[PATCH v6 2/3] rtc: sophgo: add rtc support for Sophgo CV1800 SoC
Jingbao Qiu
qiujingbao.dlmu at gmail.com
Mon Jan 15 08:05:59 PST 2024
Implement the RTC driver for CV1800, which able to provide time alarm
and calibrate functionality.
Signed-off-by: Jingbao Qiu <qiujingbao.dlmu at gmail.com>
---
Depends on https://lore.kernel.org/all/IA1PR20MB4953C774D41EDF1EADB6EC18BB6D2@IA1PR20MB4953.namprd20.prod.outlook.com/
---
drivers/rtc/Kconfig | 7 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-cv1800.c | 397 +++++++++++++++++++++++++++++++++++++++
3 files changed, 405 insertions(+)
create mode 100644 drivers/rtc/rtc-cv1800.c
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 1ea9c7600150..3633f45c7fa0 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1115,6 +1115,13 @@ config RTC_DRV_DS2404
This driver can also be built as a module. If so, the module
will be called rtc-ds2404.
+config RTC_DRV_CV1800
+ tristate "Sophgo CV1800 RTC"
+ depends on ARCH_SOPHGO || COMPILE_TEST
+ help
+ If you say Y here you will get support for the RTC found on
+ CV1800
+
config RTC_DRV_DA9052
tristate "Dialog DA9052/DA9053 RTC"
depends on PMIC_DA9052
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 31c4606fd9bf..a5fc78ac0094 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_RTC_DRV_CADENCE) += rtc-cadence.o
obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o
obj-$(CONFIG_RTC_DRV_CPCAP) += rtc-cpcap.o
obj-$(CONFIG_RTC_DRV_CROS_EC) += rtc-cros-ec.o
+obj-$(CONFIG_RTC_DRV_CV1800) += rtc-cv1800.o
obj-$(CONFIG_RTC_DRV_DA9052) += rtc-da9052.o
obj-$(CONFIG_RTC_DRV_DA9055) += rtc-da9055.o
obj-$(CONFIG_RTC_DRV_DA9063) += rtc-da9063.o
diff --git a/drivers/rtc/rtc-cv1800.c b/drivers/rtc/rtc-cv1800.c
new file mode 100644
index 000000000000..836f15a881e0
--- /dev/null
+++ b/drivers/rtc/rtc-cv1800.c
@@ -0,0 +1,397 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * rtc-cv1800.c: RTC driver for Sophgo cv1800 RTC
+ *
+ * Author: Jingbao Qiu <qiujingbao.dlmu at gmail.com>
+ */
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+
+#define ANA_CALIB 0x1000
+#define SEC_PULSE_GEN 0x1004
+#define ALARM_TIME 0x1008
+#define ALARM_ENABLE 0x100C
+#define SET_SEC_CNTR_VAL 0x1010
+#define SET_SEC_CNTR_TRIG 0x1014
+#define SEC_CNTR_VAL 0x1018
+#define APB_RDATA_SEL 0x103C
+#define POR_DB_MAGIC_KEY 0x1068
+#define EN_PWR_WAKEUP 0x10BC
+
+/*
+ * When in VDDBKUP domain, this MACRO register
+ * does not power down
+ */
+#define MACRO_DA_CLEAR_ALL 0x1480
+#define MACRO_DA_SOC_READY 0x148C
+#define MACRO_RO_T 0x14A8
+#define MACRO_RG_SET_T 0x1498
+#define CTRL 0x08
+#define FC_COARSE_EN 0x40
+#define FC_COARSE_CAL 0x44
+#define FC_FINE_EN 0x48
+#define FC_FINE_CAL 0x50
+#define CTRL_MODE_MASK BIT(10)
+#define CTRL_MODE_OSC32K 0x00UL
+#define CTRL_MODE_XTAL32K BIT(0)
+#define FC_COARSE_CAL_VAL_SHIFT 0
+#define FC_COARSE_CAL_VAL_MASK GENMASK(15, 0)
+#define FC_COARSE_CAL_TIME_SHIFT 16
+#define FC_COARSE_CAL_TIME_MASK GENMASK(31, 16)
+#define FC_FINE_CAL_VAL_SHIFT 0
+#define FC_FINE_CAL_VAL_MASK GENMASK(23, 0)
+#define FC_FINE_CAL_TIME_SHIFT 24
+#define FC_FINE_CAL_TIME_MASK GENMASK(31, 24)
+#define SEC_PULSE_GEN_INT_SHIFT 0
+#define SEC_PULSE_GEN_INT_MASK GENMASK(7, 0)
+#define SEC_PULSE_GEN_FRAC_SHIFT 8
+#define SEC_PULSE_GEN_FRAC_MASK GENMASK(24, 8)
+#define SEC_PULSE_GEN_SEL_SHIFT 31
+#define SEC_PULSE_GEN_SEL_MASK GENMASK(30, 0)
+#define SEC_PULSE_SEL_INNER BIT(31)
+#define CALIB_INIT_VAL (BIT(8) || BIT(16))
+#define CALIB_SEL_FTUNE_MASK GENMASK(30, 0)
+#define CALIB_SEL_FTUNE_INNER 0x00UL
+#define CALIB_OFFSET_INIT 128
+#define CALIB_OFFSET_SHIFT BIT(0)
+#define CALIB_FREQ 256000000000
+#define CALIB_FRAC_EXT 10000
+#define CALIB_FREQ_NS 40
+#define CALIB_FREQ_MULT 256
+#define CALIB_FC_COARSE_PLUS_OFFSET 770
+#define CALIB_FC_COARSE_SUB_OFFSET 755
+#define REG_ENABLE_FUN BIT(0)
+#define REG_DISABLE_FUN 0x00UL
+#define REG_INIT_TIMEOUT 100
+#define SEC_MAX_VAL 0xFFFFFFFF
+#define ALARM_ENABLE_MASK BIT(0)
+#define SET_SEC_CNTR_VAL_INIT (BIT(28) || BIT(29))
+#define DEALY_TIME_PREPARE 400
+#define DEALY_TIME_LOOP 100
+
+struct cv1800_rtc_priv {
+ struct rtc_device *rtc_dev;
+ struct device *dev;
+ struct regmap *rtc_map;
+ struct clk *clk;
+ int irq;
+};
+
+static int cv1800_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+
+ regmap_write(info->rtc_map, ALARM_ENABLE, enabled);
+
+ return 0;
+}
+
+static int cv1800_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+ unsigned long alarm_time;
+
+ alarm_time = rtc_tm_to_time64(&alrm->time);
+
+ cv1800_rtc_alarm_irq_enable(dev, REG_DISABLE_FUN);
+
+ regmap_write(info->rtc_map, ALARM_TIME, alarm_time);
+
+ cv1800_rtc_alarm_irq_enable(dev, alrm->enabled);
+
+ return 0;
+}
+
+static int cv1800_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+ uint32_t enabled;
+ uint32_t time;
+
+ regmap_read(info->rtc_map, ALARM_ENABLE, &enabled);
+
+ alarm->enabled = enabled & ALARM_ENABLE_MASK;
+
+ regmap_read(info->rtc_map, ALARM_TIME, &time);
+
+ rtc_time64_to_tm(time, &alarm->time);
+
+ return 0;
+}
+
+/**
+ * cv1800_rtc_32k_coarse_val_calib() - Using an external
+ * clock to coarse calibrate the crystal oscillator
+ * @info: the device of calibrated
+ *
+ * @return 0 on success, or -1 on fail
+ *
+ * This RTC has an independent 32KHz oscillator. However,
+ * the accuracy of this oscillator is easily affected by
+ * external environmental interference,resulting in lower
+ * accuracy than the internal oscillator.Therefore, a 25M
+ * crystal oscillator is used as a reference source to
+ * calibrate the RTC and improve its accuracy.Calibration
+ * is completed through two steps, namely rough calibration
+ * and fine calibration.
+ */
+static int cv1800_rtc_32k_coarse_val_calib(struct cv1800_rtc_priv *info)
+{
+ uint32_t calib_val = 0;
+ uint32_t coarse_val = 0;
+ uint32_t time_now = 0;
+ uint32_t time_next = 0;
+ uint32_t offset = CALIB_OFFSET_INIT;
+ uint32_t coarse_timeout = REG_INIT_TIMEOUT;
+ uint32_t get_val_timeout = 0;
+
+ regmap_write(info->rtc_map, ANA_CALIB, CALIB_INIT_VAL);
+
+ udelay(DEALY_TIME_PREPARE);
+
+ /* Select 32K OSC tuning val source from rtc_sys */
+ regmap_update_bits(info->rtc_map, SEC_PULSE_GEN,
+ (unsigned int)(~SEC_PULSE_GEN_SEL_MASK),
+ (unsigned int)(~SEC_PULSE_SEL_INNER));
+
+ regmap_read(info->rtc_map, ANA_CALIB, &calib_val);
+
+ regmap_write(info->rtc_map, FC_COARSE_EN, REG_ENABLE_FUN);
+
+ while (--coarse_timeout) {
+ regmap_read(info->rtc_map, FC_COARSE_CAL, &time_now);
+ time_now >>= FC_COARSE_CAL_TIME_SHIFT;
+
+ get_val_timeout = REG_INIT_TIMEOUT;
+
+ while (time_next <= time_now && --get_val_timeout) {
+ regmap_read(info->rtc_map, FC_COARSE_CAL, &time_next);
+ time_next >>= FC_COARSE_CAL_TIME_SHIFT;
+ udelay(DEALY_TIME_LOOP);
+ }
+
+ if (!get_val_timeout)
+ return -1;
+
+ udelay(DEALY_TIME_PREPARE);
+
+ regmap_read(info->rtc_map, FC_COARSE_CAL, &coarse_val);
+ coarse_val &= FC_COARSE_CAL_VAL_MASK;
+
+ if (coarse_val > CALIB_FC_COARSE_PLUS_OFFSET) {
+ calib_val += offset;
+ offset >>= CALIB_OFFSET_SHIFT;
+ regmap_write(info->rtc_map, ANA_CALIB, calib_val);
+ } else if (coarse_val < CALIB_FC_COARSE_SUB_OFFSET) {
+ calib_val -= offset;
+ offset >>= CALIB_OFFSET_SHIFT;
+ regmap_write(info->rtc_map, ANA_CALIB, calib_val);
+ } else {
+ regmap_write(info->rtc_map, FC_COARSE_EN,
+ REG_DISABLE_FUN);
+ break;
+ }
+
+ if (offset == 0)
+ return -1;
+ }
+
+ return 0;
+}
+
+static int cv1800_rtc_32k_fine_val_calib(struct cv1800_rtc_priv *info)
+{
+ uint32_t val;
+ uint64_t freq = CALIB_FREQ;
+ uint32_t sec_cnt;
+ uint32_t timeout = REG_INIT_TIMEOUT;
+ uint32_t time_now = 0;
+ uint32_t time_next = 0;
+
+ regmap_write(info->rtc_map, FC_FINE_EN, REG_ENABLE_FUN);
+
+ regmap_read(info->rtc_map, FC_FINE_CAL, &time_now);
+ time_now >>= FC_FINE_CAL_TIME_SHIFT;
+
+ while (time_next <= time_now && --timeout) {
+ regmap_read(info->rtc_map, FC_FINE_CAL, &time_next);
+ time_next >>= FC_FINE_CAL_TIME_SHIFT;
+ udelay(DEALY_TIME_LOOP);
+ }
+
+ if (!timeout)
+ return -1;
+
+ regmap_read(info->rtc_map, FC_FINE_CAL, &val);
+ val &= FC_FINE_CAL_VAL_MASK;
+
+ do_div(freq, CALIB_FREQ_NS);
+ freq = freq * CALIB_FRAC_EXT;
+ do_div(freq, val);
+
+ sec_cnt = ((do_div(freq, CALIB_FRAC_EXT) * CALIB_FREQ_MULT) /
+ CALIB_FRAC_EXT &
+ SEC_PULSE_GEN_INT_MASK) +
+ (freq << SEC_PULSE_GEN_FRAC_SHIFT);
+
+ regmap_write(info->rtc_map, SEC_PULSE_GEN, sec_cnt);
+ regmap_write(info->rtc_map, FC_FINE_EN, REG_DISABLE_FUN);
+
+ return 0;
+}
+
+static void rtc_enable_sec_counter(struct cv1800_rtc_priv *info)
+{
+ unsigned int sec_ro_t;
+ unsigned int sec;
+
+ /* select inner sec pulse and select reg set calibration val */
+ regmap_update_bits(info->rtc_map, SEC_PULSE_GEN,
+ (unsigned int)(~SEC_PULSE_GEN_SEL_MASK),
+ (unsigned int)(~SEC_PULSE_SEL_INNER));
+
+ regmap_update_bits(info->rtc_map, ANA_CALIB,
+ (unsigned int)(~CALIB_SEL_FTUNE_MASK),
+ CALIB_SEL_FTUNE_INNER);
+
+ sec = SET_SEC_CNTR_VAL_INIT;
+
+ /* load from MACRO register */
+ regmap_read(info->rtc_map, MACRO_RO_T, &sec_ro_t);
+ if (sec_ro_t > (SET_SEC_CNTR_VAL_INIT))
+ sec = sec_ro_t;
+
+ regmap_write(info->rtc_map, SET_SEC_CNTR_VAL, sec);
+ regmap_write(info->rtc_map, SET_SEC_CNTR_TRIG, REG_ENABLE_FUN);
+}
+
+static int cv1800_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+ unsigned int sec;
+
+ regmap_read(info->rtc_map, SEC_CNTR_VAL, &sec);
+
+ rtc_time64_to_tm(sec, tm);
+
+ return 0;
+}
+
+static int cv1800_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+ unsigned long sec;
+
+ sec = rtc_tm_to_time64(tm);
+
+ regmap_write(info->rtc_map, SET_SEC_CNTR_VAL, sec);
+ regmap_write(info->rtc_map, SET_SEC_CNTR_TRIG, REG_ENABLE_FUN);
+
+ regmap_write(info->rtc_map, MACRO_RG_SET_T, sec);
+
+ return 0;
+}
+
+static irqreturn_t cv1800_rtc_irq_handler(int irq, void *dev_id)
+{
+ struct rtc_device *rtc = dev_id;
+
+ rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
+
+ return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops cv800b_rtc_ops = {
+ .read_time = cv1800_rtc_read_time,
+ .set_time = cv1800_rtc_set_time,
+ .read_alarm = cv1800_rtc_read_alarm,
+ .set_alarm = cv1800_rtc_set_alarm,
+ .alarm_irq_enable = cv1800_rtc_alarm_irq_enable,
+};
+
+static int cv1800_rtc_probe(struct platform_device *pdev)
+{
+ struct cv1800_rtc_priv *rtc;
+ uint32_t ctrl_val;
+ int ret;
+
+ rtc = devm_kzalloc(&pdev->dev, sizeof(struct cv1800_rtc_priv),
+ GFP_KERNEL);
+ if (!rtc)
+ return -ENOMEM;
+
+ rtc->dev = &pdev->dev;
+
+ rtc->rtc_map = syscon_node_to_regmap(rtc->dev->of_node->parent);
+ if (IS_ERR(rtc->rtc_map))
+ return PTR_ERR(rtc->rtc_map);
+
+ rtc->irq = platform_get_irq(pdev, 0);
+ if (rtc->irq < 0)
+ return rtc->irq;
+
+ ret = devm_request_irq(&pdev->dev, rtc->irq, cv1800_rtc_irq_handler,
+ IRQF_TRIGGER_HIGH, "alarm", &pdev->dev);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "cannot register interrupt handler\n");
+
+ rtc->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+ if (IS_ERR(rtc->clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(rtc->clk),
+ "clk not found\n");
+
+ platform_set_drvdata(pdev, rtc);
+
+ rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(rtc->rtc_dev))
+ return PTR_ERR(rtc->rtc_dev);
+
+ rtc->rtc_dev->ops = &cv800b_rtc_ops;
+ rtc->rtc_dev->range_max = U32_MAX;
+
+ /* if use internal clk,so coarse calibrate rtc */
+ regmap_read(rtc->rtc_map, CTRL, &ctrl_val);
+ ctrl_val &= CTRL_MODE_MASK;
+
+ if (ctrl_val == CTRL_MODE_OSC32K) {
+ ret = cv1800_rtc_32k_coarse_val_calib(rtc);
+ if (ret)
+ dev_err(&pdev->dev, "failed to coarse RTC val !\n");
+
+ ret = cv1800_rtc_32k_fine_val_calib(rtc);
+ if (ret)
+ dev_err(&pdev->dev, "failed to fine RTC val !\n");
+
+ rtc_enable_sec_counter(rtc);
+ }
+
+ return devm_rtc_register_device(rtc->rtc_dev);
+}
+
+static const struct of_device_id cv1800_dt_ids[] = {
+ { .compatible = "sophgo,cv1800b-rtc" },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, cv1800_dt_ids);
+
+static struct platform_driver cv1800_rtc_driver = {
+ .driver = {
+ .name = "sophgo-cv800b-rtc",
+ .of_match_table = cv1800_dt_ids,
+ },
+ .probe = cv1800_rtc_probe,
+};
+
+module_platform_driver(cv1800_rtc_driver);
+MODULE_AUTHOR("Jingbao Qiu");
+MODULE_DESCRIPTION("Sophgo cv1800 RTC Driver");
+MODULE_LICENSE("GPL");
--
2.43.0
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