_DRV_PCF50633) += rtc-pcf50633.o diff --git a/drivers/rtc/rtc-pca21125.c b/drivers/rtc/rtc-pca21125.c index e69de29..536cf50 100644 --- a/drivers/rtc/rtc-pca21125.c +++ b/drivers/rtc/rtc-pca21125.c @@ -0,0 +1,234 @@ + /* rtc-pca21125.c + * + * Driver for NXP PCA21125 CMOS, SPI Compatible + * Real Time Clock + * + * Author : Venkat Prashanth B U + * + * 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. + * + */ + + #include + #include + #include + #include + #include + #include + #include + #include + #include + #include + #include + #include + + /* Registers in pca21125 rtc */ + #define PCA21125_SECONDS_REG 0x02 + #define PCA21125_MINUTES_REG 0x03 + #define PCA21125_HOURS_REG 0x04 + #define PCA21125_DATE_REG 0x05 + #define PCA21125_DAY_REG 0x06 + #define PCA21125_MONTH_REG 0x07 + #define PCA21125_YEAR_REG 0x08 + #define PCA21125_CONTROL_REG 0x01 + #define PCA21125_STATUS_REG 0x00 + #define PCA21125_CLOCK_BURST 0x0D + + struct pca21125_priv { + + struct spi_device *spi; + struct rtc_device *rtc; + struct regmap *map; + struct mutex mutex; + unsigned int irqen; + int irq; + int alarm_sec; + int alarm_min; + int alarm_hour; + int alarm_mday; + }; + + static int + pca21125_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) + { + struct pca21125_priv *priv = dev_get_drvdata(dev); + int res = 0; + unsigned int stat; + + if (priv->irq <= 0) + return -EINVAL; + + mutex_lock(&priv->mutex); + + res = regmap_read(priv->map, PCA21125_STATUS_REG, &stat); + if (res) + goto out; + + alarm->enabled = !!(priv->irqen & RTC_AF); + + alarm->time.tm_sec = priv->alarm_sec < 0 ? 0 : priv->alarm_sec; + alarm->time.tm_min = priv->alarm_min < 0 ? 0 : priv->alarm_min; + alarm->time.tm_hour = priv->alarm_hour < 0 ? 0 : priv->alarm_hour; + alarm->time.tm_mday = priv->alarm_mday < 0 ? 0 : priv->alarm_mday; + +out: + mutex_unlock(&priv->mutex); + return res; + } + + static int + pca21125_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) + { + struct pca21125_priv *priv = dev_get_drvdata(dev); + int res = 0; + + if (priv->irq <= 0) + return -EINVAL; + + mutex_lock(&priv->mutex); + + priv->alarm_sec = alarm->time.tm_sec; + priv->alarm_min = alarm->time.tm_min; + priv->alarm_hour = alarm->time.tm_hour; + priv->alarm_mday = alarm->time.tm_mday; + + if (alarm->enabled) + priv->irqen |= RTC_AF; + + mutex_unlock(&priv->mutex); + + return res; + } + + static int + pca21125_read_reg(struct device *dev, unsigned char address, + unsigned char *data) + { + struct spi_device *spi = to_spi_device(dev); + unsigned char buf[2]; + + /* Set MSB to indicate read */ + *data = address | 0x80; + + return spi_write_then_read(spi, buf, 1, data, 1); + } + + static int + pca21125_write_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 '0' to write */ + buf[0] = address & 0x7F; + buf[1] = data; + + return spi_write_then_read(spi, buf, 2, NULL, 0); + } + + static int + pca21125_read_time(struct device *dev, struct rtc_time *dt) + { + struct spi_device *spi = to_spi_device(dev); + int err; + unsigned char buf[8]; + + buf[0] = 0xbf; /* Burst read */ + + err = spi_write_then_read(spi, buf, 1, buf, 8); + + if (err) + return err; + + /* The chip sends data in the order mentioned below*/ + + dt->tm_sec = bcd2bin(buf[0]); + dt->tm_min = bcd2bin(buf[1]); + dt->tm_hour = bcd2bin(buf[2]); + dt->tm_mday = bcd2bin(buf[3]); + dt->tm_mon = bcd2bin(buf[4]); + dt->tm_wday = bcd2bin(buf[5]); + dt->tm_year = bcd2bin(buf[6]); + + return rtc_valid_tm(dt); + } + + static int + pca21125_set_time(struct device *dev, struct rtc_time *dt) + { + struct spi_device *spi = to_spi_device(dev); + unsigned char buf[9]; + + dt->tm_year = dt->tm_year + 1900; + + if (dt->tm_year < 100 || dt->tm_year > 199) { + + dev_err(&spi->dev, "Year must be between 2000 and 2099. It's %d.\n", + dt->tm_year + 1900); + return -EINVAL; + } + + /* Remove write protection */ + pca21125_write_reg(dev, PCA21125_CONTROL_REG, 0); + + pca21125_write_reg(dev, PCA21125_SECONDS_REG, bin2bcd(dt->tm_sec)); + pca21125_write_reg(dev, PCA21125_MINUTES_REG, bin2bcd(dt->tm_min)); + pca21125_write_reg(dev, PCA21125_HOURS_REG, bin2bcd(dt->tm_hour)); + pca21125_write_reg(dev, PCA21125_DATE_REG, bin2bcd(dt->tm_mday)); + pca21125_write_reg(dev, PCA21125_MONTH_REG, bin2bcd(dt->tm_mon + 1)); + pca21125_write_reg(dev, PCA21125_DAY_REG, bin2bcd(dt->tm_wday)); + pca21125_write_reg(dev, PCA21125_YEAR_REG, bin2bcd(dt->tm_year % 100)); + + /* Write protect */ + pca21125_write_reg(dev, PCA21125_CONTROL_REG, 0x80); + + /* write the rtc settings */ + return spi_write_then_read(spi, buf, 9, NULL, 0); + } + + static const struct rtc_class_ops pca21125_rtc_ops = { + .read_time = pca21125_read_time, + .set_time = pca21125_set_time, + .read_alarm = pca21125_read_alarm, + .set_alarm = pca21125_set_alarm, + }; + + static int + pca21125_probe(struct spi_device *spi) + { + struct rtc_device *rtc; + unsigned char tmp; + int res; + + spi->mode = SPI_MODE_3; + spi->bits_per_word = 8; + spi_setup(spi); + + res = pca21125_read_reg(&spi->dev, PCA21125_SECONDS_REG, &tmp); + if (res != 0) + return res; + + rtc = devm_rtc_device_register(&spi->dev, "pca21125", + &pca21125_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + spi_set_drvdata(spi, rtc); + return 0; + } + + static struct spi_driver pca21125_driver = { + .driver = { + .name = "pca21125", + }, + .probe = pca21125_probe, + }; + + module_spi_driver(pca21125_driver); + + MODULE_DESCRIPTION("PCA21125 SPI RTC DRIVER"); + MODULE_AUTHOR("Venkat Prashanth B U "); + MODULE_LICENSE("GPL v2"); -- 1.9.2