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 }; 62 63 static inline struct device *to_tps6586x_dev(struct device *dev) 64 { 65 return dev->parent; 66 } 67 68 static int tps6586x_rtc_read_time(struct device *dev, struct rtc_time *tm) 69 { 70 struct device *tps_dev = to_tps6586x_dev(dev); 71 unsigned long long ticks = 0; 72 time64_t seconds; 73 u8 buff[6]; 74 int ret; 75 int i; 76 77 ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(buff), buff); 78 if (ret < 0) { 79 dev_err(dev, "read counter failed with err %d\n", ret); 80 return ret; 81 } 82 83 for (i = 1; i < sizeof(buff); i++) { 84 ticks <<= 8; 85 ticks |= buff[i]; 86 } 87 88 seconds = ticks >> 10; 89 rtc_time64_to_tm(seconds, tm); 90 91 return 0; 92 } 93 94 static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm) 95 { 96 struct device *tps_dev = to_tps6586x_dev(dev); 97 unsigned long long ticks; 98 time64_t seconds; 99 u8 buff[5]; 100 int ret; 101 102 seconds = rtc_tm_to_time64(tm); 103 104 ticks = (unsigned long long)seconds << 10; 105 buff[0] = (ticks >> 32) & 0xff; 106 buff[1] = (ticks >> 24) & 0xff; 107 buff[2] = (ticks >> 16) & 0xff; 108 buff[3] = (ticks >> 8) & 0xff; 109 buff[4] = ticks & 0xff; 110 111 /* Disable RTC before changing time */ 112 ret = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE); 113 if (ret < 0) { 114 dev_err(dev, "failed to clear RTC_ENABLE\n"); 115 return ret; 116 } 117 118 ret = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff); 119 if (ret < 0) { 120 dev_err(dev, "failed to program new time\n"); 121 return ret; 122 } 123 124 /* Enable RTC */ 125 ret = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE); 126 if (ret < 0) { 127 dev_err(dev, "failed to set RTC_ENABLE\n"); 128 return ret; 129 } 130 return 0; 131 } 132 133 static int tps6586x_rtc_alarm_irq_enable(struct device *dev, 134 unsigned int enabled) 135 { 136 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 137 138 if (enabled && !rtc->irq_en) { 139 enable_irq(rtc->irq); 140 rtc->irq_en = true; 141 } else if (!enabled && rtc->irq_en) { 142 disable_irq(rtc->irq); 143 rtc->irq_en = false; 144 } 145 return 0; 146 } 147 148 static int tps6586x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 149 { 150 struct device *tps_dev = to_tps6586x_dev(dev); 151 time64_t seconds; 152 unsigned long ticks; 153 unsigned long rtc_current_time; 154 unsigned long long rticks = 0; 155 u8 buff[3]; 156 u8 rbuff[6]; 157 int ret; 158 int i; 159 160 seconds = rtc_tm_to_time64(&alrm->time); 161 162 ret = tps6586x_rtc_alarm_irq_enable(dev, alrm->enabled); 163 if (ret < 0) { 164 dev_err(dev, "can't set alarm irq, err %d\n", ret); 165 return ret; 166 } 167 168 ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, 169 sizeof(rbuff), rbuff); 170 if (ret < 0) { 171 dev_err(dev, "read counter failed with err %d\n", ret); 172 return ret; 173 } 174 175 for (i = 1; i < sizeof(rbuff); i++) { 176 rticks <<= 8; 177 rticks |= rbuff[i]; 178 } 179 180 rtc_current_time = rticks >> 10; 181 if ((seconds - rtc_current_time) > ALM1_VALID_RANGE_IN_SEC) 182 seconds = rtc_current_time - 1; 183 184 ticks = (unsigned long long)seconds << 10; 185 buff[0] = (ticks >> 16) & 0xff; 186 buff[1] = (ticks >> 8) & 0xff; 187 buff[2] = ticks & 0xff; 188 189 ret = tps6586x_writes(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff); 190 if (ret) 191 dev_err(dev, "programming alarm failed with err %d\n", ret); 192 193 return ret; 194 } 195 196 static int tps6586x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 197 { 198 struct device *tps_dev = to_tps6586x_dev(dev); 199 unsigned long ticks; 200 time64_t seconds; 201 u8 buff[3]; 202 int ret; 203 204 ret = tps6586x_reads(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff); 205 if (ret) { 206 dev_err(dev, "read RTC_ALARM1_HI failed with err %d\n", ret); 207 return ret; 208 } 209 210 ticks = (buff[0] << 16) | (buff[1] << 8) | buff[2]; 211 seconds = ticks >> 10; 212 213 rtc_time64_to_tm(seconds, &alrm->time); 214 return 0; 215 } 216 217 static const struct rtc_class_ops tps6586x_rtc_ops = { 218 .read_time = tps6586x_rtc_read_time, 219 .set_time = tps6586x_rtc_set_time, 220 .set_alarm = tps6586x_rtc_set_alarm, 221 .read_alarm = tps6586x_rtc_read_alarm, 222 .alarm_irq_enable = tps6586x_rtc_alarm_irq_enable, 223 }; 224 225 static irqreturn_t tps6586x_rtc_irq(int irq, void *data) 226 { 227 struct tps6586x_rtc *rtc = data; 228 229 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); 230 return IRQ_HANDLED; 231 } 232 233 static int tps6586x_rtc_probe(struct platform_device *pdev) 234 { 235 struct device *tps_dev = to_tps6586x_dev(&pdev->dev); 236 struct tps6586x_rtc *rtc; 237 int ret; 238 239 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); 240 if (!rtc) 241 return -ENOMEM; 242 243 rtc->dev = &pdev->dev; 244 rtc->irq = platform_get_irq(pdev, 0); 245 246 /* 1 kHz tick mode, enable tick counting */ 247 ret = tps6586x_update(tps_dev, RTC_CTRL, 248 RTC_ENABLE | OSC_SRC_SEL | 249 ((TPS6586X_RTC_CL_SEL_1_5PF << CL_SEL_POS) & CL_SEL_MASK), 250 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 251 if (ret < 0) { 252 dev_err(&pdev->dev, "unable to start counter\n"); 253 return ret; 254 } 255 256 device_init_wakeup(&pdev->dev, 1); 257 258 platform_set_drvdata(pdev, rtc); 259 rtc->rtc = devm_rtc_allocate_device(&pdev->dev); 260 if (IS_ERR(rtc->rtc)) { 261 ret = PTR_ERR(rtc->rtc); 262 goto fail_rtc_register; 263 } 264 265 rtc->rtc->ops = &tps6586x_rtc_ops; 266 rtc->rtc->range_max = (1ULL << 30) - 1; /* 30-bit seconds */ 267 rtc->rtc->start_secs = mktime64(2009, 1, 1, 0, 0, 0); 268 rtc->rtc->set_start_time = true; 269 270 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, 271 tps6586x_rtc_irq, 272 IRQF_ONESHOT, 273 dev_name(&pdev->dev), rtc); 274 if (ret < 0) { 275 dev_err(&pdev->dev, "request IRQ(%d) failed with ret %d\n", 276 rtc->irq, ret); 277 goto fail_rtc_register; 278 } 279 disable_irq(rtc->irq); 280 281 ret = rtc_register_device(rtc->rtc); 282 if (ret) 283 goto fail_rtc_register; 284 285 return 0; 286 287 fail_rtc_register: 288 tps6586x_update(tps_dev, RTC_CTRL, 0, 289 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 290 return ret; 291 }; 292 293 static int tps6586x_rtc_remove(struct platform_device *pdev) 294 { 295 struct device *tps_dev = to_tps6586x_dev(&pdev->dev); 296 297 tps6586x_update(tps_dev, RTC_CTRL, 0, 298 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 299 return 0; 300 } 301 302 #ifdef CONFIG_PM_SLEEP 303 static int tps6586x_rtc_suspend(struct device *dev) 304 { 305 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 306 307 if (device_may_wakeup(dev)) 308 enable_irq_wake(rtc->irq); 309 return 0; 310 } 311 312 static int tps6586x_rtc_resume(struct device *dev) 313 { 314 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 315 316 if (device_may_wakeup(dev)) 317 disable_irq_wake(rtc->irq); 318 return 0; 319 } 320 #endif 321 322 static SIMPLE_DEV_PM_OPS(tps6586x_pm_ops, tps6586x_rtc_suspend, 323 tps6586x_rtc_resume); 324 325 static struct platform_driver tps6586x_rtc_driver = { 326 .driver = { 327 .name = "tps6586x-rtc", 328 .pm = &tps6586x_pm_ops, 329 }, 330 .probe = tps6586x_rtc_probe, 331 .remove = tps6586x_rtc_remove, 332 }; 333 module_platform_driver(tps6586x_rtc_driver); 334 335 MODULE_ALIAS("platform:tps6586x-rtc"); 336 MODULE_DESCRIPTION("TI TPS6586x RTC driver"); 337 MODULE_AUTHOR("Laxman dewangan <ldewangan@nvidia.com>"); 338 MODULE_LICENSE("GPL v2"); 339