Messages in this thread | | | Date | Sat, 23 May 2015 21:30:27 +0200 | From | Sergej Sawazki <> | Subject | Re: [PATCH RFC v1] clk: add gpio controlled clock multiplexer |
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Stephen, thanks for the review...
On 21.05.2015 at 21:31 Stephen Boyd wrote: >> +static int clk_gpio_mux_set_parent(struct clk_hw *hw, u8 index) >> +{ >> + struct clk_gpio_mux *clk = to_clk_gpio_mux(hw); >> + >> + if (index > 1) >> + return -EINVAL; > > Doesn't seem possible if num_parents is correct. Please drop. >
Right, thanks.
>> + if (err) { >> + pr_err("%s: %s: Error requesting gpio %u\n", >> + __func__, name, desc_to_gpio(gpiod_sel)); > > What if the error is probe defer? We should be silent in such a > situation. I see this is mostly copy/paste from gpio-gate.c so > perhaps we should fix that one too. >
Agreed.
>> + return ERR_PTR(err); >> + } >> + clk_gpio_mux->gpiod_sel = gpiod_sel; >> + >> + if (gpiod_ena != NULL) { > > Style nitpick: > > if (gpiod_ena) { > > is preferred. >
Agreed.
>> + return ERR_PTR(err); >> + } >> + clk_gpio_mux->gpiod_ena = gpiod_ena; >> + } >> + >> + init.name = name; >> + init.ops = &clk_gpio_mux_ops; >> + init.flags = clk_flags | CLK_IS_BASIC; >> + init.parent_names = parent_names; >> + init.num_parents = num_parents; > > Should we make sure num_parents is 2? >
You are probably right.
>> + >> + clk_gpio_mux->hw.init = &init; >> + >> + clk = clk_register(dev, &clk_gpio_mux->hw); > > But no if (dev) devm_*() trick here? >
Oh, right.
>> + >> + if (!IS_ERR(clk)) >> + return clk; >> + >> + if (!dev) { >> + kfree(clk_gpio_mux); >> + gpiod_put(gpiod_ena); > > Isn't gpiod_ena optional? And so calling gpiod_put() here might > cause a warning? >
Oops, right.
> Actually I wonder why we wouldn't just make this a gpio-mux > without enable/disable support? If we want to do enable/disable, > we can parent the gpio gate to this mux. Alternatively, we could > combine the gpio-gate file and this new mux file into one file > and support both compatible strings. There's quite a bit of > duplicated code so this may be a better approach. >
I agree, I am going to remove the enable/disable support.
>> +static struct clk *of_clk_gpio_mux_delayed_register_get( >> + struct of_phandle_args *clkspec, >> + void *_data) >> +{ >> + struct clk_gpio_mux_delayed_register_data *data = _data; >> + struct clk *clk = ERR_PTR(-EINVAL); >> + const char *clk_name = data->node->name; >> + int i, num_parents; >> + const char **parent_names; >> + struct gpio_desc *gpiod_sel, *gpiod_ena; >> + int gpio; >> + u32 flags = 0; > > This is only used on place and never assigned otherwise, why not > just use 0 in place of flags? >
Well, you are probably right, I thought it is better to define it here, than to use a magic number in clk_register_gpio_mux().
>> + >> + num_parents = of_clk_get_parent_count(data->node); >> + if (num_parents < 2) { > > Should that be num_parents != 2? >
Oops, right.
>> + pr_err("mux-clock %s must have 2 parents\n", data->node->name); >> + return clk; >> + } >> + >> + parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL); > > kcalloc() please. >
OK.
>> +err_gpio: >> + mutex_unlock(&data->lock); >> + if (gpio == -EPROBE_DEFER) >> + pr_warn("%s: %s: GPIOs not yet available, retry later\n", >> + __func__, clk_name); > > pr_debug >
OK.
>> + else >> + pr_err("%s: %s: Can't get GPIOs\n", >> + __func__, clk_name); >> + return ERR_PTR(gpio); >> +} >> + >> +/** >> + * of_gpio_mux_clk_setup() - Setup function for gpio controlled clock mux >> + */ >> +void __init of_gpio_mux_clk_setup(struct device_node *node) >> +{ >> + struct clk_gpio_mux_delayed_register_data *data; >> + >> + data = kzalloc(sizeof(struct clk_gpio_mux_delayed_register_data), > > please use kzalloc(sizeof(*data), GFP_KERNEL); style >
OK.
Best regards, Sergej
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