3 files changed, 273 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 4511ddc1ac31..f15cddfeb897 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -987,6 +987,17 @@ config RTC_DRV_NUC900
           If you say yes here you get support for the RTC subsystem of the
           NUC910/NUC920 used in embedded systems.
 
+config RTC_DRV_OPAL
+        tristate "IBM OPAL RTC driver"
+        depends on PPC_POWERNV
+        default y
+        help
+          If you say yes here you get support for the PowerNV platform RTC
+          driver based on OPAL interfaces.
+
+          This driver can also be built as a module. If so, the module
+          will be called rtc-opal.
+
 comment "on-CPU RTC drivers"
 
 config RTC_DRV_DAVINCI
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index b188323c096a..c8ef3e1e6ccd 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -92,6 +92,7 @@ obj-$(CONFIG_RTC_DRV_MSM6242)	+= rtc-msm6242.o
 obj-$(CONFIG_RTC_DRV_MPC5121)   += rtc-mpc5121.o
 obj-$(CONFIG_RTC_DRV_MV)        += rtc-mv.o
 obj-$(CONFIG_RTC_DRV_NUC900)    += rtc-nuc900.o
+obj-$(CONFIG_RTC_DRV_OPAL)      += rtc-opal.o
 obj-$(CONFIG_RTC_DRV_OMAP)      += rtc-omap.o
 obj-$(CONFIG_RTC_DRV_PALMAS)    += rtc-palmas.o
 obj-$(CONFIG_RTC_DRV_PCAP)      += rtc-pcap.o
diff --git a/drivers/rtc/rtc-opal.c b/drivers/rtc/rtc-opal.c
new file mode 100644
index 000000000000..95f652165fe9
--- /dev/null
+++ b/drivers/rtc/rtc-opal.c
@@ -0,0 +1,261 @@
+/*
+ * IBM OPAL RTC driver
+ * Copyright (C) 2014 IBM
+ *
+ * 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.
+ */
+
+#define DRVNAME         "rtc-opal"
+#define pr_fmt(fmt)     DRVNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/bcd.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <asm/opal.h>
+#include <asm/firmware.h>
+
+static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
+{
+        tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) +
+                       bcd2bin((y_m_d >> 16) & 0xff)) - 1900;
+        tm->tm_mon  = bcd2bin((y_m_d >> 8) & 0xff) - 1;
+        tm->tm_mday = bcd2bin(y_m_d & 0xff);
+        tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff);
+        tm->tm_min  = bcd2bin((h_m_s_ms >> 48) & 0xff);
+        tm->tm_sec  = bcd2bin((h_m_s_ms >> 40) & 0xff);
+
+        GregorianDay(tm);
+}
+
+static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms)
+{
+        *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;
+        *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;
+        *y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;
+        *y_m_d |= ((u32)bin2bcd(tm->tm_mday));
+
+        *h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;
+        *h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;
+        *h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;
+}
+
+static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm)
+{
+        long rc = OPAL_BUSY;
+        u32 y_m_d;
+        u64 h_m_s_ms;
+        __be32 __y_m_d;
+        __be64 __h_m_s_ms;
+
+        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+                rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
+                if (rc == OPAL_BUSY_EVENT)
+                        opal_poll_events(NULL);
+                else
+                        msleep(10);
+        }
+
+        if (rc != OPAL_SUCCESS)
+                return -EIO;
+
+        y_m_d = be32_to_cpu(__y_m_d);
+        h_m_s_ms = be64_to_cpu(__h_m_s_ms);
+        opal_to_tm(y_m_d, h_m_s_ms, tm);
+
+        return 0;
+}
+
+static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm)
+{
+        long rc = OPAL_BUSY;
+        u32 y_m_d = 0;
+        u64 h_m_s_ms = 0;
+
+        tm_to_opal(tm, &y_m_d, &h_m_s_ms);
+        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+                rc = opal_rtc_write(y_m_d, h_m_s_ms);
+                if (rc == OPAL_BUSY_EVENT)
+                        opal_poll_events(NULL);
+                else
+                        msleep(10);
+        }
+
+        return rc == OPAL_SUCCESS ? 0 : -EIO;
+}
+
+/*
+ * TPO  Timed Power-On
+ *
+ * TPO get/set OPAL calls care about the hour and min and to make it consistent
+ * with the rtc utility time conversion functions, we use the 'u64' to store
+ * its value and perform bit shift by 32 before use..
+ */
+static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)
+{
+        __be32 __y_m_d, __h_m;
+        struct opal_msg msg;
+        int rc, token;
+        u64 h_m_s_ms;
+        u32 y_m_d;
+
+        token = opal_async_get_token_interruptible();
+        if (token < 0) {
+                if (token != -ERESTARTSYS)
+                        pr_err("Failed to get the async token\n");
+
+                return token;
+        }
+
+        rc = opal_tpo_read(token, &__y_m_d, &__h_m);
+        if (rc != OPAL_ASYNC_COMPLETION) {
+                rc = -EIO;
+                goto exit;
+        }
+
+        rc = opal_async_wait_response(token, &msg);
+        if (rc) {
+                rc = -EIO;
+                goto exit;
+        }
+
+        rc = be64_to_cpu(msg.params[1]);
+        if (rc != OPAL_SUCCESS) {
+                rc = -EIO;
+                goto exit;
+        }
+
+        y_m_d = be32_to_cpu(__y_m_d);
+        h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32);
+        opal_to_tm(y_m_d, h_m_s_ms, &alarm->time);
+
+exit:
+        opal_async_release_token(token);
+        return rc;
+}
+
+/* Set Timed Power-On */
+static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)
+{
+        u64 h_m_s_ms = 0, token;
+        struct opal_msg msg;
+        u32 y_m_d = 0;
+        int rc;
+
+        tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms);
+
+        token = opal_async_get_token_interruptible();
+        if (token < 0) {
+                if (token != -ERESTARTSYS)
+                        pr_err("Failed to get the async token\n");
+
+                return token;
+        }
+
+        /* TPO, we care about hour and minute */
+        rc = opal_tpo_write(token, y_m_d,
+                            (u32)((h_m_s_ms >> 32) & 0xffff0000));
+        if (rc != OPAL_ASYNC_COMPLETION) {
+                rc = -EIO;
+                goto exit;
+        }
+
+        rc = opal_async_wait_response(token, &msg);
+        if (rc) {
+                rc = -EIO;
+                goto exit;
+        }
+
+        rc = be64_to_cpu(msg.params[1]);
+        if (rc != OPAL_SUCCESS)
+                rc = -EIO;
+
+exit:
+        opal_async_release_token(token);
+        return rc;
+}
+
+static const struct rtc_class_ops opal_rtc_ops = {
+        .read_time      = opal_get_rtc_time,
+        .set_time       = opal_set_rtc_time,
+        .read_alarm     = opal_get_tpo_time,
+        .set_alarm      = opal_set_tpo_time,
+};
+
+static int opal_rtc_probe(struct platform_device *pdev)
+{
+        struct rtc_device *rtc;
+
+        if (pdev->dev.of_node && of_get_property(pdev->dev.of_node, "has-tpo",
+                                                 NULL))
+                device_set_wakeup_capable(&pdev->dev, true);
+
+        rtc = devm_rtc_device_register(&pdev->dev, DRVNAME, &opal_rtc_ops,
+                                       THIS_MODULE);
+        if (IS_ERR(rtc))
+                return PTR_ERR(rtc);
+
+        rtc->uie_unsupported = 1;
+
+        return 0;
+}
+
+static const struct of_device_id opal_rtc_match[] = {
+        {
+                .compatible     = "ibm,opal-rtc",
+        },
+        { }
+};
+MODULE_DEVICE_TABLE(of, opal_rtc_match);
+
+static const struct platform_device_id opal_rtc_driver_ids[] = {
+        {
+                .name           = "opal-rtc",
+        },
+        { }
+};
+MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids);
+
+static struct platform_driver opal_rtc_driver = {
+        .probe          = opal_rtc_probe,
+        .id_table       = opal_rtc_driver_ids,
+        .driver         = {
+                .name           = DRVNAME,
+                .owner          = THIS_MODULE,
+                .of_match_table = opal_rtc_match,
+        },
+};
+
+static int __init opal_rtc_init(void)
+{
+        if (!firmware_has_feature(FW_FEATURE_OPAL))
+                return -ENODEV;
+
+        return platform_driver_register(&opal_rtc_driver);
+}
+
+static void __exit opal_rtc_exit(void)
+{
+        platform_driver_unregister(&opal_rtc_driver);
+}
+
+MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("IBM OPAL RTC driver");
+MODULE_LICENSE("GPL");
+
+module_init(opal_rtc_init);
+module_exit(opal_rtc_exit);