1 /* 2 * RTC Driver for X-Powers AC100 3 * 4 * Copyright (c) 2016 Chen-Yu Tsai 5 * 6 * Chen-Yu Tsai <[email protected]> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 15 * more details. 16 */ 17 18 #include <linux/bcd.h> 19 #include <linux/device.h> 20 #include <linux/interrupt.h> 21 #include <linux/kernel.h> 22 #include <linux/mfd/ac100.h> 23 #include <linux/module.h> 24 #include <linux/mutex.h> 25 #include <linux/of.h> 26 #include <linux/platform_device.h> 27 #include <linux/regmap.h> 28 #include <linux/rtc.h> 29 #include <linux/types.h> 30 31 /* Control register */ 32 #define AC100_RTC_CTRL_24HOUR BIT(0) 33 34 /* RTC */ 35 #define AC100_RTC_SEC_MASK GENMASK(6, 0) 36 #define AC100_RTC_MIN_MASK GENMASK(6, 0) 37 #define AC100_RTC_HOU_MASK GENMASK(5, 0) 38 #define AC100_RTC_WEE_MASK GENMASK(2, 0) 39 #define AC100_RTC_DAY_MASK GENMASK(5, 0) 40 #define AC100_RTC_MON_MASK GENMASK(4, 0) 41 #define AC100_RTC_YEA_MASK GENMASK(7, 0) 42 #define AC100_RTC_YEA_LEAP BIT(15) 43 #define AC100_RTC_UPD_TRIGGER BIT(15) 44 45 /* Alarm (wall clock) */ 46 #define AC100_ALM_INT_ENABLE BIT(0) 47 48 #define AC100_ALM_SEC_MASK GENMASK(6, 0) 49 #define AC100_ALM_MIN_MASK GENMASK(6, 0) 50 #define AC100_ALM_HOU_MASK GENMASK(5, 0) 51 #define AC100_ALM_WEE_MASK GENMASK(2, 0) 52 #define AC100_ALM_DAY_MASK GENMASK(5, 0) 53 #define AC100_ALM_MON_MASK GENMASK(4, 0) 54 #define AC100_ALM_YEA_MASK GENMASK(7, 0) 55 #define AC100_ALM_ENABLE_FLAG BIT(15) 56 #define AC100_ALM_UPD_TRIGGER BIT(15) 57 58 /* 59 * The year parameter passed to the driver is usually an offset relative to 60 * the year 1900. This macro is used to convert this offset to another one 61 * relative to the minimum year allowed by the hardware. 62 * 63 * The year range is 1970 - 2069. This range is selected to match Allwinner's 64 * driver. 65 */ 66 #define AC100_YEAR_MIN 1970 67 #define AC100_YEAR_MAX 2069 68 #define AC100_YEAR_OFF (AC100_YEAR_MIN - 1900) 69 70 struct ac100_rtc_dev { 71 struct rtc_device *rtc; 72 struct device *dev; 73 struct regmap *regmap; 74 int irq; 75 unsigned long alarm; 76 }; 77 78 static int ac100_rtc_get_time(struct device *dev, struct rtc_time *rtc_tm) 79 { 80 struct ac100_rtc_dev *chip = dev_get_drvdata(dev); 81 struct regmap *regmap = chip->regmap; 82 u16 reg[7]; 83 int ret; 84 85 ret = regmap_bulk_read(regmap, AC100_RTC_SEC, reg, 7); 86 if (ret) 87 return ret; 88 89 rtc_tm->tm_sec = bcd2bin(reg[0] & AC100_RTC_SEC_MASK); 90 rtc_tm->tm_min = bcd2bin(reg[1] & AC100_RTC_MIN_MASK); 91 rtc_tm->tm_hour = bcd2bin(reg[2] & AC100_RTC_HOU_MASK); 92 rtc_tm->tm_wday = bcd2bin(reg[3] & AC100_RTC_WEE_MASK); 93 rtc_tm->tm_mday = bcd2bin(reg[4] & AC100_RTC_DAY_MASK); 94 rtc_tm->tm_mon = bcd2bin(reg[5] & AC100_RTC_MON_MASK) - 1; 95 rtc_tm->tm_year = bcd2bin(reg[6] & AC100_RTC_YEA_MASK) + 96 AC100_YEAR_OFF; 97 98 return rtc_valid_tm(rtc_tm); 99 } 100 101 static int ac100_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm) 102 { 103 struct ac100_rtc_dev *chip = dev_get_drvdata(dev); 104 struct regmap *regmap = chip->regmap; 105 int year; 106 u16 reg[8]; 107 108 /* our RTC has a limited year range... */ 109 year = rtc_tm->tm_year - AC100_YEAR_OFF; 110 if (year < 0 || year > (AC100_YEAR_MAX - 1900)) { 111 dev_err(dev, "rtc only supports year in range %d - %d\n", 112 AC100_YEAR_MIN, AC100_YEAR_MAX); 113 return -EINVAL; 114 } 115 116 /* convert to BCD */ 117 reg[0] = bin2bcd(rtc_tm->tm_sec) & AC100_RTC_SEC_MASK; 118 reg[1] = bin2bcd(rtc_tm->tm_min) & AC100_RTC_MIN_MASK; 119 reg[2] = bin2bcd(rtc_tm->tm_hour) & AC100_RTC_HOU_MASK; 120 reg[3] = bin2bcd(rtc_tm->tm_wday) & AC100_RTC_WEE_MASK; 121 reg[4] = bin2bcd(rtc_tm->tm_mday) & AC100_RTC_DAY_MASK; 122 reg[5] = bin2bcd(rtc_tm->tm_mon + 1) & AC100_RTC_MON_MASK; 123 reg[6] = bin2bcd(year) & AC100_RTC_YEA_MASK; 124 /* trigger write */ 125 reg[7] = AC100_RTC_UPD_TRIGGER; 126 127 /* Is it a leap year? */ 128 if (is_leap_year(year + AC100_YEAR_OFF + 1900)) 129 reg[6] |= AC100_RTC_YEA_LEAP; 130 131 return regmap_bulk_write(regmap, AC100_RTC_SEC, reg, 8); 132 } 133 134 static int ac100_rtc_alarm_irq_enable(struct device *dev, unsigned int en) 135 { 136 struct ac100_rtc_dev *chip = dev_get_drvdata(dev); 137 struct regmap *regmap = chip->regmap; 138 unsigned int val; 139 140 val = en ? AC100_ALM_INT_ENABLE : 0; 141 142 return regmap_write(regmap, AC100_ALM_INT_ENA, val); 143 } 144 145 static int ac100_rtc_get_alarm(struct device *dev, struct rtc_wkalrm *alrm) 146 { 147 struct ac100_rtc_dev *chip = dev_get_drvdata(dev); 148 struct regmap *regmap = chip->regmap; 149 struct rtc_time *alrm_tm = &alrm->time; 150 u16 reg[7]; 151 unsigned int val; 152 int ret; 153 154 ret = regmap_read(regmap, AC100_ALM_INT_ENA, &val); 155 if (ret) 156 return ret; 157 158 alrm->enabled = !!(val & AC100_ALM_INT_ENABLE); 159 160 ret = regmap_bulk_read(regmap, AC100_ALM_SEC, reg, 7); 161 if (ret) 162 return ret; 163 164 alrm_tm->tm_sec = bcd2bin(reg[0] & AC100_ALM_SEC_MASK); 165 alrm_tm->tm_min = bcd2bin(reg[1] & AC100_ALM_MIN_MASK); 166 alrm_tm->tm_hour = bcd2bin(reg[2] & AC100_ALM_HOU_MASK); 167 alrm_tm->tm_wday = bcd2bin(reg[3] & AC100_ALM_WEE_MASK); 168 alrm_tm->tm_mday = bcd2bin(reg[4] & AC100_ALM_DAY_MASK); 169 alrm_tm->tm_mon = bcd2bin(reg[5] & AC100_ALM_MON_MASK) - 1; 170 alrm_tm->tm_year = bcd2bin(reg[6] & AC100_ALM_YEA_MASK) + 171 AC100_YEAR_OFF; 172 173 return 0; 174 } 175 176 static int ac100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 177 { 178 struct ac100_rtc_dev *chip = dev_get_drvdata(dev); 179 struct regmap *regmap = chip->regmap; 180 struct rtc_time *alrm_tm = &alrm->time; 181 u16 reg[8]; 182 int year; 183 int ret; 184 185 /* our alarm has a limited year range... */ 186 year = alrm_tm->tm_year - AC100_YEAR_OFF; 187 if (year < 0 || year > (AC100_YEAR_MAX - 1900)) { 188 dev_err(dev, "alarm only supports year in range %d - %d\n", 189 AC100_YEAR_MIN, AC100_YEAR_MAX); 190 return -EINVAL; 191 } 192 193 /* convert to BCD */ 194 reg[0] = (bin2bcd(alrm_tm->tm_sec) & AC100_ALM_SEC_MASK) | 195 AC100_ALM_ENABLE_FLAG; 196 reg[1] = (bin2bcd(alrm_tm->tm_min) & AC100_ALM_MIN_MASK) | 197 AC100_ALM_ENABLE_FLAG; 198 reg[2] = (bin2bcd(alrm_tm->tm_hour) & AC100_ALM_HOU_MASK) | 199 AC100_ALM_ENABLE_FLAG; 200 /* Do not enable weekday alarm */ 201 reg[3] = bin2bcd(alrm_tm->tm_wday) & AC100_ALM_WEE_MASK; 202 reg[4] = (bin2bcd(alrm_tm->tm_mday) & AC100_ALM_DAY_MASK) | 203 AC100_ALM_ENABLE_FLAG; 204 reg[5] = (bin2bcd(alrm_tm->tm_mon + 1) & AC100_ALM_MON_MASK) | 205 AC100_ALM_ENABLE_FLAG; 206 reg[6] = (bin2bcd(year) & AC100_ALM_YEA_MASK) | 207 AC100_ALM_ENABLE_FLAG; 208 /* trigger write */ 209 reg[7] = AC100_ALM_UPD_TRIGGER; 210 211 ret = regmap_bulk_write(regmap, AC100_ALM_SEC, reg, 8); 212 if (ret) 213 return ret; 214 215 return ac100_rtc_alarm_irq_enable(dev, alrm->enabled); 216 } 217 218 static irqreturn_t ac100_rtc_irq(int irq, void *data) 219 { 220 struct ac100_rtc_dev *chip = data; 221 struct regmap *regmap = chip->regmap; 222 unsigned int val = 0; 223 int ret; 224 225 mutex_lock(&chip->rtc->ops_lock); 226 227 /* read status */ 228 ret = regmap_read(regmap, AC100_ALM_INT_STA, &val); 229 if (ret) 230 goto out; 231 232 if (val & AC100_ALM_INT_ENABLE) { 233 /* signal rtc framework */ 234 rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF); 235 236 /* clear status */ 237 ret = regmap_write(regmap, AC100_ALM_INT_STA, val); 238 if (ret) 239 goto out; 240 241 /* disable interrupt */ 242 ret = ac100_rtc_alarm_irq_enable(chip->dev, 0); 243 if (ret) 244 goto out; 245 } 246 247 out: 248 mutex_unlock(&chip->rtc->ops_lock); 249 return IRQ_HANDLED; 250 } 251 252 static const struct rtc_class_ops ac100_rtc_ops = { 253 .read_time = ac100_rtc_get_time, 254 .set_time = ac100_rtc_set_time, 255 .read_alarm = ac100_rtc_get_alarm, 256 .set_alarm = ac100_rtc_set_alarm, 257 .alarm_irq_enable = ac100_rtc_alarm_irq_enable, 258 }; 259 260 static int ac100_rtc_probe(struct platform_device *pdev) 261 { 262 struct ac100_dev *ac100 = dev_get_drvdata(pdev->dev.parent); 263 struct ac100_rtc_dev *chip; 264 int ret; 265 266 chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); 267 platform_set_drvdata(pdev, chip); 268 chip->dev = &pdev->dev; 269 chip->regmap = ac100->regmap; 270 271 chip->irq = platform_get_irq(pdev, 0); 272 if (chip->irq < 0) { 273 dev_err(&pdev->dev, "No IRQ resource\n"); 274 return chip->irq; 275 } 276 277 ret = devm_request_threaded_irq(&pdev->dev, chip->irq, NULL, 278 ac100_rtc_irq, 279 IRQF_SHARED | IRQF_ONESHOT, 280 dev_name(&pdev->dev), chip); 281 if (ret) { 282 dev_err(&pdev->dev, "Could not request IRQ\n"); 283 return ret; 284 } 285 286 /* always use 24 hour mode */ 287 regmap_write_bits(chip->regmap, AC100_RTC_CTRL, AC100_RTC_CTRL_24HOUR, 288 AC100_RTC_CTRL_24HOUR); 289 290 /* disable counter alarm interrupt */ 291 regmap_write(chip->regmap, AC100_ALM_INT_ENA, 0); 292 293 /* clear counter alarm pending interrupts */ 294 regmap_write(chip->regmap, AC100_ALM_INT_STA, AC100_ALM_INT_ENABLE); 295 296 chip->rtc = devm_rtc_device_register(&pdev->dev, "rtc-ac100", 297 &ac100_rtc_ops, THIS_MODULE); 298 if (IS_ERR(chip->rtc)) { 299 dev_err(&pdev->dev, "unable to register device\n"); 300 return PTR_ERR(chip->rtc); 301 } 302 303 dev_info(&pdev->dev, "RTC enabled\n"); 304 305 return 0; 306 } 307 308 static const struct of_device_id ac100_rtc_match[] = { 309 { .compatible = "x-powers,ac100-rtc" }, 310 { }, 311 }; 312 MODULE_DEVICE_TABLE(of, ac100_rtc_match); 313 314 static struct platform_driver ac100_rtc_driver = { 315 .probe = ac100_rtc_probe, 316 .driver = { 317 .name = "ac100-rtc", 318 .of_match_table = of_match_ptr(ac100_rtc_match), 319 }, 320 }; 321 module_platform_driver(ac100_rtc_driver); 322 323 MODULE_DESCRIPTION("X-Powers AC100 RTC driver"); 324 MODULE_AUTHOR("Chen-Yu Tsai <[email protected]>"); 325 MODULE_LICENSE("GPL v2"); 326