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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Loongson RTC driver4 *5 * Maintained out-of-tree by Huacai Chen <chenhuacai@kernel.org>.6 * Rewritten for mainline by WANG Xuerui <git@xen0n.name>.7 * Binbin Zhou <zhoubinbin@loongson.cn>8 */9 10#include <linux/bitfield.h>11#include <linux/kernel.h>12#include <linux/module.h>13#include <linux/platform_device.h>14#include <linux/regmap.h>15#include <linux/rtc.h>16#include <linux/acpi.h>17 18/* Time Of Year(TOY) counters registers */19#define TOY_TRIM_REG 0x20 /* Must be initialized to 0 */20#define TOY_WRITE0_REG 0x24 /* TOY low 32-bits value (write-only) */21#define TOY_WRITE1_REG 0x28 /* TOY high 32-bits value (write-only) */22#define TOY_READ0_REG 0x2c /* TOY low 32-bits value (read-only) */23#define TOY_READ1_REG 0x30 /* TOY high 32-bits value (read-only) */24#define TOY_MATCH0_REG 0x34 /* TOY timing interrupt 0 */25#define TOY_MATCH1_REG 0x38 /* TOY timing interrupt 1 */26#define TOY_MATCH2_REG 0x3c /* TOY timing interrupt 2 */27 28/* RTC counters registers */29#define RTC_CTRL_REG 0x40 /* TOY and RTC control register */30#define RTC_TRIM_REG 0x60 /* Must be initialized to 0 */31#define RTC_WRITE0_REG 0x64 /* RTC counters value (write-only) */32#define RTC_READ0_REG 0x68 /* RTC counters value (read-only) */33#define RTC_MATCH0_REG 0x6c /* RTC timing interrupt 0 */34#define RTC_MATCH1_REG 0x70 /* RTC timing interrupt 1 */35#define RTC_MATCH2_REG 0x74 /* RTC timing interrupt 2 */36 37/* bitmask of TOY_WRITE0_REG */38#define TOY_MON GENMASK(31, 26)39#define TOY_DAY GENMASK(25, 21)40#define TOY_HOUR GENMASK(20, 16)41#define TOY_MIN GENMASK(15, 10)42#define TOY_SEC GENMASK(9, 4)43#define TOY_MSEC GENMASK(3, 0)44 45/* bitmask of TOY_MATCH0/1/2_REG */46#define TOY_MATCH_YEAR GENMASK(31, 26)47#define TOY_MATCH_MON GENMASK(25, 22)48#define TOY_MATCH_DAY GENMASK(21, 17)49#define TOY_MATCH_HOUR GENMASK(16, 12)50#define TOY_MATCH_MIN GENMASK(11, 6)51#define TOY_MATCH_SEC GENMASK(5, 0)52 53/* bitmask of RTC_CTRL_REG */54#define RTC_ENABLE BIT(13) /* 1: RTC counters enable */55#define TOY_ENABLE BIT(11) /* 1: TOY counters enable */56#define OSC_ENABLE BIT(8) /* 1: 32.768k crystal enable */57#define TOY_ENABLE_MASK (TOY_ENABLE | OSC_ENABLE)58 59/* PM domain registers */60#define PM1_STS_REG 0x0c /* Power management 1 status register */61#define RTC_STS BIT(10) /* RTC status */62#define PM1_EN_REG 0x10 /* Power management 1 enable register */63#define RTC_EN BIT(10) /* RTC event enable */64 65/*66 * According to the LS1C manual, RTC_CTRL and alarm-related registers are not defined.67 * Accessing the relevant registers will cause the system to hang.68 */69#define LS1C_RTC_CTRL_WORKAROUND BIT(0)70 71struct loongson_rtc_config {72 u32 pm_offset; /* Offset of PM domain, for RTC alarm wakeup */73 u32 flags; /* Workaround bits */74};75 76struct loongson_rtc_priv {77 spinlock_t lock; /* protects PM registers access */78 u32 fix_year; /* RTC alarm year compensation value */79 struct rtc_device *rtcdev;80 struct regmap *regmap;81 void __iomem *pm_base; /* PM domain base, for RTC alarm wakeup */82 const struct loongson_rtc_config *config;83};84 85static const struct loongson_rtc_config ls1b_rtc_config = {86 .pm_offset = 0,87 .flags = 0,88};89 90static const struct loongson_rtc_config ls1c_rtc_config = {91 .pm_offset = 0,92 .flags = LS1C_RTC_CTRL_WORKAROUND,93};94 95static const struct loongson_rtc_config generic_rtc_config = {96 .pm_offset = 0x100,97 .flags = 0,98};99 100static const struct loongson_rtc_config ls2k1000_rtc_config = {101 .pm_offset = 0x800,102 .flags = 0,103};104 105static const struct regmap_config loongson_rtc_regmap_config = {106 .reg_bits = 32,107 .val_bits = 32,108 .reg_stride = 4,109};110 111/* RTC alarm irq handler */112static irqreturn_t loongson_rtc_isr(int irq, void *id)113{114 struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id;115 116 rtc_update_irq(priv->rtcdev, 1, RTC_AF | RTC_IRQF);117 return IRQ_HANDLED;118}119 120/* For ACPI fixed event handler */121static u32 loongson_rtc_handler(void *id)122{123 struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id;124 125 spin_lock(&priv->lock);126 /* Disable RTC alarm wakeup and interrupt */127 writel(readl(priv->pm_base + PM1_EN_REG) & ~RTC_EN,128 priv->pm_base + PM1_EN_REG);129 130 /* Clear RTC interrupt status */131 writel(RTC_STS, priv->pm_base + PM1_STS_REG);132 spin_unlock(&priv->lock);133 134 /*135 * The TOY_MATCH0_REG should be cleared 0 here,136 * otherwise the interrupt cannot be cleared.137 */138 return regmap_write(priv->regmap, TOY_MATCH0_REG, 0);139}140 141static int loongson_rtc_set_enabled(struct device *dev)142{143 struct loongson_rtc_priv *priv = dev_get_drvdata(dev);144 145 if (priv->config->flags & LS1C_RTC_CTRL_WORKAROUND)146 return 0;147 148 /* Enable RTC TOY counters and crystal */149 return regmap_update_bits(priv->regmap, RTC_CTRL_REG, TOY_ENABLE_MASK,150 TOY_ENABLE_MASK);151}152 153static bool loongson_rtc_get_enabled(struct device *dev)154{155 int ret;156 u32 ctrl_data;157 struct loongson_rtc_priv *priv = dev_get_drvdata(dev);158 159 if (priv->config->flags & LS1C_RTC_CTRL_WORKAROUND)160 return true;161 162 ret = regmap_read(priv->regmap, RTC_CTRL_REG, &ctrl_data);163 if (ret < 0)164 return false;165 166 return ctrl_data & TOY_ENABLE_MASK;167}168 169static int loongson_rtc_read_time(struct device *dev, struct rtc_time *tm)170{171 int ret;172 u32 rtc_data[2];173 struct loongson_rtc_priv *priv = dev_get_drvdata(dev);174 175 if (!loongson_rtc_get_enabled(dev))176 return -EINVAL;177 178 ret = regmap_bulk_read(priv->regmap, TOY_READ0_REG, rtc_data,179 ARRAY_SIZE(rtc_data));180 if (ret < 0)181 return ret;182 183 tm->tm_sec = FIELD_GET(TOY_SEC, rtc_data[0]);184 tm->tm_min = FIELD_GET(TOY_MIN, rtc_data[0]);185 tm->tm_hour = FIELD_GET(TOY_HOUR, rtc_data[0]);186 tm->tm_mday = FIELD_GET(TOY_DAY, rtc_data[0]);187 tm->tm_mon = FIELD_GET(TOY_MON, rtc_data[0]) - 1;188 tm->tm_year = rtc_data[1];189 190 /* Prepare for RTC alarm year compensation value. */191 priv->fix_year = tm->tm_year / 64 * 64;192 return 0;193}194 195static int loongson_rtc_set_time(struct device *dev, struct rtc_time *tm)196{197 int ret;198 u32 rtc_data[2];199 struct loongson_rtc_priv *priv = dev_get_drvdata(dev);200 201 rtc_data[0] = FIELD_PREP(TOY_SEC, tm->tm_sec)202 | FIELD_PREP(TOY_MIN, tm->tm_min)203 | FIELD_PREP(TOY_HOUR, tm->tm_hour)204 | FIELD_PREP(TOY_DAY, tm->tm_mday)205 | FIELD_PREP(TOY_MON, tm->tm_mon + 1);206 rtc_data[1] = tm->tm_year;207 208 ret = regmap_bulk_write(priv->regmap, TOY_WRITE0_REG, rtc_data,209 ARRAY_SIZE(rtc_data));210 if (ret < 0)211 return ret;212 213 return loongson_rtc_set_enabled(dev);214}215 216static int loongson_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)217{218 int ret;219 u32 alarm_data;220 struct loongson_rtc_priv *priv = dev_get_drvdata(dev);221 222 ret = regmap_read(priv->regmap, TOY_MATCH0_REG, &alarm_data);223 if (ret < 0)224 return ret;225 226 alrm->time.tm_sec = FIELD_GET(TOY_MATCH_SEC, alarm_data);227 alrm->time.tm_min = FIELD_GET(TOY_MATCH_MIN, alarm_data);228 alrm->time.tm_hour = FIELD_GET(TOY_MATCH_HOUR, alarm_data);229 alrm->time.tm_mday = FIELD_GET(TOY_MATCH_DAY, alarm_data);230 alrm->time.tm_mon = FIELD_GET(TOY_MATCH_MON, alarm_data) - 1;231 /*232 * This is a hardware bug: the year field of SYS_TOYMATCH is only 6 bits,233 * making it impossible to save year values larger than 64.234 *235 * SYS_TOYMATCH is used to match the alarm time value and determine if236 * an alarm is triggered, so we must keep the lower 6 bits of the year237 * value constant during the value conversion.238 *239 * In summary, we need to manually add 64(or a multiple of 64) to the240 * year value to avoid the invalid alarm prompt at startup.241 */242 alrm->time.tm_year = FIELD_GET(TOY_MATCH_YEAR, alarm_data) + priv->fix_year;243 244 alrm->enabled = !!(readl(priv->pm_base + PM1_EN_REG) & RTC_EN);245 return 0;246}247 248static int loongson_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)249{250 u32 val;251 struct loongson_rtc_priv *priv = dev_get_drvdata(dev);252 253 spin_lock(&priv->lock);254 val = readl(priv->pm_base + PM1_EN_REG);255 /* Enable RTC alarm wakeup */256 writel(enabled ? val | RTC_EN : val & ~RTC_EN,257 priv->pm_base + PM1_EN_REG);258 spin_unlock(&priv->lock);259 260 return 0;261}262 263static int loongson_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)264{265 int ret;266 u32 alarm_data;267 struct loongson_rtc_priv *priv = dev_get_drvdata(dev);268 269 alarm_data = FIELD_PREP(TOY_MATCH_SEC, alrm->time.tm_sec)270 | FIELD_PREP(TOY_MATCH_MIN, alrm->time.tm_min)271 | FIELD_PREP(TOY_MATCH_HOUR, alrm->time.tm_hour)272 | FIELD_PREP(TOY_MATCH_DAY, alrm->time.tm_mday)273 | FIELD_PREP(TOY_MATCH_MON, alrm->time.tm_mon + 1)274 | FIELD_PREP(TOY_MATCH_YEAR, alrm->time.tm_year - priv->fix_year);275 276 ret = regmap_write(priv->regmap, TOY_MATCH0_REG, alarm_data);277 if (ret < 0)278 return ret;279 280 return loongson_rtc_alarm_irq_enable(dev, alrm->enabled);281}282 283static const struct rtc_class_ops loongson_rtc_ops = {284 .read_time = loongson_rtc_read_time,285 .set_time = loongson_rtc_set_time,286 .read_alarm = loongson_rtc_read_alarm,287 .set_alarm = loongson_rtc_set_alarm,288 .alarm_irq_enable = loongson_rtc_alarm_irq_enable,289};290 291static int loongson_rtc_probe(struct platform_device *pdev)292{293 int ret, alarm_irq;294 void __iomem *regs;295 struct loongson_rtc_priv *priv;296 struct device *dev = &pdev->dev;297 298 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);299 if (!priv)300 return -ENOMEM;301 302 regs = devm_platform_ioremap_resource(pdev, 0);303 if (IS_ERR(regs))304 return dev_err_probe(dev, PTR_ERR(regs),305 "devm_platform_ioremap_resource failed\n");306 307 priv->regmap = devm_regmap_init_mmio(dev, regs,308 &loongson_rtc_regmap_config);309 if (IS_ERR(priv->regmap))310 return dev_err_probe(dev, PTR_ERR(priv->regmap),311 "devm_regmap_init_mmio failed\n");312 313 priv->config = device_get_match_data(dev);314 spin_lock_init(&priv->lock);315 platform_set_drvdata(pdev, priv);316 317 priv->rtcdev = devm_rtc_allocate_device(dev);318 if (IS_ERR(priv->rtcdev))319 return dev_err_probe(dev, PTR_ERR(priv->rtcdev),320 "devm_rtc_allocate_device failed\n");321 322 /* Get RTC alarm irq */323 alarm_irq = platform_get_irq(pdev, 0);324 if (alarm_irq > 0) {325 ret = devm_request_irq(dev, alarm_irq, loongson_rtc_isr,326 0, "loongson-alarm", priv);327 if (ret < 0)328 return dev_err_probe(dev, ret, "Unable to request irq %d\n",329 alarm_irq);330 331 priv->pm_base = regs - priv->config->pm_offset;332 device_init_wakeup(dev, 1);333 334 if (has_acpi_companion(dev))335 acpi_install_fixed_event_handler(ACPI_EVENT_RTC,336 loongson_rtc_handler, priv);337 } else {338 /* Loongson-1C RTC does not support alarm */339 clear_bit(RTC_FEATURE_ALARM, priv->rtcdev->features);340 }341 342 /* Loongson RTC does not support UIE */343 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, priv->rtcdev->features);344 priv->rtcdev->ops = &loongson_rtc_ops;345 priv->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000;346 priv->rtcdev->range_max = RTC_TIMESTAMP_END_2099;347 348 return devm_rtc_register_device(priv->rtcdev);349}350 351static void loongson_rtc_remove(struct platform_device *pdev)352{353 struct device *dev = &pdev->dev;354 struct loongson_rtc_priv *priv = dev_get_drvdata(dev);355 356 if (!test_bit(RTC_FEATURE_ALARM, priv->rtcdev->features))357 return;358 359 if (has_acpi_companion(dev))360 acpi_remove_fixed_event_handler(ACPI_EVENT_RTC,361 loongson_rtc_handler);362 363 device_init_wakeup(dev, 0);364 loongson_rtc_alarm_irq_enable(dev, 0);365}366 367static const struct of_device_id loongson_rtc_of_match[] = {368 { .compatible = "loongson,ls1b-rtc", .data = &ls1b_rtc_config },369 { .compatible = "loongson,ls1c-rtc", .data = &ls1c_rtc_config },370 { .compatible = "loongson,ls7a-rtc", .data = &generic_rtc_config },371 { .compatible = "loongson,ls2k1000-rtc", .data = &ls2k1000_rtc_config },372 { /* sentinel */ }373};374MODULE_DEVICE_TABLE(of, loongson_rtc_of_match);375 376static const struct acpi_device_id loongson_rtc_acpi_match[] = {377 { "LOON0001", .driver_data = (kernel_ulong_t)&generic_rtc_config },378 { }379};380MODULE_DEVICE_TABLE(acpi, loongson_rtc_acpi_match);381 382static struct platform_driver loongson_rtc_driver = {383 .probe = loongson_rtc_probe,384 .remove_new = loongson_rtc_remove,385 .driver = {386 .name = "loongson-rtc",387 .of_match_table = loongson_rtc_of_match,388 .acpi_match_table = loongson_rtc_acpi_match,389 },390};391module_platform_driver(loongson_rtc_driver);392 393MODULE_DESCRIPTION("Loongson RTC driver");394MODULE_AUTHOR("Binbin Zhou <zhoubinbin@loongson.cn>");395MODULE_AUTHOR("WANG Xuerui <git@xen0n.name>");396MODULE_AUTHOR("Huacai Chen <chenhuacai@kernel.org>");397MODULE_LICENSE("GPL");398