linux/drivers/rtc/rtc-pcf2123.c

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/*
* An SPI driver for the Philips PCF2123 RTC
* Copyright 2009 Cyber Switching, Inc.
*
* Author: Chris Verges <chrisv@cyberswitching.com>
* Maintainers: http://www.cyberswitching.com
*
* based on the RS5C348 driver in this same directory.
*
* Thanks to Christian Pellegrin <chripell@fsfe.org> for
* the sysfs contributions to this driver.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Please note that the CS is active high, so platform data
* should look something like:
*
* static struct spi_board_info ek_spi_devices[] = {
* ...
* {
* .modalias = "rtc-pcf2123",
* .chip_select = 1,
* .controller_data = (void *)AT91_PIN_PA10,
* .max_speed_hz = 1000 * 1000,
* .mode = SPI_CS_HIGH,
* .bus_num = 0,
* },
* ...
*};
*
*/
#include <linux/bcd.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/sysfs.h>
#define DRV_VERSION "0.6"
#define PCF2123_REG_CTRL1 (0x00) /* Control Register 1 */
#define PCF2123_REG_CTRL2 (0x01) /* Control Register 2 */
#define PCF2123_REG_SC (0x02) /* datetime */
#define PCF2123_REG_MN (0x03)
#define PCF2123_REG_HR (0x04)
#define PCF2123_REG_DM (0x05)
#define PCF2123_REG_DW (0x06)
#define PCF2123_REG_MO (0x07)
#define PCF2123_REG_YR (0x08)
#define PCF2123_SUBADDR (1 << 4)
#define PCF2123_WRITE ((0 << 7) | PCF2123_SUBADDR)
#define PCF2123_READ ((1 << 7) | PCF2123_SUBADDR)
static struct spi_driver pcf2123_driver;
struct pcf2123_sysfs_reg {
struct device_attribute attr;
char name[2];
};
struct pcf2123_plat_data {
struct rtc_device *rtc;
struct pcf2123_sysfs_reg regs[16];
};
/*
* Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
* is released properly after an SPI write. This function should be
* called after EVERY read/write call over SPI.
*/
static inline void pcf2123_delay_trec(void)
{
ndelay(30);
}
static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr,
char *buffer)
{
struct spi_device *spi = to_spi_device(dev);
struct pcf2123_sysfs_reg *r;
u8 txbuf[1], rxbuf[1];
unsigned long reg;
int ret;
r = container_of(attr, struct pcf2123_sysfs_reg, attr);
if (strict_strtoul(r->name, 16, &reg))
return -EINVAL;
txbuf[0] = PCF2123_READ | reg;
ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
if (ret < 0)
return -EIO;
pcf2123_delay_trec();
return sprintf(buffer, "0x%x\n", rxbuf[0]);
}
static ssize_t pcf2123_store(struct device *dev, struct device_attribute *attr,
const char *buffer, size_t count) {
struct spi_device *spi = to_spi_device(dev);
struct pcf2123_sysfs_reg *r;
u8 txbuf[2];
unsigned long reg;
unsigned long val;
int ret;
r = container_of(attr, struct pcf2123_sysfs_reg, attr);
if (strict_strtoul(r->name, 16, &reg)
|| strict_strtoul(buffer, 10, &val))
return -EINVAL;
txbuf[0] = PCF2123_WRITE | reg;
txbuf[1] = val;
ret = spi_write(spi, txbuf, sizeof(txbuf));
if (ret < 0)
return -EIO;
pcf2123_delay_trec();
return count;
}
static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct spi_device *spi = to_spi_device(dev);
u8 txbuf[1], rxbuf[7];
int ret;
txbuf[0] = PCF2123_READ | PCF2123_REG_SC;
ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
rxbuf, sizeof(rxbuf));
if (ret < 0)
return ret;
pcf2123_delay_trec();
tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
tm->tm_hour = bcd2bin(rxbuf[2] & 0x3F); /* rtc hr 0-23 */
tm->tm_mday = bcd2bin(rxbuf[3] & 0x3F);
tm->tm_wday = rxbuf[4] & 0x07;
tm->tm_mon = bcd2bin(rxbuf[5] & 0x1F) - 1; /* rtc mn 1-12 */
tm->tm_year = bcd2bin(rxbuf[6]);
if (tm->tm_year < 70)
tm->tm_year += 100; /* assume we are in 1970...2069 */
dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
/* the clock can give out invalid datetime, but we cannot return
* -EINVAL otherwise hwclock will refuse to set the time on bootup.
*/
if (rtc_valid_tm(tm) < 0)
dev_err(dev, "retrieved date/time is not valid.\n");
return 0;
}
static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct spi_device *spi = to_spi_device(dev);
u8 txbuf[8];
int ret;
dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
/* Stop the counter first */
txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
txbuf[1] = 0x20;
ret = spi_write(spi, txbuf, 2);
if (ret < 0)
return ret;
pcf2123_delay_trec();
/* Set the new time */
txbuf[0] = PCF2123_WRITE | PCF2123_REG_SC;
txbuf[1] = bin2bcd(tm->tm_sec & 0x7F);
txbuf[2] = bin2bcd(tm->tm_min & 0x7F);
txbuf[3] = bin2bcd(tm->tm_hour & 0x3F);
txbuf[4] = bin2bcd(tm->tm_mday & 0x3F);
txbuf[5] = tm->tm_wday & 0x07;
txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);
ret = spi_write(spi, txbuf, sizeof(txbuf));
if (ret < 0)
return ret;
pcf2123_delay_trec();
/* Start the counter */
txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
txbuf[1] = 0x00;
ret = spi_write(spi, txbuf, 2);
if (ret < 0)
return ret;
pcf2123_delay_trec();
return 0;
}
static const struct rtc_class_ops pcf2123_rtc_ops = {
.read_time = pcf2123_rtc_read_time,
.set_time = pcf2123_rtc_set_time,
};
static int pcf2123_probe(struct spi_device *spi)
{
struct rtc_device *rtc;
struct pcf2123_plat_data *pdata;
u8 txbuf[2], rxbuf[2];
int ret, i;
pdata = kzalloc(sizeof(struct pcf2123_plat_data), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
spi->dev.platform_data = pdata;
/* Send a software reset command */
txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
txbuf[1] = 0x58;
dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n",
txbuf[0], txbuf[1]);
ret = spi_write(spi, txbuf, 2 * sizeof(u8));
if (ret < 0)
goto kfree_exit;
pcf2123_delay_trec();
/* Stop the counter */
txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
txbuf[1] = 0x20;
dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n",
txbuf[0], txbuf[1]);
ret = spi_write(spi, txbuf, 2 * sizeof(u8));
if (ret < 0)
goto kfree_exit;
pcf2123_delay_trec();
/* See if the counter was actually stopped */
txbuf[0] = PCF2123_READ | PCF2123_REG_CTRL1;
dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n",
txbuf[0]);
ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8),
rxbuf, 2 * sizeof(u8));
dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n",
rxbuf[0], rxbuf[1]);
if (ret < 0)
goto kfree_exit;
pcf2123_delay_trec();
if (!(rxbuf[0] & 0x20)) {
dev_err(&spi->dev, "chip not found\n");
goto kfree_exit;
}
dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
dev_info(&spi->dev, "spiclk %u KHz.\n",
(spi->max_speed_hz + 500) / 1000);
/* Start the counter */
txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
txbuf[1] = 0x00;
ret = spi_write(spi, txbuf, sizeof(txbuf));
if (ret < 0)
goto kfree_exit;
pcf2123_delay_trec();
/* Finalize the initialization */
rtc = rtc_device_register(pcf2123_driver.driver.name, &spi->dev,
&pcf2123_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc)) {
dev_err(&spi->dev, "failed to register.\n");
ret = PTR_ERR(rtc);
goto kfree_exit;
}
pdata->rtc = rtc;
for (i = 0; i < 16; i++) {
sysfs_attr_init(&pdata->regs[i].attr.attr);
sprintf(pdata->regs[i].name, "%1x", i);
pdata->regs[i].attr.attr.mode = S_IRUGO | S_IWUSR;
pdata->regs[i].attr.attr.name = pdata->regs[i].name;
pdata->regs[i].attr.show = pcf2123_show;
pdata->regs[i].attr.store = pcf2123_store;
ret = device_create_file(&spi->dev, &pdata->regs[i].attr);
if (ret) {
dev_err(&spi->dev, "Unable to create sysfs %s\n",
pdata->regs[i].name);
goto sysfs_exit;
}
}
return 0;
sysfs_exit:
for (i--; i >= 0; i--)
device_remove_file(&spi->dev, &pdata->regs[i].attr);
kfree_exit:
kfree(pdata);
spi->dev.platform_data = NULL;
return ret;
}
static int pcf2123_remove(struct spi_device *spi)
{
struct pcf2123_plat_data *pdata = spi->dev.platform_data;
int i;
if (pdata) {
struct rtc_device *rtc = pdata->rtc;
if (rtc)
rtc_device_unregister(rtc);
for (i = 0; i < 16; i++)
if (pdata->regs[i].name[0])
device_remove_file(&spi->dev,
&pdata->regs[i].attr);
kfree(pdata);
}
return 0;
}
static struct spi_driver pcf2123_driver = {
.driver = {
.name = "rtc-pcf2123",
.owner = THIS_MODULE,
},
.probe = pcf2123_probe,
.remove = pcf2123_remove,
};
module_spi_driver(pcf2123_driver);
MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);