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/irq.h> 27 #include <linux/kernel.h> 28 #include <linux/mfd/tps6586x.h> 29 #include <linux/module.h> 30 #include <linux/platform_device.h> 31 #include <linux/pm_runtime.h> 32 #include <linux/rtc.h> 33 #include <linux/slab.h> 34 35 #define RTC_CTRL 0xc0 36 #define POR_RESET_N BIT(7) 37 #define OSC_SRC_SEL BIT(6) 38 #define RTC_ENABLE BIT(5) /* enables alarm */ 39 #define RTC_BUF_ENABLE BIT(4) /* 32 KHz buffer enable */ 40 #define PRE_BYPASS BIT(3) /* 0=1KHz or 1=32KHz updates */ 41 #define CL_SEL_MASK (BIT(2)|BIT(1)) 42 #define CL_SEL_POS 1 43 #define RTC_ALARM1_HI 0xc1 44 #define RTC_COUNT4 0xc6 45 46 /* start a PMU RTC access by reading the register prior to the RTC_COUNT4 */ 47 #define RTC_COUNT4_DUMMYREAD 0xc5 48 49 /*only 14-bits width in second*/ 50 #define ALM1_VALID_RANGE_IN_SEC 0x3FFF 51 52 #define TPS6586X_RTC_CL_SEL_1_5PF 0x0 53 #define TPS6586X_RTC_CL_SEL_6_5PF 0x1 54 #define TPS6586X_RTC_CL_SEL_7_5PF 0x2 55 #define TPS6586X_RTC_CL_SEL_12_5PF 0x3 56 57 struct tps6586x_rtc { 58 struct device *dev; 59 struct rtc_device *rtc; 60 int irq; 61 bool irq_en; 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 device *tps_dev = to_tps6586x_dev(dev); 72 unsigned long long ticks = 0; 73 time64_t seconds; 74 u8 buff[6]; 75 int ret; 76 int i; 77 78 ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(buff), buff); 79 if (ret < 0) { 80 dev_err(dev, "read counter failed with err %d\n", ret); 81 return ret; 82 } 83 84 for (i = 1; i < sizeof(buff); i++) { 85 ticks <<= 8; 86 ticks |= buff[i]; 87 } 88 89 seconds = ticks >> 10; 90 rtc_time64_to_tm(seconds, tm); 91 92 return 0; 93 } 94 95 static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm) 96 { 97 struct device *tps_dev = to_tps6586x_dev(dev); 98 unsigned long long ticks; 99 time64_t seconds; 100 u8 buff[5]; 101 int ret; 102 103 seconds = rtc_tm_to_time64(tm); 104 105 ticks = (unsigned long long)seconds << 10; 106 buff[0] = (ticks >> 32) & 0xff; 107 buff[1] = (ticks >> 24) & 0xff; 108 buff[2] = (ticks >> 16) & 0xff; 109 buff[3] = (ticks >> 8) & 0xff; 110 buff[4] = ticks & 0xff; 111 112 /* Disable RTC before changing time */ 113 ret = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE); 114 if (ret < 0) { 115 dev_err(dev, "failed to clear RTC_ENABLE\n"); 116 return ret; 117 } 118 119 ret = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff); 120 if (ret < 0) { 121 dev_err(dev, "failed to program new time\n"); 122 return ret; 123 } 124 125 /* Enable RTC */ 126 ret = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE); 127 if (ret < 0) { 128 dev_err(dev, "failed to set RTC_ENABLE\n"); 129 return ret; 130 } 131 return 0; 132 } 133 134 static int tps6586x_rtc_alarm_irq_enable(struct device *dev, 135 unsigned int enabled) 136 { 137 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 138 139 if (enabled && !rtc->irq_en) { 140 enable_irq(rtc->irq); 141 rtc->irq_en = true; 142 } else if (!enabled && rtc->irq_en) { 143 disable_irq(rtc->irq); 144 rtc->irq_en = false; 145 } 146 return 0; 147 } 148 149 static int tps6586x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 150 { 151 struct device *tps_dev = to_tps6586x_dev(dev); 152 time64_t seconds; 153 unsigned long ticks; 154 unsigned long rtc_current_time; 155 unsigned long long rticks = 0; 156 u8 buff[3]; 157 u8 rbuff[6]; 158 int ret; 159 int i; 160 161 seconds = rtc_tm_to_time64(&alrm->time); 162 163 ret = tps6586x_rtc_alarm_irq_enable(dev, alrm->enabled); 164 if (ret < 0) { 165 dev_err(dev, "can't set alarm irq, err %d\n", ret); 166 return ret; 167 } 168 169 ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, 170 sizeof(rbuff), rbuff); 171 if (ret < 0) { 172 dev_err(dev, "read counter failed with err %d\n", ret); 173 return ret; 174 } 175 176 for (i = 1; i < sizeof(rbuff); i++) { 177 rticks <<= 8; 178 rticks |= rbuff[i]; 179 } 180 181 rtc_current_time = rticks >> 10; 182 if ((seconds - rtc_current_time) > ALM1_VALID_RANGE_IN_SEC) 183 seconds = rtc_current_time - 1; 184 185 ticks = (unsigned long long)seconds << 10; 186 buff[0] = (ticks >> 16) & 0xff; 187 buff[1] = (ticks >> 8) & 0xff; 188 buff[2] = ticks & 0xff; 189 190 ret = tps6586x_writes(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff); 191 if (ret) 192 dev_err(dev, "programming alarm failed with err %d\n", ret); 193 194 return ret; 195 } 196 197 static int tps6586x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 198 { 199 struct device *tps_dev = to_tps6586x_dev(dev); 200 unsigned long ticks; 201 time64_t seconds; 202 u8 buff[3]; 203 int ret; 204 205 ret = tps6586x_reads(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff); 206 if (ret) { 207 dev_err(dev, "read RTC_ALARM1_HI failed with err %d\n", ret); 208 return ret; 209 } 210 211 ticks = (buff[0] << 16) | (buff[1] << 8) | buff[2]; 212 seconds = ticks >> 10; 213 214 rtc_time64_to_tm(seconds, &alrm->time); 215 return 0; 216 } 217 218 static const struct rtc_class_ops tps6586x_rtc_ops = { 219 .read_time = tps6586x_rtc_read_time, 220 .set_time = tps6586x_rtc_set_time, 221 .set_alarm = tps6586x_rtc_set_alarm, 222 .read_alarm = tps6586x_rtc_read_alarm, 223 .alarm_irq_enable = tps6586x_rtc_alarm_irq_enable, 224 }; 225 226 static irqreturn_t tps6586x_rtc_irq(int irq, void *data) 227 { 228 struct tps6586x_rtc *rtc = data; 229 230 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); 231 return IRQ_HANDLED; 232 } 233 234 static int tps6586x_rtc_probe(struct platform_device *pdev) 235 { 236 struct device *tps_dev = to_tps6586x_dev(&pdev->dev); 237 struct tps6586x_rtc *rtc; 238 int ret; 239 240 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); 241 if (!rtc) 242 return -ENOMEM; 243 244 rtc->dev = &pdev->dev; 245 rtc->irq = platform_get_irq(pdev, 0); 246 247 /* 1 kHz tick mode, enable tick counting */ 248 ret = tps6586x_update(tps_dev, RTC_CTRL, 249 RTC_ENABLE | OSC_SRC_SEL | 250 ((TPS6586X_RTC_CL_SEL_1_5PF << CL_SEL_POS) & CL_SEL_MASK), 251 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 252 if (ret < 0) { 253 dev_err(&pdev->dev, "unable to start counter\n"); 254 return ret; 255 } 256 257 device_init_wakeup(&pdev->dev, 1); 258 259 platform_set_drvdata(pdev, rtc); 260 rtc->rtc = devm_rtc_allocate_device(&pdev->dev); 261 if (IS_ERR(rtc->rtc)) { 262 ret = PTR_ERR(rtc->rtc); 263 goto fail_rtc_register; 264 } 265 266 rtc->rtc->ops = &tps6586x_rtc_ops; 267 rtc->rtc->range_max = (1ULL << 30) - 1; /* 30-bit seconds */ 268 rtc->rtc->start_secs = mktime64(2009, 1, 1, 0, 0, 0); 269 rtc->rtc->set_start_time = true; 270 271 irq_set_status_flags(rtc->irq, IRQ_NOAUTOEN); 272 273 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, 274 tps6586x_rtc_irq, 275 IRQF_ONESHOT, 276 dev_name(&pdev->dev), rtc); 277 if (ret < 0) { 278 dev_err(&pdev->dev, "request IRQ(%d) failed with ret %d\n", 279 rtc->irq, ret); 280 goto fail_rtc_register; 281 } 282 283 ret = rtc_register_device(rtc->rtc); 284 if (ret) 285 goto fail_rtc_register; 286 287 return 0; 288 289 fail_rtc_register: 290 tps6586x_update(tps_dev, RTC_CTRL, 0, 291 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 292 return ret; 293 }; 294 295 static int tps6586x_rtc_remove(struct platform_device *pdev) 296 { 297 struct device *tps_dev = to_tps6586x_dev(&pdev->dev); 298 299 tps6586x_update(tps_dev, RTC_CTRL, 0, 300 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 301 return 0; 302 } 303 304 #ifdef CONFIG_PM_SLEEP 305 static int tps6586x_rtc_suspend(struct device *dev) 306 { 307 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 308 309 if (device_may_wakeup(dev)) 310 enable_irq_wake(rtc->irq); 311 return 0; 312 } 313 314 static int tps6586x_rtc_resume(struct device *dev) 315 { 316 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 317 318 if (device_may_wakeup(dev)) 319 disable_irq_wake(rtc->irq); 320 return 0; 321 } 322 #endif 323 324 static SIMPLE_DEV_PM_OPS(tps6586x_pm_ops, tps6586x_rtc_suspend, 325 tps6586x_rtc_resume); 326 327 static struct platform_driver tps6586x_rtc_driver = { 328 .driver = { 329 .name = "tps6586x-rtc", 330 .pm = &tps6586x_pm_ops, 331 }, 332 .probe = tps6586x_rtc_probe, 333 .remove = tps6586x_rtc_remove, 334 }; 335 module_platform_driver(tps6586x_rtc_driver); 336 337 MODULE_ALIAS("platform:tps6586x-rtc"); 338 MODULE_DESCRIPTION("TI TPS6586x RTC driver"); 339 MODULE_AUTHOR("Laxman dewangan <ldewangan@nvidia.com>"); 340 MODULE_LICENSE("GPL v2"); 341