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eb7b85853c
The BBNSM module includes a real time counter with alarm. Add a RTC driver for this function. Signed-off-by: Jacky Bai <ping.bai@nxp.com> Reviewed-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/20230215024117.3357341-3-ping.bai@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
227 lines
5.6 KiB
C
227 lines
5.6 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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//
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// Copyright 2022 NXP.
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/mfd/syscon.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/pm_wakeirq.h>
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#include <linux/regmap.h>
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#include <linux/rtc.h>
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#define BBNSM_CTRL 0x8
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#define BBNSM_INT_EN 0x10
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#define BBNSM_EVENTS 0x14
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#define BBNSM_RTC_LS 0x40
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#define BBNSM_RTC_MS 0x44
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#define BBNSM_TA 0x50
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#define RTC_EN 0x2
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#define RTC_EN_MSK 0x3
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#define TA_EN (0x2 << 2)
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#define TA_DIS (0x1 << 2)
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#define TA_EN_MSK (0x3 << 2)
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#define RTC_INT_EN 0x2
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#define TA_INT_EN (0x2 << 2)
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#define BBNSM_EVENT_TA (0x2 << 2)
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#define CNTR_TO_SECS_SH 15
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struct bbnsm_rtc {
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struct rtc_device *rtc;
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struct regmap *regmap;
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int irq;
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struct clk *clk;
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};
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static u32 bbnsm_read_counter(struct bbnsm_rtc *bbnsm)
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{
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u32 rtc_msb, rtc_lsb;
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unsigned int timeout = 100;
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u32 time;
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u32 tmp = 0;
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do {
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time = tmp;
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/* read the msb */
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regmap_read(bbnsm->regmap, BBNSM_RTC_MS, &rtc_msb);
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/* read the lsb */
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regmap_read(bbnsm->regmap, BBNSM_RTC_LS, &rtc_lsb);
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/* convert to seconds */
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tmp = (rtc_msb << 17) | (rtc_lsb >> 15);
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} while (tmp != time && --timeout);
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return time;
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}
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static int bbnsm_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
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unsigned long time;
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u32 val;
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regmap_read(bbnsm->regmap, BBNSM_CTRL, &val);
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if ((val & RTC_EN_MSK) != RTC_EN)
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return -EINVAL;
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time = bbnsm_read_counter(bbnsm);
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rtc_time64_to_tm(time, tm);
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return 0;
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}
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static int bbnsm_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
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unsigned long time = rtc_tm_to_time64(tm);
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/* disable the RTC first */
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regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, 0);
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/* write the 32bit sec time to 47 bit timer counter, leaving 15 LSBs blank */
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regmap_write(bbnsm->regmap, BBNSM_RTC_LS, time << CNTR_TO_SECS_SH);
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regmap_write(bbnsm->regmap, BBNSM_RTC_MS, time >> (32 - CNTR_TO_SECS_SH));
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/* Enable the RTC again */
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regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, RTC_EN);
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return 0;
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}
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static int bbnsm_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
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u32 bbnsm_events, bbnsm_ta;
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regmap_read(bbnsm->regmap, BBNSM_TA, &bbnsm_ta);
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rtc_time64_to_tm(bbnsm_ta, &alrm->time);
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regmap_read(bbnsm->regmap, BBNSM_EVENTS, &bbnsm_events);
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alrm->pending = (bbnsm_events & BBNSM_EVENT_TA) ? 1 : 0;
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return 0;
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}
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static int bbnsm_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
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{
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struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
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/* enable the alarm event */
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regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN_MSK, enable ? TA_EN : TA_DIS);
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/* enable the alarm interrupt */
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regmap_update_bits(bbnsm->regmap, BBNSM_INT_EN, TA_EN_MSK, enable ? TA_EN : TA_DIS);
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return 0;
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}
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static int bbnsm_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
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unsigned long time = rtc_tm_to_time64(&alrm->time);
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/* disable the alarm */
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regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN, TA_EN);
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/* write the seconds to TA */
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regmap_write(bbnsm->regmap, BBNSM_TA, time);
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return bbnsm_rtc_alarm_irq_enable(dev, alrm->enabled);
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}
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static const struct rtc_class_ops bbnsm_rtc_ops = {
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.read_time = bbnsm_rtc_read_time,
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.set_time = bbnsm_rtc_set_time,
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.read_alarm = bbnsm_rtc_read_alarm,
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.set_alarm = bbnsm_rtc_set_alarm,
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.alarm_irq_enable = bbnsm_rtc_alarm_irq_enable,
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};
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static irqreturn_t bbnsm_rtc_irq_handler(int irq, void *dev_id)
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{
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struct device *dev = dev_id;
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struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
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u32 val;
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regmap_read(bbnsm->regmap, BBNSM_EVENTS, &val);
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if (val & BBNSM_EVENT_TA) {
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bbnsm_rtc_alarm_irq_enable(dev, false);
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/* clear the alarm event */
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regmap_write_bits(bbnsm->regmap, BBNSM_EVENTS, TA_EN_MSK, BBNSM_EVENT_TA);
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rtc_update_irq(bbnsm->rtc, 1, RTC_AF | RTC_IRQF);
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return IRQ_HANDLED;
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}
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return IRQ_NONE;
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}
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static int bbnsm_rtc_probe(struct platform_device *pdev)
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{
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struct device_node *np = pdev->dev.of_node;
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struct bbnsm_rtc *bbnsm;
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int ret;
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bbnsm = devm_kzalloc(&pdev->dev, sizeof(*bbnsm), GFP_KERNEL);
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if (!bbnsm)
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return -ENOMEM;
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bbnsm->rtc = devm_rtc_allocate_device(&pdev->dev);
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if (IS_ERR(bbnsm->rtc))
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return PTR_ERR(bbnsm->rtc);
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bbnsm->regmap = syscon_node_to_regmap(np->parent);
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if (IS_ERR(bbnsm->regmap)) {
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dev_dbg(&pdev->dev, "bbnsm get regmap failed\n");
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return PTR_ERR(bbnsm->regmap);
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}
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bbnsm->irq = platform_get_irq(pdev, 0);
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if (bbnsm->irq < 0)
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return bbnsm->irq;
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platform_set_drvdata(pdev, bbnsm);
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/* clear all the pending events */
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regmap_write(bbnsm->regmap, BBNSM_EVENTS, 0x7A);
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device_init_wakeup(&pdev->dev, true);
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dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq);
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ret = devm_request_irq(&pdev->dev, bbnsm->irq, bbnsm_rtc_irq_handler,
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IRQF_SHARED, "rtc alarm", &pdev->dev);
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if (ret) {
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dev_err(&pdev->dev, "failed to request irq %d: %d\n",
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bbnsm->irq, ret);
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return ret;
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}
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bbnsm->rtc->ops = &bbnsm_rtc_ops;
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bbnsm->rtc->range_max = U32_MAX;
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return devm_rtc_register_device(bbnsm->rtc);
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}
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static const struct of_device_id bbnsm_dt_ids[] = {
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{ .compatible = "nxp,imx93-bbnsm-rtc" },
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{ /* sentinel */ },
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};
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MODULE_DEVICE_TABLE(of, bbnsm_dt_ids);
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static struct platform_driver bbnsm_rtc_driver = {
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.driver = {
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.name = "bbnsm_rtc",
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.of_match_table = bbnsm_dt_ids,
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},
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.probe = bbnsm_rtc_probe,
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};
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module_platform_driver(bbnsm_rtc_driver);
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MODULE_AUTHOR("Jacky Bai <ping.bai@nxp.com>");
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MODULE_DESCRIPTION("NXP BBNSM RTC Driver");
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MODULE_LICENSE("GPL");
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