summaryrefslogtreecommitdiff
path: root/drivers/rtc/rtc-isl1208.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/rtc/rtc-isl1208.c')
-rw-r--r--drivers/rtc/rtc-isl1208.c591
1 files changed, 591 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-isl1208.c b/drivers/rtc/rtc-isl1208.c
new file mode 100644
index 00000000000..f324d0a635d
--- /dev/null
+++ b/drivers/rtc/rtc-isl1208.c
@@ -0,0 +1,591 @@
+/*
+ * Intersil ISL1208 rtc class driver
+ *
+ * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+
+#define DRV_NAME "isl1208"
+#define DRV_VERSION "0.2"
+
+/* Register map */
+/* rtc section */
+#define ISL1208_REG_SC 0x00
+#define ISL1208_REG_MN 0x01
+#define ISL1208_REG_HR 0x02
+#define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */
+#define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
+#define ISL1208_REG_DT 0x03
+#define ISL1208_REG_MO 0x04
+#define ISL1208_REG_YR 0x05
+#define ISL1208_REG_DW 0x06
+#define ISL1208_RTC_SECTION_LEN 7
+
+/* control/status section */
+#define ISL1208_REG_SR 0x07
+#define ISL1208_REG_SR_ARST (1<<7) /* auto reset */
+#define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */
+#define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */
+#define ISL1208_REG_SR_ALM (1<<2) /* alarm */
+#define ISL1208_REG_SR_BAT (1<<1) /* battery */
+#define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */
+#define ISL1208_REG_INT 0x08
+#define ISL1208_REG_09 0x09 /* reserved */
+#define ISL1208_REG_ATR 0x0a
+#define ISL1208_REG_DTR 0x0b
+
+/* alarm section */
+#define ISL1208_REG_SCA 0x0c
+#define ISL1208_REG_MNA 0x0d
+#define ISL1208_REG_HRA 0x0e
+#define ISL1208_REG_DTA 0x0f
+#define ISL1208_REG_MOA 0x10
+#define ISL1208_REG_DWA 0x11
+#define ISL1208_ALARM_SECTION_LEN 6
+
+/* user section */
+#define ISL1208_REG_USR1 0x12
+#define ISL1208_REG_USR2 0x13
+#define ISL1208_USR_SECTION_LEN 2
+
+/* i2c configuration */
+#define ISL1208_I2C_ADDR 0xde
+
+static unsigned short normal_i2c[] = {
+ ISL1208_I2C_ADDR>>1, I2C_CLIENT_END
+};
+I2C_CLIENT_INSMOD; /* defines addr_data */
+
+static int isl1208_attach_adapter(struct i2c_adapter *adapter);
+static int isl1208_detach_client(struct i2c_client *client);
+
+static struct i2c_driver isl1208_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ },
+ .id = I2C_DRIVERID_ISL1208,
+ .attach_adapter = &isl1208_attach_adapter,
+ .detach_client = &isl1208_detach_client,
+};
+
+/* block read */
+static int
+isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
+ unsigned len)
+{
+ u8 reg_addr[1] = { reg };
+ struct i2c_msg msgs[2] = {
+ { client->addr, client->flags, sizeof(reg_addr), reg_addr },
+ { client->addr, client->flags | I2C_M_RD, len, buf }
+ };
+ int ret;
+
+ BUG_ON(len == 0);
+ BUG_ON(reg > ISL1208_REG_USR2);
+ BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
+
+ ret = i2c_transfer(client->adapter, msgs, 2);
+ if (ret > 0)
+ ret = 0;
+ return ret;
+}
+
+/* block write */
+static int
+isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
+ unsigned len)
+{
+ u8 i2c_buf[ISL1208_REG_USR2 + 2];
+ struct i2c_msg msgs[1] = {
+ { client->addr, client->flags, len + 1, i2c_buf }
+ };
+ int ret;
+
+ BUG_ON(len == 0);
+ BUG_ON(reg > ISL1208_REG_USR2);
+ BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
+
+ i2c_buf[0] = reg;
+ memcpy(&i2c_buf[1], &buf[0], len);
+
+ ret = i2c_transfer(client->adapter, msgs, 1);
+ if (ret > 0)
+ ret = 0;
+ return ret;
+}
+
+/* simple check to see wether we have a isl1208 */
+static int isl1208_i2c_validate_client(struct i2c_client *client)
+{
+ u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
+ u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
+ 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
+ };
+ int i;
+ int ret;
+
+ ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
+ if (ret < 0)
+ return ret;
+
+ for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
+ if (regs[i] & zero_mask[i]) /* check if bits are cleared */
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int isl1208_i2c_get_sr(struct i2c_client *client)
+{
+ return i2c_smbus_read_byte_data(client, ISL1208_REG_SR) == -1 ? -EIO:0;
+}
+
+static int isl1208_i2c_get_atr(struct i2c_client *client)
+{
+ int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
+
+ if (atr < 0)
+ return -EIO;
+
+ /* The 6bit value in the ATR register controls the load
+ * capacitance C_load * in steps of 0.25pF
+ *
+ * bit (1<<5) of the ATR register is inverted
+ *
+ * C_load(ATR=0x20) = 4.50pF
+ * C_load(ATR=0x00) = 12.50pF
+ * C_load(ATR=0x1f) = 20.25pF
+ *
+ */
+
+ atr &= 0x3f; /* mask out lsb */
+ atr ^= 1<<5; /* invert 6th bit */
+ atr += 2*9; /* add offset of 4.5pF; unit[atr] = 0.25pF */
+
+ return atr;
+}
+
+static int isl1208_i2c_get_dtr(struct i2c_client *client)
+{
+ int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
+
+ if (dtr < 0)
+ return -EIO;
+
+ /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
+ dtr = ((dtr & 0x3) * 20) * (dtr & (1<<2) ? -1 : 1);
+
+ return dtr;
+}
+
+static int isl1208_i2c_get_usr(struct i2c_client *client)
+{
+ u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
+ int ret;
+
+ ret = isl1208_i2c_read_regs (client, ISL1208_REG_USR1, buf,
+ ISL1208_USR_SECTION_LEN);
+ if (ret < 0)
+ return ret;
+
+ return (buf[1] << 8) | buf[0];
+}
+
+static int isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
+{
+ u8 buf[ISL1208_USR_SECTION_LEN];
+
+ buf[0] = usr & 0xff;
+ buf[1] = (usr >> 8) & 0xff;
+
+ return isl1208_i2c_set_regs (client, ISL1208_REG_USR1, buf,
+ ISL1208_USR_SECTION_LEN);
+}
+
+static int isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+ struct i2c_client *const client = to_i2c_client(dev);
+ int sr, dtr, atr, usr;
+
+ sr = isl1208_i2c_get_sr(client);
+ if (sr < 0) {
+ dev_err(&client->dev, "%s: reading SR failed\n", __func__);
+ return sr;
+ }
+
+ seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
+ (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
+ (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
+ (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
+ (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
+ (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
+ (sr & ISL1208_REG_SR_ARST) ? " ARST" : "",
+ sr);
+
+ seq_printf(seq, "batt_status\t: %s\n",
+ (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
+
+ dtr = isl1208_i2c_get_dtr(client);
+ if (dtr >= 0 -1)
+ seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);
+
+ atr = isl1208_i2c_get_atr(client);
+ if (atr >= 0)
+ seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
+ atr>>2, (atr&0x3)*25);
+
+ usr = isl1208_i2c_get_usr(client);
+ if (usr >= 0)
+ seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
+
+ return 0;
+}
+
+
+static int isl1208_i2c_read_time(struct i2c_client *client,
+ struct rtc_time *tm)
+{
+ int sr;
+ u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
+
+ sr = isl1208_i2c_get_sr(client);
+ if (sr < 0) {
+ dev_err(&client->dev, "%s: reading SR failed\n", __func__);
+ return -EIO;
+ }
+
+ sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
+ if (sr < 0) {
+ dev_err(&client->dev, "%s: reading RTC section failed\n",
+ __func__);
+ return sr;
+ }
+
+ tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SC]);
+ tm->tm_min = BCD2BIN(regs[ISL1208_REG_MN]);
+ { /* HR field has a more complex interpretation */
+ const u8 _hr = regs[ISL1208_REG_HR];
+ if (_hr & ISL1208_REG_HR_MIL) /* 24h format */
+ tm->tm_hour = BCD2BIN(_hr & 0x3f);
+ else { // 12h format
+ tm->tm_hour = BCD2BIN(_hr & 0x1f);
+ if (_hr & ISL1208_REG_HR_PM) /* PM flag set */
+ tm->tm_hour += 12;
+ }
+ }
+
+ tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DT]);
+ tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
+ tm->tm_year = BCD2BIN(regs[ISL1208_REG_YR]) + 100;
+ tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DW]);
+
+ return 0;
+}
+
+static int isl1208_i2c_read_alarm(struct i2c_client *client,
+ struct rtc_wkalrm *alarm)
+{
+ struct rtc_time *const tm = &alarm->time;
+ u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
+ int sr;
+
+ sr = isl1208_i2c_get_sr(client);
+ if (sr < 0) {
+ dev_err(&client->dev, "%s: reading SR failed\n", __func__);
+ return sr;
+ }
+
+ sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
+ ISL1208_ALARM_SECTION_LEN);
+ if (sr < 0) {
+ dev_err(&client->dev, "%s: reading alarm section failed\n",
+ __func__);
+ return sr;
+ }
+
+ /* MSB of each alarm register is an enable bit */
+ tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SCA-ISL1208_REG_SCA] & 0x7f);
+ tm->tm_min = BCD2BIN(regs[ISL1208_REG_MNA-ISL1208_REG_SCA] & 0x7f);
+ tm->tm_hour = BCD2BIN(regs[ISL1208_REG_HRA-ISL1208_REG_SCA] & 0x3f);
+ tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DTA-ISL1208_REG_SCA] & 0x3f);
+ tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MOA-ISL1208_REG_SCA] & 0x1f)-1;
+ tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DWA-ISL1208_REG_SCA] & 0x03);
+
+ return 0;
+}
+
+static int isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ return isl1208_i2c_read_time(to_i2c_client(dev), tm);
+}
+
+static int isl1208_i2c_set_time(struct i2c_client *client,
+ struct rtc_time const *tm)
+{
+ int sr;
+ u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
+
+ regs[ISL1208_REG_SC] = BIN2BCD(tm->tm_sec);
+ regs[ISL1208_REG_MN] = BIN2BCD(tm->tm_min);
+ regs[ISL1208_REG_HR] = BIN2BCD(tm->tm_hour) | ISL1208_REG_HR_MIL;
+
+ regs[ISL1208_REG_DT] = BIN2BCD(tm->tm_mday);
+ regs[ISL1208_REG_MO] = BIN2BCD(tm->tm_mon + 1);
+ regs[ISL1208_REG_YR] = BIN2BCD(tm->tm_year - 100);
+
+ regs[ISL1208_REG_DW] = BIN2BCD(tm->tm_wday & 7);
+
+ sr = isl1208_i2c_get_sr(client);
+ if (sr < 0) {
+ dev_err(&client->dev, "%s: reading SR failed\n", __func__);
+ return sr;
+ }
+
+ /* set WRTC */
+ sr = i2c_smbus_write_byte_data (client, ISL1208_REG_SR,
+ sr | ISL1208_REG_SR_WRTC);
+ if (sr < 0) {
+ dev_err(&client->dev, "%s: writing SR failed\n", __func__);
+ return sr;
+ }
+
+ /* write RTC registers */
+ sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
+ if (sr < 0) {
+ dev_err(&client->dev, "%s: writing RTC section failed\n",
+ __func__);
+ return sr;
+ }
+
+ /* clear WRTC again */
+ sr = i2c_smbus_write_byte_data (client, ISL1208_REG_SR,
+ sr & ~ISL1208_REG_SR_WRTC);
+ if (sr < 0) {
+ dev_err(&client->dev, "%s: writing SR failed\n", __func__);
+ return sr;
+ }
+
+ return 0;
+}
+
+
+static int isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ return isl1208_i2c_set_time(to_i2c_client(dev), tm);
+}
+
+static int isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
+}
+
+static struct rtc_class_ops isl1208_rtc_ops = {
+ .proc = isl1208_rtc_proc,
+ .read_time = isl1208_rtc_read_time,
+ .set_time = isl1208_rtc_set_time,
+ .read_alarm = isl1208_rtc_read_alarm,
+ //.set_alarm = isl1208_rtc_set_alarm,
+};
+
+/* sysfs interface */
+
+static ssize_t isl1208_sysfs_show_atrim(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int atr;
+
+ atr = isl1208_i2c_get_atr(to_i2c_client(dev));
+ if (atr < 0)
+ return atr;
+
+ return sprintf(buf, "%d.%.2d pF\n", atr>>2, (atr&0x3)*25);
+}
+static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
+
+static ssize_t isl1208_sysfs_show_dtrim(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int dtr;
+
+ dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
+ if (dtr < 0)
+ return dtr;
+
+ return sprintf(buf, "%d ppm\n", dtr);
+}
+static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
+
+static ssize_t isl1208_sysfs_show_usr(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int usr;
+
+ usr = isl1208_i2c_get_usr(to_i2c_client(dev));
+ if (usr < 0)
+ return usr;
+
+ return sprintf(buf, "0x%.4x\n", usr);
+}
+
+static ssize_t isl1208_sysfs_store_usr(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int usr = -1;
+
+ if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
+ if (sscanf(buf, "%x", &usr) != 1)
+ return -EINVAL;
+ } else {
+ if (sscanf(buf, "%d", &usr) != 1)
+ return -EINVAL;
+ }
+
+ if (usr < 0 || usr > 0xffff)
+ return -EINVAL;
+
+ return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
+}
+static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
+ isl1208_sysfs_store_usr);
+
+static int
+isl1208_probe(struct i2c_adapter *adapter, int addr, int kind)
+{
+ int rc = 0;
+ struct i2c_client *new_client = NULL;
+ struct rtc_device *rtc = NULL;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
+ rc = -ENODEV;
+ goto failout;
+ }
+
+ new_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
+ if (new_client == NULL) {
+ rc = -ENOMEM;
+ goto failout;
+ }
+
+ new_client->addr = addr;
+ new_client->adapter = adapter;
+ new_client->driver = &isl1208_driver;
+ new_client->flags = 0;
+ strcpy(new_client->name, DRV_NAME);
+
+ if (kind < 0) {
+ rc = isl1208_i2c_validate_client(new_client);
+ if (rc < 0)
+ goto failout;
+ }
+
+ rc = i2c_attach_client(new_client);
+ if (rc < 0)
+ goto failout;
+
+ dev_info(&new_client->dev,
+ "chip found, driver version " DRV_VERSION "\n");
+
+ rtc = rtc_device_register(isl1208_driver.driver.name,
+ &new_client->dev,
+ &isl1208_rtc_ops, THIS_MODULE);
+
+ if (IS_ERR(rtc)) {
+ rc = PTR_ERR(rtc);
+ goto failout_detach;
+ }
+
+ i2c_set_clientdata(new_client, rtc);
+
+ rc = isl1208_i2c_get_sr(new_client);
+ if (rc < 0) {
+ dev_err(&new_client->dev, "reading status failed\n");
+ goto failout_unregister;
+ }
+
+ if (rc & ISL1208_REG_SR_RTCF)
+ dev_warn(&new_client->dev, "rtc power failure detected, "
+ "please set clock.\n");
+
+ rc = device_create_file(&new_client->dev, &dev_attr_atrim);
+ if (rc < 0)
+ goto failout_unregister;
+ rc = device_create_file(&new_client->dev, &dev_attr_dtrim);
+ if (rc < 0)
+ goto failout_atrim;
+ rc = device_create_file(&new_client->dev, &dev_attr_usr);
+ if (rc < 0)
+ goto failout_dtrim;
+
+ return 0;
+
+ failout_dtrim:
+ device_remove_file(&new_client->dev, &dev_attr_dtrim);
+ failout_atrim:
+ device_remove_file(&new_client->dev, &dev_attr_atrim);
+ failout_unregister:
+ rtc_device_unregister(rtc);
+ failout_detach:
+ i2c_detach_client(new_client);
+ failout:
+ kfree(new_client);
+ return rc;
+}
+
+static int
+isl1208_attach_adapter (struct i2c_adapter *adapter)
+{
+ return i2c_probe(adapter, &addr_data, isl1208_probe);
+}
+
+static int
+isl1208_detach_client(struct i2c_client *client)
+{
+ int rc;
+ struct rtc_device *const rtc = i2c_get_clientdata(client);
+
+ if (rtc)
+ rtc_device_unregister(rtc); /* do we need to kfree? */
+
+ rc = i2c_detach_client(client);
+ if (rc)
+ return rc;
+
+ kfree(client);
+
+ return 0;
+}
+
+/* module management */
+
+static int __init isl1208_init(void)
+{
+ return i2c_add_driver(&isl1208_driver);
+}
+
+static void __exit isl1208_exit(void)
+{
+ i2c_del_driver(&isl1208_driver);
+}
+
+MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
+MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+
+module_init(isl1208_init);
+module_exit(isl1208_exit);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-18 16:31:04 +0000