diff options
author | Emilio López <emilio@elopez.com.ar> | 2013-09-20 22:03:12 -0300 |
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committer | Maxime Ripard <maxime.ripard@free-electrons.com> | 2013-11-10 11:39:55 +0100 |
commit | 8e6a4c40bb6f3866548811f9f3882a627293fc2f (patch) | |
tree | 74927c0c89b29a9e3f60d10666ae4a215c74e5e4 /drivers/clk/sunxi | |
parent | 12ef06afb3959e7f6f2ae8917c4750883a3e8c14 (diff) | |
download | blackbird-op-linux-8e6a4c40bb6f3866548811f9f3882a627293fc2f.tar.gz blackbird-op-linux-8e6a4c40bb6f3866548811f9f3882a627293fc2f.zip |
clk: sunxi: protect core clocks from accidental shutdown
Some important clocks may get disabled as a side effect of another clock
being disabled, because they have no consumers. This patch implements a
mechanism so those clocks can be claimed by the driver and therefore
remain enabled at all times.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Diffstat (limited to 'drivers/clk/sunxi')
-rw-r--r-- | drivers/clk/sunxi/clk-sunxi.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c index 34ee69f4d50c..83d3eace3ebc 100644 --- a/drivers/clk/sunxi/clk-sunxi.c +++ b/drivers/clk/sunxi/clk-sunxi.c @@ -617,6 +617,31 @@ static void __init of_sunxi_table_clock_setup(const struct of_device_id *clk_mat } } +/** + * System clock protection + * + * By enabling these critical clocks, we prevent their accidental gating + * by the framework + */ +static void __init sunxi_clock_protect(void) +{ + struct clk *clk; + + /* memory bus clock - sun5i+ */ + clk = clk_get(NULL, "mbus"); + if (!IS_ERR(clk)) { + clk_prepare_enable(clk); + clk_put(clk); + } + + /* DDR clock - sun4i+ */ + clk = clk_get(NULL, "pll5_ddr"); + if (!IS_ERR(clk)) { + clk_prepare_enable(clk); + clk_put(clk); + } +} + void __init sunxi_init_clocks(void) { /* Register all the simple and basic clocks on DT */ @@ -633,4 +658,7 @@ void __init sunxi_init_clocks(void) /* Register gate clocks */ of_sunxi_table_clock_setup(clk_gates_match, sunxi_gates_clk_setup); + + /* Enable core system clocks */ + sunxi_clock_protect(); } |