target/linux/sunxi/patches-3.13/103-sunxi-clk-core-clock-protect.patch

   1 From 7df19a0adca7806e081479eecb07365652c26ef5 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Emilio=20L=C3=B3pez?= <emilio@elopez.com.ar>
   3 Date: Fri, 20 Sep 2013 22:03:12 -0300
   4 Subject: [PATCH] clk: sunxi: protect core clocks from accidental shutdown
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Some important clocks may get disabled as a side effect of another clock
  10 being disabled, because they have no consumers. This patch implements a
  11 mechanism so those clocks can be claimed by the driver and therefore
  12 remain enabled at all times.
  13
  14 Signed-off-by: Emilio López <emilio@elopez.com.ar>
  15 Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
  16
  17 Conflicts:
  18         drivers/clk/sunxi/clk-sunxi.c
  19 ---
  20  drivers/clk/sunxi/clk-sunxi.c | 28 ++++++++++++++++++++++++++++
  21  1 file changed, 28 insertions(+)
  22
  23 diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
  24 index 9bbd035..8fc1375 100644
  25 --- a/drivers/clk/sunxi/clk-sunxi.c
  26 +++ b/drivers/clk/sunxi/clk-sunxi.c
  27 @@ -616,6 +616,31 @@ static void __init of_sunxi_table_clock_setup(const struct of_device_id *clk_mat
  28         }
  29  }
  30
  31 +/**
  32 + * System clock protection
  33 + *
  34 + * By enabling these critical clocks, we prevent their accidental gating
  35 + * by the framework
  36 + */
  37 +static void __init sunxi_clock_protect(void)
  38 +{
  39 +       struct clk *clk;
  40 +
  41 +       /* memory bus clock - sun5i+ */
  42 +       clk = clk_get(NULL, "mbus");
  43 +       if (!IS_ERR(clk)) {
  44 +               clk_prepare_enable(clk);
  45 +               clk_put(clk);
  46 +       }
  47 +
  48 +       /* DDR clock - sun4i+ */
  49 +       clk = clk_get(NULL, "pll5_ddr");
  50 +       if (!IS_ERR(clk)) {
  51 +               clk_prepare_enable(clk);
  52 +               clk_put(clk);
  53 +       }
  54 +}
  55 +
  56  static void __init sunxi_init_clocks(struct device_node *np)
  57  {
  58         /* Register factor clocks */
  59 @@ -629,6 +654,9 @@ static void __init sunxi_init_clocks(struct device_node *np)
  60
  61         /* Register gate clocks */
  62         of_sunxi_table_clock_setup(clk_gates_match, sunxi_gates_clk_setup);
  63 +
  64 +       /* Enable core system clocks */
  65 +       sunxi_clock_protect();
  66  }
  67  CLK_OF_DECLARE(sun4i_a10_clk_init, "allwinner,sun4i-a10", sunxi_init_clocks);
  68  CLK_OF_DECLARE(sun5i_a10s_clk_init, "allwinner,sun5i-a10s", sunxi_init_clocks);
  69 --
  70 1.8.5.1
  71