Re: [PATCH V1 2/9] clk: sprd: Add common infrastructure

[Stephen Boyd <sboyd@codeaurora.org>]

On 06/18, Chunyan Zhang wrote:
> Added Spreadtrum's clock driver common structure and registration code.
> 
> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
> ---
>  drivers/clk/Makefile          |  1 +
>  drivers/clk/sprd/Makefile     |  3 ++
>  drivers/clk/sprd/ccu_common.c | 78 +++++++++++++++++++++++++++++++++++++
>  drivers/clk/sprd/ccu_common.h | 90 +++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 172 insertions(+)
>  create mode 100644 drivers/clk/sprd/Makefile
>  create mode 100644 drivers/clk/sprd/ccu_common.c
>  create mode 100644 drivers/clk/sprd/ccu_common.h
> 
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index c19983a..1d62721 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -81,6 +81,7 @@ obj-$(CONFIG_COMMON_CLK_SAMSUNG)	+= samsung/
>  obj-$(CONFIG_ARCH_SIRF)			+= sirf/
>  obj-$(CONFIG_ARCH_SOCFPGA)		+= socfpga/
>  obj-$(CONFIG_PLAT_SPEAR)		+= spear/
> +obj-$(CONFIG_ARCH_SPRD)			+= sprd/
>  obj-$(CONFIG_ARCH_STI)			+= st/
>  obj-$(CONFIG_ARCH_SUNXI)		+= sunxi/
>  obj-$(CONFIG_ARCH_SUNXI)		+= sunxi-ng/
> diff --git a/drivers/clk/sprd/Makefile b/drivers/clk/sprd/Makefile
> new file mode 100644
> index 0000000..8f802b2
> --- /dev/null
> +++ b/drivers/clk/sprd/Makefile
> @@ -0,0 +1,3 @@
> +ifneq ($(CONFIG_OF),)
> +obj-y	+= ccu_common.o
> +endif

I'd prefer a Kconfig for SPRD clk drivers instead of this
CONFIG_OF check. Then we can compile test the sprd code in
configurations that don't have CONFIG_ARCH_SPRD set too.

> diff --git a/drivers/clk/sprd/ccu_common.c b/drivers/clk/sprd/ccu_common.c
> new file mode 100644
> index 0000000..911f4ba
> --- /dev/null
> +++ b/drivers/clk/sprd/ccu_common.c
> @@ -0,0 +1,78 @@
> +/*
> + * Spreadtrum clock infrastructure
> + *
> + * Copyright (C) 2017 Spreadtrum, Inc.
> + *
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +
> +#include "ccu_common.h"
> +
> +static inline void __iomem *ccu_find_base(struct ccu_addr_map *maps,
> +					  unsigned int num, unsigned int reg)
> +{
> +	int i;
> +
> +	for (i = 0; i < num; i++)
> +		if ((reg & 0xffff0000) == maps[i].phy)

What is this?

> +			return maps[i].virt;
> +
> +	return 0;
> +}
> +
> +int sprd_ccu_probe(struct device_node *node, struct ccu_addr_map *maps,
> +		   unsigned int count, const struct sprd_ccu_desc *desc)
> +{
> +	int i, ret = 0;
> +	struct ccu_common *cclk;
> +	struct clk_hw *hw;
> +
> +	for (i = 0; i < desc->num_ccu_clks; i++) {
> +		cclk = desc->ccu_clks[i];
> +		if (!cclk)
> +			continue;
> +
> +		cclk->base = ccu_find_base(maps, count, cclk->reg);
> +		if (!cclk->base) {
> +			pr_err("%s: No mapped address found for clock(0x%x)\n",
> +				__func__, cclk->reg);
> +			return -EINVAL;
> +		}
> +		cclk->reg = cclk->reg & 0xffff;
> +	}
> +
> +	for (i = 0; i < desc->hw_clks->num; i++) {
> +
> +		hw = desc->hw_clks->hws[i];
> +
> +		if (!hw)
> +			continue;
> +
> +		ret = clk_hw_register(NULL, hw);
> +		if (ret) {
> +			pr_err("Couldn't register clock %d - %s\n",
> +			       i, hw->init->name);
> +			goto err_clk_unreg;
> +		}
> +	}
> +
> +	ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get,
> +				     desc->hw_clks);
> +	if (ret) {
> +		pr_err("Failed to add clock provider.\n");
> +		goto err_clk_unreg;
> +	}
> +
> +	return 0;
> +
> +err_clk_unreg:
> +	while (--i >= 0) {
> +		hw = desc->hw_clks->hws[i];
> +		if (!hw)
> +			continue;
> +
> +		clk_hw_unregister(hw);
> +	}
> +
> +	return ret;
> +}
> diff --git a/drivers/clk/sprd/ccu_common.h b/drivers/clk/sprd/ccu_common.h
> new file mode 100644
> index 0000000..ff07772
> --- /dev/null
> +++ b/drivers/clk/sprd/ccu_common.h
> @@ -0,0 +1,90 @@
> +/*
> + * Spreadtrum clock infrastructure
> + *
> + * Copyright (C) 2017 Spreadtrum, Inc.
> + *
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +
> +#ifndef _CCU_COMMON_H_
> +#define _CCU_COMMON_H_
> +
> +#include <linux/clk-provider.h>
> +
> +struct device_node;
> +
> +#define CLK_HW_INIT_NO_PARENT(_name, _ops, _flags)	\
> +	(&(struct clk_init_data) {			\
> +		.flags		= _flags,		\
> +		.name		= _name,		\
> +		.parent_names	= NULL,			\
> +		.num_parents	= 0,			\
> +		.ops		= _ops,			\
> +	})
> +
> +#define CLK_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 CLK_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,				\
> +	})
> +
> +#define CLK_FIXED_FACTOR(_struct, _name, _parent,			\
> +			_div, _mult, _flags)				\
> +	struct clk_fixed_factor _struct = {				\
> +		.div		= _div,					\
> +		.mult		= _mult,				\
> +		.hw.init	= CLK_HW_INIT(_name,			\
> +					      _parent,			\
> +					      &clk_fixed_factor_ops,	\
> +					      _flags),			\
> +	}
> +
> +struct ccu_common {
> +	void __iomem	*base;
> +	u32		reg;
> +	spinlock_t	*lock;
> +	struct clk_hw	hw;
> +};
> +
> +struct ccu_addr_map {
> +	phys_addr_t phy;
> +	void __iomem *virt;
> +};
> +
> +static inline u32 ccu_readl(struct ccu_common *common)
> +{
> +	return readl(common->base + common->reg);
> +}
> +
> +static inline void ccu_writel(u32 val, struct ccu_common *common)
> +{
> +	writel(val, common->base + common->reg);
> +}
> +
> +static inline struct ccu_common *hw_to_ccu_common(struct clk_hw *hw)
> +{
> +	return container_of(hw, struct ccu_common, hw);
> +}
> +
> +struct sprd_ccu_desc {
> +	struct ccu_common		**ccu_clks;
> +	unsigned long			num_ccu_clks;
> +	struct clk_hw_onecell_data	*hw_clks;
> +};
> +
> +int sprd_ccu_probe(struct device_node *node, struct ccu_addr_map *maps,
> +		   unsigned int count, const struct sprd_ccu_desc *desc);
> +
> +#endif /* _CCU_COMMON_H_ */

Do you call them CCUs internally? I thought CCU was a sunxi
thing, so it may make more sense to call it whatever you call the
clock controller on your hardware.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project