2011-03-26 16:53:32

by Anirudh Ghayal

[permalink] [raw]
Subject: [PATCH 3/3] drivers: rtc: Add support for Qualcomm PMIC8xxx RTC

PMIC8xxx is Qualcomm's power management IC. A
32-bit RTC is housed inside this PMIC. The RTC driver
uses SSBI to communicate with the RTC module.

Cc: Alessandro Zummo <[email protected]>
Cc: Lars-Peter Clausen <[email protected]>
Signed-off-by: Anirudh Ghayal <[email protected]>
---
drivers/rtc/Kconfig | 9 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-pm8xxx.c | 567 ++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/pm8xxx/rtc.h | 25 ++
4 files changed, 602 insertions(+), 0 deletions(-)
create mode 100644 drivers/rtc/rtc-pm8xxx.c
create mode 100644 include/linux/mfd/pm8xxx/rtc.h

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index e187887..a66672a 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -995,4 +995,13 @@ config RTC_DRV_TEGRA
This drive can also be built as a module. If so, the module
will be called rtc-tegra.

+config RTC_DRV_PM8XXX
+ tristate "Qualcomm PMIC8XXX RTC"
+ depends on MFD_PM8XXX
+ help
+ Say Y here if you want to support the Qualcomm PMIC8XXX RTC.
+
+ To compile this driver as a module, choose M here: the
+ module will be called rtc-pm8xxx.
+
endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index ca91c3c..ff40366 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -72,6 +72,7 @@ obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o
obj-$(CONFIG_RTC_DRV_PCF2123) += rtc-pcf2123.o
obj-$(CONFIG_RTC_DRV_PCF50633) += rtc-pcf50633.o
+obj-$(CONFIG_RTC_DRV_PM8XXX) += rtc-pm8xxx.o
obj-$(CONFIG_RTC_DRV_PL030) += rtc-pl030.o
obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o
obj-$(CONFIG_RTC_DRV_PS3) += rtc-ps3.o
diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
new file mode 100644
index 0000000..ce2dad3
--- /dev/null
+++ b/drivers/rtc/rtc-pm8xxx.c
@@ -0,0 +1,567 @@
+/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/rtc.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include<linux/spinlock.h>
+
+#include <linux/mfd/pm8xxx/core.h>
+#include <linux/mfd/pm8xxx/rtc.h>
+
+/* RTC Register offsets from RTC CTRL REG */
+#define PM8XXX_ALARM_CTRL_OFFSET 0x01
+#define PM8XXX_RTC_WRITE_OFFSET 0x02
+#define PM8XXX_RTC_READ_OFFSET 0x06
+#define PM8XXX_ALARM_RW_OFFSET 0x0A
+
+/* RTC_CTRL register bit fields */
+#define PM8xxx_RTC_ENABLE BIT(7)
+#define PM8xxx_RTC_ALARM_ENABLE BIT(1)
+#define PM8xxx_RTC_ALARM_CLEAR BIT(0)
+
+#define NUM_8_BIT_RTC_REGS 0x4
+
+/**
+ * struct pm8xxx_rtc - rtc driver internal structure
+ * @rtc: rtc device for this driver
+ * @rtc_alarm_irq: rtc alarm irq number
+ */
+struct pm8xxx_rtc {
+ struct rtc_device *rtc;
+ int rtc_alarm_irq;
+ int rtc_base;
+ int rtc_read_base;
+ int rtc_write_base;
+ int alarm_rw_base;
+ u8 ctrl_reg;
+ struct device *parent;
+ spinlock_t ctrl_reg_lock;
+};
+
+/*
+ * The RTC registers need to be read/written one byte at a time. This is a
+ * hardware limitation.
+ */
+static int pm8xxx_read_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
+ int base, int count)
+{
+ int i, rc;
+
+ for (i = 0; i < count; i++) {
+ rc = pm8xxx_readb(rtc_dd->parent, base + i, &rtc_val[i]);
+ if (rc < 0) {
+ pr_err("PM8xxx read failed\n");
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+static int pm8xxx_write_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
+ int base, int count)
+{
+ int i, rc;
+
+ for (i = 0; i < count; i++) {
+ rc = pm8xxx_writeb(rtc_dd->parent, base + i, rtc_val[i]);
+ if (rc < 0) {
+ pr_err("PM8xxx write failed\n");
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+
+/*
+ * Steps to write the RTC registers.
+ * 1. Disable alarm if enabled.
+ * 2. Write 0x00 to LSB.
+ * 3. Write Byte[1], Byte[2], Byte[3] then Byte[0].
+ * 4. Enable alarm if disabled in step 1.
+ */
+static int
+pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ int rc;
+ unsigned long secs, irq_flags;
+ u8 value[4], reg = 0, alarm_enabled = 0, ctrl_reg;
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+
+ rtc_tm_to_time(tm, &secs);
+
+ value[0] = secs & 0xFF;
+ value[1] = (secs >> 8) & 0xFF;
+ value[2] = (secs >> 16) & 0xFF;
+ value[3] = (secs >> 24) & 0xFF;
+
+ dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs);
+
+ spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
+ ctrl_reg = rtc_dd->ctrl_reg;
+
+ if (ctrl_reg & PM8xxx_RTC_ALARM_ENABLE) {
+ alarm_enabled = 1;
+ ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
+ 1);
+ if (rc < 0) {
+ dev_err(dev, "PM8xxx write failed\n");
+ goto rtc_rw_fail;
+ }
+ } else
+ spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+ /* Write Byte[1], Byte[2], Byte[3], Byte[0] */
+ /* Write 0 to Byte[0] */
+ reg = 0;
+ rc = pm8xxx_write_wrapper(rtc_dd, &reg, rtc_dd->rtc_write_base, 1);
+ if (rc < 0) {
+ dev_err(dev, "PM8xxx write failed\n");
+ goto rtc_rw_fail;
+ }
+
+ /* Write Byte[1], Byte[2], Byte[3] */
+ rc = pm8xxx_write_wrapper(rtc_dd, value + 1,
+ rtc_dd->rtc_write_base + 1, 3);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC registers failed\n");
+ goto rtc_rw_fail;
+ }
+
+ /* Write Byte[0] */
+ rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->rtc_write_base, 1);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC register failed\n");
+ goto rtc_rw_fail;
+ }
+
+ if (alarm_enabled) {
+ ctrl_reg |= PM8xxx_RTC_ALARM_ENABLE;
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
+ 1);
+ if (rc < 0) {
+ dev_err(dev, "PM8xxx write failed\n");
+ goto rtc_rw_fail;
+ }
+ }
+
+ rtc_dd->ctrl_reg = ctrl_reg;
+
+rtc_rw_fail:
+ if (alarm_enabled)
+ spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+ return rc;
+}
+
+static int
+pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ int rc;
+ u8 value[4], reg;
+ unsigned long secs;
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+
+ rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->rtc_read_base,
+ NUM_8_BIT_RTC_REGS);
+ if (rc < 0) {
+ dev_err(dev, "RTC time read failed\n");
+ return rc;
+ }
+
+ /*
+ * Read the LSB again and check if there has been a carry over.
+ * If there is, redo the read operation.
+ */
+ rc = pm8xxx_read_wrapper(rtc_dd, &reg, rtc_dd->rtc_read_base, 1);
+ if (rc < 0) {
+ dev_err(dev, "PM8xxx read failed\n");
+ return rc;
+ }
+
+ if (unlikely(reg < value[0])) {
+ rc = pm8xxx_read_wrapper(rtc_dd, value,
+ rtc_dd->rtc_read_base, NUM_8_BIT_RTC_REGS);
+ if (rc < 0) {
+ dev_err(dev, "RTC time read failed\n");
+ return rc;
+ }
+ }
+
+ secs = value[0] | (value[1] << 8) | (value[2] << 16) \
+ | (value[3] << 24);
+
+ rtc_time_to_tm(secs, tm);
+
+ rc = rtc_valid_tm(tm);
+ if (rc < 0) {
+ dev_err(dev, "Invalid time read from PM8xxx\n");
+ return rc;
+ }
+
+ dev_dbg(dev, "secs = %lu, h:m:s == %d:%d:%d, d/m/y = %d/%d/%d\n",
+ secs, tm->tm_hour, tm->tm_min, tm->tm_sec,
+ tm->tm_mday, tm->tm_mon, tm->tm_year);
+
+ return 0;
+}
+
+static int
+pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ int rc;
+ u8 value[4], ctrl_reg;
+ unsigned long secs, secs_rtc, irq_flags;
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+ struct rtc_time rtc_tm;
+
+ rtc_tm_to_time(&alarm->time, &secs);
+
+ /*
+ * Read the current RTC time and verify if the alarm time is in the
+ * past. If yes, return invalid.
+ */
+ rc = pm8xxx_rtc_read_time(dev, &rtc_tm);
+ if (rc < 0) {
+ dev_err(dev, "Unamble to read RTC time\n");
+ return -EINVAL;
+ }
+
+ rtc_tm_to_time(&rtc_tm, &secs_rtc);
+ if (secs < secs_rtc) {
+ dev_err(dev, "Trying to set alarm in the past\n");
+ return -EINVAL;
+ }
+
+ value[0] = secs & 0xFF;
+ value[1] = (secs >> 8) & 0xFF;
+ value[2] = (secs >> 16) & 0xFF;
+ value[3] = (secs >> 24) & 0xFF;
+
+ spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+ rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
+ NUM_8_BIT_RTC_REGS);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC ALARM registers failed\n");
+ goto rtc_rw_fail;
+ }
+
+ ctrl_reg = rtc_dd->ctrl_reg;
+ ctrl_reg = (alarm->enabled) ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
+ (ctrl_reg & ~PM8xxx_RTC_ALARM_ENABLE);
+
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
+ if (rc < 0) {
+ dev_err(dev, "PM8xxx write failed\n");
+ goto rtc_rw_fail;
+ }
+
+ rtc_dd->ctrl_reg = ctrl_reg;
+
+ dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
+ alarm->time.tm_hour, alarm->time.tm_min,
+ alarm->time.tm_sec, alarm->time.tm_mday,
+ alarm->time.tm_mon, alarm->time.tm_year);
+rtc_rw_fail:
+ spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+ return rc;
+}
+
+static int
+pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ int rc;
+ u8 value[4];
+ unsigned long secs;
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+
+ rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
+ NUM_8_BIT_RTC_REGS);
+ if (rc < 0) {
+ dev_err(dev, "RTC alarm time read failed\n");
+ return rc;
+ }
+
+ secs = value[0] | (value[1] << 8) | (value[2] << 16) | \
+ (value[3] << 24);
+
+ rtc_time_to_tm(secs, &alarm->time);
+
+ rc = rtc_valid_tm(&alarm->time);
+ if (rc < 0) {
+ dev_err(dev, "Invalid time read from PM8xxx\n");
+ return rc;
+ }
+
+ dev_dbg(dev, "Alarm set for - h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
+ alarm->time.tm_hour, alarm->time.tm_min,
+ alarm->time.tm_sec, alarm->time.tm_mday,
+ alarm->time.tm_mon, alarm->time.tm_year);
+
+ return 0;
+}
+
+
+static int
+pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ int rc;
+ unsigned long irq_flags;
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+ u8 ctrl_reg;
+
+ spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
+ ctrl_reg = rtc_dd->ctrl_reg;
+ ctrl_reg = (enabled) ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
+ (ctrl_reg & ~PM8xxx_RTC_ALARM_ENABLE);
+
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
+ if (rc < 0) {
+ dev_err(dev, "PM8xxx write failed\n");
+ goto rtc_rw_fail;
+ }
+
+ rtc_dd->ctrl_reg = ctrl_reg;
+
+rtc_rw_fail:
+ spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+ return rc;
+}
+
+static struct rtc_class_ops pm8xxx_rtc_ops = {
+ .read_time = pm8xxx_rtc_read_time,
+ .set_alarm = pm8xxx_rtc_set_alarm,
+ .read_alarm = pm8xxx_rtc_read_alarm,
+ .alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
+{
+ struct pm8xxx_rtc *rtc_dd = dev_id;
+ u8 ctrl_reg;
+ int rc;
+ unsigned long irq_flags;
+
+ rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
+
+ spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+ /* Clear the alarm enable bit */
+ ctrl_reg = rtc_dd->ctrl_reg;
+ ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
+
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
+ if (rc < 0) {
+ spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+ pr_err("PM8xxx write failed!\n");
+ goto rtc_alarm_handled;
+ }
+
+ rtc_dd->ctrl_reg = ctrl_reg;
+ spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+ /* Clear RTC alarm register */
+ rc = pm8xxx_read_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base +
+ PM8XXX_ALARM_CTRL_OFFSET, 1);
+ if (rc < 0) {
+ pr_err("PM8xxx write failed!\n");
+ goto rtc_alarm_handled;
+ }
+
+ ctrl_reg &= ~PM8xxx_RTC_ALARM_CLEAR;
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base +
+ PM8XXX_ALARM_CTRL_OFFSET, 1);
+ if (rc < 0)
+ pr_err("PM8xxx write failed!\n");
+
+rtc_alarm_handled:
+ return IRQ_HANDLED;
+}
+
+static int __devinit pm8xxx_rtc_probe(struct platform_device *pdev)
+{
+ int rc;
+ u8 ctrl_reg;
+ bool rtc_write_enable = false;
+ struct pm8xxx_rtc *rtc_dd;
+ struct resource *rtc_resource;
+ const struct pm8xxx_rtc_platform_data *pdata =
+ pdev->dev.platform_data;
+
+ if (pdata != NULL)
+ rtc_write_enable = pdata->rtc_write_enable;
+
+ rtc_dd = kzalloc(sizeof(*rtc_dd), GFP_KERNEL);
+ if (rtc_dd == NULL) {
+ dev_err(&pdev->dev, "Unable to allocate memory!\n");
+ return -ENOMEM;
+ }
+
+ /* Initialise spinlock to protect RTC cntrol register */
+ spin_lock_init(&rtc_dd->ctrl_reg_lock);
+
+ rtc_dd->rtc_alarm_irq = platform_get_irq(pdev, 0);
+ if (!rtc_dd->rtc_alarm_irq) {
+ dev_err(&pdev->dev, "Alarm IRQ resource absent!\n");
+ rc = -ENXIO;
+ goto fail_rtc_enable;
+ }
+
+ rtc_resource = platform_get_resource_byname(pdev, IORESOURCE_IO,
+ "pmic_rtc_base");
+ if (rtc_resource)
+ rtc_dd->rtc_base = rtc_resource->start;
+ if (!rtc_dd->rtc_base) {
+ dev_err(&pdev->dev, "RTC IO resource absent!\n");
+ rc = -ENXIO;
+ goto fail_rtc_enable;
+ }
+
+ /* Setup RTC register addresses */
+ rtc_dd->rtc_write_base = rtc_dd->rtc_base + PM8XXX_RTC_WRITE_OFFSET;
+ rtc_dd->rtc_read_base = rtc_dd->rtc_base + PM8XXX_RTC_READ_OFFSET;
+ rtc_dd->alarm_rw_base = rtc_dd->rtc_base + PM8XXX_ALARM_RW_OFFSET;
+
+ rtc_dd->parent = pdev->dev.parent;
+
+ /* Check if the RTC is on, else turn it on */
+ rc = pm8xxx_read_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "PM8xxx read failed!\n");
+ goto fail_rtc_enable;
+ }
+
+ if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) {
+ ctrl_reg |= PM8xxx_RTC_ENABLE;
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
+ 1);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "PM8xxx write failed!\n");
+ goto fail_rtc_enable;
+ }
+ }
+
+ rtc_dd->ctrl_reg = ctrl_reg;
+ if (rtc_write_enable == true)
+ pm8xxx_rtc_ops.set_time = pm8xxx_rtc_set_time,
+
+ platform_set_drvdata(pdev, rtc_dd);
+
+ /* Register the RTC device */
+ rtc_dd->rtc = rtc_device_register("pm8xxx_rtc", &pdev->dev,
+ &pm8xxx_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc_dd->rtc)) {
+ dev_err(&pdev->dev, "%s: RTC registration failed (%ld)\n",
+ __func__, PTR_ERR(rtc_dd->rtc));
+ rc = PTR_ERR(rtc_dd->rtc);
+ goto fail_rtc_enable;
+ }
+
+ /* Request the alarm IRQ */
+ rc = request_any_context_irq(rtc_dd->rtc_alarm_irq,
+ pm8xxx_alarm_trigger, IRQF_TRIGGER_RISING,
+ "pm8xxx_rtc_alarm", rtc_dd);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Request IRQ failed (%d)\n", rc);
+ goto fail_req_irq;
+ }
+
+ device_init_wakeup(&pdev->dev, 1);
+
+ dev_dbg(&pdev->dev, "Probe success !!\n");
+
+ return 0;
+
+fail_req_irq:
+ rtc_device_unregister(rtc_dd->rtc);
+fail_rtc_enable:
+ platform_set_drvdata(pdev, NULL);
+ kfree(rtc_dd);
+ return rc;
+}
+
+#ifdef CONFIG_PM
+static int pm8xxx_rtc_resume(struct device *dev)
+{
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev))
+ disable_irq_wake(rtc_dd->rtc_alarm_irq);
+
+ return 0;
+}
+
+static int pm8xxx_rtc_suspend(struct device *dev)
+{
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev))
+ enable_irq_wake(rtc_dd->rtc_alarm_irq);
+
+ return 0;
+}
+
+static const struct dev_pm_ops pm8xxx_rtc_pm_ops = {
+ .suspend = pm8xxx_rtc_suspend,
+ .resume = pm8xxx_rtc_resume,
+};
+#endif
+static int __devexit pm8xxx_rtc_remove(struct platform_device *pdev)
+{
+ struct pm8xxx_rtc *rtc_dd = platform_get_drvdata(pdev);
+
+ device_init_wakeup(&pdev->dev, 0);
+ free_irq(rtc_dd->rtc_alarm_irq, rtc_dd);
+ rtc_device_unregister(rtc_dd->rtc);
+ platform_set_drvdata(pdev, NULL);
+ kfree(rtc_dd);
+
+ return 0;
+}
+
+static struct platform_driver pm8xxx_rtc_driver = {
+ .probe = pm8xxx_rtc_probe,
+ .remove = __devexit_p(pm8xxx_rtc_remove),
+ .driver = {
+ .name = PM8XXX_RTC_DEV_NAME,
+ .owner = THIS_MODULE,
+#ifdef CONFIG_PM
+ .pm = &pm8xxx_rtc_pm_ops,
+#endif
+ },
+};
+
+static int __init pm8xxx_rtc_init(void)
+{
+ return platform_driver_register(&pm8xxx_rtc_driver);
+}
+module_init(pm8xxx_rtc_init);
+
+static void __exit pm8xxx_rtc_exit(void)
+{
+ platform_driver_unregister(&pm8xxx_rtc_driver);
+}
+module_exit(pm8xxx_rtc_exit);
+
+MODULE_ALIAS("platform:rtc-pm8xxx");
+MODULE_DESCRIPTION("PMIC8xxx RTC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Anirudh Ghayal <[email protected]>");
diff --git a/include/linux/mfd/pm8xxx/rtc.h b/include/linux/mfd/pm8xxx/rtc.h
new file mode 100644
index 0000000..2528e1d
--- /dev/null
+++ b/include/linux/mfd/pm8xxx/rtc.h
@@ -0,0 +1,25 @@
+/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#ifndef __RTC_PM8XXX_H__
+#define __RTC_PM8XXX_H__
+
+#define PM8XXX_RTC_DEV_NAME "rtc-pm8xxx"
+/**
+ * struct pm8058_rtc_pdata - RTC driver platform data
+ * @rtc_write_enable: variable stating RTC write capability
+ */
+struct pm8xxx_rtc_platform_data {
+ bool rtc_write_enable;
+};
+
+#endif /* __RTC_PM8XXX_H__ */
--
1.7.3.5


2011-03-31 16:48:10

by Wan ZongShun

[permalink] [raw]
Subject: Re: [rtc-linux] [PATCH 3/3] drivers: rtc: Add support for Qualcomm PMIC8xxx RTC

Hi Anirudh,

Some advice below:

2011/3/27 Anirudh Ghayal <[email protected]>:
> PMIC8xxx is Qualcomm's power management IC. A
> 32-bit RTC is housed inside this PMIC. The RTC driver
> uses SSBI to communicate with the RTC module.
>
> Cc: Alessandro Zummo <[email protected]>
> Cc: Lars-Peter Clausen <[email protected]>
> Signed-off-by: Anirudh Ghayal <[email protected]>
> ---
>  drivers/rtc/Kconfig            |    9 +
>  drivers/rtc/Makefile           |    1 +
>  drivers/rtc/rtc-pm8xxx.c       |  567 ++++++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/pm8xxx/rtc.h |   25 ++
>  4 files changed, 602 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/rtc/rtc-pm8xxx.c
>  create mode 100644 include/linux/mfd/pm8xxx/rtc.h
>
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index e187887..a66672a 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -995,4 +995,13 @@ config RTC_DRV_TEGRA
>          This drive can also be built as a module. If so, the module
>          will be called rtc-tegra.
>
> +config RTC_DRV_PM8XXX
> +       tristate "Qualcomm PMIC8XXX RTC"
> +       depends on MFD_PM8XXX
> +       help
> +         Say Y here if you want to support the Qualcomm PMIC8XXX RTC.
> +
> +         To compile this driver as a module, choose M here: the
> +         module will be called rtc-pm8xxx.
> +
>  endif # RTC_CLASS
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index ca91c3c..ff40366 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -72,6 +72,7 @@ obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
>  obj-$(CONFIG_RTC_DRV_PCF8583)  += rtc-pcf8583.o
>  obj-$(CONFIG_RTC_DRV_PCF2123)  += rtc-pcf2123.o
>  obj-$(CONFIG_RTC_DRV_PCF50633) += rtc-pcf50633.o
> +obj-$(CONFIG_RTC_DRV_PM8XXX)    += rtc-pm8xxx.o
>  obj-$(CONFIG_RTC_DRV_PL030)    += rtc-pl030.o
>  obj-$(CONFIG_RTC_DRV_PL031)    += rtc-pl031.o
>  obj-$(CONFIG_RTC_DRV_PS3)      += rtc-ps3.o
> diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
> new file mode 100644
> index 0000000..ce2dad3
> --- /dev/null
> +++ b/drivers/rtc/rtc-pm8xxx.c
> @@ -0,0 +1,567 @@
> +/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * 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.
> + */
> +
> +#define pr_fmt(fmt) "%s: " fmt, __func__
> +

why add pr_fmt here?

> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/rtc.h>
> +#include <linux/pm.h>
> +#include <linux/slab.h>
> +#include<linux/spinlock.h>
> +
> +#include <linux/mfd/pm8xxx/core.h>
> +#include <linux/mfd/pm8xxx/rtc.h>
> +
> +/* RTC Register offsets from RTC CTRL REG */
> +#define PM8XXX_ALARM_CTRL_OFFSET 0x01
> +#define PM8XXX_RTC_WRITE_OFFSET 0x02
> +#define PM8XXX_RTC_READ_OFFSET 0x06
> +#define PM8XXX_ALARM_RW_OFFSET 0x0A
> +
> +/* RTC_CTRL register bit fields */
> +#define PM8xxx_RTC_ENABLE      BIT(7)
> +#define PM8xxx_RTC_ALARM_ENABLE        BIT(1)
> +#define PM8xxx_RTC_ALARM_CLEAR  BIT(0)
> +
> +#define NUM_8_BIT_RTC_REGS     0x4
> +
> +/**
> + * struct pm8xxx_rtc - rtc driver internal structure
> + * @rtc: rtc device for this driver
> + * @rtc_alarm_irq: rtc alarm irq number
> + */
> +struct pm8xxx_rtc {
> +       struct rtc_device *rtc;
> +       int rtc_alarm_irq;
> +       int rtc_base;
> +       int rtc_read_base;
> +       int rtc_write_base;
> +       int alarm_rw_base;
> +       u8  ctrl_reg;
> +       struct device *parent;
> +       spinlock_t ctrl_reg_lock;
> +};
> +
> +/*
> + * The RTC registers need to be read/written one byte at a time. This is a
> + * hardware limitation.
> + */
> +static int pm8xxx_read_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
> +                       int base, int count)
> +{
> +       int i, rc;
> +
> +       for (i = 0; i < count; i++) {
> +               rc = pm8xxx_readb(rtc_dd->parent, base + i, &rtc_val[i]);
> +               if (rc < 0) {
> +                       pr_err("PM8xxx read failed\n");

All pr_err are not so good, please try to use dev_err.

> +                       return rc;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +static int pm8xxx_write_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
> +                       int base, int count)
> +{
> +       int i, rc;
> +
> +       for (i = 0; i < count; i++) {
> +               rc = pm8xxx_writeb(rtc_dd->parent, base + i, rtc_val[i]);
> +               if (rc < 0) {
> +                       pr_err("PM8xxx write failed\n");
> +                       return rc;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +
> +/*
> + * Steps to write the RTC registers.
> + * 1. Disable alarm if enabled.
> + * 2. Write 0x00 to LSB.
> + * 3. Write Byte[1], Byte[2], Byte[3] then Byte[0].
> + * 4. Enable alarm if disabled in step 1.
> + */
> +static int
> +pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
> +{
> +       int rc;
> +       unsigned long secs, irq_flags;
> +       u8 value[4], reg = 0, alarm_enabled = 0, ctrl_reg;
> +       struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
> +
> +       rtc_tm_to_time(tm, &secs);
> +
> +       value[0] = secs & 0xFF;
> +       value[1] = (secs >> 8) & 0xFF;
> +       value[2] = (secs >> 16) & 0xFF;
> +       value[3] = (secs >> 24) & 0xFF;
> +
> +       dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs);
> +
> +       spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
> +       ctrl_reg = rtc_dd->ctrl_reg;
> +
> +       if (ctrl_reg & PM8xxx_RTC_ALARM_ENABLE) {
> +               alarm_enabled = 1;
> +               ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
> +               rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
> +                                                                       1);
> +               if (rc < 0) {
> +                       dev_err(dev, "PM8xxx write failed\n");
> +                       goto rtc_rw_fail;
> +               }
> +       } else
> +               spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
> +
> +       /* Write Byte[1], Byte[2], Byte[3], Byte[0] */
> +       /* Write 0 to Byte[0] */
> +       reg = 0;
> +       rc = pm8xxx_write_wrapper(rtc_dd, &reg, rtc_dd->rtc_write_base, 1);
> +       if (rc < 0) {
> +               dev_err(dev, "PM8xxx write failed\n");
> +               goto rtc_rw_fail;
> +       }
> +
> +       /* Write Byte[1], Byte[2], Byte[3] */
> +       rc = pm8xxx_write_wrapper(rtc_dd, value + 1,
> +                                       rtc_dd->rtc_write_base + 1, 3);
> +       if (rc < 0) {
> +               dev_err(dev, "Write to RTC registers failed\n");
> +               goto rtc_rw_fail;
> +       }
> +
> +       /* Write Byte[0] */
> +       rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->rtc_write_base, 1);
> +       if (rc < 0) {
> +               dev_err(dev, "Write to RTC register failed\n");
> +               goto rtc_rw_fail;
> +       }
> +
> +       if (alarm_enabled) {
> +               ctrl_reg |= PM8xxx_RTC_ALARM_ENABLE;
> +               rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
> +                                                                       1);
> +               if (rc < 0) {
> +                       dev_err(dev, "PM8xxx write failed\n");
> +                       goto rtc_rw_fail;
> +               }
> +       }
> +
> +       rtc_dd->ctrl_reg = ctrl_reg;
> +
> +rtc_rw_fail:
> +       if (alarm_enabled)
> +               spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
> +
> +       return rc;
> +}
> +
> +static int
> +pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
> +{
> +       int rc;
> +       u8 value[4], reg;
> +       unsigned long secs;
> +       struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
> +
> +       rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->rtc_read_base,
> +                                                       NUM_8_BIT_RTC_REGS);
> +       if (rc < 0) {
> +               dev_err(dev, "RTC time read failed\n");
> +               return rc;
> +       }
> +
> +       /*
> +        * Read the LSB again and check if there has been a carry over.
> +        * If there is, redo the read operation.
> +        */
> +       rc = pm8xxx_read_wrapper(rtc_dd, &reg, rtc_dd->rtc_read_base, 1);
> +       if (rc < 0) {
> +               dev_err(dev, "PM8xxx read failed\n");
> +               return rc;
> +       }
> +
> +       if (unlikely(reg < value[0])) {
> +               rc = pm8xxx_read_wrapper(rtc_dd, value,
> +                               rtc_dd->rtc_read_base, NUM_8_BIT_RTC_REGS);
> +               if (rc < 0) {
> +                       dev_err(dev, "RTC time read failed\n");
> +                       return rc;
> +               }
> +       }
> +
> +       secs = value[0] | (value[1] << 8) | (value[2] << 16) \
> +                                               | (value[3] << 24);
> +
> +       rtc_time_to_tm(secs, tm);
> +
> +       rc = rtc_valid_tm(tm);
> +       if (rc < 0) {
> +               dev_err(dev, "Invalid time read from PM8xxx\n");
> +               return rc;
> +       }
> +
> +       dev_dbg(dev, "secs = %lu, h:m:s == %d:%d:%d, d/m/y = %d/%d/%d\n",
> +                       secs, tm->tm_hour, tm->tm_min, tm->tm_sec,
> +                       tm->tm_mday, tm->tm_mon, tm->tm_year);
> +
> +       return 0;
> +}
> +
> +static int
> +pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
> +{
> +       int rc;
> +       u8 value[4], ctrl_reg;
> +       unsigned long secs, secs_rtc, irq_flags;
> +       struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
> +       struct rtc_time rtc_tm;
> +
> +       rtc_tm_to_time(&alarm->time, &secs);
> +
> +       /*
> +        * Read the current RTC time and verify if the alarm time is in the
> +        * past. If yes, return invalid.
> +        */
> +       rc = pm8xxx_rtc_read_time(dev, &rtc_tm);
> +       if (rc < 0) {
> +               dev_err(dev, "Unamble to read RTC time\n");
> +               return -EINVAL;
> +       }
> +
> +       rtc_tm_to_time(&rtc_tm, &secs_rtc);
> +       if (secs < secs_rtc) {
> +               dev_err(dev, "Trying to set alarm in the past\n");
> +               return -EINVAL;
> +       }
> +
> +       value[0] = secs & 0xFF;
> +       value[1] = (secs >> 8) & 0xFF;
> +       value[2] = (secs >> 16) & 0xFF;
> +       value[3] = (secs >> 24) & 0xFF;
> +
> +       spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
> +
> +       rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
> +                                                       NUM_8_BIT_RTC_REGS);
> +       if (rc < 0) {
> +               dev_err(dev, "Write to RTC ALARM registers failed\n");
> +               goto rtc_rw_fail;
> +       }
> +
> +       ctrl_reg = rtc_dd->ctrl_reg;
> +       ctrl_reg = (alarm->enabled) ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
> +                                       (ctrl_reg & ~PM8xxx_RTC_ALARM_ENABLE);
> +
> +       rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
> +       if (rc < 0) {
> +               dev_err(dev, "PM8xxx write failed\n");
> +               goto rtc_rw_fail;
> +       }
> +
> +       rtc_dd->ctrl_reg = ctrl_reg;
> +
> +       dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
> +                       alarm->time.tm_hour, alarm->time.tm_min,
> +                       alarm->time.tm_sec, alarm->time.tm_mday,
> +                       alarm->time.tm_mon, alarm->time.tm_year);
> +rtc_rw_fail:
> +       spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
> +       return rc;
> +}
> +
> +static int
> +pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
> +{
> +       int rc;
> +       u8 value[4];
> +       unsigned long secs;
> +       struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
> +
> +       rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
> +                       NUM_8_BIT_RTC_REGS);
> +       if (rc < 0) {
> +               dev_err(dev, "RTC alarm time read failed\n");
> +               return rc;
> +       }
> +
> +       secs = value[0] | (value[1] << 8) | (value[2] << 16) | \
> +                                                (value[3] << 24);
> +
> +       rtc_time_to_tm(secs, &alarm->time);
> +
> +       rc = rtc_valid_tm(&alarm->time);
> +       if (rc < 0) {
> +               dev_err(dev, "Invalid time read from PM8xxx\n");
> +               return rc;
> +       }
> +
> +       dev_dbg(dev, "Alarm set for - h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
> +               alarm->time.tm_hour, alarm->time.tm_min,
> +                               alarm->time.tm_sec, alarm->time.tm_mday,
> +                               alarm->time.tm_mon, alarm->time.tm_year);
> +
> +       return 0;
> +}
> +
> +
> +static int
> +pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
> +{
> +       int rc;
> +       unsigned long irq_flags;
> +       struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
> +       u8 ctrl_reg;
> +
> +       spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
> +       ctrl_reg = rtc_dd->ctrl_reg;
> +       ctrl_reg = (enabled) ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
> +                               (ctrl_reg & ~PM8xxx_RTC_ALARM_ENABLE);
> +
> +       rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
> +       if (rc < 0) {
> +               dev_err(dev, "PM8xxx write failed\n");
> +               goto rtc_rw_fail;
> +       }
> +
> +       rtc_dd->ctrl_reg = ctrl_reg;
> +
> +rtc_rw_fail:
> +       spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
> +       return rc;
> +}
> +
> +static struct rtc_class_ops pm8xxx_rtc_ops = {
> +       .read_time      = pm8xxx_rtc_read_time,
> +       .set_alarm      = pm8xxx_rtc_set_alarm,
> +       .read_alarm     = pm8xxx_rtc_read_alarm,
> +       .alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
> +};
> +
> +static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
> +{
> +       struct pm8xxx_rtc *rtc_dd = dev_id;
> +       u8 ctrl_reg;
> +       int rc;
> +       unsigned long irq_flags;
> +
> +       rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
> +
> +       spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
> +
> +       /* Clear the alarm enable bit */
> +       ctrl_reg = rtc_dd->ctrl_reg;
> +       ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
> +
> +       rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
> +       if (rc < 0) {
> +               spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
> +               pr_err("PM8xxx write failed!\n");
> +               goto rtc_alarm_handled;
> +       }
> +
> +       rtc_dd->ctrl_reg = ctrl_reg;
> +       spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
> +
> +       /* Clear RTC alarm register */
> +       rc = pm8xxx_read_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base +
> +                                               PM8XXX_ALARM_CTRL_OFFSET, 1);
> +       if (rc < 0) {
> +               pr_err("PM8xxx write failed!\n");
> +               goto rtc_alarm_handled;
> +       }
> +
> +       ctrl_reg &= ~PM8xxx_RTC_ALARM_CLEAR;
> +       rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base +
> +                                               PM8XXX_ALARM_CTRL_OFFSET, 1);
> +       if (rc < 0)
> +               pr_err("PM8xxx write failed!\n");
> +
> +rtc_alarm_handled:
> +       return IRQ_HANDLED;
> +}
> +
> +static int __devinit pm8xxx_rtc_probe(struct platform_device *pdev)
> +{
> +       int rc;
> +       u8 ctrl_reg;
> +       bool rtc_write_enable = false;
> +       struct pm8xxx_rtc *rtc_dd;
> +       struct resource *rtc_resource;
> +       const struct pm8xxx_rtc_platform_data *pdata =
> +               pdev->dev.platform_data;
> +
> +       if (pdata != NULL)
> +               rtc_write_enable = pdata->rtc_write_enable;
> +
> +       rtc_dd = kzalloc(sizeof(*rtc_dd), GFP_KERNEL);
> +       if (rtc_dd == NULL) {
> +               dev_err(&pdev->dev, "Unable to allocate memory!\n");
> +               return -ENOMEM;
> +       }
> +
> +       /* Initialise spinlock to protect RTC cntrol register */
> +       spin_lock_init(&rtc_dd->ctrl_reg_lock);
> +
> +       rtc_dd->rtc_alarm_irq = platform_get_irq(pdev, 0);
> +       if (!rtc_dd->rtc_alarm_irq) {
> +               dev_err(&pdev->dev, "Alarm IRQ resource absent!\n");
> +               rc = -ENXIO;
> +               goto fail_rtc_enable;
> +       }
> +

In fact, the 'platform_get_irq' maybe return -ENXIO, so you should use
the 'if (rtc_dd->rtc_alarm_irq < 0)' instead of '!' to judge
the get irq action.

> +       rtc_resource = platform_get_resource_byname(pdev, IORESOURCE_IO,
> +                                                       "pmic_rtc_base");
> +       if (rtc_resource)
> +               rtc_dd->rtc_base = rtc_resource->start;
> +       if (!rtc_dd->rtc_base) {
> +               dev_err(&pdev->dev, "RTC IO resource absent!\n");
> +               rc = -ENXIO;
> +               goto fail_rtc_enable;
> +       }


rtc_resource = platform_get_resource_byname(pdev, IORESOURCE_IO,
"pmic_rtc_base");
if !(rtc_resource && rtc_resource->start) {
dev_err(&pdev->dev, "RTC IO resource absent!\n");
rc = -ENXIO;
goto fail_rtc_enable;
}
rtc_dd->rtc_base = rtc_resource->start;

Do you think above code style is better?

> +
> +       /* Setup RTC register addresses */
> +       rtc_dd->rtc_write_base = rtc_dd->rtc_base + PM8XXX_RTC_WRITE_OFFSET;
> +       rtc_dd->rtc_read_base = rtc_dd->rtc_base + PM8XXX_RTC_READ_OFFSET;
> +       rtc_dd->alarm_rw_base = rtc_dd->rtc_base + PM8XXX_ALARM_RW_OFFSET;
> +
> +       rtc_dd->parent = pdev->dev.parent;
> +
> +       /* Check if the RTC is on, else turn it on */
> +       rc = pm8xxx_read_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
> +       if (rc < 0) {
> +               dev_err(&pdev->dev, "PM8xxx read failed!\n");
> +               goto fail_rtc_enable;
> +       }
> +
> +       if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) {
> +               ctrl_reg |= PM8xxx_RTC_ENABLE;
> +               rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
> +                                                                       1);
> +               if (rc < 0) {
> +                       dev_err(&pdev->dev, "PM8xxx write failed!\n");
> +                       goto fail_rtc_enable;
> +               }
> +       }
> +
> +       rtc_dd->ctrl_reg = ctrl_reg;
> +       if (rtc_write_enable == true)
> +               pm8xxx_rtc_ops.set_time = pm8xxx_rtc_set_time,
> +
> +       platform_set_drvdata(pdev, rtc_dd);
> +
> +       /* Register the RTC device */
> +       rtc_dd->rtc = rtc_device_register("pm8xxx_rtc", &pdev->dev,
> +                               &pm8xxx_rtc_ops, THIS_MODULE);
> +       if (IS_ERR(rtc_dd->rtc)) {
> +               dev_err(&pdev->dev, "%s: RTC registration failed (%ld)\n",
> +                                       __func__, PTR_ERR(rtc_dd->rtc));
> +               rc = PTR_ERR(rtc_dd->rtc);
> +               goto fail_rtc_enable;
> +       }
> +
> +       /* Request the alarm IRQ */
> +       rc = request_any_context_irq(rtc_dd->rtc_alarm_irq,
> +                                pm8xxx_alarm_trigger, IRQF_TRIGGER_RISING,
> +                                "pm8xxx_rtc_alarm", rtc_dd);
> +       if (rc < 0) {
> +               dev_err(&pdev->dev, "Request IRQ failed (%d)\n", rc);
> +               goto fail_req_irq;
> +       }
> +
> +       device_init_wakeup(&pdev->dev, 1);
> +
> +       dev_dbg(&pdev->dev, "Probe success !!\n");
> +
> +       return 0;
> +
> +fail_req_irq:
> +       rtc_device_unregister(rtc_dd->rtc);
> +fail_rtc_enable:
> +       platform_set_drvdata(pdev, NULL);
> +       kfree(rtc_dd);
> +       return rc;
> +}
> +
> +#ifdef CONFIG_PM
> +static int pm8xxx_rtc_resume(struct device *dev)
> +{
> +       struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
> +
> +       if (device_may_wakeup(dev))
> +               disable_irq_wake(rtc_dd->rtc_alarm_irq);
> +
> +       return 0;
> +}
> +
> +static int pm8xxx_rtc_suspend(struct device *dev)
> +{
> +       struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
> +
> +       if (device_may_wakeup(dev))
> +               enable_irq_wake(rtc_dd->rtc_alarm_irq);
> +
> +       return 0;
> +}
> +
> +static const struct dev_pm_ops pm8xxx_rtc_pm_ops = {
> +       .suspend = pm8xxx_rtc_suspend,
> +       .resume = pm8xxx_rtc_resume,
> +};
> +#endif
> +static int __devexit pm8xxx_rtc_remove(struct platform_device *pdev)
> +{
> +       struct pm8xxx_rtc *rtc_dd = platform_get_drvdata(pdev);
> +
> +       device_init_wakeup(&pdev->dev, 0);
> +       free_irq(rtc_dd->rtc_alarm_irq, rtc_dd);
> +       rtc_device_unregister(rtc_dd->rtc);
> +       platform_set_drvdata(pdev, NULL);
> +       kfree(rtc_dd);
> +
> +       return 0;
> +}
> +
> +static struct platform_driver pm8xxx_rtc_driver = {
> +       .probe          = pm8xxx_rtc_probe,
> +       .remove         = __devexit_p(pm8xxx_rtc_remove),
> +       .driver = {
> +               .name   = PM8XXX_RTC_DEV_NAME,
> +               .owner  = THIS_MODULE,
> +#ifdef CONFIG_PM
> +               .pm     = &pm8xxx_rtc_pm_ops,
> +#endif
> +       },
> +};
> +
> +static int __init pm8xxx_rtc_init(void)
> +{
> +       return platform_driver_register(&pm8xxx_rtc_driver);
> +}
> +module_init(pm8xxx_rtc_init);
> +
> +static void __exit pm8xxx_rtc_exit(void)
> +{
> +       platform_driver_unregister(&pm8xxx_rtc_driver);
> +}
> +module_exit(pm8xxx_rtc_exit);
> +
> +MODULE_ALIAS("platform:rtc-pm8xxx");
> +MODULE_DESCRIPTION("PMIC8xxx RTC driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Anirudh Ghayal <[email protected]>");
> diff --git a/include/linux/mfd/pm8xxx/rtc.h b/include/linux/mfd/pm8xxx/rtc.h
> new file mode 100644
> index 0000000..2528e1d
> --- /dev/null
> +++ b/include/linux/mfd/pm8xxx/rtc.h
> @@ -0,0 +1,25 @@
> +/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * 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.
> + */
> +
> +#ifndef __RTC_PM8XXX_H__
> +#define __RTC_PM8XXX_H__
> +
> +#define PM8XXX_RTC_DEV_NAME     "rtc-pm8xxx"
> +/**
> + * struct pm8058_rtc_pdata - RTC driver platform data
> + * @rtc_write_enable: variable stating RTC write capability
> + */
> +struct pm8xxx_rtc_platform_data {
> +       bool rtc_write_enable;
> +};
> +
> +#endif /* __RTC_PM8XXX_H__ */
> --
> 1.7.3.5
>
> --
> You received this message because you are subscribed to "rtc-linux".
> Membership options at http://groups.google.com/group/rtc-linux .
> Please read http://groups.google.com/group/rtc-linux/web/checklist
> before submitting a driver.



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2011-04-01 08:49:40

by Anirudh Ghayal

[permalink] [raw]
Subject: Re: [rtc-linux] [PATCH 3/3] drivers: rtc: Add support for Qualcomm PMIC8xxx RTC

Hi Wan,

Thank you for reviewing this. I will submit a V2 patch with the changes.

On 3/31/2011 10:18 PM, Wan ZongShun wrote:
> Hi Anirudh,
>
> Some advice below:
>
> 2011/3/27 Anirudh Ghayal<[email protected]>:
>> PMIC8xxx is Qualcomm's power management IC. A
>> 32-bit RTC is housed inside this PMIC. The RTC driver
>> uses SSBI to communicate with the RTC module.
>>
>> Cc: Alessandro Zummo<[email protected]>
>> Cc: Lars-Peter Clausen<[email protected]>
>> Signed-off-by: Anirudh Ghayal<[email protected]>
>> ---
>> drivers/rtc/Kconfig | 9 +
>> drivers/rtc/Makefile | 1 +
>> drivers/rtc/rtc-pm8xxx.c | 567 ++++++++++++++++++++++++++++++++++++++++
>> include/linux/mfd/pm8xxx/rtc.h | 25 ++
>> 4 files changed, 602 insertions(+), 0 deletions(-)
>> create mode 100644 drivers/rtc/rtc-pm8xxx.c
>> create mode 100644 include/linux/mfd/pm8xxx/rtc.h
>>
>> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
>> index e187887..a66672a 100644
>> --- a/drivers/rtc/Kconfig
>> +++ b/drivers/rtc/Kconfig
>> @@ -995,4 +995,13 @@ config RTC_DRV_TEGRA
>> This drive can also be built as a module. If so, the module
>> will be called rtc-tegra.
>>
>> +config RTC_DRV_PM8XXX
>> + tristate "Qualcomm PMIC8XXX RTC"
>> + depends on MFD_PM8XXX
>> + help
>> + Say Y here if you want to support the Qualcomm PMIC8XXX RTC.
>> +
>> + To compile this driver as a module, choose M here: the
>> + module will be called rtc-pm8xxx.
>> +
>> endif # RTC_CLASS
>> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
>> index ca91c3c..ff40366 100644
>> --- a/drivers/rtc/Makefile
>> +++ b/drivers/rtc/Makefile
>> @@ -72,6 +72,7 @@ obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
>> obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o
>> obj-$(CONFIG_RTC_DRV_PCF2123) += rtc-pcf2123.o
>> obj-$(CONFIG_RTC_DRV_PCF50633) += rtc-pcf50633.o
>> +obj-$(CONFIG_RTC_DRV_PM8XXX) += rtc-pm8xxx.o
>> obj-$(CONFIG_RTC_DRV_PL030) += rtc-pl030.o
>> obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o
>> obj-$(CONFIG_RTC_DRV_PS3) += rtc-ps3.o
>> diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
>> new file mode 100644
>> index 0000000..ce2dad3
>> --- /dev/null
>> +++ b/drivers/rtc/rtc-pm8xxx.c
>> @@ -0,0 +1,567 @@
>> +/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 and
>> + * only version 2 as published by the Free Software Foundation.
>> + *
>> + * 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.
>> + */
>> +
>> +#define pr_fmt(fmt) "%s: " fmt, __func__
>> +
>
> why add pr_fmt here?
Will not need this after I move to dev_* calls.
>
>> +#include<linux/module.h>
>> +#include<linux/init.h>
>> +#include<linux/rtc.h>
>> +#include<linux/pm.h>
>> +#include<linux/slab.h>
>> +#include<linux/spinlock.h>
>> +
>> +#include<linux/mfd/pm8xxx/core.h>
>> +#include<linux/mfd/pm8xxx/rtc.h>
>> +
>> +/* RTC Register offsets from RTC CTRL REG */
>> +#define PM8XXX_ALARM_CTRL_OFFSET 0x01
>> +#define PM8XXX_RTC_WRITE_OFFSET 0x02
>> +#define PM8XXX_RTC_READ_OFFSET 0x06
>> +#define PM8XXX_ALARM_RW_OFFSET 0x0A
>> +
>> +/* RTC_CTRL register bit fields */
>> +#define PM8xxx_RTC_ENABLE BIT(7)
>> +#define PM8xxx_RTC_ALARM_ENABLE BIT(1)
>> +#define PM8xxx_RTC_ALARM_CLEAR BIT(0)
>> +
>> +#define NUM_8_BIT_RTC_REGS 0x4
>> +
>> +/**
>> + * struct pm8xxx_rtc - rtc driver internal structure
>> + * @rtc: rtc device for this driver
>> + * @rtc_alarm_irq: rtc alarm irq number
>> + */
>> +struct pm8xxx_rtc {
>> + struct rtc_device *rtc;
>> + int rtc_alarm_irq;
>> + int rtc_base;
>> + int rtc_read_base;
>> + int rtc_write_base;
>> + int alarm_rw_base;
>> + u8 ctrl_reg;
>> + struct device *parent;
>> + spinlock_t ctrl_reg_lock;
>> +};
>> +
>> +/*
>> + * The RTC registers need to be read/written one byte at a time. This is a
>> + * hardware limitation.
>> + */
>> +static int pm8xxx_read_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
>> + int base, int count)
>> +{
>> + int i, rc;
>> +
>> + for (i = 0; i< count; i++) {
>> + rc = pm8xxx_readb(rtc_dd->parent, base + i,&rtc_val[i]);
>> + if (rc< 0) {
>> + pr_err("PM8xxx read failed\n");
>
> All pr_err are not so good, please try to use dev_err.

Ok.

>
>> + return rc;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int pm8xxx_write_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
>> + int base, int count)
>> +{
>> + int i, rc;
>> +
>> + for (i = 0; i< count; i++) {
>> + rc = pm8xxx_writeb(rtc_dd->parent, base + i, rtc_val[i]);
>> + if (rc< 0) {
>> + pr_err("PM8xxx write failed\n");
>> + return rc;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +
>> +/*
>> + * Steps to write the RTC registers.
>> + * 1. Disable alarm if enabled.
>> + * 2. Write 0x00 to LSB.
>> + * 3. Write Byte[1], Byte[2], Byte[3] then Byte[0].
>> + * 4. Enable alarm if disabled in step 1.
>> + */
>> +static int
>> +pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
>> +{
>> + int rc;
>> + unsigned long secs, irq_flags;
>> + u8 value[4], reg = 0, alarm_enabled = 0, ctrl_reg;
>> + struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
>> +
>> + rtc_tm_to_time(tm,&secs);
>> +
>> + value[0] = secs& 0xFF;
>> + value[1] = (secs>> 8)& 0xFF;
>> + value[2] = (secs>> 16)& 0xFF;
>> + value[3] = (secs>> 24)& 0xFF;
>> +
>> + dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs);
>> +
>> + spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
>> + ctrl_reg = rtc_dd->ctrl_reg;
>> +
>> + if (ctrl_reg& PM8xxx_RTC_ALARM_ENABLE) {
>> + alarm_enabled = 1;
>> + ctrl_reg&= ~PM8xxx_RTC_ALARM_ENABLE;
>> + rc = pm8xxx_write_wrapper(rtc_dd,&ctrl_reg, rtc_dd->rtc_base,
>> + 1);
>> + if (rc< 0) {
>> + dev_err(dev, "PM8xxx write failed\n");
>> + goto rtc_rw_fail;
>> + }
>> + } else
>> + spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
>> +
>> + /* Write Byte[1], Byte[2], Byte[3], Byte[0] */
>> + /* Write 0 to Byte[0] */
>> + reg = 0;
>> + rc = pm8xxx_write_wrapper(rtc_dd,&reg, rtc_dd->rtc_write_base, 1);
>> + if (rc< 0) {
>> + dev_err(dev, "PM8xxx write failed\n");
>> + goto rtc_rw_fail;
>> + }
>> +
>> + /* Write Byte[1], Byte[2], Byte[3] */
>> + rc = pm8xxx_write_wrapper(rtc_dd, value + 1,
>> + rtc_dd->rtc_write_base + 1, 3);
>> + if (rc< 0) {
>> + dev_err(dev, "Write to RTC registers failed\n");
>> + goto rtc_rw_fail;
>> + }
>> +
>> + /* Write Byte[0] */
>> + rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->rtc_write_base, 1);
>> + if (rc< 0) {
>> + dev_err(dev, "Write to RTC register failed\n");
>> + goto rtc_rw_fail;
>> + }
>> +
>> + if (alarm_enabled) {
>> + ctrl_reg |= PM8xxx_RTC_ALARM_ENABLE;
>> + rc = pm8xxx_write_wrapper(rtc_dd,&ctrl_reg, rtc_dd->rtc_base,
>> + 1);
>> + if (rc< 0) {
>> + dev_err(dev, "PM8xxx write failed\n");
>> + goto rtc_rw_fail;
>> + }
>> + }
>> +
>> + rtc_dd->ctrl_reg = ctrl_reg;
>> +
>> +rtc_rw_fail:
>> + if (alarm_enabled)
>> + spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
>> +
>> + return rc;
>> +}
>> +
>> +static int
>> +pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
>> +{
>> + int rc;
>> + u8 value[4], reg;
>> + unsigned long secs;
>> + struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
>> +
>> + rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->rtc_read_base,
>> + NUM_8_BIT_RTC_REGS);
>> + if (rc< 0) {
>> + dev_err(dev, "RTC time read failed\n");
>> + return rc;
>> + }
>> +
>> + /*
>> + * Read the LSB again and check if there has been a carry over.
>> + * If there is, redo the read operation.
>> + */
>> + rc = pm8xxx_read_wrapper(rtc_dd,&reg, rtc_dd->rtc_read_base, 1);
>> + if (rc< 0) {
>> + dev_err(dev, "PM8xxx read failed\n");
>> + return rc;
>> + }
>> +
>> + if (unlikely(reg< value[0])) {
>> + rc = pm8xxx_read_wrapper(rtc_dd, value,
>> + rtc_dd->rtc_read_base, NUM_8_BIT_RTC_REGS);
>> + if (rc< 0) {
>> + dev_err(dev, "RTC time read failed\n");
>> + return rc;
>> + }
>> + }
>> +
>> + secs = value[0] | (value[1]<< 8) | (value[2]<< 16) \
>> + | (value[3]<< 24);
>> +
>> + rtc_time_to_tm(secs, tm);
>> +
>> + rc = rtc_valid_tm(tm);
>> + if (rc< 0) {
>> + dev_err(dev, "Invalid time read from PM8xxx\n");
>> + return rc;
>> + }
>> +
>> + dev_dbg(dev, "secs = %lu, h:m:s == %d:%d:%d, d/m/y = %d/%d/%d\n",
>> + secs, tm->tm_hour, tm->tm_min, tm->tm_sec,
>> + tm->tm_mday, tm->tm_mon, tm->tm_year);
>> +
>> + return 0;
>> +}
>> +
>> +static int
>> +pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
>> +{
>> + int rc;
>> + u8 value[4], ctrl_reg;
>> + unsigned long secs, secs_rtc, irq_flags;
>> + struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
>> + struct rtc_time rtc_tm;
>> +
>> + rtc_tm_to_time(&alarm->time,&secs);
>> +
>> + /*
>> + * Read the current RTC time and verify if the alarm time is in the
>> + * past. If yes, return invalid.
>> + */
>> + rc = pm8xxx_rtc_read_time(dev,&rtc_tm);
>> + if (rc< 0) {
>> + dev_err(dev, "Unamble to read RTC time\n");
>> + return -EINVAL;
>> + }
>> +
>> + rtc_tm_to_time(&rtc_tm,&secs_rtc);
>> + if (secs< secs_rtc) {
>> + dev_err(dev, "Trying to set alarm in the past\n");
>> + return -EINVAL;
>> + }
>> +
>> + value[0] = secs& 0xFF;
>> + value[1] = (secs>> 8)& 0xFF;
>> + value[2] = (secs>> 16)& 0xFF;
>> + value[3] = (secs>> 24)& 0xFF;
>> +
>> + spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
>> +
>> + rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
>> + NUM_8_BIT_RTC_REGS);
>> + if (rc< 0) {
>> + dev_err(dev, "Write to RTC ALARM registers failed\n");
>> + goto rtc_rw_fail;
>> + }
>> +
>> + ctrl_reg = rtc_dd->ctrl_reg;
>> + ctrl_reg = (alarm->enabled) ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
>> + (ctrl_reg& ~PM8xxx_RTC_ALARM_ENABLE);
>> +
>> + rc = pm8xxx_write_wrapper(rtc_dd,&ctrl_reg, rtc_dd->rtc_base, 1);
>> + if (rc< 0) {
>> + dev_err(dev, "PM8xxx write failed\n");
>> + goto rtc_rw_fail;
>> + }
>> +
>> + rtc_dd->ctrl_reg = ctrl_reg;
>> +
>> + dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
>> + alarm->time.tm_hour, alarm->time.tm_min,
>> + alarm->time.tm_sec, alarm->time.tm_mday,
>> + alarm->time.tm_mon, alarm->time.tm_year);
>> +rtc_rw_fail:
>> + spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
>> + return rc;
>> +}
>> +
>> +static int
>> +pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
>> +{
>> + int rc;
>> + u8 value[4];
>> + unsigned long secs;
>> + struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
>> +
>> + rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
>> + NUM_8_BIT_RTC_REGS);
>> + if (rc< 0) {
>> + dev_err(dev, "RTC alarm time read failed\n");
>> + return rc;
>> + }
>> +
>> + secs = value[0] | (value[1]<< 8) | (value[2]<< 16) | \
>> + (value[3]<< 24);
>> +
>> + rtc_time_to_tm(secs,&alarm->time);
>> +
>> + rc = rtc_valid_tm(&alarm->time);
>> + if (rc< 0) {
>> + dev_err(dev, "Invalid time read from PM8xxx\n");
>> + return rc;
>> + }
>> +
>> + dev_dbg(dev, "Alarm set for - h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
>> + alarm->time.tm_hour, alarm->time.tm_min,
>> + alarm->time.tm_sec, alarm->time.tm_mday,
>> + alarm->time.tm_mon, alarm->time.tm_year);
>> +
>> + return 0;
>> +}
>> +
>> +
>> +static int
>> +pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
>> +{
>> + int rc;
>> + unsigned long irq_flags;
>> + struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
>> + u8 ctrl_reg;
>> +
>> + spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
>> + ctrl_reg = rtc_dd->ctrl_reg;
>> + ctrl_reg = (enabled) ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
>> + (ctrl_reg& ~PM8xxx_RTC_ALARM_ENABLE);
>> +
>> + rc = pm8xxx_write_wrapper(rtc_dd,&ctrl_reg, rtc_dd->rtc_base, 1);
>> + if (rc< 0) {
>> + dev_err(dev, "PM8xxx write failed\n");
>> + goto rtc_rw_fail;
>> + }
>> +
>> + rtc_dd->ctrl_reg = ctrl_reg;
>> +
>> +rtc_rw_fail:
>> + spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
>> + return rc;
>> +}
>> +
>> +static struct rtc_class_ops pm8xxx_rtc_ops = {
>> + .read_time = pm8xxx_rtc_read_time,
>> + .set_alarm = pm8xxx_rtc_set_alarm,
>> + .read_alarm = pm8xxx_rtc_read_alarm,
>> + .alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
>> +};
>> +
>> +static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
>> +{
>> + struct pm8xxx_rtc *rtc_dd = dev_id;
>> + u8 ctrl_reg;
>> + int rc;
>> + unsigned long irq_flags;
>> +
>> + rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
>> +
>> + spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
>> +
>> + /* Clear the alarm enable bit */
>> + ctrl_reg = rtc_dd->ctrl_reg;
>> + ctrl_reg&= ~PM8xxx_RTC_ALARM_ENABLE;
>> +
>> + rc = pm8xxx_write_wrapper(rtc_dd,&ctrl_reg, rtc_dd->rtc_base, 1);
>> + if (rc< 0) {
>> + spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
>> + pr_err("PM8xxx write failed!\n");
>> + goto rtc_alarm_handled;
>> + }
>> +
>> + rtc_dd->ctrl_reg = ctrl_reg;
>> + spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
>> +
>> + /* Clear RTC alarm register */
>> + rc = pm8xxx_read_wrapper(rtc_dd,&ctrl_reg, rtc_dd->rtc_base +
>> + PM8XXX_ALARM_CTRL_OFFSET, 1);
>> + if (rc< 0) {
>> + pr_err("PM8xxx write failed!\n");
>> + goto rtc_alarm_handled;
>> + }
>> +
>> + ctrl_reg&= ~PM8xxx_RTC_ALARM_CLEAR;
>> + rc = pm8xxx_write_wrapper(rtc_dd,&ctrl_reg, rtc_dd->rtc_base +
>> + PM8XXX_ALARM_CTRL_OFFSET, 1);
>> + if (rc< 0)
>> + pr_err("PM8xxx write failed!\n");
>> +
>> +rtc_alarm_handled:
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int __devinit pm8xxx_rtc_probe(struct platform_device *pdev)
>> +{
>> + int rc;
>> + u8 ctrl_reg;
>> + bool rtc_write_enable = false;
>> + struct pm8xxx_rtc *rtc_dd;
>> + struct resource *rtc_resource;
>> + const struct pm8xxx_rtc_platform_data *pdata =
>> + pdev->dev.platform_data;
>> +
>> + if (pdata != NULL)
>> + rtc_write_enable = pdata->rtc_write_enable;
>> +
>> + rtc_dd = kzalloc(sizeof(*rtc_dd), GFP_KERNEL);
>> + if (rtc_dd == NULL) {
>> + dev_err(&pdev->dev, "Unable to allocate memory!\n");
>> + return -ENOMEM;
>> + }
>> +
>> + /* Initialise spinlock to protect RTC cntrol register */
>> + spin_lock_init(&rtc_dd->ctrl_reg_lock);
>> +
>> + rtc_dd->rtc_alarm_irq = platform_get_irq(pdev, 0);
>> + if (!rtc_dd->rtc_alarm_irq) {
>> + dev_err(&pdev->dev, "Alarm IRQ resource absent!\n");
>> + rc = -ENXIO;
>> + goto fail_rtc_enable;
>> + }
>> +
>
> In fact, the 'platform_get_irq' maybe return -ENXIO, so you should use
> the 'if (rtc_dd->rtc_alarm_irq< 0)' instead of '!' to judge
> the get irq action.
>

Right. Thanks for pointing this out. Will correct this in my V2 patch.

>> + rtc_resource = platform_get_resource_byname(pdev, IORESOURCE_IO,
>> + "pmic_rtc_base");
>> + if (rtc_resource)
>> + rtc_dd->rtc_base = rtc_resource->start;
>> + if (!rtc_dd->rtc_base) {
>> + dev_err(&pdev->dev, "RTC IO resource absent!\n");
>> + rc = -ENXIO;
>> + goto fail_rtc_enable;
>> + }
>
>
> rtc_resource = platform_get_resource_byname(pdev, IORESOURCE_IO,
> "pmic_rtc_base");
> if !(rtc_resource&& rtc_resource->start) {
> dev_err(&pdev->dev, "RTC IO resource absent!\n");
> rc = -ENXIO;
> goto fail_rtc_enable;
> }
> rtc_dd->rtc_base = rtc_resource->start;
>
> Do you think above code style is better?
Yes, looks better.

>
>> +
>> + /* Setup RTC register addresses */
>> + rtc_dd->rtc_write_base = rtc_dd->rtc_base + PM8XXX_RTC_WRITE_OFFSET;
>> + rtc_dd->rtc_read_base = rtc_dd->rtc_base + PM8XXX_RTC_READ_OFFSET;
>> + rtc_dd->alarm_rw_base = rtc_dd->rtc_base + PM8XXX_ALARM_RW_OFFSET;
>> +
>> + rtc_dd->parent = pdev->dev.parent;
>> +
>> + /* Check if the RTC is on, else turn it on */
>> + rc = pm8xxx_read_wrapper(rtc_dd,&ctrl_reg, rtc_dd->rtc_base, 1);
>> + if (rc< 0) {
>> + dev_err(&pdev->dev, "PM8xxx read failed!\n");
>> + goto fail_rtc_enable;
>> + }
>> +
>> + if (!(ctrl_reg& PM8xxx_RTC_ENABLE)) {
>> + ctrl_reg |= PM8xxx_RTC_ENABLE;
>> + rc = pm8xxx_write_wrapper(rtc_dd,&ctrl_reg, rtc_dd->rtc_base,
>> + 1);
>> + if (rc< 0) {
>> + dev_err(&pdev->dev, "PM8xxx write failed!\n");
>> + goto fail_rtc_enable;
>> + }
>> + }
>> +
>> + rtc_dd->ctrl_reg = ctrl_reg;
>> + if (rtc_write_enable == true)
>> + pm8xxx_rtc_ops.set_time = pm8xxx_rtc_set_time,
>> +
>> + platform_set_drvdata(pdev, rtc_dd);
>> +
>> + /* Register the RTC device */
>> + rtc_dd->rtc = rtc_device_register("pm8xxx_rtc",&pdev->dev,
>> +&pm8xxx_rtc_ops, THIS_MODULE);
>> + if (IS_ERR(rtc_dd->rtc)) {
>> + dev_err(&pdev->dev, "%s: RTC registration failed (%ld)\n",
>> + __func__, PTR_ERR(rtc_dd->rtc));
>> + rc = PTR_ERR(rtc_dd->rtc);
>> + goto fail_rtc_enable;
>> + }
>> +
>> + /* Request the alarm IRQ */
>> + rc = request_any_context_irq(rtc_dd->rtc_alarm_irq,
>> + pm8xxx_alarm_trigger, IRQF_TRIGGER_RISING,
>> + "pm8xxx_rtc_alarm", rtc_dd);
>> + if (rc< 0) {
>> + dev_err(&pdev->dev, "Request IRQ failed (%d)\n", rc);
>> + goto fail_req_irq;
>> + }
>> +
>> + device_init_wakeup(&pdev->dev, 1);
>> +
>> + dev_dbg(&pdev->dev, "Probe success !!\n");
>> +
>> + return 0;
>> +
>> +fail_req_irq:
>> + rtc_device_unregister(rtc_dd->rtc);
>> +fail_rtc_enable:
>> + platform_set_drvdata(pdev, NULL);
>> + kfree(rtc_dd);
>> + return rc;
>> +}
>> +
>> +#ifdef CONFIG_PM
>> +static int pm8xxx_rtc_resume(struct device *dev)
>> +{
>> + struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
>> +
>> + if (device_may_wakeup(dev))
>> + disable_irq_wake(rtc_dd->rtc_alarm_irq);
>> +
>> + return 0;
>> +}
>> +
>> +static int pm8xxx_rtc_suspend(struct device *dev)
>> +{
>> + struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
>> +
>> + if (device_may_wakeup(dev))
>> + enable_irq_wake(rtc_dd->rtc_alarm_irq);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct dev_pm_ops pm8xxx_rtc_pm_ops = {
>> + .suspend = pm8xxx_rtc_suspend,
>> + .resume = pm8xxx_rtc_resume,
>> +};
>> +#endif
>> +static int __devexit pm8xxx_rtc_remove(struct platform_device *pdev)
>> +{
>> + struct pm8xxx_rtc *rtc_dd = platform_get_drvdata(pdev);
>> +
>> + device_init_wakeup(&pdev->dev, 0);
>> + free_irq(rtc_dd->rtc_alarm_irq, rtc_dd);
>> + rtc_device_unregister(rtc_dd->rtc);
>> + platform_set_drvdata(pdev, NULL);
>> + kfree(rtc_dd);
>> +
>> + return 0;
>> +}
>> +
>> +static struct platform_driver pm8xxx_rtc_driver = {
>> + .probe = pm8xxx_rtc_probe,
>> + .remove = __devexit_p(pm8xxx_rtc_remove),
>> + .driver = {
>> + .name = PM8XXX_RTC_DEV_NAME,
>> + .owner = THIS_MODULE,
>> +#ifdef CONFIG_PM
>> + .pm =&pm8xxx_rtc_pm_ops,
>> +#endif
>> + },
>> +};
>> +
>> +static int __init pm8xxx_rtc_init(void)
>> +{
>> + return platform_driver_register(&pm8xxx_rtc_driver);
>> +}
>> +module_init(pm8xxx_rtc_init);
>> +
>> +static void __exit pm8xxx_rtc_exit(void)
>> +{
>> + platform_driver_unregister(&pm8xxx_rtc_driver);
>> +}
>> +module_exit(pm8xxx_rtc_exit);
>> +
>> +MODULE_ALIAS("platform:rtc-pm8xxx");
>> +MODULE_DESCRIPTION("PMIC8xxx RTC driver");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_AUTHOR("Anirudh Ghayal<[email protected]>");
>> diff --git a/include/linux/mfd/pm8xxx/rtc.h b/include/linux/mfd/pm8xxx/rtc.h
>> new file mode 100644
>> index 0000000..2528e1d
>> --- /dev/null
>> +++ b/include/linux/mfd/pm8xxx/rtc.h
>> @@ -0,0 +1,25 @@
>> +/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 and
>> + * only version 2 as published by the Free Software Foundation.
>> + *
>> + * 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.
>> + */
>> +
>> +#ifndef __RTC_PM8XXX_H__
>> +#define __RTC_PM8XXX_H__
>> +
>> +#define PM8XXX_RTC_DEV_NAME "rtc-pm8xxx"
>> +/**
>> + * struct pm8058_rtc_pdata - RTC driver platform data
>> + * @rtc_write_enable: variable stating RTC write capability
>> + */
>> +struct pm8xxx_rtc_platform_data {
>> + bool rtc_write_enable;
>> +};
>> +
>> +#endif /* __RTC_PM8XXX_H__ */
>> --
>> 1.7.3.5
>>
>> --
>> You received this message because you are subscribed to "rtc-linux".
>> Membership options at http://groups.google.com/group/rtc-linux .
>> Please read http://groups.google.com/group/rtc-linux/web/checklist
>> before submitting a driver.
>
>
>

Thank you,
~Anirudh


--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.