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523 lines
14 KiB
523 lines
14 KiB
/*
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* Real Time Clock driver for Wolfson Microelectronics WM831x
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*
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* Copyright (C) 2009 Wolfson Microelectronics PLC.
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*
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* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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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/kernel.h>
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#include <linux/time.h>
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#include <linux/rtc.h>
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#include <linux/bcd.h>
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#include <linux/interrupt.h>
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#include <linux/ioctl.h>
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#include <linux/completion.h>
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#include <linux/mfd/wm831x/core.h>
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#include <linux/delay.h>
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#include <linux/platform_device.h>
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/*
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* R16416 (0x4020) - RTC Write Counter
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*/
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#define WM831X_RTC_WR_CNT_MASK 0xFFFF /* RTC_WR_CNT - [15:0] */
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#define WM831X_RTC_WR_CNT_SHIFT 0 /* RTC_WR_CNT - [15:0] */
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#define WM831X_RTC_WR_CNT_WIDTH 16 /* RTC_WR_CNT - [15:0] */
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/*
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* R16417 (0x4021) - RTC Time 1
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*/
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#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
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#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
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#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
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/*
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* R16418 (0x4022) - RTC Time 2
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*/
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#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
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#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
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#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
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/*
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* R16419 (0x4023) - RTC Alarm 1
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*/
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#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
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#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
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#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
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/*
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* R16420 (0x4024) - RTC Alarm 2
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*/
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#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
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#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
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#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
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/*
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* R16421 (0x4025) - RTC Control
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*/
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#define WM831X_RTC_VALID 0x8000 /* RTC_VALID */
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#define WM831X_RTC_VALID_MASK 0x8000 /* RTC_VALID */
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#define WM831X_RTC_VALID_SHIFT 15 /* RTC_VALID */
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#define WM831X_RTC_VALID_WIDTH 1 /* RTC_VALID */
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#define WM831X_RTC_SYNC_BUSY 0x4000 /* RTC_SYNC_BUSY */
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#define WM831X_RTC_SYNC_BUSY_MASK 0x4000 /* RTC_SYNC_BUSY */
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#define WM831X_RTC_SYNC_BUSY_SHIFT 14 /* RTC_SYNC_BUSY */
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#define WM831X_RTC_SYNC_BUSY_WIDTH 1 /* RTC_SYNC_BUSY */
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#define WM831X_RTC_ALM_ENA 0x0400 /* RTC_ALM_ENA */
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#define WM831X_RTC_ALM_ENA_MASK 0x0400 /* RTC_ALM_ENA */
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#define WM831X_RTC_ALM_ENA_SHIFT 10 /* RTC_ALM_ENA */
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#define WM831X_RTC_ALM_ENA_WIDTH 1 /* RTC_ALM_ENA */
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#define WM831X_RTC_PINT_FREQ_MASK 0x0070 /* RTC_PINT_FREQ - [6:4] */
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#define WM831X_RTC_PINT_FREQ_SHIFT 4 /* RTC_PINT_FREQ - [6:4] */
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#define WM831X_RTC_PINT_FREQ_WIDTH 3 /* RTC_PINT_FREQ - [6:4] */
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/*
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* R16422 (0x4026) - RTC Trim
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*/
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#define WM831X_RTC_TRIM_MASK 0x03FF /* RTC_TRIM - [9:0] */
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#define WM831X_RTC_TRIM_SHIFT 0 /* RTC_TRIM - [9:0] */
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#define WM831X_RTC_TRIM_WIDTH 10 /* RTC_TRIM - [9:0] */
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#define WM831X_SET_TIME_RETRIES 5
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#define WM831X_GET_TIME_RETRIES 5
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struct wm831x_rtc {
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struct wm831x *wm831x;
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struct rtc_device *rtc;
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unsigned int alarm_enabled:1;
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};
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/*
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* Read current time and date in RTC
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*/
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static int wm831x_rtc_readtime(struct device *dev, struct rtc_time *tm)
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{
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struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
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struct wm831x *wm831x = wm831x_rtc->wm831x;
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u16 time1[2], time2[2];
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int ret;
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int count = 0;
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/* Has the RTC been programmed? */
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ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
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if (ret < 0) {
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dev_err(dev, "Failed to read RTC control: %d\n", ret);
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return ret;
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}
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if (!(ret & WM831X_RTC_VALID)) {
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dev_dbg(dev, "RTC not yet configured\n");
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return -EINVAL;
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}
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/* Read twice to make sure we don't read a corrupt, partially
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* incremented, value.
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*/
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do {
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ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
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2, time1);
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if (ret != 0)
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continue;
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ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
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2, time2);
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if (ret != 0)
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continue;
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if (memcmp(time1, time2, sizeof(time1)) == 0) {
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u32 time = (time1[0] << 16) | time1[1];
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rtc_time_to_tm(time, tm);
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return rtc_valid_tm(tm);
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}
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} while (++count < WM831X_GET_TIME_RETRIES);
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dev_err(dev, "Timed out reading current time\n");
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return -EIO;
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}
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/*
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* Set current time and date in RTC
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*/
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static int wm831x_rtc_set_mmss(struct device *dev, unsigned long time)
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{
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struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
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struct wm831x *wm831x = wm831x_rtc->wm831x;
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struct rtc_time new_tm;
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unsigned long new_time;
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int ret;
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int count = 0;
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ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_1,
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(time >> 16) & 0xffff);
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if (ret < 0) {
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dev_err(dev, "Failed to write TIME_1: %d\n", ret);
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return ret;
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}
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ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_2, time & 0xffff);
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if (ret < 0) {
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dev_err(dev, "Failed to write TIME_2: %d\n", ret);
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return ret;
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}
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/* Wait for the update to complete - should happen first time
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* round but be conservative.
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*/
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do {
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msleep(1);
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ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
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if (ret < 0)
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ret = WM831X_RTC_SYNC_BUSY;
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} while (!(ret & WM831X_RTC_SYNC_BUSY) &&
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++count < WM831X_SET_TIME_RETRIES);
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if (ret & WM831X_RTC_SYNC_BUSY) {
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dev_err(dev, "Timed out writing RTC update\n");
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return -EIO;
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}
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/* Check that the update was accepted; security features may
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* have caused the update to be ignored.
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*/
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ret = wm831x_rtc_readtime(dev, &new_tm);
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if (ret < 0)
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return ret;
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ret = rtc_tm_to_time(&new_tm, &new_time);
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if (ret < 0) {
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dev_err(dev, "Failed to convert time: %d\n", ret);
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return ret;
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}
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/* Allow a second of change in case of tick */
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if (new_time - time > 1) {
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dev_err(dev, "RTC update not permitted by hardware\n");
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return -EPERM;
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}
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return 0;
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}
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/*
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* Read alarm time and date in RTC
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*/
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static int wm831x_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
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int ret;
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u16 data[2];
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u32 time;
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ret = wm831x_bulk_read(wm831x_rtc->wm831x, WM831X_RTC_ALARM_1,
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2, data);
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if (ret != 0) {
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dev_err(dev, "Failed to read alarm time: %d\n", ret);
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return ret;
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}
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time = (data[0] << 16) | data[1];
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rtc_time_to_tm(time, &alrm->time);
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ret = wm831x_reg_read(wm831x_rtc->wm831x, WM831X_RTC_CONTROL);
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if (ret < 0) {
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dev_err(dev, "Failed to read RTC control: %d\n", ret);
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return ret;
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}
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if (ret & WM831X_RTC_ALM_ENA)
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alrm->enabled = 1;
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else
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alrm->enabled = 0;
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return 0;
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}
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static int wm831x_rtc_stop_alarm(struct wm831x_rtc *wm831x_rtc)
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{
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wm831x_rtc->alarm_enabled = 0;
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return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
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WM831X_RTC_ALM_ENA, 0);
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}
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static int wm831x_rtc_start_alarm(struct wm831x_rtc *wm831x_rtc)
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{
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wm831x_rtc->alarm_enabled = 1;
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return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
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WM831X_RTC_ALM_ENA, WM831X_RTC_ALM_ENA);
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}
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static int wm831x_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
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struct wm831x *wm831x = wm831x_rtc->wm831x;
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int ret;
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unsigned long time;
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ret = rtc_tm_to_time(&alrm->time, &time);
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if (ret < 0) {
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dev_err(dev, "Failed to convert time: %d\n", ret);
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return ret;
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}
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ret = wm831x_rtc_stop_alarm(wm831x_rtc);
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if (ret < 0) {
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dev_err(dev, "Failed to stop alarm: %d\n", ret);
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return ret;
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}
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ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_1,
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(time >> 16) & 0xffff);
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if (ret < 0) {
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dev_err(dev, "Failed to write ALARM_1: %d\n", ret);
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return ret;
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}
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ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_2, time & 0xffff);
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if (ret < 0) {
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dev_err(dev, "Failed to write ALARM_2: %d\n", ret);
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return ret;
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}
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if (alrm->enabled) {
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ret = wm831x_rtc_start_alarm(wm831x_rtc);
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if (ret < 0) {
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dev_err(dev, "Failed to start alarm: %d\n", ret);
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return ret;
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}
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}
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return 0;
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}
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static int wm831x_rtc_alarm_irq_enable(struct device *dev,
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unsigned int enabled)
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{
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struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
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if (enabled)
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return wm831x_rtc_start_alarm(wm831x_rtc);
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else
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return wm831x_rtc_stop_alarm(wm831x_rtc);
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}
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static int wm831x_rtc_update_irq_enable(struct device *dev,
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unsigned int enabled)
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{
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struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
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int val;
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if (enabled)
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val = 1 << WM831X_RTC_PINT_FREQ_SHIFT;
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else
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val = 0;
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return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
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WM831X_RTC_PINT_FREQ_MASK, val);
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}
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static irqreturn_t wm831x_alm_irq(int irq, void *data)
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{
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struct wm831x_rtc *wm831x_rtc = data;
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rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_AF);
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return IRQ_HANDLED;
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}
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static irqreturn_t wm831x_per_irq(int irq, void *data)
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{
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struct wm831x_rtc *wm831x_rtc = data;
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rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_UF);
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return IRQ_HANDLED;
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}
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static const struct rtc_class_ops wm831x_rtc_ops = {
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.read_time = wm831x_rtc_readtime,
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.set_mmss = wm831x_rtc_set_mmss,
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.read_alarm = wm831x_rtc_readalarm,
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.set_alarm = wm831x_rtc_setalarm,
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.alarm_irq_enable = wm831x_rtc_alarm_irq_enable,
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.update_irq_enable = wm831x_rtc_update_irq_enable,
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};
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#ifdef CONFIG_PM
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/* Turn off the alarm if it should not be a wake source. */
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static int wm831x_rtc_suspend(struct device *dev)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
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int ret, enable;
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if (wm831x_rtc->alarm_enabled && device_may_wakeup(&pdev->dev))
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enable = WM831X_RTC_ALM_ENA;
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else
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enable = 0;
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ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
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WM831X_RTC_ALM_ENA, enable);
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if (ret != 0)
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dev_err(&pdev->dev, "Failed to update RTC alarm: %d\n", ret);
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return 0;
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}
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/* Enable the alarm if it should be enabled (in case it was disabled to
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* prevent use as a wake source).
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*/
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static int wm831x_rtc_resume(struct device *dev)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
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int ret;
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if (wm831x_rtc->alarm_enabled) {
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ret = wm831x_rtc_start_alarm(wm831x_rtc);
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if (ret != 0)
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dev_err(&pdev->dev,
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"Failed to restart RTC alarm: %d\n", ret);
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}
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return 0;
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}
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/* Unconditionally disable the alarm */
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static int wm831x_rtc_freeze(struct device *dev)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
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int ret;
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ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
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WM831X_RTC_ALM_ENA, 0);
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if (ret != 0)
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dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", ret);
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return 0;
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}
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#else
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#define wm831x_rtc_suspend NULL
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#define wm831x_rtc_resume NULL
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#define wm831x_rtc_freeze NULL
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#endif
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static int wm831x_rtc_probe(struct platform_device *pdev)
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{
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struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
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struct wm831x_rtc *wm831x_rtc;
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int per_irq = platform_get_irq_byname(pdev, "PER");
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int alm_irq = platform_get_irq_byname(pdev, "ALM");
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int ret = 0;
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wm831x_rtc = kzalloc(sizeof(*wm831x_rtc), GFP_KERNEL);
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if (wm831x_rtc == NULL)
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return -ENOMEM;
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platform_set_drvdata(pdev, wm831x_rtc);
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wm831x_rtc->wm831x = wm831x;
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ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
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if (ret < 0) {
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dev_err(&pdev->dev, "Failed to read RTC control: %d\n", ret);
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goto err;
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}
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if (ret & WM831X_RTC_ALM_ENA)
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wm831x_rtc->alarm_enabled = 1;
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device_init_wakeup(&pdev->dev, 1);
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wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev,
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&wm831x_rtc_ops, THIS_MODULE);
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if (IS_ERR(wm831x_rtc->rtc)) {
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ret = PTR_ERR(wm831x_rtc->rtc);
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goto err;
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}
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ret = wm831x_request_irq(wm831x, per_irq, wm831x_per_irq,
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IRQF_TRIGGER_RISING, "wm831x_rtc_per",
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wm831x_rtc);
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if (ret != 0) {
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dev_err(&pdev->dev, "Failed to request periodic IRQ %d: %d\n",
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per_irq, ret);
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}
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ret = wm831x_request_irq(wm831x, alm_irq, wm831x_alm_irq,
|
|
IRQF_TRIGGER_RISING, "wm831x_rtc_alm",
|
|
wm831x_rtc);
|
|
if (ret != 0) {
|
|
dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
|
|
alm_irq, ret);
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
kfree(wm831x_rtc);
|
|
return ret;
|
|
}
|
|
|
|
static int __devexit wm831x_rtc_remove(struct platform_device *pdev)
|
|
{
|
|
struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev);
|
|
int per_irq = platform_get_irq_byname(pdev, "PER");
|
|
int alm_irq = platform_get_irq_byname(pdev, "ALM");
|
|
|
|
wm831x_free_irq(wm831x_rtc->wm831x, alm_irq, wm831x_rtc);
|
|
wm831x_free_irq(wm831x_rtc->wm831x, per_irq, wm831x_rtc);
|
|
rtc_device_unregister(wm831x_rtc->rtc);
|
|
kfree(wm831x_rtc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct dev_pm_ops wm831x_rtc_pm_ops = {
|
|
.suspend = wm831x_rtc_suspend,
|
|
.resume = wm831x_rtc_resume,
|
|
|
|
.freeze = wm831x_rtc_freeze,
|
|
.thaw = wm831x_rtc_resume,
|
|
.restore = wm831x_rtc_resume,
|
|
|
|
.poweroff = wm831x_rtc_suspend,
|
|
};
|
|
|
|
static struct platform_driver wm831x_rtc_driver = {
|
|
.probe = wm831x_rtc_probe,
|
|
.remove = __devexit_p(wm831x_rtc_remove),
|
|
.driver = {
|
|
.name = "wm831x-rtc",
|
|
.pm = &wm831x_rtc_pm_ops,
|
|
},
|
|
};
|
|
|
|
static int __init wm831x_rtc_init(void)
|
|
{
|
|
return platform_driver_register(&wm831x_rtc_driver);
|
|
}
|
|
module_init(wm831x_rtc_init);
|
|
|
|
static void __exit wm831x_rtc_exit(void)
|
|
{
|
|
platform_driver_unregister(&wm831x_rtc_driver);
|
|
}
|
|
module_exit(wm831x_rtc_exit);
|
|
|
|
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
|
|
MODULE_DESCRIPTION("RTC driver for the WM831x series PMICs");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:wm831x-rtc");
|
|
|