From 428377879090cd29429b2f9d77b37a2264d72360 Mon Sep 17 00:00:00 2001 From: Gary King Date: Sat, 14 Aug 2010 11:17:54 -0700 Subject: mfd: tps6586x: add RTC driver for TI TPS6586x Change-Id: Ie22a19b662fda6365b1c514aaf83c9de12fabbd4 Signed-off-by: Gary King --- drivers/rtc/rtc-tps6586x.c | 203 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 203 insertions(+) create mode 100644 drivers/rtc/rtc-tps6586x.c (limited to 'drivers/rtc/rtc-tps6586x.c') diff --git a/drivers/rtc/rtc-tps6586x.c b/drivers/rtc/rtc-tps6586x.c new file mode 100644 index 000000000000..f898f40f88ce --- /dev/null +++ b/drivers/rtc/rtc-tps6586x.c @@ -0,0 +1,203 @@ +/* + * drivers/rtc/rtc-tps6586x.c + * + * RTC driver for TI TPS6586x + * + * Copyright (c) 2010, NVIDIA Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define TPS_EPOCH 2009 + +#define RTC_CTRL 0xc0 +# define RTC_ENABLE (1 << 5) /* enables tick updates */ +# define RTC_HIRES (1 << 4) /* 1Khz or 32Khz updates */ +#define RTC_ALARM1_HI 0xc1 +#define RTC_COUNT4 0xc6 + +struct tps6586x_rtc { + unsigned long epoch_start; + struct rtc_device *rtc; +}; + +static inline struct device *to_tps6586x_dev(struct device *dev) +{ + return dev->parent; +} + +static int tps6586x_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct tps6586x_rtc *rtc = dev_get_drvdata(dev); + struct device *tps_dev = to_tps6586x_dev(dev); + unsigned long long ticks = 0; + unsigned long seconds; + u8 buff[5]; + int err; + int i; + + err = tps6586x_reads(tps_dev, RTC_COUNT4, sizeof(buff), buff); + if (err < 0) { + dev_err(dev, "failed to read counter\n"); + return err; + } + + for (i = 0; i < sizeof(buff); i++) { + ticks <<= 8; + ticks |= buff[i]; + } + + seconds = ticks >> 10; + + seconds += rtc->epoch_start; + rtc_time_to_tm(seconds, tm); + return rtc_valid_tm(tm); +} + +static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct tps6586x_rtc *rtc = dev_get_drvdata(dev); + struct device *tps_dev = to_tps6586x_dev(dev); + unsigned long long ticks; + unsigned long seconds; + u8 buff[5]; + int err; + + rtc_tm_to_time(tm, &seconds); + + if (WARN_ON(seconds < rtc->epoch_start)) { + dev_err(dev, "requested time unsupported\n"); + return -EINVAL; + } + + seconds -= rtc->epoch_start; + + ticks = seconds << 10; + buff[0] = (ticks >> 32) & 0xff; + buff[1] = (ticks >> 24) & 0xff; + buff[2] = (ticks >> 16) & 0xff; + buff[3] = (ticks >> 8) & 0xff; + buff[4] = ticks & 0xff; + + dev_info(dev, "setting time to %lu seconds (%llu ticks)\n", + seconds, ticks); + + + err = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE); + if (err < 0) { + dev_err(dev, "failed to clear RTC_ENABLE\n"); + return err; + } + + err = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff); + if (err < 0) { + dev_err(dev, "failed to program new time\n"); + return err; + } + + err = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE); + if (err < 0) { + dev_err(dev, "failed to set RTC_ENABLE\n"); + return err; + } + + return 0; +} + +static const struct rtc_class_ops tps6586x_rtc_ops = { + .read_time = tps6586x_rtc_read_time, + .set_time = tps6586x_rtc_set_time, +}; + +static int __devinit tps6586x_rtc_probe(struct platform_device *pdev) +{ + struct device *tps_dev = to_tps6586x_dev(&pdev->dev); + struct tps6586x_rtc *rtc; + int err; + + rtc = kzalloc(sizeof(*rtc), GFP_KERNEL); + + if (!rtc) + return -ENOMEM; + + rtc->epoch_start = mktime(TPS_EPOCH, 1, 1, 0, 0, 0); + rtc->rtc = rtc_device_register("tps6586x-rtc", &pdev->dev, + &tps6586x_rtc_ops, THIS_MODULE); + + if (IS_ERR(rtc->rtc)) { + err = PTR_ERR(rtc->rtc); + goto fail; + } + + /* disable high-res mode, enable tick counting */ + err = tps6586x_update(tps_dev, RTC_CTRL, + (RTC_ENABLE | RTC_HIRES), RTC_ENABLE); + if (err < 0) { + dev_err(&pdev->dev, "unable to start counter\n"); + goto fail; + } + + dev_set_drvdata(&pdev->dev, rtc); + return 0; + +fail: + if (!IS_ERR_OR_NULL(rtc->rtc)) + rtc_device_unregister(rtc->rtc); + kfree(rtc); + return err; +} + +static int __devexit tps6586x_rtc_remove(struct platform_device *pdev) +{ + struct tps6586x_rtc *rtc = dev_get_drvdata(&pdev->dev); + + rtc_device_unregister(rtc->rtc); + kfree(rtc); + return 0; +} + +static struct platform_driver tps6586x_rtc_driver = { + .driver = { + .name = "tps6586x-rtc", + .owner = THIS_MODULE, + }, + .probe = tps6586x_rtc_probe, + .remove = __devexit_p(tps6586x_rtc_remove), +}; + +static int __init tps6586x_rtc_init(void) +{ + return platform_driver_register(&tps6586x_rtc_driver); +} +module_init(tps6586x_rtc_init); + +static void __exit tps6586x_rtc_exit(void) +{ + platform_driver_unregister(&tps6586x_rtc_driver); +} +module_exit(tps6586x_rtc_exit); + +MODULE_DESCRIPTION("TI TPS6586x RTC driver"); +MODULE_AUTHOR("NVIDIA Corporation"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3