1 /* 2 * Copyright (C) 2016 Oleksij Rempel <linux@rempel-privat.de> 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License as published by the 6 * Free Software Foundation; either version 2 of the License, 7 * or (at your option) any later version. 8 */ 9 10 #include <linux/clk.h> 11 #include <linux/interrupt.h> 12 #include <linux/io.h> 13 #include <linux/module.h> 14 #include <linux/of.h> 15 #include <linux/platform_device.h> 16 #include <linux/rtc.h> 17 18 /* Miscellaneous registers */ 19 /* Interrupt Location Register */ 20 #define HW_ILR 0x00 21 #define BM_RTCALF BIT(1) 22 #define BM_RTCCIF BIT(0) 23 24 /* Clock Control Register */ 25 #define HW_CCR 0x08 26 /* Calibration counter disable */ 27 #define BM_CCALOFF BIT(4) 28 /* Reset internal oscillator divider */ 29 #define BM_CTCRST BIT(1) 30 /* Clock Enable */ 31 #define BM_CLKEN BIT(0) 32 33 /* Counter Increment Interrupt Register */ 34 #define HW_CIIR 0x0C 35 #define BM_CIIR_IMYEAR BIT(7) 36 #define BM_CIIR_IMMON BIT(6) 37 #define BM_CIIR_IMDOY BIT(5) 38 #define BM_CIIR_IMDOW BIT(4) 39 #define BM_CIIR_IMDOM BIT(3) 40 #define BM_CIIR_IMHOUR BIT(2) 41 #define BM_CIIR_IMMIN BIT(1) 42 #define BM_CIIR_IMSEC BIT(0) 43 44 /* Alarm Mask Register */ 45 #define HW_AMR 0x10 46 #define BM_AMR_IMYEAR BIT(7) 47 #define BM_AMR_IMMON BIT(6) 48 #define BM_AMR_IMDOY BIT(5) 49 #define BM_AMR_IMDOW BIT(4) 50 #define BM_AMR_IMDOM BIT(3) 51 #define BM_AMR_IMHOUR BIT(2) 52 #define BM_AMR_IMMIN BIT(1) 53 #define BM_AMR_IMSEC BIT(0) 54 #define BM_AMR_OFF 0xff 55 56 /* Consolidated time registers */ 57 #define HW_CTIME0 0x14 58 #define BM_CTIME0_DOW_S 24 59 #define BM_CTIME0_DOW_M 0x7 60 #define BM_CTIME0_HOUR_S 16 61 #define BM_CTIME0_HOUR_M 0x1f 62 #define BM_CTIME0_MIN_S 8 63 #define BM_CTIME0_MIN_M 0x3f 64 #define BM_CTIME0_SEC_S 0 65 #define BM_CTIME0_SEC_M 0x3f 66 67 #define HW_CTIME1 0x18 68 #define BM_CTIME1_YEAR_S 16 69 #define BM_CTIME1_YEAR_M 0xfff 70 #define BM_CTIME1_MON_S 8 71 #define BM_CTIME1_MON_M 0xf 72 #define BM_CTIME1_DOM_S 0 73 #define BM_CTIME1_DOM_M 0x1f 74 75 #define HW_CTIME2 0x1C 76 #define BM_CTIME2_DOY_S 0 77 #define BM_CTIME2_DOY_M 0xfff 78 79 /* Time counter registers */ 80 #define HW_SEC 0x20 81 #define HW_MIN 0x24 82 #define HW_HOUR 0x28 83 #define HW_DOM 0x2C 84 #define HW_DOW 0x30 85 #define HW_DOY 0x34 86 #define HW_MONTH 0x38 87 #define HW_YEAR 0x3C 88 89 #define HW_CALIBRATION 0x40 90 #define BM_CALDIR_BACK BIT(17) 91 #define BM_CALVAL_M 0x1ffff 92 93 /* General purpose registers */ 94 #define HW_GPREG0 0x44 95 #define HW_GPREG1 0x48 96 #define HW_GPREG2 0x4C 97 #define HW_GPREG3 0x50 98 #define HW_GPREG4 0x54 99 100 /* Alarm register group */ 101 #define HW_ALSEC 0x60 102 #define HW_ALMIN 0x64 103 #define HW_ALHOUR 0x68 104 #define HW_ALDOM 0x6C 105 #define HW_ALDOW 0x70 106 #define HW_ALDOY 0x74 107 #define HW_ALMON 0x78 108 #define HW_ALYEAR 0x7C 109 110 struct asm9260_rtc_priv { 111 struct device *dev; 112 void __iomem *iobase; 113 struct rtc_device *rtc; 114 struct clk *clk; 115 /* io lock */ 116 spinlock_t lock; 117 }; 118 119 static irqreturn_t asm9260_rtc_irq(int irq, void *dev_id) 120 { 121 struct asm9260_rtc_priv *priv = dev_id; 122 u32 isr; 123 unsigned long events = 0; 124 125 isr = ioread32(priv->iobase + HW_CIIR); 126 if (!isr) 127 return IRQ_NONE; 128 129 iowrite32(0, priv->iobase + HW_CIIR); 130 131 events |= RTC_AF | RTC_IRQF; 132 133 rtc_update_irq(priv->rtc, 1, events); 134 135 return IRQ_HANDLED; 136 } 137 138 static int asm9260_rtc_read_time(struct device *dev, struct rtc_time *tm) 139 { 140 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); 141 u32 ctime0, ctime1, ctime2; 142 unsigned long irq_flags; 143 144 spin_lock_irqsave(&priv->lock, irq_flags); 145 ctime0 = ioread32(priv->iobase + HW_CTIME0); 146 ctime1 = ioread32(priv->iobase + HW_CTIME1); 147 ctime2 = ioread32(priv->iobase + HW_CTIME2); 148 149 if (ctime1 != ioread32(priv->iobase + HW_CTIME1)) { 150 /* 151 * woops, counter flipped right now. Now we are safe 152 * to reread. 153 */ 154 ctime0 = ioread32(priv->iobase + HW_CTIME0); 155 ctime1 = ioread32(priv->iobase + HW_CTIME1); 156 ctime2 = ioread32(priv->iobase + HW_CTIME2); 157 } 158 spin_unlock_irqrestore(&priv->lock, irq_flags); 159 160 tm->tm_sec = (ctime0 >> BM_CTIME0_SEC_S) & BM_CTIME0_SEC_M; 161 tm->tm_min = (ctime0 >> BM_CTIME0_MIN_S) & BM_CTIME0_MIN_M; 162 tm->tm_hour = (ctime0 >> BM_CTIME0_HOUR_S) & BM_CTIME0_HOUR_M; 163 tm->tm_wday = (ctime0 >> BM_CTIME0_DOW_S) & BM_CTIME0_DOW_M; 164 165 tm->tm_mday = (ctime1 >> BM_CTIME1_DOM_S) & BM_CTIME1_DOM_M; 166 tm->tm_mon = (ctime1 >> BM_CTIME1_MON_S) & BM_CTIME1_MON_M; 167 tm->tm_year = (ctime1 >> BM_CTIME1_YEAR_S) & BM_CTIME1_YEAR_M; 168 169 tm->tm_yday = (ctime2 >> BM_CTIME2_DOY_S) & BM_CTIME2_DOY_M; 170 171 return 0; 172 } 173 174 static int asm9260_rtc_set_time(struct device *dev, struct rtc_time *tm) 175 { 176 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); 177 unsigned long irq_flags; 178 179 spin_lock_irqsave(&priv->lock, irq_flags); 180 /* 181 * make sure SEC counter will not flip other counter on write time, 182 * real value will be written at the enf of sequence. 183 */ 184 iowrite32(0, priv->iobase + HW_SEC); 185 186 iowrite32(tm->tm_year, priv->iobase + HW_YEAR); 187 iowrite32(tm->tm_mon, priv->iobase + HW_MONTH); 188 iowrite32(tm->tm_mday, priv->iobase + HW_DOM); 189 iowrite32(tm->tm_wday, priv->iobase + HW_DOW); 190 iowrite32(tm->tm_yday, priv->iobase + HW_DOY); 191 iowrite32(tm->tm_hour, priv->iobase + HW_HOUR); 192 iowrite32(tm->tm_min, priv->iobase + HW_MIN); 193 iowrite32(tm->tm_sec, priv->iobase + HW_SEC); 194 spin_unlock_irqrestore(&priv->lock, irq_flags); 195 196 return 0; 197 } 198 199 static int asm9260_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 200 { 201 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); 202 unsigned long irq_flags; 203 204 spin_lock_irqsave(&priv->lock, irq_flags); 205 alrm->time.tm_year = ioread32(priv->iobase + HW_ALYEAR); 206 alrm->time.tm_mon = ioread32(priv->iobase + HW_ALMON); 207 alrm->time.tm_mday = ioread32(priv->iobase + HW_ALDOM); 208 alrm->time.tm_wday = ioread32(priv->iobase + HW_ALDOW); 209 alrm->time.tm_yday = ioread32(priv->iobase + HW_ALDOY); 210 alrm->time.tm_hour = ioread32(priv->iobase + HW_ALHOUR); 211 alrm->time.tm_min = ioread32(priv->iobase + HW_ALMIN); 212 alrm->time.tm_sec = ioread32(priv->iobase + HW_ALSEC); 213 214 alrm->enabled = ioread32(priv->iobase + HW_AMR) ? 1 : 0; 215 alrm->pending = ioread32(priv->iobase + HW_CIIR) ? 1 : 0; 216 spin_unlock_irqrestore(&priv->lock, irq_flags); 217 218 return rtc_valid_tm(&alrm->time); 219 } 220 221 static int asm9260_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 222 { 223 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); 224 unsigned long irq_flags; 225 226 spin_lock_irqsave(&priv->lock, irq_flags); 227 iowrite32(alrm->time.tm_year, priv->iobase + HW_ALYEAR); 228 iowrite32(alrm->time.tm_mon, priv->iobase + HW_ALMON); 229 iowrite32(alrm->time.tm_mday, priv->iobase + HW_ALDOM); 230 iowrite32(alrm->time.tm_wday, priv->iobase + HW_ALDOW); 231 iowrite32(alrm->time.tm_yday, priv->iobase + HW_ALDOY); 232 iowrite32(alrm->time.tm_hour, priv->iobase + HW_ALHOUR); 233 iowrite32(alrm->time.tm_min, priv->iobase + HW_ALMIN); 234 iowrite32(alrm->time.tm_sec, priv->iobase + HW_ALSEC); 235 236 iowrite32(alrm->enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR); 237 spin_unlock_irqrestore(&priv->lock, irq_flags); 238 239 return 0; 240 } 241 242 static int asm9260_alarm_irq_enable(struct device *dev, unsigned int enabled) 243 { 244 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); 245 246 iowrite32(enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR); 247 return 0; 248 } 249 250 static const struct rtc_class_ops asm9260_rtc_ops = { 251 .read_time = asm9260_rtc_read_time, 252 .set_time = asm9260_rtc_set_time, 253 .read_alarm = asm9260_rtc_read_alarm, 254 .set_alarm = asm9260_rtc_set_alarm, 255 .alarm_irq_enable = asm9260_alarm_irq_enable, 256 }; 257 258 static int asm9260_rtc_probe(struct platform_device *pdev) 259 { 260 struct asm9260_rtc_priv *priv; 261 struct device *dev = &pdev->dev; 262 struct resource *res; 263 int irq_alarm, ret; 264 u32 ccr; 265 266 priv = devm_kzalloc(dev, sizeof(struct asm9260_rtc_priv), GFP_KERNEL); 267 if (!priv) 268 return -ENOMEM; 269 270 priv->dev = &pdev->dev; 271 platform_set_drvdata(pdev, priv); 272 273 irq_alarm = platform_get_irq(pdev, 0); 274 if (irq_alarm < 0) { 275 dev_err(dev, "No alarm IRQ resource defined\n"); 276 return irq_alarm; 277 } 278 279 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 280 priv->iobase = devm_ioremap_resource(dev, res); 281 if (IS_ERR(priv->iobase)) 282 return PTR_ERR(priv->iobase); 283 284 priv->clk = devm_clk_get(dev, "ahb"); 285 ret = clk_prepare_enable(priv->clk); 286 if (ret) { 287 dev_err(dev, "Failed to enable clk!\n"); 288 return ret; 289 } 290 291 ccr = ioread32(priv->iobase + HW_CCR); 292 /* if dev is not enabled, reset it */ 293 if ((ccr & (BM_CLKEN | BM_CTCRST)) != BM_CLKEN) { 294 iowrite32(BM_CTCRST, priv->iobase + HW_CCR); 295 ccr = 0; 296 } 297 298 iowrite32(BM_CLKEN | ccr, priv->iobase + HW_CCR); 299 iowrite32(0, priv->iobase + HW_CIIR); 300 iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR); 301 302 priv->rtc = devm_rtc_device_register(dev, dev_name(dev), 303 &asm9260_rtc_ops, THIS_MODULE); 304 if (IS_ERR(priv->rtc)) { 305 ret = PTR_ERR(priv->rtc); 306 dev_err(dev, "Failed to register RTC device: %d\n", ret); 307 goto err_return; 308 } 309 310 ret = devm_request_threaded_irq(dev, irq_alarm, NULL, 311 asm9260_rtc_irq, IRQF_ONESHOT, 312 dev_name(dev), priv); 313 if (ret < 0) { 314 dev_err(dev, "can't get irq %i, err %d\n", 315 irq_alarm, ret); 316 goto err_return; 317 } 318 319 return 0; 320 321 err_return: 322 clk_disable_unprepare(priv->clk); 323 return ret; 324 } 325 326 static int asm9260_rtc_remove(struct platform_device *pdev) 327 { 328 struct asm9260_rtc_priv *priv = platform_get_drvdata(pdev); 329 330 /* Disable alarm matching */ 331 iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR); 332 clk_disable_unprepare(priv->clk); 333 return 0; 334 } 335 336 static const struct of_device_id asm9260_dt_ids[] = { 337 { .compatible = "alphascale,asm9260-rtc", }, 338 {} 339 }; 340 341 static struct platform_driver asm9260_rtc_driver = { 342 .probe = asm9260_rtc_probe, 343 .remove = asm9260_rtc_remove, 344 .driver = { 345 .name = "asm9260-rtc", 346 .owner = THIS_MODULE, 347 .of_match_table = asm9260_dt_ids, 348 }, 349 }; 350 351 module_platform_driver(asm9260_rtc_driver); 352 353 MODULE_AUTHOR("Oleksij Rempel <linux@rempel-privat.de>"); 354 MODULE_DESCRIPTION("Alphascale asm9260 SoC Realtime Clock Driver (RTC)"); 355 MODULE_LICENSE("GPL"); 356