On 14.01.2016 01:13, Michael Turquette wrote:
Quoting Michael Turquette (2016-01-13 12:00:12)
Hi Martin,
Quoting kernel@xxxxxxxxxxxxxxxx (2016-01-11 11:55:53)
static int bcm2835_clk_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct clk **clks;
+ size_t clk_cnt;
struct bcm2835_cprman *cprman;
struct resource *res;
+ size_t i;
+
+ /* find the max clock index */
+ clk_cnt = BCM2835_CLOCK_PERI_IMAGE; /* see below */
+ for (i = 0; i < ARRAY_SIZE(bcm2835_register_clocks); i++)
+ clk_cnt = max(clk_cnt, bcm2835_register_clocks[i].index);
+ clk_cnt += 1;
I'm not sure how this solution is better than using CLOCK_COUNT. Some
other bindings use a max value, NR_CLKS or other sentinel.
Why did you not choose to set clk_cnt equal to BCM2835_CLOCK_PWM? Why
not initialize it to zero?
OK, I just caught up on the asoc/bcm2835 thread.
Really the best solution would be to have an array of all of the clks in
the driver and just use ARRAY_SIZE on it.
For your driver, could you make an array of clk_hw pointers and call
devm_clk_register on all of them in a loop? This gets rid of the big
pile of explicit calls in bcm2835_clk_probe.
You can also get rid of stuff like bcm2835_plla_core_data by just
stuffing that data into a single struct initialization. Here is a
snippet for how the qcom clk drivers do it:
static struct clk_pll gpll0 = {
.l_reg = 0x0004,
.m_reg = 0x0008,
.n_reg = 0x000c,
.config_reg = 0x0014,
.mode_reg = 0x0000,
.status_reg = 0x001c,
.status_bit = 17,
.clkr.hw.init = &(struct clk_init_data){
.name = "gpll0",
.parent_names = (const char *[]){ "xo" },
.num_parents = 1,
.ops = &clk_pll_ops,
},
};
I did not know you could do that - that could make life easier...
But a quick look shows that this approach probably would require a
major rewrite of all the methods.
static int bcm2835_clk_probe(struct platform_device *pdev)
{
...
for (i = 0; i < num_clks; i++) {
clk = devm_clk_register(dev, array_of_clks[i].hw)
...
}
I guess I can use a slightly different approach that does not
require as many changes, that looks like this:
static const struct bcm2835_clk_desc clk_desc_array[] = {
/* register PLL */
[BCM2835_PLLA] = REGISTER_PLL(&bcm2835_plla_data),
...
};
...
static int bcm2835_clk_probe(struct platform_device *pdev)
{
const size_t asize = ARRAY_SIZE(clk_desc_array);
...
for (i = 0; i < asize; i++) {
desc = &clk_desc_array[i];
if (desc)
clks[i] = desc->clk_register(cprman,
desc->data);
}
...
}
If we need to order the initialization then we can add some
priority field to clk_desc_array and iterate over all the priority
values.
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