--- /dev/null
+// SPDX-License-Identifier: (GPL-2.0-only OR MIT)
+/*
+ * Copyright (C) 2024 Amlogic, Inc. All rights reserved
+ * Author: Yiting Deng <yiting.deng@amlogic.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/time64.h>
+
+/* rtc oscillator rate */
+#define OSC_32K 32768
+#define OSC_24M 24000000
+
+#define RTC_CTRL (0x0 << 2) /* Control RTC */
+#define RTC_ALRM0_EN BIT(0)
+#define RTC_OSC_SEL BIT(8)
+#define RTC_ENABLE BIT(12)
+
+#define RTC_COUNTER_REG (0x1 << 2) /* Program RTC counter initial value */
+
+#define RTC_ALARM0_REG (0x2 << 2) /* Program RTC alarm0 value */
+
+#define RTC_SEC_ADJUST_REG (0x6 << 2) /* Control second-based timing adjustment */
+#define RTC_MATCH_COUNTER GENMASK(18, 0)
+#define RTC_SEC_ADJUST_CTRL GENMASK(20, 19)
+#define RTC_ADJ_VALID BIT(23)
+
+#define RTC_INT_MASK (0x8 << 2) /* RTC interrupt mask */
+#define RTC_ALRM0_IRQ_MSK BIT(0)
+
+#define RTC_INT_CLR (0x9 << 2) /* Clear RTC interrupt */
+#define RTC_ALRM0_IRQ_CLR BIT(0)
+
+#define RTC_OSCIN_CTRL0 (0xa << 2) /* Control RTC clk from 24M */
+#define RTC_OSCIN_CTRL1 (0xb << 2) /* Control RTC clk from 24M */
+#define RTC_OSCIN_IN_EN BIT(31)
+#define RTC_OSCIN_OUT_CFG GENMASK(29, 28)
+#define RTC_OSCIN_OUT_N0M0 GENMASK(11, 0)
+#define RTC_OSCIN_OUT_N1M1 GENMASK(23, 12)
+
+#define RTC_INT_STATUS (0xc << 2) /* RTC interrupt status */
+#define RTC_ALRM0_IRQ_STATUS BIT(0)
+
+#define RTC_REAL_TIME (0xd << 2) /* RTC time value */
+
+#define RTC_OSCIN_OUT_32K_N0 0x2dc
+#define RTC_OSCIN_OUT_32K_N1 0x2db
+#define RTC_OSCIN_OUT_32K_M0 0x1
+#define RTC_OSCIN_OUT_32K_M1 0x2
+
+#define RTC_SWALLOW_SECOND 0x2
+#define RTC_INSERT_SECOND 0x3
+
+struct aml_rtc_config {
+ bool gray_stored;
+};
+
+struct aml_rtc_data {
+ struct regmap *map;
+ struct rtc_device *rtc_dev;
+ int irq;
+ struct clk *rtc_clk;
+ struct clk *sys_clk;
+ int rtc_enabled;
+ const struct aml_rtc_config *config;
+};
+
+static const struct regmap_config aml_rtc_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .max_register = RTC_REAL_TIME,
+};
+
+static inline u32 gray_to_binary(u32 gray)
+{
+ u32 bcd = gray;
+ int size = sizeof(bcd) * 8;
+ int i;
+
+ for (i = 0; (1 << i) < size; i++)
+ bcd ^= bcd >> (1 << i);
+
+ return bcd;
+}
+
+static inline u32 binary_to_gray(u32 bcd)
+{
+ return bcd ^ (bcd >> 1);
+}
+
+static int aml_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+ u32 time_sec;
+
+ /* if RTC disabled, read time failed */
+ if (!rtc->rtc_enabled) {
+ dev_err(dev, "RTC disabled, read time failed\n");
+ return -EINVAL;
+ }
+
+ regmap_read(rtc->map, RTC_REAL_TIME, &time_sec);
+ if (rtc->config->gray_stored)
+ time_sec = gray_to_binary(time_sec);
+ rtc_time64_to_tm(time_sec, tm);
+ dev_dbg(dev, "%s: read time = %us\n", __func__, time_sec);
+
+ return 0;
+}
+
+static int aml_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+ u32 time_sec;
+
+ /* if RTC disabled, first enable it */
+ if (!rtc->rtc_enabled) {
+ regmap_write_bits(rtc->map, RTC_CTRL, RTC_ENABLE, RTC_ENABLE);
+ usleep_range(100, 200);
+ rtc->rtc_enabled = regmap_test_bits(rtc->map, RTC_CTRL, RTC_ENABLE);
+ if (!rtc->rtc_enabled)
+ return -EINVAL;
+ }
+
+ time_sec = rtc_tm_to_time64(tm);
+ if (rtc->config->gray_stored)
+ time_sec = binary_to_gray(time_sec);
+ regmap_write(rtc->map, RTC_COUNTER_REG, time_sec);
+ dev_dbg(dev, "%s: set time = %us\n", __func__, time_sec);
+
+ return 0;
+}
+
+static int aml_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+ time64_t alarm_sec;
+
+ /* if RTC disabled, set alarm failed */
+ if (!rtc->rtc_enabled) {
+ dev_err(dev, "RTC disabled, set alarm failed\n");
+ return -EINVAL;
+ }
+
+ regmap_update_bits(rtc->map, RTC_CTRL,
+ RTC_ALRM0_EN, RTC_ALRM0_EN);
+ regmap_update_bits(rtc->map, RTC_INT_MASK,
+ RTC_ALRM0_IRQ_MSK, 0);
+
+ alarm_sec = rtc_tm_to_time64(&alarm->time);
+ if (rtc->config->gray_stored)
+ alarm_sec = binary_to_gray(alarm_sec);
+ regmap_write(rtc->map, RTC_ALARM0_REG, alarm_sec);
+
+ dev_dbg(dev, "%s: alarm->enabled=%d alarm_set=%llds\n", __func__,
+ alarm->enabled, alarm_sec);
+
+ return 0;
+}
+
+static int aml_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+ u32 alarm_sec;
+ int alarm_enable;
+ int alarm_mask;
+
+ /* if RTC disabled, read alarm failed */
+ if (!rtc->rtc_enabled) {
+ dev_err(dev, "RTC disabled, read alarm failed\n");
+ return -EINVAL;
+ }
+
+ regmap_read(rtc->map, RTC_ALARM0_REG, &alarm_sec);
+ if (rtc->config->gray_stored)
+ alarm_sec = gray_to_binary(alarm_sec);
+ rtc_time64_to_tm(alarm_sec, &alarm->time);
+
+ alarm_enable = regmap_test_bits(rtc->map, RTC_CTRL, RTC_ALRM0_EN);
+ alarm_mask = regmap_test_bits(rtc->map, RTC_INT_MASK, RTC_ALRM0_IRQ_MSK);
+ alarm->enabled = (alarm_enable && !alarm_mask) ? 1 : 0;
+ dev_dbg(dev, "%s: alarm->enabled=%d alarm=%us\n", __func__,
+ alarm->enabled, alarm_sec);
+
+ return 0;
+}
+
+static int aml_rtc_read_offset(struct device *dev, long *offset)
+{
+ struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+ u32 reg_val;
+ long val;
+ int sign, match_counter, enable;
+
+ /* if RTC disabled, read offset failed */
+ if (!rtc->rtc_enabled) {
+ dev_err(dev, "RTC disabled, read offset failed\n");
+ return -EINVAL;
+ }
+
+ regmap_read(rtc->map, RTC_SEC_ADJUST_REG, ®_val);
+ enable = FIELD_GET(RTC_ADJ_VALID, reg_val);
+ if (!enable) {
+ val = 0;
+ } else {
+ sign = FIELD_GET(RTC_SEC_ADJUST_CTRL, reg_val);
+ match_counter = FIELD_GET(RTC_MATCH_COUNTER, reg_val);
+ val = 1000000000 / (match_counter + 1);
+ if (sign == RTC_SWALLOW_SECOND)
+ val = -val;
+ }
+ *offset = val;
+
+ return 0;
+}
+
+static int aml_rtc_set_offset(struct device *dev, long offset)
+{
+ struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+ int sign = 0;
+ int match_counter = 0;
+ int enable = 0;
+ u32 reg_val;
+
+ /* if RTC disabled, set offset failed */
+ if (!rtc->rtc_enabled) {
+ dev_err(dev, "RTC disabled, set offset failed\n");
+ return -EINVAL;
+ }
+
+ if (offset) {
+ enable = 1;
+ sign = offset < 0 ? RTC_SWALLOW_SECOND : RTC_INSERT_SECOND;
+ match_counter = 1000000000 / abs(offset) - 1;
+ if (match_counter < 0 || match_counter > RTC_MATCH_COUNTER)
+ return -EINVAL;
+ }
+
+ reg_val = FIELD_PREP(RTC_ADJ_VALID, enable) |
+ FIELD_PREP(RTC_SEC_ADJUST_CTRL, sign) |
+ FIELD_PREP(RTC_MATCH_COUNTER, match_counter);
+ regmap_write(rtc->map, RTC_SEC_ADJUST_REG, reg_val);
+
+ return 0;
+}
+
+static int aml_rtc_alarm_enable(struct device *dev, unsigned int enabled)
+{
+ struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+
+ if (enabled) {
+ regmap_update_bits(rtc->map, RTC_CTRL,
+ RTC_ALRM0_EN, RTC_ALRM0_EN);
+ regmap_update_bits(rtc->map, RTC_INT_MASK,
+ RTC_ALRM0_IRQ_MSK, 0);
+ } else {
+ regmap_update_bits(rtc->map, RTC_INT_MASK,
+ RTC_ALRM0_IRQ_MSK, RTC_ALRM0_IRQ_MSK);
+ regmap_update_bits(rtc->map, RTC_CTRL,
+ RTC_ALRM0_EN, 0);
+ }
+
+ return 0;
+}
+
+static const struct rtc_class_ops aml_rtc_ops = {
+ .read_time = aml_rtc_read_time,
+ .set_time = aml_rtc_set_time,
+ .read_alarm = aml_rtc_read_alarm,
+ .set_alarm = aml_rtc_set_alarm,
+ .alarm_irq_enable = aml_rtc_alarm_enable,
+ .read_offset = aml_rtc_read_offset,
+ .set_offset = aml_rtc_set_offset,
+};
+
+static irqreturn_t aml_rtc_handler(int irq, void *data)
+{
+ struct aml_rtc_data *rtc = (struct aml_rtc_data *)data;
+
+ regmap_write(rtc->map, RTC_ALARM0_REG, 0);
+ regmap_write(rtc->map, RTC_INT_CLR, RTC_ALRM0_IRQ_STATUS);
+
+ rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
+
+ return IRQ_HANDLED;
+}
+
+static void aml_rtc_init(struct aml_rtc_data *rtc)
+{
+ u32 reg_val = 0;
+
+ rtc->rtc_enabled = regmap_test_bits(rtc->map, RTC_CTRL, RTC_ENABLE);
+ if (!rtc->rtc_enabled) {
+ if (clk_get_rate(rtc->rtc_clk) == OSC_24M) {
+ /* select 24M oscillator */
+ regmap_write_bits(rtc->map, RTC_CTRL, RTC_OSC_SEL, RTC_OSC_SEL);
+
+ /*
+ * Set RTC oscillator to freq_out to freq_in/((N0*M0+N1*M1)/(M0+M1))
+ * Enable clock_in gate of oscillator 24MHz
+ * Set N0 to 733, N1 to 732
+ */
+ reg_val = FIELD_PREP(RTC_OSCIN_IN_EN, 1)
+ | FIELD_PREP(RTC_OSCIN_OUT_CFG, 1)
+ | FIELD_PREP(RTC_OSCIN_OUT_N0M0, RTC_OSCIN_OUT_32K_N0)
+ | FIELD_PREP(RTC_OSCIN_OUT_N1M1, RTC_OSCIN_OUT_32K_N1);
+ regmap_write_bits(rtc->map, RTC_OSCIN_CTRL0, RTC_OSCIN_IN_EN
+ | RTC_OSCIN_OUT_CFG | RTC_OSCIN_OUT_N0M0
+ | RTC_OSCIN_OUT_N1M1, reg_val);
+
+ /* Set M0 to 2, M1 to 3, so freq_out = 32768 Hz*/
+ reg_val = FIELD_PREP(RTC_OSCIN_OUT_N0M0, RTC_OSCIN_OUT_32K_M0)
+ | FIELD_PREP(RTC_OSCIN_OUT_N1M1, RTC_OSCIN_OUT_32K_M1);
+ regmap_write_bits(rtc->map, RTC_OSCIN_CTRL1, RTC_OSCIN_OUT_N0M0
+ | RTC_OSCIN_OUT_N1M1, reg_val);
+ } else {
+ /* select 32K oscillator */
+ regmap_write_bits(rtc->map, RTC_CTRL, RTC_OSC_SEL, 0);
+ }
+ }
+ regmap_write_bits(rtc->map, RTC_INT_MASK,
+ RTC_ALRM0_IRQ_MSK, RTC_ALRM0_IRQ_MSK);
+ regmap_write_bits(rtc->map, RTC_CTRL, RTC_ALRM0_EN, 0);
+}
+
+static int aml_rtc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct aml_rtc_data *rtc;
+ void __iomem *base;
+ int ret = 0;
+
+ rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL);
+ if (!rtc)
+ return -ENOMEM;
+
+ rtc->config = of_device_get_match_data(dev);
+ if (!rtc->config)
+ return -ENODEV;
+
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return dev_err_probe(dev, PTR_ERR(base), "resource ioremap failed\n");
+
+ rtc->map = devm_regmap_init_mmio(dev, base, &aml_rtc_regmap_config);
+ if (IS_ERR(rtc->map))
+ return dev_err_probe(dev, PTR_ERR(rtc->map), "regmap init failed\n");
+
+ rtc->irq = platform_get_irq(pdev, 0);
+ if (rtc->irq < 0)
+ return rtc->irq;
+
+ rtc->rtc_clk = devm_clk_get(dev, "osc");
+ if (IS_ERR(rtc->rtc_clk))
+ return dev_err_probe(dev, PTR_ERR(rtc->rtc_clk),
+ "failed to find rtc clock\n");
+ if (clk_get_rate(rtc->rtc_clk) != OSC_32K && clk_get_rate(rtc->rtc_clk) != OSC_24M)
+ return dev_err_probe(dev, -EINVAL, "Invalid clock configuration\n");
+
+ rtc->sys_clk = devm_clk_get_enabled(dev, "sys");
+ if (IS_ERR(rtc->sys_clk))
+ return dev_err_probe(dev, PTR_ERR(rtc->sys_clk),
+ "failed to get_enable rtc sys clk\n");
+ aml_rtc_init(rtc);
+
+ device_init_wakeup(dev, 1);
+ platform_set_drvdata(pdev, rtc);
+
+ rtc->rtc_dev = devm_rtc_allocate_device(dev);
+ if (IS_ERR(rtc->rtc_dev)) {
+ ret = PTR_ERR(rtc->rtc_dev);
+ goto err_clk;
+ }
+
+ ret = devm_request_irq(dev, rtc->irq, aml_rtc_handler,
+ IRQF_ONESHOT, "aml-rtc alarm", rtc);
+ if (ret) {
+ dev_err_probe(dev, ret, "IRQ%d request failed, ret = %d\n",
+ rtc->irq, ret);
+ goto err_clk;
+ }
+
+ rtc->rtc_dev->ops = &aml_rtc_ops;
+ rtc->rtc_dev->range_min = 0;
+ rtc->rtc_dev->range_max = U32_MAX;
+
+ ret = devm_rtc_register_device(rtc->rtc_dev);
+ if (ret) {
+ dev_err_probe(&pdev->dev, ret, "Failed to register RTC device: %d\n", ret);
+ goto err_clk;
+ }
+
+ return 0;
+err_clk:
+ clk_disable_unprepare(rtc->sys_clk);
+ device_init_wakeup(dev, 0);
+
+ return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int aml_rtc_suspend(struct device *dev)
+{
+ struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev))
+ enable_irq_wake(rtc->irq);
+
+ return 0;
+}
+
+static int aml_rtc_resume(struct device *dev)
+{
+ struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev))
+ disable_irq_wake(rtc->irq);
+
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(aml_rtc_pm_ops,
+ aml_rtc_suspend, aml_rtc_resume);
+
+static void aml_rtc_remove(struct platform_device *pdev)
+{
+ struct aml_rtc_data *rtc = dev_get_drvdata(&pdev->dev);
+
+ clk_disable_unprepare(rtc->sys_clk);
+ device_init_wakeup(&pdev->dev, 0);
+}
+
+static const struct aml_rtc_config a5_rtc_config = {
+};
+
+static const struct aml_rtc_config a4_rtc_config = {
+ .gray_stored = true,
+};
+
+static const struct of_device_id aml_rtc_device_id[] = {
+ {
+ .compatible = "amlogic,a4-rtc",
+ .data = &a4_rtc_config,
+ },
+ {
+ .compatible = "amlogic,a5-rtc",
+ .data = &a5_rtc_config,
+ },
+};
+MODULE_DEVICE_TABLE(of, aml_rtc_device_id);
+
+static struct platform_driver aml_rtc_driver = {
+ .probe = aml_rtc_probe,
+ .remove = aml_rtc_remove,
+ .driver = {
+ .name = "aml-rtc",
+ .pm = &aml_rtc_pm_ops,
+ .of_match_table = aml_rtc_device_id,
+ },
+};
+
+module_platform_driver(aml_rtc_driver);
+MODULE_DESCRIPTION("Amlogic RTC driver");
+MODULE_AUTHOR("Yiting Deng <yiting.deng@amlogic.com>");
+MODULE_LICENSE("GPL");
projects / thirdparty / kernel / linux.git / commitdiff
