From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/rtc/rtc-armada38x.c | 591 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 591 insertions(+) create mode 100644 drivers/rtc/rtc-armada38x.c (limited to 'drivers/rtc/rtc-armada38x.c') diff --git a/drivers/rtc/rtc-armada38x.c b/drivers/rtc/rtc-armada38x.c new file mode 100644 index 000000000..cc542e6b1 --- /dev/null +++ b/drivers/rtc/rtc-armada38x.c @@ -0,0 +1,591 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * RTC driver for the Armada 38x Marvell SoCs + * + * Copyright (C) 2015 Marvell + * + * Gregory Clement + */ + +#include +#include +#include +#include +#include +#include +#include + +#define RTC_STATUS 0x0 +#define RTC_STATUS_ALARM1 BIT(0) +#define RTC_STATUS_ALARM2 BIT(1) +#define RTC_IRQ1_CONF 0x4 +#define RTC_IRQ2_CONF 0x8 +#define RTC_IRQ_AL_EN BIT(0) +#define RTC_IRQ_FREQ_EN BIT(1) +#define RTC_IRQ_FREQ_1HZ BIT(2) +#define RTC_CCR 0x18 +#define RTC_CCR_MODE BIT(15) +#define RTC_CONF_TEST 0x1C +#define RTC_NOMINAL_TIMING BIT(13) + +#define RTC_TIME 0xC +#define RTC_ALARM1 0x10 +#define RTC_ALARM2 0x14 + +/* Armada38x SoC registers */ +#define RTC_38X_BRIDGE_TIMING_CTL 0x0 +#define RTC_38X_PERIOD_OFFS 0 +#define RTC_38X_PERIOD_MASK (0x3FF << RTC_38X_PERIOD_OFFS) +#define RTC_38X_READ_DELAY_OFFS 26 +#define RTC_38X_READ_DELAY_MASK (0x1F << RTC_38X_READ_DELAY_OFFS) + +/* Armada 7K/8K registers */ +#define RTC_8K_BRIDGE_TIMING_CTL0 0x0 +#define RTC_8K_WRCLK_PERIOD_OFFS 0 +#define RTC_8K_WRCLK_PERIOD_MASK (0xFFFF << RTC_8K_WRCLK_PERIOD_OFFS) +#define RTC_8K_WRCLK_SETUP_OFFS 16 +#define RTC_8K_WRCLK_SETUP_MASK (0xFFFF << RTC_8K_WRCLK_SETUP_OFFS) +#define RTC_8K_BRIDGE_TIMING_CTL1 0x4 +#define RTC_8K_READ_DELAY_OFFS 0 +#define RTC_8K_READ_DELAY_MASK (0xFFFF << RTC_8K_READ_DELAY_OFFS) + +#define RTC_8K_ISR 0x10 +#define RTC_8K_IMR 0x14 +#define RTC_8K_ALARM2 BIT(0) + +#define SOC_RTC_INTERRUPT 0x8 +#define SOC_RTC_ALARM1 BIT(0) +#define SOC_RTC_ALARM2 BIT(1) +#define SOC_RTC_ALARM1_MASK BIT(2) +#define SOC_RTC_ALARM2_MASK BIT(3) + +#define SAMPLE_NR 100 + +struct value_to_freq { + u32 value; + u8 freq; +}; + +struct armada38x_rtc { + struct rtc_device *rtc_dev; + void __iomem *regs; + void __iomem *regs_soc; + spinlock_t lock; + int irq; + bool initialized; + struct value_to_freq *val_to_freq; + const struct armada38x_rtc_data *data; +}; + +#define ALARM1 0 +#define ALARM2 1 + +#define ALARM_REG(base, alarm) ((base) + (alarm) * sizeof(u32)) + +struct armada38x_rtc_data { + /* Initialize the RTC-MBUS bridge timing */ + void (*update_mbus_timing)(struct armada38x_rtc *rtc); + u32 (*read_rtc_reg)(struct armada38x_rtc *rtc, u8 rtc_reg); + void (*clear_isr)(struct armada38x_rtc *rtc); + void (*unmask_interrupt)(struct armada38x_rtc *rtc); + u32 alarm; +}; + +/* + * According to the datasheet, the OS should wait 5us after every + * register write to the RTC hard macro so that the required update + * can occur without holding off the system bus + * According to errata RES-3124064, Write to any RTC register + * may fail. As a workaround, before writing to RTC + * register, issue a dummy write of 0x0 twice to RTC Status + * register. + */ + +static void rtc_delayed_write(u32 val, struct armada38x_rtc *rtc, int offset) +{ + writel(0, rtc->regs + RTC_STATUS); + writel(0, rtc->regs + RTC_STATUS); + writel(val, rtc->regs + offset); + udelay(5); +} + +/* Update RTC-MBUS bridge timing parameters */ +static void rtc_update_38x_mbus_timing_params(struct armada38x_rtc *rtc) +{ + u32 reg; + + reg = readl(rtc->regs_soc + RTC_38X_BRIDGE_TIMING_CTL); + reg &= ~RTC_38X_PERIOD_MASK; + reg |= 0x3FF << RTC_38X_PERIOD_OFFS; /* Maximum value */ + reg &= ~RTC_38X_READ_DELAY_MASK; + reg |= 0x1F << RTC_38X_READ_DELAY_OFFS; /* Maximum value */ + writel(reg, rtc->regs_soc + RTC_38X_BRIDGE_TIMING_CTL); +} + +static void rtc_update_8k_mbus_timing_params(struct armada38x_rtc *rtc) +{ + u32 reg; + + reg = readl(rtc->regs_soc + RTC_8K_BRIDGE_TIMING_CTL0); + reg &= ~RTC_8K_WRCLK_PERIOD_MASK; + reg |= 0x3FF << RTC_8K_WRCLK_PERIOD_OFFS; + reg &= ~RTC_8K_WRCLK_SETUP_MASK; + reg |= 0x29 << RTC_8K_WRCLK_SETUP_OFFS; + writel(reg, rtc->regs_soc + RTC_8K_BRIDGE_TIMING_CTL0); + + reg = readl(rtc->regs_soc + RTC_8K_BRIDGE_TIMING_CTL1); + reg &= ~RTC_8K_READ_DELAY_MASK; + reg |= 0x3F << RTC_8K_READ_DELAY_OFFS; + writel(reg, rtc->regs_soc + RTC_8K_BRIDGE_TIMING_CTL1); +} + +static u32 read_rtc_register(struct armada38x_rtc *rtc, u8 rtc_reg) +{ + return readl(rtc->regs + rtc_reg); +} + +static u32 read_rtc_register_38x_wa(struct armada38x_rtc *rtc, u8 rtc_reg) +{ + int i, index_max = 0, max = 0; + + for (i = 0; i < SAMPLE_NR; i++) { + rtc->val_to_freq[i].value = readl(rtc->regs + rtc_reg); + rtc->val_to_freq[i].freq = 0; + } + + for (i = 0; i < SAMPLE_NR; i++) { + int j = 0; + u32 value = rtc->val_to_freq[i].value; + + while (rtc->val_to_freq[j].freq) { + if (rtc->val_to_freq[j].value == value) { + rtc->val_to_freq[j].freq++; + break; + } + j++; + } + + if (!rtc->val_to_freq[j].freq) { + rtc->val_to_freq[j].value = value; + rtc->val_to_freq[j].freq = 1; + } + + if (rtc->val_to_freq[j].freq > max) { + index_max = j; + max = rtc->val_to_freq[j].freq; + } + + /* + * If a value already has half of the sample this is the most + * frequent one and we can stop the research right now + */ + if (max > SAMPLE_NR / 2) + break; + } + + return rtc->val_to_freq[index_max].value; +} + +static void armada38x_clear_isr(struct armada38x_rtc *rtc) +{ + u32 val = readl(rtc->regs_soc + SOC_RTC_INTERRUPT); + + writel(val & ~SOC_RTC_ALARM1, rtc->regs_soc + SOC_RTC_INTERRUPT); +} + +static void armada38x_unmask_interrupt(struct armada38x_rtc *rtc) +{ + u32 val = readl(rtc->regs_soc + SOC_RTC_INTERRUPT); + + writel(val | SOC_RTC_ALARM1_MASK, rtc->regs_soc + SOC_RTC_INTERRUPT); +} + +static void armada8k_clear_isr(struct armada38x_rtc *rtc) +{ + writel(RTC_8K_ALARM2, rtc->regs_soc + RTC_8K_ISR); +} + +static void armada8k_unmask_interrupt(struct armada38x_rtc *rtc) +{ + writel(RTC_8K_ALARM2, rtc->regs_soc + RTC_8K_IMR); +} + +static int armada38x_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct armada38x_rtc *rtc = dev_get_drvdata(dev); + unsigned long time, flags; + + spin_lock_irqsave(&rtc->lock, flags); + time = rtc->data->read_rtc_reg(rtc, RTC_TIME); + spin_unlock_irqrestore(&rtc->lock, flags); + + rtc_time64_to_tm(time, tm); + + return 0; +} + +static void armada38x_rtc_reset(struct armada38x_rtc *rtc) +{ + u32 reg; + + reg = rtc->data->read_rtc_reg(rtc, RTC_CONF_TEST); + /* If bits [7:0] are non-zero, assume RTC was uninitialized */ + if (reg & 0xff) { + rtc_delayed_write(0, rtc, RTC_CONF_TEST); + msleep(500); /* Oscillator startup time */ + rtc_delayed_write(0, rtc, RTC_TIME); + rtc_delayed_write(SOC_RTC_ALARM1 | SOC_RTC_ALARM2, rtc, + RTC_STATUS); + rtc_delayed_write(RTC_NOMINAL_TIMING, rtc, RTC_CCR); + } + rtc->initialized = true; +} + +static int armada38x_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct armada38x_rtc *rtc = dev_get_drvdata(dev); + unsigned long time, flags; + + time = rtc_tm_to_time64(tm); + + if (!rtc->initialized) + armada38x_rtc_reset(rtc); + + spin_lock_irqsave(&rtc->lock, flags); + rtc_delayed_write(time, rtc, RTC_TIME); + spin_unlock_irqrestore(&rtc->lock, flags); + + return 0; +} + +static int armada38x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct armada38x_rtc *rtc = dev_get_drvdata(dev); + unsigned long time, flags; + u32 reg = ALARM_REG(RTC_ALARM1, rtc->data->alarm); + u32 reg_irq = ALARM_REG(RTC_IRQ1_CONF, rtc->data->alarm); + u32 val; + + spin_lock_irqsave(&rtc->lock, flags); + + time = rtc->data->read_rtc_reg(rtc, reg); + val = rtc->data->read_rtc_reg(rtc, reg_irq) & RTC_IRQ_AL_EN; + + spin_unlock_irqrestore(&rtc->lock, flags); + + alrm->enabled = val ? 1 : 0; + rtc_time64_to_tm(time, &alrm->time); + + return 0; +} + +static int armada38x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct armada38x_rtc *rtc = dev_get_drvdata(dev); + u32 reg = ALARM_REG(RTC_ALARM1, rtc->data->alarm); + u32 reg_irq = ALARM_REG(RTC_IRQ1_CONF, rtc->data->alarm); + unsigned long time, flags; + + time = rtc_tm_to_time64(&alrm->time); + + spin_lock_irqsave(&rtc->lock, flags); + + rtc_delayed_write(time, rtc, reg); + + if (alrm->enabled) { + rtc_delayed_write(RTC_IRQ_AL_EN, rtc, reg_irq); + rtc->data->unmask_interrupt(rtc); + } + + spin_unlock_irqrestore(&rtc->lock, flags); + + return 0; +} + +static int armada38x_rtc_alarm_irq_enable(struct device *dev, + unsigned int enabled) +{ + struct armada38x_rtc *rtc = dev_get_drvdata(dev); + u32 reg_irq = ALARM_REG(RTC_IRQ1_CONF, rtc->data->alarm); + unsigned long flags; + + spin_lock_irqsave(&rtc->lock, flags); + + if (enabled) + rtc_delayed_write(RTC_IRQ_AL_EN, rtc, reg_irq); + else + rtc_delayed_write(0, rtc, reg_irq); + + spin_unlock_irqrestore(&rtc->lock, flags); + + return 0; +} + +static irqreturn_t armada38x_rtc_alarm_irq(int irq, void *data) +{ + struct armada38x_rtc *rtc = data; + u32 val; + int event = RTC_IRQF | RTC_AF; + u32 reg_irq = ALARM_REG(RTC_IRQ1_CONF, rtc->data->alarm); + + dev_dbg(&rtc->rtc_dev->dev, "%s:irq(%d)\n", __func__, irq); + + spin_lock(&rtc->lock); + + rtc->data->clear_isr(rtc); + val = rtc->data->read_rtc_reg(rtc, reg_irq); + /* disable all the interrupts for alarm*/ + rtc_delayed_write(0, rtc, reg_irq); + /* Ack the event */ + rtc_delayed_write(1 << rtc->data->alarm, rtc, RTC_STATUS); + + spin_unlock(&rtc->lock); + + if (val & RTC_IRQ_FREQ_EN) { + if (val & RTC_IRQ_FREQ_1HZ) + event |= RTC_UF; + else + event |= RTC_PF; + } + + rtc_update_irq(rtc->rtc_dev, 1, event); + + return IRQ_HANDLED; +} + +/* + * The information given in the Armada 388 functional spec is complex. + * They give two different formulas for calculating the offset value, + * but when considering "Offset" as an 8-bit signed integer, they both + * reduce down to (we shall rename "Offset" as "val" here): + * + * val = (f_ideal / f_measured - 1) / resolution where f_ideal = 32768 + * + * Converting to time, f = 1/t: + * val = (t_measured / t_ideal - 1) / resolution where t_ideal = 1/32768 + * + * => t_measured / t_ideal = val * resolution + 1 + * + * "offset" in the RTC interface is defined as: + * t = t0 * (1 + offset * 1e-9) + * where t is the desired period, t0 is the measured period with a zero + * offset, which is t_measured above. With t0 = t_measured and t = t_ideal, + * offset = (t_ideal / t_measured - 1) / 1e-9 + * + * => t_ideal / t_measured = offset * 1e-9 + 1 + * + * so: + * + * offset * 1e-9 + 1 = 1 / (val * resolution + 1) + * + * We want "resolution" to be an integer, so resolution = R * 1e-9, giving + * offset = 1e18 / (val * R + 1e9) - 1e9 + * val = (1e18 / (offset + 1e9) - 1e9) / R + * with a common transformation: + * f(x) = 1e18 / (x + 1e9) - 1e9 + * offset = f(val * R) + * val = f(offset) / R + * + * Armada 38x supports two modes, fine mode (954ppb) and coarse mode (3815ppb). + */ +static long armada38x_ppb_convert(long ppb) +{ + long div = ppb + 1000000000L; + + return div_s64(1000000000000000000LL + div / 2, div) - 1000000000L; +} + +static int armada38x_rtc_read_offset(struct device *dev, long *offset) +{ + struct armada38x_rtc *rtc = dev_get_drvdata(dev); + unsigned long ccr, flags; + long ppb_cor; + + spin_lock_irqsave(&rtc->lock, flags); + ccr = rtc->data->read_rtc_reg(rtc, RTC_CCR); + spin_unlock_irqrestore(&rtc->lock, flags); + + ppb_cor = (ccr & RTC_CCR_MODE ? 3815 : 954) * (s8)ccr; + /* ppb_cor + 1000000000L can never be zero */ + *offset = armada38x_ppb_convert(ppb_cor); + + return 0; +} + +static int armada38x_rtc_set_offset(struct device *dev, long offset) +{ + struct armada38x_rtc *rtc = dev_get_drvdata(dev); + unsigned long ccr = 0; + long ppb_cor, off; + + /* + * The maximum ppb_cor is -128 * 3815 .. 127 * 3815, but we + * need to clamp the input. This equates to -484270 .. 488558. + * Not only is this to stop out of range "off" but also to + * avoid the division by zero in armada38x_ppb_convert(). + */ + offset = clamp(offset, -484270L, 488558L); + + ppb_cor = armada38x_ppb_convert(offset); + + /* + * Use low update mode where possible, which gives a better + * resolution of correction. + */ + off = DIV_ROUND_CLOSEST(ppb_cor, 954); + if (off > 127 || off < -128) { + ccr = RTC_CCR_MODE; + off = DIV_ROUND_CLOSEST(ppb_cor, 3815); + } + + /* + * Armada 388 requires a bit pattern in bits 14..8 depending on + * the sign bit: { 0, ~S, S, S, S, S, S } + */ + ccr |= (off & 0x3fff) ^ 0x2000; + rtc_delayed_write(ccr, rtc, RTC_CCR); + + return 0; +} + +static const struct rtc_class_ops armada38x_rtc_ops = { + .read_time = armada38x_rtc_read_time, + .set_time = armada38x_rtc_set_time, + .read_alarm = armada38x_rtc_read_alarm, + .set_alarm = armada38x_rtc_set_alarm, + .alarm_irq_enable = armada38x_rtc_alarm_irq_enable, + .read_offset = armada38x_rtc_read_offset, + .set_offset = armada38x_rtc_set_offset, +}; + +static const struct armada38x_rtc_data armada38x_data = { + .update_mbus_timing = rtc_update_38x_mbus_timing_params, + .read_rtc_reg = read_rtc_register_38x_wa, + .clear_isr = armada38x_clear_isr, + .unmask_interrupt = armada38x_unmask_interrupt, + .alarm = ALARM1, +}; + +static const struct armada38x_rtc_data armada8k_data = { + .update_mbus_timing = rtc_update_8k_mbus_timing_params, + .read_rtc_reg = read_rtc_register, + .clear_isr = armada8k_clear_isr, + .unmask_interrupt = armada8k_unmask_interrupt, + .alarm = ALARM2, +}; + +#ifdef CONFIG_OF +static const struct of_device_id armada38x_rtc_of_match_table[] = { + { + .compatible = "marvell,armada-380-rtc", + .data = &armada38x_data, + }, + { + .compatible = "marvell,armada-8k-rtc", + .data = &armada8k_data, + }, + {} +}; +MODULE_DEVICE_TABLE(of, armada38x_rtc_of_match_table); +#endif + +static __init int armada38x_rtc_probe(struct platform_device *pdev) +{ + struct resource *res; + struct armada38x_rtc *rtc; + + rtc = devm_kzalloc(&pdev->dev, sizeof(struct armada38x_rtc), + GFP_KERNEL); + if (!rtc) + return -ENOMEM; + + rtc->data = of_device_get_match_data(&pdev->dev); + + rtc->val_to_freq = devm_kcalloc(&pdev->dev, SAMPLE_NR, + sizeof(struct value_to_freq), GFP_KERNEL); + if (!rtc->val_to_freq) + return -ENOMEM; + + spin_lock_init(&rtc->lock); + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rtc"); + rtc->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(rtc->regs)) + return PTR_ERR(rtc->regs); + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rtc-soc"); + rtc->regs_soc = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(rtc->regs_soc)) + return PTR_ERR(rtc->regs_soc); + + rtc->irq = platform_get_irq(pdev, 0); + if (rtc->irq < 0) + return rtc->irq; + + rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc->rtc_dev)) + return PTR_ERR(rtc->rtc_dev); + + if (devm_request_irq(&pdev->dev, rtc->irq, armada38x_rtc_alarm_irq, + 0, pdev->name, rtc) < 0) { + dev_warn(&pdev->dev, "Interrupt not available.\n"); + rtc->irq = -1; + } + platform_set_drvdata(pdev, rtc); + + if (rtc->irq != -1) + device_init_wakeup(&pdev->dev, 1); + else + clear_bit(RTC_FEATURE_ALARM, rtc->rtc_dev->features); + + /* Update RTC-MBUS bridge timing parameters */ + rtc->data->update_mbus_timing(rtc); + + rtc->rtc_dev->ops = &armada38x_rtc_ops; + rtc->rtc_dev->range_max = U32_MAX; + + return devm_rtc_register_device(rtc->rtc_dev); +} + +#ifdef CONFIG_PM_SLEEP +static int armada38x_rtc_suspend(struct device *dev) +{ + if (device_may_wakeup(dev)) { + struct armada38x_rtc *rtc = dev_get_drvdata(dev); + + return enable_irq_wake(rtc->irq); + } + + return 0; +} + +static int armada38x_rtc_resume(struct device *dev) +{ + if (device_may_wakeup(dev)) { + struct armada38x_rtc *rtc = dev_get_drvdata(dev); + + /* Update RTC-MBUS bridge timing parameters */ + rtc->data->update_mbus_timing(rtc); + + return disable_irq_wake(rtc->irq); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(armada38x_rtc_pm_ops, + armada38x_rtc_suspend, armada38x_rtc_resume); + +static struct platform_driver armada38x_rtc_driver = { + .driver = { + .name = "armada38x-rtc", + .pm = &armada38x_rtc_pm_ops, + .of_match_table = of_match_ptr(armada38x_rtc_of_match_table), + }, +}; + +module_platform_driver_probe(armada38x_rtc_driver, armada38x_rtc_probe); + +MODULE_DESCRIPTION("Marvell Armada 38x RTC driver"); +MODULE_AUTHOR("Gregory CLEMENT "); +MODULE_LICENSE("GPL"); -- cgit v1.2.3