--- /dev/null
+/*
+ * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
+ *
+ * Copyright (C) 2005 James Chapman (ds1337 core)
+ * Copyright (C) 2006 David Brownell
+ * Copyright (C) 2009 Matthias Fuchs (rx8025 support)
+ * Copyright (C) 2012 Bertrand Achard (nvram access fixes)
+ *
+ * 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/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/string.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/rtc/ds1307.h>
+
+/*
+ * We can't determine type by probing, but if we expect pre-Linux code
+ * to have set the chip up as a clock (turning on the oscillator and
+ * setting the date and time), Linux can ignore the non-clock features.
+ * That's a natural job for a factory or repair bench.
+ */
+enum ds_type {
+ ds_1307,
+ ds_1337,
+ ds_1338,
+ ds_1339,
+ ds_1340,
+ ds_1388,
+ ds_3231,
+ m41t00,
+ mcp794xx,
+ rx_8025,
+ last_ds_type /* always last */
+ /* rs5c372 too? different address... */
+};
+
+
+/* RTC registers don't differ much, except for the century flag */
+#define DS1307_REG_SECS 0x00 /* 00-59 */
+# define DS1307_BIT_CH 0x80
+# define DS1340_BIT_nEOSC 0x80
+# define MCP794XX_BIT_ST 0x80
+#define DS1307_REG_MIN 0x01 /* 00-59 */
+#define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
+# define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
+# define DS1307_BIT_PM 0x20 /* in REG_HOUR */
+# define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
+# define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
+#define DS1307_REG_WDAY 0x03 /* 01-07 */
+# define MCP794XX_BIT_VBATEN 0x08
+#define DS1307_REG_MDAY 0x04 /* 01-31 */
+#define DS1307_REG_MONTH 0x05 /* 01-12 */
+# define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
+#define DS1307_REG_YEAR 0x06 /* 00-99 */
+
+/*
+ * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
+ * start at 7, and they differ a LOT. Only control and status matter for
+ * basic RTC date and time functionality; be careful using them.
+ */
+#define DS1307_REG_CONTROL 0x07 /* or ds1338 */
+# define DS1307_BIT_OUT 0x80
+# define DS1338_BIT_OSF 0x20
+# define DS1307_BIT_SQWE 0x10
+# define DS1307_BIT_RS1 0x02
+# define DS1307_BIT_RS0 0x01
+#define DS1337_REG_CONTROL 0x0e
+# define DS1337_BIT_nEOSC 0x80
+# define DS1339_BIT_BBSQI 0x20
+# define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
+# define DS1337_BIT_RS2 0x10
+# define DS1337_BIT_RS1 0x08
+# define DS1337_BIT_INTCN 0x04
+# define DS1337_BIT_A2IE 0x02
+# define DS1337_BIT_A1IE 0x01
+#define DS1340_REG_CONTROL 0x07
+# define DS1340_BIT_OUT 0x80
+# define DS1340_BIT_FT 0x40
+# define DS1340_BIT_CALIB_SIGN 0x20
+# define DS1340_M_CALIBRATION 0x1f
+#define DS1340_REG_FLAG 0x09
+# define DS1340_BIT_OSF 0x80
+#define DS1337_REG_STATUS 0x0f
+# define DS1337_BIT_OSF 0x80
+# define DS1337_BIT_A2I 0x02
+# define DS1337_BIT_A1I 0x01
+#define DS1339_REG_ALARM1_SECS 0x07
+
+#define DS13XX_TRICKLE_CHARGER_MAGIC 0xa0
+
+#define RX8025_REG_CTRL1 0x0e
+# define RX8025_BIT_2412 0x20
+#define RX8025_REG_CTRL2 0x0f
+# define RX8025_BIT_PON 0x10
+# define RX8025_BIT_VDET 0x40
+# define RX8025_BIT_XST 0x20
+
+
+struct ds1307 {
+ u8 offset; /* register's offset */
+ u8 regs[11];
+ u16 nvram_offset;
+ struct bin_attribute *nvram;
+ enum ds_type type;
+ unsigned long flags;
+#define HAS_NVRAM 0 /* bit 0 == sysfs file active */
+#define HAS_ALARM 1 /* bit 1 == irq claimed */
+ struct i2c_client *client;
+ struct rtc_device *rtc;
+ struct work_struct work;
+ s32 (*read_block_data)(const struct i2c_client *client, u8 command,
+ u8 length, u8 *values);
+ s32 (*write_block_data)(const struct i2c_client *client, u8 command,
+ u8 length, const u8 *values);
+};
+
+struct chip_desc {
+ unsigned alarm:1;
+ u16 nvram_offset;
+ u16 nvram_size;
+ u16 trickle_charger_reg;
+ u8 trickle_charger_setup;
+ u8 (*do_trickle_setup)(struct i2c_client *, uint32_t, bool);
+};
+
+static u8 do_trickle_setup_ds1339(struct i2c_client *,
+ uint32_t ohms, bool diode);
+
+static struct chip_desc chips[last_ds_type] = {
+ [ds_1307] = {
+ .nvram_offset = 8,
+ .nvram_size = 56,
+ },
+ [ds_1337] = {
+ .alarm = 1,
+ },
+ [ds_1338] = {
+ .nvram_offset = 8,
+ .nvram_size = 56,
+ },
+ [ds_1339] = {
+ .alarm = 1,
+ .trickle_charger_reg = 0x10,
+ .do_trickle_setup = &do_trickle_setup_ds1339,
+ },
+ [ds_1340] = {
+ .trickle_charger_reg = 0x08,
+ },
+ [ds_1388] = {
+ .trickle_charger_reg = 0x0a,
+ },
+ [ds_3231] = {
+ .alarm = 1,
+ },
+ [mcp794xx] = {
+ .alarm = 1,
+ /* this is battery backed SRAM */
+ .nvram_offset = 0x20,
+ .nvram_size = 0x40,
+ },
+};
+
+static const struct i2c_device_id ds1307_id[] = {
+ { "ds1307", ds_1307 },
+ { "ds1337", ds_1337 },
+ { "ds1338", ds_1338 },
+ { "ds1339", ds_1339 },
+ { "ds1388", ds_1388 },
+ { "ds1340", ds_1340 },
+ { "ds3231", ds_3231 },
+ { "m41t00", m41t00 },
+ { "mcp7940x", mcp794xx },
+ { "mcp7941x", mcp794xx },
+ { "pt7c4338", ds_1307 },
+ { "rx8025", rx_8025 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ds1307_id);
+
+/*----------------------------------------------------------------------*/
+
+#define BLOCK_DATA_MAX_TRIES 10
+
+static s32 ds1307_read_block_data_once(const struct i2c_client *client,
+ u8 command, u8 length, u8 *values)
+{
+ s32 i, data;
+
+ for (i = 0; i < length; i++) {
+ data = i2c_smbus_read_byte_data(client, command + i);
+ if (data < 0)
+ return data;
+ values[i] = data;
+ }
+ return i;
+}
+
+static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
+ u8 length, u8 *values)
+{
+ u8 oldvalues[255];
+ s32 ret;
+ int tries = 0;
+
+ dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
+ ret = ds1307_read_block_data_once(client, command, length, values);
+ if (ret < 0)
+ return ret;
+ do {
+ if (++tries > BLOCK_DATA_MAX_TRIES) {
+ dev_err(&client->dev,
+ "ds1307_read_block_data failed\n");
+ return -EIO;
+ }
+ memcpy(oldvalues, values, length);
+ ret = ds1307_read_block_data_once(client, command, length,
+ values);
+ if (ret < 0)
+ return ret;
+ } while (memcmp(oldvalues, values, length));
+ return length;
+}
+
+static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
+ u8 length, const u8 *values)
+{
+ u8 currvalues[255];
+ int tries = 0;
+
+ dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
+ do {
+ s32 i, ret;
+
+ if (++tries > BLOCK_DATA_MAX_TRIES) {
+ dev_err(&client->dev,
+ "ds1307_write_block_data failed\n");
+ return -EIO;
+ }
+ for (i = 0; i < length; i++) {
+ ret = i2c_smbus_write_byte_data(client, command + i,
+ values[i]);
+ if (ret < 0)
+ return ret;
+ }
+ ret = ds1307_read_block_data_once(client, command, length,
+ currvalues);
+ if (ret < 0)
+ return ret;
+ } while (memcmp(currvalues, values, length));
+ return length;
+}
+
+/*----------------------------------------------------------------------*/
+
+/* These RTC devices are not designed to be connected to a SMbus adapter.
+ SMbus limits block operations length to 32 bytes, whereas it's not
+ limited on I2C buses. As a result, accesses may exceed 32 bytes;
+ in that case, split them into smaller blocks */
+
+static s32 ds1307_native_smbus_write_block_data(const struct i2c_client *client,
+ u8 command, u8 length, const u8 *values)
+{
+ u8 suboffset = 0;
+
+ if (length <= I2C_SMBUS_BLOCK_MAX)
+ return i2c_smbus_write_i2c_block_data(client,
+ command, length, values);
+
+ while (suboffset < length) {
+ s32 retval = i2c_smbus_write_i2c_block_data(client,
+ command + suboffset,
+ min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
+ values + suboffset);
+ if (retval < 0)
+ return retval;
+
+ suboffset += I2C_SMBUS_BLOCK_MAX;
+ }
+ return length;
+}
+
+static s32 ds1307_native_smbus_read_block_data(const struct i2c_client *client,
+ u8 command, u8 length, u8 *values)
+{
+ u8 suboffset = 0;
+
+ if (length <= I2C_SMBUS_BLOCK_MAX)
+ return i2c_smbus_read_i2c_block_data(client,
+ command, length, values);
+
+ while (suboffset < length) {
+ s32 retval = i2c_smbus_read_i2c_block_data(client,
+ command + suboffset,
+ min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
+ values + suboffset);
+ if (retval < 0)
+ return retval;
+
+ suboffset += I2C_SMBUS_BLOCK_MAX;
+ }
+ return length;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * The IRQ logic includes a "real" handler running in IRQ context just
+ * long enough to schedule this workqueue entry. We need a task context
+ * to talk to the RTC, since I2C I/O calls require that; and disable the
+ * IRQ until we clear its status on the chip, so that this handler can
+ * work with any type of triggering (not just falling edge).
+ *
+ * The ds1337 and ds1339 both have two alarms, but we only use the first
+ * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
+ * signal; ds1339 chips have only one alarm signal.
+ */
+static void ds1307_work(struct work_struct *work)
+{
+ struct ds1307 *ds1307;
+ struct i2c_client *client;
+ struct mutex *lock;
+ int stat, control;
+
+ ds1307 = container_of(work, struct ds1307, work);
+ client = ds1307->client;
+ lock = &ds1307->rtc->ops_lock;
+
+ mutex_lock(lock);
+ stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
+ if (stat < 0)
+ goto out;
+
+ if (stat & DS1337_BIT_A1I) {
+ stat &= ~DS1337_BIT_A1I;
+ i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
+
+ control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
+ if (control < 0)
+ goto out;
+
+ control &= ~DS1337_BIT_A1IE;
+ i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
+
+ rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
+ }
+
+out:
+ if (test_bit(HAS_ALARM, &ds1307->flags))
+ enable_irq(client->irq);
+ mutex_unlock(lock);
+}
+
+static irqreturn_t ds1307_irq(int irq, void *dev_id)
+{
+ struct i2c_client *client = dev_id;
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+
+ disable_irq_nosync(irq);
+ schedule_work(&ds1307->work);
+ return IRQ_HANDLED;
+}
+
+/*----------------------------------------------------------------------*/
+
+static int ds1307_get_time(struct device *dev, struct rtc_time *t)
+{
+ struct ds1307 *ds1307 = dev_get_drvdata(dev);
+ int tmp;
+
+ /* read the RTC date and time registers all at once */
+ tmp = ds1307->read_block_data(ds1307->client,
+ ds1307->offset, 7, ds1307->regs);
+ if (tmp != 7) {
+ dev_err(dev, "%s error %d\n", "read", tmp);
+ return -EIO;
+ }
+
+ dev_dbg(dev, "%s: %7ph\n", "read", ds1307->regs);
+
+ t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
+ t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
+ tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
+ t->tm_hour = bcd2bin(tmp);
+ t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
+ t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
+ tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
+ t->tm_mon = bcd2bin(tmp) - 1;
+
+ /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
+ t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
+
+ dev_dbg(dev, "%s secs=%d, mins=%d, "
+ "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
+ "read", t->tm_sec, t->tm_min,
+ t->tm_hour, t->tm_mday,
+ t->tm_mon, t->tm_year, t->tm_wday);
+
+ /* initial clock setting can be undefined */
+ return rtc_valid_tm(t);
+}
+
+static int ds1307_set_time(struct device *dev, struct rtc_time *t)
+{
+ struct ds1307 *ds1307 = dev_get_drvdata(dev);
+ int result;
+ int tmp;
+ u8 *buf = ds1307->regs;
+
+ dev_dbg(dev, "%s secs=%d, mins=%d, "
+ "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
+ "write", t->tm_sec, t->tm_min,
+ t->tm_hour, t->tm_mday,
+ t->tm_mon, t->tm_year, t->tm_wday);
+
+ buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
+ buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
+ buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
+ buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
+ buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
+ buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
+
+ /* assume 20YY not 19YY */
+ tmp = t->tm_year - 100;
+ buf[DS1307_REG_YEAR] = bin2bcd(tmp);
+
+ switch (ds1307->type) {
+ case ds_1337:
+ case ds_1339:
+ case ds_3231:
+ buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
+ break;
+ case ds_1340:
+ buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
+ | DS1340_BIT_CENTURY;
+ break;
+ case mcp794xx:
+ /*
+ * these bits were cleared when preparing the date/time
+ * values and need to be set again before writing the
+ * buffer out to the device.
+ */
+ buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
+ buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
+ break;
+ default:
+ break;
+ }
+
+ dev_dbg(dev, "%s: %7ph\n", "write", buf);
+
+ result = ds1307->write_block_data(ds1307->client,
+ ds1307->offset, 7, buf);
+ if (result < 0) {
+ dev_err(dev, "%s error %d\n", "write", result);
+ return result;
+ }
+ return 0;
+}
+
+static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ int ret;
+
+ if (!test_bit(HAS_ALARM, &ds1307->flags))
+ return -EINVAL;
+
+ /* read all ALARM1, ALARM2, and status registers at once */
+ ret = ds1307->read_block_data(client,
+ DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
+ if (ret != 9) {
+ dev_err(dev, "%s error %d\n", "alarm read", ret);
+ return -EIO;
+ }
+
+ dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
+ "alarm read",
+ ds1307->regs[0], ds1307->regs[1],
+ ds1307->regs[2], ds1307->regs[3],
+ ds1307->regs[4], ds1307->regs[5],
+ ds1307->regs[6], ds1307->regs[7],
+ ds1307->regs[8]);
+
+ /*
+ * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
+ * and that all four fields are checked matches
+ */
+ t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
+ t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
+ t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
+ t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
+ 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 = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
+ t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
+
+ dev_dbg(dev, "%s secs=%d, mins=%d, "
+ "hours=%d, mday=%d, enabled=%d, pending=%d\n",
+ "alarm read", t->time.tm_sec, t->time.tm_min,
+ t->time.tm_hour, t->time.tm_mday,
+ t->enabled, t->pending);
+
+ return 0;
+}
+
+static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ unsigned char *buf = ds1307->regs;
+ u8 control, status;
+ int ret;
+
+ if (!test_bit(HAS_ALARM, &ds1307->flags))
+ return -EINVAL;
+
+ dev_dbg(dev, "%s secs=%d, mins=%d, "
+ "hours=%d, mday=%d, enabled=%d, pending=%d\n",
+ "alarm set", t->time.tm_sec, t->time.tm_min,
+ t->time.tm_hour, t->time.tm_mday,
+ t->enabled, t->pending);
+
+ /* read current status of both alarms and the chip */
+ ret = ds1307->read_block_data(client,
+ DS1339_REG_ALARM1_SECS, 9, buf);
+ if (ret != 9) {
+ dev_err(dev, "%s error %d\n", "alarm write", ret);
+ return -EIO;
+ }
+ control = ds1307->regs[7];
+ status = ds1307->regs[8];
+
+ dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
+ "alarm set (old status)",
+ ds1307->regs[0], ds1307->regs[1],
+ ds1307->regs[2], ds1307->regs[3],
+ ds1307->regs[4], ds1307->regs[5],
+ ds1307->regs[6], control, status);
+
+ /* set ALARM1, using 24 hour and day-of-month modes */
+ buf[0] = bin2bcd(t->time.tm_sec);
+ buf[1] = bin2bcd(t->time.tm_min);
+ buf[2] = bin2bcd(t->time.tm_hour);
+ buf[3] = bin2bcd(t->time.tm_mday);
+
+ /* set ALARM2 to non-garbage */
+ buf[4] = 0;
+ buf[5] = 0;
+ buf[6] = 0;
+
+ /* optionally enable ALARM1 */
+ buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
+ if (t->enabled) {
+ dev_dbg(dev, "alarm IRQ armed\n");
+ buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
+ }
+ buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
+
+ ret = ds1307->write_block_data(client,
+ DS1339_REG_ALARM1_SECS, 9, buf);
+ if (ret < 0) {
+ dev_err(dev, "can't set alarm time\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ int ret;
+
+ if (!test_bit(HAS_ALARM, &ds1307->flags))
+ return -ENOTTY;
+
+ ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
+ if (ret < 0)
+ return ret;
+
+ if (enabled)
+ ret |= DS1337_BIT_A1IE;
+ else
+ ret &= ~DS1337_BIT_A1IE;
+
+ ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static const struct rtc_class_ops ds13xx_rtc_ops = {
+ .read_time = ds1307_get_time,
+ .set_time = ds1307_set_time,
+ .read_alarm = ds1337_read_alarm,
+ .set_alarm = ds1337_set_alarm,
+ .alarm_irq_enable = ds1307_alarm_irq_enable,
+};
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * Alarm support for mcp794xx devices.
+ */
+
+#define MCP794XX_REG_CONTROL 0x07
+# define MCP794XX_BIT_ALM0_EN 0x10
+# define MCP794XX_BIT_ALM1_EN 0x20
+#define MCP794XX_REG_ALARM0_BASE 0x0a
+#define MCP794XX_REG_ALARM0_CTRL 0x0d
+#define MCP794XX_REG_ALARM1_BASE 0x11
+#define MCP794XX_REG_ALARM1_CTRL 0x14
+# define MCP794XX_BIT_ALMX_IF (1 << 3)
+# define MCP794XX_BIT_ALMX_C0 (1 << 4)
+# define MCP794XX_BIT_ALMX_C1 (1 << 5)
+# define MCP794XX_BIT_ALMX_C2 (1 << 6)
+# define MCP794XX_BIT_ALMX_POL (1 << 7)
+# define MCP794XX_MSK_ALMX_MATCH (MCP794XX_BIT_ALMX_C0 | \
+ MCP794XX_BIT_ALMX_C1 | \
+ MCP794XX_BIT_ALMX_C2)
+
+static void mcp794xx_work(struct work_struct *work)
+{
+ struct ds1307 *ds1307 = container_of(work, struct ds1307, work);
+ struct i2c_client *client = ds1307->client;
+ int reg, ret;
+
+ mutex_lock(&ds1307->rtc->ops_lock);
+
+ /* Check and clear alarm 0 interrupt flag. */
+ reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_ALARM0_CTRL);
+ if (reg < 0)
+ goto out;
+ if (!(reg & MCP794XX_BIT_ALMX_IF))
+ goto out;
+ reg &= ~MCP794XX_BIT_ALMX_IF;
+ ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_ALARM0_CTRL, reg);
+ if (ret < 0)
+ goto out;
+
+ /* Disable alarm 0. */
+ reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
+ if (reg < 0)
+ goto out;
+ reg &= ~MCP794XX_BIT_ALM0_EN;
+ ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
+ if (ret < 0)
+ goto out;
+
+ rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
+
+out:
+ if (test_bit(HAS_ALARM, &ds1307->flags))
+ enable_irq(client->irq);
+ mutex_unlock(&ds1307->rtc->ops_lock);
+}
+
+static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ u8 *regs = ds1307->regs;
+ int ret;
+
+ if (!test_bit(HAS_ALARM, &ds1307->flags))
+ return -EINVAL;
+
+ /* Read control and alarm 0 registers. */
+ ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
+ if (ret < 0)
+ return ret;
+
+ t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
+
+ /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
+ t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
+ t->time.tm_min = bcd2bin(ds1307->regs[4] & 0x7f);
+ t->time.tm_hour = bcd2bin(ds1307->regs[5] & 0x3f);
+ t->time.tm_wday = bcd2bin(ds1307->regs[6] & 0x7) - 1;
+ t->time.tm_mday = bcd2bin(ds1307->regs[7] & 0x3f);
+ t->time.tm_mon = bcd2bin(ds1307->regs[8] & 0x1f) - 1;
+ t->time.tm_year = -1;
+ t->time.tm_yday = -1;
+ t->time.tm_isdst = -1;
+
+ dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
+ "enabled=%d polarity=%d irq=%d match=%d\n", __func__,
+ t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
+ t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
+ !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
+ !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
+ (ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
+
+ return 0;
+}
+
+static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ unsigned char *regs = ds1307->regs;
+ int ret;
+
+ if (!test_bit(HAS_ALARM, &ds1307->flags))
+ return -EINVAL;
+
+ dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
+ "enabled=%d pending=%d\n", __func__,
+ t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
+ t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
+ t->enabled, t->pending);
+
+ /* Read control and alarm 0 registers. */
+ ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
+ if (ret < 0)
+ return ret;
+
+ /* Set alarm 0, using 24-hour and day-of-month modes. */
+ regs[3] = bin2bcd(t->time.tm_sec);
+ regs[4] = bin2bcd(t->time.tm_min);
+ regs[5] = bin2bcd(t->time.tm_hour);
+ regs[6] = bin2bcd(t->time.tm_wday) + 1;
+ regs[7] = bin2bcd(t->time.tm_mday);
+ regs[8] = bin2bcd(t->time.tm_mon) + 1;
+
+ /* Clear the alarm 0 interrupt flag. */
+ regs[6] &= ~MCP794XX_BIT_ALMX_IF;
+ /* Set alarm match: second, minute, hour, day, date, month. */
+ regs[6] |= MCP794XX_MSK_ALMX_MATCH;
+
+ if (t->enabled)
+ regs[0] |= MCP794XX_BIT_ALM0_EN;
+ else
+ regs[0] &= ~MCP794XX_BIT_ALM0_EN;
+
+ ret = ds1307->write_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ int reg;
+
+ if (!test_bit(HAS_ALARM, &ds1307->flags))
+ return -EINVAL;
+
+ reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
+ if (reg < 0)
+ return reg;
+
+ if (enabled)
+ reg |= MCP794XX_BIT_ALM0_EN;
+ else
+ reg &= ~MCP794XX_BIT_ALM0_EN;
+
+ return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
+}
+
+static const struct rtc_class_ops mcp794xx_rtc_ops = {
+ .read_time = ds1307_get_time,
+ .set_time = ds1307_set_time,
+ .read_alarm = mcp794xx_read_alarm,
+ .set_alarm = mcp794xx_set_alarm,
+ .alarm_irq_enable = mcp794xx_alarm_irq_enable,
+};
+
+/*----------------------------------------------------------------------*/
+
+static ssize_t
+ds1307_nvram_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *attr,
+ char *buf, loff_t off, size_t count)
+{
+ struct i2c_client *client;
+ struct ds1307 *ds1307;
+ int result;
+
+ client = kobj_to_i2c_client(kobj);
+ ds1307 = i2c_get_clientdata(client);
+
+ if (unlikely(off >= ds1307->nvram->size))
+ return 0;
+ if ((off + count) > ds1307->nvram->size)
+ count = ds1307->nvram->size - off;
+ if (unlikely(!count))
+ return count;
+
+ result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
+ count, buf);
+ if (result < 0)
+ dev_err(&client->dev, "%s error %d\n", "nvram read", result);
+ return result;
+}
+
+static ssize_t
+ds1307_nvram_write(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *attr,
+ char *buf, loff_t off, size_t count)
+{
+ struct i2c_client *client;
+ struct ds1307 *ds1307;
+ int result;
+
+ client = kobj_to_i2c_client(kobj);
+ ds1307 = i2c_get_clientdata(client);
+
+ if (unlikely(off >= ds1307->nvram->size))
+ return -EFBIG;
+ if ((off + count) > ds1307->nvram->size)
+ count = ds1307->nvram->size - off;
+ if (unlikely(!count))
+ return count;
+
+ result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
+ count, buf);
+ if (result < 0) {
+ dev_err(&client->dev, "%s error %d\n", "nvram write", result);
+ return result;
+ }
+ return count;
+}
+
+
+/*----------------------------------------------------------------------*/
+
+static u8 do_trickle_setup_ds1339(struct i2c_client *client,
+ uint32_t ohms, bool diode)
+{
+ u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
+ DS1307_TRICKLE_CHARGER_NO_DIODE;
+
+ switch (ohms) {
+ case 250:
+ setup |= DS1307_TRICKLE_CHARGER_250_OHM;
+ break;
+ case 2000:
+ setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
+ break;
+ case 4000:
+ setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
+ break;
+ default:
+ dev_warn(&client->dev,
+ "Unsupported ohm value %u in dt\n", ohms);
+ return 0;
+ }
+ return setup;
+}
+
+static void ds1307_trickle_of_init(struct i2c_client *client,
+ struct chip_desc *chip)
+{
+ uint32_t ohms = 0;
+ bool diode = true;
+
+ if (!chip->do_trickle_setup)
+ goto out;
+ if (of_property_read_u32(client->dev.of_node, "trickle-resistor-ohms" , &ohms))
+ goto out;
+ if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable"))
+ diode = false;
+ chip->trickle_charger_setup = chip->do_trickle_setup(client,
+ ohms, diode);
+out:
+ return;
+}
+
+static int ds1307_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct ds1307 *ds1307;
+ int err = -ENODEV;
+ int tmp;
+ struct chip_desc *chip = &chips[id->driver_data];
+ struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+ bool want_irq = false;
+ unsigned char *buf;
+ struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
+ static const int bbsqi_bitpos[] = {
+ [ds_1337] = 0,
+ [ds_1339] = DS1339_BIT_BBSQI,
+ [ds_3231] = DS3231_BIT_BBSQW,
+ };
+ const struct rtc_class_ops *rtc_ops = &ds13xx_rtc_ops;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
+ && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
+ return -EIO;
+
+ ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
+ if (!ds1307)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, ds1307);
+
+ ds1307->client = client;
+ ds1307->type = id->driver_data;
+
+ if (!pdata && client->dev.of_node)
+ ds1307_trickle_of_init(client, chip);
+ else if (pdata && pdata->trickle_charger_setup)
+ chip->trickle_charger_setup = pdata->trickle_charger_setup;
+
+ if (chip->trickle_charger_setup && chip->trickle_charger_reg) {
+ dev_dbg(&client->dev, "writing trickle charger info 0x%x to 0x%x\n",
+ DS13XX_TRICKLE_CHARGER_MAGIC | chip->trickle_charger_setup,
+ chip->trickle_charger_reg);
+ i2c_smbus_write_byte_data(client, chip->trickle_charger_reg,
+ DS13XX_TRICKLE_CHARGER_MAGIC |
+ chip->trickle_charger_setup);
+ }
+
+ buf = ds1307->regs;
+ if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
+ ds1307->read_block_data = ds1307_native_smbus_read_block_data;
+ ds1307->write_block_data = ds1307_native_smbus_write_block_data;
+ } else {
+ ds1307->read_block_data = ds1307_read_block_data;
+ ds1307->write_block_data = ds1307_write_block_data;
+ }
+
+ switch (ds1307->type) {
+ case ds_1337:
+ case ds_1339:
+ case ds_3231:
+ /* get registers that the "rtc" read below won't read... */
+ tmp = ds1307->read_block_data(ds1307->client,
+ DS1337_REG_CONTROL, 2, buf);
+ if (tmp != 2) {
+ dev_dbg(&client->dev, "read error %d\n", tmp);
+ err = -EIO;
+ goto exit;
+ }
+
+ /* oscillator off? turn it on, so clock can tick. */
+ if (ds1307->regs[0] & DS1337_BIT_nEOSC)
+ ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
+
+ /*
+ * Using IRQ? Disable the square wave and both alarms.
+ * For some variants, be sure alarms can trigger when we're
+ * running on Vbackup (BBSQI/BBSQW)
+ */
+ if (ds1307->client->irq > 0 && chip->alarm) {
+ INIT_WORK(&ds1307->work, ds1307_work);
+
+ ds1307->regs[0] |= DS1337_BIT_INTCN
+ | bbsqi_bitpos[ds1307->type];
+ ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
+
+ want_irq = true;
+ }
+
+ i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
+ ds1307->regs[0]);
+
+ /* oscillator fault? clear flag, and warn */
+ if (ds1307->regs[1] & DS1337_BIT_OSF) {
+ i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
+ ds1307->regs[1] & ~DS1337_BIT_OSF);
+ dev_warn(&client->dev, "SET TIME!\n");
+ }
+ break;
+
+ case rx_8025:
+ tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
+ RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
+ if (tmp != 2) {
+ dev_dbg(&client->dev, "read error %d\n", tmp);
+ err = -EIO;
+ goto exit;
+ }
+
+ /* oscillator off? turn it on, so clock can tick. */
+ if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
+ ds1307->regs[1] |= RX8025_BIT_XST;
+ i2c_smbus_write_byte_data(client,
+ RX8025_REG_CTRL2 << 4 | 0x08,
+ ds1307->regs[1]);
+ dev_warn(&client->dev,
+ "oscillator stop detected - SET TIME!\n");
+ }
+
+ if (ds1307->regs[1] & RX8025_BIT_PON) {
+ ds1307->regs[1] &= ~RX8025_BIT_PON;
+ i2c_smbus_write_byte_data(client,
+ RX8025_REG_CTRL2 << 4 | 0x08,
+ ds1307->regs[1]);
+ dev_warn(&client->dev, "power-on detected\n");
+ }
+
+ if (ds1307->regs[1] & RX8025_BIT_VDET) {
+ ds1307->regs[1] &= ~RX8025_BIT_VDET;
+ i2c_smbus_write_byte_data(client,
+ RX8025_REG_CTRL2 << 4 | 0x08,
+ ds1307->regs[1]);
+ dev_warn(&client->dev, "voltage drop detected\n");
+ }
+
+ /* make sure we are running in 24hour mode */
+ if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
+ u8 hour;
+
+ /* switch to 24 hour mode */
+ i2c_smbus_write_byte_data(client,
+ RX8025_REG_CTRL1 << 4 | 0x08,
+ ds1307->regs[0] |
+ RX8025_BIT_2412);
+
+ tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
+ RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
+ if (tmp != 2) {
+ dev_dbg(&client->dev, "read error %d\n", tmp);
+ err = -EIO;
+ goto exit;
+ }
+
+ /* correct hour */
+ hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
+ if (hour == 12)
+ hour = 0;
+ if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
+ hour += 12;
+
+ i2c_smbus_write_byte_data(client,
+ DS1307_REG_HOUR << 4 | 0x08,
+ hour);
+ }
+ break;
+ case ds_1388:
+ ds1307->offset = 1; /* Seconds starts at 1 */
+ break;
+ case mcp794xx:
+ rtc_ops = &mcp794xx_rtc_ops;
+ if (ds1307->client->irq > 0 && chip->alarm) {
+ INIT_WORK(&ds1307->work, mcp794xx_work);
+ want_irq = true;
+ }
+ break;
+ default:
+ break;
+ }
+
+read_rtc:
+ /* read RTC registers */
+ tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
+ if (tmp != 8) {
+ dev_dbg(&client->dev, "read error %d\n", tmp);
+ err = -EIO;
+ goto exit;
+ }
+
+ /*
+ * minimal sanity checking; some chips (like DS1340) don't
+ * specify the extra bits as must-be-zero, but there are
+ * still a few values that are clearly out-of-range.
+ */
+ tmp = ds1307->regs[DS1307_REG_SECS];
+ switch (ds1307->type) {
+ case ds_1307:
+ case m41t00:
+ /* clock halted? turn it on, so clock can tick. */
+ if (tmp & DS1307_BIT_CH) {
+ i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
+ dev_warn(&client->dev, "SET TIME!\n");
+ goto read_rtc;
+ }
+ break;
+ case ds_1338:
+ /* clock halted? turn it on, so clock can tick. */
+ if (tmp & DS1307_BIT_CH)
+ i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
+
+ /* oscillator fault? clear flag, and warn */
+ if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
+ i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
+ ds1307->regs[DS1307_REG_CONTROL]
+ & ~DS1338_BIT_OSF);
+ dev_warn(&client->dev, "SET TIME!\n");
+ goto read_rtc;
+ }
+ break;
+ case ds_1340:
+ /* clock halted? turn it on, so clock can tick. */
+ if (tmp & DS1340_BIT_nEOSC)
+ i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
+
+ tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
+ if (tmp < 0) {
+ dev_dbg(&client->dev, "read error %d\n", tmp);
+ err = -EIO;
+ goto exit;
+ }
+
+ /* oscillator fault? clear flag, and warn */
+ if (tmp & DS1340_BIT_OSF) {
+ i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
+ dev_warn(&client->dev, "SET TIME!\n");
+ }
+ break;
+ case mcp794xx:
+ /* make sure that the backup battery is enabled */
+ if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
+ i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
+ ds1307->regs[DS1307_REG_WDAY]
+ | MCP794XX_BIT_VBATEN);
+ }
+
+ /* clock halted? turn it on, so clock can tick. */
+ if (!(tmp & MCP794XX_BIT_ST)) {
+ i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
+ MCP794XX_BIT_ST);
+ dev_warn(&client->dev, "SET TIME!\n");
+ goto read_rtc;
+ }
+
+ break;
+ default:
+ break;
+ }
+
+ tmp = ds1307->regs[DS1307_REG_HOUR];
+ switch (ds1307->type) {
+ case ds_1340:
+ case m41t00:
+ /*
+ * NOTE: ignores century bits; fix before deploying
+ * systems that will run through year 2100.
+ */
+ break;
+ case rx_8025:
+ break;
+ default:
+ if (!(tmp & DS1307_BIT_12HR))
+ break;
+
+ /*
+ * Be sure we're in 24 hour mode. Multi-master systems
+ * take note...
+ */
+ tmp = bcd2bin(tmp & 0x1f);
+ if (tmp == 12)
+ tmp = 0;
+ if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
+ tmp += 12;
+ i2c_smbus_write_byte_data(client,
+ ds1307->offset + DS1307_REG_HOUR,
+ bin2bcd(tmp));
+ }
+
+ device_set_wakeup_capable(&client->dev, want_irq);
+ ds1307->rtc = devm_rtc_device_register(&client->dev, client->name,
+ rtc_ops, THIS_MODULE);
+ if (IS_ERR(ds1307->rtc)) {
+ return PTR_ERR(ds1307->rtc);
+ }
+
+ if (want_irq) {
+ err = request_irq(client->irq, ds1307_irq, IRQF_SHARED,
+ ds1307->rtc->name, client);
+ if (err) {
+ client->irq = 0;
+ dev_err(&client->dev, "unable to request IRQ!\n");
+ } else {
+
+ set_bit(HAS_ALARM, &ds1307->flags);
+ dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
+ }
+ }
+
+ if (chip->nvram_size) {
+
+ ds1307->nvram = devm_kzalloc(&client->dev,
+ sizeof(struct bin_attribute),
+ GFP_KERNEL);
+ if (!ds1307->nvram) {
+ dev_err(&client->dev, "cannot allocate memory for nvram sysfs\n");
+ } else {
+
+ ds1307->nvram->attr.name = "nvram";
+ ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
+
+ sysfs_bin_attr_init(ds1307->nvram);
+
+ ds1307->nvram->read = ds1307_nvram_read;
+ ds1307->nvram->write = ds1307_nvram_write;
+ ds1307->nvram->size = chip->nvram_size;
+ ds1307->nvram_offset = chip->nvram_offset;
+
+ err = sysfs_create_bin_file(&client->dev.kobj,
+ ds1307->nvram);
+ if (err) {
+ dev_err(&client->dev,
+ "unable to create sysfs file: %s\n",
+ ds1307->nvram->attr.name);
+ } else {
+ set_bit(HAS_NVRAM, &ds1307->flags);
+ dev_info(&client->dev, "%zu bytes nvram\n",
+ ds1307->nvram->size);
+ }
+ }
+ }
+
+ return 0;
+
+exit:
+ return err;
+}
+
+static int ds1307_remove(struct i2c_client *client)
+{
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+
+ if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
+ free_irq(client->irq, client);
+ cancel_work_sync(&ds1307->work);
+ }
+
+ if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
+ sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);
+
+ return 0;
+}
+
+static struct i2c_driver ds1307_driver = {
+ .driver = {
+ .name = "rtc-ds1307",
+ .owner = THIS_MODULE,
+ },
+ .probe = ds1307_probe,
+ .remove = ds1307_remove,
+ .id_table = ds1307_id,
+};
+
+module_i2c_driver(ds1307_driver);
+
+MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff