Subject: [PATCH v2 3/4] clk: imx: add SCCG PLL type

From: [email-masked] (Shawn Guo)
Date: Fri, 23 Feb 2018 16:46:15 +0800

On Thu, Feb 01, 2018 at 06:54:11PM +0100, Lucas Stach wrote:
> 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 <[email-masked]>
> ---
>  drivers/clk/imx/Makefile       |   3 +-
>  drivers/clk/imx/clk-sccg-pll.c | 235 +++++++++++++++++++++++++++++++++++++++++
>  drivers/clk/imx/clk.h          |   9 ++
>  3 files changed, 246 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 9892ae63539c..bfcbd5272d12 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 000000000000..3a79f952564b
> --- /dev/null
> +++ b/drivers/clk/imx/clk-sccg-pll.c
> @@ -0,0 +1,235 @@
> +/*
> + * Copyright 2017 NXP.
> + *
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +#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)

I found the indentation of multi-lines arguments is strange, i.e. it
always missing one space.  Please check.

> +{
> +	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);

Unnecessary parentheses.

> +	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;

Can we consistently sort variables lines from the long ones to the
short?

> +
> +	div = rate / (parent_rate);

Unnecessary parentheses.

> +
> +	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);

Ditto

Shawn

> +
> +	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;
> +	}
> +
> +	init.flags = 0;
> +	init.parent_names = &parent_name;
> +	init.num_parents = 1;
> +
> +	pll->hw.init = &init;
> +
> +	clk = clk_register(NULL, &pll->hw);
> +	if (IS_ERR(clk))
> +		kfree(pll);
> +
> +	return clk;
> +}
> diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h
> index 287610902ea8..809509758e24 100644
> --- a/drivers/clk/imx/clk.h
> +++ b/drivers/clk/imx/clk.h
> @@ -21,6 +21,11 @@ enum imx_pllv1_type {
>  	IMX_PLLV1_IMX35,
>  };
>  
> +enum imx_sccg_pll_type {
> +	SCCG_PLL1,
> +	SCCG_PLL2,
> +};
> +
>  struct clk *imx_clk_pllv1(enum imx_pllv1_type type, const char *name,
>  		const char *parent, void __iomem *base);
>  
> @@ -30,6 +35,10 @@ struct clk *imx_clk_pllv2(const char *name, const char *parent,
>  struct clk *imx_clk_frac_pll(const char *name, const char *parent_name,
>  			     void __iomem *base);
>  
> +struct clk *imx_clk_sccg_pll(const char *name, const char *parent_name,
> +			     void __iomem *base,
> +			     enum imx_sccg_pll_type pll_type);
> +
>  enum imx_pllv3_type {
>  	IMX_PLLV3_GENERIC,
>  	IMX_PLLV3_SYS,
> -- 
> 2.15.1
>