1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2016 Oleksij Rempel <linux@rempel-privat.de> 4 */ 5 6 #include <linux/clk.h> 7 #include <linux/interrupt.h> 8 #include <linux/io.h> 9 #include <linux/module.h> 10 #include <linux/of.h> 11 #include <linux/platform_device.h> 12 #include <linux/rtc.h> 13 14 /* Miscellaneous registers */ 15 /* Interrupt Location Register */ 16 #define HW_ILR 0x00 17 #define BM_RTCALF BIT(1) 18 #define BM_RTCCIF BIT(0) 19 20 /* Clock Control Register */ 21 #define HW_CCR 0x08 22 /* Calibration counter disable */ 23 #define BM_CCALOFF BIT(4) 24 /* Reset internal oscillator divider */ 25 #define BM_CTCRST BIT(1) 26 /* Clock Enable */ 27 #define BM_CLKEN BIT(0) 28 29 /* Counter Increment Interrupt Register */ 30 #define HW_CIIR 0x0C 31 #define BM_CIIR_IMYEAR BIT(7) 32 #define BM_CIIR_IMMON BIT(6) 33 #define BM_CIIR_IMDOY BIT(5) 34 #define BM_CIIR_IMDOW BIT(4) 35 #define BM_CIIR_IMDOM BIT(3) 36 #define BM_CIIR_IMHOUR BIT(2) 37 #define BM_CIIR_IMMIN BIT(1) 38 #define BM_CIIR_IMSEC BIT(0) 39 40 /* Alarm Mask Register */ 41 #define HW_AMR 0x10 42 #define BM_AMR_IMYEAR BIT(7) 43 #define BM_AMR_IMMON BIT(6) 44 #define BM_AMR_IMDOY BIT(5) 45 #define BM_AMR_IMDOW BIT(4) 46 #define BM_AMR_IMDOM BIT(3) 47 #define BM_AMR_IMHOUR BIT(2) 48 #define BM_AMR_IMMIN BIT(1) 49 #define BM_AMR_IMSEC BIT(0) 50 #define BM_AMR_OFF 0xff 51 52 /* Consolidated time registers */ 53 #define HW_CTIME0 0x14 54 #define BM_CTIME0_DOW_S 24 55 #define BM_CTIME0_DOW_M 0x7 56 #define BM_CTIME0_HOUR_S 16 57 #define BM_CTIME0_HOUR_M 0x1f 58 #define BM_CTIME0_MIN_S 8 59 #define BM_CTIME0_MIN_M 0x3f 60 #define BM_CTIME0_SEC_S 0 61 #define BM_CTIME0_SEC_M 0x3f 62 63 #define HW_CTIME1 0x18 64 #define BM_CTIME1_YEAR_S 16 65 #define BM_CTIME1_YEAR_M 0xfff 66 #define BM_CTIME1_MON_S 8 67 #define BM_CTIME1_MON_M 0xf 68 #define BM_CTIME1_DOM_S 0 69 #define BM_CTIME1_DOM_M 0x1f 70 71 #define HW_CTIME2 0x1C 72 #define BM_CTIME2_DOY_S 0 73 #define BM_CTIME2_DOY_M 0xfff 74 75 /* Time counter registers */ 76 #define HW_SEC 0x20 77 #define HW_MIN 0x24 78 #define HW_HOUR 0x28 79 #define HW_DOM 0x2C 80 #define HW_DOW 0x30 81 #define HW_DOY 0x34 82 #define HW_MONTH 0x38 83 #define HW_YEAR 0x3C 84 85 #define HW_CALIBRATION 0x40 86 #define BM_CALDIR_BACK BIT(17) 87 #define BM_CALVAL_M 0x1ffff 88 89 /* General purpose registers */ 90 #define HW_GPREG0 0x44 91 #define HW_GPREG1 0x48 92 #define HW_GPREG2 0x4C 93 #define HW_GPREG3 0x50 94 #define HW_GPREG4 0x54 95 96 /* Alarm register group */ 97 #define HW_ALSEC 0x60 98 #define HW_ALMIN 0x64 99 #define HW_ALHOUR 0x68 100 #define HW_ALDOM 0x6C 101 #define HW_ALDOW 0x70 102 #define HW_ALDOY 0x74 103 #define HW_ALMON 0x78 104 #define HW_ALYEAR 0x7C 105 106 struct asm9260_rtc_priv { 107 struct device *dev; 108 void __iomem *iobase; 109 struct rtc_device *rtc; 110 struct clk *clk; 111 }; 112 113 static irqreturn_t asm9260_rtc_irq(int irq, void *dev_id) 114 { 115 struct asm9260_rtc_priv *priv = dev_id; 116 u32 isr; 117 unsigned long events = 0; 118 119 rtc_lock(priv->rtc); 120 isr = ioread32(priv->iobase + HW_CIIR); 121 if (!isr) { 122 rtc_unlock(priv->rtc); 123 return IRQ_NONE; 124 } 125 126 iowrite32(0, priv->iobase + HW_CIIR); 127 rtc_unlock(priv->rtc); 128 129 events |= RTC_AF | RTC_IRQF; 130 131 rtc_update_irq(priv->rtc, 1, events); 132 133 return IRQ_HANDLED; 134 } 135 136 static int asm9260_rtc_read_time(struct device *dev, struct rtc_time *tm) 137 { 138 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); 139 u32 ctime0, ctime1, ctime2; 140 141 ctime0 = ioread32(priv->iobase + HW_CTIME0); 142 ctime1 = ioread32(priv->iobase + HW_CTIME1); 143 ctime2 = ioread32(priv->iobase + HW_CTIME2); 144 145 if (ctime1 != ioread32(priv->iobase + HW_CTIME1)) { 146 /* 147 * woops, counter flipped right now. Now we are safe 148 * to reread. 149 */ 150 ctime0 = ioread32(priv->iobase + HW_CTIME0); 151 ctime1 = ioread32(priv->iobase + HW_CTIME1); 152 ctime2 = ioread32(priv->iobase + HW_CTIME2); 153 } 154 155 tm->tm_sec = (ctime0 >> BM_CTIME0_SEC_S) & BM_CTIME0_SEC_M; 156 tm->tm_min = (ctime0 >> BM_CTIME0_MIN_S) & BM_CTIME0_MIN_M; 157 tm->tm_hour = (ctime0 >> BM_CTIME0_HOUR_S) & BM_CTIME0_HOUR_M; 158 tm->tm_wday = (ctime0 >> BM_CTIME0_DOW_S) & BM_CTIME0_DOW_M; 159 160 tm->tm_mday = (ctime1 >> BM_CTIME1_DOM_S) & BM_CTIME1_DOM_M; 161 tm->tm_mon = (ctime1 >> BM_CTIME1_MON_S) & BM_CTIME1_MON_M; 162 tm->tm_year = (ctime1 >> BM_CTIME1_YEAR_S) & BM_CTIME1_YEAR_M; 163 164 tm->tm_yday = (ctime2 >> BM_CTIME2_DOY_S) & BM_CTIME2_DOY_M; 165 166 return 0; 167 } 168 169 static int asm9260_rtc_set_time(struct device *dev, struct rtc_time *tm) 170 { 171 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); 172 173 /* 174 * make sure SEC counter will not flip other counter on write time, 175 * real value will be written at the enf of sequence. 176 */ 177 iowrite32(0, priv->iobase + HW_SEC); 178 179 iowrite32(tm->tm_year, priv->iobase + HW_YEAR); 180 iowrite32(tm->tm_mon, priv->iobase + HW_MONTH); 181 iowrite32(tm->tm_mday, priv->iobase + HW_DOM); 182 iowrite32(tm->tm_wday, priv->iobase + HW_DOW); 183 iowrite32(tm->tm_yday, priv->iobase + HW_DOY); 184 iowrite32(tm->tm_hour, priv->iobase + HW_HOUR); 185 iowrite32(tm->tm_min, priv->iobase + HW_MIN); 186 iowrite32(tm->tm_sec, priv->iobase + HW_SEC); 187 188 return 0; 189 } 190 191 static int asm9260_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 192 { 193 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); 194 195 alrm->time.tm_year = ioread32(priv->iobase + HW_ALYEAR); 196 alrm->time.tm_mon = ioread32(priv->iobase + HW_ALMON); 197 alrm->time.tm_mday = ioread32(priv->iobase + HW_ALDOM); 198 alrm->time.tm_wday = ioread32(priv->iobase + HW_ALDOW); 199 alrm->time.tm_yday = ioread32(priv->iobase + HW_ALDOY); 200 alrm->time.tm_hour = ioread32(priv->iobase + HW_ALHOUR); 201 alrm->time.tm_min = ioread32(priv->iobase + HW_ALMIN); 202 alrm->time.tm_sec = ioread32(priv->iobase + HW_ALSEC); 203 204 alrm->enabled = ioread32(priv->iobase + HW_AMR) ? 1 : 0; 205 alrm->pending = ioread32(priv->iobase + HW_CIIR) ? 1 : 0; 206 207 return rtc_valid_tm(&alrm->time); 208 } 209 210 static int asm9260_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 211 { 212 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); 213 214 iowrite32(alrm->time.tm_year, priv->iobase + HW_ALYEAR); 215 iowrite32(alrm->time.tm_mon, priv->iobase + HW_ALMON); 216 iowrite32(alrm->time.tm_mday, priv->iobase + HW_ALDOM); 217 iowrite32(alrm->time.tm_wday, priv->iobase + HW_ALDOW); 218 iowrite32(alrm->time.tm_yday, priv->iobase + HW_ALDOY); 219 iowrite32(alrm->time.tm_hour, priv->iobase + HW_ALHOUR); 220 iowrite32(alrm->time.tm_min, priv->iobase + HW_ALMIN); 221 iowrite32(alrm->time.tm_sec, priv->iobase + HW_ALSEC); 222 223 iowrite32(alrm->enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR); 224 225 return 0; 226 } 227 228 static int asm9260_alarm_irq_enable(struct device *dev, unsigned int enabled) 229 { 230 struct asm9260_rtc_priv *priv = dev_get_drvdata(dev); 231 232 iowrite32(enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR); 233 return 0; 234 } 235 236 static const struct rtc_class_ops asm9260_rtc_ops = { 237 .read_time = asm9260_rtc_read_time, 238 .set_time = asm9260_rtc_set_time, 239 .read_alarm = asm9260_rtc_read_alarm, 240 .set_alarm = asm9260_rtc_set_alarm, 241 .alarm_irq_enable = asm9260_alarm_irq_enable, 242 }; 243 244 static int asm9260_rtc_probe(struct platform_device *pdev) 245 { 246 struct asm9260_rtc_priv *priv; 247 struct device *dev = &pdev->dev; 248 int irq_alarm, ret; 249 u32 ccr; 250 251 priv = devm_kzalloc(dev, sizeof(struct asm9260_rtc_priv), GFP_KERNEL); 252 if (!priv) 253 return -ENOMEM; 254 255 priv->dev = &pdev->dev; 256 platform_set_drvdata(pdev, priv); 257 258 irq_alarm = platform_get_irq(pdev, 0); 259 if (irq_alarm < 0) 260 return irq_alarm; 261 262 priv->iobase = devm_platform_ioremap_resource(pdev, 0); 263 if (IS_ERR(priv->iobase)) 264 return PTR_ERR(priv->iobase); 265 266 priv->clk = devm_clk_get(dev, "ahb"); 267 if (IS_ERR(priv->clk)) 268 return PTR_ERR(priv->clk); 269 270 ret = clk_prepare_enable(priv->clk); 271 if (ret) { 272 dev_err(dev, "Failed to enable clk!\n"); 273 return ret; 274 } 275 276 ccr = ioread32(priv->iobase + HW_CCR); 277 /* if dev is not enabled, reset it */ 278 if ((ccr & (BM_CLKEN | BM_CTCRST)) != BM_CLKEN) { 279 iowrite32(BM_CTCRST, priv->iobase + HW_CCR); 280 ccr = 0; 281 } 282 283 iowrite32(BM_CLKEN | ccr, priv->iobase + HW_CCR); 284 iowrite32(0, priv->iobase + HW_CIIR); 285 iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR); 286 287 priv->rtc = devm_rtc_device_register(dev, dev_name(dev), 288 &asm9260_rtc_ops, THIS_MODULE); 289 if (IS_ERR(priv->rtc)) { 290 ret = PTR_ERR(priv->rtc); 291 dev_err(dev, "Failed to register RTC device: %d\n", ret); 292 goto err_return; 293 } 294 295 ret = devm_request_threaded_irq(dev, irq_alarm, NULL, 296 asm9260_rtc_irq, IRQF_ONESHOT, 297 dev_name(dev), priv); 298 if (ret < 0) { 299 dev_err(dev, "can't get irq %i, err %d\n", 300 irq_alarm, ret); 301 goto err_return; 302 } 303 304 return 0; 305 306 err_return: 307 clk_disable_unprepare(priv->clk); 308 return ret; 309 } 310 311 static void asm9260_rtc_remove(struct platform_device *pdev) 312 { 313 struct asm9260_rtc_priv *priv = platform_get_drvdata(pdev); 314 315 /* Disable alarm matching */ 316 iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR); 317 clk_disable_unprepare(priv->clk); 318 } 319 320 static const struct of_device_id asm9260_dt_ids[] = { 321 { .compatible = "alphascale,asm9260-rtc", }, 322 {} 323 }; 324 MODULE_DEVICE_TABLE(of, asm9260_dt_ids); 325 326 static struct platform_driver asm9260_rtc_driver = { 327 .probe = asm9260_rtc_probe, 328 .remove_new = asm9260_rtc_remove, 329 .driver = { 330 .name = "asm9260-rtc", 331 .of_match_table = asm9260_dt_ids, 332 }, 333 }; 334 335 module_platform_driver(asm9260_rtc_driver); 336 337 MODULE_AUTHOR("Oleksij Rempel <linux@rempel-privat.de>"); 338 MODULE_DESCRIPTION("Alphascale asm9260 SoC Realtime Clock Driver (RTC)"); 339 MODULE_LICENSE("GPL"); 340