Stephen Warren | 94c01ab | 2012-10-04 17:13:56 -0700 | [diff] [blame] | 1 | /* |
| 2 | * RTC driver for Maxim MAX8907 |
| 3 | * |
| 4 | * Copyright (c) 2011-2012, NVIDIA Corporation. |
| 5 | * |
| 6 | * Based on drivers/rtc/rtc-max8925.c, |
| 7 | * Copyright (C) 2009-2010 Marvell International Ltd. |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 as |
| 11 | * published by the Free Software Foundation. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/bcd.h> |
| 15 | #include <linux/i2c.h> |
| 16 | #include <linux/mfd/max8907.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/platform_device.h> |
| 19 | #include <linux/regmap.h> |
| 20 | #include <linux/rtc.h> |
| 21 | #include <linux/slab.h> |
| 22 | |
| 23 | enum { |
| 24 | RTC_SEC = 0, |
| 25 | RTC_MIN, |
| 26 | RTC_HOUR, |
| 27 | RTC_WEEKDAY, |
| 28 | RTC_DATE, |
| 29 | RTC_MONTH, |
| 30 | RTC_YEAR1, |
| 31 | RTC_YEAR2, |
| 32 | }; |
| 33 | |
| 34 | #define TIME_NUM 8 |
| 35 | #define ALARM_1SEC (1 << 7) |
| 36 | #define HOUR_12 (1 << 7) |
| 37 | #define HOUR_AM_PM (1 << 5) |
| 38 | #define ALARM0_IRQ (1 << 3) |
| 39 | #define ALARM1_IRQ (1 << 2) |
| 40 | #define ALARM0_STATUS (1 << 2) |
| 41 | #define ALARM1_STATUS (1 << 1) |
| 42 | |
| 43 | struct max8907_rtc { |
| 44 | struct max8907 *max8907; |
| 45 | struct regmap *regmap; |
| 46 | struct rtc_device *rtc_dev; |
| 47 | int irq; |
| 48 | }; |
| 49 | |
| 50 | static irqreturn_t max8907_irq_handler(int irq, void *data) |
| 51 | { |
| 52 | struct max8907_rtc *rtc = data; |
| 53 | |
| 54 | regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x7f, 0); |
| 55 | |
| 56 | rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF); |
| 57 | |
| 58 | return IRQ_HANDLED; |
| 59 | } |
| 60 | |
| 61 | static void regs_to_tm(u8 *regs, struct rtc_time *tm) |
| 62 | { |
| 63 | tm->tm_year = bcd2bin(regs[RTC_YEAR2]) * 100 + |
| 64 | bcd2bin(regs[RTC_YEAR1]) - 1900; |
| 65 | tm->tm_mon = bcd2bin(regs[RTC_MONTH] & 0x1f) - 1; |
| 66 | tm->tm_mday = bcd2bin(regs[RTC_DATE] & 0x3f); |
| 67 | tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07) - 1; |
| 68 | if (regs[RTC_HOUR] & HOUR_12) { |
| 69 | tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x01f); |
| 70 | if (tm->tm_hour == 12) |
| 71 | tm->tm_hour = 0; |
| 72 | if (regs[RTC_HOUR] & HOUR_AM_PM) |
| 73 | tm->tm_hour += 12; |
| 74 | } else { |
| 75 | tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x03f); |
| 76 | } |
| 77 | tm->tm_min = bcd2bin(regs[RTC_MIN] & 0x7f); |
| 78 | tm->tm_sec = bcd2bin(regs[RTC_SEC] & 0x7f); |
| 79 | } |
| 80 | |
| 81 | static void tm_to_regs(struct rtc_time *tm, u8 *regs) |
| 82 | { |
| 83 | u8 high, low; |
| 84 | |
| 85 | high = (tm->tm_year + 1900) / 100; |
| 86 | low = tm->tm_year % 100; |
| 87 | regs[RTC_YEAR2] = bin2bcd(high); |
| 88 | regs[RTC_YEAR1] = bin2bcd(low); |
| 89 | regs[RTC_MONTH] = bin2bcd(tm->tm_mon + 1); |
| 90 | regs[RTC_DATE] = bin2bcd(tm->tm_mday); |
| 91 | regs[RTC_WEEKDAY] = tm->tm_wday + 1; |
| 92 | regs[RTC_HOUR] = bin2bcd(tm->tm_hour); |
| 93 | regs[RTC_MIN] = bin2bcd(tm->tm_min); |
| 94 | regs[RTC_SEC] = bin2bcd(tm->tm_sec); |
| 95 | } |
| 96 | |
| 97 | static int max8907_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| 98 | { |
| 99 | struct max8907_rtc *rtc = dev_get_drvdata(dev); |
| 100 | u8 regs[TIME_NUM]; |
| 101 | int ret; |
| 102 | |
| 103 | ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_RTC_SEC, regs, |
| 104 | TIME_NUM); |
| 105 | if (ret < 0) |
| 106 | return ret; |
| 107 | |
| 108 | regs_to_tm(regs, tm); |
| 109 | |
| 110 | return 0; |
| 111 | } |
| 112 | |
| 113 | static int max8907_rtc_set_time(struct device *dev, struct rtc_time *tm) |
| 114 | { |
| 115 | struct max8907_rtc *rtc = dev_get_drvdata(dev); |
| 116 | u8 regs[TIME_NUM]; |
| 117 | |
| 118 | tm_to_regs(tm, regs); |
| 119 | |
| 120 | return regmap_bulk_write(rtc->regmap, MAX8907_REG_RTC_SEC, regs, |
| 121 | TIME_NUM); |
| 122 | } |
| 123 | |
| 124 | static int max8907_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
| 125 | { |
| 126 | struct max8907_rtc *rtc = dev_get_drvdata(dev); |
| 127 | u8 regs[TIME_NUM]; |
| 128 | unsigned int val; |
| 129 | int ret; |
| 130 | |
| 131 | ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs, |
| 132 | TIME_NUM); |
| 133 | if (ret < 0) |
| 134 | return ret; |
| 135 | |
| 136 | regs_to_tm(regs, &alrm->time); |
| 137 | |
| 138 | ret = regmap_read(rtc->regmap, MAX8907_REG_ALARM0_CNTL, &val); |
| 139 | if (ret < 0) |
| 140 | return ret; |
| 141 | |
| 142 | alrm->enabled = !!(val & 0x7f); |
| 143 | |
| 144 | return 0; |
| 145 | } |
| 146 | |
| 147 | static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
| 148 | { |
| 149 | struct max8907_rtc *rtc = dev_get_drvdata(dev); |
| 150 | u8 regs[TIME_NUM]; |
| 151 | int ret; |
| 152 | |
| 153 | tm_to_regs(&alrm->time, regs); |
| 154 | |
| 155 | /* Disable alarm while we update the target time */ |
| 156 | ret = regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x7f, 0); |
| 157 | if (ret < 0) |
| 158 | return ret; |
| 159 | |
| 160 | ret = regmap_bulk_write(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs, |
| 161 | TIME_NUM); |
| 162 | if (ret < 0) |
| 163 | return ret; |
| 164 | |
| 165 | if (alrm->enabled) |
| 166 | ret = regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL, |
| 167 | 0x7f, 0x7f); |
| 168 | |
| 169 | return ret; |
| 170 | } |
| 171 | |
| 172 | static const struct rtc_class_ops max8907_rtc_ops = { |
| 173 | .read_time = max8907_rtc_read_time, |
| 174 | .set_time = max8907_rtc_set_time, |
| 175 | .read_alarm = max8907_rtc_read_alarm, |
| 176 | .set_alarm = max8907_rtc_set_alarm, |
| 177 | }; |
| 178 | |
| 179 | static int __devinit max8907_rtc_probe(struct platform_device *pdev) |
| 180 | { |
| 181 | struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent); |
| 182 | struct max8907_rtc *rtc; |
| 183 | int ret; |
| 184 | |
| 185 | rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); |
| 186 | if (!rtc) |
| 187 | return -ENOMEM; |
| 188 | platform_set_drvdata(pdev, rtc); |
| 189 | |
| 190 | rtc->max8907 = max8907; |
| 191 | rtc->regmap = max8907->regmap_rtc; |
| 192 | |
| 193 | rtc->rtc_dev = rtc_device_register("max8907-rtc", &pdev->dev, |
| 194 | &max8907_rtc_ops, THIS_MODULE); |
| 195 | if (IS_ERR(rtc->rtc_dev)) { |
| 196 | ret = PTR_ERR(rtc->rtc_dev); |
| 197 | dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); |
| 198 | return ret; |
| 199 | } |
| 200 | |
| 201 | rtc->irq = regmap_irq_get_virq(max8907->irqc_rtc, |
| 202 | MAX8907_IRQ_RTC_ALARM0); |
| 203 | if (rtc->irq < 0) { |
| 204 | ret = rtc->irq; |
| 205 | goto err_unregister; |
| 206 | } |
| 207 | |
| 208 | ret = request_threaded_irq(rtc->irq, NULL, max8907_irq_handler, |
| 209 | IRQF_ONESHOT, "max8907-alarm0", rtc); |
| 210 | if (ret < 0) { |
| 211 | dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n", |
| 212 | rtc->irq, ret); |
| 213 | goto err_unregister; |
| 214 | } |
| 215 | |
| 216 | return 0; |
| 217 | |
| 218 | err_unregister: |
| 219 | rtc_device_unregister(rtc->rtc_dev); |
| 220 | return ret; |
| 221 | } |
| 222 | |
| 223 | static int __devexit max8907_rtc_remove(struct platform_device *pdev) |
| 224 | { |
| 225 | struct max8907_rtc *rtc = platform_get_drvdata(pdev); |
| 226 | |
| 227 | free_irq(rtc->irq, rtc); |
| 228 | rtc_device_unregister(rtc->rtc_dev); |
| 229 | |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | static struct platform_driver max8907_rtc_driver = { |
| 234 | .driver = { |
| 235 | .name = "max8907-rtc", |
| 236 | .owner = THIS_MODULE, |
| 237 | }, |
| 238 | .probe = max8907_rtc_probe, |
| 239 | .remove = __devexit_p(max8907_rtc_remove), |
| 240 | }; |
| 241 | module_platform_driver(max8907_rtc_driver); |
| 242 | |
| 243 | MODULE_DESCRIPTION("Maxim MAX8907 RTC driver"); |
| 244 | MODULE_LICENSE("GPL v2"); |