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Commit 8e6a4c40 authored by Emilio López's avatar Emilio López Committed by Maxime Ripard
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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: default avatarEmilio López <emilio@elopez.com.ar>
Signed-off-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
parent 12ef06af

drivers/clk/sunxi/clk-sunxi.c

+28 −0
Original line number Diff line number Diff line
@@ -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();

}