diff options
Diffstat (limited to 'drivers/rtc/rtc-ab.c')
| -rw-r--r-- | drivers/rtc/rtc-ab.c | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ab.c b/drivers/rtc/rtc-ab.c new file mode 100644 index 00000000000..3d3c216995d --- /dev/null +++ b/drivers/rtc/rtc-ab.c @@ -0,0 +1,480 @@ +/* + * Copyright (C) ST-Ericsson SA 2011 + * + * License terms: GNU General Public License (GPL) version 2 + * Author: Rabin Vincent <rabin.vincent@stericsson.com> + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/mfd/abx500.h> + +#define AB5500_RTC_CLOCK_RATE 32768 +#define AB5500_RTC 0x00 +#define AB5500_RTC_ALARM (1 << 1) +#define AB5500_READREQ 0x01 +#define AB5500_READREQ_REQ 0x01 +#define AB5500_AL0 0x02 +#define AB5500_TI0 0x06 + +/** + * struct ab_rtc - variant specific data + * @irqname: optional name for the alarm interrupt resource + * @epoch: epoch to adjust year to + * @bank: AB bank where this block is present + * @rtc: address of the "RTC" (control) register + * @rtc_alarmon: mask of the alarm enable bit in the above register + * @ti0: address of the TI0 register. The rest of the TI + * registers are assumed to contiguously follow this one. + * @nr_ti: number of TI* registers + * @al0: address of the AL0 register. The rest of the + * AL registers are assumed to contiguously follow this one. + * @nr_al: number of AL* registers + * @startup: optional function to initialize the RTC + * @alarm_to_regs: function to convert alarm time in seconds + * to a list of AL register values + * @time_to_regs: function to convert alarm time in seconds + * to a list of TI register values + * @regs_to_alarm: function to convert a list of AL register + * values to the alarm time in seconds + * @regs_to_time: function to convert a list of TI register + * values to the alarm time in seconds + * @request_read: optional function to request a read from the TI* registers + * @request_write: optional function to request a write to the TI* registers + */ +struct ab_rtc { + const char *irqname; + unsigned int epoch; + + u8 bank; + u8 rtc; + u8 rtc_alarmon; + u8 ti0; + int nr_ti; + u8 al0; + int nr_al; + + int (*startup)(struct device *dev); + void (*alarm_to_regs)(struct device *dev, unsigned long secs, u8 *regs); + void (*time_to_regs)(struct device *dev, unsigned long secs, u8 *regs); + unsigned long (*regs_to_alarm)(struct device *dev, u8 *regs); + unsigned long (*regs_to_time)(struct device *dev, u8 *regs); + int (*request_read)(struct device *dev); + int (*request_write)(struct device *dev); +}; + +static const struct ab_rtc *to_ab_rtc(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + return (struct ab_rtc *)pdev->id_entry->driver_data; +} + +/* Calculate the number of seconds since year, for epoch adjustment */ +static unsigned long ab_rtc_get_elapsed_seconds(unsigned int year) +{ + unsigned long secs; + struct rtc_time tm = { + .tm_year = year - 1900, + .tm_mday = 1, + }; + + rtc_tm_to_time(&tm, &secs); + + return secs; +} + +static int ab5500_rtc_request_read(struct device *dev) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + unsigned long timeout; + int err; + + err = abx500_set_register_interruptible(dev, variant->bank, + AB5500_READREQ, + AB5500_READREQ_REQ); + if (err < 0) + return err; + + timeout = jiffies + HZ; + while (time_before(jiffies, timeout)) { + u8 value; + + err = abx500_get_register_interruptible(dev, variant->bank, + AB5500_READREQ, &value); + if (err < 0) + return err; + + if (!(value & AB5500_READREQ_REQ)) + return 0; + + msleep(1); + } + + return -EIO; +} + +static void +ab5500_rtc_time_to_regs(struct device *dev, unsigned long secs, u8 *regs) +{ + unsigned long mins = secs / 60; + u64 fat_time; + + secs %= 60; + + fat_time = secs * AB5500_RTC_CLOCK_RATE; + fat_time |= (u64)mins << 21; + + regs[0] = (fat_time) & 0xFF; + regs[1] = (fat_time >> 8) & 0xFF; + regs[2] = (fat_time >> 16) & 0xFF; + regs[3] = (fat_time >> 24) & 0xFF; + regs[4] = (fat_time >> 32) & 0xFF; + regs[5] = (fat_time >> 40) & 0xFF; +} + +static unsigned long +ab5500_rtc_regs_to_time(struct device *dev, u8 *regs) +{ + u64 fat_time = ((u64)regs[5] << 40) | ((u64)regs[4] << 32) | + (regs[3] << 24) | (regs[2] << 16) | + (regs[1] << 8) | regs[0]; + unsigned long secs = (fat_time & 0x1fffff) / AB5500_RTC_CLOCK_RATE; + unsigned long mins = fat_time >> 21; + + return mins * 60 + secs; +} + +static void +ab5500_rtc_alarm_to_regs(struct device *dev, unsigned long secs, u8 *regs) +{ + unsigned long mins = secs / 60; + +#ifdef CONFIG_ANDROID + /* + * Needed because Android believes all hw have a wake-up resolution in + * seconds. + */ + mins++; +#endif + + regs[0] = mins & 0xFF; + regs[1] = (mins >> 8) & 0xFF; + regs[2] = (mins >> 16) & 0xFF; +} + +static unsigned long +ab5500_rtc_regs_to_alarm(struct device *dev, u8 *regs) +{ + unsigned long mins = (regs[2] << 16) | (regs[1] << 8) | regs[0]; + unsigned long secs = mins * 60; + + return secs; +} + +static const struct ab_rtc ab5500_rtc = { + .irqname = "RTC_Alarm", + .bank = AB5500_BANK_RTC, + .rtc = AB5500_RTC, + .rtc_alarmon = AB5500_RTC_ALARM, + .ti0 = AB5500_TI0, + .nr_ti = 6, + .al0 = AB5500_AL0, + .nr_al = 3, + .epoch = 2000, + .time_to_regs = ab5500_rtc_time_to_regs, + .regs_to_time = ab5500_rtc_regs_to_time, + .alarm_to_regs = ab5500_rtc_alarm_to_regs, + .regs_to_alarm = ab5500_rtc_regs_to_alarm, + .request_read = ab5500_rtc_request_read, +}; + +static int ab_rtc_request_read(struct device *dev) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + + if (!variant->request_read) + return 0; + + return variant->request_read(dev); +} + +static int ab_rtc_request_write(struct device *dev) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + + if (!variant->request_write) + return 0; + + return variant->request_write(dev); +} + +static bool ab_rtc_valid_time(struct device *dev, struct rtc_time *time) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + + if (!variant->epoch) + return true; + + return time->tm_year >= variant->epoch - 1900; +} + +static int +ab_rtc_tm_to_time(struct device *dev, struct rtc_time *tm, unsigned long *secs) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + + rtc_tm_to_time(tm, secs); + + if (variant->epoch) + *secs -= ab_rtc_get_elapsed_seconds(variant->epoch); + + return 0; +} + +static int +ab_rtc_time_to_tm(struct device *dev, unsigned long secs, struct rtc_time *tm) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + + if (variant->epoch) + secs += ab_rtc_get_elapsed_seconds(variant->epoch); + + rtc_time_to_tm(secs, tm); + + return 0; +} + +static int ab_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + unsigned char buf[variant->nr_ti]; + unsigned long secs; + int err; + + err = ab_rtc_request_read(dev); + if (err) + return err; + + err = abx500_get_register_page_interruptible(dev, variant->bank, + variant->ti0, + buf, variant->nr_ti); + if (err) + return err; + + secs = variant->regs_to_time(dev, buf); + ab_rtc_time_to_tm(dev, secs, tm); + + return rtc_valid_tm(tm); +} + +static int ab_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + unsigned char buf[variant->nr_ti]; + unsigned long secs; + u8 reg = variant->ti0; + int err; + int i; + + if (!ab_rtc_valid_time(dev, tm)) + return -EINVAL; + + ab_rtc_tm_to_time(dev, tm, &secs); + variant->time_to_regs(dev, secs, buf); + + for (i = 0; i < variant->nr_ti; i++, reg++) { + err = abx500_set_register_interruptible(dev, variant->bank, + reg, buf[i]); + if (err) + return err; + } + + return ab_rtc_request_write(dev); +} + +static int ab_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + unsigned long secs; + u8 buf[variant->nr_al]; + u8 rtcval; + int err; + + err = abx500_get_register_interruptible(dev, variant->bank, + variant->rtc, &rtcval); + if (err) + return err; + + alarm->enabled = !!(rtcval & variant->rtc_alarmon); + alarm->pending = 0; + + err = abx500_get_register_page_interruptible(dev, variant->bank, + variant->al0, buf, + variant->nr_al); + if (err) + return err; + + secs = variant->regs_to_alarm(dev, buf); + ab_rtc_time_to_tm(dev, secs, &alarm->time); + + return rtc_valid_tm(&alarm->time); +} + +static int ab_rtc_alarm_enable(struct device *dev, unsigned int enabled) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + u8 mask = variant->rtc_alarmon; + u8 value = enabled ? mask : 0; + + return abx500_mask_and_set_register_interruptible(dev, variant->bank, + variant->rtc, mask, + value); +} + +static int ab_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + const struct ab_rtc *variant = to_ab_rtc(dev); + unsigned char buf[variant->nr_al]; + unsigned long secs; + u8 reg = variant->al0; + int err; + int i; + + if (!ab_rtc_valid_time(dev, &alarm->time)) + return -EINVAL; + + ab_rtc_tm_to_time(dev, &alarm->time, &secs); + variant->alarm_to_regs(dev, secs, buf); + + /* + * Disable alarm first. Otherwise the RTC may not detect an alarm + * reprogrammed for the same time without disabling the alarm in + * between the programmings. + */ + err = ab_rtc_alarm_enable(dev, false); + if (err) + return err; + + for (i = 0; i < variant->nr_al; i++, reg++) { + err = abx500_set_register_interruptible(dev, variant->bank, + reg, buf[i]); + if (err) + return err; + } + + return ab_rtc_alarm_enable(dev, true); +} + +static const struct rtc_class_ops ab_rtc_ops = { + .read_time = ab_rtc_read_time, + .set_time = ab_rtc_set_time, + .read_alarm = ab_rtc_read_alarm, + .set_alarm = ab_rtc_set_alarm, + .alarm_irq_enable = ab_rtc_alarm_enable, +}; + +static irqreturn_t ab_rtc_irq(int irq, void *dev_id) +{ + unsigned long events = RTC_IRQF | RTC_AF; + struct rtc_device *rtc = dev_id; + + rtc_update_irq(rtc, 1, events); + + return IRQ_HANDLED; +} + +static int __devinit ab_rtc_probe(struct platform_device *pdev) +{ + const struct ab_rtc *variant = to_ab_rtc(&pdev->dev); + int err; + struct rtc_device *rtc; + int irq = -ENXIO; + + if (variant->irqname) { + irq = platform_get_irq_byname(pdev, variant->irqname); + if (irq < 0) + return irq; + } + + if (variant->startup) { + err = variant->startup(&pdev->dev); + if (err) + return err; + } + + rtc = rtc_device_register("ab8500-rtc", &pdev->dev, &ab_rtc_ops, + THIS_MODULE); + if (IS_ERR(rtc)) { + dev_err(&pdev->dev, "Registration failed\n"); + err = PTR_ERR(rtc); + return err; + } + + if (irq >= 0) { + err = request_any_context_irq(irq, ab_rtc_irq, + IRQF_NO_SUSPEND, + pdev->id_entry->name, + rtc); + if (err < 0) { + dev_err(&pdev->dev, "could not get irq: %d\n", err); + goto out_unregister; + } + } + + platform_set_drvdata(pdev, rtc); + + return 0; + +out_unregister: + rtc_device_unregister(rtc); + return err; +} + +static int __devexit ab_rtc_remove(struct platform_device *pdev) +{ + const struct ab_rtc *variant = to_ab_rtc(&pdev->dev); + struct rtc_device *rtc = platform_get_drvdata(pdev); + int irq = platform_get_irq_byname(pdev, variant->irqname); + + if (irq >= 0) + free_irq(irq, rtc); + rtc_device_unregister(rtc); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_device_id ab_rtc_id_table[] = { + { "ab5500-rtc", (kernel_ulong_t)&ab5500_rtc, }, + { }, +}; +MODULE_DEVICE_TABLE(platform, ab_rtc_id_table); + +static struct platform_driver ab_rtc_driver = { + .driver.name = "ab-rtc", + .driver.owner = THIS_MODULE, + .id_table = ab_rtc_id_table, + .probe = ab_rtc_probe, + .remove = __devexit_p(ab_rtc_remove), +}; + +static int __init ab_rtc_init(void) +{ + return platform_driver_register(&ab_rtc_driver); +} +module_init(ab_rtc_init); + +static void __exit ab_rtc_exit(void) +{ + platform_driver_unregister(&ab_rtc_driver); +} +module_exit(ab_rtc_exit); + +MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>"); +MODULE_DESCRIPTION("AB5500 RTC Driver"); +MODULE_LICENSE("GPL v2"); |