/* * An I2C driver for Ricoh RS5C372 and RV5C38[67] RTCs * * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net> * Copyright (C) 2006 Tower Technologies * * 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. */ #include <linux/i2c.h> #include <linux/rtc.h> #include <linux/bcd.h> #define DRV_VERSION "0.5" /* * Ricoh has a family of I2C based RTCs, which differ only slightly from * each other. Differences center on pinout (e.g. how many interrupts, * output clock, etc) and how the control registers are used. The '372 * is significant only because that's the one this driver first supported. */ #define RS5C372_REG_SECS 0 #define RS5C372_REG_MINS 1 #define RS5C372_REG_HOURS 2 #define RS5C372_REG_WDAY 3 #define RS5C372_REG_DAY 4 #define RS5C372_REG_MONTH 5 #define RS5C372_REG_YEAR 6 #define RS5C372_REG_TRIM 7 # define RS5C372_TRIM_XSL 0x80 # define RS5C372_TRIM_MASK 0x7F #define RS5C_REG_ALARM_A_MIN 8 /* or ALARM_W */ #define RS5C_REG_ALARM_A_HOURS 9 #define RS5C_REG_ALARM_A_WDAY 10 #define RS5C_REG_ALARM_B_MIN 11 /* or ALARM_D */ #define RS5C_REG_ALARM_B_HOURS 12 #define RS5C_REG_ALARM_B_WDAY 13 /* (ALARM_B only) */ #define RS5C_REG_CTRL1 14 # define RS5C_CTRL1_AALE (1 << 7) /* or WALE */ # define RS5C_CTRL1_BALE (1 << 6) /* or DALE */ # define RV5C387_CTRL1_24 (1 << 5) # define RS5C372A_CTRL1_SL1 (1 << 5) # define RS5C_CTRL1_CT_MASK (7 << 0) # define RS5C_CTRL1_CT0 (0 << 0) /* no periodic irq */ # define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */ #define RS5C_REG_CTRL2 15 # define RS5C372_CTRL2_24 (1 << 5) # define RS5C_CTRL2_XSTP (1 << 4) # define RS5C_CTRL2_CTFG (1 << 2) # define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */ # define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */ /* to read (style 1) or write registers starting at R */ #define RS5C_ADDR(R) (((R) << 4) | 0) enum rtc_type { rtc_undef = 0, rtc_rs5c372a, rtc_rs5c372b, rtc_rv5c386, rtc_rv5c387a, }; /* REVISIT: this assumes that: * - we're in the 21st century, so it's safe to ignore the century * bit for rv5c38[67] (REG_MONTH bit 7); * - we should use ALARM_A not ALARM_B (may be wrong on some boards) */ struct rs5c372 { struct i2c_client *client; struct rtc_device *rtc; enum rtc_type type; unsigned time24:1; unsigned has_irq:1; char buf[17]; char *regs; }; static int rs5c_get_regs(struct rs5c372 *rs5c) { struct i2c_client *client = rs5c->client; struct i2c_msg msgs[] = { { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf }, }; /* This implements the third reading method from the datasheet, using * an internal address that's reset after each transaction (by STOP) * to 0x0f ... so we read extra registers, and skip the first one. * * The first method doesn't work with the iop3xx adapter driver, on at * least 80219 chips; this works around that bug. */ if ((i2c_transfer(client->adapter, msgs, 1)) != 1) { pr_debug("%s: can't read registers\n", rs5c->rtc->name); return -EIO; } dev_dbg(&client->dev, "%02x %02x %02x (%02x) %02x %02x %02x (%02x), " "%02x %02x %02x, %02x %02x %02x; %02x %02x\n", rs5c->regs[0], rs5c->regs[1], rs5c->regs[2], rs5c->regs[3], rs5c->regs[4], rs5c->regs[5], rs5c->regs[6], rs5c->regs[7], rs5c->regs[8], rs5c->regs[9], rs5c->regs[10], rs5c->regs[11], rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]); return 0; } static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg) { unsigned hour; if (rs5c->time24) return BCD2BIN(reg & 0x3f); hour = BCD2BIN(reg & 0x1f); if (hour == 12) hour = 0; if (reg & 0x20) hour += 12; return hour; } static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour) { if (rs5c->time24) return BIN2BCD(hour); if (hour > 12) return 0x20 | BIN2BCD(hour - 12); if (hour == 12) return 0x20 | BIN2BCD(12); if (hour == 0) return BIN2BCD(12); return BIN2BCD(hour); } static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm) { struct rs5c372 *rs5c = i2c_get_clientdata(client); int status = rs5c_get_regs(rs5c); if (status < 0) return status; tm->tm_sec = BCD2BIN(rs5c->regs[RS5C372_REG_SECS] & 0x7f); tm->tm_min = BCD2BIN(rs5c->regs[RS5C372_REG_MINS] & 0x7f); tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]); tm->tm_wday = BCD2BIN(rs5c->regs[RS5C372_REG_WDAY] & 0x07); tm->tm_mday = BCD2BIN(rs5c->regs[RS5C372_REG_DAY] & 0x3f); /* tm->tm_mon is zero-based */ tm->tm_mon = BCD2BIN(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1; /* year is 1900 + tm->tm_year */ tm->tm_year = BCD2BIN(rs5c->regs[RS5C372_REG_YEAR]) + 100; dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", __FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); /* rtc might need initialization */ return rtc_valid_tm(tm); } static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm) { struct rs5c372 *rs5c = i2c_get_clientdata(client); unsigned char buf[8]; dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d " "mday=%d, mon=%d, year=%d, wday=%d\n", __FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); buf[0] = RS5C_ADDR(RS5C372_REG_SECS); buf[1] = BIN2BCD(tm->tm_sec); buf[2] = BIN2BCD(tm->tm_min); buf[3] = rs5c_hr2reg(rs5c, tm->tm_hour); buf[4] = BIN2BCD(tm->tm_wday); buf[5] = BIN2BCD(tm->tm_mday); buf[6] = BIN2BCD(tm->tm_mon + 1); buf[7] = BIN2BCD(tm->tm_year - 100); if ((i2c_master_send(client, buf, 8)) != 8) { dev_err(&client->dev, "%s: write error\n", __FUNCTION__); return -EIO; } return 0; } #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE) #define NEED_TRIM #endif #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE) #define NEED_TRIM #endif #ifdef NEED_TRIM static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim) { struct rs5c372 *rs5c372 = i2c_get_clientdata(client); u8 tmp = rs5c372->regs[RS5C372_REG_TRIM]; if (osc) *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768; if (trim) { dev_dbg(&client->dev, "%s: raw trim=%x\n", __FUNCTION__, tmp); tmp &= RS5C372_TRIM_MASK; if (tmp & 0x3e) { int t = tmp & 0x3f; if (tmp & 0x40) t = (~t | (s8)0xc0) + 1; else t = t - 1; tmp = t * 2; } else tmp = 0; *trim = tmp; } return 0; } #endif static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm) { return rs5c372_get_datetime(to_i2c_client(dev), tm); } static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm) { return rs5c372_set_datetime(to_i2c_client(dev), tm); } #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE) static int rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { struct i2c_client *client = to_i2c_client(dev); struct rs5c372 *rs5c = i2c_get_clientdata(client); unsigned char buf[2]; int status; buf[1] = rs5c->regs[RS5C_REG_CTRL1]; switch (cmd) { case RTC_UIE_OFF: case RTC_UIE_ON: /* some 327a modes use a different IRQ pin for 1Hz irqs */ if (rs5c->type == rtc_rs5c372a && (buf[1] & RS5C372A_CTRL1_SL1)) return -ENOIOCTLCMD; case RTC_AIE_OFF: case RTC_AIE_ON: /* these irq management calls only make sense for chips * which are wired up to an IRQ. */ if (!rs5c->has_irq) return -ENOIOCTLCMD; break; default: return -ENOIOCTLCMD; } status = rs5c_get_regs(rs5c); if (status < 0) return status; buf[0] = RS5C_ADDR(RS5C_REG_CTRL1); switch (cmd) { case RTC_AIE_OFF: /* alarm off */ buf[1] &= ~RS5C_CTRL1_AALE; break; case RTC_AIE_ON: /* alarm on */ buf[1] |= RS5C_CTRL1_AALE; break; case RTC_UIE_OFF: /* update off */ buf[1] &= ~RS5C_CTRL1_CT_MASK; break; case RTC_UIE_ON: /* update on */ buf[1] &= ~RS5C_CTRL1_CT_MASK; buf[1] |= RS5C_CTRL1_CT4; break; } if ((i2c_master_send(client, buf, 2)) != 2) { printk(KERN_WARNING "%s: can't update alarm\n", rs5c->rtc->name); status = -EIO; } else rs5c->regs[RS5C_REG_CTRL1] = buf[1]; return status; } #else #define rs5c_rtc_ioctl NULL #endif /* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI, * which only exposes a polled programming interface; and since * these calls map directly to those EFI requests; we don't demand * we have an IRQ for this chip when we go through this API. * * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs * though, managed through RTC_AIE_{ON,OFF} requests. */ static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t) { struct i2c_client *client = to_i2c_client(dev); struct rs5c372 *rs5c = i2c_get_clientdata(client); int status; status = rs5c_get_regs(rs5c); if (status < 0) return status; /* report alarm time */ t->time.tm_sec = 0; t->time.tm_min = BCD2BIN(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f); t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]); t->time.tm_mday = -1; t->time.tm_mon = -1; t->time.tm_year = -1; t->time.tm_wday = -1; t->time.tm_yday = -1; t->time.tm_isdst = -1; /* ... and status */ t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE); t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG); return 0; } static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t) { struct i2c_client *client = to_i2c_client(dev); struct rs5c372 *rs5c = i2c_get_clientdata(client); int status; unsigned char buf[4]; /* only handle up to 24 hours in the future, like RTC_ALM_SET */ if (t->time.tm_mday != -1 || t->time.tm_mon != -1 || t->time.tm_year != -1) return -EINVAL; /* REVISIT: round up tm_sec */ /* if needed, disable irq (clears pending status) */ status = rs5c_get_regs(rs5c); if (status < 0) return status; if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) { buf[0] = RS5C_ADDR(RS5C_REG_CTRL1); buf[1] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE; if (i2c_master_send(client, buf, 2) != 2) { pr_debug("%s: can't disable alarm\n", rs5c->rtc->name); return -EIO; } rs5c->regs[RS5C_REG_CTRL1] = buf[1]; } /* set alarm */ buf[0] = RS5C_ADDR(RS5C_REG_ALARM_A_MIN); buf[1] = BIN2BCD(t->time.tm_min); buf[2] = rs5c_hr2reg(rs5c, t->time.tm_hour); buf[3] = 0x7f; /* any/all days */ if ((i2c_master_send(client, buf, 4)) != 4) { pr_debug("%s: can't set alarm time\n", rs5c->rtc->name); return -EIO; } /* ... and maybe enable its irq */ if (t->enabled) { buf[0] = RS5C_ADDR(RS5C_REG_CTRL1); buf[1] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE; if ((i2c_master_send(client, buf, 2)) != 2) printk(KERN_WARNING "%s: can't enable alarm\n", rs5c->rtc->name); rs5c->regs[RS5C_REG_CTRL1] = buf[1]; } return 0; } #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE) static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq) { int err, osc, trim; err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim); if (err == 0) { seq_printf(seq, "crystal\t\t: %d.%03d KHz\n", osc / 1000, osc % 1000); seq_printf(seq, "trim\t\t: %d\n", trim); } return 0; } #else #define rs5c372_rtc_proc NULL #endif static const struct rtc_class_ops rs5c372_rtc_ops = { .proc = rs5c372_rtc_proc, .ioctl = rs5c_rtc_ioctl, .read_time = rs5c372_rtc_read_time, .set_time = rs5c372_rtc_set_time, .read_alarm = rs5c_read_alarm, .set_alarm = rs5c_set_alarm, }; #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE) static ssize_t rs5c372_sysfs_show_trim(struct device *dev, struct device_attribute *attr, char *buf) { int err, trim; err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim); if (err) return err; return sprintf(buf, "%d\n", trim); } static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL); static ssize_t rs5c372_sysfs_show_osc(struct device *dev, struct device_attribute *attr, char *buf) { int err, osc; err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL); if (err) return err; return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000); } static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL); static int rs5c_sysfs_register(struct device *dev) { int err; err = device_create_file(dev, &dev_attr_trim); if (err) return err; err = device_create_file(dev, &dev_attr_osc); if (err) device_remove_file(dev, &dev_attr_trim); return err; } static void rs5c_sysfs_unregister(struct device *dev) { device_remove_file(dev, &dev_attr_trim); device_remove_file(dev, &dev_attr_osc); } #else static int rs5c_sysfs_register(struct device *dev) { return 0; } static void rs5c_sysfs_unregister(struct device *dev) { /* nothing */ } #endif /* SYSFS */ static struct i2c_driver rs5c372_driver; static int rs5c372_probe(struct i2c_client *client) { int err = 0; struct rs5c372 *rs5c372; struct rtc_time tm; dev_dbg(&client->dev, "%s\n", __FUNCTION__); if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { err = -ENODEV; goto exit; } if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) { err = -ENOMEM; goto exit; } /* we read registers 0x0f then 0x00-0x0f; skip the first one */ rs5c372->regs=&rs5c372->buf[1]; rs5c372->client = client; i2c_set_clientdata(client, rs5c372); err = rs5c_get_regs(rs5c372); if (err < 0) goto exit_kfree; if (strcmp(client->name, "rs5c372a") == 0) rs5c372->type = rtc_rs5c372a; else if (strcmp(client->name, "rs5c372b") == 0) rs5c372->type = rtc_rs5c372b; else if (strcmp(client->name, "rv5c386") == 0) rs5c372->type = rtc_rv5c386; else if (strcmp(client->name, "rv5c387a") == 0) rs5c372->type = rtc_rv5c387a; else { rs5c372->type = rtc_rs5c372b; dev_warn(&client->dev, "assuming rs5c372b\n"); } /* clock may be set for am/pm or 24 hr time */ switch (rs5c372->type) { case rtc_rs5c372a: case rtc_rs5c372b: /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b. * so does periodic irq, except some 327a modes. */ if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24) rs5c372->time24 = 1; break; case rtc_rv5c386: case rtc_rv5c387a: if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24) rs5c372->time24 = 1; /* alarm uses ALARM_W; and nINTRB for alarm and periodic * irq, on both 386 and 387 */ break; default: dev_err(&client->dev, "unknown RTC type\n"); goto exit_kfree; } /* if the oscillator lost power and no other software (like * the bootloader) set it up, do it here. */ if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP) { unsigned char buf[3]; rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP; buf[0] = RS5C_ADDR(RS5C_REG_CTRL1); buf[1] = rs5c372->regs[RS5C_REG_CTRL1]; buf[2] = rs5c372->regs[RS5C_REG_CTRL2]; /* use 24hr mode */ switch (rs5c372->type) { case rtc_rs5c372a: case rtc_rs5c372b: buf[2] |= RS5C372_CTRL2_24; rs5c372->time24 = 1; break; case rtc_rv5c386: case rtc_rv5c387a: buf[1] |= RV5C387_CTRL1_24; rs5c372->time24 = 1; break; default: /* impossible */ break; } if ((i2c_master_send(client, buf, 3)) != 3) { dev_err(&client->dev, "setup error\n"); goto exit_kfree; } rs5c372->regs[RS5C_REG_CTRL1] = buf[1]; rs5c372->regs[RS5C_REG_CTRL2] = buf[2]; } if (rs5c372_get_datetime(client, &tm) < 0) dev_warn(&client->dev, "clock needs to be set\n"); dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n", ({ char *s; switch (rs5c372->type) { case rtc_rs5c372a: s = "rs5c372a"; break; case rtc_rs5c372b: s = "rs5c372b"; break; case rtc_rv5c386: s = "rv5c386"; break; case rtc_rv5c387a: s = "rv5c387a"; break; default: s = "chip"; break; }; s;}), rs5c372->time24 ? "24hr" : "am/pm" ); /* REVISIT use client->irq to register alarm irq ... */ rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name, &client->dev, &rs5c372_rtc_ops, THIS_MODULE); if (IS_ERR(rs5c372->rtc)) { err = PTR_ERR(rs5c372->rtc); goto exit_kfree; } err = rs5c_sysfs_register(&client->dev); if (err) goto exit_devreg; return 0; exit_devreg: rtc_device_unregister(rs5c372->rtc); exit_kfree: kfree(rs5c372); exit: return err; } static int rs5c372_remove(struct i2c_client *client) { struct rs5c372 *rs5c372 = i2c_get_clientdata(client); rtc_device_unregister(rs5c372->rtc); rs5c_sysfs_unregister(&client->dev); kfree(rs5c372); return 0; } static struct i2c_driver rs5c372_driver = { .driver = { .name = "rtc-rs5c372", }, .probe = rs5c372_probe, .remove = rs5c372_remove, }; static __init int rs5c372_init(void) { return i2c_add_driver(&rs5c372_driver); } static __exit void rs5c372_exit(void) { i2c_del_driver(&rs5c372_driver); } module_init(rs5c372_init); module_exit(rs5c372_exit); MODULE_AUTHOR( "Pavel Mironchik <pmironchik@optifacio.net>, " "Alessandro Zummo <a.zummo@towertech.it>"); MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_VERSION);