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path: root/drivers/clk/clk-fractional-divider.c
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2017-08-08clk: fractional-divider: allow overriding of approximationElaine Zhang1-8/+20
Fractional dividers may have special requirements concerning numerator and denominator selection that differ from just getting the best approximation. For example on Rockchip socs the denominator must be at least 20 times larger than the numerator to generate precise clock frequencies. Therefore add the ability to provide custom approximation functions. Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com> Acked-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
2016-04-20clk: fractional-divider: Add hw based registration APIsStephen Boyd1-5/+35
Add registration APIs in the clk fractional divider code to return struct clk_hw pointers instead of struct clk pointers. This way we hide the struct clk pointer from providers unless they need to use consumer facing APIs. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-01-29clk: move the common clock's to_clk_*(_hw) macros to clk-provider.hGeliang Tang1-2/+0
to_clk_*(_hw) macros have been repeatedly defined in many places. This patch moves all the to_clk_*(_hw) definitions in the common clock framework to public header clk-provider.h, and drop the local definitions. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-02clk: fractional-divider: switch to rational best approximationAndy Shevchenko1-15/+26
This patch converts the code to use rational best approximation algorithm which is much more precise. Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-02clk: fractional-divider: keep mwidth and nwidth internallyAndy Shevchenko1-2/+4
The patch adds mwidth and nwidth fields to the struct clk_fractional_divider for further usage. While here, use GENMASK() instead of open coding this functionality. Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-02clk: fractional-divider: rename prate -> parent_rateAndy Shevchenko1-5/+5
Rename function parameter to be more explicit what it is for. This also makes it in align with struct clk_ops. There is no functional change. Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28clk: basic-type: Silence warnings about lock imbalancesStephen Boyd1-0/+8
The basic clock types use conditional locking for the register accessor spinlocks. Add __acquire() and __release() markings in the right locations so that sparse isn't tripped up on the conditional locking. drivers/clk/clk-mux.c:68:12: warning: context imbalance in 'clk_mux_set_parent' - different lock contexts for basic block drivers/clk/clk-divider.c:379:12: warning: context imbalance in 'clk_divider_set_rate' - different lock contexts for basic block drivers/clk/clk-gate.c:71:9: warning: context imbalance in 'clk_gate_endisable' - different lock contexts for basic block drivers/clk/clk-fractional-divider.c:36:9: warning: context imbalance in 'clk_fd_recalc_rate' - different lock contexts for basic block drivers/clk/clk-fractional-divider.c:68:12: warning: context imbalance in 'clk_fd_set_rate' - different lock contexts for basic block Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-15clk: basic-types: Remove useless allocation failure printksStephen Boyd1-3/+1
Printing an error on kmalloc() failures is unnecessary. Remove the print and use *ptr in sizeof() for future-proof code. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-12clk: fractional-divider: support for divider bypassingHeikki Krogerus1-0/+3
If the divider or multiplier values are 0 in the register, bypassing the divider and returning the parent clock rate in clk_fd_recalc_rate(). Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org> [mturquette@linaro.org: fixed commitlog typo]
2014-09-10clk: fractional-divider: cast parent_rate to u64 before multiplyingHeiko Stübner1-1/+1
On 32bit architectures, like ARM calculating the fractional rate will do the multiplication before converting the value to u64 when it gets assigned to ret, which can produce overflows. The error in question happened with a parent_rate of 386MHz, m = 3000, n = 60000, which resulted in a wrong rate value of 15812Hz. Therefore cast parent_rate to u64 to make sure the multiplication happens in a 64bit space and produces the correct 192MHz in the example. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-05-20clk: new basic clk type for fractional dividerHeikki Krogerus1-0/+135
Fractional divider clocks are fairly common. This adds basic type for them. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Mike Turquette <mturquette@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>