Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933313AbcJROsO (ORCPT ); Tue, 18 Oct 2016 10:48:14 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:36841 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751598AbcJROsG (ORCPT ); Tue, 18 Oct 2016 10:48:06 -0400 From: VENKAT PRASHANTH B U To: alexandre.belloni@free-electrons.com Cc: linux-kernel@vger.kernel.org, a.zummo@towertech.it, VENKAT PRASHANTH B U Subject: [PATCH] rtc: add support for rtc NXP pca21125 Date: Tue, 18 Oct 2016 07:47:24 -0700 Message-Id: <1476802044-6016-1-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: 6260 Lines: 217 This is the patch to add support for NXP rtc pca21125 Signed-off-by: Venkat Prashanth B U --- --- drivers/rtc/Kconfig | 12 ++++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-pca21125.c | 164 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 177 insertions(+) diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index e215f50..df10e0e 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -686,6 +686,18 @@ config RTC_DRV_MAX6916 This driver can also be built as a module. If so, the module will be called rtc-max6916. +config RTC_DRV_PCA21125 + tristate "NXP PCA21125" + help + If you say yes here you will get support for the + NXP PCA21125 SPI RTC chip. + + This driver only supports the RTC feature, and not other chip + features such as alarms. + + This driver can also be built as a module. If so, the module + will be called rtc-pca21125. + config RTC_DRV_R9701 tristate "Epson RTC-9701JE" help diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 7cf7ad5..2c6af37 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -105,6 +105,7 @@ obj-$(CONFIG_RTC_DRV_NUC900) += rtc-nuc900.o obj-$(CONFIG_RTC_DRV_OMAP) += rtc-omap.o obj-$(CONFIG_RTC_DRV_OPAL) += rtc-opal.o obj-$(CONFIG_RTC_DRV_PALMAS) += rtc-palmas.o +obj-$(CONFIG_RTC_DRV_PCA21125) += rtc-pca21125.o obj-$(CONFIG_RTC_DRV_PCAP) += rtc-pcap.o obj-$(CONFIG_RTC_DRV_PCF2123) += rtc-pcf2123.o obj-$(CONFIG_RTC_DRV_PCF2127) += rtc-pcf2127.o diff --git a/drivers/rtc/rtc-pca21125.c b/drivers/rtc/rtc-pca21125.c index e69de29..8d42e4e 100644 --- a/drivers/rtc/rtc-pca21125.c +++ b/drivers/rtc/rtc-pca21125.c @@ -0,0 +1,164 @@ + /* 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 + + /* 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 + + static int pca21125_read_reg(struct device *dev, unsigned char address, + unsigned char *data) + { + struct spi_device *spi = to_spi_device(dev); + + *data = address | 0x80; + + return spi_write_then_read(spi, data, 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]; + + 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] = PCA21125_CLOCK_BURST | 0x80; + + err = spi_write_then_read(spi, buf, 1, buf, 8); + + if (err) + return err; + + dt->tm_sec = bcd2bin(buf[0]); + dt->tm_min = bcd2bin(buf[1]); + dt->tm_hour = bcd2bin(buf[2] & 0x3F); + dt->tm_mday = bcd2bin(buf[3]); + dt->tm_mon = bcd2bin(buf[4]) - 1; + dt->tm_wday = bcd2bin(buf[5]) - 1; + dt->tm_year = bcd2bin(buf[6]) + 100; + + 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]; + + 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; + } + + buf[0] = bin2bcd(dt->tm_sec); + buf[1] = bin2bcd(dt->tm_min); + buf[2] = (bin2bcd(dt->tm_hour) & 0X3F); + buf[3] = bin2bcd(dt->tm_mday); + buf[4] = bin2bcd(dt->tm_mon + 1); + buf[5] = bin2bcd(dt->tm_wday + 1); + buf[6] = bin2bcd(dt->tm_year % 100); + buf[7] = bin2bcd(0x00); + + /* 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, + }; + + static int pca21125_probe(struct spi_device *spi) + { + struct rtc_device *rtc; + unsigned char data; + int res; + + /* spi setup with pca21125 in mode 3 and bits per word as 8 */ + spi->mode = SPI_MODE_3; + spi->bits_per_word = 8; + spi_setup(spi); + + /* RTC Settings */ + res = pca21125_read_reg(&spi->dev, PCA21125_SECONDS_REG, &data); + if (res) + return res; + + /* Disable the write protect of rtc */ + pca21125_read_reg(&spi->dev, PCA21125_CONTROL_REG, &data); + data = data & ~(1 << 7); + pca21125_write_reg(&spi->dev, PCA21125_CONTROL_REG, data); + + /*Enable oscillator,disable oscillator stop flag, glitch filter*/ + pca21125_read_reg(&spi->dev, PCA21125_STATUS_REG, &data); + data = data & 0x1B; + pca21125_write_reg(&spi->dev, PCA21125_STATUS_REG, data); + + /* display the settings */ + pca21125_read_reg(&spi->dev, PCA21125_CONTROL_REG, &data); + dev_info(&spi->dev, "PCA21125 RTC CTRL Reg = 0x%02x\n", data); + + pca21125_read_reg(&spi->dev, PCA21125_STATUS_REG, &data); + dev_info(&spi->dev, "PCA21125 RTC Status Reg = 0x%02x\n", data); + + 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