![David Brownell](/assets/img/avatar_default.png)
Fix bogus #include in rtc-pcf8583, so it compiles on platforms that don't support PC clone RTCs. (Original issue noted by Adrian Bunk.) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Adrian Bunk <bunk@kernel.org> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
389 lines
7.8 KiB
C
389 lines
7.8 KiB
C
/*
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* drivers/rtc/rtc-pcf8583.c
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*
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* Copyright (C) 2000 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Driver for PCF8583 RTC & RAM chip
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*
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* Converted to the generic RTC susbsystem by G. Liakhovetski (2006)
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*/
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/rtc.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/bcd.h>
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struct rtc_mem {
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unsigned int loc;
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unsigned int nr;
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unsigned char *data;
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};
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struct pcf8583 {
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struct i2c_client client;
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struct rtc_device *rtc;
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unsigned char ctrl;
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};
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#define CTRL_STOP 0x80
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#define CTRL_HOLD 0x40
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#define CTRL_32KHZ 0x00
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#define CTRL_MASK 0x08
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#define CTRL_ALARMEN 0x04
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#define CTRL_ALARM 0x02
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#define CTRL_TIMER 0x01
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static const unsigned short normal_i2c[] = { 0x50, I2C_CLIENT_END };
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/* Module parameters */
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I2C_CLIENT_INSMOD;
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static struct i2c_driver pcf8583_driver;
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#define get_ctrl(x) ((struct pcf8583 *)i2c_get_clientdata(x))->ctrl
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#define set_ctrl(x, v) get_ctrl(x) = v
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#define CMOS_YEAR (64 + 128)
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#define CMOS_CHECKSUM (63)
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static int pcf8583_get_datetime(struct i2c_client *client, struct rtc_time *dt)
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{
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unsigned char buf[8], addr[1] = { 1 };
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struct i2c_msg msgs[2] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1,
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.buf = addr,
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}, {
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.addr = client->addr,
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.flags = I2C_M_RD,
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.len = 6,
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.buf = buf,
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}
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};
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int ret;
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memset(buf, 0, sizeof(buf));
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ret = i2c_transfer(client->adapter, msgs, 2);
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if (ret == 2) {
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dt->tm_year = buf[4] >> 6;
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dt->tm_wday = buf[5] >> 5;
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buf[4] &= 0x3f;
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buf[5] &= 0x1f;
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dt->tm_sec = BCD2BIN(buf[1]);
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dt->tm_min = BCD2BIN(buf[2]);
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dt->tm_hour = BCD2BIN(buf[3]);
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dt->tm_mday = BCD2BIN(buf[4]);
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dt->tm_mon = BCD2BIN(buf[5]) - 1;
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}
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return ret == 2 ? 0 : -EIO;
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}
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static int pcf8583_set_datetime(struct i2c_client *client, struct rtc_time *dt, int datetoo)
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{
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unsigned char buf[8];
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int ret, len = 6;
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buf[0] = 0;
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buf[1] = get_ctrl(client) | 0x80;
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buf[2] = 0;
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buf[3] = BIN2BCD(dt->tm_sec);
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buf[4] = BIN2BCD(dt->tm_min);
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buf[5] = BIN2BCD(dt->tm_hour);
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if (datetoo) {
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len = 8;
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buf[6] = BIN2BCD(dt->tm_mday) | (dt->tm_year << 6);
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buf[7] = BIN2BCD(dt->tm_mon + 1) | (dt->tm_wday << 5);
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}
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ret = i2c_master_send(client, (char *)buf, len);
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if (ret != len)
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return -EIO;
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buf[1] = get_ctrl(client);
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ret = i2c_master_send(client, (char *)buf, 2);
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return ret == 2 ? 0 : -EIO;
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}
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static int pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl)
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{
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*ctrl = get_ctrl(client);
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return 0;
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}
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static int pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl)
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{
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unsigned char buf[2];
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buf[0] = 0;
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buf[1] = *ctrl;
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set_ctrl(client, *ctrl);
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return i2c_master_send(client, (char *)buf, 2);
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}
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static int pcf8583_read_mem(struct i2c_client *client, struct rtc_mem *mem)
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{
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unsigned char addr[1];
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struct i2c_msg msgs[2] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1,
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.buf = addr,
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}, {
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.addr = client->addr,
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.flags = I2C_M_RD,
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.len = mem->nr,
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.buf = mem->data,
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}
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};
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if (mem->loc < 8)
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return -EINVAL;
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addr[0] = mem->loc;
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return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
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}
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static int pcf8583_write_mem(struct i2c_client *client, struct rtc_mem *mem)
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{
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unsigned char buf[9];
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int ret;
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if (mem->loc < 8 || mem->nr > 8)
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return -EINVAL;
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buf[0] = mem->loc;
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memcpy(buf + 1, mem->data, mem->nr);
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ret = i2c_master_send(client, buf, mem->nr + 1);
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return ret == mem->nr + 1 ? 0 : -EIO;
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}
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static int pcf8583_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct i2c_client *client = to_i2c_client(dev);
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unsigned char ctrl, year[2];
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struct rtc_mem mem = { CMOS_YEAR, sizeof(year), year };
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int real_year, year_offset, err;
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/*
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* Ensure that the RTC is running.
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*/
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pcf8583_get_ctrl(client, &ctrl);
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if (ctrl & (CTRL_STOP | CTRL_HOLD)) {
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unsigned char new_ctrl = ctrl & ~(CTRL_STOP | CTRL_HOLD);
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printk(KERN_WARNING "RTC: resetting control %02x -> %02x\n",
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ctrl, new_ctrl);
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if ((err = pcf8583_set_ctrl(client, &new_ctrl)) < 0)
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return err;
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}
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if (pcf8583_get_datetime(client, tm) ||
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pcf8583_read_mem(client, &mem))
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return -EIO;
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real_year = year[0];
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/*
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* The RTC year holds the LSB two bits of the current
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* year, which should reflect the LSB two bits of the
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* CMOS copy of the year. Any difference indicates
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* that we have to correct the CMOS version.
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*/
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year_offset = tm->tm_year - (real_year & 3);
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if (year_offset < 0)
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/*
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* RTC year wrapped. Adjust it appropriately.
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*/
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year_offset += 4;
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tm->tm_year = (real_year + year_offset + year[1] * 100) - 1900;
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return 0;
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}
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static int pcf8583_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct i2c_client *client = to_i2c_client(dev);
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unsigned char year[2], chk;
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struct rtc_mem cmos_year = { CMOS_YEAR, sizeof(year), year };
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struct rtc_mem cmos_check = { CMOS_CHECKSUM, 1, &chk };
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unsigned int proper_year = tm->tm_year + 1900;
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int ret;
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/*
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* The RTC's own 2-bit year must reflect the least
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* significant two bits of the CMOS year.
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*/
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ret = pcf8583_set_datetime(client, tm, 1);
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if (ret)
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return ret;
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ret = pcf8583_read_mem(client, &cmos_check);
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if (ret)
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return ret;
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ret = pcf8583_read_mem(client, &cmos_year);
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if (ret)
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return ret;
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chk -= year[1] + year[0];
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year[1] = proper_year / 100;
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year[0] = proper_year % 100;
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chk += year[1] + year[0];
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ret = pcf8583_write_mem(client, &cmos_year);
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if (ret)
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return ret;
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ret = pcf8583_write_mem(client, &cmos_check);
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return ret;
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}
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static const struct rtc_class_ops pcf8583_rtc_ops = {
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.read_time = pcf8583_rtc_read_time,
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.set_time = pcf8583_rtc_set_time,
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};
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static int pcf8583_probe(struct i2c_adapter *adap, int addr, int kind);
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static int pcf8583_attach(struct i2c_adapter *adap)
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{
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return i2c_probe(adap, &addr_data, pcf8583_probe);
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}
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static int pcf8583_detach(struct i2c_client *client)
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{
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int err;
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struct pcf8583 *pcf = i2c_get_clientdata(client);
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struct rtc_device *rtc = pcf->rtc;
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if (rtc)
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rtc_device_unregister(rtc);
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if ((err = i2c_detach_client(client)))
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return err;
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kfree(pcf);
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return 0;
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}
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static struct i2c_driver pcf8583_driver = {
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.driver = {
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.name = "pcf8583",
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},
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.id = I2C_DRIVERID_PCF8583,
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.attach_adapter = pcf8583_attach,
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.detach_client = pcf8583_detach,
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};
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static int pcf8583_probe(struct i2c_adapter *adap, int addr, int kind)
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{
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struct pcf8583 *pcf;
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struct i2c_client *client;
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struct rtc_device *rtc;
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unsigned char buf[1], ad[1] = { 0 };
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int err;
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struct i2c_msg msgs[2] = {
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{
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.addr = addr,
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.flags = 0,
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.len = 1,
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.buf = ad,
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}, {
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.addr = addr,
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.flags = I2C_M_RD,
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.len = 1,
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.buf = buf,
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}
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};
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if (!i2c_check_functionality(adap, I2C_FUNC_I2C))
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return 0;
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pcf = kzalloc(sizeof(*pcf), GFP_KERNEL);
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if (!pcf)
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return -ENOMEM;
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client = &pcf->client;
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client->addr = addr;
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client->adapter = adap;
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client->driver = &pcf8583_driver;
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strlcpy(client->name, pcf8583_driver.driver.name, I2C_NAME_SIZE);
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if (i2c_transfer(client->adapter, msgs, 2) != 2) {
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err = -EIO;
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goto exit_kfree;
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}
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err = i2c_attach_client(client);
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if (err)
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goto exit_kfree;
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rtc = rtc_device_register(pcf8583_driver.driver.name, &client->dev,
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&pcf8583_rtc_ops, THIS_MODULE);
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if (IS_ERR(rtc)) {
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err = PTR_ERR(rtc);
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goto exit_detach;
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}
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pcf->rtc = rtc;
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i2c_set_clientdata(client, pcf);
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set_ctrl(client, buf[0]);
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return 0;
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exit_detach:
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i2c_detach_client(client);
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exit_kfree:
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kfree(pcf);
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return err;
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}
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static __init int pcf8583_init(void)
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{
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return i2c_add_driver(&pcf8583_driver);
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}
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static __exit void pcf8583_exit(void)
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{
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i2c_del_driver(&pcf8583_driver);
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}
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module_init(pcf8583_init);
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module_exit(pcf8583_exit);
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MODULE_AUTHOR("Russell King");
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MODULE_DESCRIPTION("PCF8583 I2C RTC driver");
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MODULE_LICENSE("GPL");
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