mfd: tps6586x: add RTC driver for TI TPS6586x
Gary King [Sat, 14 Aug 2010 18:17:54 +0000 (11:17 -0700)]
Change-Id: Ie22a19b662fda6365b1c514aaf83c9de12fabbd4
Signed-off-by: Gary King <gking@nvidia.com>

drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-tps6586x.c [new file with mode: 0644]

index 5a538fc..fe4cc66 100644 (file)
@@ -304,6 +304,13 @@ config RTC_DRV_DM355EVM
        help
          Supports the RTC firmware in the MSP430 on the DM355 EVM.
 
+config RTC_DRV_TPS6586X
+       tristate "TI TPS6586X RTC"
+       depends on I2C
+       select MFD_TPS6586X
+       help
+         This driver supports TPS6586X RTC
+
 config RTC_DRV_TWL92330
        boolean "TI TWL92330/Menelaus"
        depends on MENELAUS
index 6e69823..9772de4 100644 (file)
@@ -101,6 +101,7 @@ obj-$(CONFIG_RTC_DRV_SUN4V) += rtc-sun4v.o
 obj-$(CONFIG_RTC_DRV_TEGRA)    += rtc-tegra.o
 obj-$(CONFIG_RTC_DRV_TEST)     += rtc-test.o
 obj-$(CONFIG_RTC_DRV_TILE)     += rtc-tile.o
+obj-$(CONFIG_RTC_DRV_TPS6586X) += rtc-tps6586x.o
 obj-$(CONFIG_RTC_DRV_TWL4030)  += rtc-twl.o
 obj-$(CONFIG_RTC_DRV_TX4939)   += rtc-tx4939.o
 obj-$(CONFIG_RTC_DRV_V3020)    += rtc-v3020.o
diff --git a/drivers/rtc/rtc-tps6586x.c b/drivers/rtc/rtc-tps6586x.c
new file mode 100644 (file)
index 0000000..f898f40
--- /dev/null
@@ -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 <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mfd/tps6586x.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+#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");