From b3ed3864912e8809e228ddea259e8e0fa1deadf5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Sat, 2 Jul 2016 17:28:08 +0200 Subject: rtc: s35390a: fix reading out alarm MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit f87e904ddd8f0ef120e46045b0addeb1cc88354e upstream. There are several issues fixed in this patch: - When alarm isn't enabled, set .enabled to zero instead of returning -EINVAL. - Ignore how IRQ1 is configured when determining if IRQ2 is on. - The three alarm registers have an enable flag which must be evaluated. - The chip always triggers when the seconds register gets 0. Note that the rtc framework however doesn't handle the result correctly because it doesn't check wday being initialized and so interprets an alarm being set for 10:00 AM in three days as 10:00 AM tomorrow (or today if that's not over yet). Signed-off-by: Uwe Kleine-König Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-s35390a.c | 40 +++++++++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 9 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c index f40afdd0e5f5..6507a01cf9ad 100644 --- a/drivers/rtc/rtc-s35390a.c +++ b/drivers/rtc/rtc-s35390a.c @@ -242,6 +242,8 @@ static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm) if (alm->time.tm_wday != -1) buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80; + else + buf[S35390A_ALRM_BYTE_WDAY] = 0; buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a, alm->time.tm_hour) | 0x80; @@ -269,23 +271,43 @@ static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm) if (err < 0) return err; - if (bitrev8(sts) != S35390A_INT2_MODE_ALARM) - return -EINVAL; + if ((bitrev8(sts) & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) { + /* + * When the alarm isn't enabled, the register to configure + * the alarm time isn't accessible. + */ + alm->enabled = 0; + return 0; + } else { + alm->enabled = 1; + } err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf)); if (err < 0) return err; /* This chip returns the bits of each byte in reverse order */ - for (i = 0; i < 3; ++i) { + for (i = 0; i < 3; ++i) buf[i] = bitrev8(buf[i]); - buf[i] &= ~0x80; - } - alm->time.tm_wday = bcd2bin(buf[S35390A_ALRM_BYTE_WDAY]); - alm->time.tm_hour = s35390a_reg2hr(s35390a, - buf[S35390A_ALRM_BYTE_HOURS]); - alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS]); + /* + * B0 of the three matching registers is an enable flag. Iff it is set + * the configured value is used for matching. + */ + if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80) + alm->time.tm_wday = + bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80); + + if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80) + alm->time.tm_hour = + s35390a_reg2hr(s35390a, + buf[S35390A_ALRM_BYTE_HOURS] & ~0x80); + + if (buf[S35390A_ALRM_BYTE_MINS] & 0x80) + alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80); + + /* alarm triggers always at s=0 */ + alm->time.tm_sec = 0; dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n", __func__, alm->time.tm_min, alm->time.tm_hour, -- cgit v1.2.3 From fdd4bc9313e59a1757cfc8ac5836cff55ec03eeb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Mon, 3 Apr 2017 23:32:38 +0200 Subject: rtc: s35390a: make sure all members in the output are set MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The rtc core calls the .read_alarm with all fields initialized to 0. As the s35390a driver doesn't touch some fields the returned date is interpreted as a date in January 1900. So make sure all fields are set to -1; some of them are then overwritten with the right data depending on the hardware state. In mainline this is done by commit d68778b80dd7 ("rtc: initialize output parameter for read alarm to "uninitialized"") in the core. This is considered to dangerous for stable as it might have side effects for other rtc drivers that might for example rely on alarm->time.tm_sec being initialized to 0. Signed-off-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-s35390a.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c index 6507a01cf9ad..47b88bbe4ce7 100644 --- a/drivers/rtc/rtc-s35390a.c +++ b/drivers/rtc/rtc-s35390a.c @@ -267,6 +267,20 @@ static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm) char buf[3], sts; int i, err; + /* + * initialize all members to -1 to signal the core that they are not + * defined by the hardware. + */ + alm->time.tm_sec = -1; + alm->time.tm_min = -1; + alm->time.tm_hour = -1; + alm->time.tm_mday = -1; + alm->time.tm_mon = -1; + alm->time.tm_year = -1; + alm->time.tm_wday = -1; + alm->time.tm_yday = -1; + alm->time.tm_isdst = -1; + err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts)); if (err < 0) return err; -- cgit v1.2.3 From a55ae9d1937b0bf4004e5416cfa15750cd6d2b22 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Sat, 2 Jul 2016 17:28:09 +0200 Subject: rtc: s35390a: implement reset routine as suggested by the reference MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 8e6583f1b5d1f5f129b873f1428b7e414263d847 upstream. There were two deviations from the reference manual: you have to wait half a second when POC is active and you might have to repeat initialization when POC or BLD are still set after the sequence. Note however that as POC and BLD are cleared by read the driver might not be able to detect that a reset is necessary. I don't have a good idea how to fix this. Additionally report the value read from STATUS1 to the caller. This prepares the next patch. Signed-off-by: Uwe Kleine-König Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-s35390a.c | 65 +++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 55 insertions(+), 10 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c index 47b88bbe4ce7..c7c1fce69635 100644 --- a/drivers/rtc/rtc-s35390a.c +++ b/drivers/rtc/rtc-s35390a.c @@ -15,6 +15,7 @@ #include #include #include +#include #define S35390A_CMD_STATUS1 0 #define S35390A_CMD_STATUS2 1 @@ -94,19 +95,63 @@ static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len) return 0; } -static int s35390a_reset(struct s35390a *s35390a) +/* + * Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset. + * To keep the information if an irq is pending, pass the value read from + * STATUS1 to the caller. + */ +static int s35390a_reset(struct s35390a *s35390a, char *status1) { - char buf[1]; + char buf; + int ret; + unsigned initcount = 0; - if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)) < 0) - return -EIO; + ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1); + if (ret < 0) + return ret; - if (!(buf[0] & (S35390A_FLAG_POC | S35390A_FLAG_BLD))) + if (*status1 & S35390A_FLAG_POC) + /* + * Do not communicate for 0.5 seconds since the power-on + * detection circuit is in operation. + */ + msleep(500); + else if (!(*status1 & S35390A_FLAG_BLD)) + /* + * If both POC and BLD are unset everything is fine. + */ return 0; - buf[0] |= (S35390A_FLAG_RESET | S35390A_FLAG_24H); - buf[0] &= 0xf0; - return s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)); + /* + * At least one of POC and BLD are set, so reinitialise chip. Keeping + * this information in the hardware to know later that the time isn't + * valid is unfortunately not possible because POC and BLD are cleared + * on read. So the reset is best done now. + * + * The 24H bit is kept over reset, so set it already here. + */ +initialize: + *status1 = S35390A_FLAG_24H; + buf = S35390A_FLAG_RESET | S35390A_FLAG_24H; + ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1); + + if (ret < 0) + return ret; + + ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1); + if (ret < 0) + return ret; + + if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) { + /* Try up to five times to reset the chip */ + if (initcount < 5) { + ++initcount; + goto initialize; + } else + return -EIO; + } + + return 1; } static int s35390a_disable_test_mode(struct s35390a *s35390a) @@ -367,7 +412,7 @@ static int s35390a_probe(struct i2c_client *client, unsigned int i; struct s35390a *s35390a; struct rtc_time tm; - char buf[1]; + char buf[1], status1; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { err = -ENODEV; @@ -396,7 +441,7 @@ static int s35390a_probe(struct i2c_client *client, } } - err = s35390a_reset(s35390a); + err = s35390a_reset(s35390a, &status1); if (err < 0) { dev_err(&client->dev, "error resetting chip\n"); goto exit_dummy; -- cgit v1.2.3 From 3a1246b46df5210164ee43d4c5c560d0dc9ed2ce Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Sat, 2 Jul 2016 17:28:10 +0200 Subject: rtc: s35390a: improve irq handling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 3bd32722c827d00eafe8e6d5b83e9f3148ea7c7e upstream. On some QNAP NAS devices the rtc can wake the machine. Several people noticed that once the machine was woken this way it fails to shut down. That's because the driver fails to acknowledge the interrupt and so it keeps active and restarts the machine immediatly after shutdown. See https://bugs.debian.org/794266 for a bug report. Doing this correctly requires to interpret the INT2 flag of the first read of the STATUS1 register because this bit is cleared by read. Note this is not maximally robust though because a pending irq isn't detected when the STATUS1 register was already read (and so INT2 is not set) but the irq was not disabled. But that is a hardware imposed problem that cannot easily be fixed by software. Signed-off-by: Uwe Kleine-König Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-s35390a.c | 48 ++++++++++++++++++++++++++++++----------------- 1 file changed, 31 insertions(+), 17 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c index c7c1fce69635..00662dd28d66 100644 --- a/drivers/rtc/rtc-s35390a.c +++ b/drivers/rtc/rtc-s35390a.c @@ -35,10 +35,14 @@ #define S35390A_ALRM_BYTE_HOURS 1 #define S35390A_ALRM_BYTE_MINS 2 +/* flags for STATUS1 */ #define S35390A_FLAG_POC 0x01 #define S35390A_FLAG_BLD 0x02 +#define S35390A_FLAG_INT2 0x04 #define S35390A_FLAG_24H 0x40 #define S35390A_FLAG_RESET 0x80 + +/* flag for STATUS2 */ #define S35390A_FLAG_TEST 0x01 #define S35390A_INT2_MODE_MASK 0xF0 @@ -408,11 +412,11 @@ static struct i2c_driver s35390a_driver; static int s35390a_probe(struct i2c_client *client, const struct i2c_device_id *id) { - int err; + int err, err_reset; unsigned int i; struct s35390a *s35390a; struct rtc_time tm; - char buf[1], status1; + char buf, status1; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { err = -ENODEV; @@ -441,29 +445,35 @@ static int s35390a_probe(struct i2c_client *client, } } - err = s35390a_reset(s35390a, &status1); - if (err < 0) { + err_reset = s35390a_reset(s35390a, &status1); + if (err_reset < 0) { + err = err_reset; dev_err(&client->dev, "error resetting chip\n"); goto exit_dummy; } - err = s35390a_disable_test_mode(s35390a); - if (err < 0) { - dev_err(&client->dev, "error disabling test mode\n"); - goto exit_dummy; - } - - err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)); - if (err < 0) { - dev_err(&client->dev, "error checking 12/24 hour mode\n"); - goto exit_dummy; - } - if (buf[0] & S35390A_FLAG_24H) + if (status1 & S35390A_FLAG_24H) s35390a->twentyfourhour = 1; else s35390a->twentyfourhour = 0; - if (s35390a_get_datetime(client, &tm) < 0) + if (status1 & S35390A_FLAG_INT2) { + /* disable alarm (and maybe test mode) */ + buf = 0; + err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1); + if (err < 0) { + dev_err(&client->dev, "error disabling alarm"); + goto exit_dummy; + } + } else { + err = s35390a_disable_test_mode(s35390a); + if (err < 0) { + dev_err(&client->dev, "error disabling test mode\n"); + goto exit_dummy; + } + } + + if (err_reset > 0 || s35390a_get_datetime(client, &tm) < 0) dev_warn(&client->dev, "clock needs to be set\n"); device_set_wakeup_capable(&client->dev, 1); @@ -476,6 +486,10 @@ static int s35390a_probe(struct i2c_client *client, err = PTR_ERR(s35390a->rtc); goto exit_dummy; } + + if (status1 & S35390A_FLAG_INT2) + rtc_update_irq(s35390a->rtc, 1, RTC_AF); + return 0; exit_dummy: -- cgit v1.2.3 From ba02781392fa1b934e41785a5301ca21ad44708b Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Thu, 12 Jan 2017 17:07:43 +0100 Subject: rtc: tegra: Implement clock handling commit 5fa4086987506b2ab8c92f8f99f2295db9918856 upstream. Accessing the registers of the RTC block on Tegra requires the module clock to be enabled. This only works because the RTC module clock will be enabled by default during early boot. However, because the clock is unused, the CCF will disable it at late_init time. This causes the RTC to become unusable afterwards. This can easily be reproduced by trying to use the RTC: $ hwclock --rtc /dev/rtc1 This will hang the system. I ran into this by following up on a report by Martin Michlmayr that reboot wasn't working on Tegra210 systems. It turns out that the rtc-tegra driver's ->shutdown() implementation will hang the CPU, because of the disabled clock, before the system can be rebooted. What confused me for a while is that the same driver is used on prior Tegra generations where the hang can not be observed. However, as Peter De Schrijver pointed out, this is because on 32-bit Tegra chips the RTC clock is enabled by the tegra20_timer.c clocksource driver, which uses the RTC to provide a persistent clock. This code is never enabled on 64-bit Tegra because the persistent clock infrastructure does not exist on 64-bit ARM. The proper fix for this is to add proper clock handling to the RTC driver in order to ensure that the clock is enabled when the driver requires it. All device trees contain the clock already, therefore no additional changes are required. Reported-by: Martin Michlmayr Acked-By Peter De Schrijver Signed-off-by: Thierry Reding Signed-off-by: Alexandre Belloni [bwh: Backported to 4.9: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-tegra.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-tegra.c b/drivers/rtc/rtc-tegra.c index 60232bd366ef..71216aa68905 100644 --- a/drivers/rtc/rtc-tegra.c +++ b/drivers/rtc/rtc-tegra.c @@ -18,6 +18,7 @@ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include +#include #include #include #include @@ -59,6 +60,7 @@ struct tegra_rtc_info { struct platform_device *pdev; struct rtc_device *rtc_dev; void __iomem *rtc_base; /* NULL if not initialized. */ + struct clk *clk; int tegra_rtc_irq; /* alarm and periodic irq */ spinlock_t tegra_rtc_lock; }; @@ -332,6 +334,14 @@ static int __init tegra_rtc_probe(struct platform_device *pdev) if (info->tegra_rtc_irq <= 0) return -EBUSY; + info->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(info->clk)) + return PTR_ERR(info->clk); + + ret = clk_prepare_enable(info->clk); + if (ret < 0) + return ret; + /* set context info. */ info->pdev = pdev; spin_lock_init(&info->tegra_rtc_lock); @@ -352,7 +362,7 @@ static int __init tegra_rtc_probe(struct platform_device *pdev) ret = PTR_ERR(info->rtc_dev); dev_err(&pdev->dev, "Unable to register device (err=%d).\n", ret); - return ret; + goto disable_clk; } ret = devm_request_irq(&pdev->dev, info->tegra_rtc_irq, @@ -362,11 +372,24 @@ static int __init tegra_rtc_probe(struct platform_device *pdev) dev_err(&pdev->dev, "Unable to request interrupt for device (err=%d).\n", ret); - return ret; + goto disable_clk; } dev_notice(&pdev->dev, "Tegra internal Real Time Clock\n"); + return 0; + +disable_clk: + clk_disable_unprepare(info->clk); + return ret; +} + +static int tegra_rtc_remove(struct platform_device *pdev) +{ + struct tegra_rtc_info *info = platform_get_drvdata(pdev); + + clk_disable_unprepare(info->clk); + return 0; } @@ -419,6 +442,7 @@ static void tegra_rtc_shutdown(struct platform_device *pdev) MODULE_ALIAS("platform:tegra_rtc"); static struct platform_driver tegra_rtc_driver = { + .remove = tegra_rtc_remove, .shutdown = tegra_rtc_shutdown, .driver = { .name = "tegra_rtc", -- cgit v1.2.3