Sorry,
forgot to add RFC since I didn't test these patches yet.
anyways, this is the new version of the omap_clk_associate()
mechanism. The patch header will have to change, just saw it.
Paul, could you take a look at it, does it look better now ?
I dropped the third argument (function name) since we should
be matching only against the consumer device, if the consumer
device is correct, it doesn't matter which name we give to
clk_get().
On Sat, Oct 25, 2008 at 10:55:46PM +0300, Felipe Balbi wrote:
> From: Felipe Balbi <felipe.balbi@xxxxxxxxx>
>
> Introduce a new mechanism to omap's clk implementation to
> associate the device with its clock during platform_device
> registration. Also gives the clock a function name (like
> mmc_fck, uart_fck, ehci_fck, etc) so drivers won't have to
> care about clk names any longer.
>
> With this mechanism we can also be sure drivers won't be able
> to clk_get the wrong clk (only true when we move all drivers
> to this new mechanism and drop the old ones).
>
> Clk's function names will be defined as they come necessary
> but let's try to keep it as simple as possible.
>
> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxx>
> ---
> arch/arm/plat-omap/clock.c | 47 ++++++++++++++++++++++++++++--
> arch/arm/plat-omap/include/mach/clock.h | 4 ++
> 2 files changed, 47 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/plat-omap/clock.c b/arch/arm/plat-omap/clock.c
> index 5178701..083a3ff 100644
> --- a/arch/arm/plat-omap/clock.c
> +++ b/arch/arm/plat-omap/clock.c
> @@ -44,6 +44,7 @@ static struct clk_functions *arch_clock;
> struct clk * clk_get(struct device *dev, const char *id)
> {
> struct clk *p, *clk = ERR_PTR(-ENOENT);
> + struct device *d;
> int idno;
>
> if (dev == NULL || dev->bus != &platform_bus_type)
> @@ -54,27 +55,65 @@ struct clk * clk_get(struct device *dev, const char *id)
> mutex_lock(&clocks_mutex);
>
> list_for_each_entry(p, &clocks, node) {
> + list_for_each_entry(d, &p->consumers, node) {
> + if (dev == d) {
> + clk = p;
> + break;
> + }
> + }
> +
> if (p->id == idno &&
> strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
> clk = p;
> - goto found;
> + break;
> }
> - }
>
> - list_for_each_entry(p, &clocks, node) {
> if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
> clk = p;
> break;
> }
> }
here I merged both list_for_each_entry() in only one to make it a bit
cheaper. Hope there's no problem with it.
>
> -found:
> mutex_unlock(&clocks_mutex);
>
> return clk;
> }
> EXPORT_SYMBOL(clk_get);
>
> +/**
> + * omap_clk_associate - associates a clock to its consumer device(s)
> + * @id: clock id as defined in arch/arm/mach-omapX/clkxxxx.h
> + * @dev: device pointer for the clock consumer
> + *
> + * This function attempts to simplify clock handling for device drivers
> + * by letting struct clk know which device is the correct consumer for
> + * that clock. By making this trick, we let drivers get the correct
> + * clock without knowing about different clock names between omap
> + * versions.
> + */
> +void __init omap_clk_associate(const char *id, struct device *dev)
> +{
> + struct clk *clk = clk_get(NULL, id);
> +
> + if (!clk || IS_ERR(clk)) {
> + pr_debug("%s: unable to get clock\n", __func__);
> + return;
> + }
> +
> + if (!dev) {
> + pr_debug("%s: missing device to associate with\n", __func__);
> + clk_put(clk);
> + return;
> + }
> +
> + if (list_empty(&clk->consumers))
> + INIT_LIST_HEAD(&clk->consumers);
this I need to test. I didn't know about other mechanism to see if
clk->consumers wasn't initialized so I used list_empty(). I need to see
if it won't break in runtime.
> +
> + /* add device to consumer list */
> + list_add(&dev->node, &clk->consumers);
> + clk_put(clk);
> +};
> +
> int clk_enable(struct clk *clk)
> {
> unsigned long flags;
> diff --git a/arch/arm/plat-omap/include/mach/clock.h b/arch/arm/plat-omap/include/mach/clock.h
> index 9088925..1600a14 100644
> --- a/arch/arm/plat-omap/include/mach/clock.h
> +++ b/arch/arm/plat-omap/include/mach/clock.h
> @@ -13,6 +13,8 @@
> #ifndef __ARCH_ARM_OMAP_CLOCK_H
> #define __ARCH_ARM_OMAP_CLOCK_H
>
> +#include <linux/device.h>
> +
> struct module;
> struct clk;
> struct clockdomain;
> @@ -61,6 +63,7 @@ struct dpll_data {
>
> struct clk {
> struct list_head node;
> + struct list_head consumers;
> struct module *owner;
> const char *name;
> int id;
> @@ -116,6 +119,7 @@ struct clk_functions {
>
> extern unsigned int mpurate;
>
> +extern void omap_clk_associate(const char *id, struct device *dev);
> extern int clk_init(struct clk_functions *custom_clocks);
> extern int clk_register(struct clk *clk);
> extern void clk_unregister(struct clk *clk);
> --
> 1.6.0.2.307.gc427
--
balbi
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