1 /* 2 * rtc-tps6586x.c: RTC driver for TI PMIC TPS6586X 3 * 4 * Copyright (c) 2012, NVIDIA Corporation. 5 * 6 * Author: Laxman Dewangan <ldewangan@nvidia.com> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation version 2. 11 * 12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind, 13 * whether express or implied; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 20 * 02111-1307, USA 21 */ 22 23 #include <linux/device.h> 24 #include <linux/err.h> 25 #include <linux/init.h> 26 #include <linux/kernel.h> 27 #include <linux/mfd/tps6586x.h> 28 #include <linux/module.h> 29 #include <linux/platform_device.h> 30 #include <linux/pm_runtime.h> 31 #include <linux/rtc.h> 32 #include <linux/slab.h> 33 34 #define RTC_CTRL 0xc0 35 #define POR_RESET_N BIT(7) 36 #define OSC_SRC_SEL BIT(6) 37 #define RTC_ENABLE BIT(5) /* enables alarm */ 38 #define RTC_BUF_ENABLE BIT(4) /* 32 KHz buffer enable */ 39 #define PRE_BYPASS BIT(3) /* 0=1KHz or 1=32KHz updates */ 40 #define CL_SEL_MASK (BIT(2)|BIT(1)) 41 #define CL_SEL_POS 1 42 #define RTC_ALARM1_HI 0xc1 43 #define RTC_COUNT4 0xc6 44 45 /* start a PMU RTC access by reading the register prior to the RTC_COUNT4 */ 46 #define RTC_COUNT4_DUMMYREAD 0xc5 47 48 /*only 14-bits width in second*/ 49 #define ALM1_VALID_RANGE_IN_SEC 0x3FFF 50 51 #define TPS6586X_RTC_CL_SEL_1_5PF 0x0 52 #define TPS6586X_RTC_CL_SEL_6_5PF 0x1 53 #define TPS6586X_RTC_CL_SEL_7_5PF 0x2 54 #define TPS6586X_RTC_CL_SEL_12_5PF 0x3 55 56 struct tps6586x_rtc { 57 struct device *dev; 58 struct rtc_device *rtc; 59 int irq; 60 bool irq_en; 61 unsigned long long epoch_start; 62 }; 63 64 static inline struct device *to_tps6586x_dev(struct device *dev) 65 { 66 return dev->parent; 67 } 68 69 static int tps6586x_rtc_read_time(struct device *dev, struct rtc_time *tm) 70 { 71 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 72 struct device *tps_dev = to_tps6586x_dev(dev); 73 unsigned long long ticks = 0; 74 unsigned long seconds; 75 u8 buff[6]; 76 int ret; 77 int i; 78 79 ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(buff), buff); 80 if (ret < 0) { 81 dev_err(dev, "read counter failed with err %d\n", ret); 82 return ret; 83 } 84 85 for (i = 1; i < sizeof(buff); i++) { 86 ticks <<= 8; 87 ticks |= buff[i]; 88 } 89 90 seconds = ticks >> 10; 91 seconds += rtc->epoch_start; 92 rtc_time_to_tm(seconds, tm); 93 return rtc_valid_tm(tm); 94 } 95 96 static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm) 97 { 98 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 99 struct device *tps_dev = to_tps6586x_dev(dev); 100 unsigned long long ticks; 101 unsigned long seconds; 102 u8 buff[5]; 103 int ret; 104 105 rtc_tm_to_time(tm, &seconds); 106 if (seconds < rtc->epoch_start) { 107 dev_err(dev, "requested time unsupported\n"); 108 return -EINVAL; 109 } 110 seconds -= rtc->epoch_start; 111 112 ticks = (unsigned long long)seconds << 10; 113 buff[0] = (ticks >> 32) & 0xff; 114 buff[1] = (ticks >> 24) & 0xff; 115 buff[2] = (ticks >> 16) & 0xff; 116 buff[3] = (ticks >> 8) & 0xff; 117 buff[4] = ticks & 0xff; 118 119 /* Disable RTC before changing time */ 120 ret = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE); 121 if (ret < 0) { 122 dev_err(dev, "failed to clear RTC_ENABLE\n"); 123 return ret; 124 } 125 126 ret = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff); 127 if (ret < 0) { 128 dev_err(dev, "failed to program new time\n"); 129 return ret; 130 } 131 132 /* Enable RTC */ 133 ret = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE); 134 if (ret < 0) { 135 dev_err(dev, "failed to set RTC_ENABLE\n"); 136 return ret; 137 } 138 return 0; 139 } 140 141 static int tps6586x_rtc_alarm_irq_enable(struct device *dev, 142 unsigned int enabled) 143 { 144 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 145 146 if (enabled && !rtc->irq_en) { 147 enable_irq(rtc->irq); 148 rtc->irq_en = true; 149 } else if (!enabled && rtc->irq_en) { 150 disable_irq(rtc->irq); 151 rtc->irq_en = false; 152 } 153 return 0; 154 } 155 156 static int tps6586x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 157 { 158 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 159 struct device *tps_dev = to_tps6586x_dev(dev); 160 unsigned long seconds; 161 unsigned long ticks; 162 unsigned long rtc_current_time; 163 unsigned long long rticks = 0; 164 u8 buff[3]; 165 u8 rbuff[6]; 166 int ret; 167 int i; 168 169 rtc_tm_to_time(&alrm->time, &seconds); 170 171 if (alrm->enabled && (seconds < rtc->epoch_start)) { 172 dev_err(dev, "can't set alarm to requested time\n"); 173 return -EINVAL; 174 } 175 176 ret = tps6586x_rtc_alarm_irq_enable(dev, alrm->enabled); 177 if (ret < 0) { 178 dev_err(dev, "can't set alarm irq, err %d\n", ret); 179 return ret; 180 } 181 182 seconds -= rtc->epoch_start; 183 ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, 184 sizeof(rbuff), rbuff); 185 if (ret < 0) { 186 dev_err(dev, "read counter failed with err %d\n", ret); 187 return ret; 188 } 189 190 for (i = 1; i < sizeof(rbuff); i++) { 191 rticks <<= 8; 192 rticks |= rbuff[i]; 193 } 194 195 rtc_current_time = rticks >> 10; 196 if ((seconds - rtc_current_time) > ALM1_VALID_RANGE_IN_SEC) 197 seconds = rtc_current_time - 1; 198 199 ticks = (unsigned long long)seconds << 10; 200 buff[0] = (ticks >> 16) & 0xff; 201 buff[1] = (ticks >> 8) & 0xff; 202 buff[2] = ticks & 0xff; 203 204 ret = tps6586x_writes(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff); 205 if (ret) 206 dev_err(dev, "programming alarm failed with err %d\n", ret); 207 208 return ret; 209 } 210 211 static int tps6586x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 212 { 213 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 214 struct device *tps_dev = to_tps6586x_dev(dev); 215 unsigned long ticks; 216 unsigned long seconds; 217 u8 buff[3]; 218 int ret; 219 220 ret = tps6586x_reads(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff); 221 if (ret) { 222 dev_err(dev, "read RTC_ALARM1_HI failed with err %d\n", ret); 223 return ret; 224 } 225 226 ticks = (buff[0] << 16) | (buff[1] << 8) | buff[2]; 227 seconds = ticks >> 10; 228 seconds += rtc->epoch_start; 229 230 rtc_time_to_tm(seconds, &alrm->time); 231 return 0; 232 } 233 234 static const struct rtc_class_ops tps6586x_rtc_ops = { 235 .read_time = tps6586x_rtc_read_time, 236 .set_time = tps6586x_rtc_set_time, 237 .set_alarm = tps6586x_rtc_set_alarm, 238 .read_alarm = tps6586x_rtc_read_alarm, 239 .alarm_irq_enable = tps6586x_rtc_alarm_irq_enable, 240 }; 241 242 static irqreturn_t tps6586x_rtc_irq(int irq, void *data) 243 { 244 struct tps6586x_rtc *rtc = data; 245 246 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); 247 return IRQ_HANDLED; 248 } 249 250 static int tps6586x_rtc_probe(struct platform_device *pdev) 251 { 252 struct device *tps_dev = to_tps6586x_dev(&pdev->dev); 253 struct tps6586x_rtc *rtc; 254 int ret; 255 256 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); 257 if (!rtc) 258 return -ENOMEM; 259 260 rtc->dev = &pdev->dev; 261 rtc->irq = platform_get_irq(pdev, 0); 262 263 /* Set epoch start as 00:00:00:01:01:2009 */ 264 rtc->epoch_start = mktime(2009, 1, 1, 0, 0, 0); 265 266 /* 1 kHz tick mode, enable tick counting */ 267 ret = tps6586x_update(tps_dev, RTC_CTRL, 268 RTC_ENABLE | OSC_SRC_SEL | 269 ((TPS6586X_RTC_CL_SEL_1_5PF << CL_SEL_POS) & CL_SEL_MASK), 270 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 271 if (ret < 0) { 272 dev_err(&pdev->dev, "unable to start counter\n"); 273 return ret; 274 } 275 276 device_init_wakeup(&pdev->dev, 1); 277 278 platform_set_drvdata(pdev, rtc); 279 rtc->rtc = devm_rtc_device_register(&pdev->dev, dev_name(&pdev->dev), 280 &tps6586x_rtc_ops, THIS_MODULE); 281 if (IS_ERR(rtc->rtc)) { 282 ret = PTR_ERR(rtc->rtc); 283 dev_err(&pdev->dev, "RTC device register: ret %d\n", ret); 284 goto fail_rtc_register; 285 } 286 287 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, 288 tps6586x_rtc_irq, 289 IRQF_ONESHOT | IRQF_EARLY_RESUME, 290 dev_name(&pdev->dev), rtc); 291 if (ret < 0) { 292 dev_err(&pdev->dev, "request IRQ(%d) failed with ret %d\n", 293 rtc->irq, ret); 294 goto fail_rtc_register; 295 } 296 disable_irq(rtc->irq); 297 return 0; 298 299 fail_rtc_register: 300 tps6586x_update(tps_dev, RTC_CTRL, 0, 301 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 302 return ret; 303 }; 304 305 static int tps6586x_rtc_remove(struct platform_device *pdev) 306 { 307 struct device *tps_dev = to_tps6586x_dev(&pdev->dev); 308 309 tps6586x_update(tps_dev, RTC_CTRL, 0, 310 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 311 return 0; 312 } 313 314 #ifdef CONFIG_PM_SLEEP 315 static int tps6586x_rtc_suspend(struct device *dev) 316 { 317 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 318 319 if (device_may_wakeup(dev)) 320 enable_irq_wake(rtc->irq); 321 return 0; 322 } 323 324 static int tps6586x_rtc_resume(struct device *dev) 325 { 326 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 327 328 if (device_may_wakeup(dev)) 329 disable_irq_wake(rtc->irq); 330 return 0; 331 } 332 #endif 333 334 static SIMPLE_DEV_PM_OPS(tps6586x_pm_ops, tps6586x_rtc_suspend, 335 tps6586x_rtc_resume); 336 337 static struct platform_driver tps6586x_rtc_driver = { 338 .driver = { 339 .name = "tps6586x-rtc", 340 .pm = &tps6586x_pm_ops, 341 }, 342 .probe = tps6586x_rtc_probe, 343 .remove = tps6586x_rtc_remove, 344 }; 345 module_platform_driver(tps6586x_rtc_driver); 346 347 MODULE_ALIAS("platform:rtc-tps6586x"); 348 MODULE_DESCRIPTION("TI TPS6586x RTC driver"); 349 MODULE_AUTHOR("Laxman dewangan <ldewangan@nvidia.com>"); 350 MODULE_LICENSE("GPL v2"); 351