From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: [PATCH 3/4] clk: Provide always-on clock support Date: Fri, 27 Feb 2015 21:14:33 +0000 Message-ID: <1425071674-16995-4-git-send-email-lee.jones@linaro.org> References: <1425071674-16995-1-git-send-email-lee.jones@linaro.org> Return-path: In-Reply-To: <1425071674-16995-1-git-send-email-lee.jones@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: lee.jones@linaro.org, kernel@stlinux.com, mturquette@linaro.org, sboyd@codeaurora.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org Lots of platforms contain clocks which if turned off would prove fatal. The only way to recover from these catastrophic failures is to restart the board(s). Now, when a clock is registered with the framework it is compared against a list of provided always-on clock names which must be kept ungated. If it matches, we enable the existing CLK_IGNORE_UNUSED flag, which will prevent the common clk framework from attempting to gate it during the clk_disable_unused() procedure. Signed-off-by: Lee Jones --- drivers/clk/clk.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 61c3fc5..3aab75e 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2856,6 +2856,9 @@ int of_clk_add_provider(struct device_node *np, void *data) { struct of_clk_provider *cp; + struct property *prop; + struct clk *clk; + const char *clkname; int ret; cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); @@ -2875,6 +2878,14 @@ int of_clk_add_provider(struct device_node *np, if (ret < 0) of_clk_del_provider(np); + of_property_for_each_string(np, "clock-always-on", prop, clkname) { + clk = __clk_lookup(clkname); + if (!clk) + continue; + + clk->core->flags |= CLK_IGNORE_UNUSED; + } + return ret; } EXPORT_SYMBOL_GPL(of_clk_add_provider); -- 1.9.1