Subject: [PATCH v4 4/5] clk: hi6220: Clock driver support for Hisilicon hi6220 SoC

From: [email-masked] (Stephen Boyd)
Date: Thu, 14 May 2015 17:25:27 -0700

On 05/05, Bintian Wang wrote:
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 9897f35..935c44b 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -152,6 +152,8 @@ config COMMON_CLK_CDCE706
>  
>  source "drivers/clk/qcom/Kconfig"
>  
> +source "drivers/clk/hisilicon/Kconfig"
> +

Please move this above qcom to maintain alphabet sort.

>  endmenu
>  
>  source "drivers/clk/bcm/Kconfig"
> diff --git a/drivers/clk/hisilicon/Kconfig b/drivers/clk/hisilicon/Kconfig
> new file mode 100644
> index 0000000..8034739
> --- /dev/null
> +++ b/drivers/clk/hisilicon/Kconfig
> @@ -0,0 +1,6 @@
> +config COMMON_CLK_HI6220
> +	bool "Hi6220 Clock Driver"
> +	depends on OF && ARCH_HISI
> +	default y

Can this be

	depends on ARCH_HISI || COMPILE_TEST
	default ARCH_HISI

instead? I'd like to increase build coverage.

> +	help
> +	  Build the Hisilicon Hi6220 clock driver based on the common clock framework.
> diff --git a/drivers/clk/hisilicon/clk-hi6220.c b/drivers/clk/hisilicon/clk-hi6220.c
> new file mode 100644
> index 0000000..91b1cd7
> --- /dev/null
> +++ b/drivers/clk/hisilicon/clk-hi6220.c
> @@ -0,0 +1,292 @@
> +/*
> + * Hisilicon Hi6220 clock driver
> + *
> + * Copyright (c) 2015 Hisilicon Limited.
> + *
> + * Author: Bintian Wang <[email-masked]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/slab.h>
> +#include <linux/clk.h>

Do we need to include linux/clk.h? I don't see any consumer
usage here.

> +
> +#include <dt-bindings/clock/hi6220-clock.h>
> +
> +#include "clk.h"
> +
> diff --git a/drivers/clk/hisilicon/clk.c b/drivers/clk/hisilicon/clk.c
> index a078e84..5d2305c 100644
> --- a/drivers/clk/hisilicon/clk.c
> +++ b/drivers/clk/hisilicon/clk.c
> @@ -108,4 +123,6 @@ void __init hisi_clk_register_gate(struct hisi_gate_clock *,
>  					int, struct hisi_clock_data *);
>  void __init hisi_clk_register_gate_sep(struct hisi_gate_clock *,
>  					int, struct hisi_clock_data *);
> +void __init hi6220_clk_register_divider(struct hi6220_divider_clock *,
> +					int, struct hisi_clock_data *);

__init markings on function prototypes are useless. Please remove them.

>  #endif	/* __HISI_CLK_H */
> diff --git a/drivers/clk/hisilicon/clkdivider-hi6220.c b/drivers/clk/hisilicon/clkdivider-hi6220.c
> +
> +/**
> + * struct hi6220_clk_divider - divider clock for hi6220
> + *
> + * @hw:		handle between common and hardware-specific interfaces
> + * @reg:	register containing divider
> + * @shift:	shift to the divider bit field
> + * @width:	width of the divider bit field
> + * @mask:	mask for setting divider rate
> + * @table:	the div table that the divider supports
> + * @lock:	register lock
> + */
> +struct hi6220_clk_divider {
> +	struct clk_hw	hw;
> +	void __iomem	*reg;
> +	u8		shift;
> +	u8		width;
> +	u32		mask;
> +	const struct clk_div_table *table;
> +	spinlock_t	*lock;
> +};

The clk-divider.c code has been made "reusable". Can you please
try to use the functions that it now exposes instead of
copy/pasting it and modifying it to suit your needs? A lot of
this code looks the same.

> +
> +#define to_hi6220_clk_divider(_hw)	\
[..]
> +
> +static struct clk_ops hi6220_clkdiv_ops = {

const?

> +	.recalc_rate = hi6220_clkdiv_recalc_rate,
> +	.round_rate = hi6220_clkdiv_round_rate,
> +	.set_rate = hi6220_clkdiv_set_rate,
> +};
> +
> +struct clk *hi6220_register_clkdiv(struct device *dev, const char *name,
> +	const char *parent_name, unsigned long flags, void __iomem *reg,
> +	u8 shift, u8 width, u32 mask_bit, spinlock_t *lock)
> +{
> +	struct hi6220_clk_divider *div;
> +	struct clk *clk;
> +	struct clk_init_data init;
> +	struct clk_div_table *table;
> +	u32 max_div, min_div;
> +	int i;
> +
> +	/* allocate the divider */
> +	div = kzalloc(sizeof(struct hi6220_clk_divider), GFP_KERNEL);
> +	if (!div) {
> +		pr_err("%s: could not allocate divider clk\n", __func__);

Useless error message on allocation failure. Please run
checkpatch. I've sent a patch to remove these from basic clock
types.

> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	/* Init the divider table */
> +	max_div = div_mask(width) + 1;
> +	min_div = 1;
> +
> +	table = kzalloc(sizeof(struct clk_div_table) * (max_div + 1), GFP_KERNEL);
> +	if (!table) {
> +		kfree(div);
> +		pr_err("%s: failed to alloc divider table!\n", __func__);

ditto.

> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	for (i = 0; i < max_div; i++) {
> +		table[i].div = min_div + i;
> +		table[i].val = table[i].div - 1;
> +	}
> +
> +	init.name = name;
> +	init.ops = &hi6220_clkdiv_ops;
> +	init.flags = flags | CLK_IS_BASIC;

It's basic?

> +	init.parent_names = parent_name ? &parent_name : NULL;
> +	init.num_parents = parent_name ? 1 : 0;

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