Subject: [PATCHv9 13/43] clk: ti: add support for basic mux clock

From: [email-masked] (Nishanth Menon)
Date: Fri, 1 Nov 2013 16:01:15 -0500

On 10/25/2013 10:57 AM, Tero Kristo wrote:
[...]
> diff --git a/drivers/clk/ti/mux.c b/drivers/clk/ti/mux.c
> new file mode 100644
> index 0000000..9c5259a
> --- /dev/null
> +++ b/drivers/clk/ti/mux.c
[...]
> +/**
> + * of_mux_clk_setup() - Setup function for simple mux rate clock
> + */
> +static int of_mux_clk_setup(struct device_node *node, struct regmap *regmap)

$ ./scripts/kernel-doc drivers/clk/ti/mux.c >/dev/null
Warning(drivers/clk/ti/mux.c:29): No description found for parameter
'node'
Warning(drivers/clk/ti/mux.c:29): No description found for parameter
'regmap'

I suggest in the next rev we do a verification if we have kernel doc
errors as well..

> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	void __iomem *reg;
> +	int num_parents;
> +	const char **parent_names;
> +	int i;
> +	u8 clk_mux_flags = 0;
> +	u32 mask = 0;
> +	u32 shift = 0;
> +	u32 flags = 0;
> +	u32 val;
> +
> +	num_parents = of_clk_get_parent_count(node);
> +	if (num_parents < 1) {
> +		pr_err("%s: mux-clock %s must have parent(s)\n",
> +		       __func__, node->name);
> +		return -EINVAL;
> +	}
> +	parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL);
> +	if (!parent_names) {
> +		pr_err("%s: memory alloc failed\n", __func__);

as discussed, could be dropped.

> +		return -ENOMEM;
> +	}
> +
> +	for (i = 0; i < num_parents; i++)
> +		parent_names[i] = of_clk_get_parent_name(node, i);
> +
> +	of_property_read_u32(node, "reg", &val);

is'nt this mandatory? error check?

> +	reg = (void *)val;
> +
> +	if (of_property_read_u32(node, "ti,bit-shift", &shift)) {
> +		pr_debug("%s: bit-shift property defaults to 0x%x for %s\n",
> +			 __func__, shift, node->name);

why a debug if this is optional?

> +	}
> +
> +	if (of_property_read_bool(node, "ti,index-starts-at-one"))
> +		clk_mux_flags |= CLK_MUX_INDEX_ONE;
> +
> +	if (of_property_read_bool(node, "ti,set-rate-parent"))
> +		flags |= CLK_SET_RATE_PARENT;
> +
> +	/* Generate bit-mask based on parent info */
> +	mask = num_parents;
> +	if (!(clk_mux_flags & CLK_MUX_INDEX_ONE))
> +		mask--;

we are assuming there wont be holes in the map (like reserved mux option?)

> +
> +	mask = (1 << fls(mask)) - 1;
> +
> +	clk = clk_register_mux_table_regmap(NULL, clk_name, parent_names,
> +					    num_parents, flags, reg, regmap,
> +					    shift, mask, clk_mux_flags, NULL,
> +					    NULL);
> +
> +	if (!IS_ERR(clk)) {
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +		return 0;
> +	}
> +

kfree(parent_names)?

> +	return PTR_ERR(clk);
> +}
> +CLK_OF_DECLARE(mux_clk, "ti,mux-clock", of_mux_clk_setup);
> +
> +static int __init of_ti_composite_mux_clk_setup(struct device_node *node,
> +						struct regmap *regmap)
> +{
> +	struct clk_mux *mux;
> +	int num_parents;
> +	int ret;
> +	u32 val;
> +
> +	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
> +	if (!mux)
> +		return -ENOMEM;
> +
> +	of_property_read_u32(node, "reg", &val);
is'nt this mandatory? error check?

> +
> +	mux->reg = (void *)val;
> +	mux->regmap = regmap;
> +
> +	if (of_property_read_u32(node, "ti,bit-shift", &val)) {
> +		pr_debug("%s: no bit-shift for %s, default=0\n",
> +			 __func__, node->name);
> +		val = 0;
> +	}
> +	mux->shift = val;
> +
> +	num_parents = of_clk_get_parent_count(node);

mandatory parameter without check?

ti,index-starts-at-one, ti,set-rate-parent
these seem not supported here even though the bindings dont tell us that.

> +
> +	mux->mask = num_parents - 1;
> +	mux->mask = (1 << fls(mux->mask)) - 1;
> +
> +	ret = ti_clk_add_component(node, &mux->hw, CLK_COMPONENT_TYPE_MUX);
> +	if (!ret)
> +		return 0;
> +
> +	kfree(mux);
> +	return -ret;
> +}
> +CLK_OF_DECLARE(ti_composite_mux_clk_setup, "ti,composite-mux-clock",
> +	       of_ti_composite_mux_clk_setup);
> 

-- 
Regards,
Nishanth Menon