406 строки
9.0 KiB
C
406 строки
9.0 KiB
C
/*
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* I2C client/driver for the ST M41T00 family of i2c rtc chips.
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*
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* Author: Mark A. Greer <mgreer@mvista.com>
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*
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* 2005, 2006 (c) MontaVista Software, Inc. This file is licensed under
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* the terms of the GNU General Public License version 2. This program
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* is licensed "as is" without any warranty of any kind, whether express
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* or implied.
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*/
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/*
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* This i2c client/driver wedges between the drivers/char/genrtc.c RTC
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* interface and the SMBus interface of the i2c subsystem.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/i2c.h>
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#include <linux/rtc.h>
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#include <linux/bcd.h>
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#include <linux/workqueue.h>
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#include <linux/platform_device.h>
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#include <linux/m41t00.h>
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#include <asm/time.h>
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#include <asm/rtc.h>
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static struct i2c_driver m41t00_driver;
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static struct i2c_client *save_client;
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static unsigned short ignore[] = { I2C_CLIENT_END };
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static unsigned short normal_addr[] = { I2C_CLIENT_END, I2C_CLIENT_END };
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static struct i2c_client_address_data addr_data = {
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.normal_i2c = normal_addr,
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.probe = ignore,
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.ignore = ignore,
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};
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struct m41t00_chip_info {
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u8 type;
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char *name;
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u8 read_limit;
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u8 sec; /* Offsets for chip regs */
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u8 min;
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u8 hour;
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u8 day;
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u8 mon;
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u8 year;
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u8 alarm_mon;
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u8 alarm_hour;
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u8 sqw;
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u8 sqw_freq;
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};
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static struct m41t00_chip_info m41t00_chip_info_tbl[] = {
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{
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.type = M41T00_TYPE_M41T00,
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.name = "m41t00",
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.read_limit = 5,
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.sec = 0,
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.min = 1,
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.hour = 2,
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.day = 4,
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.mon = 5,
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.year = 6,
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},
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{
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.type = M41T00_TYPE_M41T81,
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.name = "m41t81",
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.read_limit = 1,
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.sec = 1,
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.min = 2,
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.hour = 3,
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.day = 5,
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.mon = 6,
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.year = 7,
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.alarm_mon = 0xa,
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.alarm_hour = 0xc,
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.sqw = 0x13,
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},
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{
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.type = M41T00_TYPE_M41T85,
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.name = "m41t85",
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.read_limit = 1,
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.sec = 1,
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.min = 2,
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.hour = 3,
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.day = 5,
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.mon = 6,
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.year = 7,
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.alarm_mon = 0xa,
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.alarm_hour = 0xc,
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.sqw = 0x13,
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},
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};
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static struct m41t00_chip_info *m41t00_chip;
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ulong
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m41t00_get_rtc_time(void)
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{
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s32 sec, min, hour, day, mon, year;
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s32 sec1, min1, hour1, day1, mon1, year1;
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u8 reads = 0;
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u8 buf[8], msgbuf[1] = { 0 }; /* offset into rtc's regs */
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struct i2c_msg msgs[] = {
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{
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.addr = save_client->addr,
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.flags = 0,
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.len = 1,
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.buf = msgbuf,
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},
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{
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.addr = save_client->addr,
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.flags = I2C_M_RD,
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.len = 8,
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.buf = buf,
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},
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};
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sec = min = hour = day = mon = year = 0;
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do {
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if (i2c_transfer(save_client->adapter, msgs, 2) < 0)
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goto read_err;
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sec1 = sec;
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min1 = min;
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hour1 = hour;
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day1 = day;
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mon1 = mon;
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year1 = year;
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sec = buf[m41t00_chip->sec] & 0x7f;
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min = buf[m41t00_chip->min] & 0x7f;
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hour = buf[m41t00_chip->hour] & 0x3f;
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day = buf[m41t00_chip->day] & 0x3f;
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mon = buf[m41t00_chip->mon] & 0x1f;
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year = buf[m41t00_chip->year];
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} while ((++reads < m41t00_chip->read_limit) && ((sec != sec1)
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|| (min != min1) || (hour != hour1) || (day != day1)
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|| (mon != mon1) || (year != year1)));
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if ((m41t00_chip->read_limit > 1) && ((sec != sec1) || (min != min1)
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|| (hour != hour1) || (day != day1) || (mon != mon1)
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|| (year != year1)))
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goto read_err;
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sec = BCD2BIN(sec);
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min = BCD2BIN(min);
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hour = BCD2BIN(hour);
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day = BCD2BIN(day);
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mon = BCD2BIN(mon);
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year = BCD2BIN(year);
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year += 1900;
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if (year < 1970)
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year += 100;
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return mktime(year, mon, day, hour, min, sec);
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read_err:
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dev_err(&save_client->dev, "m41t00_get_rtc_time: Read error\n");
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return 0;
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}
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EXPORT_SYMBOL_GPL(m41t00_get_rtc_time);
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static void
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m41t00_set(void *arg)
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{
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struct rtc_time tm;
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int nowtime = *(int *)arg;
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s32 sec, min, hour, day, mon, year;
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u8 wbuf[9], *buf = &wbuf[1], msgbuf[1] = { 0 };
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struct i2c_msg msgs[] = {
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{
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.addr = save_client->addr,
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.flags = 0,
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.len = 1,
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.buf = msgbuf,
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},
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{
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.addr = save_client->addr,
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.flags = I2C_M_RD,
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.len = 8,
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.buf = buf,
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},
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};
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to_tm(nowtime, &tm);
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tm.tm_year = (tm.tm_year - 1900) % 100;
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sec = BIN2BCD(tm.tm_sec);
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min = BIN2BCD(tm.tm_min);
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hour = BIN2BCD(tm.tm_hour);
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day = BIN2BCD(tm.tm_mday);
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mon = BIN2BCD(tm.tm_mon);
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year = BIN2BCD(tm.tm_year);
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/* Read reg values into buf[0..7]/wbuf[1..8] */
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if (i2c_transfer(save_client->adapter, msgs, 2) < 0) {
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dev_err(&save_client->dev, "m41t00_set: Read error\n");
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return;
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}
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wbuf[0] = 0; /* offset into rtc's regs */
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buf[m41t00_chip->sec] = (buf[m41t00_chip->sec] & ~0x7f) | (sec & 0x7f);
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buf[m41t00_chip->min] = (buf[m41t00_chip->min] & ~0x7f) | (min & 0x7f);
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buf[m41t00_chip->hour] = (buf[m41t00_chip->hour] & ~0x3f) | (hour& 0x3f);
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buf[m41t00_chip->day] = (buf[m41t00_chip->day] & ~0x3f) | (day & 0x3f);
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buf[m41t00_chip->mon] = (buf[m41t00_chip->mon] & ~0x1f) | (mon & 0x1f);
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if (i2c_master_send(save_client, wbuf, 9) < 0)
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dev_err(&save_client->dev, "m41t00_set: Write error\n");
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}
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static ulong new_time;
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static struct workqueue_struct *m41t00_wq;
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static DECLARE_WORK(m41t00_work, m41t00_set, &new_time);
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int
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m41t00_set_rtc_time(ulong nowtime)
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{
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new_time = nowtime;
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if (in_interrupt())
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queue_work(m41t00_wq, &m41t00_work);
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else
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m41t00_set(&new_time);
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return 0;
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}
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EXPORT_SYMBOL_GPL(m41t00_set_rtc_time);
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/*
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*****************************************************************************
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*
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* platform_data Driver Interface
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*
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*****************************************************************************
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*/
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static int __init
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m41t00_platform_probe(struct platform_device *pdev)
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{
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struct m41t00_platform_data *pdata;
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int i;
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if (pdev && (pdata = pdev->dev.platform_data)) {
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normal_addr[0] = pdata->i2c_addr;
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for (i=0; i<ARRAY_SIZE(m41t00_chip_info_tbl); i++)
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if (m41t00_chip_info_tbl[i].type == pdata->type) {
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m41t00_chip = &m41t00_chip_info_tbl[i];
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m41t00_chip->sqw_freq = pdata->sqw_freq;
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return 0;
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}
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}
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return -ENODEV;
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}
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static int __exit
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m41t00_platform_remove(struct platform_device *pdev)
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{
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return 0;
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}
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static struct platform_driver m41t00_platform_driver = {
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.probe = m41t00_platform_probe,
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.remove = m41t00_platform_remove,
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.driver = {
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.owner = THIS_MODULE,
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.name = M41T00_DRV_NAME,
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},
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};
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/*
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*****************************************************************************
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*
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* Driver Interface
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*
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*****************************************************************************
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*/
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static int
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m41t00_probe(struct i2c_adapter *adap, int addr, int kind)
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{
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struct i2c_client *client;
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int rc;
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if (!i2c_check_functionality(adap, I2C_FUNC_I2C
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| I2C_FUNC_SMBUS_BYTE_DATA))
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return 0;
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client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
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if (!client)
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return -ENOMEM;
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strlcpy(client->name, m41t00_chip->name, I2C_NAME_SIZE);
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client->addr = addr;
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client->adapter = adap;
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client->driver = &m41t00_driver;
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if ((rc = i2c_attach_client(client)))
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goto attach_err;
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if (m41t00_chip->type != M41T00_TYPE_M41T00) {
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/* If asked, disable SQW, set SQW frequency & re-enable */
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if (m41t00_chip->sqw_freq)
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if (((rc = i2c_smbus_read_byte_data(client,
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m41t00_chip->alarm_mon)) < 0)
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|| ((rc = i2c_smbus_write_byte_data(client,
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m41t00_chip->alarm_mon, rc & ~0x40)) <0)
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|| ((rc = i2c_smbus_write_byte_data(client,
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m41t00_chip->sqw,
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m41t00_chip->sqw_freq)) < 0)
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|| ((rc = i2c_smbus_write_byte_data(client,
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m41t00_chip->alarm_mon, rc | 0x40)) <0))
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goto sqw_err;
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/* Make sure HT (Halt Update) bit is cleared */
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if ((rc = i2c_smbus_read_byte_data(client,
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m41t00_chip->alarm_hour)) < 0)
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goto ht_err;
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if (rc & 0x40)
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if ((rc = i2c_smbus_write_byte_data(client,
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m41t00_chip->alarm_hour, rc & ~0x40))<0)
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goto ht_err;
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}
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/* Make sure ST (stop) bit is cleared */
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if ((rc = i2c_smbus_read_byte_data(client, m41t00_chip->sec)) < 0)
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goto st_err;
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if (rc & 0x80)
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if ((rc = i2c_smbus_write_byte_data(client, m41t00_chip->sec,
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rc & ~0x80)) < 0)
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goto st_err;
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m41t00_wq = create_singlethread_workqueue(m41t00_chip->name);
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save_client = client;
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return 0;
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st_err:
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dev_err(&client->dev, "m41t00_probe: Can't clear ST bit\n");
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goto attach_err;
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ht_err:
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dev_err(&client->dev, "m41t00_probe: Can't clear HT bit\n");
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goto attach_err;
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sqw_err:
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dev_err(&client->dev, "m41t00_probe: Can't set SQW Frequency\n");
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attach_err:
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kfree(client);
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return rc;
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}
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static int
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m41t00_attach(struct i2c_adapter *adap)
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{
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return i2c_probe(adap, &addr_data, m41t00_probe);
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}
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static int
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m41t00_detach(struct i2c_client *client)
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{
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int rc;
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if ((rc = i2c_detach_client(client)) == 0) {
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kfree(client);
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destroy_workqueue(m41t00_wq);
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}
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return rc;
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}
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static struct i2c_driver m41t00_driver = {
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.driver = {
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.name = M41T00_DRV_NAME,
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},
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.id = I2C_DRIVERID_STM41T00,
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.attach_adapter = m41t00_attach,
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.detach_client = m41t00_detach,
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};
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static int __init
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m41t00_init(void)
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{
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int rc;
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if (!(rc = platform_driver_register(&m41t00_platform_driver)))
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rc = i2c_add_driver(&m41t00_driver);
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return rc;
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}
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static void __exit
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m41t00_exit(void)
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{
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i2c_del_driver(&m41t00_driver);
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platform_driver_unregister(&m41t00_platform_driver);
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}
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module_init(m41t00_init);
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module_exit(m41t00_exit);
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MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
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MODULE_DESCRIPTION("ST Microelectronics M41T00 RTC I2C Client Driver");
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MODULE_LICENSE("GPL");
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