From patchwork Mon Jul 5 06:45:30 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zang Roy-R61911 X-Patchwork-Id: 57868 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from bilbo.ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 764C0B7100 for ; Mon, 5 Jul 2010 17:00:21 +1000 (EST) Received: from az33egw02.freescale.net (az33egw02.freescale.net [192.88.158.103]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "az33egw02.freescale.net", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id BD465B6EF7 for ; Mon, 5 Jul 2010 17:00:12 +1000 (EST) Received: from az33smr01.freescale.net (az33smr01.freescale.net [10.64.34.199]) by az33egw02.freescale.net (8.14.3/az33egw02) with ESMTP id o656xx8C002893 for ; Mon, 5 Jul 2010 00:00:09 -0700 (MST) Received: from localhost.localdomain (tank.ap.freescale.net [10.193.20.104]) by az33smr01.freescale.net (8.13.1/8.13.0) with ESMTP id o657AL2f012420; Mon, 5 Jul 2010 02:10:22 -0500 (CDT) From: Roy Zang To: linuxppc-release@linux.freescale.net Subject: [PATCH] rtc: add support for DS3232 RTC Date: Mon, 5 Jul 2010 14:45:30 +0800 Message-Id: <1278312330-19042-1-git-send-email-tie-fei.zang@freescale.com> X-Mailer: git-send-email 1.5.6.5 Cc: Mingkai.hu@freescale.com, linuxppc-dev@lists.ozlabs.org, srikanth.srinivasan@freescale.com X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org This patch adds the driver for RTC chip DS3232 via I2C bus Signed-off-by: Mingkai Hu Signed-off-by: Jingchang Lu Signed-off-by: Srikanth Srinivasan Signed-off-by: Roy Zang --- Tested on MPC8536DS and P4080DS board drivers/rtc/Kconfig | 11 + drivers/rtc/Makefile | 1 + drivers/rtc/rtc-ds3232.c | 466 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 478 insertions(+), 0 deletions(-) create mode 100644 drivers/rtc/rtc-ds3232.c diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 6a13037..13c2fdb 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -166,6 +166,17 @@ config RTC_DRV_DS1672 This driver can also be built as a module. If so, the module will be called rtc-ds1672. +config RTC_DRV_DS3232 + tristate "Dallas/Maxim DS3232" + depends on RTC_CLASS && I2C + help + If you say yes here you get support for Dallas Semiconductor + DS3232 real-time clock chips. If an interrupt is associated + with the device, the alarm functionality is supported. + + This driver can also be built as a module. If so, the module + will be called rtc-ds3232. + config RTC_DRV_MAX6900 tristate "Maxim MAX6900" help diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 44ef194..0af190c 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -39,6 +39,7 @@ obj-$(CONFIG_RTC_DRV_DS1511) += rtc-ds1511.o obj-$(CONFIG_RTC_DRV_DS1553) += rtc-ds1553.o obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o obj-$(CONFIG_RTC_DRV_DS1742) += rtc-ds1742.o +obj-$(CONFIG_RTC_DRV_DS3232) += rtc-ds3232.o obj-$(CONFIG_RTC_DRV_DS3234) += rtc-ds3234.o obj-$(CONFIG_RTC_DRV_EFI) += rtc-efi.o obj-$(CONFIG_RTC_DRV_EP93XX) += rtc-ep93xx.o diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c new file mode 100644 index 0000000..21e1599 --- /dev/null +++ b/drivers/rtc/rtc-ds3232.c @@ -0,0 +1,466 @@ +/* + * RTC client/driver for the Maxim/Dallas DS3232 Real-Time Clock over I2C + * + * Copyright (C) 2009-2010 Freescale Semiconductor. + * + * 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. + */ +/* + * It would be more efficient to use i2c msgs/i2c_transfer directly but, as + * recommened in .../Documentation/i2c/writing-clients section + * "Sending and receiving", using SMBus level communication is preferred. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define DS3232_REG_SECONDS 0x00 +#define DS3232_REG_MINUTES 0x01 +#define DS3232_REG_HOURS 0x02 +#define DS3232_REG_AMPM 0x02 +#define DS3232_REG_DAY 0x03 +#define DS3232_REG_DATE 0x04 +#define DS3232_REG_MONTH 0x05 +#define DS3232_REG_CENTURY 0x05 +#define DS3232_REG_YEAR 0x06 +#define DS3232_REG_ALARM1 0x07 /* Alarm 1 BASE */ +#define DS3232_REG_ALARM2 0x0B /* Alarm 2 BASE */ +#define DS3232_REG_CR 0x0E /* Control register */ +# define DS3232_REG_CR_nEOSC 0x80 +# define DS3232_REG_CR_INTCN 0x04 +# define DS3232_REG_CR_A2IE 0x02 +# define DS3232_REG_CR_A1IE 0x01 + +#define DS3232_REG_SR 0x0F /* control/status register */ +# define DS3232_REG_SR_OSF 0x80 +# define DS3232_REG_SR_BSY 0x04 +# define DS3232_REG_SR_A2F 0x02 +# define DS3232_REG_SR_A1F 0x01 + +struct ds3232 { + struct i2c_client *client; + struct rtc_device *rtc; + struct work_struct work; + + /* The mutex protects alarm operations, and prevents a race + * between the enable_irq() in the workqueue and the free_irq() + * in the remove function. + */ + struct mutex mutex; + int exiting; +}; + +static struct i2c_driver ds3232_driver; + +static int ds3232_check_rtc_status(struct i2c_client *client) +{ + int ret = 0; + int control, stat; + + stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR); + if (stat < 0) + return stat; + + if (stat & DS3232_REG_SR_OSF) + dev_warn(&client->dev, + "oscillator discontinuity flagged, " + "time unreliable\n"); + + stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); + + ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat); + if (ret < 0) + return ret; + + /* If the alarm is pending, clear it before requesting + * the interrupt, so an interrupt event isn't reported + * before everything is initialized. + */ + + control = i2c_smbus_read_byte_data(client, DS3232_REG_CR); + if (control < 0) + return control; + + control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); + control |= DS3232_REG_CR_INTCN; + + return i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); +} + +static int ds3232_read_time(struct device *dev, struct rtc_time *time) +{ + struct i2c_client *client = to_i2c_client(dev); + int ret; + u8 buf[7]; + unsigned int year, month, day, hour, minute, second; + unsigned int week, twelve_hr, am_pm; + unsigned int century, add_century = 0; + + ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_SECONDS, 7, buf); + + if (ret < 0) + return ret; + if (ret < 7) + return -EIO; + + second = buf[0]; + minute = buf[1]; + hour = buf[2]; + week = buf[3]; + day = buf[4]; + month = buf[5]; + year = buf[6]; + + /* Extract additional information for AM/PM and century */ + + twelve_hr = hour & 0x40; + am_pm = hour & 0x20; + century = month & 0x80; + + /* Write to rtc_time structure */ + + time->tm_sec = bcd2bin(second); + time->tm_min = bcd2bin(minute); + if (twelve_hr) { + /* Convert to 24 hr */ + if (am_pm) + time->tm_hour = bcd2bin(hour & 0x1F) + 12; + else + time->tm_hour = bcd2bin(hour & 0x1F); + } else { + time->tm_hour = bcd2bin(hour); + } + + time->tm_wday = bcd2bin(week); + time->tm_mday = bcd2bin(day); + time->tm_mon = bcd2bin(month & 0x7F); + if (century) + add_century = 100; + + time->tm_year = bcd2bin(year) + add_century; + + return 0; +} + +static int ds3232_set_time(struct device *dev, struct rtc_time *time) +{ + struct i2c_client *client = to_i2c_client(dev); + u8 buf[7]; + + /* Extract time from rtc_time and load into ds3232*/ + + buf[0] = bin2bcd(time->tm_sec); + buf[1] = bin2bcd(time->tm_min); + buf[2] = bin2bcd(time->tm_hour); + buf[3] = bin2bcd(time->tm_wday); /* Day of the week */ + buf[4] = bin2bcd(time->tm_mday); /* Date */ + buf[5] = bin2bcd(time->tm_mon); + if (time->tm_year >= 100) { + buf[5] |= 0x80; + buf[6] = bin2bcd(time->tm_year - 100); + } else { + buf[6] = bin2bcd(time->tm_year); + } + + return i2c_smbus_write_i2c_block_data(client, + DS3232_REG_SECONDS, 7, buf); +} + +/* + * DS3232 has two alarm, we only use alarm1 + * According to linux specification, only support one-shot alarm + * no periodic alarm mode + */ +static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ds3232 *ds3232 = i2c_get_clientdata(client); + int control, stat; + int ret = 0; + u8 buf[4]; + + mutex_lock(&ds3232->mutex); + stat = ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR); + if (stat < 0) + goto out; + + control = ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR); + if (control < 0) + goto out; + + ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); + if (ret < 0) + goto out; + + alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F); + alarm->time.tm_min = bcd2bin(buf[1] & 0x7F); + alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F); + alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F); + + alarm->time.tm_mon = -1; + alarm->time.tm_year = -1; + alarm->time.tm_wday = -1; + alarm->time.tm_yday = -1; + alarm->time.tm_isdst = -1; + + alarm->enabled = !!(control & DS3232_REG_CR_A1IE); + alarm->pending = !!(stat & DS3232_REG_SR_A1F); +out: + mutex_unlock(&ds3232->mutex); + + return ret; +} + +/* + * linux rtc-module does not support wday alarm + * and only 24h time mode supported indeed + */ +static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ds3232 *ds3232 = i2c_get_clientdata(client); + int control, stat; + int ret = 0; + u8 buf[4]; + + if (client->irq <= 0) + return -EINVAL; + + mutex_lock(&ds3232->mutex); + + buf[0] = bin2bcd(alarm->time.tm_sec); + buf[1] = bin2bcd(alarm->time.tm_min); + buf[2] = bin2bcd(alarm->time.tm_hour); + buf[3] = bin2bcd(alarm->time.tm_mday); + + /* clear alarm interrupt enable bit */ + ret = control = i2c_smbus_read_byte_data(client, DS3232_REG_CR); + if (ret < 0) + goto out; + control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); + ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); + if (ret < 0) + goto out; + + /* clear any pending alarm flag */ + stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR); + if (stat < 0) + return stat; + + stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); + + ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_i2c_block_data(client, + DS3232_REG_ALARM1, 4, buf); + + if (alarm->enabled) { + control |= DS3232_REG_CR_A1IE; + ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); + } +out: + mutex_unlock(&ds3232->mutex); + return ret; +} + +static irqreturn_t ds3232_irq(int irq, void *dev_id) +{ + struct i2c_client *client = dev_id; + struct ds3232 *ds3232 = i2c_get_clientdata(client); + + disable_irq_nosync(irq); + schedule_work(&ds3232->work); + return IRQ_HANDLED; +} + +static void ds3232_work(struct work_struct *work) +{ + struct ds3232 *ds3232 = container_of(work, struct ds3232, work); + struct i2c_client *client = ds3232->client; + int stat, control; + + mutex_lock(&ds3232->mutex); + + stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR); + if (stat < 0) + goto unlock; + + if (stat & DS3232_REG_SR_A1F) { + control = i2c_smbus_read_byte_data(client, DS3232_REG_CR); + if (control < 0) + goto out; + /* disable alarm1 interrupt */ + control &= ~(DS3232_REG_CR_A1IE); + i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); + + /* clear the alarm pend flag */ + stat &= ~DS3232_REG_SR_A1F; + i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat); + + rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF); + } + +out: + if (!ds3232->exiting) + enable_irq(client->irq); +unlock: + mutex_unlock(&ds3232->mutex); +} + +static int ds3232_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ds3232 *ds3232 = i2c_get_clientdata(client); + int ret = -ENOIOCTLCMD; + + mutex_lock(&ds3232->mutex); + switch (cmd) { + case RTC_AIE_OFF: + ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR); + if (ret < 0) + goto out; + + ret &= ~DS3232_REG_CR_A1IE; + + ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, ret); + if (ret < 0) + goto out; + + break; + + case RTC_AIE_ON: + ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR); + if (ret < 0) + goto out; + + ret |= DS3232_REG_CR_A1IE; + + ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, ret); + if (ret < 0) + goto out; + + break; + } +out: + mutex_unlock(&ds3232->mutex); + + return ret; +} + +static const struct rtc_class_ops ds3232_rtc_ops = { + .read_time = ds3232_read_time, + .set_time = ds3232_set_time, + .read_alarm = ds3232_read_alarm, + .set_alarm = ds3232_set_alarm, + .ioctl = ds3232_ioctl, +}; + +static int ds3232_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct ds3232 *ds3232; + int ret; + + ds3232 = kzalloc(sizeof(struct ds3232), GFP_KERNEL); + if (!ds3232) + return -ENOMEM; + + ds3232->client = client; + i2c_set_clientdata(client, ds3232); + + INIT_WORK(&ds3232->work, ds3232_work); + mutex_init(&ds3232->mutex); + + ret = ds3232_check_rtc_status(client); + if (ret) + goto out_free; + + if (client->irq >= 0) { + ret = request_irq(client->irq, ds3232_irq, 0, + "ds3232", client); + if (ret) + goto out_free; + } + + ds3232->rtc = rtc_device_register(client->name, &client->dev, + &ds3232_rtc_ops, THIS_MODULE); + if (IS_ERR(ds3232->rtc)) { + ret = PTR_ERR(ds3232->rtc); + dev_err(&client->dev, "unable to register the class device\n"); + goto out_irq; + } + + return 0; + +out_irq: + if (client->irq >= 0) + free_irq(client->irq, client); + +out_free: + i2c_set_clientdata(client, NULL); + kfree(ds3232); + return ret; +} + +static int __devexit ds3232_remove(struct i2c_client *client) +{ + struct ds3232 *ds3232 = i2c_get_clientdata(client); + + if (client->irq >= 0) { + mutex_lock(&ds3232->mutex); + ds3232->exiting = 1; + mutex_unlock(&ds3232->mutex); + + free_irq(client->irq, client); + flush_scheduled_work(); + } + + rtc_device_unregister(ds3232->rtc); + i2c_set_clientdata(client, NULL); + kfree(ds3232); + return 0; +} + +static const struct i2c_device_id ds3232_id[] = { + { "ds3232", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ds3232_id); + +static struct i2c_driver ds3232_driver = { + .driver = { + .name = "rtc-ds3232", + .owner = THIS_MODULE, + }, + .probe = ds3232_probe, + .remove = __devexit_p(ds3232_remove), + .id_table = ds3232_id, +}; + +static int __init ds3232_init(void) +{ + return i2c_add_driver(&ds3232_driver); +} + +static void __exit ds3232_exit(void) +{ + i2c_del_driver(&ds3232_driver); +} + +module_init(ds3232_init); +module_exit(ds3232_exit); + +MODULE_AUTHOR("Srikanth Srinivasan "); +MODULE_DESCRIPTION("Maxim/Dallas DS3232 RTC Driver"); +MODULE_LICENSE("GPL");