v4.19.13 snapshot.
diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
new file mode 100644
index 0000000..b2483a7
--- /dev/null
+++ b/drivers/rtc/rtc-snvs.c
@@ -0,0 +1,429 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Copyright (C) 2011-2012 Freescale Semiconductor, Inc.
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/clk.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#define SNVS_LPREGISTER_OFFSET 0x34
+
+/* These register offsets are relative to LP (Low Power) range */
+#define SNVS_LPCR 0x04
+#define SNVS_LPSR 0x18
+#define SNVS_LPSRTCMR 0x1c
+#define SNVS_LPSRTCLR 0x20
+#define SNVS_LPTAR 0x24
+#define SNVS_LPPGDR 0x30
+
+#define SNVS_LPCR_SRTC_ENV (1 << 0)
+#define SNVS_LPCR_LPTA_EN (1 << 1)
+#define SNVS_LPCR_LPWUI_EN (1 << 3)
+#define SNVS_LPSR_LPTA (1 << 0)
+
+#define SNVS_LPPGDR_INIT 0x41736166
+#define CNTR_TO_SECS_SH 15
+
+struct snvs_rtc_data {
+ struct rtc_device *rtc;
+ struct regmap *regmap;
+ int offset;
+ int irq;
+ struct clk *clk;
+};
+
+/* Read 64 bit timer register, which could be in inconsistent state */
+static u64 rtc_read_lpsrt(struct snvs_rtc_data *data)
+{
+ u32 msb, lsb;
+
+ regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &msb);
+ regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &lsb);
+ return (u64)msb << 32 | lsb;
+}
+
+/* Read the secure real time counter, taking care to deal with the cases of the
+ * counter updating while being read.
+ */
+static u32 rtc_read_lp_counter(struct snvs_rtc_data *data)
+{
+ u64 read1, read2;
+ unsigned int timeout = 100;
+
+ /* As expected, the registers might update between the read of the LSB
+ * reg and the MSB reg. It's also possible that one register might be
+ * in partially modified state as well.
+ */
+ read1 = rtc_read_lpsrt(data);
+ do {
+ read2 = read1;
+ read1 = rtc_read_lpsrt(data);
+ } while (read1 != read2 && --timeout);
+ if (!timeout)
+ dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
+
+ /* Convert 47-bit counter to 32-bit raw second count */
+ return (u32) (read1 >> CNTR_TO_SECS_SH);
+}
+
+/* Just read the lsb from the counter, dealing with inconsistent state */
+static int rtc_read_lp_counter_lsb(struct snvs_rtc_data *data, u32 *lsb)
+{
+ u32 count1, count2;
+ unsigned int timeout = 100;
+
+ regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
+ do {
+ count2 = count1;
+ regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
+ } while (count1 != count2 && --timeout);
+ if (!timeout) {
+ dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
+ return -ETIMEDOUT;
+ }
+
+ *lsb = count1;
+ return 0;
+}
+
+static int rtc_write_sync_lp(struct snvs_rtc_data *data)
+{
+ u32 count1, count2;
+ u32 elapsed;
+ unsigned int timeout = 1000;
+ int ret;
+
+ ret = rtc_read_lp_counter_lsb(data, &count1);
+ if (ret)
+ return ret;
+
+ /* Wait for 3 CKIL cycles, about 61.0-91.5 µs */
+ do {
+ ret = rtc_read_lp_counter_lsb(data, &count2);
+ if (ret)
+ return ret;
+ elapsed = count2 - count1; /* wrap around _is_ handled! */
+ } while (elapsed < 3 && --timeout);
+ if (!timeout) {
+ dev_err(&data->rtc->dev, "Timeout waiting for LPSRT Counter to change\n");
+ return -ETIMEDOUT;
+ }
+ return 0;
+}
+
+static int snvs_rtc_enable(struct snvs_rtc_data *data, bool enable)
+{
+ int timeout = 1000;
+ u32 lpcr;
+
+ regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_SRTC_ENV,
+ enable ? SNVS_LPCR_SRTC_ENV : 0);
+
+ while (--timeout) {
+ regmap_read(data->regmap, data->offset + SNVS_LPCR, &lpcr);
+
+ if (enable) {
+ if (lpcr & SNVS_LPCR_SRTC_ENV)
+ break;
+ } else {
+ if (!(lpcr & SNVS_LPCR_SRTC_ENV))
+ break;
+ }
+ }
+
+ if (!timeout)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static int snvs_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct snvs_rtc_data *data = dev_get_drvdata(dev);
+ unsigned long time = rtc_read_lp_counter(data);
+
+ rtc_time_to_tm(time, tm);
+
+ return 0;
+}
+
+static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct snvs_rtc_data *data = dev_get_drvdata(dev);
+ unsigned long time;
+ int ret;
+
+ rtc_tm_to_time(tm, &time);
+
+ /* Disable RTC first */
+ ret = snvs_rtc_enable(data, false);
+ if (ret)
+ return ret;
+
+ /* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */
+ regmap_write(data->regmap, data->offset + SNVS_LPSRTCLR, time << CNTR_TO_SECS_SH);
+ regmap_write(data->regmap, data->offset + SNVS_LPSRTCMR, time >> (32 - CNTR_TO_SECS_SH));
+
+ /* Enable RTC again */
+ ret = snvs_rtc_enable(data, true);
+
+ return ret;
+}
+
+static int snvs_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct snvs_rtc_data *data = dev_get_drvdata(dev);
+ u32 lptar, lpsr;
+
+ regmap_read(data->regmap, data->offset + SNVS_LPTAR, &lptar);
+ rtc_time_to_tm(lptar, &alrm->time);
+
+ regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
+ alrm->pending = (lpsr & SNVS_LPSR_LPTA) ? 1 : 0;
+
+ return 0;
+}
+
+static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
+{
+ struct snvs_rtc_data *data = dev_get_drvdata(dev);
+
+ regmap_update_bits(data->regmap, data->offset + SNVS_LPCR,
+ (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN),
+ enable ? (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN) : 0);
+
+ return rtc_write_sync_lp(data);
+}
+
+static int snvs_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct snvs_rtc_data *data = dev_get_drvdata(dev);
+ struct rtc_time *alrm_tm = &alrm->time;
+ unsigned long time;
+ int ret;
+
+ rtc_tm_to_time(alrm_tm, &time);
+
+ regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_LPTA_EN, 0);
+ ret = rtc_write_sync_lp(data);
+ if (ret)
+ return ret;
+ regmap_write(data->regmap, data->offset + SNVS_LPTAR, time);
+
+ /* Clear alarm interrupt status bit */
+ regmap_write(data->regmap, data->offset + SNVS_LPSR, SNVS_LPSR_LPTA);
+
+ return snvs_rtc_alarm_irq_enable(dev, alrm->enabled);
+}
+
+static const struct rtc_class_ops snvs_rtc_ops = {
+ .read_time = snvs_rtc_read_time,
+ .set_time = snvs_rtc_set_time,
+ .read_alarm = snvs_rtc_read_alarm,
+ .set_alarm = snvs_rtc_set_alarm,
+ .alarm_irq_enable = snvs_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
+{
+ struct device *dev = dev_id;
+ struct snvs_rtc_data *data = dev_get_drvdata(dev);
+ u32 lpsr;
+ u32 events = 0;
+
+ regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
+
+ if (lpsr & SNVS_LPSR_LPTA) {
+ events |= (RTC_AF | RTC_IRQF);
+
+ /* RTC alarm should be one-shot */
+ snvs_rtc_alarm_irq_enable(dev, 0);
+
+ rtc_update_irq(data->rtc, 1, events);
+ }
+
+ /* clear interrupt status */
+ regmap_write(data->regmap, data->offset + SNVS_LPSR, lpsr);
+
+ return events ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static const struct regmap_config snvs_rtc_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+};
+
+static int snvs_rtc_probe(struct platform_device *pdev)
+{
+ struct snvs_rtc_data *data;
+ struct resource *res;
+ int ret;
+ void __iomem *mmio;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");
+
+ if (IS_ERR(data->regmap)) {
+ dev_warn(&pdev->dev, "snvs rtc: you use old dts file, please update it\n");
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ mmio = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mmio))
+ return PTR_ERR(mmio);
+
+ data->regmap = devm_regmap_init_mmio(&pdev->dev, mmio, &snvs_rtc_config);
+ } else {
+ data->offset = SNVS_LPREGISTER_OFFSET;
+ of_property_read_u32(pdev->dev.of_node, "offset", &data->offset);
+ }
+
+ if (IS_ERR(data->regmap)) {
+ dev_err(&pdev->dev, "Can't find snvs syscon\n");
+ return -ENODEV;
+ }
+
+ data->irq = platform_get_irq(pdev, 0);
+ if (data->irq < 0)
+ return data->irq;
+
+ data->clk = devm_clk_get(&pdev->dev, "snvs-rtc");
+ if (IS_ERR(data->clk)) {
+ data->clk = NULL;
+ } else {
+ ret = clk_prepare_enable(data->clk);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Could not prepare or enable the snvs clock\n");
+ return ret;
+ }
+ }
+
+ platform_set_drvdata(pdev, data);
+
+ /* Initialize glitch detect */
+ regmap_write(data->regmap, data->offset + SNVS_LPPGDR, SNVS_LPPGDR_INIT);
+
+ /* Clear interrupt status */
+ regmap_write(data->regmap, data->offset + SNVS_LPSR, 0xffffffff);
+
+ /* Enable RTC */
+ ret = snvs_rtc_enable(data, true);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to enable rtc %d\n", ret);
+ goto error_rtc_device_register;
+ }
+
+ device_init_wakeup(&pdev->dev, true);
+
+ ret = devm_request_irq(&pdev->dev, data->irq, snvs_rtc_irq_handler,
+ IRQF_SHARED, "rtc alarm", &pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request irq %d: %d\n",
+ data->irq, ret);
+ goto error_rtc_device_register;
+ }
+
+ data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+ &snvs_rtc_ops, THIS_MODULE);
+ if (IS_ERR(data->rtc)) {
+ ret = PTR_ERR(data->rtc);
+ dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
+ goto error_rtc_device_register;
+ }
+
+ return 0;
+
+error_rtc_device_register:
+ if (data->clk)
+ clk_disable_unprepare(data->clk);
+
+ return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int snvs_rtc_suspend(struct device *dev)
+{
+ struct snvs_rtc_data *data = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev))
+ return enable_irq_wake(data->irq);
+
+ return 0;
+}
+
+static int snvs_rtc_suspend_noirq(struct device *dev)
+{
+ struct snvs_rtc_data *data = dev_get_drvdata(dev);
+
+ if (data->clk)
+ clk_disable_unprepare(data->clk);
+
+ return 0;
+}
+
+static int snvs_rtc_resume(struct device *dev)
+{
+ struct snvs_rtc_data *data = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev))
+ return disable_irq_wake(data->irq);
+
+ return 0;
+}
+
+static int snvs_rtc_resume_noirq(struct device *dev)
+{
+ struct snvs_rtc_data *data = dev_get_drvdata(dev);
+
+ if (data->clk)
+ return clk_prepare_enable(data->clk);
+
+ return 0;
+}
+
+static const struct dev_pm_ops snvs_rtc_pm_ops = {
+ .suspend = snvs_rtc_suspend,
+ .suspend_noirq = snvs_rtc_suspend_noirq,
+ .resume = snvs_rtc_resume,
+ .resume_noirq = snvs_rtc_resume_noirq,
+};
+
+#define SNVS_RTC_PM_OPS (&snvs_rtc_pm_ops)
+
+#else
+
+#define SNVS_RTC_PM_OPS NULL
+
+#endif
+
+static const struct of_device_id snvs_dt_ids[] = {
+ { .compatible = "fsl,sec-v4.0-mon-rtc-lp", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, snvs_dt_ids);
+
+static struct platform_driver snvs_rtc_driver = {
+ .driver = {
+ .name = "snvs_rtc",
+ .pm = SNVS_RTC_PM_OPS,
+ .of_match_table = snvs_dt_ids,
+ },
+ .probe = snvs_rtc_probe,
+};
+module_platform_driver(snvs_rtc_driver);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("Freescale SNVS RTC Driver");
+MODULE_LICENSE("GPL");