On Wed, Aug 22, 2018 at 6:52 AM Abel Vesa <abel.vesa@xxxxxxx> wrote:
>
> From: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
>
> The SCCG is a new PLL type introduced on i.MX8. Add support for this.
> The driver currently misses the PLL lock check, as the preliminary
> documentation mentions lock configurations, but is quiet about where
> to find the actual lock status signal.
>
> Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> Signed-off-by: Abel Vesa <abel.vesa@xxxxxxx>
> ---
> drivers/clk/imx/Makefile | 3 +-
> drivers/clk/imx/clk-sccg-pll.c | 231 +++++++++++++++++++++++++++++++++++++++++
> drivers/clk/imx/clk.h | 9 ++
> 3 files changed, 242 insertions(+), 1 deletion(-)
> create mode 100644 drivers/clk/imx/clk-sccg-pll.c
>
> diff --git a/drivers/clk/imx/Makefile b/drivers/clk/imx/Makefile
> index 4893c1f..b87513c 100644
> --- a/drivers/clk/imx/Makefile
> +++ b/drivers/clk/imx/Makefile
> @@ -12,7 +12,8 @@ obj-y += \
> clk-pllv1.o \
> clk-pllv2.o \
> clk-pllv3.o \
> - clk-pfd.o
> + clk-pfd.o \
> + clk-sccg-pll.o
>
> obj-$(CONFIG_SOC_IMX1) += clk-imx1.o
> obj-$(CONFIG_SOC_IMX21) += clk-imx21.o
> diff --git a/drivers/clk/imx/clk-sccg-pll.c b/drivers/clk/imx/clk-sccg-pll.c
> new file mode 100644
> index 0000000..886ae03
> --- /dev/null
> +++ b/drivers/clk/imx/clk-sccg-pll.c
> @@ -0,0 +1,231 @@
> +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> +/*
> + * Copyright 2018 NXP.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +
> +#include "clk.h"
> +
> +/* PLL CFGs */
> +#define PLL_CFG0 0x0
> +#define PLL_CFG1 0x4
> +#define PLL_CFG2 0x8
> +
> +#define PLL_DIVF1_SHIFT 13
> +#define PLL_DIVF2_SHIFT 7
> +#define PLL_DIVF_MASK 0x3f
> +
> +#define PLL_DIVR1_SHIFT 25
> +#define PLL_DIVR2_SHIFT 19
> +#define PLL_DIVR1_MASK 0x3
> +#define PLL_DIVR2_MASK 0x3f
> +#define PLL_REF_SHIFT 0
> +#define PLL_REF_MASK 0x3
> +
> +#define PLL_LOCK 31
> +#define PLL_PD 7
> +
> +#define OSC_25M 25000000
> +#define OSC_27M 27000000
> +
> +struct clk_sccg_pll {
> + struct clk_hw hw;
> + void __iomem *base;
> +};
> +
> +#define to_clk_sccg_pll(_hw) container_of(_hw, struct clk_sccg_pll, hw)
> +
> +static int clk_pll1_is_prepared(struct clk_hw *hw)
> +{
> + struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
> + u32 val;
> +
> + val = readl_relaxed(pll->base + PLL_CFG0);
> + return (val & (1 << PLL_PD)) ? 0 : 1;
> +}
> +
> +static unsigned long clk_pll1_recalc_rate(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
> + u32 val, divf;
> +
> + val = readl_relaxed(pll->base + PLL_CFG2);
> + divf = (val >> PLL_DIVF1_SHIFT) & PLL_DIVF_MASK;
> +
> + return parent_rate * 2 * (divf + 1);
> +}
> +
> +static long clk_pll1_round_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long *prate)
> +{
> + unsigned long parent_rate = *prate;
> + u32 div;
> +
> + div = rate / (parent_rate * 2);
> +
> + return parent_rate * div * 2;
> +}
> +
> +static int clk_pll1_set_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long parent_rate)
> +{
> + struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
> + u32 val;
> + u32 divf;
> +
> + divf = rate / (parent_rate * 2);
> +
> + val = readl_relaxed(pll->base + PLL_CFG2);
> + val &= ~(PLL_DIVF_MASK << PLL_DIVF1_SHIFT);
> + val |= (divf - 1) << PLL_DIVF1_SHIFT;
> + writel_relaxed(val, pll->base + PLL_CFG2);
> +
> + /* FIXME: PLL lock check */
> +
> + return 0;
> +}
> +
> +static int clk_pll1_prepare(struct clk_hw *hw)
> +{
> + struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
> + u32 val;
> +
> + val = readl_relaxed(pll->base);
> + val &= ~(1 << PLL_PD);
> + writel_relaxed(val, pll->base);
> +
> + /* FIXME: PLL lock check */
> +
> + return 0;
> +}
> +
> +static void clk_pll1_unprepare(struct clk_hw *hw)
> +{
> + struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
> + u32 val;
> +
> + val = readl_relaxed(pll->base);
> + val |= (1 << PLL_PD);
> + writel_relaxed(val, pll->base);
> +}
> +
> +static unsigned long clk_pll2_recalc_rate(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
> + u32 val, ref, divr1, divf1, divr2, divf2;
> + u64 temp64;
> +
> + val = readl_relaxed(pll->base + PLL_CFG0);
> + switch ((val >> PLL_REF_SHIFT) & PLL_REF_MASK) {
> + case 0:
> + ref = OSC_25M;
> + break;
> + case 1:
> + ref = OSC_27M;
> + break;
> + default:
> + ref = OSC_25M;
> + break;
> + }
> +
> + val = readl_relaxed(pll->base + PLL_CFG2);
> + divr1 = (val >> PLL_DIVR1_SHIFT) & PLL_DIVR1_MASK;
> + divr2 = (val >> PLL_DIVR2_SHIFT) & PLL_DIVR2_MASK;
> + divf1 = (val >> PLL_DIVF1_SHIFT) & PLL_DIVF_MASK;
> + divf2 = (val >> PLL_DIVF2_SHIFT) & PLL_DIVF_MASK;
> +
> + temp64 = ref * 2;
> + temp64 *= (divf1 + 1) * (divf2 + 1);
> +
> + do_div(temp64, (divr1 + 1) * (divr2 + 1));
> +
> + return (unsigned long)temp64;
> +}
> +
> +static long clk_pll2_round_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long *prate)
> +{
> + u32 div;
> + unsigned long parent_rate = *prate;
> +
> + div = rate / (parent_rate);
> +
> + return parent_rate * div;
> +}
> +
> +static int clk_pll2_set_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long parent_rate)
> +{
> + u32 val;
> + u32 divf;
> + struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
> +
> + divf = rate / (parent_rate);
> +
> + val = readl_relaxed(pll->base + PLL_CFG2);
> + val &= ~(PLL_DIVF_MASK << PLL_DIVF2_SHIFT);
> + val |= (divf - 1) << PLL_DIVF2_SHIFT;
> + writel_relaxed(val, pll->base + PLL_CFG2);
> +
> + /* FIXME: PLL lock check */
> +
> + return 0;
> +}
> +
> +static const struct clk_ops clk_sccg_pll1_ops = {
> + .is_prepared = clk_pll1_is_prepared,
> + .recalc_rate = clk_pll1_recalc_rate,
> + .round_rate = clk_pll1_round_rate,
> + .set_rate = clk_pll1_set_rate,
> +};
> +
> +static const struct clk_ops clk_sccg_pll2_ops = {
> + .prepare = clk_pll1_prepare,
> + .unprepare = clk_pll1_unprepare,
> + .recalc_rate = clk_pll2_recalc_rate,
> + .round_rate = clk_pll2_round_rate,
> + .set_rate = clk_pll2_set_rate,
> +};
> +
> +struct clk *imx_clk_sccg_pll(const char *name,
> + const char *parent_name,
> + void __iomem *base,
> + enum imx_sccg_pll_type pll_type)
> +{
> + struct clk_sccg_pll *pll;
> + struct clk *clk;
> + struct clk_init_data init;
> +
> + pll = kzalloc(sizeof(*pll), GFP_KERNEL);
> + if (!pll)
> + return ERR_PTR(-ENOMEM);
> +
> + pll->base = base;
> + init.name = name;
> + switch (pll_type) {
> + case SCCG_PLL1:
> + init.ops = &clk_sccg_pll1_ops;
> + break;
> + case SCCG_PLL2:
> + init.ops = &clk_sccg_pll2_ops;
> + break;
> + }
Please add error checking in the switch above since it's pretty clear
that a wrong kind of argument can be passed as a pll_type without it
being noticeable.
Thanks,
Andrey Smirnov
