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- /*
- * Real Time Clock driver for WL-HDD
- *
- * Copyright (C) 2007 Andreas Engel
- *
- * Hacked together mostly by copying the relevant code parts from:
- * drivers/i2c/i2c-bcm5365.c
- * drivers/i2c/i2c-algo-bit.c
- * drivers/char/rtc.c
- *
- * Note 1:
- * This module uses the standard char device (10,135), while the Asus module
- * rtcdrv.o uses (12,0). So, both can coexist which might be handy during
- * development (but see the comment in rtc_open()).
- *
- * Note 2:
- * You might need to set the clock once after loading the driver the first
- * time because the driver switches the chip into 24h mode if it is running
- * in 12h mode.
- *
- * Usage:
- * For compatibility reasons with the original asus driver, the time can be
- * read and set via the /dev/rtc device entry. The only accepted data format
- * is "YYYY:MM:DD:W:HH:MM:SS\n". See OpenWrt wiki for a script which handles
- * this format.
- *
- * In addition, this driver supports the standard ioctl() calls for setting
- * and reading the hardware clock, so the ordinary hwclock utility can also
- * be used.
- *
- * 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.
- *
- * TODO:
- * - add a /proc/driver/rtc interface?
- * - make the battery failure bit available through the /proc interface?
- *
- * $Id: rtc.c 7 2007-05-25 19:37:01Z ae $
- */
- #include <linux/module.h>
- #include <linux/kmod.h>
- #include <linux/kernel.h>
- #include <linux/types.h>
- #include <linux/miscdevice.h>
- #include <linux/ioport.h>
- #include <linux/fcntl.h>
- #include <linux/mc146818rtc.h>
- #include <linux/init.h>
- #include <linux/spinlock.h>
- #include <linux/rtc.h>
- #include <linux/delay.h>
- #include <linux/version.h>
- #include <linux/gpio.h>
- #include <linux/uaccess.h>
- #include <asm/current.h>
- #if LINUX_VERSION_CODE < KERNEL_VERSION(3,4,0)
- #include <asm/system.h>
- #endif
- #include <bcm47xx.h>
- #include <linux/bcm47xx_nvram.h>
- #define RTC_IS_OPEN 0x01 /* Means /dev/rtc is in use. */
- /* Can be changed via a module parameter. */
- static int rtc_debug = 0;
- static unsigned long rtc_status = 0; /* Bitmapped status byte. */
- /* These settings are platform dependents. */
- unsigned int sda_index = 0;
- unsigned int scl_index = 0;
- #define I2C_READ_MASK 1
- #define I2C_WRITE_MASK 0
- #define I2C_ACK 1
- #define I2C_NAK 0
- #define RTC_EPOCH 1900
- #define RTC_I2C_ADDRESS (0x32 << 1)
- #define RTC_24HOUR_MODE_MASK 0x20
- #define RTC_PM_MASK 0x20
- #define RTC_VDET_MASK 0x40
- #define RTC_Y2K_MASK 0x80
- /*
- * Delay in microseconds for generating the pulses on the I2C bus. We use
- * a rather conservative setting here. See datasheet of the RTC chip.
- */
- #define ADAP_DELAY 50
- /* Avoid spurious compiler warnings. */
- #define UNUSED __attribute__((unused))
- MODULE_AUTHOR("Andreas Engel");
- MODULE_LICENSE("GPL");
- /* Test stolen from switch-adm.c. */
- module_param(rtc_debug, int, 0);
- static inline void sdalo(void)
- {
- gpio_direction_output(sda_index, 1);
- udelay(ADAP_DELAY);
- }
- static inline void sdahi(void)
- {
- gpio_direction_input(sda_index);
- udelay(ADAP_DELAY);
- }
- static inline void scllo(void)
- {
- gpio_direction_output(scl_index, 1);
- udelay(ADAP_DELAY);
- }
- static inline int getscl(void)
- {
- return (gpio_get_value(scl_index));
- }
- static inline int getsda(void)
- {
- return (gpio_get_value(sda_index));
- }
- /*
- * We shouldn't simply set the SCL pin to high. Like SDA, the SCL line is
- * bidirectional too. According to the I2C spec, the slave is allowed to
- * pull down the SCL line to slow down the clock, so we need to check this.
- * Generally, we'd need a timeout here, but in our case, we just check the
- * line, assuming the RTC chip behaves well.
- */
- static int sclhi(void)
- {
- gpio_direction_input(scl_index);
- udelay(ADAP_DELAY);
- if (!getscl()) {
- printk(KERN_ERR "SCL pin should be low\n");
- return -ETIMEDOUT;
- }
- return 0;
- }
- static void i2c_start(void)
- {
- sdalo();
- scllo();
- }
- static void i2c_stop(void)
- {
- sdalo();
- sclhi();
- sdahi();
- }
- static int i2c_outb(int c)
- {
- int i;
- int ack;
- /* assert: scl is low */
- for (i = 7; i >= 0; i--) {
- if (c & ( 1 << i )) {
- sdahi();
- } else {
- sdalo();
- }
- if (sclhi() < 0) { /* timed out */
- sdahi(); /* we don't want to block the net */
- return -ETIMEDOUT;
- };
- scllo();
- }
- sdahi();
- if (sclhi() < 0) {
- return -ETIMEDOUT;
- };
- /* read ack: SDA should be pulled down by slave */
- ack = getsda() == 0; /* ack: sda is pulled low ->success. */
- scllo();
- if (rtc_debug)
- printk(KERN_DEBUG "i2c_outb(0x%02x) -> %s\n",
- c, ack ? "ACK": "NAK");
- return ack; /* return 1 if device acked */
- /* assert: scl is low (sda undef) */
- }
- static int i2c_inb(int ack)
- {
- int i;
- unsigned int indata = 0;
- /* assert: scl is low */
- sdahi();
- for (i = 0; i < 8; i++) {
- if (sclhi() < 0) {
- return -ETIMEDOUT;
- };
- indata *= 2;
- if (getsda())
- indata |= 0x01;
- scllo();
- }
- if (ack) {
- sdalo();
- } else {
- sdahi();
- }
- if (sclhi() < 0) {
- sdahi();
- return -ETIMEDOUT;
- }
- scllo();
- sdahi();
- if (rtc_debug)
- printk(KERN_DEBUG "i2c_inb() -> 0x%02x\n", indata);
- /* assert: scl is low */
- return indata & 0xff;
- }
- static void i2c_init(void)
- {
- /* no gpio_control for EXTIF */
- // ssb_gpio_control(&ssb, sda_mask | scl_mask, 0);
- gpio_set_value(sda_index, 0);
- gpio_set_value(scl_index, 0);
- sdahi();
- sclhi();
- }
- static int rtc_open(UNUSED struct inode *inode, UNUSED struct file *filp)
- {
- spin_lock_irq(&rtc_lock);
- if (rtc_status & RTC_IS_OPEN) {
- spin_unlock_irq(&rtc_lock);
- return -EBUSY;
- }
- rtc_status |= RTC_IS_OPEN;
- /*
- * The following call is only necessary if we use both this driver and
- * the proprietary one from asus at the same time (which, b.t.w. only
- * makes sense during development). Otherwise, each access via the asus
- * driver will make access via this driver impossible.
- */
- i2c_init();
- spin_unlock_irq(&rtc_lock);
- return 0;
- }
- static int rtc_release(UNUSED struct inode *inode, UNUSED struct file *filp)
- {
- /* No need for locking here. */
- rtc_status &= ~RTC_IS_OPEN;
- return 0;
- }
- static int from_bcd(int bcdnum)
- {
- int fac, num = 0;
- for (fac = 1; bcdnum; fac *= 10) {
- num += (bcdnum % 16) * fac;
- bcdnum /= 16;
- }
- return num;
- }
- static int to_bcd(int decnum)
- {
- int fac, num = 0;
- for (fac = 1; decnum; fac *= 16) {
- num += (decnum % 10) * fac;
- decnum /= 10;
- }
- return num;
- }
- static void get_rtc_time(struct rtc_time *rtc_tm)
- {
- int cr2;
- /*
- * Read date and time from the RTC. We use read method (3).
- */
- spin_lock_irq(&rtc_lock);
- i2c_start();
- i2c_outb(RTC_I2C_ADDRESS | I2C_READ_MASK);
- cr2 = i2c_inb(I2C_ACK);
- rtc_tm->tm_sec = i2c_inb(I2C_ACK);
- rtc_tm->tm_min = i2c_inb(I2C_ACK);
- rtc_tm->tm_hour = i2c_inb(I2C_ACK);
- rtc_tm->tm_wday = i2c_inb(I2C_ACK);
- rtc_tm->tm_mday = i2c_inb(I2C_ACK);
- rtc_tm->tm_mon = i2c_inb(I2C_ACK);
- rtc_tm->tm_year = i2c_inb(I2C_NAK);
- i2c_stop();
- spin_unlock_irq(&rtc_lock);
- if (cr2 & RTC_VDET_MASK) {
- printk(KERN_WARNING "***RTC BATTERY FAILURE***\n");
- }
- /* Handle century bit */
- if (rtc_tm->tm_mon & RTC_Y2K_MASK) {
- rtc_tm->tm_mon &= ~RTC_Y2K_MASK;
- rtc_tm->tm_year += 0x100;
- }
- rtc_tm->tm_sec = from_bcd(rtc_tm->tm_sec);
- rtc_tm->tm_min = from_bcd(rtc_tm->tm_min);
- rtc_tm->tm_hour = from_bcd(rtc_tm->tm_hour);
- rtc_tm->tm_mday = from_bcd(rtc_tm->tm_mday);
- rtc_tm->tm_mon = from_bcd(rtc_tm->tm_mon) - 1;
- rtc_tm->tm_year = from_bcd(rtc_tm->tm_year);
- rtc_tm->tm_isdst = -1; /* DST not known */
- }
- static void set_rtc_time(struct rtc_time *rtc_tm)
- {
- rtc_tm->tm_sec = to_bcd(rtc_tm->tm_sec);
- rtc_tm->tm_min = to_bcd(rtc_tm->tm_min);
- rtc_tm->tm_hour = to_bcd(rtc_tm->tm_hour);
- rtc_tm->tm_mday = to_bcd(rtc_tm->tm_mday);
- rtc_tm->tm_mon = to_bcd(rtc_tm->tm_mon + 1);
- rtc_tm->tm_year = to_bcd(rtc_tm->tm_year);
- if (rtc_tm->tm_year >= 0x100) {
- rtc_tm->tm_year -= 0x100;
- rtc_tm->tm_mon |= RTC_Y2K_MASK;
- }
- spin_lock_irq(&rtc_lock);
- i2c_start();
- i2c_outb(RTC_I2C_ADDRESS | I2C_WRITE_MASK);
- i2c_outb(0x00); /* set starting register to 0 (=seconds) */
- i2c_outb(rtc_tm->tm_sec);
- i2c_outb(rtc_tm->tm_min);
- i2c_outb(rtc_tm->tm_hour);
- i2c_outb(rtc_tm->tm_wday);
- i2c_outb(rtc_tm->tm_mday);
- i2c_outb(rtc_tm->tm_mon);
- i2c_outb(rtc_tm->tm_year);
- i2c_stop();
- spin_unlock_irq(&rtc_lock);
- }
- static ssize_t rtc_write(UNUSED struct file *filp, const char *buf,
- size_t count, loff_t *ppos)
- {
- struct rtc_time rtc_tm;
- char buffer[23];
- char *p;
- if (!capable(CAP_SYS_TIME))
- return -EACCES;
- if (ppos != &filp->f_pos)
- return -ESPIPE;
- /*
- * For simplicity, the only acceptable format is:
- * YYYY:MM:DD:W:HH:MM:SS\n
- */
- if (count != 22)
- goto err_out;
- if (copy_from_user(buffer, buf, count))
- return -EFAULT;
- buffer[sizeof(buffer)-1] = '\0';
- p = &buffer[0];
- rtc_tm.tm_year = simple_strtoul(p, &p, 10);
- if (*p++ != ':') goto err_out;
- rtc_tm.tm_mon = simple_strtoul(p, &p, 10) - 1;
- if (*p++ != ':') goto err_out;
- rtc_tm.tm_mday = simple_strtoul(p, &p, 10);
- if (*p++ != ':') goto err_out;
- rtc_tm.tm_wday = simple_strtoul(p, &p, 10);
- if (*p++ != ':') goto err_out;
- rtc_tm.tm_hour = simple_strtoul(p, &p, 10);
- if (*p++ != ':') goto err_out;
- rtc_tm.tm_min = simple_strtoul(p, &p, 10);
- if (*p++ != ':') goto err_out;
- rtc_tm.tm_sec = simple_strtoul(p, &p, 10);
- if (*p != '\n') goto err_out;
- rtc_tm.tm_year -= RTC_EPOCH;
- set_rtc_time(&rtc_tm);
- *ppos += count;
- return count;
- err_out:
- printk(KERN_ERR "invalid format: use YYYY:MM:DD:W:HH:MM:SS\\n\n");
- return -EINVAL;
- }
- static ssize_t rtc_read(UNUSED struct file *filp, char *buf, size_t count,
- loff_t *ppos)
- {
- char wbuf[23];
- struct rtc_time tm;
- ssize_t len;
- if (count == 0 || *ppos != 0)
- return 0;
- get_rtc_time(&tm);
- len = sprintf(wbuf, "%04d:%02d:%02d:%d:%02d:%02d:%02d\n",
- tm.tm_year + RTC_EPOCH,
- tm.tm_mon + 1,
- tm.tm_mday,
- tm.tm_wday,
- tm.tm_hour,
- tm.tm_min,
- tm.tm_sec);
- if (len > (ssize_t)count)
- len = count;
- if (copy_to_user(buf, wbuf, len))
- return -EFAULT;
- *ppos += len;
- return len;
- }
- static int rtc_do_ioctl(unsigned int cmd, unsigned long arg)
- {
- struct rtc_time rtc_tm;
- switch (cmd) {
- case RTC_RD_TIME:
- memset(&rtc_tm, 0, sizeof(struct rtc_time));
- get_rtc_time(&rtc_tm);
- if (copy_to_user((void *)arg, &rtc_tm, sizeof(rtc_tm)))
- return -EFAULT;
- break;
- case RTC_SET_TIME:
- if (!capable(CAP_SYS_TIME))
- return -EACCES;
- if (copy_from_user(&rtc_tm, (struct rtc_time *)arg,
- sizeof(struct rtc_time)))
- return -EFAULT;
- set_rtc_time(&rtc_tm);
- break;
- default:
- return -ENOTTY;
- }
- return 0;
- }
- static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
- {
- long ret;
- ret = rtc_do_ioctl(cmd, arg);
- return ret;
- }
- static const struct file_operations rtc_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .read = rtc_read,
- .write = rtc_write,
- .unlocked_ioctl = rtc_ioctl,
- .open = rtc_open,
- .release = rtc_release,
- };
- static struct miscdevice rtc_dev = {
- .minor = RTC_MINOR,
- .name = "rtc",
- .fops = &rtc_fops,
- };
- /* Savagely ripped from diag.c. */
- static inline int startswith (char *source, char *cmp)
- {
- return !strncmp(source, cmp, strlen(cmp));
- }
- static void platform_detect(void)
- {
- char buf[20];
- int et0phyaddr, et1phyaddr;
- /* Based on "model_no". */
- if (bcm47xx_nvram_getenv("model_no", buf, sizeof(buf)) >= 0) {
- if (startswith(buf, "WL700")) { /* WL700* */
- sda_index = 2;
- scl_index = 5;
- return;
- }
- }
- if (bcm47xx_nvram_getenv("et0phyaddr", buf, sizeof(buf)) >= 0 )
- et0phyaddr = simple_strtoul(buf, NULL, 0);
- if (bcm47xx_nvram_getenv("et1phyaddr", buf, sizeof(buf)) >= 0 )
- et1phyaddr = simple_strtoul(buf, NULL, 0);
- if (bcm47xx_nvram_getenv("hardware_version", buf, sizeof(buf)) >= 0) {
- /* Either WL-300g or WL-HDD, do more extensive checks */
- if (startswith(buf, "WL300-") && et0phyaddr == 0 && et1phyaddr == 1) {
- sda_index = 4;
- scl_index = 5;
- return;
- }
- }
- /* not found */
- }
- static int __init rtc_init(void)
- {
- int cr1;
- platform_detect();
- if (sda_index == scl_index) {
- printk(KERN_ERR "RTC-RV5C386A: unrecognized platform!\n");
- return -ENODEV;
- }
- i2c_init();
- /*
- * Switch RTC to 24h mode
- */
- spin_lock_irq(&rtc_lock);
- i2c_start();
- i2c_outb(RTC_I2C_ADDRESS | I2C_WRITE_MASK);
- i2c_outb(0xE4); /* start at address 0xE, transmission mode 4 */
- cr1 = i2c_inb(I2C_NAK);
- i2c_stop();
- spin_unlock_irq(&rtc_lock);
- if ((cr1 & RTC_24HOUR_MODE_MASK) == 0) {
- /* RTC is running in 12h mode */
- printk(KERN_INFO "rtc.o: switching to 24h mode\n");
- spin_lock_irq(&rtc_lock);
- i2c_start();
- i2c_outb(RTC_I2C_ADDRESS | I2C_WRITE_MASK);
- i2c_outb(0xE0);
- i2c_outb(cr1 | RTC_24HOUR_MODE_MASK);
- i2c_stop();
- spin_unlock_irq(&rtc_lock);
- }
- misc_register(&rtc_dev);
- printk(KERN_INFO "RV5C386A Real Time Clock Driver loaded\n");
- return 0;
- }
- static void __exit rtc_exit (void)
- {
- misc_deregister(&rtc_dev);
- printk(KERN_INFO "Successfully removed RTC RV5C386A driver\n");
- }
- module_init(rtc_init);
- module_exit(rtc_exit);
- /*
- * Local Variables:
- * indent-tabs-mode:t
- * c-basic-offset:8
- * End:
- */
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