- 这段时间编了个RTC芯片ISL12020M的驱动程序，程序大部分是从ISL1208上移植过来的。寄存器地址进行了重新设置。现在已经编译通过了，还是有点成就感。嘿嘿。代码如下：
/* * Intersil ISL12020M rtc class driver * * * * 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 "isl12020m" #define DRV_VERSION "0.2" /* Register map */ /* rtc section */ #define ISL12020M_REG_SC 0x00 #define ISL12020M_REG_MN 0x01 #define ISL12020M_REG_HR 0x02 #define ISL12020M_REG_HR_MIL (1<<7) /* 24h/12h mode */ #define ISL12020M_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */ #define ISL12020M_REG_DT 0x03 #define ISL12020M_REG_MO 0x04 #define ISL12020M_REG_YR 0x05 #define ISL12020M_REG_DW 0x06 #define ISL12020M_RTC_SECTION_LEN 7 /* control/status section */ #define ISL12020M_REG_SR 0x07 /* status reg */ #define ISL12020M_REG_SR_DSTADJ (1<<5) /* daylight saving time change */ #define ISL12020M_REG_SR_ALM (1<<4) /* alarm bit ,can only set 0 */ #define ISL12020M_REG_SR_LBAT85 (1<<2) /* low battery indicator 85% */ #define ISL12020M_REG_SR_LBAT75 (1<<1) /* low battery indicator 75% */ #define ISL12020M_REG_SR_RTCF (1<<0) /* real time clock fail */ #define ISL12020M_REG_INT 0x08 /* interrupt control reg */ #define ISL12020M_REG_INT_ARST (1<<7) /* automatic reset */ #define ISL12020M_REG_INT_WRTC (1<<6) /* write rtc enable */ #define ISL12020M_REG_INT_IM (1<<5) /* interrupt/alarm mode */ #define ISL12020M_REG_INT_FOBATB (1<<4) /* frequency output and interrupt */ #define ISL12020M_REG_PWR_VDD 0x09 /* power supply control reg */ #define ISL12020M_REG_PWR_VDD_CLRTS (1<<7) /* clear time stamp VDD to battery and time stamp battery to VDD regs */ #define ISL12020M_REG_PWR_VBAT 0x0A /* battery voltage trip voltage reg */ #define ISL12020M_REG_ITR0 0x0B /* initial AT and DT setting reg */ #define ISL12020M_REG_ALPHA 0x0C /* ALPHA reg ,temperature coefficient */ #define ISL12020M_REG_BETA 0x0D /* BETA reg, */ #define ISL12020M_REG_BETA_TSE (1<<7) /* temperature sensor enable */ #define ISL12020M_REG_FATR 0x0E /* final analog trimming reg */ #define ISL12020M_REG_FDTR 0x0F /* final digital trimming reg */ /* alarm section */ #define ISL12020M_REG_SCA0 0x10 /* second */ #define ISL12020M_REG_MNA0 0x11 /* minute */ #define ISL12020M_REG_HRA0 0x12 /* hour */ #define ISL12020M_REG_DTA0 0x13 /* date */ #define ISL12020M_REG_MOA0 0x14 /* month */ #define ISL12020M_REG_DWA0 0x15 /* day of week */ #define ISL12020M_ALARM_SECTION_LEN 6 /* TSV2B section, time stamp VDD to battery*/ #define ISL12020M_REG_VSC 0x16 #define ISL12020M_REG_VMN 0x17 #define ISL12020M_REG_VHR 0x18 #define ISL12020M_REG_VDT 0x19 #define ISL12020M_REG_VMO 0x1A /* TSB2V, time stamp battery to VDD */ #define ISL12020M_REG_BSC 0x1B #define ISL12020M_REG_BMN 0x1C #define ISL12020M_REG_BHR 0x1D #define ISL12020M_REG_BDT 0x1E #define ISL12020M_REG_BMO 0x1F /* DSTCR, DST control regs */ /* DST begginning time, set forward */ #define ISL12020M_REG_DSTMOFD 0x20 #define ISL12020M_REG_DSTMOFD_DSTE (1<<7) /* dst enable bit */ #define ISL12020M_REG_DSTDWFD 0x21 #define ISL12020M_REG_DSTDWFD_DSTDWFDE (1<<6 ) /* set the priority of the day/week over the date */ #define ISL12020M_REG_DSTDTFD 0x22 #define ISL12020M_REG_DSTHRFD 0x23 /* DST ending time, set backward or reverse */ #define ISL12020M_REG_DSTMORV 0x24 #define ISL12020M_REG_DSTDWRV 0x25 #define ISL12020M_REG_DSTDWRV_DSTDWRVE (1<<6) /* set the priority of the day/week over the date */ #define ISL12020M_REG_DSTDTRV 0x26 #define ISL12020M_REG_DSTHRRV 0x27 /* temperature regs*/ #define ISL12020M_REG_TK0L 0x28 /*LSB 8 bit*/ #define ISL12020M_REG_TK0M 0x29 /* MSB 2 bit */ /* NPPM */ #define ISL12020M_REG_NPPML 0x2A #define ISL12020M_REG_NPPMH 0x2B /* XT0 regs */ #define ISL12020M_REG_XT0 0x2C /* ALPHA hot reg */ #define ISL12020M_REG_ALPHAH 0x2D /* GPM section ,general purpose user sram */ #define ISL12020M_REG_GPM1 0x2E #define ISL12020M_REG_GPM2 0x2F #define ISL12020M_GPM_SECTION_LEN 2 /* i2c configuration */ #define ISL12020M_I2C_ADDR 0xde /* 1101 1110*/ static unsigned short normal_i2c[] = { ISL12020M_I2C_ADDR>>1, I2C_CLIENT_END }; I2C_CLIENT_INSMOD; /* defines addr_data */ static int isl12020m_attach_adapter(struct i2c_adapter *adapter); static int isl12020m_detach_client(struct i2c_client *client); static struct i2c_driver isl12020m_driver = { .driver = { .name = DRV_NAME, }, .id = I2C_DRIVERID_ISL12020M, .attach_adapter = &isl12020m_attach_adapter, .detach_client = &isl12020m_detach_client, }; /* block read */ static int isl12020m_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 > ISL12020M_REG_GPM2); BUG_ON(reg + len > ISL12020M_REG_GPM2 + 1); ret = i2c_transfer(client->adapter, msgs, 2); if (ret > 0) ret = 0; return ret; } /* block write */ static int isl12020m_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[], unsigned len) { u8 i2c_buf[ISL12020M_REG_GPM2 + 2]; struct i2c_msg msgs[1] = { { client->addr, client->flags, len + 1, i2c_buf } }; int ret; BUG_ON(len == 0); BUG_ON(reg > ISL12020M_REG_GPM2); BUG_ON(reg + len > ISL12020M_REG_GPM2 + 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 isl12020m */ static int isl12020m_i2c_validate_client(struct i2c_client *client) { u8 regs[ISL12020M_RTC_SECTION_LEN] = { 0, }; u8 zero_mask[ISL12020M_RTC_SECTION_LEN] = { 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8 //1000 = 8 }; int i; int ret; ret = isl12020m_i2c_read_regs(client, 0, regs, ISL12020M_RTC_SECTION_LEN); if (ret < 0) return ret; for (i = 0; i < ISL12020M_RTC_SECTION_LEN; ++i) { if (regs[i] & zero_mask[i]) /* check if bits are cleared */ return -ENODEV; } return 0; } static int isl12020m_i2c_get_sr(struct i2c_client *client) { return i2c_smbus_read_byte_data(client, ISL12020M_REG_SR) == -1 ? -EIO:0; } static int isl12020m_i2c_get_fatr(struct i2c_client *client) { int fatr = i2c_smbus_read_byte_data(client, ISL12020M_REG_FATR); if (fatr < 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 * */ fatr &= 0x3f; /* mask out lsb */ fatr ^= 1<<5; /* invert 6th bit */ fatr += 2*9; /* add offset of 4.5pF; unit[atr] = 0.25pF */ return fatr; } static int isl12020m_i2c_get_fdtr(struct i2c_client *client) { int fdtr = i2c_smbus_read_byte_data(client, ISL12020M_REG_FDTR); if (fdtr < 0) return -EIO; /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */ fdtr = ((fdtr & 0x3) * 20) * (fdtr & (1<<2) ? -1 : 1); return fdtr; } static int isl12020m_i2c_get_gpm(struct i2c_client *client) { u8 buf[ISL12020M_GPM_SECTION_LEN] = { 0, }; int ret; ret = isl12020m_i2c_read_regs (client, ISL12020M_REG_GPM1, buf, ISL12020M_GPM_SECTION_LEN); if (ret < 0) return ret; return (buf[1] << 8) | buf[0]; } static int isl12020m_i2c_set_gpm(struct i2c_client *client, u16 usr) { u8 buf[ISL12020M_GPM_SECTION_LEN]; buf[0] = usr & 0xff; buf[1] = (usr >> 8) & 0xff; return isl12020m_i2c_set_regs (client, ISL12020M_REG_GPM1, buf, ISL12020M_GPM_SECTION_LEN); } static int isl12020m_rtc_proc(struct device *dev, struct seq_file *seq) { struct i2c_client *const client = to_i2c_client(dev); int sr, fdtr, fatr, usr; sr = isl12020m_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 (0x%.2x)\n", //%s%s%s%s get out (sr & ISL12020M_REG_SR_RTCF) ? " RTCF" : "", // (sr & ISL12020M_REG_SR_BAT) ? " BAT" : "", (sr & ISL12020M_REG_SR_ALM) ? " ALM" : "", // (sr & ISL12020M_REG_SR_WRTC) ? " WRTC" : "", // (sr & ISL12020M_REG_SR_XTOSCB) ? " XTOSCB" : "", // (sr & ISL12020M_REG_SR_ARST) ? " ARST" : "", sr); seq_printf(seq, "batt_status\t: %s\n", (sr & ISL12020M_REG_SR_RTCF) ? "bad" : "okay"); fdtr = isl12020m_i2c_get_fdtr(client); if (fdtr >= 0 -1) seq_printf(seq, "digital_trim\t: %d ppm\n", fdtr); fatr = isl12020m_i2c_get_fatr(client); if (fatr >= 0) seq_printf(seq, "analog_trim\t: %d.%.2d pF\n", fatr>>2, (fatr&0x3)*25); usr = isl12020m_i2c_get_gpm(client); if (usr >= 0) seq_printf(seq, "user_data\t: 0x%.4x\n", usr); return 0; } static int isl12020m_i2c_read_time(struct i2c_client *client, struct rtc_time *tm) { int sr; u8 regs[ISL12020M_RTC_SECTION_LEN] = { 0, }; sr = isl12020m_i2c_get_sr(client); if (sr < 0) { dev_err(&client->dev, "%s: reading SR failed\n", __func__); return -EIO; } sr = isl12020m_i2c_read_regs(client, 0, regs, ISL12020M_RTC_SECTION_LEN); if (sr < 0) { dev_err(&client->dev, "%s: reading RTC section failed\n", __func__); return sr; } tm->tm_sec = BCD2BIN(regs[ISL12020M_REG_SC]); tm->tm_min = BCD2BIN(regs[ISL12020M_REG_MN]); { /* HR field has a more complex interpretation */ const u8 _hr = regs[ISL12020M_REG_HR]; if (_hr & ISL12020M_REG_HR_MIL) /* 24h format */ tm->tm_hour = BCD2BIN(_hr & 0x3f); else { // 12h format tm->tm_hour = BCD2BIN(_hr & 0x1f); if (_hr & ISL12020M_REG_HR_PM) /* PM flag set */ tm->tm_hour += 12; } } tm->tm_mday = BCD2BIN(regs[ISL12020M_REG_DT]); tm->tm_mon = BCD2BIN(regs[ISL12020M_REG_MO]) - 1; /* rtc starts at 1 */ tm->tm_year = BCD2BIN(regs[ISL12020M_REG_YR]) + 100; tm->tm_wday = BCD2BIN(regs[ISL12020M_REG_DW]); return 0; } static int isl12020m_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm) { struct rtc_time *const tm = &alarm->time; u8 regs[ISL12020M_ALARM_SECTION_LEN] = { 0, }; int sr; sr = isl12020m_i2c_get_sr(client); if (sr < 0) { dev_err(&client->dev, "%s: reading SR failed\n", __func__); return sr; } sr = isl12020m_i2c_read_regs(client, ISL12020M_REG_SCA0, regs, ISL12020M_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[ISL12020M_REG_SCA0-ISL12020M_REG_SCA0] & 0x7f); tm->tm_min = BCD2BIN(regs[ISL12020M_REG_MNA0-ISL12020M_REG_SCA0] & 0x7f); tm->tm_hour = BCD2BIN(regs[ISL12020M_REG_HRA0-ISL12020M_REG_SCA0] & 0x3f); tm->tm_mday = BCD2BIN(regs[ISL12020M_REG_DTA0-ISL12020M_REG_SCA0] & 0x3f); tm->tm_mon = BCD2BIN(regs[ISL12020M_REG_MOA0-ISL12020M_REG_SCA0] & 0x1f)-1; tm->tm_wday = BCD2BIN(regs[ISL12020M_REG_DWA0-ISL12020M_REG_SCA0] & 0x03); return 0; } static int isl12020m_rtc_read_time(struct device *dev, struct rtc_time *tm) { return isl12020m_i2c_read_time(to_i2c_client(dev), tm); } static int isl12020m_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm) { int sr; u8 regs[ISL12020M_RTC_SECTION_LEN] = { 0, }; regs[ISL12020M_REG_SC] = BIN2BCD(tm->tm_sec); regs[ISL12020M_REG_MN] = BIN2BCD(tm->tm_min); regs[ISL12020M_REG_HR] = BIN2BCD(tm->tm_hour) | ISL12020M_REG_HR_MIL; regs[ISL12020M_REG_DT] = BIN2BCD(tm->tm_mday); regs[ISL12020M_REG_MO] = BIN2BCD(tm->tm_mon + 1); regs[ISL12020M_REG_YR] = BIN2BCD(tm->tm_year - 100); regs[ISL12020M_REG_DW] = BIN2BCD(tm->tm_wday & 7); sr = isl12020m_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, ISL12020M_REG_SR, sr | ISL12020M_REG_INT_WRTC); if (sr < 0) { dev_err(&client->dev, "%s: writing SR failed\n", __func__); return sr; } /* write RTC registers */ sr = isl12020m_i2c_set_regs(client, 0, regs, ISL12020M_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, ISL12020M_REG_SR, sr & ~ISL12020M_REG_INT_WRTC); if (sr < 0) { dev_err(&client->dev, "%s: writing SR failed\n", __func__); return sr; } return 0; } static int isl12020m_rtc_set_time(struct device *dev, struct rtc_time *tm) { return isl12020m_i2c_set_time(to_i2c_client(dev), tm); } static int isl12020m_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) { return isl12020m_i2c_read_alarm(to_i2c_client(dev), alarm); } static const struct rtc_class_ops isl12020m_rtc_ops = { .proc = isl12020m_rtc_proc, .read_time = isl12020m_rtc_read_time, .set_time = isl12020m_rtc_set_time, .read_alarm = isl12020m_rtc_read_alarm, //.set_alarm = isl1208_rtc_set_alarm, }; /* sysfs interface */ static ssize_t isl12020m_sysfs_show_atrim(struct device *dev, struct device_attribute *attr, char *buf) { int fatr; fatr = isl12020m_i2c_get_fatr(to_i2c_client(dev)); if (fatr < 0) return fatr; return sprintf(buf, "%d.%.2d pF\n", fatr>>2, (fatr&0x3)*25); } static DEVICE_ATTR(atrim, S_IRUGO, isl12020m_sysfs_show_atrim, NULL); static ssize_t isl12020m_sysfs_show_dtrim(struct device *dev, struct device_attribute *attr, char *buf) { int fdtr; fdtr = isl12020m_i2c_get_fdtr(to_i2c_client(dev)); if (fdtr < 0) return fdtr; return sprintf(buf, "%d ppm\n", fdtr); } static DEVICE_ATTR(dtrim, S_IRUGO, isl12020m_sysfs_show_dtrim, NULL); static ssize_t isl12020m_sysfs_show_usr(struct device *dev, struct device_attribute *attr, char *buf) { int usr; usr = isl12020m_i2c_get_gpm(to_i2c_client(dev)); if (usr < 0) return usr; return sprintf(buf, "0x%.4x\n", usr); } static ssize_t isl12020m_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 isl12020m_i2c_set_gpm(to_i2c_client(dev), usr) ? -EIO : count; } static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl12020m_sysfs_show_usr, isl12020m_sysfs_store_usr); static int isl12020m_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 = &isl12020m_driver; new_client->flags = 0; strcpy(new_client->name, DRV_NAME); if (kind < 0) { rc = isl12020m_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(isl12020m_driver.driver.name, &new_client->dev, &isl12020m_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) { rc = PTR_ERR(rtc); goto failout_detach; } i2c_set_clientdata(new_client, rtc); rc = isl12020m_i2c_get_sr(new_client); if (rc < 0) { dev_err(&new_client->dev, "reading status failed\n"); goto failout_unregister; } if (rc & ISL12020M_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 isl12020m_attach_adapter (struct i2c_adapter *adapter) { return i2c_probe(adapter, &addr_data, isl12020m_probe); } static int isl12020m_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 isl12020m_init(void) { return i2c_add_driver(&isl12020m_driver); } static void __exit isl12020m_exit(void) { i2c_del_driver(&isl12020m_driver); } MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>"); MODULE_DESCRIPTION("Intersil ISL12020M RTC driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_VERSION); module_init(isl12020m_init); module_exit(isl12020m_exit);
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