forked from Minki/linux
rtc: pic32: Add PIC32 real time clock driver
This driver adds support for the PIC32 real time clock and calendar peripheral: - reading and setting time - alarms provided by dedicated IRQ Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This commit is contained in:
Joshua Henderson
Alexandre Belloni
parent
af556c11f0
commit
51aa905c91
@ -1641,6 +1641,16 @@ config RTC_DRV_XGENE
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This driver can also be built as a module, if so, the module
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will be called "rtc-xgene".
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config RTC_DRV_PIC32
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tristate "Microchip PIC32 RTC"
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depends on MACH_PIC32
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default y
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help
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If you say yes here you get support for the PIC32 RTC module.
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This driver can also be built as a module. If so, the module
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will be called rtc-pic32
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comment "HID Sensor RTC drivers"
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config RTC_DRV_HID_SENSOR_TIME
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@ -112,6 +112,7 @@ obj-$(CONFIG_RTC_DRV_PCF85063) += rtc-pcf85063.o
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obj-$(CONFIG_RTC_DRV_PCF8523) += rtc-pcf8523.o
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obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
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obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o
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obj-$(CONFIG_RTC_DRV_PIC32) += rtc-pic32.o
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obj-$(CONFIG_RTC_DRV_PL030) += rtc-pl030.o
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obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o
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obj-$(CONFIG_RTC_DRV_PM8XXX) += rtc-pm8xxx.o
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411
drivers/rtc/rtc-pic32.c
Normal file
411
drivers/rtc/rtc-pic32.c
Normal file
@ -0,0 +1,411 @@
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/*
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* PIC32 RTC driver
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*
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* Joshua Henderson <joshua.henderson@microchip.com>
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* Copyright (C) 2016 Microchip Technology Inc. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <linux/clk.h>
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#include <linux/rtc.h>
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#include <linux/bcd.h>
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#include <asm/mach-pic32/pic32.h>
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#define PIC32_RTCCON 0x00
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#define PIC32_RTCCON_ON BIT(15)
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#define PIC32_RTCCON_SIDL BIT(13)
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#define PIC32_RTCCON_RTCCLKSEL (3 << 9)
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#define PIC32_RTCCON_RTCCLKON BIT(6)
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#define PIC32_RTCCON_RTCWREN BIT(3)
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#define PIC32_RTCCON_RTCSYNC BIT(2)
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#define PIC32_RTCCON_HALFSEC BIT(1)
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#define PIC32_RTCCON_RTCOE BIT(0)
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#define PIC32_RTCALRM 0x10
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#define PIC32_RTCALRM_ALRMEN BIT(15)
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#define PIC32_RTCALRM_CHIME BIT(14)
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#define PIC32_RTCALRM_PIV BIT(13)
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#define PIC32_RTCALRM_ALARMSYNC BIT(12)
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#define PIC32_RTCALRM_AMASK 0x0F00
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#define PIC32_RTCALRM_ARPT 0xFF
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#define PIC32_RTCHOUR 0x23
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#define PIC32_RTCMIN 0x22
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#define PIC32_RTCSEC 0x21
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#define PIC32_RTCYEAR 0x33
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#define PIC32_RTCMON 0x32
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#define PIC32_RTCDAY 0x31
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#define PIC32_ALRMTIME 0x40
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#define PIC32_ALRMDATE 0x50
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#define PIC32_ALRMHOUR 0x43
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#define PIC32_ALRMMIN 0x42
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#define PIC32_ALRMSEC 0x41
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#define PIC32_ALRMYEAR 0x53
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#define PIC32_ALRMMON 0x52
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#define PIC32_ALRMDAY 0x51
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struct pic32_rtc_dev {
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struct rtc_device *rtc;
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void __iomem *reg_base;
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struct clk *clk;
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spinlock_t alarm_lock;
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int alarm_irq;
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bool alarm_clk_enabled;
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};
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static void pic32_rtc_alarm_clk_enable(struct pic32_rtc_dev *pdata,
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bool enable)
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{
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unsigned long flags;
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spin_lock_irqsave(&pdata->alarm_lock, flags);
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if (enable) {
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if (!pdata->alarm_clk_enabled) {
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clk_enable(pdata->clk);
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pdata->alarm_clk_enabled = true;
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}
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} else {
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if (pdata->alarm_clk_enabled) {
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clk_disable(pdata->clk);
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pdata->alarm_clk_enabled = false;
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}
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}
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spin_unlock_irqrestore(&pdata->alarm_lock, flags);
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}
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static irqreturn_t pic32_rtc_alarmirq(int irq, void *id)
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{
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struct pic32_rtc_dev *pdata = (struct pic32_rtc_dev *)id;
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clk_enable(pdata->clk);
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rtc_update_irq(pdata->rtc, 1, RTC_AF | RTC_IRQF);
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clk_disable(pdata->clk);
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pic32_rtc_alarm_clk_enable(pdata, false);
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return IRQ_HANDLED;
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}
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static int pic32_rtc_setaie(struct device *dev, unsigned int enabled)
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{
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struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
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void __iomem *base = pdata->reg_base;
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clk_enable(pdata->clk);
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writel(PIC32_RTCALRM_ALRMEN,
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base + (enabled ? PIC32_SET(PIC32_RTCALRM) :
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PIC32_CLR(PIC32_RTCALRM)));
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clk_disable(pdata->clk);
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pic32_rtc_alarm_clk_enable(pdata, enabled);
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return 0;
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}
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static int pic32_rtc_setfreq(struct device *dev, int freq)
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{
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struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
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void __iomem *base = pdata->reg_base;
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clk_enable(pdata->clk);
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writel(PIC32_RTCALRM_AMASK, base + PIC32_CLR(PIC32_RTCALRM));
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writel(freq << 8, base + PIC32_SET(PIC32_RTCALRM));
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writel(PIC32_RTCALRM_CHIME, base + PIC32_SET(PIC32_RTCALRM));
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clk_disable(pdata->clk);
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return 0;
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}
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static int pic32_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
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{
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struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
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void __iomem *base = pdata->reg_base;
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unsigned int tries = 0;
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clk_enable(pdata->clk);
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do {
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rtc_tm->tm_hour = readb(base + PIC32_RTCHOUR);
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rtc_tm->tm_min = readb(base + PIC32_RTCMIN);
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rtc_tm->tm_mon = readb(base + PIC32_RTCMON);
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rtc_tm->tm_mday = readb(base + PIC32_RTCDAY);
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rtc_tm->tm_year = readb(base + PIC32_RTCYEAR);
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rtc_tm->tm_sec = readb(base + PIC32_RTCSEC);
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/*
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* The only way to work out whether the system was mid-update
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* when we read it is to check the second counter, and if it
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* is zero, then we re-try the entire read.
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*/
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tries += 1;
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} while (rtc_tm->tm_sec == 0 && tries < 2);
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rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
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rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
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rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
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rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
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rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon) - 1;
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rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
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rtc_tm->tm_year += 100;
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dev_dbg(dev, "read time %04d.%02d.%02d %02d:%02d:%02d\n",
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1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
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rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
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clk_disable(pdata->clk);
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return rtc_valid_tm(rtc_tm);
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}
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static int pic32_rtc_settime(struct device *dev, struct rtc_time *tm)
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{
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struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
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void __iomem *base = pdata->reg_base;
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int year = tm->tm_year - 100;
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dev_dbg(dev, "set time %04d.%02d.%02d %02d:%02d:%02d\n",
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1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
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tm->tm_hour, tm->tm_min, tm->tm_sec);
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if (year < 0 || year >= 100) {
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dev_err(dev, "rtc only supports 100 years\n");
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return -EINVAL;
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}
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clk_enable(pdata->clk);
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writeb(bin2bcd(tm->tm_sec), base + PIC32_RTCSEC);
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writeb(bin2bcd(tm->tm_min), base + PIC32_RTCMIN);
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writeb(bin2bcd(tm->tm_hour), base + PIC32_RTCHOUR);
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writeb(bin2bcd(tm->tm_mday), base + PIC32_RTCDAY);
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writeb(bin2bcd(tm->tm_mon + 1), base + PIC32_RTCMON);
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writeb(bin2bcd(year), base + PIC32_RTCYEAR);
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clk_disable(pdata->clk);
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return 0;
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}
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static int pic32_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
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struct rtc_time *alm_tm = &alrm->time;
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void __iomem *base = pdata->reg_base;
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unsigned int alm_en;
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clk_enable(pdata->clk);
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alm_tm->tm_sec = readb(base + PIC32_ALRMSEC);
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alm_tm->tm_min = readb(base + PIC32_ALRMMIN);
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alm_tm->tm_hour = readb(base + PIC32_ALRMHOUR);
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alm_tm->tm_mon = readb(base + PIC32_ALRMMON);
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alm_tm->tm_mday = readb(base + PIC32_ALRMDAY);
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alm_tm->tm_year = readb(base + PIC32_ALRMYEAR);
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alm_en = readb(base + PIC32_RTCALRM);
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alrm->enabled = (alm_en & PIC32_RTCALRM_ALRMEN) ? 1 : 0;
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dev_dbg(dev, "getalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
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alm_en,
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1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
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alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
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alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
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alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
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alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
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alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
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alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon) - 1;
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alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
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clk_disable(pdata->clk);
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return 0;
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}
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static int pic32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
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struct rtc_time *tm = &alrm->time;
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void __iomem *base = pdata->reg_base;
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clk_enable(pdata->clk);
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dev_dbg(dev, "setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
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alrm->enabled,
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1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
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tm->tm_hour, tm->tm_min, tm->tm_sec);
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writel(0x00, base + PIC32_ALRMTIME);
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writel(0x00, base + PIC32_ALRMDATE);
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pic32_rtc_setaie(dev, alrm->enabled);
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clk_disable(pdata->clk);
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return 0;
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}
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static int pic32_rtc_proc(struct device *dev, struct seq_file *seq)
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{
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struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
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void __iomem *base = pdata->reg_base;
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unsigned int repeat;
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clk_enable(pdata->clk);
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repeat = readw(base + PIC32_RTCALRM);
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repeat &= PIC32_RTCALRM_ARPT;
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seq_printf(seq, "periodic_IRQ\t: %s\n", repeat ? "yes" : "no");
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clk_disable(pdata->clk);
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return 0;
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}
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static const struct rtc_class_ops pic32_rtcops = {
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.read_time = pic32_rtc_gettime,
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.set_time = pic32_rtc_settime,
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.read_alarm = pic32_rtc_getalarm,
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.set_alarm = pic32_rtc_setalarm,
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.proc = pic32_rtc_proc,
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.alarm_irq_enable = pic32_rtc_setaie,
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};
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static void pic32_rtc_enable(struct pic32_rtc_dev *pdata, int en)
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{
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void __iomem *base = pdata->reg_base;
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if (!base)
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return;
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clk_enable(pdata->clk);
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if (!en) {
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writel(PIC32_RTCCON_ON, base + PIC32_CLR(PIC32_RTCCON));
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} else {
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pic32_syskey_unlock();
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writel(PIC32_RTCCON_RTCWREN, base + PIC32_SET(PIC32_RTCCON));
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writel(3 << 9, base + PIC32_CLR(PIC32_RTCCON));
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if (!(readl(base + PIC32_RTCCON) & PIC32_RTCCON_ON))
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writel(PIC32_RTCCON_ON, base + PIC32_SET(PIC32_RTCCON));
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}
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clk_disable(pdata->clk);
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}
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static int pic32_rtc_remove(struct platform_device *pdev)
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{
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struct pic32_rtc_dev *pdata = platform_get_drvdata(pdev);
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pic32_rtc_setaie(&pdev->dev, 0);
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clk_unprepare(pdata->clk);
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pdata->clk = NULL;
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return 0;
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}
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static int pic32_rtc_probe(struct platform_device *pdev)
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{
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struct pic32_rtc_dev *pdata;
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struct resource *res;
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int ret;
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pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return -ENOMEM;
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platform_set_drvdata(pdev, pdata);
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pdata->alarm_irq = platform_get_irq(pdev, 0);
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if (pdata->alarm_irq < 0) {
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dev_err(&pdev->dev, "no irq for alarm\n");
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return pdata->alarm_irq;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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pdata->reg_base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(pdata->reg_base))
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return PTR_ERR(pdata->reg_base);
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pdata->clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(pdata->clk)) {
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dev_err(&pdev->dev, "failed to find rtc clock source\n");
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ret = PTR_ERR(pdata->clk);
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pdata->clk = NULL;
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return ret;
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}
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spin_lock_init(&pdata->alarm_lock);
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clk_prepare_enable(pdata->clk);
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pic32_rtc_enable(pdata, 1);
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device_init_wakeup(&pdev->dev, 1);
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pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
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&pic32_rtcops,
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THIS_MODULE);
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if (IS_ERR(pdata->rtc)) {
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ret = PTR_ERR(pdata->rtc);
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goto err_nortc;
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}
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pdata->rtc->max_user_freq = 128;
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pic32_rtc_setfreq(&pdev->dev, 1);
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ret = devm_request_irq(&pdev->dev, pdata->alarm_irq,
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pic32_rtc_alarmirq, 0,
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dev_name(&pdev->dev), pdata);
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if (ret) {
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dev_err(&pdev->dev,
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"IRQ %d error %d\n", pdata->alarm_irq, ret);
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goto err_nortc;
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}
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clk_disable(pdata->clk);
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return 0;
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err_nortc:
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pic32_rtc_enable(pdata, 0);
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clk_disable_unprepare(pdata->clk);
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return ret;
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}
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static const struct of_device_id pic32_rtc_dt_ids[] = {
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{ .compatible = "microchip,pic32mzda-rtc" },
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{ /* sentinel */ }
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};
|
||||
MODULE_DEVICE_TABLE(of, pic32_rtc_dt_ids);
|
||||
|
||||
static struct platform_driver pic32_rtc_driver = {
|
||||
.probe = pic32_rtc_probe,
|
||||
.remove = pic32_rtc_remove,
|
||||
.driver = {
|
||||
.name = "pic32-rtc",
|
||||
.owner = THIS_MODULE,
|
||||
.of_match_table = of_match_ptr(pic32_rtc_dt_ids),
|
||||
},
|
||||
};
|
||||
module_platform_driver(pic32_rtc_driver);
|
||||
|
||||
MODULE_DESCRIPTION("Microchip PIC32 RTC Driver");
|
||||
MODULE_AUTHOR("Joshua Henderson <joshua.henderson@microchip.com>");
|
||||
MODULE_LICENSE("GPL");
|
||||
Loading…
Reference in New Issue
Block a user