Re: [PATCH 5/8] ARM: zynq: add COMMON_CLK support
From: Josh Cartwright <hidden>
Date: 2012-11-02 13:40:58
Also in:
linux-arm-kernel, linux-serial, lkml
Thanks for the review. On Fri, Nov 02, 2012 at 10:33:44AM +0100, Lars-Peter Clausen wrote:
On 10/31/2012 07:58 PM, Josh Cartwright wrote:quoted
[...] +#define PERIPH_CLK_CTRL_SRC(x) (periph_clk_parent_map[((x)&3)>>4]) +#define PERIPH_CLK_CTRL_DIV(x) (((x)&0x3F00)>>8)A few more spaces wouldn't hurt ;)
Okay, sure.
quoted
[...] +static void __init zynq_periph_clk_setup(struct device_node *np) +{ + struct zynq_periph_clk *periph; + const char *parent_names[3]; + struct clk_init_data init; + struct clk *clk; + int err; + u32 reg; + int i; + + err = of_property_read_u32(np, "reg", ®); + WARN_ON(err);Shouldn't the function abort if a error happens somewhere? Continuing here will lead to undefined behavior. Same is probably true for the other WARN_ONs.
The way I see it is: the kernel is will be left in a bad state in the case of any failure, regardless of if we bail out or continue. AFAICT, there is no clean way to recover from a failure this early. Given that, it seems simpler (albeit marginally so) just to continue; so that's what I chose to do. I'm not opposed to bailing out, just not convinced it does anything for us.
quoted
+ + periph = kzalloc(sizeof(*periph), GFP_KERNEL); + WARN_ON(!periph); + + periph->clk_ctrl = slcr_base + reg; + spin_lock_init(&periph->clkact_lock); + + init.name = np->name; + init.ops = &zynq_periph_clk_ops; + for (i = 0; i < ARRAY_SIZE(parent_names); i++) + parent_names[i] = of_clk_get_parent_name(np, i); + init.parent_names = parent_names; + init.num_parents = ARRAY_SIZE(parent_names); + + periph->hw.init = &init; + + clk = clk_register(NULL, &periph->hw); + WARN_ON(IS_ERR(clk)); + + err = of_clk_add_provider(np, of_clk_src_simple_get, clk); + WARN_ON(err); + + for (i = 0; i < 2; i++) {Not all of the peripheral clock generators have two output clocks. I think it makes sense to use the number entries in clock-output-names here.
Yes, I agree. I'll also update the bindings documentation. Thanks again, Josh