[PATCH v7 07/12] clk: tegra: Workaround for Tegra114 MSENC problem

From: Peter De Schrijver
Date: Fri Feb 15 2013 - 07:44:15 EST


Workaround a hardware bug in MSENC during clock enable.

Signed-off-by: Peter De Schrijver <pdeschrijver@xxxxxxxxxx>
---
drivers/clk/tegra/clk-periph-gate.c | 9 +++++++++
drivers/clk/tegra/clk.h | 2 ++
2 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/clk/tegra/clk-periph-gate.c b/drivers/clk/tegra/clk-periph-gate.c
index 6dd5332..c9083fb 100644
--- a/drivers/clk/tegra/clk-periph-gate.c
+++ b/drivers/clk/tegra/clk-periph-gate.c
@@ -43,6 +43,8 @@ static DEFINE_SPINLOCK(periph_ref_lock);

#define periph_clk_to_bit(periph) (1 << (gate->clk_num % 32))

+#define LVL2_CLK_GATE_OVRE 0x554
+
/* Peripheral gate clock ops */
static int clk_periph_is_enabled(struct clk_hw *hw)
{
@@ -83,6 +85,13 @@ static int clk_periph_enable(struct clk_hw *hw)
}
}

+ if (gate->flags & TEGRA_PERIPH_WAR_1005168) {
+ writel_relaxed(0, gate->clk_base + LVL2_CLK_GATE_OVRE);
+ writel_relaxed(BIT(22), gate->clk_base + LVL2_CLK_GATE_OVRE);
+ udelay(1);
+ writel_relaxed(0, gate->clk_base + LVL2_CLK_GATE_OVRE);
+ }
+
spin_unlock_irqrestore(&periph_ref_lock, flags);

return 0;
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index 4c4bf9a..fa21c88 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -356,6 +356,7 @@ struct tegra_clk_periph_regs {
* TEGRA_PERIPH_ON_APB - If peripheral is in the APB bus then read the
* bus to flush the write operation in apb bus. This flag indicates
* that this peripheral is in apb bus.
+ * TEGRA_PERIPH_WAR_1005168 - Apply workaround for Tegra114 MSENC bug
*/
struct tegra_clk_periph_gate {
u32 magic;
@@ -375,6 +376,7 @@ struct tegra_clk_periph_gate {
#define TEGRA_PERIPH_NO_RESET BIT(0)
#define TEGRA_PERIPH_MANUAL_RESET BIT(1)
#define TEGRA_PERIPH_ON_APB BIT(2)
+#define TEGRA_PERIPH_WAR_1005168 BIT(3)

void tegra_periph_reset(struct tegra_clk_periph_gate *gate, bool assert);
extern const struct clk_ops tegra_clk_periph_gate_ops;
--
1.7.1

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