Date:   Sun, 29 Jan 2023 19:36:18 +0200
From:   Abel Vesa <abel.vesa@linaro.org>
To:     Oleksij Rempel <o.rempel@pengutronix.de>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Abel Vesa <abelvesa@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Richard Cochran <richardcochran@gmail.com>,
        kernel@pengutronix.de, Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        Russell King <linux@armlinux.org.uk>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-clk@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH v2 01/19] clk: imx: add clk-gpr-mux driver
Message-ID: <Y9aukmQwiwzpakYo@linaro.org>
References: <20230117061453.3723649-1-o.rempel@pengutronix.de>
 <20230117061453.3723649-2-o.rempel@pengutronix.de>
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Precedence: bulk

On 23-01-17 07:14:35, Oleksij Rempel wrote:
> Almost(?) every i'MX variant has clk mux for ethernet (rgmii/rmii) reference

i.MX

> clock located in the GPR1 register. So far this clk is configured in
> different ways:
> - mach-imx6q is doing mux configuration based on ptp vs enet_ref clk
>   comparison.
> - mach-imx7d is setting mux to PAD for all boards
> - mach-imx6ul is setting mux to internal clock for all boards.
> 
> Since we have imx7d and imx6ul board variants which do not work with
> configurations forced by kernel mach code, we need to implement this clk
> mux properly as part of the clk framework. Which is done by this patch.
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>

Reviewed-by: Abel Vesa <abel.vesa@linaro.org>

> ---
>  drivers/clk/imx/Makefile      |   1 +
>  drivers/clk/imx/clk-gpr-mux.c | 119 ++++++++++++++++++++++++++++++++++
>  drivers/clk/imx/clk.h         |   5 ++
>  3 files changed, 125 insertions(+)
>  create mode 100644 drivers/clk/imx/clk-gpr-mux.c
> 
> diff --git a/drivers/clk/imx/Makefile b/drivers/clk/imx/Makefile
> index e8aacb0ee6ac..a75d59f7cb8a 100644
> --- a/drivers/clk/imx/Makefile
> +++ b/drivers/clk/imx/Makefile
> @@ -22,6 +22,7 @@ mxc-clk-objs += clk-pllv3.o
>  mxc-clk-objs += clk-pllv4.o
>  mxc-clk-objs += clk-pll14xx.o
>  mxc-clk-objs += clk-sscg-pll.o
> +mxc-clk-objs += clk-gpr-mux.o
>  obj-$(CONFIG_MXC_CLK) += mxc-clk.o
>  
>  obj-$(CONFIG_CLK_IMX8MM) += clk-imx8mm.o
> diff --git a/drivers/clk/imx/clk-gpr-mux.c b/drivers/clk/imx/clk-gpr-mux.c
> new file mode 100644
> index 000000000000..47a3e3cdcc82
> --- /dev/null
> +++ b/drivers/clk/imx/clk-gpr-mux.c
> @@ -0,0 +1,119 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + */
> +
> +#define pr_fmt(fmt) "imx:clk-gpr-mux: " fmt
> +
> +#include <linux/module.h>
> +
> +#include <linux/clk-provider.h>
> +#include <linux/errno.h>
> +#include <linux/export.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
> +
> +#include "clk.h"
> +
> +struct imx_clk_gpr {
> +	struct clk_hw hw;
> +	struct regmap *regmap;
> +	u32 mask;
> +	u32 reg;
> +	const u32 *mux_table;
> +};
> +
> +static struct imx_clk_gpr *to_imx_clk_gpr(struct clk_hw *hw)
> +{
> +	return container_of(hw, struct imx_clk_gpr, hw);
> +}
> +
> +static u8 imx_clk_gpr_mux_get_parent(struct clk_hw *hw)
> +{
> +	struct imx_clk_gpr *priv = to_imx_clk_gpr(hw);
> +	unsigned int val;
> +	int ret;
> +
> +	ret = regmap_read(priv->regmap, priv->reg, &val);
> +	if (ret)
> +		goto get_parent_err;
> +
> +	val &= priv->mask;
> +
> +	ret = clk_mux_val_to_index(hw, priv->mux_table, 0, val);
> +	if (ret < 0)
> +		goto get_parent_err;
> +
> +	return ret;
> +
> +get_parent_err:
> +	pr_err("failed to get parent (%pe)\n", ERR_PTR(ret));
> +
> +	/* return some realistic non negative value. Potentially we could
> +	 * give index to some dummy error parent.
> +	 */
> +	return 0;
> +}
> +
> +static int imx_clk_gpr_mux_set_parent(struct clk_hw *hw, u8 index)
> +{
> +	struct imx_clk_gpr *priv = to_imx_clk_gpr(hw);
> +	unsigned int val = clk_mux_index_to_val(priv->mux_table, 0, index);
> +
> +	return regmap_update_bits(priv->regmap, priv->reg, priv->mask, val);
> +}
> +
> +static int imx_clk_gpr_mux_determine_rate(struct clk_hw *hw,
> +					 struct clk_rate_request *req)
> +{
> +	return clk_mux_determine_rate_flags(hw, req, 0);
> +}
> +
> +const struct clk_ops imx_clk_gpr_mux_ops = {
> +	.get_parent = imx_clk_gpr_mux_get_parent,
> +	.set_parent = imx_clk_gpr_mux_set_parent,
> +	.determine_rate = imx_clk_gpr_mux_determine_rate,
> +};
> +
> +struct clk_hw *imx_clk_gpr_mux(const char *name, const char *compatible,
> +			       u32 reg, const char **parent_names,
> +			       u8 num_parents, const u32 *mux_table, u32 mask)
> +{
> +	struct clk_init_data init  = { };
> +	struct imx_clk_gpr *priv;
> +	struct regmap *regmap;
> +	struct clk_hw *hw;
> +	int ret;
> +
> +	regmap = syscon_regmap_lookup_by_compatible(compatible);
> +	if (IS_ERR(regmap)) {
> +		pr_err("failed to find %s regmap\n", compatible);
> +		return ERR_CAST(regmap);
> +	}
> +
> +	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return ERR_PTR(-ENOMEM);
> +
> +	init.name = name;
> +	init.ops = &imx_clk_gpr_mux_ops;
> +	init.parent_names = parent_names;
> +	init.num_parents = num_parents;
> +	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
> +
> +	priv->hw.init = &init;
> +	priv->regmap = regmap;
> +	priv->mux_table = mux_table;
> +	priv->reg = reg;
> +	priv->mask = mask;
> +
> +	hw = &priv->hw;
> +	ret = clk_hw_register(NULL, &priv->hw);
> +	if (ret) {
> +		kfree(priv);
> +		hw = ERR_PTR(ret);
> +	}
> +
> +	return hw;
> +}
> diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h
> index 689b3ad927c0..801213109697 100644
> --- a/drivers/clk/imx/clk.h
> +++ b/drivers/clk/imx/clk.h
> @@ -458,4 +458,9 @@ struct clk_hw *imx_clk_hw_divider_gate(const char *name, const char *parent_name
>  		unsigned long flags, void __iomem *reg, u8 shift, u8 width,
>  		u8 clk_divider_flags, const struct clk_div_table *table,
>  		spinlock_t *lock);
> +
> +struct clk_hw *imx_clk_gpr_mux(const char *name, const char *compatible,
> +			       u32 reg, const char **parent_names,
> +			       u8 num_parents, const u32 *mux_table, u32 mask);
> +
>  #endif
> -- 
> 2.30.2
>