From 4472e1849db7f719bbf625890096e0269b5849fe Mon Sep 17 00:00:00 2001 From: Michael Tretter Date: Thu, 21 Jan 2021 08:16:53 +0100 Subject: soc: xilinx: vcu: make pll post divider explicit According to the downstream driver documentation due to timing constraints the output divider of the PLL has to be set to 1/2. Add a helper function for that check instead of burying the code in one large setup function. The bit is undocumented and marked as reserved in the register reference. Signed-off-by: Michael Tretter Acked-by: Michal Simek Link: https://lore.kernel.org/r/20210121071659.1226489-10-m.tretter@pengutronix.de Signed-off-by: Stephen Boyd --- drivers/soc/xilinx/xlnx_vcu.c | 52 ++++++++++++++++++++++++++++++------------- 1 file changed, 36 insertions(+), 16 deletions(-) diff --git a/drivers/soc/xilinx/xlnx_vcu.c b/drivers/soc/xilinx/xlnx_vcu.c index e38e9c8325a7..9e410d7ffd08 100644 --- a/drivers/soc/xilinx/xlnx_vcu.c +++ b/drivers/soc/xilinx/xlnx_vcu.c @@ -72,6 +72,7 @@ * @logicore_reg_ba: logicore reg base address * @vcu_slcr_ba: vcu_slcr Register base address * @pll: handle for the VCU PLL + * @pll_post: handle for the VCU PLL post divider * @clk_data: clocks provided by the vcu clock provider */ struct xvcu_device { @@ -81,6 +82,7 @@ struct xvcu_device { struct regmap *logicore_reg_ba; void __iomem *vcu_slcr_ba; struct clk_hw *pll; + struct clk_hw *pll_post; struct clk_hw_onecell_data *clk_data; }; @@ -274,6 +276,29 @@ static int xvcu_pll_wait_for_lock(struct xvcu_device *xvcu) return -ETIMEDOUT; } +static struct clk_hw *xvcu_register_pll_post(struct device *dev, + const char *name, + const struct clk_hw *parent_hw, + void __iomem *reg_base) +{ + u32 div; + u32 vcu_pll_ctrl; + + /* + * The output divider of the PLL must be set to 1/2 to meet the + * timing in the design. + */ + vcu_pll_ctrl = xvcu_read(reg_base, VCU_PLL_CTRL); + div = vcu_pll_ctrl >> VCU_PLL_CTRL_CLKOUTDIV_SHIFT; + div = div & VCU_PLL_CTRL_CLKOUTDIV_MASK; + if (div != 1) + return ERR_PTR(-EINVAL); + + return clk_hw_register_fixed_factor(dev, "vcu_pll_post", + clk_hw_get_name(parent_hw), + CLK_SET_RATE_PARENT, 1, 2); +} + static const struct xvcu_pll_cfg *xvcu_find_cfg(int div) { const struct xvcu_pll_cfg *cfg = NULL; @@ -402,7 +427,7 @@ static int xvcu_set_vcu_pll_info(struct xvcu_device *xvcu) { u32 refclk, coreclk, mcuclk, inte, deci; u32 divisor_mcu, divisor_core, fvco; - u32 clkoutdiv, vcu_pll_ctrl, pll_clk; + u32 pll_clk; u32 mod; int i; int ret; @@ -425,19 +450,6 @@ static int xvcu_set_vcu_pll_info(struct xvcu_device *xvcu) dev_dbg(xvcu->dev, "Core clock from logicoreIP is %uHz\n", coreclk); dev_dbg(xvcu->dev, "Mcu clock from logicoreIP is %uHz\n", mcuclk); - /* - * The divide-by-2 should be always enabled (==1) - * to meet the timing in the design. - * Otherwise, it's an error - */ - vcu_pll_ctrl = xvcu_read(xvcu->vcu_slcr_ba, VCU_PLL_CTRL); - clkoutdiv = vcu_pll_ctrl >> VCU_PLL_CTRL_CLKOUTDIV_SHIFT; - clkoutdiv = clkoutdiv & VCU_PLL_CTRL_CLKOUTDIV_MASK; - if (clkoutdiv != 1) { - dev_err(xvcu->dev, "clkoutdiv value is invalid\n"); - return -EINVAL; - } - for (i = ARRAY_SIZE(xvcu_pll_cfg) - 1; i >= 0; i--) { const struct xvcu_pll_cfg *cfg = &xvcu_pll_cfg[i]; @@ -484,7 +496,7 @@ static int xvcu_set_vcu_pll_info(struct xvcu_device *xvcu) hw = clk_hw_register_fixed_rate(xvcu->dev, "vcu_pll", __clk_get_name(xvcu->pll_ref), - 0, pll_clk); + 0, fvco); if (IS_ERR(hw)) return PTR_ERR(hw); xvcu->pll = hw; @@ -607,6 +619,7 @@ static int xvcu_register_clock_provider(struct xvcu_device *xvcu) struct clk_parent_data parent_data[2] = { 0 }; struct clk_hw_onecell_data *data; struct clk_hw **hws; + struct clk_hw *hw; void __iomem *reg_base = xvcu->vcu_slcr_ba; data = devm_kzalloc(dev, struct_size(data, hws, CLK_XVCU_NUM_CLOCKS), GFP_KERNEL); @@ -617,8 +630,13 @@ static int xvcu_register_clock_provider(struct xvcu_device *xvcu) xvcu->clk_data = data; + hw = xvcu_register_pll_post(dev, "vcu_pll_post", xvcu->pll, reg_base); + if (IS_ERR(hw)) + return PTR_ERR(hw); + xvcu->pll_post = hw; + parent_data[0].fw_name = "pll_ref"; - parent_data[1].hw = xvcu->pll; + parent_data[1].hw = xvcu->pll_post; hws[CLK_XVCU_ENC_CORE] = xvcu_clk_hw_register_leaf(dev, "venc_core_clk", @@ -657,6 +675,8 @@ static void xvcu_unregister_clock_provider(struct xvcu_device *xvcu) xvcu_clk_hw_unregister_leaf(hws[CLK_XVCU_ENC_MCU]); if (!IS_ERR_OR_NULL(hws[CLK_XVCU_ENC_CORE])) xvcu_clk_hw_unregister_leaf(hws[CLK_XVCU_ENC_CORE]); + + clk_hw_unregister_fixed_factor(xvcu->pll_post); } /** -- cgit v1.2.3-59-g8ed1b