Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2007-2009 ST-Ericsson AB |
| 3 | * License terms: GNU General Public License (GPL) version 2 |
| 4 | * RTC clock driver for the AB3100 Analog Baseband Chip |
| 5 | * Author: Linus Walleij <linus.walleij@stericsson.com> |
| 6 | */ |
| 7 | #include <linux/module.h> |
| 8 | #include <linux/kernel.h> |
| 9 | #include <linux/init.h> |
| 10 | #include <linux/platform_device.h> |
| 11 | #include <linux/rtc.h> |
Linus Walleij | 812f9e9 | 2010-05-01 18:26:07 +0200 | [diff] [blame] | 12 | #include <linux/mfd/abx500.h> |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 13 | |
| 14 | /* Clock rate in Hz */ |
| 15 | #define AB3100_RTC_CLOCK_RATE 32768 |
| 16 | |
| 17 | /* |
| 18 | * The AB3100 RTC registers. These are the same for |
| 19 | * AB3000 and AB3100. |
| 20 | * Control register: |
| 21 | * Bit 0: RTC Monitor cleared=0, active=1, if you set it |
| 22 | * to 1 it remains active until RTC power is lost. |
| 23 | * Bit 1: 32 kHz Oscillator, 0 = on, 1 = bypass |
| 24 | * Bit 2: Alarm on, 0 = off, 1 = on |
| 25 | * Bit 3: 32 kHz buffer disabling, 0 = enabled, 1 = disabled |
| 26 | */ |
| 27 | #define AB3100_RTC 0x53 |
| 28 | /* default setting, buffer disabled, alarm on */ |
| 29 | #define RTC_SETTING 0x30 |
| 30 | /* Alarm when AL0-AL3 == TI0-TI3 */ |
| 31 | #define AB3100_AL0 0x56 |
| 32 | #define AB3100_AL1 0x57 |
| 33 | #define AB3100_AL2 0x58 |
| 34 | #define AB3100_AL3 0x59 |
| 35 | /* This 48-bit register that counts up at 32768 Hz */ |
| 36 | #define AB3100_TI0 0x5a |
| 37 | #define AB3100_TI1 0x5b |
| 38 | #define AB3100_TI2 0x5c |
| 39 | #define AB3100_TI3 0x5d |
| 40 | #define AB3100_TI4 0x5e |
| 41 | #define AB3100_TI5 0x5f |
| 42 | |
| 43 | /* |
| 44 | * RTC clock functions and device struct declaration |
| 45 | */ |
| 46 | static int ab3100_rtc_set_mmss(struct device *dev, unsigned long secs) |
| 47 | { |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 48 | u8 regs[] = {AB3100_TI0, AB3100_TI1, AB3100_TI2, |
| 49 | AB3100_TI3, AB3100_TI4, AB3100_TI5}; |
| 50 | unsigned char buf[6]; |
| 51 | u64 fat_time = (u64) secs * AB3100_RTC_CLOCK_RATE * 2; |
| 52 | int err = 0; |
| 53 | int i; |
| 54 | |
| 55 | buf[0] = (fat_time) & 0xFF; |
| 56 | buf[1] = (fat_time >> 8) & 0xFF; |
| 57 | buf[2] = (fat_time >> 16) & 0xFF; |
| 58 | buf[3] = (fat_time >> 24) & 0xFF; |
| 59 | buf[4] = (fat_time >> 32) & 0xFF; |
| 60 | buf[5] = (fat_time >> 40) & 0xFF; |
| 61 | |
| 62 | for (i = 0; i < 6; i++) { |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 63 | err = abx500_set_register_interruptible(dev, 0, |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 64 | regs[i], buf[i]); |
| 65 | if (err) |
| 66 | return err; |
| 67 | } |
| 68 | |
| 69 | /* Set the flag to mark that the clock is now set */ |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 70 | return abx500_mask_and_set_register_interruptible(dev, 0, |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 71 | AB3100_RTC, |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 72 | 0x01, 0x01); |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 73 | |
| 74 | } |
| 75 | |
| 76 | static int ab3100_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| 77 | { |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 78 | unsigned long time; |
| 79 | u8 rtcval; |
| 80 | int err; |
| 81 | |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 82 | err = abx500_get_register_interruptible(dev, 0, |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 83 | AB3100_RTC, &rtcval); |
| 84 | if (err) |
| 85 | return err; |
| 86 | |
| 87 | if (!(rtcval & 0x01)) { |
| 88 | dev_info(dev, "clock not set (lost power)"); |
| 89 | return -EINVAL; |
| 90 | } else { |
| 91 | u64 fat_time; |
| 92 | u8 buf[6]; |
| 93 | |
| 94 | /* Read out time registers */ |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 95 | err = abx500_get_register_page_interruptible(dev, 0, |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 96 | AB3100_TI0, |
| 97 | buf, 6); |
| 98 | if (err != 0) |
| 99 | return err; |
| 100 | |
| 101 | fat_time = ((u64) buf[5] << 40) | ((u64) buf[4] << 32) | |
| 102 | ((u64) buf[3] << 24) | ((u64) buf[2] << 16) | |
| 103 | ((u64) buf[1] << 8) | (u64) buf[0]; |
| 104 | time = (unsigned long) (fat_time / |
| 105 | (u64) (AB3100_RTC_CLOCK_RATE * 2)); |
| 106 | } |
| 107 | |
| 108 | rtc_time_to_tm(time, tm); |
| 109 | |
| 110 | return rtc_valid_tm(tm); |
| 111 | } |
| 112 | |
| 113 | static int ab3100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) |
| 114 | { |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 115 | unsigned long time; |
| 116 | u64 fat_time; |
| 117 | u8 buf[6]; |
| 118 | u8 rtcval; |
| 119 | int err; |
| 120 | |
| 121 | /* Figure out if alarm is enabled or not */ |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 122 | err = abx500_get_register_interruptible(dev, 0, |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 123 | AB3100_RTC, &rtcval); |
| 124 | if (err) |
| 125 | return err; |
| 126 | if (rtcval & 0x04) |
| 127 | alarm->enabled = 1; |
| 128 | else |
| 129 | alarm->enabled = 0; |
| 130 | /* No idea how this could be represented */ |
| 131 | alarm->pending = 0; |
| 132 | /* Read out alarm registers, only 4 bytes */ |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 133 | err = abx500_get_register_page_interruptible(dev, 0, |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 134 | AB3100_AL0, buf, 4); |
| 135 | if (err) |
| 136 | return err; |
| 137 | fat_time = ((u64) buf[3] << 40) | ((u64) buf[2] << 32) | |
| 138 | ((u64) buf[1] << 24) | ((u64) buf[0] << 16); |
| 139 | time = (unsigned long) (fat_time / (u64) (AB3100_RTC_CLOCK_RATE * 2)); |
| 140 | |
| 141 | rtc_time_to_tm(time, &alarm->time); |
| 142 | |
| 143 | return rtc_valid_tm(&alarm->time); |
| 144 | } |
| 145 | |
| 146 | static int ab3100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) |
| 147 | { |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 148 | u8 regs[] = {AB3100_AL0, AB3100_AL1, AB3100_AL2, AB3100_AL3}; |
| 149 | unsigned char buf[4]; |
| 150 | unsigned long secs; |
| 151 | u64 fat_time; |
| 152 | int err; |
| 153 | int i; |
| 154 | |
| 155 | rtc_tm_to_time(&alarm->time, &secs); |
| 156 | fat_time = (u64) secs * AB3100_RTC_CLOCK_RATE * 2; |
| 157 | buf[0] = (fat_time >> 16) & 0xFF; |
| 158 | buf[1] = (fat_time >> 24) & 0xFF; |
| 159 | buf[2] = (fat_time >> 32) & 0xFF; |
| 160 | buf[3] = (fat_time >> 40) & 0xFF; |
| 161 | |
| 162 | /* Set the alarm */ |
| 163 | for (i = 0; i < 4; i++) { |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 164 | err = abx500_set_register_interruptible(dev, 0, |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 165 | regs[i], buf[i]); |
| 166 | if (err) |
| 167 | return err; |
| 168 | } |
| 169 | /* Then enable the alarm */ |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 170 | return abx500_mask_and_set_register_interruptible(dev, 0, |
| 171 | AB3100_RTC, (1 << 2), |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 172 | alarm->enabled << 2); |
| 173 | } |
| 174 | |
| 175 | static int ab3100_rtc_irq_enable(struct device *dev, unsigned int enabled) |
| 176 | { |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 177 | /* |
| 178 | * It's not possible to enable/disable the alarm IRQ for this RTC. |
| 179 | * It does not actually trigger any IRQ: instead its only function is |
| 180 | * to power up the system, if it wasn't on. This will manifest as |
| 181 | * a "power up cause" in the AB3100 power driver (battery charging etc) |
| 182 | * and need to be handled there instead. |
| 183 | */ |
| 184 | if (enabled) |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 185 | return abx500_mask_and_set_register_interruptible(dev, 0, |
| 186 | AB3100_RTC, (1 << 2), |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 187 | 1 << 2); |
| 188 | else |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 189 | return abx500_mask_and_set_register_interruptible(dev, 0, |
| 190 | AB3100_RTC, (1 << 2), |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 191 | 0); |
| 192 | } |
| 193 | |
| 194 | static const struct rtc_class_ops ab3100_rtc_ops = { |
| 195 | .read_time = ab3100_rtc_read_time, |
| 196 | .set_mmss = ab3100_rtc_set_mmss, |
| 197 | .read_alarm = ab3100_rtc_read_alarm, |
| 198 | .set_alarm = ab3100_rtc_set_alarm, |
| 199 | .alarm_irq_enable = ab3100_rtc_irq_enable, |
| 200 | }; |
| 201 | |
| 202 | static int __init ab3100_rtc_probe(struct platform_device *pdev) |
| 203 | { |
| 204 | int err; |
| 205 | u8 regval; |
| 206 | struct rtc_device *rtc; |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 207 | |
| 208 | /* The first RTC register needs special treatment */ |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 209 | err = abx500_get_register_interruptible(&pdev->dev, 0, |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 210 | AB3100_RTC, ®val); |
| 211 | if (err) { |
| 212 | dev_err(&pdev->dev, "unable to read RTC register\n"); |
| 213 | return -ENODEV; |
| 214 | } |
| 215 | |
| 216 | if ((regval & 0xFE) != RTC_SETTING) { |
| 217 | dev_warn(&pdev->dev, "not default value in RTC reg 0x%x\n", |
| 218 | regval); |
| 219 | } |
| 220 | |
| 221 | if ((regval & 1) == 0) { |
| 222 | /* |
| 223 | * Set bit to detect power loss. |
| 224 | * This bit remains until RTC power is lost. |
| 225 | */ |
| 226 | regval = 1 | RTC_SETTING; |
Mattias Wallin | fa66125 | 2010-05-01 18:26:20 +0200 | [diff] [blame] | 227 | err = abx500_set_register_interruptible(&pdev->dev, 0, |
Linus Walleij | bd207cf | 2009-08-30 23:49:04 +0200 | [diff] [blame] | 228 | AB3100_RTC, regval); |
| 229 | /* Ignore any error on this write */ |
| 230 | } |
| 231 | |
| 232 | rtc = rtc_device_register("ab3100-rtc", &pdev->dev, &ab3100_rtc_ops, |
| 233 | THIS_MODULE); |
| 234 | if (IS_ERR(rtc)) { |
| 235 | err = PTR_ERR(rtc); |
| 236 | return err; |
| 237 | } |
| 238 | |
| 239 | return 0; |
| 240 | } |
| 241 | |
| 242 | static int __exit ab3100_rtc_remove(struct platform_device *pdev) |
| 243 | { |
| 244 | struct rtc_device *rtc = platform_get_drvdata(pdev); |
| 245 | |
| 246 | rtc_device_unregister(rtc); |
| 247 | return 0; |
| 248 | } |
| 249 | |
| 250 | static struct platform_driver ab3100_rtc_driver = { |
| 251 | .driver = { |
| 252 | .name = "ab3100-rtc", |
| 253 | .owner = THIS_MODULE, |
| 254 | }, |
| 255 | .remove = __exit_p(ab3100_rtc_remove), |
| 256 | }; |
| 257 | |
| 258 | static int __init ab3100_rtc_init(void) |
| 259 | { |
| 260 | return platform_driver_probe(&ab3100_rtc_driver, |
| 261 | ab3100_rtc_probe); |
| 262 | } |
| 263 | |
| 264 | static void __exit ab3100_rtc_exit(void) |
| 265 | { |
| 266 | platform_driver_unregister(&ab3100_rtc_driver); |
| 267 | } |
| 268 | |
| 269 | module_init(ab3100_rtc_init); |
| 270 | module_exit(ab3100_rtc_exit); |
| 271 | |
| 272 | MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>"); |
| 273 | MODULE_DESCRIPTION("AB3100 RTC Driver"); |
| 274 | MODULE_LICENSE("GPL"); |