diff options
Diffstat (limited to 'drivers/rtc/rtc-tx4939.c')
| -rw-r--r-- | drivers/rtc/rtc-tx4939.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-tx4939.c b/drivers/rtc/rtc-tx4939.c new file mode 100644 index 000000000..715b82981 --- /dev/null +++ b/drivers/rtc/rtc-tx4939.c @@ -0,0 +1,304 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * TX4939 internal RTC driver + * Based on RBTX49xx patch from CELF patch archive. + * + * (C) Copyright TOSHIBA CORPORATION 2005-2007 + */ +#include <linux/rtc.h> +#include <linux/platform_device.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/gfp.h> + +#define TX4939_RTCCTL_ALME 0x00000080 +#define TX4939_RTCCTL_ALMD 0x00000040 +#define TX4939_RTCCTL_BUSY 0x00000020 + +#define TX4939_RTCCTL_COMMAND 0x00000007 +#define TX4939_RTCCTL_COMMAND_NOP 0x00000000 +#define TX4939_RTCCTL_COMMAND_GETTIME 0x00000001 +#define TX4939_RTCCTL_COMMAND_SETTIME 0x00000002 +#define TX4939_RTCCTL_COMMAND_GETALARM 0x00000003 +#define TX4939_RTCCTL_COMMAND_SETALARM 0x00000004 + +#define TX4939_RTCTBC_PM 0x00000080 +#define TX4939_RTCTBC_COMP 0x0000007f + +#define TX4939_RTC_REG_RAMSIZE 0x00000100 +#define TX4939_RTC_REG_RWBSIZE 0x00000006 + +struct tx4939_rtc_reg { + __u32 ctl; + __u32 adr; + __u32 dat; + __u32 tbc; +}; + +struct tx4939rtc_plat_data { + struct rtc_device *rtc; + struct tx4939_rtc_reg __iomem *rtcreg; + spinlock_t lock; +}; + +static int tx4939_rtc_cmd(struct tx4939_rtc_reg __iomem *rtcreg, int cmd) +{ + int i = 0; + + __raw_writel(cmd, &rtcreg->ctl); + /* This might take 30us (next 32.768KHz clock) */ + while (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_BUSY) { + /* timeout on approx. 100us (@ GBUS200MHz) */ + if (i++ > 200 * 100) + return -EBUSY; + cpu_relax(); + } + return 0; +} + +static int tx4939_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev); + struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg; + unsigned long secs = rtc_tm_to_time64(tm); + int i, ret; + unsigned char buf[6]; + + buf[0] = 0; + buf[1] = 0; + buf[2] = secs; + buf[3] = secs >> 8; + buf[4] = secs >> 16; + buf[5] = secs >> 24; + spin_lock_irq(&pdata->lock); + __raw_writel(0, &rtcreg->adr); + for (i = 0; i < 6; i++) + __raw_writel(buf[i], &rtcreg->dat); + ret = tx4939_rtc_cmd(rtcreg, + TX4939_RTCCTL_COMMAND_SETTIME | + (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME)); + spin_unlock_irq(&pdata->lock); + return ret; +} + +static int tx4939_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev); + struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg; + int i, ret; + unsigned long sec; + unsigned char buf[6]; + + spin_lock_irq(&pdata->lock); + ret = tx4939_rtc_cmd(rtcreg, + TX4939_RTCCTL_COMMAND_GETTIME | + (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME)); + if (ret) { + spin_unlock_irq(&pdata->lock); + return ret; + } + __raw_writel(2, &rtcreg->adr); + for (i = 2; i < 6; i++) + buf[i] = __raw_readl(&rtcreg->dat); + spin_unlock_irq(&pdata->lock); + sec = ((unsigned long)buf[5] << 24) | (buf[4] << 16) | + (buf[3] << 8) | buf[2]; + rtc_time64_to_tm(sec, tm); + return 0; +} + +static int tx4939_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev); + struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg; + int i, ret; + unsigned long sec; + unsigned char buf[6]; + + sec = rtc_tm_to_time64(&alrm->time); + buf[0] = 0; + buf[1] = 0; + buf[2] = sec; + buf[3] = sec >> 8; + buf[4] = sec >> 16; + buf[5] = sec >> 24; + spin_lock_irq(&pdata->lock); + __raw_writel(0, &rtcreg->adr); + for (i = 0; i < 6; i++) + __raw_writel(buf[i], &rtcreg->dat); + ret = tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_SETALARM | + (alrm->enabled ? TX4939_RTCCTL_ALME : 0)); + spin_unlock_irq(&pdata->lock); + return ret; +} + +static int tx4939_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev); + struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg; + int i, ret; + unsigned long sec; + unsigned char buf[6]; + u32 ctl; + + spin_lock_irq(&pdata->lock); + ret = tx4939_rtc_cmd(rtcreg, + TX4939_RTCCTL_COMMAND_GETALARM | + (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME)); + if (ret) { + spin_unlock_irq(&pdata->lock); + return ret; + } + __raw_writel(2, &rtcreg->adr); + for (i = 2; i < 6; i++) + buf[i] = __raw_readl(&rtcreg->dat); + ctl = __raw_readl(&rtcreg->ctl); + alrm->enabled = (ctl & TX4939_RTCCTL_ALME) ? 1 : 0; + alrm->pending = (ctl & TX4939_RTCCTL_ALMD) ? 1 : 0; + spin_unlock_irq(&pdata->lock); + sec = ((unsigned long)buf[5] << 24) | (buf[4] << 16) | + (buf[3] << 8) | buf[2]; + rtc_time64_to_tm(sec, &alrm->time); + return rtc_valid_tm(&alrm->time); +} + +static int tx4939_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev); + + spin_lock_irq(&pdata->lock); + tx4939_rtc_cmd(pdata->rtcreg, + TX4939_RTCCTL_COMMAND_NOP | + (enabled ? TX4939_RTCCTL_ALME : 0)); + spin_unlock_irq(&pdata->lock); + return 0; +} + +static irqreturn_t tx4939_rtc_interrupt(int irq, void *dev_id) +{ + struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev_id); + struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg; + unsigned long events = RTC_IRQF; + + spin_lock(&pdata->lock); + if (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALMD) { + events |= RTC_AF; + tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_NOP); + } + spin_unlock(&pdata->lock); + rtc_update_irq(pdata->rtc, 1, events); + + return IRQ_HANDLED; +} + +static const struct rtc_class_ops tx4939_rtc_ops = { + .read_time = tx4939_rtc_read_time, + .read_alarm = tx4939_rtc_read_alarm, + .set_alarm = tx4939_rtc_set_alarm, + .set_time = tx4939_rtc_set_time, + .alarm_irq_enable = tx4939_rtc_alarm_irq_enable, +}; + +static int tx4939_nvram_read(void *priv, unsigned int pos, void *val, + size_t bytes) +{ + struct tx4939rtc_plat_data *pdata = priv; + struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg; + u8 *buf = val; + + spin_lock_irq(&pdata->lock); + for (; bytes; bytes--) { + __raw_writel(pos++, &rtcreg->adr); + *buf++ = __raw_readl(&rtcreg->dat); + } + spin_unlock_irq(&pdata->lock); + return 0; +} + +static int tx4939_nvram_write(void *priv, unsigned int pos, void *val, + size_t bytes) +{ + struct tx4939rtc_plat_data *pdata = priv; + struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg; + u8 *buf = val; + + spin_lock_irq(&pdata->lock); + for (; bytes; bytes--) { + __raw_writel(pos++, &rtcreg->adr); + __raw_writel(*buf++, &rtcreg->dat); + } + spin_unlock_irq(&pdata->lock); + return 0; +} + +static int __init tx4939_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtc; + struct tx4939rtc_plat_data *pdata; + int irq, ret; + struct nvmem_config nvmem_cfg = { + .name = "tx4939_nvram", + .size = TX4939_RTC_REG_RAMSIZE, + .reg_read = tx4939_nvram_read, + .reg_write = tx4939_nvram_write, + }; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return -ENODEV; + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + platform_set_drvdata(pdev, pdata); + + pdata->rtcreg = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(pdata->rtcreg)) + return PTR_ERR(pdata->rtcreg); + + spin_lock_init(&pdata->lock); + tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP); + if (devm_request_irq(&pdev->dev, irq, tx4939_rtc_interrupt, + 0, pdev->name, &pdev->dev) < 0) + return -EBUSY; + rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &tx4939_rtc_ops; + rtc->nvram_old_abi = true; + rtc->range_max = U32_MAX; + + pdata->rtc = rtc; + + nvmem_cfg.priv = pdata; + ret = rtc_nvmem_register(rtc, &nvmem_cfg); + if (ret) + return ret; + + return rtc_register_device(rtc); +} + +static int __exit tx4939_rtc_remove(struct platform_device *pdev) +{ + struct tx4939rtc_plat_data *pdata = platform_get_drvdata(pdev); + + spin_lock_irq(&pdata->lock); + tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP); + spin_unlock_irq(&pdata->lock); + return 0; +} + +static struct platform_driver tx4939_rtc_driver = { + .remove = __exit_p(tx4939_rtc_remove), + .driver = { + .name = "tx4939rtc", + }, +}; + +module_platform_driver_probe(tx4939_rtc_driver, tx4939_rtc_probe); + +MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>"); +MODULE_DESCRIPTION("TX4939 internal RTC driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:tx4939rtc"); |