Hi Rahul,
On 03/08/2014 04:20 AM, Rahul Sharma wrote:
Hi Tomasz,
On 7 March 2014 20:52, Tomasz Figa <tomasz.figa@xxxxxxxxx> wrote:
On 07.03.2014 16:10, Pankaj Dubey wrote:
Hi Tomasz,
On Fri, Mar 7, 2014 at 11:12 PM, Tomasz Figa <tomasz.figa@xxxxxxxxx>
wrote:
Hi Pankaj,
On 07.03.2014 14:56, Pankaj Dubey wrote:
+static void __init exynos5260_clk_top_init(struct device_node *np)
+{
+ struct exynos5260_cmu_info cmu;
+ struct samsung_clk_provider *ctx;
+
+ memset(&cmu, 0, sizeof(cmu));
+
+ cmu.pll_clks = top_pll_clks;
+ cmu.nr_pll_clks = ARRAY_SIZE(top_pll_clks);
+ cmu.mux_clks = top_mux_clks;
+ cmu.nr_mux_clks = ARRAY_SIZE(top_mux_clks);
+ cmu.div_clks = top_div_clks;
+ cmu.nr_div_clks = ARRAY_SIZE(top_div_clks);
+ cmu.gate_clks = top_gate_clks;
+ cmu.nr_gate_clks = ARRAY_SIZE(top_gate_clks);
+ cmu.nr_clk_ids = TOP_NR_CLK;
+ cmu.clk_regs = top_clk_regs;
+ cmu.nr_clk_regs = ARRAY_SIZE(top_clk_regs);
+
+ ctx = exynos5260_cmu_register_one(np, &cmu);
+
+ samsung_clk_of_register_fixed_ext(ctx, fixed_rate_ext_clks,
+ ARRAY_SIZE(fixed_rate_ext_clks),
+ ext_clk_match);
+}
+
+CLK_OF_DECLARE(exynos5260_clk_top, "samsung,exynos5260-clock-top",
+ exynos5260_clk_top_init);
Well with this approach we end up adding 14 such
exynosxxx_clk_xxx_init functions all of which has similar lines of
code. As I know there are many upcoming Exynos SoC which will also
have similar multiple clock controllers (in some of them there are
upto 25 clock domains, and in that case we will end up writing 25 such
init functions) so I have following suggestion where we can have one
more structure which will hold all static data and match_table to
match compatibility string and return CMU_TYPE which can be mapped to
get proper clock_data which can be used in single clock_init function.
Following is some sample code which I have implemented and tested on
one of Exynos SoC. Please let me know your opinion about this.
Yes, this looks better indeed, however there is still a room for
improvement. Please see my comments below.
=============================
static struct exynosxxxx_clock_data exynosxxxx_clk_data[] __initdata = {
Instead of making this an array, particular elements could be separate
structures. This would simplify the code below.
{
.cmu_type = CMU_TYPE_TOP,
.mux_clocks = top_mux_clks,
.div_clocks = top_div_clks,
.pll_clocks = top_pll_clks,
.clk_regs = top_clk_regs,
.nr_mux_clocks = ARRAY_SIZE(top_mux_clks),
.nr_div_clocks = ARRAY_SIZE(top_div_clks),
.nr_pll_clocks = ARRAY_SIZE(top_pll_clks),
.nr_clk_regs = ARRAY_SIZE(top_clk_regs),
.nr_clks = TOP_NR_CLK,
}, {
.cmu_type = CMU_TYPE_EGL,
.mux_clocks = egl_mux_clks,
.div_clocks = egl_div_clks,
.pll_clocks = egl_pll_clks,
.clk_regs = egl_clk_regs,
.nr_mux_clocks = ARRAY_SIZE(egl_mux_clks),
.nr_div_clocks = ARRAY_SIZE(egl_div_clks),
.nr_pll_clocks = ARRAY_SIZE(egl_pll_clks),
.nr_clk_regs = ARRAY_SIZE(egl_clk_regs),
.nr_clks = EGL_NR_CLK,
}, {
/* Add similar elements here */
};
static struct of_device_id cmu_subtype_match_table[] = {
{
.compatible = "exynosxxxx-cmu-top",
.data = (void *)CMU_TYPE_TOP,
Here the data would be just a pointer to respective clock data struct
defined above.
}, {
.compatible = "exynosxxx-cmu-peris",
.data = (void *)CMU_TYPE_PERIS,
}, {
/* Add similar elements here */
};
void __init exynosxxx_clk_init(struct device_node *np)
{
[snip]
match = of_match_node(cmu_subtype_match_table, np);
if (!match)
panic("%s: cmu type (%s) is not supported.\n",
__func__,
np->name);
This can't happen, because this function won't be called for any node
with
compatible string not declared using CLK_OF_DECLARE().
Agreed.
reg_base = of_iomap(np, 0);
if (!reg_base)
panic("%s: failed to map registers\n", __func__);
cmu_type = (unsigned long) match->data;
for (; i < CMU_TYPE_ALL; i++) {
clk_data = &exynosxxxx_clk_data[i];
if (cmu_type == clk_data->cmu_type)
break;
}
Now clk_data could be taken directly from match->data, without the need
to
iterate over an array.
I am just curious, is it really a worth to replace 14 init functions
with 14 same
sized isolated structures. We will also be adding a array of these structure
pointers and little overhead to parse this array based on compatible
string for each cmu probe.
IMHO, calling correct function meant for the given CMU, looks more
straight and crisp. Most of the duplication is already addressed in
exynos5260_cmu_register_one.
Please, let me know if we are still looking for this change. It should
be easy to
change it that way.
Good point. Let me change as per your suggestion and test. And then we
will go for this change in next new version of patch.
OK, thanks.
Also please
review rest patch also and let us know if anything still can be
improved.
I had reviewed version 3 of this series and most of my comments have been
addressed. I'm waiting for remaining two to be addressed, but they are
covered by your comments for v4.
I will address the fixes for fin_pll and sclk_uart in the next
version. Thanks for the
review.
One update from my end.
Today I verified that even though I removed CLK_IGNORE_UNUSED flag from
sclk_uartX I can
see kernel is booting fine and no issues as you mentioned. FYI I am
using 3.14_rc1 tag and
applied all patches on top of it. For reference I have mailed all
related patches to you.
@Tomasz,
I modified code as per our discussion and addressed all comments
including moving fixed clock to DT
and found it's working well, so we can now finalize which way to go ahead.
Following is some data between V4 and probable next version, which might
help in making decision.
drivers/clk/samsung/exynos5260-clock.c
Before Change
LoC: 1890
size drivers/clk/samsung/clk-exynos5260.o
text data bss dec hex filename
14226 14956 0 29182 71fe
drivers/clk/samsung/clk-exynos5260.o
After Change:
LoC: 1806
size drivers/clk/samsung/clk-exynos5260.o
text data bss dec hex filename
15446 14544 0 29990 7526
drivers/clk/samsung/clk-exynos5260.o
Regards,
Rahul Sharma.
A link to v3 thread for reference:
http://thread.gmane.org/gmane.linux.kernel.samsung-soc/27249
Best regards,
Tomasz
--
Best Regards,
Pankaj Dubey
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