diff options
Diffstat (limited to 'drivers/acorn/char/i2c.c')
| -rw-r--r-- | drivers/acorn/char/i2c.c | 368 |
1 files changed, 0 insertions, 368 deletions
diff --git a/drivers/acorn/char/i2c.c b/drivers/acorn/char/i2c.c deleted file mode 100644 index d276fd1..0000000 --- a/drivers/acorn/char/i2c.c +++ /dev/null @@ -1,368 +0,0 @@ -/* - * linux/drivers/acorn/char/i2c.c - * - * Copyright (C) 2000 Russell King - * - * 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. - * - * ARM IOC/IOMD i2c driver. - * - * On Acorn machines, the following i2c devices are on the bus: - * - PCF8583 real time clock & static RAM - */ -#include <linux/capability.h> -#include <linux/init.h> -#include <linux/time.h> -#include <linux/miscdevice.h> -#include <linux/rtc.h> -#include <linux/i2c.h> -#include <linux/i2c-algo-bit.h> -#include <linux/fs.h> - -#include <asm/hardware.h> -#include <asm/io.h> -#include <asm/hardware/ioc.h> -#include <asm/system.h> -#include <asm/uaccess.h> - -#include "pcf8583.h" - -extern int (*set_rtc)(void); - -static struct i2c_client *rtc_client; -static const unsigned char days_in_mon[] = - { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; - -#define CMOS_CHECKSUM (63) - -/* - * Acorn machines store the year in the static RAM at - * location 128. - */ -#define CMOS_YEAR (64 + 128) - -static inline int rtc_command(int cmd, void *data) -{ - int ret = -EIO; - - if (rtc_client) - ret = rtc_client->driver->command(rtc_client, cmd, data); - - return ret; -} - -/* - * Update the century + year bytes in the CMOS RAM, ensuring - * that the check byte is correctly adjusted for the change. - */ -static int rtc_update_year(unsigned int new_year) -{ - unsigned char yr[2], chk; - struct mem cmos_year = { CMOS_YEAR, sizeof(yr), yr }; - struct mem cmos_check = { CMOS_CHECKSUM, 1, &chk }; - int ret; - - ret = rtc_command(MEM_READ, &cmos_check); - if (ret) - goto out; - ret = rtc_command(MEM_READ, &cmos_year); - if (ret) - goto out; - - chk -= yr[1] + yr[0]; - - yr[1] = new_year / 100; - yr[0] = new_year % 100; - - chk += yr[1] + yr[0]; - - ret = rtc_command(MEM_WRITE, &cmos_year); - if (ret == 0) - ret = rtc_command(MEM_WRITE, &cmos_check); - out: - return ret; -} - -/* - * Read the current RTC time and date, and update xtime. - */ -static void get_rtc_time(struct rtc_tm *rtctm, unsigned int *year) -{ - unsigned char ctrl, yr[2]; - struct mem rtcmem = { CMOS_YEAR, sizeof(yr), yr }; - int real_year, year_offset; - - /* - * Ensure that the RTC is running. - */ - rtc_command(RTC_GETCTRL, &ctrl); - if (ctrl & 0xc0) { - unsigned char new_ctrl = ctrl & ~0xc0; - - printk(KERN_WARNING "RTC: resetting control %02x -> %02x\n", - ctrl, new_ctrl); - - rtc_command(RTC_SETCTRL, &new_ctrl); - } - - if (rtc_command(RTC_GETDATETIME, rtctm) || - rtc_command(MEM_READ, &rtcmem)) - return; - - real_year = yr[0]; - - /* - * The RTC year holds the LSB two bits of the current - * year, which should reflect the LSB two bits of the - * CMOS copy of the year. Any difference indicates - * that we have to correct the CMOS version. - */ - year_offset = rtctm->year_off - (real_year & 3); - if (year_offset < 0) - /* - * RTC year wrapped. Adjust it appropriately. - */ - year_offset += 4; - - *year = real_year + year_offset + yr[1] * 100; -} - -static int set_rtc_time(struct rtc_tm *rtctm, unsigned int year) -{ - unsigned char leap; - int ret; - - leap = (!(year % 4) && (year % 100)) || !(year % 400); - - if (rtctm->mon > 12 || rtctm->mon == 0 || rtctm->mday == 0) - return -EINVAL; - - if (rtctm->mday > (days_in_mon[rtctm->mon] + (rtctm->mon == 2 && leap))) - return -EINVAL; - - if (rtctm->hours >= 24 || rtctm->mins >= 60 || rtctm->secs >= 60) - return -EINVAL; - - /* - * The RTC's own 2-bit year must reflect the least - * significant two bits of the CMOS year. - */ - rtctm->year_off = (year % 100) & 3; - - ret = rtc_command(RTC_SETDATETIME, rtctm); - if (ret == 0) - ret = rtc_update_year(year); - - return ret; -} - -/* - * Set the RTC time only. Note that - * we do not touch the date. - */ -static int k_set_rtc_time(void) -{ - struct rtc_tm new_rtctm, old_rtctm; - unsigned long nowtime = xtime.tv_sec; - - if (rtc_command(RTC_GETDATETIME, &old_rtctm)) - return 0; - - new_rtctm.cs = xtime.tv_nsec / 10000000; - new_rtctm.secs = nowtime % 60; nowtime /= 60; - new_rtctm.mins = nowtime % 60; nowtime /= 60; - new_rtctm.hours = nowtime % 24; - - /* - * avoid writing when we're going to change the day - * of the month. We will retry in the next minute. - * This basically means that if the RTC must not drift - * by more than 1 minute in 11 minutes. - * - * [ rtc: 1/1/2000 23:58:00, real 2/1/2000 00:01:00, - * rtc gets set to 1/1/2000 00:01:00 ] - */ - if ((old_rtctm.hours == 23 && old_rtctm.mins == 59) || - (new_rtctm.hours == 23 && new_rtctm.mins == 59)) - return 1; - - return rtc_command(RTC_SETTIME, &new_rtctm); -} - -static int rtc_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) -{ - unsigned int year; - struct rtc_time rtctm; - struct rtc_tm rtc_raw; - - switch (cmd) { - case RTC_ALM_READ: - case RTC_ALM_SET: - break; - - case RTC_RD_TIME: - memset(&rtctm, 0, sizeof(struct rtc_time)); - get_rtc_time(&rtc_raw, &year); - rtctm.tm_sec = rtc_raw.secs; - rtctm.tm_min = rtc_raw.mins; - rtctm.tm_hour = rtc_raw.hours; - rtctm.tm_mday = rtc_raw.mday; - rtctm.tm_mon = rtc_raw.mon - 1; /* month starts at 0 */ - rtctm.tm_year = year - 1900; /* starts at 1900 */ - return copy_to_user((void *)arg, &rtctm, sizeof(rtctm)) - ? -EFAULT : 0; - - case RTC_SET_TIME: - if (!capable(CAP_SYS_TIME)) - return -EACCES; - - if (copy_from_user(&rtctm, (void *)arg, sizeof(rtctm))) - return -EFAULT; - rtc_raw.secs = rtctm.tm_sec; - rtc_raw.mins = rtctm.tm_min; - rtc_raw.hours = rtctm.tm_hour; - rtc_raw.mday = rtctm.tm_mday; - rtc_raw.mon = rtctm.tm_mon + 1; - year = rtctm.tm_year + 1900; - return set_rtc_time(&rtc_raw, year); - break; - - case RTC_EPOCH_READ: - return put_user(1900, (unsigned long *)arg); - - } - return -EINVAL; -} - -static const struct file_operations rtc_fops = { - .ioctl = rtc_ioctl, -}; - -static struct miscdevice rtc_dev = { - .minor = RTC_MINOR, - .name = "rtc", - .fops = &rtc_fops, -}; - -/* IOC / IOMD i2c driver */ - -#define FORCE_ONES 0xdc -#define SCL 0x02 -#define SDA 0x01 - -/* - * We must preserve all non-i2c output bits in IOC_CONTROL. - * Note also that we need to preserve the value of SCL and - * SDA outputs as well (which may be different from the - * values read back from IOC_CONTROL). - */ -static u_int force_ones; - -static void ioc_setscl(void *data, int state) -{ - u_int ioc_control = ioc_readb(IOC_CONTROL) & ~(SCL | SDA); - u_int ones = force_ones; - - if (state) - ones |= SCL; - else - ones &= ~SCL; - - force_ones = ones; - - ioc_writeb(ioc_control | ones, IOC_CONTROL); -} - -static void ioc_setsda(void *data, int state) -{ - u_int ioc_control = ioc_readb(IOC_CONTROL) & ~(SCL | SDA); - u_int ones = force_ones; - - if (state) - ones |= SDA; - else - ones &= ~SDA; - - force_ones = ones; - - ioc_writeb(ioc_control | ones, IOC_CONTROL); -} - -static int ioc_getscl(void *data) -{ - return (ioc_readb(IOC_CONTROL) & SCL) != 0; -} - -static int ioc_getsda(void *data) -{ - return (ioc_readb(IOC_CONTROL) & SDA) != 0; -} - -static struct i2c_algo_bit_data ioc_data = { - .setsda = ioc_setsda, - .setscl = ioc_setscl, - .getsda = ioc_getsda, - .getscl = ioc_getscl, - .udelay = 80, - .timeout = 100 -}; - -static int ioc_client_reg(struct i2c_client *client) -{ - if (client->driver->id == I2C_DRIVERID_PCF8583 && - client->addr == 0x50) { - struct rtc_tm rtctm; - unsigned int year; - struct timespec tv; - - rtc_client = client; - get_rtc_time(&rtctm, &year); - - tv.tv_nsec = rtctm.cs * 10000000; - tv.tv_sec = mktime(year, rtctm.mon, rtctm.mday, - rtctm.hours, rtctm.mins, rtctm.secs); - do_settimeofday(&tv); - set_rtc = k_set_rtc_time; - } - - return 0; -} - -static int ioc_client_unreg(struct i2c_client *client) -{ - if (client == rtc_client) { - set_rtc = NULL; - rtc_client = NULL; - } - - return 0; -} - -static struct i2c_adapter ioc_ops = { - .id = I2C_HW_B_IOC, - .algo_data = &ioc_data, - .client_register = ioc_client_reg, - .client_unregister = ioc_client_unreg, -}; - -static int __init i2c_ioc_init(void) -{ - int ret; - - force_ones = FORCE_ONES | SCL | SDA; - - ret = i2c_bit_add_bus(&ioc_ops); - - if (ret >= 0){ - ret = misc_register(&rtc_dev); - if(ret < 0) - i2c_del_adapter(&ioc_ops); - } - - return ret; -} - -__initcall(i2c_ioc_init); |