diff options
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/rtc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/rtc/rtc-mpfs.c | 326 |
3 files changed, 337 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index a00f901b5c1d..68859970b4d5 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1973,4 +1973,14 @@ config RTC_DRV_MSC313 This driver can also be built as a module, if so, the module will be called "rtc-msc313". +config RTC_DRV_POLARFIRE_SOC + tristate "Microchip PolarFire SoC built-in RTC" + depends on SOC_MICROCHIP_POLARFIRE + help + If you say yes here you will get support for the + built-in RTC on Polarfire SoC. + + This driver can also be built as a module, if so, the module + will be called "rtc-mpfs". + endif # RTC_CLASS diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index fb04467b652d..35386b1c1e56 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -130,6 +130,7 @@ obj-$(CONFIG_RTC_DRV_PIC32) += rtc-pic32.o obj-$(CONFIG_RTC_DRV_PL030) += rtc-pl030.o obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o obj-$(CONFIG_RTC_DRV_PM8XXX) += rtc-pm8xxx.o +obj-$(CONFIG_RTC_DRV_POLARFIRE_SOC) += rtc-mpfs.o obj-$(CONFIG_RTC_DRV_PS3) += rtc-ps3.o obj-$(CONFIG_RTC_DRV_PXA) += rtc-pxa.o obj-$(CONFIG_RTC_DRV_R7301) += rtc-r7301.o diff --git a/drivers/rtc/rtc-mpfs.c b/drivers/rtc/rtc-mpfs.c new file mode 100644 index 000000000000..db9c638e50f7 --- /dev/null +++ b/drivers/rtc/rtc-mpfs.c @@ -0,0 +1,326 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Microchip MPFS RTC driver + * + * Copyright (c) 2021-2022 Microchip Corporation. All rights reserved. + * + * Author: Daire McNamara <daire.mcnamara@microchip.com> + * & Conor Dooley <conor.dooley@microchip.com> + */ +#include "linux/bits.h" +#include "linux/iopoll.h" +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm_wakeirq.h> +#include <linux/slab.h> +#include <linux/rtc.h> + +#define CONTROL_REG 0x00 +#define MODE_REG 0x04 +#define PRESCALER_REG 0x08 +#define ALARM_LOWER_REG 0x0c +#define ALARM_UPPER_REG 0x10 +#define COMPARE_LOWER_REG 0x14 +#define COMPARE_UPPER_REG 0x18 +#define DATETIME_LOWER_REG 0x20 +#define DATETIME_UPPER_REG 0x24 + +#define CONTROL_RUNNING_BIT BIT(0) +#define CONTROL_START_BIT BIT(0) +#define CONTROL_STOP_BIT BIT(1) +#define CONTROL_ALARM_ON_BIT BIT(2) +#define CONTROL_ALARM_OFF_BIT BIT(3) +#define CONTROL_RESET_BIT BIT(4) +#define CONTROL_UPLOAD_BIT BIT(5) +#define CONTROL_DOWNLOAD_BIT BIT(6) +#define CONTROL_MATCH_BIT BIT(7) +#define CONTROL_WAKEUP_CLR_BIT BIT(8) +#define CONTROL_WAKEUP_SET_BIT BIT(9) +#define CONTROL_UPDATED_BIT BIT(10) + +#define MODE_CLOCK_CALENDAR BIT(0) +#define MODE_WAKE_EN BIT(1) +#define MODE_WAKE_RESET BIT(2) +#define MODE_WAKE_CONTINUE BIT(3) + +#define MAX_PRESCALER_COUNT GENMASK(25, 0) +#define DATETIME_UPPER_MASK GENMASK(29, 0) +#define ALARM_UPPER_MASK GENMASK(10, 0) + +#define UPLOAD_TIMEOUT_US 50 + +struct mpfs_rtc_dev { + struct rtc_device *rtc; + void __iomem *base; +}; + +static void mpfs_rtc_start(struct mpfs_rtc_dev *rtcdev) +{ + u32 ctrl; + + ctrl = readl(rtcdev->base + CONTROL_REG); + ctrl &= ~CONTROL_STOP_BIT; + ctrl |= CONTROL_START_BIT; + writel(ctrl, rtcdev->base + CONTROL_REG); +} + +static void mpfs_rtc_clear_irq(struct mpfs_rtc_dev *rtcdev) +{ + u32 val = readl(rtcdev->base + CONTROL_REG); + + val &= ~(CONTROL_ALARM_ON_BIT | CONTROL_STOP_BIT); + val |= CONTROL_ALARM_OFF_BIT; + writel(val, rtcdev->base + CONTROL_REG); + /* + * Ensure that the posted write to the CONTROL_REG register completed before + * returning from this function. Not doing this may result in the interrupt + * only being cleared some time after this function returns. + */ + (void)readl(rtcdev->base + CONTROL_REG); +} + +static int mpfs_rtc_readtime(struct device *dev, struct rtc_time *tm) +{ + struct mpfs_rtc_dev *rtcdev = dev_get_drvdata(dev); + u64 time; + + time = readl(rtcdev->base + DATETIME_LOWER_REG); + time |= ((u64)readl(rtcdev->base + DATETIME_UPPER_REG) & DATETIME_UPPER_MASK) << 32; + rtc_time64_to_tm(time, tm); + + return 0; +} + +static int mpfs_rtc_settime(struct device *dev, struct rtc_time *tm) +{ + struct mpfs_rtc_dev *rtcdev = dev_get_drvdata(dev); + u32 ctrl, prog; + u64 time; + int ret; + + time = rtc_tm_to_time64(tm); + + writel((u32)time, rtcdev->base + DATETIME_LOWER_REG); + writel((u32)(time >> 32) & DATETIME_UPPER_MASK, rtcdev->base + DATETIME_UPPER_REG); + + ctrl = readl(rtcdev->base + CONTROL_REG); + ctrl &= ~CONTROL_STOP_BIT; + ctrl |= CONTROL_UPLOAD_BIT; + writel(ctrl, rtcdev->base + CONTROL_REG); + + ret = read_poll_timeout(readl, prog, prog & CONTROL_UPLOAD_BIT, 0, UPLOAD_TIMEOUT_US, + false, rtcdev->base + CONTROL_REG); + if (ret) { + dev_err(dev, "timed out uploading time to rtc"); + return ret; + } + mpfs_rtc_start(rtcdev); + + return 0; +} + +static int mpfs_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct mpfs_rtc_dev *rtcdev = dev_get_drvdata(dev); + u32 mode = readl(rtcdev->base + MODE_REG); + u64 time; + + alrm->enabled = mode & MODE_WAKE_EN; + + time = (u64)readl(rtcdev->base + ALARM_LOWER_REG) << 32; + time |= (readl(rtcdev->base + ALARM_UPPER_REG) & ALARM_UPPER_MASK); + rtc_time64_to_tm(time, &alrm->time); + + return 0; +} + +static int mpfs_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct mpfs_rtc_dev *rtcdev = dev_get_drvdata(dev); + u32 mode, ctrl; + u64 time; + + /* Disable the alarm before updating */ + ctrl = readl(rtcdev->base + CONTROL_REG); + ctrl |= CONTROL_ALARM_OFF_BIT; + writel(ctrl, rtcdev->base + CONTROL_REG); + + time = rtc_tm_to_time64(&alrm->time); + + writel((u32)time, rtcdev->base + ALARM_LOWER_REG); + writel((u32)(time >> 32) & ALARM_UPPER_MASK, rtcdev->base + ALARM_UPPER_REG); + + /* Bypass compare register in alarm mode */ + writel(GENMASK(31, 0), rtcdev->base + COMPARE_LOWER_REG); + writel(GENMASK(29, 0), rtcdev->base + COMPARE_UPPER_REG); + + /* Configure the RTC to enable the alarm. */ + ctrl = readl(rtcdev->base + CONTROL_REG); + mode = readl(rtcdev->base + MODE_REG); + if (alrm->enabled) { + mode = MODE_WAKE_EN | MODE_WAKE_CONTINUE; + /* Enable the alarm */ + ctrl &= ~CONTROL_ALARM_OFF_BIT; + ctrl |= CONTROL_ALARM_ON_BIT; + } + ctrl &= ~CONTROL_STOP_BIT; + ctrl |= CONTROL_START_BIT; + writel(ctrl, rtcdev->base + CONTROL_REG); + writel(mode, rtcdev->base + MODE_REG); + + return 0; +} + +static int mpfs_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct mpfs_rtc_dev *rtcdev = dev_get_drvdata(dev); + u32 ctrl; + + ctrl = readl(rtcdev->base + CONTROL_REG); + ctrl &= ~(CONTROL_ALARM_ON_BIT | CONTROL_ALARM_OFF_BIT | CONTROL_STOP_BIT); + + if (enabled) + ctrl |= CONTROL_ALARM_ON_BIT; + else + ctrl |= CONTROL_ALARM_OFF_BIT; + + writel(ctrl, rtcdev->base + CONTROL_REG); + + return 0; +} + +static inline struct clk *mpfs_rtc_init_clk(struct device *dev) +{ + struct clk *clk; + int ret; + + clk = devm_clk_get(dev, "rtc"); + if (IS_ERR(clk)) + return clk; + + ret = clk_prepare_enable(clk); + if (ret) + return ERR_PTR(ret); + + devm_add_action_or_reset(dev, (void (*) (void *))clk_disable_unprepare, clk); + return clk; +} + +static irqreturn_t mpfs_rtc_wakeup_irq_handler(int irq, void *dev) +{ + struct mpfs_rtc_dev *rtcdev = dev; + unsigned long pending; + + pending = readl(rtcdev->base + CONTROL_REG); + pending &= CONTROL_ALARM_ON_BIT; + mpfs_rtc_clear_irq(rtcdev); + + rtc_update_irq(rtcdev->rtc, 1, RTC_IRQF | RTC_AF); + + return IRQ_HANDLED; +} + +static const struct rtc_class_ops mpfs_rtc_ops = { + .read_time = mpfs_rtc_readtime, + .set_time = mpfs_rtc_settime, + .read_alarm = mpfs_rtc_readalarm, + .set_alarm = mpfs_rtc_setalarm, + .alarm_irq_enable = mpfs_rtc_alarm_irq_enable, +}; + +static int mpfs_rtc_probe(struct platform_device *pdev) +{ + struct mpfs_rtc_dev *rtcdev; + struct clk *clk; + u32 prescaler; + int wakeup_irq, ret; + + rtcdev = devm_kzalloc(&pdev->dev, sizeof(struct mpfs_rtc_dev), GFP_KERNEL); + if (!rtcdev) + return -ENOMEM; + + platform_set_drvdata(pdev, rtcdev); + + rtcdev->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtcdev->rtc)) + return PTR_ERR(rtcdev->rtc); + + rtcdev->rtc->ops = &mpfs_rtc_ops; + + /* range is capped by alarm max, lower reg is 31:0 & upper is 10:0 */ + rtcdev->rtc->range_max = GENMASK_ULL(42, 0); + + clk = mpfs_rtc_init_clk(&pdev->dev); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + rtcdev->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(rtcdev->base)) { + dev_dbg(&pdev->dev, "invalid ioremap resources\n"); + return PTR_ERR(rtcdev->base); + } + + wakeup_irq = platform_get_irq(pdev, 0); + if (wakeup_irq <= 0) { + dev_dbg(&pdev->dev, "could not get wakeup irq\n"); + return wakeup_irq; + } + ret = devm_request_irq(&pdev->dev, wakeup_irq, mpfs_rtc_wakeup_irq_handler, 0, + dev_name(&pdev->dev), rtcdev); + if (ret) { + dev_dbg(&pdev->dev, "could not request wakeup irq\n"); + return ret; + } + + /* prescaler hardware adds 1 to reg value */ + prescaler = clk_get_rate(devm_clk_get(&pdev->dev, "rtcref")) - 1; + + if (prescaler > MAX_PRESCALER_COUNT) { + dev_dbg(&pdev->dev, "invalid prescaler %d\n", prescaler); + return -EINVAL; + } + + writel(prescaler, rtcdev->base + PRESCALER_REG); + dev_info(&pdev->dev, "prescaler set to: 0x%X \r\n", prescaler); + + device_init_wakeup(&pdev->dev, true); + ret = dev_pm_set_wake_irq(&pdev->dev, wakeup_irq); + if (ret) + dev_err(&pdev->dev, "failed to enable irq wake\n"); + + return devm_rtc_register_device(rtcdev->rtc); +} + +static int mpfs_rtc_remove(struct platform_device *pdev) +{ + dev_pm_clear_wake_irq(&pdev->dev); + + return 0; +} + +static const struct of_device_id mpfs_rtc_of_match[] = { + { .compatible = "microchip,mpfs-rtc" }, + { } +}; + +MODULE_DEVICE_TABLE(of, mpfs_rtc_of_match); + +static struct platform_driver mpfs_rtc_driver = { + .probe = mpfs_rtc_probe, + .remove = mpfs_rtc_remove, + .driver = { + .name = "mpfs_rtc", + .of_match_table = mpfs_rtc_of_match, + }, +}; + +module_platform_driver(mpfs_rtc_driver); + +MODULE_DESCRIPTION("Real time clock for Microchip Polarfire SoC"); +MODULE_AUTHOR("Daire McNamara <daire.mcnamara@microchip.com>"); +MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>"); +MODULE_LICENSE("GPL"); |