1 // SPDX-License-Identifier: GPL-2.0+ 2 // 3 // Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved. 4 5 #include <linux/io.h> 6 #include <linux/rtc.h> 7 #include <linux/module.h> 8 #include <linux/slab.h> 9 #include <linux/interrupt.h> 10 #include <linux/platform_device.h> 11 #include <linux/pm_wakeirq.h> 12 #include <linux/clk.h> 13 #include <linux/of.h> 14 15 #define RTC_INPUT_CLK_32768HZ (0x00 << 5) 16 #define RTC_INPUT_CLK_32000HZ (0x01 << 5) 17 #define RTC_INPUT_CLK_38400HZ (0x02 << 5) 18 19 #define RTC_SW_BIT (1 << 0) 20 #define RTC_ALM_BIT (1 << 2) 21 #define RTC_1HZ_BIT (1 << 4) 22 #define RTC_2HZ_BIT (1 << 7) 23 #define RTC_SAM0_BIT (1 << 8) 24 #define RTC_SAM1_BIT (1 << 9) 25 #define RTC_SAM2_BIT (1 << 10) 26 #define RTC_SAM3_BIT (1 << 11) 27 #define RTC_SAM4_BIT (1 << 12) 28 #define RTC_SAM5_BIT (1 << 13) 29 #define RTC_SAM6_BIT (1 << 14) 30 #define RTC_SAM7_BIT (1 << 15) 31 #define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \ 32 RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \ 33 RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT) 34 35 #define RTC_ENABLE_BIT (1 << 7) 36 37 #define MAX_PIE_NUM 9 38 #define MAX_PIE_FREQ 512 39 40 #define MXC_RTC_TIME 0 41 #define MXC_RTC_ALARM 1 42 43 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */ 44 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */ 45 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */ 46 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */ 47 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */ 48 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */ 49 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */ 50 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */ 51 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */ 52 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */ 53 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */ 54 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */ 55 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */ 56 57 enum imx_rtc_type { 58 IMX1_RTC, 59 IMX21_RTC, 60 }; 61 62 struct rtc_plat_data { 63 struct rtc_device *rtc; 64 void __iomem *ioaddr; 65 int irq; 66 struct clk *clk_ref; 67 struct clk *clk_ipg; 68 struct rtc_time g_rtc_alarm; 69 enum imx_rtc_type devtype; 70 }; 71 72 static const struct of_device_id imx_rtc_dt_ids[] = { 73 { .compatible = "fsl,imx1-rtc", .data = (const void *)IMX1_RTC }, 74 { .compatible = "fsl,imx21-rtc", .data = (const void *)IMX21_RTC }, 75 {} 76 }; 77 MODULE_DEVICE_TABLE(of, imx_rtc_dt_ids); 78 79 static inline int is_imx1_rtc(struct rtc_plat_data *data) 80 { 81 return data->devtype == IMX1_RTC; 82 } 83 84 /* 85 * This function is used to obtain the RTC time or the alarm value in 86 * second. 87 */ 88 static time64_t get_alarm_or_time(struct device *dev, int time_alarm) 89 { 90 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 91 void __iomem *ioaddr = pdata->ioaddr; 92 u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0; 93 94 switch (time_alarm) { 95 case MXC_RTC_TIME: 96 day = readw(ioaddr + RTC_DAYR); 97 hr_min = readw(ioaddr + RTC_HOURMIN); 98 sec = readw(ioaddr + RTC_SECOND); 99 break; 100 case MXC_RTC_ALARM: 101 day = readw(ioaddr + RTC_DAYALARM); 102 hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff; 103 sec = readw(ioaddr + RTC_ALRM_SEC); 104 break; 105 } 106 107 hr = hr_min >> 8; 108 min = hr_min & 0xff; 109 110 return ((((time64_t)day * 24 + hr) * 60) + min) * 60 + sec; 111 } 112 113 /* 114 * This function sets the RTC alarm value or the time value. 115 */ 116 static void set_alarm_or_time(struct device *dev, int time_alarm, time64_t time) 117 { 118 u32 tod, day, hr, min, sec, temp; 119 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 120 void __iomem *ioaddr = pdata->ioaddr; 121 122 day = div_s64_rem(time, 86400, &tod); 123 124 /* time is within a day now */ 125 hr = tod / 3600; 126 tod -= hr * 3600; 127 128 /* time is within an hour now */ 129 min = tod / 60; 130 sec = tod - min * 60; 131 132 temp = (hr << 8) + min; 133 134 switch (time_alarm) { 135 case MXC_RTC_TIME: 136 writew(day, ioaddr + RTC_DAYR); 137 writew(sec, ioaddr + RTC_SECOND); 138 writew(temp, ioaddr + RTC_HOURMIN); 139 break; 140 case MXC_RTC_ALARM: 141 writew(day, ioaddr + RTC_DAYALARM); 142 writew(sec, ioaddr + RTC_ALRM_SEC); 143 writew(temp, ioaddr + RTC_ALRM_HM); 144 break; 145 } 146 } 147 148 /* 149 * This function updates the RTC alarm registers and then clears all the 150 * interrupt status bits. 151 */ 152 static void rtc_update_alarm(struct device *dev, struct rtc_time *alrm) 153 { 154 time64_t time; 155 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 156 void __iomem *ioaddr = pdata->ioaddr; 157 158 time = rtc_tm_to_time64(alrm); 159 160 /* clear all the interrupt status bits */ 161 writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR); 162 set_alarm_or_time(dev, MXC_RTC_ALARM, time); 163 } 164 165 static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit, 166 unsigned int enabled) 167 { 168 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 169 void __iomem *ioaddr = pdata->ioaddr; 170 u32 reg; 171 unsigned long flags; 172 173 spin_lock_irqsave(&pdata->rtc->irq_lock, flags); 174 reg = readw(ioaddr + RTC_RTCIENR); 175 176 if (enabled) 177 reg |= bit; 178 else 179 reg &= ~bit; 180 181 writew(reg, ioaddr + RTC_RTCIENR); 182 spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags); 183 } 184 185 /* This function is the RTC interrupt service routine. */ 186 static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id) 187 { 188 struct platform_device *pdev = dev_id; 189 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 190 void __iomem *ioaddr = pdata->ioaddr; 191 u32 status; 192 u32 events = 0; 193 194 spin_lock(&pdata->rtc->irq_lock); 195 status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR); 196 /* clear interrupt sources */ 197 writew(status, ioaddr + RTC_RTCISR); 198 199 /* update irq data & counter */ 200 if (status & RTC_ALM_BIT) { 201 events |= (RTC_AF | RTC_IRQF); 202 /* RTC alarm should be one-shot */ 203 mxc_rtc_irq_enable(&pdev->dev, RTC_ALM_BIT, 0); 204 } 205 206 if (status & PIT_ALL_ON) 207 events |= (RTC_PF | RTC_IRQF); 208 209 rtc_update_irq(pdata->rtc, 1, events); 210 spin_unlock(&pdata->rtc->irq_lock); 211 212 return IRQ_HANDLED; 213 } 214 215 static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 216 { 217 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled); 218 return 0; 219 } 220 221 /* 222 * This function reads the current RTC time into tm in Gregorian date. 223 */ 224 static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm) 225 { 226 time64_t val; 227 228 /* Avoid roll-over from reading the different registers */ 229 do { 230 val = get_alarm_or_time(dev, MXC_RTC_TIME); 231 } while (val != get_alarm_or_time(dev, MXC_RTC_TIME)); 232 233 rtc_time64_to_tm(val, tm); 234 235 return 0; 236 } 237 238 /* 239 * This function sets the internal RTC time based on tm in Gregorian date. 240 */ 241 static int mxc_rtc_set_time(struct device *dev, struct rtc_time *tm) 242 { 243 time64_t time = rtc_tm_to_time64(tm); 244 245 /* Avoid roll-over from reading the different registers */ 246 do { 247 set_alarm_or_time(dev, MXC_RTC_TIME, time); 248 } while (time != get_alarm_or_time(dev, MXC_RTC_TIME)); 249 250 return 0; 251 } 252 253 /* 254 * This function reads the current alarm value into the passed in 'alrm' 255 * argument. It updates the alrm's pending field value based on the whether 256 * an alarm interrupt occurs or not. 257 */ 258 static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 259 { 260 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 261 void __iomem *ioaddr = pdata->ioaddr; 262 263 rtc_time64_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time); 264 alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0; 265 266 return 0; 267 } 268 269 /* 270 * This function sets the RTC alarm based on passed in alrm. 271 */ 272 static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 273 { 274 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 275 276 rtc_update_alarm(dev, &alrm->time); 277 278 memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time)); 279 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled); 280 281 return 0; 282 } 283 284 /* RTC layer */ 285 static const struct rtc_class_ops mxc_rtc_ops = { 286 .read_time = mxc_rtc_read_time, 287 .set_time = mxc_rtc_set_time, 288 .read_alarm = mxc_rtc_read_alarm, 289 .set_alarm = mxc_rtc_set_alarm, 290 .alarm_irq_enable = mxc_rtc_alarm_irq_enable, 291 }; 292 293 static int mxc_rtc_probe(struct platform_device *pdev) 294 { 295 struct rtc_device *rtc; 296 struct rtc_plat_data *pdata = NULL; 297 u32 reg; 298 unsigned long rate; 299 int ret; 300 301 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 302 if (!pdata) 303 return -ENOMEM; 304 305 pdata->devtype = (uintptr_t)of_device_get_match_data(&pdev->dev); 306 307 pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0); 308 if (IS_ERR(pdata->ioaddr)) 309 return PTR_ERR(pdata->ioaddr); 310 311 rtc = devm_rtc_allocate_device(&pdev->dev); 312 if (IS_ERR(rtc)) 313 return PTR_ERR(rtc); 314 315 pdata->rtc = rtc; 316 rtc->ops = &mxc_rtc_ops; 317 if (is_imx1_rtc(pdata)) { 318 struct rtc_time tm; 319 320 /* 9bit days + hours minutes seconds */ 321 rtc->range_max = (1 << 9) * 86400 - 1; 322 323 /* 324 * Set the start date as beginning of the current year. This can 325 * be overridden using device tree. 326 */ 327 rtc_time64_to_tm(ktime_get_real_seconds(), &tm); 328 rtc->start_secs = mktime64(tm.tm_year, 1, 1, 0, 0, 0); 329 rtc->set_start_time = true; 330 } else { 331 /* 16bit days + hours minutes seconds */ 332 rtc->range_max = (1 << 16) * 86400ULL - 1; 333 } 334 335 pdata->clk_ipg = devm_clk_get_enabled(&pdev->dev, "ipg"); 336 if (IS_ERR(pdata->clk_ipg)) { 337 dev_err(&pdev->dev, "unable to get ipg clock!\n"); 338 return PTR_ERR(pdata->clk_ipg); 339 } 340 341 pdata->clk_ref = devm_clk_get_enabled(&pdev->dev, "ref"); 342 if (IS_ERR(pdata->clk_ref)) { 343 dev_err(&pdev->dev, "unable to get ref clock!\n"); 344 return PTR_ERR(pdata->clk_ref); 345 } 346 347 rate = clk_get_rate(pdata->clk_ref); 348 349 if (rate == 32768) 350 reg = RTC_INPUT_CLK_32768HZ; 351 else if (rate == 32000) 352 reg = RTC_INPUT_CLK_32000HZ; 353 else if (rate == 38400) 354 reg = RTC_INPUT_CLK_38400HZ; 355 else { 356 dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate); 357 return -EINVAL; 358 } 359 360 reg |= RTC_ENABLE_BIT; 361 writew(reg, (pdata->ioaddr + RTC_RTCCTL)); 362 if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) { 363 dev_err(&pdev->dev, "hardware module can't be enabled!\n"); 364 return -EIO; 365 } 366 367 platform_set_drvdata(pdev, pdata); 368 369 /* Configure and enable the RTC */ 370 pdata->irq = platform_get_irq(pdev, 0); 371 372 if (pdata->irq >= 0 && 373 devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt, 374 IRQF_SHARED, pdev->name, pdev) < 0) { 375 dev_warn(&pdev->dev, "interrupt not available.\n"); 376 pdata->irq = -1; 377 } 378 379 if (pdata->irq >= 0) { 380 device_init_wakeup(&pdev->dev, 1); 381 ret = dev_pm_set_wake_irq(&pdev->dev, pdata->irq); 382 if (ret) 383 dev_err(&pdev->dev, "failed to enable irq wake\n"); 384 } 385 386 ret = devm_rtc_register_device(rtc); 387 388 return ret; 389 } 390 391 static struct platform_driver mxc_rtc_driver = { 392 .driver = { 393 .name = "mxc_rtc", 394 .of_match_table = imx_rtc_dt_ids, 395 }, 396 .probe = mxc_rtc_probe, 397 }; 398 399 module_platform_driver(mxc_rtc_driver) 400 401 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); 402 MODULE_DESCRIPTION("RTC driver for Freescale MXC"); 403 MODULE_LICENSE("GPL"); 404 405