Re: [PATCH v2 02/15] clk: sunxi-ng: Add common infrastructure

[Jean-Francois Moine <moinejf@free.fr>]

On Tue,  7 Jun 2016 22:41:41 +0200
Maxime Ripard <maxime.ripard@free-electrons.com> wrote:

> Start our new clock infrastructure by adding the registration code, common
> structure and common code.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> ---
> Changes from v1:
>   - Moved from of_iomap to of_io_request_and_map
>   - Change lock bit feature name to PLL_LOCK
>   - Fixed bug in clocks description array iteration
>   - Changed clock register offset size to u16
> ---
>  drivers/clk/Makefile              |  1 +
>  drivers/clk/sunxi-ng/Makefile     |  2 +
>  drivers/clk/sunxi-ng/ccu_common.c | 99 +++++++++++++++++++++++++++++++++++++++
>  drivers/clk/sunxi-ng/ccu_common.h | 74 +++++++++++++++++++++++++++++
>  drivers/clk/sunxi-ng/ccu_mult.h   | 15 ++++++
>  drivers/clk/sunxi-ng/ccu_reset.c  | 55 ++++++++++++++++++++++
>  drivers/clk/sunxi-ng/ccu_reset.h  | 40 ++++++++++++++++
>  7 files changed, 286 insertions(+)
>  create mode 100644 drivers/clk/sunxi-ng/Makefile
>  create mode 100644 drivers/clk/sunxi-ng/ccu_common.c
>  create mode 100644 drivers/clk/sunxi-ng/ccu_common.h
>  create mode 100644 drivers/clk/sunxi-ng/ccu_mult.h
>  create mode 100644 drivers/clk/sunxi-ng/ccu_reset.c
>  create mode 100644 drivers/clk/sunxi-ng/ccu_reset.h
> 
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index dcc5e698ff6d..7a44a1526d60 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -79,6 +79,7 @@ obj-$(CONFIG_ARCH_SOCFPGA)		+= socfpga/
>  obj-$(CONFIG_PLAT_SPEAR)		+= spear/
>  obj-$(CONFIG_ARCH_STI)			+= st/
>  obj-$(CONFIG_ARCH_SUNXI)		+= sunxi/
> +obj-$(CONFIG_ARCH_SUNXI)		+= sunxi-ng/
>  obj-$(CONFIG_ARCH_TEGRA)		+= tegra/
>  obj-y					+= ti/
>  obj-$(CONFIG_ARCH_U8500)		+= ux500/
> diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
> new file mode 100644
> index 000000000000..bd3461b0f38c
> --- /dev/null
> +++ b/drivers/clk/sunxi-ng/Makefile
> @@ -0,0 +1,2 @@
> +obj-y += ccu_common.o
> +obj-y += ccu_reset.o
> diff --git a/drivers/clk/sunxi-ng/ccu_common.c b/drivers/clk/sunxi-ng/ccu_common.c
> new file mode 100644
> index 000000000000..618fb26974c8
> --- /dev/null
> +++ b/drivers/clk/sunxi-ng/ccu_common.c
> @@ -0,0 +1,99 @@
> +/*
> + * Copyright 2016 Maxime Ripard
> + *
> + * Maxime Ripard <maxime.ripard@free-electrons.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/iopoll.h>
> +#include <linux/slab.h>
> +
> +#include "ccu_common.h"
> +#include "ccu_reset.h"
> +
> +static DEFINE_SPINLOCK(ccu_lock);
> +
> +void ccu_helper_wait_for_lock(struct ccu_common *common, u32 lock)
> +{
> +	u32 reg;
> +
> +	if (!(common->features & CCU_FEATURE_PLL_LOCK))
> +		return;

	if (!lock)
		return;

seems simpler and permits to remove the feature flag

> +
> +	WARN_ON(readl_relaxed_poll_timeout(common->base + common->reg, reg,
> +					   !(reg & lock), 100, 70000));
> +}
> +
> +int sunxi_ccu_probe(struct device_node *node, void __iomem *reg,
> +		    const struct sunxi_ccu_desc *desc)
> +{
> +	struct ccu_common **cclks = desc->clks;
> +	size_t num_clks = desc->num_clks;
> +	struct clk_onecell_data *data;
> +	struct ccu_reset *reset;
> +	struct clk **clks;
> +	int i, ret;
> +
> +	data = kzalloc(sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	clks = kcalloc(num_clks, sizeof(struct clk *), GFP_KERNEL);
> +	if (!clks)
> +		return -ENOMEM;
> +
> +	data->clks = clks;
> +	data->clk_num = num_clks;
> +
> +	for (i = 0; i < num_clks; i++) {
> +		struct ccu_common *cclk = cclks[i];
> +		struct clk *clk;
> +
> +		if (!cclk) {
> +			clks[i] = ERR_PTR(-ENOENT);
> +			continue;
> +		}
> +
> +		cclk->base = reg;
> +		cclk->lock = &ccu_lock;
> +
> +		clk = clk_register(NULL, &cclk->hw);
> +		if (IS_ERR(clk))
> +			continue;

On error, clks[i] is not initialized. I would better see:

		if (IS_ERR(clk))
			pr_err("Clock %d err %d\n", i, (int) PTR_ERR(clk));

> +
> +		clks[i] = clk;
> +	}
> +
> +	ret = of_clk_add_provider(node, of_clk_src_onecell_get, data);
> +	if (ret)
> +		goto err_clk_unreg;
> +
> +	reset = kzalloc(sizeof(*reset), GFP_KERNEL);
> +	reset->rcdev.of_node = node;
> +	reset->rcdev.ops = &ccu_reset_ops;
> +	reset->rcdev.owner = THIS_MODULE;
> +	reset->rcdev.nr_resets = desc->num_resets;
> +	reset->base = reg;
> +	reset->lock = &ccu_lock;
> +	reset->reset_map = desc->resets;
> +
> +	ret = reset_controller_register(&reset->rcdev);
> +	if (ret)
> +		goto err_of_clk_unreg;
> +
> +	return 0;
> +
> +err_of_clk_unreg:
> +err_clk_unreg:
> +	return ret;
> +}
> diff --git a/drivers/clk/sunxi-ng/ccu_common.h b/drivers/clk/sunxi-ng/ccu_common.h
> new file mode 100644
> index 000000000000..fda245020273
> --- /dev/null
> +++ b/drivers/clk/sunxi-ng/ccu_common.h
> @@ -0,0 +1,74 @@
> +/*
> + * Copyright (c) 2016 Maxime Ripard. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _COMMON_H_
> +#define _COMMON_H_
> +
> +#include <linux/compiler.h>
> +#include <linux/clk-provider.h>
> +
> +#define CCU_FEATURE_GATE		BIT(0)
> +#define CCU_FEATURE_PLL_LOCK		BIT(1)
> +#define CCU_FEATURE_FRACTIONAL		BIT(2)
> +#define CCU_FEATURE_VARIABLE_PREDIV	BIT(3)
> +#define CCU_FEATURE_FIXED_PREDIV	BIT(4)
> +#define CCU_FEATURE_FIXED_POSTDIV	BIT(5)
> +
> +struct device_node;
> +
> +#define SUNXI_HW_INIT(_name, _parent, _ops, _flags)			\
> +	&(struct clk_init_data) {					\
> +		.flags		= _flags,				\
> +		.name		= _name,				\
> +		.parent_names	= (const char *[]) { _parent },		\
> +		.num_parents	= 1,					\
> +		.ops 		= _ops,					\
> +	}
> +
> +#define SUNXI_HW_INIT_PARENTS(_name, _parents, _ops, _flags)		\
> +	&(struct clk_init_data) {					\
> +		.flags		= _flags,				\
> +		.name		= _name,				\
> +		.parent_names	= _parents,				\
> +		.num_parents	= ARRAY_SIZE(_parents),			\
> +		.ops 		= _ops,					\
> +	}
> +
> +struct ccu_common {
> +	void __iomem	*base;
> +	u16		reg;
> +
> +	unsigned long	features;

u16 should be enough for now

> +	spinlock_t	*lock;
> +	struct clk_hw	hw;
> +};
> +
> +static inline struct ccu_common *hw_to_ccu_common(struct clk_hw *hw)
	[snip]

-- 
Ken ar c'hentañ	|	      ** Breizh ha Linux atav! **
Jef		|		http://moinejf.free.fr/