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path: root/drivers/clk/bcm/clk-bcm2835.c
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2017-06-02clk: bcm2835: Minimise clock jitter for PCM clockPhil Elwell1-5/+29
Fractional clock dividers generate accurate average frequencies but with jitter, particularly when the integer divisor is small. Introduce a new metric of clock accuracy to penalise clocks with a good average but worse jitter compared to clocks with an average which is no better but with lower jitter. The metric is the ideal rate minus the worse deviation from that ideal using the nearest integer divisors. Use this metric for parent selection for clocks requiring low jitter (currently just PCM). Signed-off-by: Phil Elwell <phil@raspberrypi.org> Reviewed-by: Eric Anholt <eric@anholt.net> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-06-02clk: bcm2835: Limit PCM clock to OSC and PLLD_PERPhil Elwell1-1/+26
Restrict clock sources for the PCM peripheral to the oscillator and PLLD_PER because other source may have varying rates or be switched off. Prevent other sources from being selected by replacing their names in the list of potential parents with dummy entries (entry index is significant). Signed-off-by: Phil Elwell <phil@raspberrypi.org> Reviewed-by: Eric Anholt <eric@anholt.net> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-06-02clk: bcm2835: Correct the prediv logicPhil Elwell1-1/+3
If a clock has the prediv flag set, both the integer and fractional parts must be scaled when calculating the resulting frequency. Signed-off-by: Phil Elwell <phil@raspberrypi.org> Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-01-20clk: bcm2835: Add leaf clock measurement support, disabled by defaultEric Anholt1-25/+119
This proved incredibly useful during debugging of the DSI driver, to see if our clocks were running at rate we requested. Let's leave it here for the next person interacting with clocks on the platform (and so that hopefully we can just hook it up to debugfs some day). Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-01-20clk: bcm2835: Register the DSI0/DSI1 pixel clocks.Eric Anholt1-12/+109
The DSI pixel clocks are muxed from clocks generated in the analog phy by the DSI driver. In order to set them as parents, we need to do the same name lookup dance on them as we do for our root oscillator. Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-01-20clk: bcm2835: Don't rate change PLLs on behalf of DSI PLL dividers.Eric Anholt1-14/+28
Our core PLLs are intended to be configured once and left alone. With the SET_RATE_PARENT, asking to set the PLLD_DSI1 clock rate would change PLLD just to get closer to the requested DSI clock, thus changing PLLD_PER, the UART and ethernet PHY clock rates downstream of it, and breaking ethernet. We *do* want PLLH to change so that PLLH_AUX can be exactly the value we want, though. Thus, we need to have a per-divider policy of whether to pass rate changes up. Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-12-12clk: bcm: Fix 'maybe-uninitialized' warning in ↵Boris Brezillon1-1/+1
bcm2835_clock_choose_div_and_prate() best_rate is reported as potentially uninitialized by gcc. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Fixes: 155e8b3b0ee3 ("clk: bcm: Support rate change propagation on bcm2835 clocks") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-12-08clk: bcm: Allow rate change propagation to PLLH_AUX on VEC clockBoris Brezillon1-1/+6
The VEC clock requires needs to be set at exactly 108MHz. Allow rate change propagation on PLLH_AUX to match this requirement wihtout impacting other IPs (PLLH is currently only used by the HDMI encoder, which cannot be enabled when the VEC encoder is enabled). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-12-08clk: bcm: Support rate change propagation on bcm2835 clocksBoris Brezillon1-4/+63
Some peripheral clocks, like the VEC (Video EnCoder) clock need to be set to a precise rate (in our case 108MHz). With the current implementation, where peripheral clocks are not allowed to forward rate change requests to their parents, it is impossible to match this requirement unless the bootloader has configured things correctly, or a specific rate has been assigned through the DT (with the assigned-clk-rates property). Add a new field to struct bcm2835_clock_data to specify which parent clocks accept rate change propagation, and support set rate propagation in bcm2835_clock_determine_rate(). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-12-08clk: bcm2835: Avoid overwriting the div info when disabling a pll_div clkBoris Brezillon1-1/+3
bcm2835_pll_divider_off() is resetting the divider field in the A2W reg to zero when disabling the clock. Make sure we preserve this value by reading the previous a2w_reg value first and ORing the result with A2W_PLL_CHANNEL_DISABLE. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the audio domain clocks") Cc: <stable@vger.kernel.org> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-11-23clk: bcm2835: Fix ->fixed_divider of pllh_auxBoris Brezillon1-1/+1
There is no fixed divider on pllh_aux. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-10-17clk: bcm2835: Clamp the PLL's requested rate to the hardware limits.Eric Anholt1-7/+4
Fixes setting low-resolution video modes on HDMI. Now the PLLH_PIX divider adjusts itself until the PLLH is within bounds. Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-09-14clk: bcm2835: Migrate to clk_hw based registration and OF APIsStephen Boyd1-39/+46
Now that we have clk_hw based provider APIs to register clks, we can get rid of struct clk pointers while registering clks in these drivers, allowing us to move closer to a clear split of consumer and provider clk APIs. Cc: Eric Anholt <eric@anholt.net> Cc: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
2016-09-07clk: bcm2835: Skip PLLC clocks when deciding on a new clock parentEric Anholt1-0/+23
If the firmware had set up a clock to source from PLLC, go along with it. But if we're looking for a new parent, we don't want to switch it to PLLC because the firmware will force PLLC (and thus the AXI bus clock) to different frequencies during over-temp/under-voltage, without notification to Linux. On my system, this moves the Linux-enabled HDMI state machine and DSI1 escape clock over to plld_per from pllc_per. EMMC still ends up on pllc_per, because the firmware had set it up to use that. Signed-off-by: Eric Anholt <eric@anholt.net> Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the audio domain clocks") Acked-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-09-07clk: bcm2835: Mark the CM SDRAM clock's parent as criticalEric Anholt1-0/+25
While the SDRAM is being driven by its dedicated PLL most of the time, there is a little loop running in the firmware that periodically turns on the CM SDRAM clock (using its pre-initialized parent) and switches SDRAM to using the CM clock to do PVT recalibration. This avoids system hangs if we choose SDRAM's parent for some other clock, then disable that clock. Signed-off-by: Eric Anholt <eric@anholt.net> Acked-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-09-07clk: bcm2835: Mark GPIO clocks enabled at boot as criticalEric Anholt1-1/+9
These divide off of PLLD_PER and are used for the ethernet and wifi PHYs source PLLs. Neither of them is currently represented by a phy device that would grab the clock for us. This keeps other drivers from killing the networking PHYs when they disable their own clocks and trigger PLLD_PER's refcount going to 0. Signed-off-by: Eric Anholt <eric@anholt.net> Acked-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-09-07clk: bcm2835: Mark the VPU clock as criticalEric Anholt1-1/+4
The VPU clock is also the clock for our AXI bus, so we really can't disable it. This might have happened during boot if, for example, uart1 (aux_uart clock) probed and was then disabled before the other consumers of the VPU clock had probed. Signed-off-by: Eric Anholt <eric@anholt.net> Acked-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-04-19clk: bcm2835: Fix PLL poweronEric Anholt1-0/+4
In poweroff, we set the reset bit and the power down bit, but only managed to unset the reset bit for poweron. This meant that if HDMI did -EPROBE_DEFER after it had grabbed its clocks, we'd power down the PLLH (that had been on at boot time) and never recover. Signed-off-by: Eric Anholt <eric@anholt.net> Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the audio domain clocks") Cc: stable@vger.kernel.org Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-04-19clk: bcm2835: Fix compiler warnings on 64-bit buildsEric Anholt1-4/+4
Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-03-17clk: bcm2835: add missing osc and per clocksMartin Sperl1-0/+90
Add AVE0, DFT, GP0, GP1, GP2, SLIM, SMI, TEC, DPI, CAM0, CAM1, DSI0E, and DSI1E. PULSE is not added because it has an extra divider. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Eric Anholt <eric@anholt.net>
2016-03-17clk: bcm2835: add missing PLL clock dividersMartin Sperl1-0/+32
Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Eric Anholt <eric@anholt.net>
2016-03-17clk: bcm2835: enable management of PCM clockMartin Sperl1-0/+7
Enable the PCM clock in the SOC, which is used by the bcm2835-i2s driver. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Eric Anholt <eric@anholt.net>
2016-03-17clk: bcm2835: reorganize bcm2835_clock_array assignmentMartin Sperl1-459/+393
Reorganize bcm2835_clock_array so that there is no more need for separate bcm2835_*_data structures to be defined. Instead the required structures are generated inline via helper macros. To allow this to also work for pll alone it was required that the parent_pll was changed from a pointer to bcm2835_pll_data to the name of the pll instead. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Eric Anholt <eric@anholt.net>
2016-03-17clk: bcm2835: remove use of BCM2835_CLOCK_COUNT in driverMartin Sperl1-73/+94
As the use of BCM2835_CLOCK_COUNT in include/dt-bindings/clock/bcm2835.h is frowned upon as it needs to get modified every time a new clock gets introduced this patch changes the clk-bcm2835 driver to use a different scheme for registration of clocks and pll, so that there is no more need for BCM2835_CLOCK_COUNT to be defined. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Eric Anholt <eric@anholt.net>
2016-03-17clk: bcm2835: expose raw clock-registers via debugfsMartin Sperl1-0/+101
For debugging purposes under some circumstance it helps to be able to see the actual clock registers. E.g: when looking at the clock divider it is helpful to see what the actual clock divider is. This patch exposes all the clock registers specific to each clock/pll/pll-divider via debugfs. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net> Acked-by: Eric Anholt <eric@anholt.net>
2016-03-17clk: bcm2835: clean up coding style issuesMartin Sperl1-6/+2
Fix all the checkpatch complaints for clk-bcm2835.c Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net>
2016-03-17clk: bcm2835: correctly enable fractional clock supportMartin Sperl1-6/+39
The current driver calculates the clock divider with fractional support enabled. But it does not enable fractional support in the control register itself resulting in an integer only divider, but in clk_set_rate responds back the fractionally divided clock frequency. This patch enables fractional support in the control register whenever there is a fractional bit set in the requested clock divider. Mash clock limits are are also handled for the PWM clock applying the correct divider limits (2 and max_int) applicable to basic fractional divider support (mash order of 1). It also adds locking to protect the read/modify/write cycle of the register modification. Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the audio domain clocks") Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Eric Anholt <eric@anholt.net>
2016-03-17clk: bcm2835: divider value has to be 1 or moreMartin Sperl1-2/+3
Current clamping of a normal divider allows a value < 1 to be valid. A divider of < 1 would actually only be possible if we had a PLL... So this patch clamps the divider to 1. Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the audio domain clocks") Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Eric Anholt <eric@anholt.net>
2016-03-17clk: bcm2835: add locking to pll*_on/off methodsMartin Sperl1-0/+4
Add missing locking to: * bcm2835_pll_divider_on * bcm2835_pll_divider_off to protect the read modify write cycle for the register access protecting both cm_reg and a2w_reg registers. Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the audio domain clocks") Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Eric Anholt <eric@anholt.net>
2016-03-17clk: bcm2835: pll_off should only update CM_PLL_ANARSTMartin Sperl1-2/+8
bcm2835_pll_off is currently assigning CM_PLL_ANARST to the control register, which may lose the other bits that are currently set by the clock dividers. It also now locks during the read/modify/write cycle of both registers. Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the audio domain clocks") Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Eric Anholt <eric@anholt.net>
2016-03-02clk: bcm: Remove CLK_IS_ROOTStephen Boyd1-6/+3
This flag is a no-op now. Remove usage of the flag. Cc: Lee Jones <lee@kernel.org> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-25clk: bcm2835: added missing clock register definitionsMartin Sperl1-0/+13
Added missing CTRL and DIV clock register definitions for: PCM, SLIM, TCNT, TEC, TD0, TD1 Register information taken from: https://rawgit.com/msperl/rpi-registers/master/rpi-registers.html#CM which extracted the information from the header files shared by Broadcom/rpi foundation in this file: http://www.broadcom.com/docs/support/videocore/Brcm_Android_ICS_Graphics_Stack.tar.gz Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-16clk: bcm2835: Reuse CLK_DIVIDER_MAX_AT_ZERO for recalc_rate()Eric Anholt1-11/+2
We were rolling this ourselves, but clk-divider can do it now. Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2016-02-16clk: bcm2835: Fix setting of PLL divider clock ratesEric Anholt1-5/+7
Our dividers weren't being set successfully because CM_PASSWORD wasn't included in the register write. It looks easier to just compute the divider to write ourselves than to update clk-divider for the ability to OR in some arbitrary bits on write. Fixes about half of the video modes on my HDMI monitor (everything except 720x400). Cc: stable@vger.kernel.org Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-12-24clk: bcm2835: Add PWM clock supportRemi Pommarel1-0/+13
Register the pwm clock for bcm2835. Signed-off-by: Remi Pommarel <repk@triplefau.lt> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-12-24clk: bcm2835: Support for clock parent selectionRemi Pommarel1-45/+77
Some bcm2835 clocks used by hardware (like "PWM" or "H264") can have multiple parent clocks. These clocks divide the rate of a parent which can be selected by setting the proper bits in the clock control register. Previously all these parents where handled by a mux clock. But a mux clock cannot be used because updating clock control register to select parent needs a password to be xor'd with the parent index. This patch get rid of mux clock and make these clocks handle their own parent, allowing them to select the one to use. Signed-off-by: Remi Pommarel <repk@triplefau.lt> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-12-24clk: bcm2835: add a round up ability to the clock divisorRemi Pommarel1-10/+12
Make bcm2835_clock_choose_div to optionally round up the chosen MASH divisor so that the resulting average rate will not be higher than the requested one. Signed-off-by: Remi Pommarel <repk@triplefau.lt> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-10-12clk: bcm2835: Add support for programming the audio domain clocksEric Anholt1-1/+1521
This adds support for enabling, disabling, and setting the rate of the audio domain clocks. It will be necessary for setting the pixel clock for HDMI in the VC4 driver and let us write a cpufreq driver. It will also improve compatibility with user changes to the firmware's config.txt, since our previous fixed clocks are unaware of it. The firmware also has support for configuring the clocks through the mailbox channel, but the pixel clock setup by the firmware doesn't work, and it's Raspberry Pi specific anyway. The only conflicts we should have with the firmware would be if we made firmware calls that result in clock management (like opening firmware V3D or ISP access, which we don't support in upstream), or on hardware over-thermal or under-voltage (when the firmware would rewrite PLLB to take the ARM out of overclock). If that happens, our cached .recalc_rate() results would be incorrect, but that's no worse than our current state where we used fixed clocks. The existing fixed clocks in the code are left in place to provide backwards compatibility with old device tree files. Signed-off-by: Eric Anholt <eric@anholt.net> Tested-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-01clk: bcm2835: Move under bcm/ with other Broadcom SoC clk drivers.Eric Anholt1-0/+55
clk-bcm2835.c predates the drivers under bcm/, but all the new BCM drivers are going in there so let's follow them. Signed-off-by: Eric Anholt <eric@anholt.net> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
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