From 86bcfa2e87c42b8af77188e7a939e952199d4da1 Mon Sep 17 00:00:00 2001 From: Mike Turquette Date: Mon, 24 Feb 2014 16:08:41 -0800 Subject: clk: add pr_debug & kerneldoc around clk notifiers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Both the pr_err and the additional kerneldoc aim to help when debugging errors thrown from within a clock rate-change notifier callback. Reported-by: Sören Brinkmann Acked-by: Sören Brinkmann Signed-off-by: Mike Turquette --- include/linux/clk.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux') diff --git a/include/linux/clk.h b/include/linux/clk.h index 0dd91148165..fb5e097d8f7 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -78,8 +78,22 @@ struct clk_notifier_data { unsigned long new_rate; }; +/** + * clk_notifier_register: register a clock rate-change notifier callback + * @clk: clock whose rate we are interested in + * @nb: notifier block with callback function pointer + * + * ProTip: debugging across notifier chains can be frustrating. Make sure that + * your notifier callback function prints a nice big warning in case of + * failure. + */ int clk_notifier_register(struct clk *clk, struct notifier_block *nb); +/** + * clk_notifier_unregister: unregister a clock rate-change notifier callback + * @clk: clock whose rate we are no longer interested in + * @nb: notifier block which will be unregistered + */ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb); /** -- cgit v1.2.3-70-g09d2 From c646cbf10fb3347ecda290dfce96b813a423ca07 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Fri, 21 Mar 2014 06:43:56 -0500 Subject: clk: support hardware-specific debugfs entries Add a new clk_ops->debug_init method to allow a clock hardware driver to populate the clock's debugfs directory with entries beyond those common for every clock. Signed-off-by: Alex Elder Signed-off-by: Mike Turquette --- drivers/clk/clk.c | 4 ++++ include/linux/clk-provider.h | 8 ++++++++ 2 files changed, 12 insertions(+) (limited to 'include/linux') diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index fb3c40b4fbe..1fbcb2b107e 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -277,6 +277,10 @@ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) if (!d) goto err_out; + if (clk->ops->debug_init) + if (clk->ops->debug_init(clk->hw, clk->dentry)) + goto err_out; + ret = 0; goto out; diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 939533da93a..511917416fb 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -32,6 +32,7 @@ #define CLK_GET_ACCURACY_NOCACHE BIT(8) /* do not use the cached clk accuracy */ struct clk_hw; +struct dentry; /** * struct clk_ops - Callback operations for hardware clocks; these are to @@ -127,6 +128,12 @@ struct clk_hw; * separately via calls to .set_parent and .set_rate. * Returns 0 on success, -EERROR otherwise. * + * @debug_init: Set up type-specific debugfs entries for this clock. This + * is called once, after the debugfs directory entry for this + * clock has been created. The dentry pointer representing that + * directory is provided as an argument. Called with + * prepare_lock held. Returns 0 on success, -EERROR otherwise. + * * * The clk_enable/clk_disable and clk_prepare/clk_unprepare pairs allow * implementations to split any work between atomic (enable) and sleepable @@ -165,6 +172,7 @@ struct clk_ops { unsigned long (*recalc_accuracy)(struct clk_hw *hw, unsigned long parent_accuracy); void (*init)(struct clk_hw *hw); + int (*debug_init)(struct clk_hw *hw, struct dentry *dentry); }; /** -- cgit v1.2.3-70-g09d2