575 lines
13 KiB
C
575 lines
13 KiB
C
/*
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* Intersil ISL1208 rtc class driver
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*
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* Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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*/
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/bcd.h>
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#include <linux/rtc.h>
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#define DRV_VERSION "0.3"
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/* Register map */
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/* rtc section */
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#define ISL1208_REG_SC 0x00
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#define ISL1208_REG_MN 0x01
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#define ISL1208_REG_HR 0x02
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#define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */
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#define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
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#define ISL1208_REG_DT 0x03
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#define ISL1208_REG_MO 0x04
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#define ISL1208_REG_YR 0x05
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#define ISL1208_REG_DW 0x06
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#define ISL1208_RTC_SECTION_LEN 7
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/* control/status section */
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#define ISL1208_REG_SR 0x07
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#define ISL1208_REG_SR_ARST (1<<7) /* auto reset */
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#define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */
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#define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */
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#define ISL1208_REG_SR_ALM (1<<2) /* alarm */
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#define ISL1208_REG_SR_BAT (1<<1) /* battery */
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#define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */
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#define ISL1208_REG_INT 0x08
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#define ISL1208_REG_09 0x09 /* reserved */
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#define ISL1208_REG_ATR 0x0a
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#define ISL1208_REG_DTR 0x0b
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/* alarm section */
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#define ISL1208_REG_SCA 0x0c
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#define ISL1208_REG_MNA 0x0d
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#define ISL1208_REG_HRA 0x0e
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#define ISL1208_REG_DTA 0x0f
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#define ISL1208_REG_MOA 0x10
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#define ISL1208_REG_DWA 0x11
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#define ISL1208_ALARM_SECTION_LEN 6
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/* user section */
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#define ISL1208_REG_USR1 0x12
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#define ISL1208_REG_USR2 0x13
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#define ISL1208_USR_SECTION_LEN 2
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static struct i2c_driver isl1208_driver;
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/* block read */
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static int
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isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
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unsigned len)
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{
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u8 reg_addr[1] = { reg };
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struct i2c_msg msgs[2] = {
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{client->addr, 0, sizeof(reg_addr), reg_addr}
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,
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{client->addr, I2C_M_RD, len, buf}
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};
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int ret;
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BUG_ON(reg > ISL1208_REG_USR2);
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BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
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ret = i2c_transfer(client->adapter, msgs, 2);
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if (ret > 0)
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ret = 0;
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return ret;
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}
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/* block write */
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static int
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isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
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unsigned len)
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{
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u8 i2c_buf[ISL1208_REG_USR2 + 2];
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struct i2c_msg msgs[1] = {
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{client->addr, 0, len + 1, i2c_buf}
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};
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int ret;
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BUG_ON(reg > ISL1208_REG_USR2);
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BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
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i2c_buf[0] = reg;
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memcpy(&i2c_buf[1], &buf[0], len);
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ret = i2c_transfer(client->adapter, msgs, 1);
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if (ret > 0)
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ret = 0;
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return ret;
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}
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/* simple check to see wether we have a isl1208 */
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static int
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isl1208_i2c_validate_client(struct i2c_client *client)
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{
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u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
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u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
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0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
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};
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int i;
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int ret;
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ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
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if (ret < 0)
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return ret;
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for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
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if (regs[i] & zero_mask[i]) /* check if bits are cleared */
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return -ENODEV;
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}
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return 0;
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}
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static int
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isl1208_i2c_get_sr(struct i2c_client *client)
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{
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int sr = i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
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if (sr < 0)
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return -EIO;
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return sr;
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}
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static int
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isl1208_i2c_get_atr(struct i2c_client *client)
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{
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int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
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if (atr < 0)
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return atr;
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/* The 6bit value in the ATR register controls the load
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* capacitance C_load * in steps of 0.25pF
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*
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* bit (1<<5) of the ATR register is inverted
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*
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* C_load(ATR=0x20) = 4.50pF
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* C_load(ATR=0x00) = 12.50pF
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* C_load(ATR=0x1f) = 20.25pF
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*
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*/
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atr &= 0x3f; /* mask out lsb */
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atr ^= 1 << 5; /* invert 6th bit */
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atr += 2 * 9; /* add offset of 4.5pF; unit[atr] = 0.25pF */
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return atr;
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}
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static int
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isl1208_i2c_get_dtr(struct i2c_client *client)
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{
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int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
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if (dtr < 0)
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return -EIO;
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/* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
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dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
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return dtr;
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}
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static int
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isl1208_i2c_get_usr(struct i2c_client *client)
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{
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u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
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int ret;
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ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
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ISL1208_USR_SECTION_LEN);
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if (ret < 0)
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return ret;
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return (buf[1] << 8) | buf[0];
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}
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static int
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isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
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{
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u8 buf[ISL1208_USR_SECTION_LEN];
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buf[0] = usr & 0xff;
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buf[1] = (usr >> 8) & 0xff;
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return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
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ISL1208_USR_SECTION_LEN);
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}
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static int
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isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
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{
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struct i2c_client *const client = to_i2c_client(dev);
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int sr, dtr, atr, usr;
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sr = isl1208_i2c_get_sr(client);
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if (sr < 0) {
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dev_err(&client->dev, "%s: reading SR failed\n", __func__);
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return sr;
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}
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seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
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(sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
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(sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
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(sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
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(sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
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(sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
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(sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
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seq_printf(seq, "batt_status\t: %s\n",
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(sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
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dtr = isl1208_i2c_get_dtr(client);
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if (dtr >= 0 - 1)
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seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);
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atr = isl1208_i2c_get_atr(client);
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if (atr >= 0)
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seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
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atr >> 2, (atr & 0x3) * 25);
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usr = isl1208_i2c_get_usr(client);
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if (usr >= 0)
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seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
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return 0;
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}
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static int
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isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
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{
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int sr;
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u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
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sr = isl1208_i2c_get_sr(client);
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if (sr < 0) {
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dev_err(&client->dev, "%s: reading SR failed\n", __func__);
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return -EIO;
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}
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sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
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if (sr < 0) {
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dev_err(&client->dev, "%s: reading RTC section failed\n",
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__func__);
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return sr;
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}
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tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SC]);
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tm->tm_min = BCD2BIN(regs[ISL1208_REG_MN]);
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/* HR field has a more complex interpretation */
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{
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const u8 _hr = regs[ISL1208_REG_HR];
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if (_hr & ISL1208_REG_HR_MIL) /* 24h format */
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tm->tm_hour = BCD2BIN(_hr & 0x3f);
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else {
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/* 12h format */
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tm->tm_hour = BCD2BIN(_hr & 0x1f);
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if (_hr & ISL1208_REG_HR_PM) /* PM flag set */
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tm->tm_hour += 12;
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}
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}
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tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DT]);
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tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
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tm->tm_year = BCD2BIN(regs[ISL1208_REG_YR]) + 100;
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tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DW]);
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return 0;
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}
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static int
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isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
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{
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struct rtc_time *const tm = &alarm->time;
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u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
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int sr;
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sr = isl1208_i2c_get_sr(client);
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if (sr < 0) {
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dev_err(&client->dev, "%s: reading SR failed\n", __func__);
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return sr;
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}
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sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
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ISL1208_ALARM_SECTION_LEN);
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if (sr < 0) {
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dev_err(&client->dev, "%s: reading alarm section failed\n",
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__func__);
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return sr;
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}
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/* MSB of each alarm register is an enable bit */
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tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
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tm->tm_min = BCD2BIN(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
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tm->tm_hour = BCD2BIN(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
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tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
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tm->tm_mon =
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BCD2BIN(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
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tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
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return 0;
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}
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static int
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isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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return isl1208_i2c_read_time(to_i2c_client(dev), tm);
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}
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static int
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isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
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{
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int sr;
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u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
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regs[ISL1208_REG_SC] = BIN2BCD(tm->tm_sec);
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regs[ISL1208_REG_MN] = BIN2BCD(tm->tm_min);
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regs[ISL1208_REG_HR] = BIN2BCD(tm->tm_hour) | ISL1208_REG_HR_MIL;
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regs[ISL1208_REG_DT] = BIN2BCD(tm->tm_mday);
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regs[ISL1208_REG_MO] = BIN2BCD(tm->tm_mon + 1);
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regs[ISL1208_REG_YR] = BIN2BCD(tm->tm_year - 100);
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regs[ISL1208_REG_DW] = BIN2BCD(tm->tm_wday & 7);
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sr = isl1208_i2c_get_sr(client);
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if (sr < 0) {
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dev_err(&client->dev, "%s: reading SR failed\n", __func__);
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return sr;
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}
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/* set WRTC */
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sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
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sr | ISL1208_REG_SR_WRTC);
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if (sr < 0) {
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dev_err(&client->dev, "%s: writing SR failed\n", __func__);
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return sr;
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}
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/* write RTC registers */
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sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
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if (sr < 0) {
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dev_err(&client->dev, "%s: writing RTC section failed\n",
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__func__);
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return sr;
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}
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/* clear WRTC again */
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sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
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sr & ~ISL1208_REG_SR_WRTC);
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if (sr < 0) {
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dev_err(&client->dev, "%s: writing SR failed\n", __func__);
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return sr;
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}
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return 0;
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}
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static int
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isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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return isl1208_i2c_set_time(to_i2c_client(dev), tm);
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}
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static int
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isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
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{
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return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
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}
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static const struct rtc_class_ops isl1208_rtc_ops = {
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.proc = isl1208_rtc_proc,
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.read_time = isl1208_rtc_read_time,
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.set_time = isl1208_rtc_set_time,
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.read_alarm = isl1208_rtc_read_alarm,
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/*.set_alarm = isl1208_rtc_set_alarm, */
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};
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/* sysfs interface */
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static ssize_t
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isl1208_sysfs_show_atrim(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int atr = isl1208_i2c_get_atr(to_i2c_client(dev));
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if (atr < 0)
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return atr;
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return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
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}
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static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
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static ssize_t
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isl1208_sysfs_show_dtrim(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
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if (dtr < 0)
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return dtr;
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return sprintf(buf, "%d ppm\n", dtr);
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}
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static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
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static ssize_t
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isl1208_sysfs_show_usr(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int usr = isl1208_i2c_get_usr(to_i2c_client(dev));
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if (usr < 0)
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return usr;
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return sprintf(buf, "0x%.4x\n", usr);
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}
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static ssize_t
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isl1208_sysfs_store_usr(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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int usr = -1;
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if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
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if (sscanf(buf, "%x", &usr) != 1)
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return -EINVAL;
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} else {
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if (sscanf(buf, "%d", &usr) != 1)
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return -EINVAL;
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}
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if (usr < 0 || usr > 0xffff)
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return -EINVAL;
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return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
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}
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static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
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isl1208_sysfs_store_usr);
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static int
|
|
isl1208_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;
|
|
}
|
|
|
|
err = device_create_file(dev, &dev_attr_usr);
|
|
if (err) {
|
|
device_remove_file(dev, &dev_attr_atrim);
|
|
device_remove_file(dev, &dev_attr_dtrim);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
isl1208_sysfs_unregister(struct device *dev)
|
|
{
|
|
device_remove_file(dev, &dev_attr_atrim);
|
|
device_remove_file(dev, &dev_attr_atrim);
|
|
device_remove_file(dev, &dev_attr_usr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
isl1208_probe(struct i2c_client *client)
|
|
{
|
|
int rc = 0;
|
|
struct rtc_device *rtc;
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
|
|
return -ENODEV;
|
|
|
|
if (isl1208_i2c_validate_client(client) < 0)
|
|
return -ENODEV;
|
|
|
|
dev_info(&client->dev,
|
|
"chip found, driver version " DRV_VERSION "\n");
|
|
|
|
rtc = rtc_device_register(isl1208_driver.driver.name,
|
|
&client->dev, &isl1208_rtc_ops,
|
|
THIS_MODULE);
|
|
if (IS_ERR(rtc))
|
|
return PTR_ERR(rtc);
|
|
|
|
i2c_set_clientdata(client, rtc);
|
|
|
|
rc = isl1208_i2c_get_sr(client);
|
|
if (rc < 0) {
|
|
dev_err(&client->dev, "reading status failed\n");
|
|
goto exit_unregister;
|
|
}
|
|
|
|
if (rc & ISL1208_REG_SR_RTCF)
|
|
dev_warn(&client->dev, "rtc power failure detected, "
|
|
"please set clock.\n");
|
|
|
|
rc = isl1208_sysfs_register(&client->dev);
|
|
if (rc)
|
|
goto exit_unregister;
|
|
|
|
return 0;
|
|
|
|
exit_unregister:
|
|
rtc_device_unregister(rtc);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int
|
|
isl1208_remove(struct i2c_client *client)
|
|
{
|
|
struct rtc_device *rtc = i2c_get_clientdata(client);
|
|
|
|
isl1208_sysfs_unregister(&client->dev);
|
|
rtc_device_unregister(rtc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct i2c_driver isl1208_driver = {
|
|
.driver = {
|
|
.name = "rtc-isl1208",
|
|
},
|
|
.probe = isl1208_probe,
|
|
.remove = isl1208_remove,
|
|
};
|
|
|
|
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);
|