Initial import

1 files changed, 696 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-x1205.c b/drivers/rtc/rtc-x1205.c
new file mode 100644
index 000000000..5638b7ba8
--- /dev/null
+++ b/drivers/rtc/rtc-x1205.c
@@ -0,0 +1,696 @@
+/*
+ * An i2c driver for the Xicor/Intersil X1205 RTC
+ * Copyright 2004 Karen Spearel
+ * Copyright 2005 Alessandro Zummo
+ *
+ * please send all reports to:
+ *	Karen Spearel <kas111 at gmail dot com>
+ *	Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * based on a lot of other RTC drivers.
+ *
+ * Information and datasheet:
+ * http://www.intersil.com/cda/deviceinfo/0,1477,X1205,00.html
+ *
+ * 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/bcd.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+
+#define DRV_VERSION "1.0.8"
+
+/* offsets into CCR area */
+
+#define CCR_SEC			0
+#define CCR_MIN			1
+#define CCR_HOUR		2
+#define CCR_MDAY		3
+#define CCR_MONTH		4
+#define CCR_YEAR		5
+#define CCR_WDAY		6
+#define CCR_Y2K			7
+
+#define X1205_REG_SR		0x3F	/* status register */
+#define X1205_REG_Y2K		0x37
+#define X1205_REG_DW		0x36
+#define X1205_REG_YR		0x35
+#define X1205_REG_MO		0x34
+#define X1205_REG_DT		0x33
+#define X1205_REG_HR		0x32
+#define X1205_REG_MN		0x31
+#define X1205_REG_SC		0x30
+#define X1205_REG_DTR		0x13
+#define X1205_REG_ATR		0x12
+#define X1205_REG_INT		0x11
+#define X1205_REG_0		0x10
+#define X1205_REG_Y2K1		0x0F
+#define X1205_REG_DWA1		0x0E
+#define X1205_REG_YRA1		0x0D
+#define X1205_REG_MOA1		0x0C
+#define X1205_REG_DTA1		0x0B
+#define X1205_REG_HRA1		0x0A
+#define X1205_REG_MNA1		0x09
+#define X1205_REG_SCA1		0x08
+#define X1205_REG_Y2K0		0x07
+#define X1205_REG_DWA0		0x06
+#define X1205_REG_YRA0		0x05
+#define X1205_REG_MOA0		0x04
+#define X1205_REG_DTA0		0x03
+#define X1205_REG_HRA0		0x02
+#define X1205_REG_MNA0		0x01
+#define X1205_REG_SCA0		0x00
+
+#define X1205_CCR_BASE		0x30	/* Base address of CCR */
+#define X1205_ALM0_BASE		0x00	/* Base address of ALARM0 */
+
+#define X1205_SR_RTCF		0x01	/* Clock failure */
+#define X1205_SR_WEL		0x02	/* Write Enable Latch */
+#define X1205_SR_RWEL		0x04	/* Register Write Enable */
+#define X1205_SR_AL0		0x20	/* Alarm 0 match */
+
+#define X1205_DTR_DTR0		0x01
+#define X1205_DTR_DTR1		0x02
+#define X1205_DTR_DTR2		0x04
+
+#define X1205_HR_MIL		0x80	/* Set in ccr.hour for 24 hr mode */
+
+#define X1205_INT_AL0E		0x20	/* Alarm 0 enable */
+
+static struct i2c_driver x1205_driver;
+
+/*
+ * In the routines that deal directly with the x1205 hardware, we use
+ * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
+ * Epoch is initialized as 2000. Time is set to UTC.
+ */
+static int x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm,
+				unsigned char reg_base)
+{
+	unsigned char dt_addr[2] = { 0, reg_base };
+	unsigned char buf[8];
+	int i;
+
+	struct i2c_msg msgs[] = {
+		{/* setup read ptr */
+			.addr = client->addr,
+			.len = 2,
+			.buf = dt_addr
+		},
+		{/* read date */
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = 8,
+			.buf = buf
+		},
+	};
+
+	/* read date registers */
+	if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
+		dev_err(&client->dev, "%s: read error\n", __func__);
+		return -EIO;
+	}
+
+	dev_dbg(&client->dev,
+		"%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
+		"mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
+		__func__,
+		buf[0], buf[1], buf[2], buf[3],
+		buf[4], buf[5], buf[6], buf[7]);
+
+	/* Mask out the enable bits if these are alarm registers */
+	if (reg_base < X1205_CCR_BASE)
+		for (i = 0; i <= 4; i++)
+			buf[i] &= 0x7F;
+
+	tm->tm_sec = bcd2bin(buf[CCR_SEC]);
+	tm->tm_min = bcd2bin(buf[CCR_MIN]);
+	tm->tm_hour = bcd2bin(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
+	tm->tm_mday = bcd2bin(buf[CCR_MDAY]);
+	tm->tm_mon = bcd2bin(buf[CCR_MONTH]) - 1; /* mon is 0-11 */
+	tm->tm_year = bcd2bin(buf[CCR_YEAR])
+			+ (bcd2bin(buf[CCR_Y2K]) * 100) - 1900;
+	tm->tm_wday = buf[CCR_WDAY];
+
+	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+		"mday=%d, mon=%d, year=%d, wday=%d\n",
+		__func__,
+		tm->tm_sec, tm->tm_min, tm->tm_hour,
+		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+	return 0;
+}
+
+static int x1205_get_status(struct i2c_client *client, unsigned char *sr)
+{
+	static unsigned char sr_addr[2] = { 0, X1205_REG_SR };
+
+	struct i2c_msg msgs[] = {
+		{     /* setup read ptr */
+			.addr = client->addr,
+			.len = 2,
+			.buf = sr_addr
+		},
+		{    /* read status */
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = 1,
+			.buf = sr
+		},
+	};
+
+	/* read status register */
+	if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
+		dev_err(&client->dev, "%s: read error\n", __func__);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm,
+			u8 reg_base, unsigned char alm_enable)
+{
+	int i, xfer;
+	unsigned char rdata[10] = { 0, reg_base };
+	unsigned char *buf = rdata + 2;
+
+	static const unsigned char wel[3] = { 0, X1205_REG_SR,
+						X1205_SR_WEL };
+
+	static const unsigned char rwel[3] = { 0, X1205_REG_SR,
+						X1205_SR_WEL | X1205_SR_RWEL };
+
+	static const unsigned char diswe[3] = { 0, X1205_REG_SR, 0 };
+
+	dev_dbg(&client->dev,
+		"%s: sec=%d min=%d hour=%d mday=%d mon=%d year=%d wday=%d\n",
+		__func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday,
+		tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+	buf[CCR_SEC] = bin2bcd(tm->tm_sec);
+	buf[CCR_MIN] = bin2bcd(tm->tm_min);
+
+	/* set hour and 24hr bit */
+	buf[CCR_HOUR] = bin2bcd(tm->tm_hour) | X1205_HR_MIL;
+
+	buf[CCR_MDAY] = bin2bcd(tm->tm_mday);
+
+	/* month, 1 - 12 */
+	buf[CCR_MONTH] = bin2bcd(tm->tm_mon + 1);
+
+	/* year, since the rtc epoch*/
+	buf[CCR_YEAR] = bin2bcd(tm->tm_year % 100);
+	buf[CCR_WDAY] = tm->tm_wday & 0x07;
+	buf[CCR_Y2K] = bin2bcd((tm->tm_year + 1900) / 100);
+
+	/* If writing alarm registers, set compare bits on registers 0-4 */
+	if (reg_base < X1205_CCR_BASE)
+		for (i = 0; i <= 4; i++)
+			buf[i] |= 0x80;
+
+	/* this sequence is required to unlock the chip */
+	xfer = i2c_master_send(client, wel, 3);
+	if (xfer != 3) {
+		dev_err(&client->dev, "%s: wel - %d\n", __func__, xfer);
+		return -EIO;
+	}
+
+	xfer = i2c_master_send(client, rwel, 3);
+	if (xfer != 3) {
+		dev_err(&client->dev, "%s: rwel - %d\n", __func__, xfer);
+		return -EIO;
+	}
+
+	xfer = i2c_master_send(client, rdata, sizeof(rdata));
+	if (xfer != sizeof(rdata)) {
+		dev_err(&client->dev,
+			"%s: result=%d addr=%02x, data=%02x\n",
+			__func__,
+			 xfer, rdata[1], rdata[2]);
+		return -EIO;
+	}
+
+	/* If we wrote to the nonvolatile region, wait 10msec for write cycle*/
+	if (reg_base < X1205_CCR_BASE) {
+		unsigned char al0e[3] = { 0, X1205_REG_INT, 0 };
+
+		msleep(10);
+
+		/* ...and set or clear the AL0E bit in the INT register */
+
+		/* Need to set RWEL again as the write has cleared it */
+		xfer = i2c_master_send(client, rwel, 3);
+		if (xfer != 3) {
+			dev_err(&client->dev,
+				"%s: aloe rwel - %d\n",
+				__func__,
+				xfer);
+			return -EIO;
+		}
+
+		if (alm_enable)
+			al0e[2] = X1205_INT_AL0E;
+
+		xfer = i2c_master_send(client, al0e, 3);
+		if (xfer != 3) {
+			dev_err(&client->dev,
+				"%s: al0e - %d\n",
+				__func__,
+				xfer);
+			return -EIO;
+		}
+
+		/* and wait 10msec again for this write to complete */
+		msleep(10);
+	}
+
+	/* disable further writes */
+	xfer = i2c_master_send(client, diswe, 3);
+	if (xfer != 3) {
+		dev_err(&client->dev, "%s: diswe - %d\n", __func__, xfer);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int x1205_fix_osc(struct i2c_client *client)
+{
+	int err;
+	struct rtc_time tm;
+
+	memset(&tm, 0, sizeof(tm));
+
+	err = x1205_set_datetime(client, &tm, X1205_CCR_BASE, 0);
+	if (err < 0)
+		dev_err(&client->dev, "unable to restart the oscillator\n");
+
+	return err;
+}
+
+static int x1205_get_dtrim(struct i2c_client *client, int *trim)
+{
+	unsigned char dtr;
+	static unsigned char dtr_addr[2] = { 0, X1205_REG_DTR };
+
+	struct i2c_msg msgs[] = {
+		{	/* setup read ptr */
+			.addr = client->addr,
+			.len = 2,
+			.buf = dtr_addr
+		},
+		{      /* read dtr */
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = 1,
+			.buf = &dtr
+		},
+	};
+
+	/* read dtr register */
+	if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
+		dev_err(&client->dev, "%s: read error\n", __func__);
+		return -EIO;
+	}
+
+	dev_dbg(&client->dev, "%s: raw dtr=%x\n", __func__, dtr);
+
+	*trim = 0;
+
+	if (dtr & X1205_DTR_DTR0)
+		*trim += 20;
+
+	if (dtr & X1205_DTR_DTR1)
+		*trim += 10;
+
+	if (dtr & X1205_DTR_DTR2)
+		*trim = -*trim;
+
+	return 0;
+}
+
+static int x1205_get_atrim(struct i2c_client *client, int *trim)
+{
+	s8 atr;
+	static unsigned char atr_addr[2] = { 0, X1205_REG_ATR };
+
+	struct i2c_msg msgs[] = {
+		{/* setup read ptr */
+			.addr = client->addr,
+			.len = 2,
+			.buf = atr_addr
+		},
+		{/* read atr */
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = 1,
+			.buf = &atr
+		},
+	};
+
+	/* read atr register */
+	if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
+		dev_err(&client->dev, "%s: read error\n", __func__);
+		return -EIO;
+	}
+
+	dev_dbg(&client->dev, "%s: raw atr=%x\n", __func__, atr);
+
+	/* atr is a two's complement value on 6 bits,
+	 * perform sign extension. The formula is
+	 * Catr = (atr * 0.25pF) + 11.00pF.
+	 */
+	atr = sign_extend32(atr, 5);
+
+	dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __func__, atr, atr);
+
+	*trim = (atr * 250) + 11000;
+
+	dev_dbg(&client->dev, "%s: real=%d\n", __func__, *trim);
+
+	return 0;
+}
+
+struct x1205_limit {
+	unsigned char reg, mask, min, max;
+};
+
+static int x1205_validate_client(struct i2c_client *client)
+{
+	int i, xfer;
+
+	/* Probe array. We will read the register at the specified
+	 * address and check if the given bits are zero.
+	 */
+	static const unsigned char probe_zero_pattern[] = {
+		/* register, mask */
+		X1205_REG_SR,	0x18,
+		X1205_REG_DTR,	0xF8,
+		X1205_REG_ATR,	0xC0,
+		X1205_REG_INT,	0x18,
+		X1205_REG_0,	0xFF,
+	};
+
+	static const struct x1205_limit probe_limits_pattern[] = {
+		/* register, mask, min, max */
+		{ X1205_REG_Y2K,	0xFF,	19,	20	},
+		{ X1205_REG_DW,		0xFF,	0,	6	},
+		{ X1205_REG_YR,		0xFF,	0,	99	},
+		{ X1205_REG_MO,		0xFF,	0,	12	},
+		{ X1205_REG_DT,		0xFF,	0,	31	},
+		{ X1205_REG_HR,		0x7F,	0,	23	},
+		{ X1205_REG_MN,		0xFF,	0,	59	},
+		{ X1205_REG_SC,		0xFF,	0,	59	},
+		{ X1205_REG_Y2K1,	0xFF,	19,	20	},
+		{ X1205_REG_Y2K0,	0xFF,	19,	20	},
+	};
+
+	/* check that registers have bits a 0 where expected */
+	for (i = 0; i < ARRAY_SIZE(probe_zero_pattern); i += 2) {
+		unsigned char buf;
+
+		unsigned char addr[2] = { 0, probe_zero_pattern[i] };
+
+		struct i2c_msg msgs[2] = {
+			{
+				.addr = client->addr,
+				.len = 2,
+				.buf = addr
+			},
+			{
+				.addr = client->addr,
+				.flags = I2C_M_RD,
+				.len = 1,
+				.buf = &buf
+			},
+		};
+
+		xfer = i2c_transfer(client->adapter, msgs, 2);
+		if (xfer != 2) {
+			dev_err(&client->dev,
+				"%s: could not read register %x\n",
+				__func__, probe_zero_pattern[i]);
+
+			return -EIO;
+		}
+
+		if ((buf & probe_zero_pattern[i+1]) != 0) {
+			dev_err(&client->dev,
+				"%s: register=%02x, zero pattern=%d, value=%x\n",
+				__func__, probe_zero_pattern[i], i, buf);
+
+			return -ENODEV;
+		}
+	}
+
+	/* check limits (only registers with bcd values) */
+	for (i = 0; i < ARRAY_SIZE(probe_limits_pattern); i++) {
+		unsigned char reg, value;
+
+		unsigned char addr[2] = { 0, probe_limits_pattern[i].reg };
+
+		struct i2c_msg msgs[2] = {
+			{
+				.addr = client->addr,
+				.len = 2,
+				.buf = addr
+			},
+			{
+				.addr = client->addr,
+				.flags = I2C_M_RD,
+				.len = 1,
+				.buf = &reg
+			},
+		};
+
+		xfer = i2c_transfer(client->adapter, msgs, 2);
+		if (xfer != 2) {
+			dev_err(&client->dev,
+				"%s: could not read register %x\n",
+				__func__, probe_limits_pattern[i].reg);
+
+			return -EIO;
+		}
+
+		value = bcd2bin(reg & probe_limits_pattern[i].mask);
+
+		if (value > probe_limits_pattern[i].max ||
+			value < probe_limits_pattern[i].min) {
+			dev_dbg(&client->dev,
+				"%s: register=%x, lim pattern=%d, value=%d\n",
+				__func__, probe_limits_pattern[i].reg,
+				i, value);
+
+			return -ENODEV;
+		}
+	}
+
+	return 0;
+}
+
+static int x1205_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	int err;
+	unsigned char intreg, status;
+	static unsigned char int_addr[2] = { 0, X1205_REG_INT };
+	struct i2c_client *client = to_i2c_client(dev);
+	struct i2c_msg msgs[] = {
+		{ /* setup read ptr */
+			.addr = client->addr,
+			.len = 2,
+			.buf = int_addr
+		},
+		{/* read INT register */
+
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = 1,
+			.buf = &intreg
+		},
+	};
+
+	/* read interrupt register and status register */
+	if (i2c_transfer(client->adapter, &msgs[0], 2) != 2) {
+		dev_err(&client->dev, "%s: read error\n", __func__);
+		return -EIO;
+	}
+	err = x1205_get_status(client, &status);
+	if (err == 0) {
+		alrm->pending = (status & X1205_SR_AL0) ? 1 : 0;
+		alrm->enabled = (intreg & X1205_INT_AL0E) ? 1 : 0;
+		err = x1205_get_datetime(client, &alrm->time, X1205_ALM0_BASE);
+	}
+	return err;
+}
+
+static int x1205_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	return x1205_set_datetime(to_i2c_client(dev),
+		&alrm->time, X1205_ALM0_BASE, alrm->enabled);
+}
+
+static int x1205_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	return x1205_get_datetime(to_i2c_client(dev),
+		tm, X1205_CCR_BASE);
+}
+
+static int x1205_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	return x1205_set_datetime(to_i2c_client(dev),
+		tm, X1205_CCR_BASE, 0);
+}
+
+static int x1205_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+	int err, dtrim, atrim;
+
+	err = x1205_get_dtrim(to_i2c_client(dev), &dtrim);
+	if (!err)
+		seq_printf(seq, "digital_trim\t: %d ppm\n", dtrim);
+
+	err = x1205_get_atrim(to_i2c_client(dev), &atrim);
+	if (!err)
+		seq_printf(seq, "analog_trim\t: %d.%02d pF\n",
+			atrim / 1000, atrim % 1000);
+	return 0;
+}
+
+static const struct rtc_class_ops x1205_rtc_ops = {
+	.proc		= x1205_rtc_proc,
+	.read_time	= x1205_rtc_read_time,
+	.set_time	= x1205_rtc_set_time,
+	.read_alarm	= x1205_rtc_read_alarm,
+	.set_alarm	= x1205_rtc_set_alarm,
+};
+
+static ssize_t x1205_sysfs_show_atrim(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	int err, atrim;
+
+	err = x1205_get_atrim(to_i2c_client(dev), &atrim);
+	if (err)
+		return err;
+
+	return sprintf(buf, "%d.%02d pF\n", atrim / 1000, atrim % 1000);
+}
+static DEVICE_ATTR(atrim, S_IRUGO, x1205_sysfs_show_atrim, NULL);
+
+static ssize_t x1205_sysfs_show_dtrim(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	int err, dtrim;
+
+	err = x1205_get_dtrim(to_i2c_client(dev), &dtrim);
+	if (err)
+		return err;
+
+	return sprintf(buf, "%d ppm\n", dtrim);
+}
+static DEVICE_ATTR(dtrim, S_IRUGO, x1205_sysfs_show_dtrim, NULL);
+
+static int x1205_sysfs_register(struct device *dev)
+{
+	int err;
+
+	err = device_create_file(dev, &dev_attr_atrim);
+	if (err)
+		return err;
+
+	err = device_create_file(dev, &dev_attr_dtrim);
+	if (err)
+		device_remove_file(dev, &dev_attr_atrim);
+
+	return err;
+}
+
+static void x1205_sysfs_unregister(struct device *dev)
+{
+	device_remove_file(dev, &dev_attr_atrim);
+	device_remove_file(dev, &dev_attr_dtrim);
+}
+
+
+static int x1205_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	int err = 0;
+	unsigned char sr;
+	struct rtc_device *rtc;
+
+	dev_dbg(&client->dev, "%s\n", __func__);
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -ENODEV;
+
+	if (x1205_validate_client(client) < 0)
+		return -ENODEV;
+
+	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
+
+	rtc = devm_rtc_device_register(&client->dev, x1205_driver.driver.name,
+					&x1205_rtc_ops, THIS_MODULE);
+
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	i2c_set_clientdata(client, rtc);
+
+	/* Check for power failures and eventually enable the osc */
+	err = x1205_get_status(client, &sr);
+	if (!err) {
+		if (sr & X1205_SR_RTCF) {
+			dev_err(&client->dev,
+				"power failure detected, "
+				"please set the clock\n");
+			udelay(50);
+			x1205_fix_osc(client);
+		}
+	} else {
+		dev_err(&client->dev, "couldn't read status\n");
+	}
+
+	err = x1205_sysfs_register(&client->dev);
+	if (err)
+		dev_err(&client->dev, "Unable to create sysfs entries\n");
+
+	return 0;
+}
+
+static int x1205_remove(struct i2c_client *client)
+{
+	x1205_sysfs_unregister(&client->dev);
+	return 0;
+}
+
+static const struct i2c_device_id x1205_id[] = {
+	{ "x1205", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, x1205_id);
+
+static struct i2c_driver x1205_driver = {
+	.driver		= {
+		.name	= "rtc-x1205",
+	},
+	.probe		= x1205_probe,
+	.remove		= x1205_remove,
+	.id_table	= x1205_id,
+};
+
+module_i2c_driver(x1205_driver);
+
+MODULE_AUTHOR(
+	"Karen Spearel <kas111 at gmail dot com>, "
+	"Alessandro Zummo <a.zummo@towertech.it>");
+MODULE_DESCRIPTION("Xicor/Intersil X1205 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);