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drivers: rtc: add rpi-rtc driver for Raspberry Pi 5
Ported from: Repository: https://github.com/raspberrypi/linux/ Branch: rpi-6.6.y Revision: da87f91ad8450ccc5274cd7b6ba8d823b396c96f Signed-off-by: Dimitrios Poulios <[email protected]>
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,277 @@ | ||
| // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause | ||
| /** | ||
| * rtc-rpi.c | ||
| * | ||
| * RTC driver using firmware mailbox | ||
| * Supports battery backed RTC and wake alarms | ||
| * | ||
| * Based on rtc-meson-vrtc by Neil Armstrong | ||
| * | ||
| * Copyright (c) 2023, Raspberry Pi Ltd. | ||
| */ | ||
|
|
||
| #include <linux/module.h> | ||
| #include <linux/platform_device.h> | ||
| #include <linux/rtc.h> | ||
| #include <linux/of.h> | ||
| #include <soc/bcm2835/raspberrypi-firmware.h> | ||
|
|
||
| struct rpi_rtc_data { | ||
| struct rtc_device *rtc; | ||
| struct rpi_firmware *fw; | ||
| u32 bbat_vchg_microvolts; | ||
| }; | ||
|
|
||
| #define RPI_FIRMWARE_GET_RTC_REG 0x00030087 | ||
| #define RPI_FIRMWARE_SET_RTC_REG 0x00038087 | ||
|
|
||
| enum { | ||
| RTC_TIME, | ||
| RTC_ALARM, | ||
| RTC_ALARM_PENDING, | ||
| RTC_ALARM_ENABLE, | ||
| RTC_BBAT_CHG_VOLTS, | ||
| RTC_BBAT_CHG_VOLTS_MIN, | ||
| RTC_BBAT_CHG_VOLTS_MAX, | ||
| RTC_BBAT_VOLTS | ||
| }; | ||
|
|
||
| static int rpi_rtc_read_time(struct device *dev, struct rtc_time *tm) | ||
| { | ||
| struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); | ||
| u32 data[2] = {RTC_TIME}; | ||
| int err; | ||
|
|
||
| err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, | ||
| &data, sizeof(data)); | ||
| rtc_time64_to_tm(data[1], tm); | ||
| return err; | ||
| } | ||
|
|
||
| static int rpi_rtc_set_time(struct device *dev, struct rtc_time *tm) | ||
| { | ||
| struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); | ||
| u32 data[2] = {RTC_TIME, rtc_tm_to_time64(tm)}; | ||
|
|
||
| return rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_SET_RTC_REG, | ||
| &data, sizeof(data)); | ||
| } | ||
|
|
||
| static int rpi_rtc_alarm_irq_is_enabled(struct device *dev, unsigned char *enabled) | ||
| { | ||
| struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); | ||
| u32 data[2] = {RTC_ALARM_ENABLE}; | ||
| s32 err = 0; | ||
|
|
||
| err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, | ||
| &data, sizeof(data)); | ||
| *enabled = data[1] & 0x1; | ||
| return err; | ||
| } | ||
|
|
||
| static int rpi_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) | ||
| { | ||
| struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); | ||
| u32 data[2] = {RTC_ALARM_ENABLE, enabled}; | ||
|
|
||
| return rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_SET_RTC_REG, | ||
| &data, sizeof(data)); | ||
| } | ||
|
|
||
| static int rpi_rtc_alarm_clear_pending(struct device *dev) | ||
| { | ||
| struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); | ||
| u32 data[2] = {RTC_ALARM_PENDING, 1}; | ||
|
|
||
| return rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_SET_RTC_REG, | ||
| &data, sizeof(data)); | ||
| } | ||
|
|
||
| static int rpi_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) | ||
| { | ||
| struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); | ||
| u32 data[2] = {RTC_ALARM}; | ||
| s32 err = 0; | ||
|
|
||
| err = rpi_rtc_alarm_irq_is_enabled(dev, &alarm->enabled); | ||
| if (!err) | ||
| err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, | ||
| &data, sizeof(data)); | ||
| rtc_time64_to_tm(data[1], &alarm->time); | ||
|
|
||
| return err; | ||
| } | ||
|
|
||
| static int rpi_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) | ||
| { | ||
| struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); | ||
| u32 data[2] = {RTC_ALARM, rtc_tm_to_time64(&alarm->time)}; | ||
| int err; | ||
|
|
||
| err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_SET_RTC_REG, | ||
| &data, sizeof(data)); | ||
|
|
||
| if (err == 0) | ||
| err = rpi_rtc_alarm_irq_enable(dev, alarm->enabled); | ||
|
|
||
| return err; | ||
| } | ||
|
|
||
| static const struct rtc_class_ops rpi_rtc_ops = { | ||
| .read_time = rpi_rtc_read_time, | ||
| .set_time = rpi_rtc_set_time, | ||
| .read_alarm = rpi_rtc_read_alarm, | ||
| .set_alarm = rpi_rtc_set_alarm, | ||
| .alarm_irq_enable = rpi_rtc_alarm_irq_enable, | ||
| }; | ||
|
|
||
| static int rpi_rtc_set_charge_voltage(struct device *dev) | ||
| { | ||
| struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); | ||
| u32 data[2] = {RTC_BBAT_CHG_VOLTS, vrtc->bbat_vchg_microvolts}; | ||
| int err; | ||
|
|
||
| err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_SET_RTC_REG, | ||
| &data, sizeof(data)); | ||
|
|
||
| if (err) | ||
| dev_err(dev, "failed to set trickle charge voltage to %uuV: %d\n", | ||
| vrtc->bbat_vchg_microvolts, err); | ||
| else if (vrtc->bbat_vchg_microvolts) | ||
| dev_info(dev, "trickle charging enabled at %uuV\n", | ||
| vrtc->bbat_vchg_microvolts); | ||
|
|
||
| return err; | ||
| } | ||
|
|
||
| static ssize_t rpi_rtc_print_uint_reg(struct device *dev, char *buf, u32 reg) | ||
| { | ||
| struct rpi_rtc_data *vrtc = dev_get_drvdata(dev->parent); | ||
| u32 data[2] = {reg, 0}; | ||
| int ret = 0; | ||
|
|
||
| ret = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, | ||
| &data, sizeof(data)); | ||
| if (ret < 0) | ||
| return ret; | ||
|
|
||
| return sprintf(buf, "%u\n", data[1]); | ||
| } | ||
|
|
||
| static ssize_t charging_voltage_show(struct device *dev, | ||
| struct device_attribute *attr, | ||
| char *buf) | ||
| { | ||
| return rpi_rtc_print_uint_reg(dev, buf, RTC_BBAT_CHG_VOLTS); | ||
| } | ||
| static DEVICE_ATTR_RO(charging_voltage); | ||
|
|
||
| static ssize_t charging_voltage_min_show(struct device *dev, | ||
| struct device_attribute *attr, | ||
| char *buf) | ||
| { | ||
| return rpi_rtc_print_uint_reg(dev, buf, RTC_BBAT_CHG_VOLTS_MIN); | ||
| } | ||
| static DEVICE_ATTR_RO(charging_voltage_min); | ||
|
|
||
| static ssize_t charging_voltage_max_show(struct device *dev, | ||
| struct device_attribute *attr, | ||
| char *buf) | ||
| { | ||
| return rpi_rtc_print_uint_reg(dev, buf, RTC_BBAT_CHG_VOLTS_MAX); | ||
| } | ||
| static DEVICE_ATTR_RO(charging_voltage_max); | ||
|
|
||
| static ssize_t battery_voltage_show(struct device *dev, | ||
| struct device_attribute *attr, | ||
| char *buf) | ||
| { | ||
| return rpi_rtc_print_uint_reg(dev, buf, RTC_BBAT_VOLTS); | ||
| } | ||
| static DEVICE_ATTR_RO(battery_voltage); | ||
|
|
||
| static struct attribute *rpi_rtc_attrs[] = { | ||
| &dev_attr_charging_voltage.attr, | ||
| &dev_attr_charging_voltage_min.attr, | ||
| &dev_attr_charging_voltage_max.attr, | ||
| &dev_attr_battery_voltage.attr, | ||
| NULL | ||
| }; | ||
|
|
||
| static const struct attribute_group rpi_rtc_sysfs_files = { | ||
| .attrs = rpi_rtc_attrs, | ||
| }; | ||
|
|
||
| static int rpi_rtc_probe(struct platform_device *pdev) | ||
| { | ||
| struct rpi_rtc_data *vrtc; | ||
| struct device *dev = &pdev->dev; | ||
| struct device_node *np = dev->of_node; | ||
| struct device_node *fw_node; | ||
| struct rpi_firmware *fw; | ||
| int ret; | ||
|
|
||
| fw_node = of_parse_phandle(np, "firmware", 0); | ||
| if (!fw_node) { | ||
| dev_err(dev, "Missing firmware node\n"); | ||
| return -ENOENT; | ||
| } | ||
|
|
||
| fw = rpi_firmware_get(fw_node); | ||
| if (!fw) | ||
| return -EPROBE_DEFER; | ||
|
|
||
| vrtc = devm_kzalloc(&pdev->dev, sizeof(*vrtc), GFP_KERNEL); | ||
| if (!vrtc) | ||
| return -ENOMEM; | ||
|
|
||
| vrtc->fw = fw; | ||
|
|
||
| device_init_wakeup(&pdev->dev, 1); | ||
|
|
||
| platform_set_drvdata(pdev, vrtc); | ||
|
|
||
| vrtc->rtc = devm_rtc_allocate_device(&pdev->dev); | ||
| if (IS_ERR(vrtc->rtc)) | ||
| return PTR_ERR(vrtc->rtc); | ||
|
|
||
| set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, vrtc->rtc->features); | ||
| clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, vrtc->rtc->features); | ||
|
|
||
| vrtc->rtc->ops = &rpi_rtc_ops; | ||
| ret = rtc_add_group(vrtc->rtc, &rpi_rtc_sysfs_files); | ||
| if (ret) | ||
| return ret; | ||
|
|
||
| rpi_rtc_alarm_clear_pending(dev); | ||
|
|
||
| /* | ||
| * Optionally enable trickle charging - if the property isn't | ||
| * present (or set to zero), trickle charging is disabled. | ||
| */ | ||
| of_property_read_u32(np, "trickle-charge-microvolt", | ||
| &vrtc->bbat_vchg_microvolts); | ||
|
|
||
| rpi_rtc_set_charge_voltage(dev); | ||
|
|
||
| return devm_rtc_register_device(vrtc->rtc); | ||
| } | ||
|
|
||
| static const struct of_device_id rpi_rtc_dt_match[] = { | ||
| { .compatible = "raspberrypi,rpi-rtc"}, | ||
| {}, | ||
| }; | ||
| MODULE_DEVICE_TABLE(of, rpi_rtc_dt_match); | ||
|
|
||
| static struct platform_driver rpi_rtc_driver = { | ||
| .probe = rpi_rtc_probe, | ||
| .driver = { | ||
| .name = "rpi-rtc", | ||
| .of_match_table = rpi_rtc_dt_match, | ||
| }, | ||
| }; | ||
|
|
||
| module_platform_driver(rpi_rtc_driver); | ||
|
|
||
| MODULE_DESCRIPTION("Raspberry Pi RTC driver"); | ||
| MODULE_LICENSE("GPL"); |