1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * rtc-tps6586x.c: RTC driver for TI PMIC TPS6586X 4 * 5 * Copyright (c) 2012, NVIDIA Corporation. 6 * 7 * Author: Laxman Dewangan <ldewangan@nvidia.com> 8 */ 9 10 #include <linux/device.h> 11 #include <linux/err.h> 12 #include <linux/init.h> 13 #include <linux/irq.h> 14 #include <linux/kernel.h> 15 #include <linux/mfd/tps6586x.h> 16 #include <linux/module.h> 17 #include <linux/platform_device.h> 18 #include <linux/pm_runtime.h> 19 #include <linux/rtc.h> 20 #include <linux/slab.h> 21 22 #define RTC_CTRL 0xc0 23 #define POR_RESET_N BIT(7) 24 #define OSC_SRC_SEL BIT(6) 25 #define RTC_ENABLE BIT(5) /* enables alarm */ 26 #define RTC_BUF_ENABLE BIT(4) /* 32 KHz buffer enable */ 27 #define PRE_BYPASS BIT(3) /* 0=1KHz or 1=32KHz updates */ 28 #define CL_SEL_MASK (BIT(2)|BIT(1)) 29 #define CL_SEL_POS 1 30 #define RTC_ALARM1_HI 0xc1 31 #define RTC_COUNT4 0xc6 32 33 /* start a PMU RTC access by reading the register prior to the RTC_COUNT4 */ 34 #define RTC_COUNT4_DUMMYREAD 0xc5 35 36 /*only 14-bits width in second*/ 37 #define ALM1_VALID_RANGE_IN_SEC 0x3FFF 38 39 #define TPS6586X_RTC_CL_SEL_1_5PF 0x0 40 #define TPS6586X_RTC_CL_SEL_6_5PF 0x1 41 #define TPS6586X_RTC_CL_SEL_7_5PF 0x2 42 #define TPS6586X_RTC_CL_SEL_12_5PF 0x3 43 44 struct tps6586x_rtc { 45 struct device *dev; 46 struct rtc_device *rtc; 47 int irq; 48 bool irq_en; 49 }; 50 51 static inline struct device *to_tps6586x_dev(struct device *dev) 52 { 53 return dev->parent; 54 } 55 56 static int tps6586x_rtc_read_time(struct device *dev, struct rtc_time *tm) 57 { 58 struct device *tps_dev = to_tps6586x_dev(dev); 59 unsigned long long ticks = 0; 60 time64_t seconds; 61 u8 buff[6]; 62 int ret; 63 int i; 64 65 ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(buff), buff); 66 if (ret < 0) { 67 dev_err(dev, "read counter failed with err %d\n", ret); 68 return ret; 69 } 70 71 for (i = 1; i < sizeof(buff); i++) { 72 ticks <<= 8; 73 ticks |= buff[i]; 74 } 75 76 seconds = ticks >> 10; 77 rtc_time64_to_tm(seconds, tm); 78 79 return 0; 80 } 81 82 static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm) 83 { 84 struct device *tps_dev = to_tps6586x_dev(dev); 85 unsigned long long ticks; 86 time64_t seconds; 87 u8 buff[5]; 88 int ret; 89 90 seconds = rtc_tm_to_time64(tm); 91 92 ticks = (unsigned long long)seconds << 10; 93 buff[0] = (ticks >> 32) & 0xff; 94 buff[1] = (ticks >> 24) & 0xff; 95 buff[2] = (ticks >> 16) & 0xff; 96 buff[3] = (ticks >> 8) & 0xff; 97 buff[4] = ticks & 0xff; 98 99 /* Disable RTC before changing time */ 100 ret = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE); 101 if (ret < 0) { 102 dev_err(dev, "failed to clear RTC_ENABLE\n"); 103 return ret; 104 } 105 106 ret = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff); 107 if (ret < 0) { 108 dev_err(dev, "failed to program new time\n"); 109 return ret; 110 } 111 112 /* Enable RTC */ 113 ret = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE); 114 if (ret < 0) { 115 dev_err(dev, "failed to set RTC_ENABLE\n"); 116 return ret; 117 } 118 return 0; 119 } 120 121 static int tps6586x_rtc_alarm_irq_enable(struct device *dev, 122 unsigned int enabled) 123 { 124 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 125 126 if (enabled && !rtc->irq_en) { 127 enable_irq(rtc->irq); 128 rtc->irq_en = true; 129 } else if (!enabled && rtc->irq_en) { 130 disable_irq(rtc->irq); 131 rtc->irq_en = false; 132 } 133 return 0; 134 } 135 136 static int tps6586x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 137 { 138 struct device *tps_dev = to_tps6586x_dev(dev); 139 time64_t seconds; 140 unsigned long ticks; 141 unsigned long rtc_current_time; 142 unsigned long long rticks = 0; 143 u8 buff[3]; 144 u8 rbuff[6]; 145 int ret; 146 int i; 147 148 seconds = rtc_tm_to_time64(&alrm->time); 149 150 ret = tps6586x_rtc_alarm_irq_enable(dev, alrm->enabled); 151 if (ret < 0) { 152 dev_err(dev, "can't set alarm irq, err %d\n", ret); 153 return ret; 154 } 155 156 ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, 157 sizeof(rbuff), rbuff); 158 if (ret < 0) { 159 dev_err(dev, "read counter failed with err %d\n", ret); 160 return ret; 161 } 162 163 for (i = 1; i < sizeof(rbuff); i++) { 164 rticks <<= 8; 165 rticks |= rbuff[i]; 166 } 167 168 rtc_current_time = rticks >> 10; 169 if ((seconds - rtc_current_time) > ALM1_VALID_RANGE_IN_SEC) 170 seconds = rtc_current_time - 1; 171 172 ticks = (unsigned long long)seconds << 10; 173 buff[0] = (ticks >> 16) & 0xff; 174 buff[1] = (ticks >> 8) & 0xff; 175 buff[2] = ticks & 0xff; 176 177 ret = tps6586x_writes(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff); 178 if (ret) 179 dev_err(dev, "programming alarm failed with err %d\n", ret); 180 181 return ret; 182 } 183 184 static int tps6586x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 185 { 186 struct device *tps_dev = to_tps6586x_dev(dev); 187 unsigned long ticks; 188 time64_t seconds; 189 u8 buff[3]; 190 int ret; 191 192 ret = tps6586x_reads(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff); 193 if (ret) { 194 dev_err(dev, "read RTC_ALARM1_HI failed with err %d\n", ret); 195 return ret; 196 } 197 198 ticks = (buff[0] << 16) | (buff[1] << 8) | buff[2]; 199 seconds = ticks >> 10; 200 201 rtc_time64_to_tm(seconds, &alrm->time); 202 return 0; 203 } 204 205 static const struct rtc_class_ops tps6586x_rtc_ops = { 206 .read_time = tps6586x_rtc_read_time, 207 .set_time = tps6586x_rtc_set_time, 208 .set_alarm = tps6586x_rtc_set_alarm, 209 .read_alarm = tps6586x_rtc_read_alarm, 210 .alarm_irq_enable = tps6586x_rtc_alarm_irq_enable, 211 }; 212 213 static irqreturn_t tps6586x_rtc_irq(int irq, void *data) 214 { 215 struct tps6586x_rtc *rtc = data; 216 217 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); 218 return IRQ_HANDLED; 219 } 220 221 static int tps6586x_rtc_probe(struct platform_device *pdev) 222 { 223 struct device *tps_dev = to_tps6586x_dev(&pdev->dev); 224 struct tps6586x_rtc *rtc; 225 int ret; 226 227 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); 228 if (!rtc) 229 return -ENOMEM; 230 231 rtc->dev = &pdev->dev; 232 rtc->irq = platform_get_irq(pdev, 0); 233 234 /* 1 kHz tick mode, enable tick counting */ 235 ret = tps6586x_update(tps_dev, RTC_CTRL, 236 RTC_ENABLE | OSC_SRC_SEL | 237 ((TPS6586X_RTC_CL_SEL_1_5PF << CL_SEL_POS) & CL_SEL_MASK), 238 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 239 if (ret < 0) { 240 dev_err(&pdev->dev, "unable to start counter\n"); 241 return ret; 242 } 243 244 device_init_wakeup(&pdev->dev, 1); 245 246 platform_set_drvdata(pdev, rtc); 247 rtc->rtc = devm_rtc_allocate_device(&pdev->dev); 248 if (IS_ERR(rtc->rtc)) { 249 ret = PTR_ERR(rtc->rtc); 250 goto fail_rtc_register; 251 } 252 253 rtc->rtc->ops = &tps6586x_rtc_ops; 254 rtc->rtc->range_max = (1ULL << 30) - 1; /* 30-bit seconds */ 255 rtc->rtc->start_secs = mktime64(2009, 1, 1, 0, 0, 0); 256 rtc->rtc->set_start_time = true; 257 258 irq_set_status_flags(rtc->irq, IRQ_NOAUTOEN); 259 260 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, 261 tps6586x_rtc_irq, 262 IRQF_ONESHOT, 263 dev_name(&pdev->dev), rtc); 264 if (ret < 0) { 265 dev_err(&pdev->dev, "request IRQ(%d) failed with ret %d\n", 266 rtc->irq, ret); 267 goto fail_rtc_register; 268 } 269 270 ret = devm_rtc_register_device(rtc->rtc); 271 if (ret) 272 goto fail_rtc_register; 273 274 return 0; 275 276 fail_rtc_register: 277 tps6586x_update(tps_dev, RTC_CTRL, 0, 278 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 279 return ret; 280 }; 281 282 static void tps6586x_rtc_remove(struct platform_device *pdev) 283 { 284 struct device *tps_dev = to_tps6586x_dev(&pdev->dev); 285 286 tps6586x_update(tps_dev, RTC_CTRL, 0, 287 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK); 288 } 289 290 #ifdef CONFIG_PM_SLEEP 291 static int tps6586x_rtc_suspend(struct device *dev) 292 { 293 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 294 295 if (device_may_wakeup(dev)) 296 enable_irq_wake(rtc->irq); 297 return 0; 298 } 299 300 static int tps6586x_rtc_resume(struct device *dev) 301 { 302 struct tps6586x_rtc *rtc = dev_get_drvdata(dev); 303 304 if (device_may_wakeup(dev)) 305 disable_irq_wake(rtc->irq); 306 return 0; 307 } 308 #endif 309 310 static SIMPLE_DEV_PM_OPS(tps6586x_pm_ops, tps6586x_rtc_suspend, 311 tps6586x_rtc_resume); 312 313 static struct platform_driver tps6586x_rtc_driver = { 314 .driver = { 315 .name = "tps6586x-rtc", 316 .pm = &tps6586x_pm_ops, 317 }, 318 .probe = tps6586x_rtc_probe, 319 .remove_new = tps6586x_rtc_remove, 320 }; 321 module_platform_driver(tps6586x_rtc_driver); 322 323 MODULE_ALIAS("platform:tps6586x-rtc"); 324 MODULE_DESCRIPTION("TI TPS6586x RTC driver"); 325 MODULE_AUTHOR("Laxman dewangan <ldewangan@nvidia.com>"); 326 MODULE_LICENSE("GPL v2"); 327