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  • Boris Brezillon's avatar
    clk: change clk_ops' ->determine_rate() prototype · 0817b62c
    Boris Brezillon authored
    
    
    Clock rates are stored in an unsigned long field, but ->determine_rate()
    (which returns a rounded rate from a requested one) returns a long
    value (errors are reported using negative error codes), which can lead
    to long overflow if the clock rate exceed 2Ghz.
    
    Change ->determine_rate() prototype to return 0 or an error code, and pass
    a pointer to a clk_rate_request structure containing the expected target
    rate and the rate constraints imposed by clk users.
    
    The clk_rate_request structure might be extended in the future to contain
    other kind of constraints like the rounding policy, the maximum clock
    inaccuracy or other things that are not yet supported by the CCF
    (power consumption constraints ?).
    
    Signed-off-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
    CC: Jonathan Corbet <corbet@lwn.net>
    CC: Tony Lindgren <tony@atomide.com>
    CC: Ralf Baechle <ralf@linux-mips.org>
    CC: "Emilio López" <emilio@elopez.com.ar>
    CC: Maxime Ripard <maxime.ripard@free-electrons.com>
    Acked-by: default avatarTero Kristo <t-kristo@ti.com>
    CC: Peter De Schrijver <pdeschrijver@nvidia.com>
    CC: Prashant Gaikwad <pgaikwad@nvidia.com>
    CC: Stephen Warren <swarren@wwwdotorg.org>
    CC: Thierry Reding <thierry.reding@gmail.com>
    CC: Alexandre Courbot <gnurou@gmail.com>
    CC: linux-doc@vger.kernel.org
    CC: linux-kernel@vger.kernel.org
    CC: linux-arm-kernel@lists.infradead.org
    CC: linux-omap@vger.kernel.org
    CC: linux-mips@linux-mips.org
    CC: linux-tegra@vger.kernel.org
    [sboyd@codeaurora.org: Fix parent dereference problem in
    __clk_determine_rate()]
    Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
    Tested-by: default avatarRomain Perier <romain.perier@gmail.com>
    Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
    [sboyd@codeaurora.org: Folded in fix from Heiko for fixed-rate
    clocks without parents or a rate determining op]
    Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
    0817b62c