diff options
Diffstat (limited to 'drivers/rtc/rtc-pm8xxx.c')
| -rw-r--r-- | drivers/rtc/rtc-pm8xxx.c | 220 |
1 files changed, 175 insertions, 45 deletions
diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c index b2518aea4218..3c1dddcc81df 100644 --- a/drivers/rtc/rtc-pm8xxx.c +++ b/drivers/rtc/rtc-pm8xxx.c @@ -5,6 +5,7 @@ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. * Copyright (c) 2023, Linaro Limited */ +#include <linux/efi.h> #include <linux/of.h> #include <linux/module.h> #include <linux/nvmem-consumer.h> @@ -16,9 +17,10 @@ #include <linux/regmap.h> #include <linux/slab.h> #include <linux/spinlock.h> - #include <linux/unaligned.h> +#include <asm/byteorder.h> + /* RTC_CTRL register bit fields */ #define PM8xxx_RTC_ENABLE BIT(7) #define PM8xxx_RTC_ALARM_CLEAR BIT(0) @@ -46,28 +48,125 @@ struct pm8xxx_rtc_regs { unsigned int alarm_en; }; +struct qcom_uefi_rtc_info { + __le32 offset_gps; + u8 reserved[8]; +} __packed; + /** * 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 + * @use_uefi: use UEFI variable as fallback for offset * @alarm_irq: alarm irq number * @regs: register description * @dev: device structure + * @rtc_info: qcom uefi rtc-info structure * @nvmem_cell: nvmem cell for offset * @offset: offset from epoch in seconds + * @offset_dirty: offset needs to be stored on shutdown */ struct pm8xxx_rtc { struct rtc_device *rtc; struct regmap *regmap; bool allow_set_time; + bool use_uefi; int alarm_irq; const struct pm8xxx_rtc_regs *regs; struct device *dev; + struct qcom_uefi_rtc_info rtc_info; struct nvmem_cell *nvmem_cell; u32 offset; + bool offset_dirty; }; +#ifdef CONFIG_EFI + +MODULE_IMPORT_NS("EFIVAR"); + +#define QCOM_UEFI_NAME L"RTCInfo" +#define QCOM_UEFI_GUID EFI_GUID(0x882f8c2b, 0x9646, 0x435f, \ + 0x8d, 0xe5, 0xf2, 0x08, 0xff, 0x80, 0xc1, 0xbd) +#define QCOM_UEFI_ATTRS (EFI_VARIABLE_NON_VOLATILE | \ + EFI_VARIABLE_BOOTSERVICE_ACCESS | \ + EFI_VARIABLE_RUNTIME_ACCESS) + +static int pm8xxx_rtc_read_uefi_offset(struct pm8xxx_rtc *rtc_dd) +{ + struct qcom_uefi_rtc_info *rtc_info = &rtc_dd->rtc_info; + unsigned long size = sizeof(*rtc_info); + struct device *dev = rtc_dd->dev; + efi_status_t status; + u32 offset_gps; + int rc; + + rc = efivar_lock(); + if (rc) + return rc; + + status = efivar_get_variable(QCOM_UEFI_NAME, &QCOM_UEFI_GUID, NULL, + &size, rtc_info); + efivar_unlock(); + + if (status != EFI_SUCCESS) { + dev_dbg(dev, "failed to read UEFI offset: %lu\n", status); + return efi_status_to_err(status); + } + + if (size != sizeof(*rtc_info)) { + dev_dbg(dev, "unexpected UEFI structure size %lu\n", size); + return -EINVAL; + } + + dev_dbg(dev, "uefi_rtc_info = %*ph\n", (int)size, rtc_info); + + /* Convert from GPS to Unix time offset */ + offset_gps = le32_to_cpu(rtc_info->offset_gps); + rtc_dd->offset = offset_gps + (u32)RTC_TIMESTAMP_EPOCH_GPS; + + return 0; +} + +static int pm8xxx_rtc_write_uefi_offset(struct pm8xxx_rtc *rtc_dd, u32 offset) +{ + struct qcom_uefi_rtc_info *rtc_info = &rtc_dd->rtc_info; + unsigned long size = sizeof(*rtc_info); + struct device *dev = rtc_dd->dev; + efi_status_t status; + u32 offset_gps; + + /* Convert from Unix to GPS time offset */ + offset_gps = offset - (u32)RTC_TIMESTAMP_EPOCH_GPS; + + rtc_info->offset_gps = cpu_to_le32(offset_gps); + + dev_dbg(dev, "efi_rtc_info = %*ph\n", (int)size, rtc_info); + + status = efivar_set_variable(QCOM_UEFI_NAME, &QCOM_UEFI_GUID, + QCOM_UEFI_ATTRS, size, rtc_info); + if (status != EFI_SUCCESS) { + dev_dbg(dev, "failed to write UEFI offset: %lx\n", status); + return efi_status_to_err(status); + } + + return 0; +} + +#else /* CONFIG_EFI */ + +static int pm8xxx_rtc_read_uefi_offset(struct pm8xxx_rtc *rtc_dd) +{ + return -ENODEV; +} + +static int pm8xxx_rtc_write_uefi_offset(struct pm8xxx_rtc *rtc_dd, u32 offset) +{ + return -ENODEV; +} + +#endif /* CONFIG_EFI */ + static int pm8xxx_rtc_read_nvmem_offset(struct pm8xxx_rtc *rtc_dd) { size_t len; @@ -110,14 +209,6 @@ static int pm8xxx_rtc_write_nvmem_offset(struct pm8xxx_rtc *rtc_dd, u32 offset) 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; @@ -155,7 +246,7 @@ static int pm8xxx_rtc_update_offset(struct pm8xxx_rtc *rtc_dd, u32 secs) u32 offset; int rc; - if (!rtc_dd->nvmem_cell) + if (!rtc_dd->nvmem_cell && !rtc_dd->use_uefi) return -ENODEV; rc = pm8xxx_rtc_read_raw(rtc_dd, &raw_secs); @@ -167,10 +258,25 @@ static int pm8xxx_rtc_update_offset(struct pm8xxx_rtc *rtc_dd, u32 secs) if (offset == rtc_dd->offset) return 0; - rc = pm8xxx_rtc_write_nvmem_offset(rtc_dd, offset); + /* + * Reduce flash wear by deferring updates due to clock drift until + * shutdown. + */ + if (abs_diff(offset, rtc_dd->offset) < 30) { + rtc_dd->offset_dirty = true; + goto out; + } + + if (rtc_dd->nvmem_cell) + rc = pm8xxx_rtc_write_nvmem_offset(rtc_dd, offset); + else + rc = pm8xxx_rtc_write_uefi_offset(rtc_dd, offset); + if (rc) return rc; + rtc_dd->offset_dirty = false; +out: rtc_dd->offset = offset; return 0; @@ -455,6 +561,30 @@ static const struct of_device_id pm8xxx_id_table[] = { }; MODULE_DEVICE_TABLE(of, pm8xxx_id_table); +static int pm8xxx_rtc_probe_offset(struct pm8xxx_rtc *rtc_dd) +{ + int rc; + + rtc_dd->nvmem_cell = devm_nvmem_cell_get(rtc_dd->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; + } else { + return pm8xxx_rtc_read_nvmem_offset(rtc_dd); + } + + /* Use UEFI storage as fallback if available */ + if (efivar_is_available()) { + rc = pm8xxx_rtc_read_uefi_offset(rtc_dd); + if (rc == 0) + rtc_dd->use_uefi = true; + } + + return 0; +} + static int pm8xxx_rtc_probe(struct platform_device *pdev) { const struct of_device_id *match; @@ -469,30 +599,23 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev) if (rtc_dd == NULL) return -ENOMEM; + rtc_dd->regs = match->data; + rtc_dd->dev = &pdev->dev; + 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; + if (!of_property_read_bool(pdev->dev.of_node, "qcom,no-alarm")) { + 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); + rc = pm8xxx_rtc_probe_offset(rtc_dd); if (rc) return rc; } @@ -503,8 +626,6 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev) platform_set_drvdata(pdev, rtc_dd); - device_init_wakeup(&pdev->dev, true); - rtc_dd->rtc = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(rtc_dd->rtc)) return PTR_ERR(rtc_dd->rtc); @@ -512,32 +633,41 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev) 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; + if (rtc_dd->alarm_irq) { + 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 = devm_pm_set_wake_irq(&pdev->dev, rtc_dd->alarm_irq); + if (rc) + return rc; - rc = dev_pm_set_wake_irq(&pdev->dev, rtc_dd->alarm_irq); - if (rc) - return rc; + devm_device_init_wakeup(&pdev->dev); + } else { + clear_bit(RTC_FEATURE_ALARM, rtc_dd->rtc->features); + } - return 0; + return devm_rtc_register_device(rtc_dd->rtc); } -static void pm8xxx_remove(struct platform_device *pdev) +static void pm8xxx_shutdown(struct platform_device *pdev) { - dev_pm_clear_wake_irq(&pdev->dev); + struct pm8xxx_rtc *rtc_dd = platform_get_drvdata(pdev); + + if (rtc_dd->offset_dirty) { + if (rtc_dd->nvmem_cell) + pm8xxx_rtc_write_nvmem_offset(rtc_dd, rtc_dd->offset); + else + pm8xxx_rtc_write_uefi_offset(rtc_dd, rtc_dd->offset); + } } static struct platform_driver pm8xxx_rtc_driver = { .probe = pm8xxx_rtc_probe, - .remove = pm8xxx_remove, + .shutdown = pm8xxx_shutdown, .driver = { .name = "rtc-pm8xxx", .of_match_table = pm8xxx_id_table, |