| Message ID | 20170827003328.28370-3-afaerber@suse.de |
|---|---|
| State | Superseded |
| Headers | show |
| Series | arm64: Realtek RTD1295 RTC | expand |
n Sun, Aug 27, 2017 at 02:33:27AM +0200, Andreas Färber wrote: > Based on QNAP's arch/arm/mach-rtk119x/driver/rtk_rtc_drv.c code and > mach-rtk119x/driver/dc2vo/fpga/include/mis_reg.h register definitions. > > The base year 2014 was observed on all of Zidoo X9S, ProBox2 Ava and > Beelink Lake I. > > Signed-off-by: Andreas Färber <afaerber@suse.de> > --- > v1 -> v2: > * Dropped open/release in favor of probe/remove (Alexandre) > * read_time: Reordered register accesses (Alexandre) > * read_time/set_time: Refactored day calculations to avoid time64_t (Alexandre) > * read_time: Retry if seconds change (Alexandre) > * probe: Added missing RTCACR initialization code > * set_time: Fixed year check (off by 1900) > * set_time: Fixed new seconds (off by factor two) > * Cleaned up debug output (Andrew) > * Added spinlocks around register accesses > * Added masks for register fields > > drivers/rtc/Kconfig | 8 ++ > drivers/rtc/Makefile | 1 + > drivers/rtc/rtc-rtd119x.c | 254 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 263 insertions(+) > create mode 100644 drivers/rtc/rtc-rtd119x.c > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index 22efa21b1d81..d5a46f311ecb 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -1765,6 +1765,14 @@ config RTC_DRV_CPCAP > Say y here for CPCAP rtc found on some Motorola phones > and tablets such as Droid 4. > > +config RTC_DRV_RTD119X > + bool "Realtek RTD129x RTC" > + depends on ARCH_REALTEK || COMPILE_TEST > + default ARCH_REALTEK > + help > + If you say yes here, you get support for the RTD1295 SoC > + Real Time Clock. > + > comment "HID Sensor RTC drivers" > > config RTC_DRV_HID_SENSOR_TIME > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile > index acd366b41c85..55a0a5ca45b0 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -131,6 +131,7 @@ obj-$(CONFIG_RTC_DRV_RP5C01) += rtc-rp5c01.o > obj-$(CONFIG_RTC_DRV_RS5C313) += rtc-rs5c313.o > obj-$(CONFIG_RTC_DRV_RS5C348) += rtc-rs5c348.o > obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o > +obj-$(CONFIG_RTC_DRV_RTD119X) += rtc-rtd119x.o > obj-$(CONFIG_RTC_DRV_RV3029C2) += rtc-rv3029c2.o > obj-$(CONFIG_RTC_DRV_RV8803) += rtc-rv8803.o > obj-$(CONFIG_RTC_DRV_RX4581) += rtc-rx4581.o > diff --git a/drivers/rtc/rtc-rtd119x.c b/drivers/rtc/rtc-rtd119x.c > new file mode 100644 > index 000000000000..27fa68a5af30 > --- /dev/null > +++ b/drivers/rtc/rtc-rtd119x.c > @@ -0,0 +1,254 @@ > +/* > + * Realtek RTD129x RTC > + * > + * Copyright (c) 2017 Andreas Färber > + * > + * SPDX-License-Identifier: GPL-2.0+ > + */ > + > +#include <linux/clk.h> > +#include <linux/io.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/platform_device.h> > +#include <linux/rtc.h> > +#include <linux/spinlock.h> > + > +#define RTD_RTCSEC 0x00 > +#define RTD_RTCMIN 0x04 > +#define RTD_RTCHR 0x08 > +#define RTD_RTCDATE1 0x0c > +#define RTD_RTCDATE2 0x10 > +#define RTD_RTCACR 0x28 > +#define RTD_RTCEN 0x2c > +#define RTD_RTCCR 0x30 > + > +#define RTD_RTCSEC_RTCSEC_MASK 0x7f > + > +#define RTD_RTCMIN_RTCMIN_MASK 0x3f > + > +#define RTD_RTCHR_RTCHR_MASK 0x1f > + > +#define RTD_RTCDATE1_RTCDATE1_MASK 0xff > + > +#define RTD_RTCDATE2_RTCDATE2_MASK 0x7f > + > +#define RTD_RTCACR_RTCPWR BIT(7) > + > +#define RTD_RTCEN_RTCEN_MASK 0xff > + > +#define RTD_RTCCR_RTCRST BIT(6) > + > +struct rtd119x_rtc { > + void __iomem *base; > + struct clk *clk; > + struct rtc_device *rtcdev; > + unsigned base_year; > + spinlock_t lock; Where is this lock initialised? I would expect a call to spin_lock_init() somewhere. I also wonder what this lock is protecting, which rtc->ops_lock does not protect? Andrew
Am 27.08.2017 um 04:05 schrieb Andrew Lunn: > n Sun, Aug 27, 2017 at 02:33:27AM +0200, Andreas Färber wrote: >> +struct rtd119x_rtc { >> + void __iomem *base; >> + struct clk *clk; >> + struct rtc_device *rtcdev; >> + unsigned base_year; >> + spinlock_t lock; > > Where is this lock initialised? I would expect a call to > spin_lock_init() somewhere. Hm, the spinlock in my irq mux series doesn't have that call either; my reset driver did have it. The zero initialization appears to work OK, but you're probably right that it should be there. > I also wonder what this lock is protecting, which rtc->ops_lock does > not protect? By that same argument we could ask why so many drivers (and mine, too) are calling rtc_valid_tm() when __rtc_read_time() calls it again... The downstream code is locking inside individual functions such as check_acr or set_enabled; I adopted it for whole operations only, but you're right that so far it matches the RTC class ops granularity, so I can drop it again. The latching discussion had reminded me of locking. Cheers, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg)
On Sun, Aug 27, 2017 at 04:30:08AM +0200, Andreas Färber wrote: > Am 27.08.2017 um 04:05 schrieb Andrew Lunn: > > n Sun, Aug 27, 2017 at 02:33:27AM +0200, Andreas Färber wrote: > >> +struct rtd119x_rtc { > >> + void __iomem *base; > >> + struct clk *clk; > >> + struct rtc_device *rtcdev; > >> + unsigned base_year; > >> + spinlock_t lock; > > > > Where is this lock initialised? I would expect a call to > > spin_lock_init() somewhere. > > Hm, the spinlock in my irq mux series doesn't have that call either; my > reset driver did have it. The zero initialization appears to work OK, > but you're probably right that it should be there. Hi Andreas I suspect you will have problems if you enable spin lock debug code, like CONFIG_DEBUG_SPINLOCK. Andrew
On 27/08/2017 at 04:30:08 +0200, Andreas Färber wrote: > Am 27.08.2017 um 04:05 schrieb Andrew Lunn: > > n Sun, Aug 27, 2017 at 02:33:27AM +0200, Andreas Färber wrote: > >> +struct rtd119x_rtc { > >> + void __iomem *base; > >> + struct clk *clk; > >> + struct rtc_device *rtcdev; > >> + unsigned base_year; > >> + spinlock_t lock; > > > > Where is this lock initialised? I would expect a call to > > spin_lock_init() somewhere. > > Hm, the spinlock in my irq mux series doesn't have that call either; my > reset driver did have it. The zero initialization appears to work OK, > but you're probably right that it should be there. > > > I also wonder what this lock is protecting, which rtc->ops_lock does > > not protect? > > By that same argument we could ask why so many drivers (and mine, too) > are calling rtc_valid_tm() when __rtc_read_time() calls it again... > Most of them probably predates the introduction of the check in __rtc_read_time(). -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
Hi, Not much to add, apart from the spinlock issue already spotted by Andrew. On 27/08/2017 at 02:33:27 +0200, Andreas Färber wrote: > +struct rtd119x_rtc { > + void __iomem *base; > + struct clk *clk; > + struct rtc_device *rtcdev; > + unsigned base_year; checkpatch complains this should be made unsigned int > + spinlock_t lock; > +}; > + > +static inline int rtd119x_rtc_year_days(int year) > +{ > + return rtc_year_days(1, 12, year); I'm not sure it is worth wrapping rtc_year_days > +static int rtd119x_rtc_read_time(struct device *dev, struct rtc_time *tm) > +{ > + struct rtd119x_rtc *data = dev_get_drvdata(dev); > + unsigned long flags; > + s32 day; > + u32 sec; > + unsigned year; unsigned int > + int tries = 0; > + > + spin_lock_irqsave(&data->lock, flags); > + > + while (true) { > + tm->tm_sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1; > + tm->tm_min = readl_relaxed(data->base + RTD_RTCMIN) & RTD_RTCMIN_RTCMIN_MASK; > + tm->tm_hour = readl_relaxed(data->base + RTD_RTCHR) & RTD_RTCHR_RTCHR_MASK; > + day = readl_relaxed(data->base + RTD_RTCDATE1) & RTD_RTCDATE1_RTCDATE1_MASK; > + day |= (readl_relaxed(data->base + RTD_RTCDATE2) & RTD_RTCDATE2_RTCDATE2_MASK) << 8; > + sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1; > + tries++; > + > + if (sec == tm->tm_sec) > + break; > + > + if (tries >= 3) { > + spin_unlock_irqrestore(&data->lock, flags); > + return -EINVAL; > + } > + } > + if (tries > 1) > + dev_dbg(dev, "%s: needed %i tries\n", __func__, tries); > + > + spin_unlock_irqrestore(&data->lock, flags); > + > + year = data->base_year; > + while (day >= rtd119x_rtc_year_days(year)) { > + day -= rtd119x_rtc_year_days(year); > + year++; > + } > + tm->tm_year = year - 1900; > + tm->tm_yday = day; > + > + tm->tm_mon = 0; > + while (day >= rtc_month_days(tm->tm_mon, year)) { > + day -= rtc_month_days(tm->tm_mon, year); > + tm->tm_mon++; > + } > + tm->tm_mday = day + 1; > + > + return rtc_valid_tm(tm); As you spotted, you can return 0 here. > +} > + > +static int rtd119x_rtc_set_time(struct device *dev, struct rtc_time *tm) > +{ > + struct rtd119x_rtc *data = dev_get_drvdata(dev); > + unsigned long flags; > + unsigned day; ditto -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
Hi Andrew, Am 27.08.2017 um 05:27 schrieb Andrew Lunn: > On Sun, Aug 27, 2017 at 04:30:08AM +0200, Andreas Färber wrote: >> Am 27.08.2017 um 04:05 schrieb Andrew Lunn: >>> n Sun, Aug 27, 2017 at 02:33:27AM +0200, Andreas Färber wrote: >>>> +struct rtd119x_rtc { >>>> + void __iomem *base; >>>> + struct clk *clk; >>>> + struct rtc_device *rtcdev; >>>> + unsigned base_year; >>>> + spinlock_t lock; >>> >>> Where is this lock initialised? I would expect a call to >>> spin_lock_init() somewhere. >> >> Hm, the spinlock in my irq mux series doesn't have that call either; my >> reset driver did have it. The zero initialization appears to work OK, >> but you're probably right that it should be there. > > Hi Andreas > > I suspect you will have problems if you enable spin lock debug code, > like CONFIG_DEBUG_SPINLOCK. Thanks for that hint. Surprisingly the irq mux is still fine with that option enabled, but the rtc now shows: [ 1.193722] BUG: spinlock bad magic on CPU#0, swapper/0/1 [ 1.199264] lock: 0xffff80007bd40db8, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 [ 1.207648] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc6-next-20170825-00061-g88513c6f5687 #180 [ 1.217269] Hardware name: Zidoo X9S (DT) [ 1.221378] Call trace: [ 1.223900] [<ffff0000082878f4>] dump_backtrace+0x0/0x320 [ 1.229439] [<ffff000008287c28>] show_stack+0x14/0x1c [ 1.234622] [<ffff00000875c6ac>] dump_stack+0x94/0xbc [ 1.239804] [<ffff0000082eba4c>] spin_bug+0x84/0xa4 [ 1.244806] [<ffff0000082ebaf8>] do_raw_spin_lock+0x30/0xd4 [ 1.250522] [<ffff000008770868>] _raw_spin_lock_irqsave+0x28/0x38 [ 1.256772] [<ffff00000864cc14>] rtd119x_rtc_read_time+0x24/0x14c [ 1.263019] [<ffff00000864918c>] __rtc_read_time+0x3c/0x64 [ 1.268644] [<ffff0000086491e8>] rtc_read_time+0x34/0x5c [ 1.274091] [<ffff000008649cc8>] __rtc_read_alarm+0x24/0x2f0 [ 1.279893] [<ffff000008648b3c>] rtc_device_register+0xa0/0x144 [ 1.285962] [<ffff000008648d88>] devm_rtc_device_register+0x5c/0xa4 [ 1.292390] [<ffff00000864d038>] rtd119x_rtc_probe+0x174/0x1b4 [ 1.298373] [<ffff000008555038>] platform_drv_probe+0x54/0xa8 [ 1.304265] [<ffff0000085537dc>] driver_probe_device+0x1fc/0x2b8 [ 1.310423] [<ffff00000855390c>] __driver_attach+0x74/0xa4 [ 1.316051] [<ffff000008551d58>] bus_for_each_dev+0x80/0x90 [ 1.321765] [<ffff000008553198>] driver_attach+0x20/0x28 [ 1.327211] [<ffff000008552d8c>] bus_add_driver+0x194/0x1e0 [ 1.332925] [<ffff000008554234>] driver_register+0x98/0xd0 [ 1.338550] [<ffff000008554f90>] __platform_driver_register+0x48/0x50 [ 1.345155] [<ffff0000089924f0>] rtd119x_rtc_driver_init+0x18/0x20 [ 1.351493] [<ffff000008283284>] do_one_initcall+0x118/0x13c [ 1.357299] [<ffff000008970dd0>] kernel_init_freeable+0x220/0x224 [ 1.363548] [<ffff00000876c128>] kernel_init+0x10/0xf8 [ 1.368819] [<ffff000008284200>] ret_from_fork+0x10/0x18 [ 1.375104] rtd1295-rtc 9801b600.rtc: rtc core: registered rtc as rtc0 Will fix. Regards, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg)
Am 27.08.2017 um 10:27 schrieb Alexandre Belloni: > On 27/08/2017 at 04:30:08 +0200, Andreas Färber wrote: >> Am 27.08.2017 um 04:05 schrieb Andrew Lunn: >> By that same argument we could ask why so many drivers (and mine, too) >> are calling rtc_valid_tm() when __rtc_read_time() calls it again... > > Most of them probably predates the introduction of the check in > __rtc_read_time(). Replacing with 0 here then. Regards, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg)
Hi Alexandre, Am 27.08.2017 um 11:13 schrieb Alexandre Belloni: > Not much to add, apart from the spinlock issue already spotted by Andrew. > > On 27/08/2017 at 02:33:27 +0200, Andreas Färber wrote: >> +struct rtd119x_rtc { >> + void __iomem *base; >> + struct clk *clk; >> + struct rtc_device *rtcdev; >> + unsigned base_year; > > checkpatch complains this should be made unsigned int Ouch, I forgot to add my pre-commit hook in this tree and wasn't aware of that rule yet. The RFC had it already. Fixed. >> + spinlock_t lock; >> +}; >> + >> +static inline int rtd119x_rtc_year_days(int year) >> +{ >> + return rtc_year_days(1, 12, year); > > I'm not sure it is worth wrapping rtc_year_days [snip] Well, I found your rtc_year_days rather confusing and had to play with the arguments until I got it working as expected, so I wanted an inline function (or macro) as abstraction from my three callers. Sadly the naming is rather confusing as I am looking for the number of days 365..366, whereas your rtc_year_days is meant to return 0..365 and I would just like to extract the 12th array element but need to counter the -1 subtraction. rtc_year_days(31, 11, year) + 1 is not intuitive either - reads like November (and ranges are not documented). What about exporting a convenient rtc_days_in_year(year) from rtc-lib.c accessing the table directly without rtc_year_days detour? Alternatively an inline function in rtc.h to the same effect without the array? Also despite is_leap_year() returning a bool || expression you keep using it as array index or integer to add. That assumes true == 1, whereas to my knowledge only false is guaranteed to be 0 and any non-zero value means true. So I'd expect the code to be like this: diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c index 1ae7da5cfc60..8983a408fc30 100644 --- a/drivers/rtc/rtc-lib.c +++ b/drivers/rtc/rtc-lib.c @@ -32,7 +32,7 @@ static const unsigned short rtc_ydays[2][13] = { */ int rtc_month_days(unsigned int month, unsigned int year) { - return rtc_days_in_month[month] + (is_leap_year(year) && month == 1); + return rtc_days_in_month[month] + ((is_leap_year(year) && month == 1) ? 1 : 0); } EXPORT_SYMBOL(rtc_month_days); @@ -41,7 +41,7 @@ EXPORT_SYMBOL(rtc_month_days); */ int rtc_year_days(unsigned int day, unsigned int month, unsigned int year) { - return rtc_ydays[is_leap_year(year)][month] + day-1; + return rtc_ydays[is_leap_year(year) ? 1 : 0][month] + day-1; } EXPORT_SYMBOL(rtc_year_days); @@ -69,7 +69,7 @@ void rtc_time64_to_tm(time64_t time, struct rtc_time *tm) - LEAPS_THRU_END_OF(1970 - 1); if (days < 0) { year -= 1; - days += 365 + is_leap_year(year); + days += 365 + (is_leap_year(year) ? 1 : 0); } tm->tm_year = year - 1900; tm->tm_yday = days + 1; The above rtc_time64_to_tm() hunk could be converted to the proposed rtc_days_in_year(). rtc-mcp795.c has another candidate. By reusing rtc_year_days I elegantly avoided is_leap_year in my code, but I could spell out 365 + (is_leap_year(year) ? 1 : 0) in my function if preferred. I dislike duplicating expressions in code. What do you think? Regards, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg)
> >> +static inline int rtd119x_rtc_year_days(int year) > >> +{ > >> + return rtc_year_days(1, 12, year); > > > > I'm not sure it is worth wrapping rtc_year_days > [snip] > > Well, I found your rtc_year_days rather confusing and had to play with > the arguments until I got it working as expected, so I wanted an inline > function (or macro) as abstraction from my three callers. I agree with that. I was wondering why 1st December was being used. I would say this API does not do too well on Rusty's API Design Manifesto. It does at least get the day/month/year in the right order ;-) Andrew
On 27/08/2017 at 15:37:51 +0200, Andrew Lunn wrote: > > >> +static inline int rtd119x_rtc_year_days(int year) > > >> +{ > > >> + return rtc_year_days(1, 12, year); > > > > > > I'm not sure it is worth wrapping rtc_year_days > > [snip] > > > > Well, I found your rtc_year_days rather confusing and had to play with > > the arguments until I got it working as expected, so I wanted an inline > > function (or macro) as abstraction from my three callers. > > I agree with that. I was wondering why 1st December was being used. I > would say this API does not do too well on Rusty's API Design > Manifesto. > It follows the convention that tm_mon is 0-11. Making it easy to read for anyone used to the RTC subsystem. I can agree it is not the most intuitive one. That choice predates the RTC subsystem (made in 1996), I won't give any name ;) > It does at least get the day/month/year in the right order ;-) > > Andrew -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
Hi, On 27/08/2017 at 13:30:59 +0200, Andreas Färber wrote: > Well, I found your rtc_year_days rather confusing and had to play with > the arguments until I got it working as expected, so I wanted an inline > function (or macro) as abstraction from my three callers. > > Sadly the naming is rather confusing as I am looking for the number of > days 365..366, whereas your rtc_year_days is meant to return 0..365 and > I would just like to extract the 12th array element but need to counter > the -1 subtraction. rtc_year_days(31, 11, year) + 1 is not intuitive > either - reads like November (and ranges are not documented). > > What about exporting a convenient rtc_days_in_year(year) from rtc-lib.c > accessing the table directly without rtc_year_days detour? Alternatively > an inline function in rtc.h to the same effect without the array? > This could have been done but what you did in your v3 is fine too. It will always be time to move that to the core later. > Also despite is_leap_year() returning a bool || expression you keep > using it as array index or integer to add. That assumes true == 1, > whereas to my knowledge only false is guaranteed to be 0 and any > non-zero value means true. So I'd expect the code to be like this: sizeof(bool) (actually _Bool) is 1 so it can only be 0 or 1. -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 22efa21b1d81..d5a46f311ecb 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1765,6 +1765,14 @@ config RTC_DRV_CPCAP Say y here for CPCAP rtc found on some Motorola phones and tablets such as Droid 4. +config RTC_DRV_RTD119X + bool "Realtek RTD129x RTC" + depends on ARCH_REALTEK || COMPILE_TEST + default ARCH_REALTEK + help + If you say yes here, you get support for the RTD1295 SoC + Real Time Clock. + comment "HID Sensor RTC drivers" config RTC_DRV_HID_SENSOR_TIME diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index acd366b41c85..55a0a5ca45b0 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -131,6 +131,7 @@ obj-$(CONFIG_RTC_DRV_RP5C01) += rtc-rp5c01.o obj-$(CONFIG_RTC_DRV_RS5C313) += rtc-rs5c313.o obj-$(CONFIG_RTC_DRV_RS5C348) += rtc-rs5c348.o obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o +obj-$(CONFIG_RTC_DRV_RTD119X) += rtc-rtd119x.o obj-$(CONFIG_RTC_DRV_RV3029C2) += rtc-rv3029c2.o obj-$(CONFIG_RTC_DRV_RV8803) += rtc-rv8803.o obj-$(CONFIG_RTC_DRV_RX4581) += rtc-rx4581.o diff --git a/drivers/rtc/rtc-rtd119x.c b/drivers/rtc/rtc-rtd119x.c new file mode 100644 index 000000000000..27fa68a5af30 --- /dev/null +++ b/drivers/rtc/rtc-rtd119x.c @@ -0,0 +1,254 @@ +/* + * Realtek RTD129x RTC + * + * Copyright (c) 2017 Andreas Färber + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> +#include <linux/spinlock.h> + +#define RTD_RTCSEC 0x00 +#define RTD_RTCMIN 0x04 +#define RTD_RTCHR 0x08 +#define RTD_RTCDATE1 0x0c +#define RTD_RTCDATE2 0x10 +#define RTD_RTCACR 0x28 +#define RTD_RTCEN 0x2c +#define RTD_RTCCR 0x30 + +#define RTD_RTCSEC_RTCSEC_MASK 0x7f + +#define RTD_RTCMIN_RTCMIN_MASK 0x3f + +#define RTD_RTCHR_RTCHR_MASK 0x1f + +#define RTD_RTCDATE1_RTCDATE1_MASK 0xff + +#define RTD_RTCDATE2_RTCDATE2_MASK 0x7f + +#define RTD_RTCACR_RTCPWR BIT(7) + +#define RTD_RTCEN_RTCEN_MASK 0xff + +#define RTD_RTCCR_RTCRST BIT(6) + +struct rtd119x_rtc { + void __iomem *base; + struct clk *clk; + struct rtc_device *rtcdev; + unsigned base_year; + spinlock_t lock; +}; + +static inline int rtd119x_rtc_year_days(int year) +{ + return rtc_year_days(1, 12, year); +} + +static void rtd119x_rtc_reset(struct device *dev) +{ + struct rtd119x_rtc *data = dev_get_drvdata(dev); + u32 val; + + val = readl_relaxed(data->base + RTD_RTCCR); + val |= RTD_RTCCR_RTCRST; + writel_relaxed(val, data->base + RTD_RTCCR); + + val &= ~RTD_RTCCR_RTCRST; + writel(val, data->base + RTD_RTCCR); +} + +static void rtd119x_rtc_set_enabled(struct device *dev, bool enable) +{ + struct rtd119x_rtc *data = dev_get_drvdata(dev); + u32 val; + + val = readl_relaxed(data->base + RTD_RTCEN); + if (enable) { + if ((val & RTD_RTCEN_RTCEN_MASK) == 0x5a) + return; + writel_relaxed(0x5a, data->base + RTD_RTCEN); + } else { + writel_relaxed(0, data->base + RTD_RTCEN); + } +} + +static int rtd119x_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct rtd119x_rtc *data = dev_get_drvdata(dev); + unsigned long flags; + s32 day; + u32 sec; + unsigned year; + int tries = 0; + + spin_lock_irqsave(&data->lock, flags); + + while (true) { + tm->tm_sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1; + tm->tm_min = readl_relaxed(data->base + RTD_RTCMIN) & RTD_RTCMIN_RTCMIN_MASK; + tm->tm_hour = readl_relaxed(data->base + RTD_RTCHR) & RTD_RTCHR_RTCHR_MASK; + day = readl_relaxed(data->base + RTD_RTCDATE1) & RTD_RTCDATE1_RTCDATE1_MASK; + day |= (readl_relaxed(data->base + RTD_RTCDATE2) & RTD_RTCDATE2_RTCDATE2_MASK) << 8; + sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1; + tries++; + + if (sec == tm->tm_sec) + break; + + if (tries >= 3) { + spin_unlock_irqrestore(&data->lock, flags); + return -EINVAL; + } + } + if (tries > 1) + dev_dbg(dev, "%s: needed %i tries\n", __func__, tries); + + spin_unlock_irqrestore(&data->lock, flags); + + year = data->base_year; + while (day >= rtd119x_rtc_year_days(year)) { + day -= rtd119x_rtc_year_days(year); + year++; + } + tm->tm_year = year - 1900; + tm->tm_yday = day; + + tm->tm_mon = 0; + while (day >= rtc_month_days(tm->tm_mon, year)) { + day -= rtc_month_days(tm->tm_mon, year); + tm->tm_mon++; + } + tm->tm_mday = day + 1; + + return rtc_valid_tm(tm); +} + +static int rtd119x_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct rtd119x_rtc *data = dev_get_drvdata(dev); + unsigned long flags; + unsigned day; + int i; + + if (1900 + tm->tm_year < data->base_year) + return -EINVAL; + + day = 0; + for (i = data->base_year; i < 1900 + tm->tm_year; i++) + day += rtd119x_rtc_year_days(i); + + day += tm->tm_yday; + if (day > 0x7fff) + return -EINVAL; + + spin_lock_irqsave(&data->lock, flags); + + rtd119x_rtc_set_enabled(dev, false); + + writel_relaxed((tm->tm_sec << 1) & RTD_RTCSEC_RTCSEC_MASK, data->base + RTD_RTCSEC); + writel_relaxed(tm->tm_min & RTD_RTCMIN_RTCMIN_MASK, data->base + RTD_RTCMIN); + writel_relaxed(tm->tm_hour & RTD_RTCHR_RTCHR_MASK, data->base + RTD_RTCHR); + writel_relaxed(day & RTD_RTCDATE1_RTCDATE1_MASK, data->base + RTD_RTCDATE1); + writel_relaxed((day >> 8) & RTD_RTCDATE2_RTCDATE2_MASK, data->base + RTD_RTCDATE2); + + rtd119x_rtc_set_enabled(dev, true); + + spin_unlock_irqrestore(&data->lock, flags); + + return 0; +} + +static const struct rtc_class_ops rtd119x_rtc_ops = { + .read_time = rtd119x_rtc_read_time, + .set_time = rtd119x_rtc_set_time, +}; + +static const struct of_device_id rtd119x_rtc_dt_ids[] = { + { .compatible = "realtek,rtd1295-rtc" }, + { } +}; + +static int rtd119x_rtc_probe(struct platform_device *pdev) +{ + struct rtd119x_rtc *data; + struct resource *res; + u32 val; + int ret; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + platform_set_drvdata(pdev, data); + data->base_year = 2014; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + data->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(data->base)) + return PTR_ERR(data->base); + + data->clk = of_clk_get(pdev->dev.of_node, 0); + if (IS_ERR(data->clk)) + return PTR_ERR(data->clk); + + ret = clk_prepare_enable(data->clk); + if (ret) { + clk_put(data->clk); + return ret; + } + + val = readl_relaxed(data->base + RTD_RTCACR); + if (!(val & RTD_RTCACR_RTCPWR)) { + writel_relaxed(RTD_RTCACR_RTCPWR, data->base + RTD_RTCACR); + + rtd119x_rtc_reset(&pdev->dev); + + writel_relaxed(0, data->base + RTD_RTCMIN); + writel_relaxed(0, data->base + RTD_RTCHR); + writel_relaxed(0, data->base + RTD_RTCDATE1); + writel_relaxed(0, data->base + RTD_RTCDATE2); + } + + rtd119x_rtc_set_enabled(&pdev->dev, true); + + data->rtcdev = devm_rtc_device_register(&pdev->dev, "rtc", + &rtd119x_rtc_ops, THIS_MODULE); + if (IS_ERR(data->rtcdev)) { + dev_err(&pdev->dev, "failed to register rtc device"); + clk_disable_unprepare(data->clk); + clk_put(data->clk); + return PTR_ERR(data->rtcdev); + } + + return 0; +} + +static int rtd119x_rtc_remove(struct platform_device *pdev) +{ + struct rtd119x_rtc *data = platform_get_drvdata(pdev); + + rtd119x_rtc_set_enabled(&pdev->dev, false); + + clk_disable_unprepare(data->clk); + + return 0; +} + +static struct platform_driver rtd119x_rtc_driver = { + .probe = rtd119x_rtc_probe, + .remove = rtd119x_rtc_remove, + .driver = { + .name = "rtd1295-rtc", + .of_match_table = rtd119x_rtc_dt_ids, + }, +}; +builtin_platform_driver(rtd119x_rtc_driver);
Based on QNAP's arch/arm/mach-rtk119x/driver/rtk_rtc_drv.c code and mach-rtk119x/driver/dc2vo/fpga/include/mis_reg.h register definitions. The base year 2014 was observed on all of Zidoo X9S, ProBox2 Ava and Beelink Lake I. Signed-off-by: Andreas Färber <afaerber@suse.de> --- v1 -> v2: * Dropped open/release in favor of probe/remove (Alexandre) * read_time: Reordered register accesses (Alexandre) * read_time/set_time: Refactored day calculations to avoid time64_t (Alexandre) * read_time: Retry if seconds change (Alexandre) * probe: Added missing RTCACR initialization code * set_time: Fixed year check (off by 1900) * set_time: Fixed new seconds (off by factor two) * Cleaned up debug output (Andrew) * Added spinlocks around register accesses * Added masks for register fields drivers/rtc/Kconfig | 8 ++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-rtd119x.c | 254 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 263 insertions(+) create mode 100644 drivers/rtc/rtc-rtd119x.c -- 2.12.3