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Based on 2 normalized pattern(s): 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 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 # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
334 lines
7.7 KiB
C
334 lines
7.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Driver for TI BQ32000 RTC.
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*
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* Copyright (C) 2009 Semihalf.
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* Copyright (C) 2014 Pavel Machek <pavel@denx.de>
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*
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* You can get hardware description at
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* http://www.ti.com/lit/ds/symlink/bq32000.pdf
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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/rtc.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/bcd.h>
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#define BQ32K_SECONDS 0x00 /* Seconds register address */
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#define BQ32K_SECONDS_MASK 0x7F /* Mask over seconds value */
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#define BQ32K_STOP 0x80 /* Oscillator Stop flat */
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#define BQ32K_MINUTES 0x01 /* Minutes register address */
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#define BQ32K_MINUTES_MASK 0x7F /* Mask over minutes value */
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#define BQ32K_OF 0x80 /* Oscillator Failure flag */
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#define BQ32K_HOURS_MASK 0x3F /* Mask over hours value */
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#define BQ32K_CENT 0x40 /* Century flag */
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#define BQ32K_CENT_EN 0x80 /* Century flag enable bit */
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#define BQ32K_CALIBRATION 0x07 /* CAL_CFG1, calibration and control */
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#define BQ32K_TCH2 0x08 /* Trickle charge enable */
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#define BQ32K_CFG2 0x09 /* Trickle charger control */
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#define BQ32K_TCFE BIT(6) /* Trickle charge FET bypass */
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#define MAX_LEN 10 /* Maximum number of consecutive
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* register for this particular RTC.
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*/
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struct bq32k_regs {
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uint8_t seconds;
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uint8_t minutes;
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uint8_t cent_hours;
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uint8_t day;
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uint8_t date;
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uint8_t month;
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uint8_t years;
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};
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static struct i2c_driver bq32k_driver;
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static int bq32k_read(struct device *dev, void *data, uint8_t off, uint8_t len)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct i2c_msg msgs[] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1,
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.buf = &off,
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}, {
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.addr = client->addr,
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.flags = I2C_M_RD,
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.len = len,
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.buf = data,
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}
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};
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if (i2c_transfer(client->adapter, msgs, 2) == 2)
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return 0;
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return -EIO;
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}
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static int bq32k_write(struct device *dev, void *data, uint8_t off, uint8_t len)
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{
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struct i2c_client *client = to_i2c_client(dev);
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uint8_t buffer[MAX_LEN + 1];
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buffer[0] = off;
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memcpy(&buffer[1], data, len);
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if (i2c_master_send(client, buffer, len + 1) == len + 1)
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return 0;
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return -EIO;
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}
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static int bq32k_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct bq32k_regs regs;
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int error;
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error = bq32k_read(dev, ®s, 0, sizeof(regs));
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if (error)
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return error;
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/*
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* In case of oscillator failure, the register contents should be
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* considered invalid. The flag is cleared the next time the RTC is set.
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*/
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if (regs.minutes & BQ32K_OF)
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return -EINVAL;
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tm->tm_sec = bcd2bin(regs.seconds & BQ32K_SECONDS_MASK);
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tm->tm_min = bcd2bin(regs.minutes & BQ32K_MINUTES_MASK);
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tm->tm_hour = bcd2bin(regs.cent_hours & BQ32K_HOURS_MASK);
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tm->tm_mday = bcd2bin(regs.date);
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tm->tm_wday = bcd2bin(regs.day) - 1;
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tm->tm_mon = bcd2bin(regs.month) - 1;
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tm->tm_year = bcd2bin(regs.years) +
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((regs.cent_hours & BQ32K_CENT) ? 100 : 0);
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return 0;
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}
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static int bq32k_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct bq32k_regs regs;
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regs.seconds = bin2bcd(tm->tm_sec);
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regs.minutes = bin2bcd(tm->tm_min);
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regs.cent_hours = bin2bcd(tm->tm_hour) | BQ32K_CENT_EN;
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regs.day = bin2bcd(tm->tm_wday + 1);
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regs.date = bin2bcd(tm->tm_mday);
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regs.month = bin2bcd(tm->tm_mon + 1);
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if (tm->tm_year >= 100) {
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regs.cent_hours |= BQ32K_CENT;
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regs.years = bin2bcd(tm->tm_year - 100);
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} else
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regs.years = bin2bcd(tm->tm_year);
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return bq32k_write(dev, ®s, 0, sizeof(regs));
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}
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static const struct rtc_class_ops bq32k_rtc_ops = {
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.read_time = bq32k_rtc_read_time,
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.set_time = bq32k_rtc_set_time,
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};
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static int trickle_charger_of_init(struct device *dev, struct device_node *node)
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{
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unsigned char reg;
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int error;
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u32 ohms = 0;
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if (of_property_read_u32(node, "trickle-resistor-ohms" , &ohms))
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return 0;
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switch (ohms) {
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case 180+940:
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/*
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* TCHE[3:0] == 0x05, TCH2 == 1, TCFE == 0 (charging
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* over diode and 940ohm resistor)
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*/
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if (of_property_read_bool(node, "trickle-diode-disable")) {
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dev_err(dev, "diode and resistor mismatch\n");
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return -EINVAL;
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}
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reg = 0x05;
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break;
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case 180+20000:
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/* diode disabled */
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if (!of_property_read_bool(node, "trickle-diode-disable")) {
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dev_err(dev, "bq32k: diode and resistor mismatch\n");
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return -EINVAL;
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}
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reg = 0x45;
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break;
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default:
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dev_err(dev, "invalid resistor value (%d)\n", ohms);
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return -EINVAL;
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}
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error = bq32k_write(dev, ®, BQ32K_CFG2, 1);
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if (error)
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return error;
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reg = 0x20;
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error = bq32k_write(dev, ®, BQ32K_TCH2, 1);
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if (error)
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return error;
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dev_info(dev, "Enabled trickle RTC battery charge.\n");
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return 0;
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}
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static ssize_t bq32k_sysfs_show_tricklecharge_bypass(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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int reg, error;
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error = bq32k_read(dev, ®, BQ32K_CFG2, 1);
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if (error)
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return error;
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return sprintf(buf, "%d\n", (reg & BQ32K_TCFE) ? 1 : 0);
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}
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static ssize_t bq32k_sysfs_store_tricklecharge_bypass(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 reg, enable, error;
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if (kstrtoint(buf, 0, &enable))
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return -EINVAL;
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error = bq32k_read(dev, ®, BQ32K_CFG2, 1);
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if (error)
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return error;
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if (enable) {
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reg |= BQ32K_TCFE;
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error = bq32k_write(dev, ®, BQ32K_CFG2, 1);
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if (error)
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return error;
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dev_info(dev, "Enabled trickle charge FET bypass.\n");
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} else {
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reg &= ~BQ32K_TCFE;
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error = bq32k_write(dev, ®, BQ32K_CFG2, 1);
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if (error)
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return error;
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dev_info(dev, "Disabled trickle charge FET bypass.\n");
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}
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return count;
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}
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static DEVICE_ATTR(trickle_charge_bypass, 0644,
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bq32k_sysfs_show_tricklecharge_bypass,
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bq32k_sysfs_store_tricklecharge_bypass);
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static int bq32k_sysfs_register(struct device *dev)
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{
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return device_create_file(dev, &dev_attr_trickle_charge_bypass);
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}
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static void bq32k_sysfs_unregister(struct device *dev)
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{
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device_remove_file(dev, &dev_attr_trickle_charge_bypass);
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}
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static int bq32k_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct device *dev = &client->dev;
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struct rtc_device *rtc;
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uint8_t reg;
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int error;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
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return -ENODEV;
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/* Check Oscillator Stop flag */
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error = bq32k_read(dev, ®, BQ32K_SECONDS, 1);
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if (!error && (reg & BQ32K_STOP)) {
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dev_warn(dev, "Oscillator was halted. Restarting...\n");
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reg &= ~BQ32K_STOP;
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error = bq32k_write(dev, ®, BQ32K_SECONDS, 1);
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}
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if (error)
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return error;
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/* Check Oscillator Failure flag */
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error = bq32k_read(dev, ®, BQ32K_MINUTES, 1);
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if (error)
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return error;
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if (reg & BQ32K_OF)
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dev_warn(dev, "Oscillator Failure. Check RTC battery.\n");
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if (client->dev.of_node)
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trickle_charger_of_init(dev, client->dev.of_node);
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rtc = devm_rtc_device_register(&client->dev, bq32k_driver.driver.name,
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&bq32k_rtc_ops, THIS_MODULE);
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if (IS_ERR(rtc))
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return PTR_ERR(rtc);
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error = bq32k_sysfs_register(&client->dev);
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if (error) {
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dev_err(&client->dev,
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"Unable to create sysfs entries for rtc bq32000\n");
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return error;
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}
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i2c_set_clientdata(client, rtc);
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return 0;
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}
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static int bq32k_remove(struct i2c_client *client)
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{
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bq32k_sysfs_unregister(&client->dev);
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return 0;
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}
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static const struct i2c_device_id bq32k_id[] = {
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{ "bq32000", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, bq32k_id);
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static const struct of_device_id bq32k_of_match[] = {
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{ .compatible = "ti,bq32000" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, bq32k_of_match);
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static struct i2c_driver bq32k_driver = {
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.driver = {
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.name = "bq32k",
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.of_match_table = of_match_ptr(bq32k_of_match),
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},
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.probe = bq32k_probe,
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.remove = bq32k_remove,
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.id_table = bq32k_id,
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};
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module_i2c_driver(bq32k_driver);
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MODULE_AUTHOR("Semihalf, Piotr Ziecik <kosmo@semihalf.com>");
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MODULE_DESCRIPTION("TI BQ32000 I2C RTC driver");
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MODULE_LICENSE("GPL");
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