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[PATCH] rtc: Add rtc-tx4939 driver (v2)

To: linux-mips@linux-mips.org
Subject: [PATCH] rtc: Add rtc-tx4939 driver (v2)
From: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Date: Fri, 21 Nov 2008 23:31:40 +0900
Cc: ralf@linux-mips.org, rtc-linux@googlegroups.com, a.zummo@towertech.it
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
Add support for RTC in TX4939 SoC.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
---
This patch depends on these rtc patches:
        http://patchwork.ozlabs.org/patch/9302/
        http://patchwork.ozlabs.org/patch/9676/

Changes since v1:
* Use rtc->irq_lock instead of additional private lock
* Implement set_mmss ops instead of set_time ops
* Call rtc_valid_tm()
* Drop ioctl ops (RTC_ALM_SET, RTC_AIE_OFF, RC_AIE_ON)
* Use resource_size()
* Call platform_set_drvdata() early
* Add MODULE_AUTHOR.

 drivers/rtc/Kconfig      |    7 +
 drivers/rtc/Makefile     |    1 +
 drivers/rtc/rtc-tx4939.c |  317 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 325 insertions(+), 0 deletions(-)
 create mode 100644 drivers/rtc/rtc-tx4939.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 165a818..61fcc41 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -683,4 +683,11 @@ config RTC_DRV_STARFIRE
          If you say Y here you will get support for the RTC found on
          Starfire systems.
 
+config RTC_DRV_TX4939
+       tristate "TX4939 SoC"
+       depends on SOC_TX4939
+       help
+         Driver for the internal RTC (Realtime Clock) module found on
+         Toshiba TX4939 SoC.
+
 endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 6e79c91..84dbffd 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -66,6 +66,7 @@ obj-$(CONFIG_RTC_DRV_SH)      += rtc-sh.o
 obj-$(CONFIG_RTC_DRV_STK17TA8) += rtc-stk17ta8.o
 obj-$(CONFIG_RTC_DRV_TEST)     += rtc-test.o
 obj-$(CONFIG_RTC_DRV_TWL4030)  += rtc-twl4030.o
+obj-$(CONFIG_RTC_DRV_TX4939)   += rtc-tx4939.o
 obj-$(CONFIG_RTC_DRV_V3020)    += rtc-v3020.o
 obj-$(CONFIG_RTC_DRV_VR41XX)   += rtc-vr41xx.o
 obj-$(CONFIG_RTC_DRV_WM8350)   += rtc-wm8350.o
diff --git a/drivers/rtc/rtc-tx4939.c b/drivers/rtc/rtc-tx4939.c
new file mode 100644
index 0000000..4ee4857
--- /dev/null
+++ b/drivers/rtc/rtc-tx4939.c
@@ -0,0 +1,317 @@
+/*
+ * TX4939 internal RTC driver
+ * Based on RBTX49xx patch from CELF patch archive.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * (C) Copyright TOSHIBA CORPORATION 2005-2007
+ */
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <asm/txx9/tx4939.h>
+
+struct tx4939rtc_plat_data {
+       struct rtc_device *rtc;
+       struct tx4939_rtc_reg __iomem *rtcreg;
+};
+
+static struct tx4939rtc_plat_data *get_tx4939rtc_plat_data(struct device *dev)
+{
+       return platform_get_drvdata(to_platform_device(dev));
+}
+
+static int tx4939_rtc_cmd(struct tx4939_rtc_reg __iomem *rtcreg, int cmd)
+{
+       int i = 0;
+
+       __raw_writel(cmd, &rtcreg->ctl);
+       /* This might take 30us (next 32.768KHz clock) */
+       while (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_BUSY) {
+               /* timeout on approx. 100us (@ GBUS200MHz) */
+               if (i++ > 200 * 100)
+                       return -EBUSY;
+               cpu_relax();
+       }
+       return 0;
+}
+
+static int tx4939_rtc_set_mmss(struct device *dev, unsigned long secs)
+{
+       struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+       struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+       int i, ret;
+       unsigned char buf[6];
+
+       buf[0] = 0;
+       buf[1] = 0;
+       buf[2] = secs;
+       buf[3] = secs >> 8;
+       buf[4] = secs >> 16;
+       buf[5] = secs >> 24;
+       spin_lock_irq(&pdata->rtc->irq_lock);
+       __raw_writel(0, &rtcreg->adr);
+       for (i = 0; i < 6; i++)
+               __raw_writel(buf[i], &rtcreg->dat);
+       ret = tx4939_rtc_cmd(rtcreg,
+                            TX4939_RTCCTL_COMMAND_SETTIME |
+                            (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
+       spin_unlock_irq(&pdata->rtc->irq_lock);
+       return ret;
+}
+
+static int tx4939_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+       struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+       struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+       int i, ret;
+       unsigned long sec;
+       unsigned char buf[6];
+
+       spin_lock_irq(&pdata->rtc->irq_lock);
+       ret = tx4939_rtc_cmd(rtcreg,
+                            TX4939_RTCCTL_COMMAND_GETTIME |
+                            (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
+       if (ret) {
+               spin_unlock_irq(&pdata->rtc->irq_lock);
+               return ret;
+       }
+       __raw_writel(2, &rtcreg->adr);
+       for (i = 2; i < 6; i++)
+               buf[i] = __raw_readl(&rtcreg->dat);
+       spin_unlock_irq(&pdata->rtc->irq_lock);
+       sec = (buf[5] << 24) | (buf[4] << 16) | (buf[3] << 8) | buf[2];
+       rtc_time_to_tm(sec, tm);
+       return rtc_valid_tm(tm);
+}
+
+static int tx4939_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+       struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+       int i, ret;
+       unsigned long sec;
+       unsigned char buf[6];
+
+       if (alrm->time.tm_sec < 0 ||
+           alrm->time.tm_min < 0 ||
+           alrm->time.tm_hour < 0 ||
+           alrm->time.tm_mday < 0 ||
+           alrm->time.tm_mon < 0 ||
+           alrm->time.tm_year < 0)
+               return -EINVAL;
+       rtc_tm_to_time(&alrm->time, &sec);
+       buf[0] = 0;
+       buf[1] = 0;
+       buf[2] = sec;
+       buf[3] = sec >> 8;
+       buf[4] = sec >> 16;
+       buf[5] = sec >> 24;
+       spin_lock_irq(&pdata->rtc->irq_lock);
+       __raw_writel(0, &rtcreg->adr);
+       for (i = 0; i < 6; i++)
+               __raw_writel(buf[i], &rtcreg->dat);
+       ret = tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_SETALARM |
+                            (alrm->enabled ? TX4939_RTCCTL_ALME : 0));
+       spin_unlock_irq(&pdata->rtc->irq_lock);
+       return ret;
+}
+
+static int tx4939_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+       struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+       int i, ret;
+       unsigned long sec;
+       unsigned char buf[6];
+       u32 ctl;
+
+       spin_lock_irq(&pdata->rtc->irq_lock);
+       ret = tx4939_rtc_cmd(rtcreg,
+                            TX4939_RTCCTL_COMMAND_GETALARM |
+                            (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
+       if (ret) {
+               spin_unlock_irq(&pdata->rtc->irq_lock);
+               return ret;
+       }
+       __raw_writel(2, &rtcreg->adr);
+       for (i = 2; i < 6; i++)
+               buf[i] = __raw_readl(&rtcreg->dat);
+       ctl = __raw_readl(&rtcreg->ctl);
+       alrm->enabled = (ctl & TX4939_RTCCTL_ALME) ? 1 : 0;
+       alrm->pending = (ctl & TX4939_RTCCTL_ALMD) ? 1 : 0;
+       spin_unlock_irq(&pdata->rtc->irq_lock);
+       sec = (buf[5] << 24) | (buf[4] << 16) | (buf[3] << 8) | buf[2];
+       rtc_time_to_tm(sec, &alrm->time);
+       return rtc_valid_tm(&alrm->time);
+}
+
+static int tx4939_rtc_alarm_irq_enable(struct device *dev, unsigned int 
enabled)
+{
+       struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+
+       spin_lock_irq(&pdata->rtc->irq_lock);
+       tx4939_rtc_cmd(pdata->rtcreg,
+                      TX4939_RTCCTL_COMMAND_NOP |
+                      (enabled ? TX4939_RTCCTL_ALME : 0));
+       spin_unlock_irq(&pdata->rtc->irq_lock);
+       return 0;
+}
+
+static irqreturn_t tx4939_rtc_interrupt(int irq, void *dev_id)
+{
+       struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev_id);
+       struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+       unsigned long events = RTC_IRQF;
+
+       spin_lock(&pdata->rtc->irq_lock);
+       if (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALMD) {
+               events |= RTC_AF;
+               tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_NOP);
+       }
+       spin_unlock(&pdata->rtc->irq_lock);
+       rtc_update_irq(pdata->rtc, 1, events);
+       return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops tx4939_rtc_ops = {
+       .read_time              = tx4939_rtc_read_time,
+       .read_alarm             = tx4939_rtc_read_alarm,
+       .set_alarm              = tx4939_rtc_set_alarm,
+       .set_mmss               = tx4939_rtc_set_mmss,
+       .alarm_irq_enable       = tx4939_rtc_alarm_irq_enable,
+};
+
+static ssize_t tx4939_rtc_nvram_read(struct kobject *kobj,
+                                    struct bin_attribute *bin_attr,
+                                    char *buf, loff_t pos, size_t size)
+{
+       struct device *dev = container_of(kobj, struct device, kobj);
+       struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+       struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+       ssize_t count;
+
+       spin_lock_irq(&pdata->rtc->irq_lock);
+       for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
+            count++, size--) {
+               __raw_writel(pos++, &rtcreg->adr);
+               *buf++ = __raw_readl(&rtcreg->dat);
+       }
+       spin_unlock_irq(&pdata->rtc->irq_lock);
+       return count;
+}
+
+static ssize_t tx4939_rtc_nvram_write(struct kobject *kobj,
+                                     struct bin_attribute *bin_attr,
+                                     char *buf, loff_t pos, size_t size)
+{
+       struct device *dev = container_of(kobj, struct device, kobj);
+       struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+       struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+       ssize_t count;
+
+       spin_lock_irq(&pdata->rtc->irq_lock);
+       for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
+            count++, size--) {
+               __raw_writel(pos++, &rtcreg->adr);
+               __raw_writel(*buf++, &rtcreg->dat);
+       }
+       spin_unlock_irq(&pdata->rtc->irq_lock);
+       return count;
+}
+
+static struct bin_attribute tx4939_rtc_nvram_attr = {
+       .attr = {
+               .name = "nvram",
+               .mode = S_IRUGO | S_IWUSR,
+       },
+       .size = TX4939_RTC_REG_RAMSIZE,
+       .read = tx4939_rtc_nvram_read,
+       .write = tx4939_rtc_nvram_write,
+};
+
+static int __init tx4939_rtc_probe(struct platform_device *pdev)
+{
+       struct rtc_device *rtc;
+       struct tx4939rtc_plat_data *pdata;
+       struct resource *res;
+       int irq, ret;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res)
+               return -ENODEV;
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0)
+               return -ENODEV;
+       pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+       if (!pdata)
+               return -ENOMEM;
+       platform_set_drvdata(pdev, pdata);
+
+       if (!devm_request_mem_region(&pdev->dev, res->start,
+                                    resource_size(res), pdev->name))
+               return -EBUSY;
+       pdata->rtcreg = devm_ioremap(&pdev->dev, res->start,
+                                    resource_size(res));
+       if (!pdata->rtcreg)
+               return -EBUSY;
+
+       tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
+       if (devm_request_irq(&pdev->dev, irq, tx4939_rtc_interrupt,
+                            IRQF_DISABLED | IRQF_SHARED,
+                            pdev->name, &pdev->dev) < 0) {
+               return -EBUSY;
+       }
+       rtc = rtc_device_register(pdev->name, &pdev->dev,
+                                 &tx4939_rtc_ops, THIS_MODULE);
+       if (IS_ERR(rtc))
+               return PTR_ERR(rtc);
+       pdata->rtc = rtc;
+       ret = sysfs_create_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
+       if (ret)
+               rtc_device_unregister(rtc);
+       return ret;
+}
+
+static int __exit tx4939_rtc_remove(struct platform_device *pdev)
+{
+       struct tx4939rtc_plat_data *pdata = platform_get_drvdata(pdev);
+       struct rtc_device *rtc = pdata->rtc;
+
+       spin_lock_irq(&rtc->irq_lock);
+       tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
+       spin_unlock_irq(&rtc->irq_lock);
+       sysfs_remove_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
+       rtc_device_unregister(rtc);
+       platform_set_drvdata(pdev, NULL);
+       return 0;
+}
+
+static struct platform_driver tx4939_rtc_driver = {
+       .remove         = __exit_p(tx4939_rtc_remove),
+       .driver         = {
+               .name   = "tx4939rtc",
+               .owner  = THIS_MODULE,
+       },
+};
+
+static int __init tx4939rtc_init(void)
+{
+       return platform_driver_probe(&tx4939_rtc_driver, tx4939_rtc_probe);
+}
+
+static void __exit tx4939rtc_exit(void)
+{
+       platform_driver_unregister(&tx4939_rtc_driver);
+}
+
+module_init(tx4939rtc_init);
+module_exit(tx4939rtc_exit);
+
+MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
+MODULE_DESCRIPTION("TX4939 internal RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:tx4939rtc");
-- 
1.5.6.3


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