1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * TI LP8788 MFD - rtc driver 4 * 5 * Copyright 2012 Texas Instruments 6 * 7 * Author: Milo(Woogyom) Kim <milo.kim@ti.com> 8 */ 9 10 #include <linux/err.h> 11 #include <linux/irqdomain.h> 12 #include <linux/mfd/lp8788.h> 13 #include <linux/module.h> 14 #include <linux/platform_device.h> 15 #include <linux/rtc.h> 16 #include <linux/slab.h> 17 18 /* register address */ 19 #define LP8788_INTEN_3 0x05 20 #define LP8788_RTC_UNLOCK 0x64 21 #define LP8788_RTC_SEC 0x70 22 #define LP8788_ALM1_SEC 0x77 23 #define LP8788_ALM1_EN 0x7D 24 #define LP8788_ALM2_SEC 0x7E 25 #define LP8788_ALM2_EN 0x84 26 27 /* mask/shift bits */ 28 #define LP8788_INT_RTC_ALM1_M BIT(1) /* Addr 05h */ 29 #define LP8788_INT_RTC_ALM1_S 1 30 #define LP8788_INT_RTC_ALM2_M BIT(2) /* Addr 05h */ 31 #define LP8788_INT_RTC_ALM2_S 2 32 #define LP8788_ALM_EN_M BIT(7) /* Addr 7Dh or 84h */ 33 #define LP8788_ALM_EN_S 7 34 35 #define DEFAULT_ALARM_SEL LP8788_ALARM_1 36 #define LP8788_MONTH_OFFSET 1 37 #define LP8788_BASE_YEAR 2000 38 #define MAX_WDAY_BITS 7 39 #define LP8788_WDAY_SET 1 40 #define RTC_UNLOCK 0x1 41 #define RTC_LATCH 0x2 42 #define ALARM_IRQ_FLAG (RTC_IRQF | RTC_AF) 43 44 enum lp8788_time { 45 LPTIME_SEC, 46 LPTIME_MIN, 47 LPTIME_HOUR, 48 LPTIME_MDAY, 49 LPTIME_MON, 50 LPTIME_YEAR, 51 LPTIME_WDAY, 52 LPTIME_MAX, 53 }; 54 55 struct lp8788_rtc { 56 struct lp8788 *lp; 57 struct rtc_device *rdev; 58 enum lp8788_alarm_sel alarm; 59 int irq; 60 }; 61 62 static const u8 addr_alarm_sec[LP8788_ALARM_MAX] = { 63 LP8788_ALM1_SEC, 64 LP8788_ALM2_SEC, 65 }; 66 67 static const u8 addr_alarm_en[LP8788_ALARM_MAX] = { 68 LP8788_ALM1_EN, 69 LP8788_ALM2_EN, 70 }; 71 72 static const u8 mask_alarm_en[LP8788_ALARM_MAX] = { 73 LP8788_INT_RTC_ALM1_M, 74 LP8788_INT_RTC_ALM2_M, 75 }; 76 77 static const u8 shift_alarm_en[LP8788_ALARM_MAX] = { 78 LP8788_INT_RTC_ALM1_S, 79 LP8788_INT_RTC_ALM2_S, 80 }; 81 82 static int _to_tm_wday(u8 lp8788_wday) 83 { 84 int i; 85 86 if (lp8788_wday == 0) 87 return 0; 88 89 /* lookup defined weekday from read register value */ 90 for (i = 0; i < MAX_WDAY_BITS; i++) { 91 if ((lp8788_wday >> i) == LP8788_WDAY_SET) 92 break; 93 } 94 95 return i + 1; 96 } 97 98 static inline int _to_lp8788_wday(int tm_wday) 99 { 100 return LP8788_WDAY_SET << (tm_wday - 1); 101 } 102 103 static void lp8788_rtc_unlock(struct lp8788 *lp) 104 { 105 lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_UNLOCK); 106 lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_LATCH); 107 } 108 109 static int lp8788_rtc_read_time(struct device *dev, struct rtc_time *tm) 110 { 111 struct lp8788_rtc *rtc = dev_get_drvdata(dev); 112 struct lp8788 *lp = rtc->lp; 113 u8 data[LPTIME_MAX]; 114 int ret; 115 116 lp8788_rtc_unlock(lp); 117 118 ret = lp8788_read_multi_bytes(lp, LP8788_RTC_SEC, data, LPTIME_MAX); 119 if (ret) 120 return ret; 121 122 tm->tm_sec = data[LPTIME_SEC]; 123 tm->tm_min = data[LPTIME_MIN]; 124 tm->tm_hour = data[LPTIME_HOUR]; 125 tm->tm_mday = data[LPTIME_MDAY]; 126 tm->tm_mon = data[LPTIME_MON] - LP8788_MONTH_OFFSET; 127 tm->tm_year = data[LPTIME_YEAR] + LP8788_BASE_YEAR - 1900; 128 tm->tm_wday = _to_tm_wday(data[LPTIME_WDAY]); 129 130 return 0; 131 } 132 133 static int lp8788_rtc_set_time(struct device *dev, struct rtc_time *tm) 134 { 135 struct lp8788_rtc *rtc = dev_get_drvdata(dev); 136 struct lp8788 *lp = rtc->lp; 137 u8 data[LPTIME_MAX - 1]; 138 int ret, i, year; 139 140 year = tm->tm_year + 1900 - LP8788_BASE_YEAR; 141 if (year < 0) { 142 dev_err(lp->dev, "invalid year: %d\n", year); 143 return -EINVAL; 144 } 145 146 /* because rtc weekday is a readonly register, do not update */ 147 data[LPTIME_SEC] = tm->tm_sec; 148 data[LPTIME_MIN] = tm->tm_min; 149 data[LPTIME_HOUR] = tm->tm_hour; 150 data[LPTIME_MDAY] = tm->tm_mday; 151 data[LPTIME_MON] = tm->tm_mon + LP8788_MONTH_OFFSET; 152 data[LPTIME_YEAR] = year; 153 154 for (i = 0; i < ARRAY_SIZE(data); i++) { 155 ret = lp8788_write_byte(lp, LP8788_RTC_SEC + i, data[i]); 156 if (ret) 157 return ret; 158 } 159 160 return 0; 161 } 162 163 static int lp8788_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 164 { 165 struct lp8788_rtc *rtc = dev_get_drvdata(dev); 166 struct lp8788 *lp = rtc->lp; 167 struct rtc_time *tm = &alarm->time; 168 u8 addr, data[LPTIME_MAX]; 169 int ret; 170 171 addr = addr_alarm_sec[rtc->alarm]; 172 ret = lp8788_read_multi_bytes(lp, addr, data, LPTIME_MAX); 173 if (ret) 174 return ret; 175 176 tm->tm_sec = data[LPTIME_SEC]; 177 tm->tm_min = data[LPTIME_MIN]; 178 tm->tm_hour = data[LPTIME_HOUR]; 179 tm->tm_mday = data[LPTIME_MDAY]; 180 tm->tm_mon = data[LPTIME_MON] - LP8788_MONTH_OFFSET; 181 tm->tm_year = data[LPTIME_YEAR] + LP8788_BASE_YEAR - 1900; 182 tm->tm_wday = _to_tm_wday(data[LPTIME_WDAY]); 183 alarm->enabled = data[LPTIME_WDAY] & LP8788_ALM_EN_M; 184 185 return 0; 186 } 187 188 static int lp8788_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 189 { 190 struct lp8788_rtc *rtc = dev_get_drvdata(dev); 191 struct lp8788 *lp = rtc->lp; 192 struct rtc_time *tm = &alarm->time; 193 u8 addr, data[LPTIME_MAX]; 194 int ret, i, year; 195 196 year = tm->tm_year + 1900 - LP8788_BASE_YEAR; 197 if (year < 0) { 198 dev_err(lp->dev, "invalid year: %d\n", year); 199 return -EINVAL; 200 } 201 202 data[LPTIME_SEC] = tm->tm_sec; 203 data[LPTIME_MIN] = tm->tm_min; 204 data[LPTIME_HOUR] = tm->tm_hour; 205 data[LPTIME_MDAY] = tm->tm_mday; 206 data[LPTIME_MON] = tm->tm_mon + LP8788_MONTH_OFFSET; 207 data[LPTIME_YEAR] = year; 208 data[LPTIME_WDAY] = _to_lp8788_wday(tm->tm_wday); 209 210 for (i = 0; i < ARRAY_SIZE(data); i++) { 211 addr = addr_alarm_sec[rtc->alarm] + i; 212 ret = lp8788_write_byte(lp, addr, data[i]); 213 if (ret) 214 return ret; 215 } 216 217 alarm->enabled = 1; 218 addr = addr_alarm_en[rtc->alarm]; 219 220 return lp8788_update_bits(lp, addr, LP8788_ALM_EN_M, 221 alarm->enabled << LP8788_ALM_EN_S); 222 } 223 224 static int lp8788_alarm_irq_enable(struct device *dev, unsigned int enable) 225 { 226 struct lp8788_rtc *rtc = dev_get_drvdata(dev); 227 struct lp8788 *lp = rtc->lp; 228 u8 mask, shift; 229 230 if (!rtc->irq) 231 return -EIO; 232 233 mask = mask_alarm_en[rtc->alarm]; 234 shift = shift_alarm_en[rtc->alarm]; 235 236 return lp8788_update_bits(lp, LP8788_INTEN_3, mask, enable << shift); 237 } 238 239 static const struct rtc_class_ops lp8788_rtc_ops = { 240 .read_time = lp8788_rtc_read_time, 241 .set_time = lp8788_rtc_set_time, 242 .read_alarm = lp8788_read_alarm, 243 .set_alarm = lp8788_set_alarm, 244 .alarm_irq_enable = lp8788_alarm_irq_enable, 245 }; 246 247 static irqreturn_t lp8788_alarm_irq_handler(int irq, void *ptr) 248 { 249 struct lp8788_rtc *rtc = ptr; 250 251 rtc_update_irq(rtc->rdev, 1, ALARM_IRQ_FLAG); 252 return IRQ_HANDLED; 253 } 254 255 static int lp8788_alarm_irq_register(struct platform_device *pdev, 256 struct lp8788_rtc *rtc) 257 { 258 struct resource *r; 259 struct lp8788 *lp = rtc->lp; 260 struct irq_domain *irqdm = lp->irqdm; 261 int irq; 262 263 rtc->irq = 0; 264 265 /* even the alarm IRQ number is not specified, rtc time should work */ 266 r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, LP8788_ALM_IRQ); 267 if (!r) 268 return 0; 269 270 if (rtc->alarm == LP8788_ALARM_1) 271 irq = r->start; 272 else 273 irq = r->end; 274 275 rtc->irq = irq_create_mapping(irqdm, irq); 276 277 return devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, 278 lp8788_alarm_irq_handler, 279 0, LP8788_ALM_IRQ, rtc); 280 } 281 282 static int lp8788_rtc_probe(struct platform_device *pdev) 283 { 284 struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent); 285 struct lp8788_rtc *rtc; 286 struct device *dev = &pdev->dev; 287 288 rtc = devm_kzalloc(dev, sizeof(struct lp8788_rtc), GFP_KERNEL); 289 if (!rtc) 290 return -ENOMEM; 291 292 rtc->lp = lp; 293 rtc->alarm = lp->pdata ? lp->pdata->alarm_sel : DEFAULT_ALARM_SEL; 294 platform_set_drvdata(pdev, rtc); 295 296 device_init_wakeup(dev, 1); 297 298 rtc->rdev = devm_rtc_device_register(dev, "lp8788_rtc", 299 &lp8788_rtc_ops, THIS_MODULE); 300 if (IS_ERR(rtc->rdev)) { 301 dev_err(dev, "can not register rtc device\n"); 302 return PTR_ERR(rtc->rdev); 303 } 304 305 if (lp8788_alarm_irq_register(pdev, rtc)) 306 dev_warn(lp->dev, "no rtc irq handler\n"); 307 308 return 0; 309 } 310 311 static struct platform_driver lp8788_rtc_driver = { 312 .probe = lp8788_rtc_probe, 313 .driver = { 314 .name = LP8788_DEV_RTC, 315 }, 316 }; 317 module_platform_driver(lp8788_rtc_driver); 318 319 MODULE_DESCRIPTION("Texas Instruments LP8788 RTC Driver"); 320 MODULE_AUTHOR("Milo Kim"); 321 MODULE_LICENSE("GPL"); 322 MODULE_ALIAS("platform:lp8788-rtc"); 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