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path: root/drivers/rtc/rtc-pm8xxx.c
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Diffstat (limited to 'drivers/rtc/rtc-pm8xxx.c')
-rw-r--r--drivers/rtc/rtc-pm8xxx.c553
1 files changed, 553 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
new file mode 100644
index 0000000000..f6b779c12c
--- /dev/null
+++ b/drivers/rtc/rtc-pm8xxx.c
@@ -0,0 +1,553 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * pm8xxx RTC driver
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ * Copyright (c) 2023, Linaro Limited
+ */
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/init.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <asm/unaligned.h>
+
+/* RTC_CTRL register bit fields */
+#define PM8xxx_RTC_ENABLE BIT(7)
+#define PM8xxx_RTC_ALARM_CLEAR BIT(0)
+#define PM8xxx_RTC_ALARM_ENABLE BIT(7)
+
+#define NUM_8_BIT_RTC_REGS 0x4
+
+/**
+ * struct pm8xxx_rtc_regs - describe RTC registers per PMIC versions
+ * @ctrl: address of control register
+ * @write: base address of write registers
+ * @read: base address of read registers
+ * @alarm_ctrl: address of alarm control register
+ * @alarm_ctrl2: address of alarm control2 register
+ * @alarm_rw: base address of alarm read-write registers
+ * @alarm_en: alarm enable mask
+ */
+struct pm8xxx_rtc_regs {
+ unsigned int ctrl;
+ unsigned int write;
+ unsigned int read;
+ unsigned int alarm_ctrl;
+ unsigned int alarm_ctrl2;
+ unsigned int alarm_rw;
+ unsigned int alarm_en;
+};
+
+/**
+ * struct pm8xxx_rtc - RTC driver internal structure
+ * @rtc: RTC device
+ * @regmap: regmap used to access registers
+ * @allow_set_time: whether the time can be set
+ * @alarm_irq: alarm irq number
+ * @regs: register description
+ * @dev: device structure
+ * @nvmem_cell: nvmem cell for offset
+ * @offset: offset from epoch in seconds
+ */
+struct pm8xxx_rtc {
+ struct rtc_device *rtc;
+ struct regmap *regmap;
+ bool allow_set_time;
+ int alarm_irq;
+ const struct pm8xxx_rtc_regs *regs;
+ struct device *dev;
+ struct nvmem_cell *nvmem_cell;
+ u32 offset;
+};
+
+static int pm8xxx_rtc_read_nvmem_offset(struct pm8xxx_rtc *rtc_dd)
+{
+ size_t len;
+ void *buf;
+ int rc;
+
+ buf = nvmem_cell_read(rtc_dd->nvmem_cell, &len);
+ if (IS_ERR(buf)) {
+ rc = PTR_ERR(buf);
+ dev_dbg(rtc_dd->dev, "failed to read nvmem offset: %d\n", rc);
+ return rc;
+ }
+
+ if (len != sizeof(u32)) {
+ dev_dbg(rtc_dd->dev, "unexpected nvmem cell size %zu\n", len);
+ kfree(buf);
+ return -EINVAL;
+ }
+
+ rtc_dd->offset = get_unaligned_le32(buf);
+
+ kfree(buf);
+
+ return 0;
+}
+
+static int pm8xxx_rtc_write_nvmem_offset(struct pm8xxx_rtc *rtc_dd, u32 offset)
+{
+ u8 buf[sizeof(u32)];
+ int rc;
+
+ put_unaligned_le32(offset, buf);
+
+ rc = nvmem_cell_write(rtc_dd->nvmem_cell, buf, sizeof(buf));
+ if (rc < 0) {
+ dev_dbg(rtc_dd->dev, "failed to write nvmem offset: %d\n", rc);
+ return rc;
+ }
+
+ return 0;
+}
+
+static int pm8xxx_rtc_read_offset(struct pm8xxx_rtc *rtc_dd)
+{
+ if (!rtc_dd->nvmem_cell)
+ return 0;
+
+ return pm8xxx_rtc_read_nvmem_offset(rtc_dd);
+}
+
+static int pm8xxx_rtc_read_raw(struct pm8xxx_rtc *rtc_dd, u32 *secs)
+{
+ const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+ u8 value[NUM_8_BIT_RTC_REGS];
+ unsigned int reg;
+ int rc;
+
+ rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value, sizeof(value));
+ if (rc)
+ return rc;
+
+ /*
+ * Read the LSB again and check if there has been a carry over.
+ * If there has, redo the read operation.
+ */
+ rc = regmap_read(rtc_dd->regmap, regs->read, &reg);
+ if (rc < 0)
+ return rc;
+
+ if (reg < value[0]) {
+ rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value,
+ sizeof(value));
+ if (rc)
+ return rc;
+ }
+
+ *secs = get_unaligned_le32(value);
+
+ return 0;
+}
+
+static int pm8xxx_rtc_update_offset(struct pm8xxx_rtc *rtc_dd, u32 secs)
+{
+ u32 raw_secs;
+ u32 offset;
+ int rc;
+
+ if (!rtc_dd->nvmem_cell)
+ return -ENODEV;
+
+ rc = pm8xxx_rtc_read_raw(rtc_dd, &raw_secs);
+ if (rc)
+ return rc;
+
+ offset = secs - raw_secs;
+
+ if (offset == rtc_dd->offset)
+ return 0;
+
+ rc = pm8xxx_rtc_write_nvmem_offset(rtc_dd, offset);
+ if (rc)
+ return rc;
+
+ rtc_dd->offset = offset;
+
+ return 0;
+}
+
+/*
+ * Steps to write the RTC registers.
+ * 1. Disable alarm if enabled.
+ * 2. Disable rtc if enabled.
+ * 3. Write 0x00 to LSB.
+ * 4. Write Byte[1], Byte[2], Byte[3] then Byte[0].
+ * 5. Enable rtc if disabled in step 2.
+ * 6. Enable alarm if disabled in step 1.
+ */
+static int __pm8xxx_rtc_set_time(struct pm8xxx_rtc *rtc_dd, u32 secs)
+{
+ const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+ u8 value[NUM_8_BIT_RTC_REGS];
+ bool alarm_enabled;
+ int rc;
+
+ put_unaligned_le32(secs, value);
+
+ rc = regmap_update_bits_check(rtc_dd->regmap, regs->alarm_ctrl,
+ regs->alarm_en, 0, &alarm_enabled);
+ if (rc)
+ return rc;
+
+ /* Disable RTC */
+ rc = regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE, 0);
+ if (rc)
+ return rc;
+
+ /* Write 0 to Byte[0] */
+ rc = regmap_write(rtc_dd->regmap, regs->write, 0);
+ if (rc)
+ return rc;
+
+ /* Write Byte[1], Byte[2], Byte[3] */
+ rc = regmap_bulk_write(rtc_dd->regmap, regs->write + 1,
+ &value[1], sizeof(value) - 1);
+ if (rc)
+ return rc;
+
+ /* Write Byte[0] */
+ rc = regmap_write(rtc_dd->regmap, regs->write, value[0]);
+ if (rc)
+ return rc;
+
+ /* Enable RTC */
+ rc = regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE,
+ PM8xxx_RTC_ENABLE);
+ if (rc)
+ return rc;
+
+ if (alarm_enabled) {
+ rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
+ regs->alarm_en, regs->alarm_en);
+ if (rc)
+ return rc;
+ }
+
+ return 0;
+}
+
+static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+ u32 secs;
+ int rc;
+
+ secs = rtc_tm_to_time64(tm);
+
+ if (rtc_dd->allow_set_time)
+ rc = __pm8xxx_rtc_set_time(rtc_dd, secs);
+ else
+ rc = pm8xxx_rtc_update_offset(rtc_dd, secs);
+
+ if (rc)
+ return rc;
+
+ dev_dbg(dev, "set time: %ptRd %ptRt (%u + %u)\n", tm, tm,
+ secs - rtc_dd->offset, rtc_dd->offset);
+ return 0;
+}
+
+static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+ u32 secs;
+ int rc;
+
+ rc = pm8xxx_rtc_read_raw(rtc_dd, &secs);
+ if (rc)
+ return rc;
+
+ secs += rtc_dd->offset;
+ rtc_time64_to_tm(secs, tm);
+
+ dev_dbg(dev, "read time: %ptRd %ptRt (%u + %u)\n", tm, tm,
+ secs - rtc_dd->offset, rtc_dd->offset);
+ return 0;
+}
+
+static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+ const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+ u8 value[NUM_8_BIT_RTC_REGS];
+ u32 secs;
+ int rc;
+
+ secs = rtc_tm_to_time64(&alarm->time);
+ secs -= rtc_dd->offset;
+ put_unaligned_le32(secs, value);
+
+ rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
+ regs->alarm_en, 0);
+ if (rc)
+ return rc;
+
+ rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value,
+ sizeof(value));
+ if (rc)
+ return rc;
+
+ if (alarm->enabled) {
+ rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
+ regs->alarm_en, regs->alarm_en);
+ if (rc)
+ return rc;
+ }
+
+ dev_dbg(dev, "set alarm: %ptRd %ptRt\n", &alarm->time, &alarm->time);
+
+ return 0;
+}
+
+static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+ const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+ u8 value[NUM_8_BIT_RTC_REGS];
+ unsigned int ctrl_reg;
+ u32 secs;
+ int rc;
+
+ rc = regmap_bulk_read(rtc_dd->regmap, regs->alarm_rw, value,
+ sizeof(value));
+ if (rc)
+ return rc;
+
+ secs = get_unaligned_le32(value);
+ secs += rtc_dd->offset;
+ rtc_time64_to_tm(secs, &alarm->time);
+
+ rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
+ if (rc)
+ return rc;
+
+ alarm->enabled = !!(ctrl_reg & PM8xxx_RTC_ALARM_ENABLE);
+
+ dev_dbg(dev, "read alarm: %ptRd %ptRt\n", &alarm->time, &alarm->time);
+
+ return 0;
+}
+
+static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
+{
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+ const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+ u8 value[NUM_8_BIT_RTC_REGS] = {0};
+ unsigned int val;
+ int rc;
+
+ if (enable)
+ val = regs->alarm_en;
+ else
+ val = 0;
+
+ rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
+ regs->alarm_en, val);
+ if (rc)
+ return rc;
+
+ /* Clear alarm register */
+ if (!enable) {
+ rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value,
+ sizeof(value));
+ if (rc)
+ return rc;
+ }
+
+ return 0;
+}
+
+static const struct rtc_class_ops pm8xxx_rtc_ops = {
+ .read_time = pm8xxx_rtc_read_time,
+ .set_time = pm8xxx_rtc_set_time,
+ .set_alarm = pm8xxx_rtc_set_alarm,
+ .read_alarm = pm8xxx_rtc_read_alarm,
+ .alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
+{
+ struct pm8xxx_rtc *rtc_dd = dev_id;
+ const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+ int rc;
+
+ rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
+
+ /* Disable alarm */
+ rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
+ regs->alarm_en, 0);
+ if (rc)
+ return IRQ_NONE;
+
+ /* Clear alarm status */
+ rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl2,
+ PM8xxx_RTC_ALARM_CLEAR, 0);
+ if (rc)
+ return IRQ_NONE;
+
+ return IRQ_HANDLED;
+}
+
+static int pm8xxx_rtc_enable(struct pm8xxx_rtc *rtc_dd)
+{
+ const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+
+ return regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE,
+ PM8xxx_RTC_ENABLE);
+}
+
+static const struct pm8xxx_rtc_regs pm8921_regs = {
+ .ctrl = 0x11d,
+ .write = 0x11f,
+ .read = 0x123,
+ .alarm_rw = 0x127,
+ .alarm_ctrl = 0x11d,
+ .alarm_ctrl2 = 0x11e,
+ .alarm_en = BIT(1),
+};
+
+static const struct pm8xxx_rtc_regs pm8058_regs = {
+ .ctrl = 0x1e8,
+ .write = 0x1ea,
+ .read = 0x1ee,
+ .alarm_rw = 0x1f2,
+ .alarm_ctrl = 0x1e8,
+ .alarm_ctrl2 = 0x1e9,
+ .alarm_en = BIT(1),
+};
+
+static const struct pm8xxx_rtc_regs pm8941_regs = {
+ .ctrl = 0x6046,
+ .write = 0x6040,
+ .read = 0x6048,
+ .alarm_rw = 0x6140,
+ .alarm_ctrl = 0x6146,
+ .alarm_ctrl2 = 0x6148,
+ .alarm_en = BIT(7),
+};
+
+static const struct pm8xxx_rtc_regs pmk8350_regs = {
+ .ctrl = 0x6146,
+ .write = 0x6140,
+ .read = 0x6148,
+ .alarm_rw = 0x6240,
+ .alarm_ctrl = 0x6246,
+ .alarm_ctrl2 = 0x6248,
+ .alarm_en = BIT(7),
+};
+
+static const struct of_device_id pm8xxx_id_table[] = {
+ { .compatible = "qcom,pm8921-rtc", .data = &pm8921_regs },
+ { .compatible = "qcom,pm8058-rtc", .data = &pm8058_regs },
+ { .compatible = "qcom,pm8941-rtc", .data = &pm8941_regs },
+ { .compatible = "qcom,pmk8350-rtc", .data = &pmk8350_regs },
+ { },
+};
+MODULE_DEVICE_TABLE(of, pm8xxx_id_table);
+
+static int pm8xxx_rtc_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *match;
+ struct pm8xxx_rtc *rtc_dd;
+ int rc;
+
+ match = of_match_node(pm8xxx_id_table, pdev->dev.of_node);
+ if (!match)
+ return -ENXIO;
+
+ rtc_dd = devm_kzalloc(&pdev->dev, sizeof(*rtc_dd), GFP_KERNEL);
+ if (rtc_dd == NULL)
+ return -ENOMEM;
+
+ rtc_dd->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!rtc_dd->regmap)
+ return -ENXIO;
+
+ rtc_dd->alarm_irq = platform_get_irq(pdev, 0);
+ if (rtc_dd->alarm_irq < 0)
+ return -ENXIO;
+
+ rtc_dd->allow_set_time = of_property_read_bool(pdev->dev.of_node,
+ "allow-set-time");
+
+ rtc_dd->nvmem_cell = devm_nvmem_cell_get(&pdev->dev, "offset");
+ if (IS_ERR(rtc_dd->nvmem_cell)) {
+ rc = PTR_ERR(rtc_dd->nvmem_cell);
+ if (rc != -ENOENT)
+ return rc;
+ rtc_dd->nvmem_cell = NULL;
+ }
+
+ rtc_dd->regs = match->data;
+ rtc_dd->dev = &pdev->dev;
+
+ if (!rtc_dd->allow_set_time) {
+ rc = pm8xxx_rtc_read_offset(rtc_dd);
+ if (rc)
+ return rc;
+ }
+
+ rc = pm8xxx_rtc_enable(rtc_dd);
+ if (rc)
+ return rc;
+
+ platform_set_drvdata(pdev, rtc_dd);
+
+ device_init_wakeup(&pdev->dev, 1);
+
+ rtc_dd->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(rtc_dd->rtc))
+ return PTR_ERR(rtc_dd->rtc);
+
+ rtc_dd->rtc->ops = &pm8xxx_rtc_ops;
+ rtc_dd->rtc->range_max = U32_MAX;
+
+ rc = devm_request_any_context_irq(&pdev->dev, rtc_dd->alarm_irq,
+ pm8xxx_alarm_trigger,
+ IRQF_TRIGGER_RISING,
+ "pm8xxx_rtc_alarm", rtc_dd);
+ if (rc < 0)
+ return rc;
+
+ rc = devm_rtc_register_device(rtc_dd->rtc);
+ if (rc)
+ return rc;
+
+ rc = dev_pm_set_wake_irq(&pdev->dev, rtc_dd->alarm_irq);
+ if (rc)
+ return rc;
+
+ return 0;
+}
+
+static void pm8xxx_remove(struct platform_device *pdev)
+{
+ dev_pm_clear_wake_irq(&pdev->dev);
+}
+
+static struct platform_driver pm8xxx_rtc_driver = {
+ .probe = pm8xxx_rtc_probe,
+ .remove_new = pm8xxx_remove,
+ .driver = {
+ .name = "rtc-pm8xxx",
+ .of_match_table = pm8xxx_id_table,
+ },
+};
+
+module_platform_driver(pm8xxx_rtc_driver);
+
+MODULE_ALIAS("platform:rtc-pm8xxx");
+MODULE_DESCRIPTION("PMIC8xxx RTC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>");
+MODULE_AUTHOR("Johan Hovold <johan@kernel.org>");