On Fri, Oct 14, 2011 at 11:14:19AM -0700, Turquette, Mike wrote: > On Thu, Sep 22, 2011 at 3:26 PM, Mike Turquette <mturque...@ti.com> wrote: > > From: Jeremy Kerr <jeremy.k...@canonical.com> > > struct clk_hw_ops { > > int (*prepare)(struct clk_hw *); > > void (*unprepare)(struct clk_hw *); > > int (*enable)(struct clk_hw *); > > void (*disable)(struct clk_hw *); > > unsigned long (*recalc_rate)(struct clk_hw *); > > In implementing recalc for divider clocks, I started to wonder, "why > not just pass struct clk *clk into the clk_hw_ops func ptrs?". > > recalc is an obvious example whereby we need access to parent->rate. > The code usually ends up looking something like: > > unsigned long omap_recalc_rate(struct clk_hw *hw) > { > struct clk *parent; > struct clk_hw_omap *oclk; > > parent = hw->clk->parent; clk drivers can not see struct clk details. I use clk_get_parent. > oclk = to_clk_omap(hw); > ... > } > > That's a bit of a song and dance to have to do in almost every op, and > often these ops will need access to stuff like clk->rate also. Is > there any opposition to just passing in struct clk? e.g: > > unsigned long omap_recalc_rate(struct clk *clk) > { > struct clk *parent; > struct clk_hw_omap *oclk; > > parent = clk->parent; > oclk = to_clk_omap(clk->hw); > ... > } In my understanding, struct clk stores things specific to clk core, struct clk_hw stores common things needed by clk drivers. For static clk driver there' some problems: - For clocks without mux, I need duplicate a .parent and set .get_parent. Even when we adopt DT and dynamicly create clk, it's still a problem. Moving .parent to clk_hw can fix it. - When I define a clk array, I don't need to find another place to store .ops. It's not problem for dynamic creating clock. - As I mentioned in another mail, clk group need no lock version prepare/unprepare and enable/disable functions Another way is, add a "{struct clk_hw *clks; int count}" in clk_hw, let clk core handle it. I prefer the second way, but I'm not sure whether it's common enough. It's still a problem for dynamic creating clock.
Thanks Richard > > It is a small nitpick, but it affects the API for everybody so best to > get it right now before folks start migrating over to it. > > Thanks, > Mike > > > int (*set_rate)(struct clk_hw *, > > unsigned long, unsigned long *); > > long (*round_rate)(struct clk_hw *, unsigned long); > > int (*set_parent)(struct clk_hw *, struct clk *); > > struct clk * (*get_parent)(struct clk_hw *); > > }; > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-ker...@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev