[PATCH 2/3] zte: clk: pd_bit is not 0 on zx296718
From: shawnguo@kernel.org (Shawn Guo)
Date: 2017-03-21 08:38:22
Also in:
linux-clk
Subsystem:
common clk framework, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Linus Torvalds
From: Shawn Guo <redacted> The bit 0 of PLL_CFG0 register is not powerdown on zx296718, but part of of postdiv2 field. The consequence is that functions like hw_to_idx() and zx_pll_enable() will end up tampering the postdiv2 of the PLL. Let's fix it by defining pd_bit 0xff which is obviously invalid for a bit position and having PLL driver check the validity before operating on the bit. Signed-off-by: Shawn Guo <redacted> --- drivers/clk/zte/clk.c | 12 +++++++++++- drivers/clk/zte/clk.h | 6 +++++- 2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/zte/clk.c b/drivers/clk/zte/clk.c
index 878d879b23ff..b82031766ffa 100644
--- a/drivers/clk/zte/clk.c
+++ b/drivers/clk/zte/clk.c@@ -52,7 +52,10 @@ static int hw_to_idx(struct clk_zx_pll *zx_pll) /* For matching the value in lookup table */ hw_cfg0 &= ~BIT(zx_pll->lock_bit); - hw_cfg0 |= BIT(zx_pll->pd_bit); + + /* Check availability of pd_bit */ + if (zx_pll->pd_bit < 32) + hw_cfg0 |= BIT(zx_pll->pd_bit); for (i = 0; i < zx_pll->count; i++) { if (hw_cfg0 == config[i].cfg0 && hw_cfg1 == config[i].cfg1)
@@ -108,6 +111,10 @@ static int zx_pll_enable(struct clk_hw *hw) struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw); u32 reg; + /* If pd_bit is not available, simply return success. */ + if (zx_pll->pd_bit > 31) + return 0; + reg = readl_relaxed(zx_pll->reg_base); writel_relaxed(reg & ~BIT(zx_pll->pd_bit), zx_pll->reg_base);
@@ -120,6 +127,9 @@ static void zx_pll_disable(struct clk_hw *hw) struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw); u32 reg; + if (zx_pll->pd_bit > 31) + return; + reg = readl_relaxed(zx_pll->reg_base); writel_relaxed(reg | BIT(zx_pll->pd_bit), zx_pll->reg_base); }
diff --git a/drivers/clk/zte/clk.h b/drivers/clk/zte/clk.h
index 84a55a3e2bd4..4df0f121b56d 100644
--- a/drivers/clk/zte/clk.h
+++ b/drivers/clk/zte/clk.h@@ -66,8 +66,12 @@ struct clk_zx_pll { CLK_GET_RATE_NOCACHE), \ } +/* + * The pd_bit is not available on ZX296718, so let's pass something + * bigger than 31, e.g. 0xff, to indicate that. + */ #define ZX296718_PLL(_name, _parent, _reg, _table) \ -ZX_PLL(_name, _parent, _reg, _table, 0, 30) +ZX_PLL(_name, _parent, _reg, _table, 0xff, 30) struct zx_clk_gate { struct clk_gate gate;
--
1.9.1