Hi Marek/Jingoo,
On Wed, Jun 22, 2011 at 3:17 PM, Marek Szyprowski
<[email protected]> wrote:
> Hello,
>
> On Wednesday, June 22, 2011 8:42 AM Jingoo Han wrote:
>
>> From: Jonghun Han <[email protected]>
(snipped)
Instead of hardcoding the parent clock in platform/bootloader code ,is
it not possible to select/set the
parent clock based on the pixel clk(plat data) having the least delta
with the 9 src clks.with this change I have checked it for WA101S.
These are the changes I am proposing..
arch/arm/mach-exynos4/clock.c
+struct clk *clkset_sclk_fimd0_list[] = {
+ [0] = &clk_sclk_xxti,
+ [1] = &clk_sclk_xusbxti,
+ [2] = &clk_sclk_hdmi27m,
+ [3] = &clk_sclk_usbphy0,
+ [4] = &clk_sclk_usbphy1,
+ [5] = &clk_sclk_hdmiphy,
+ [6] = &clk_mout_mpll.clk,
+ [7] = &clk_mout_epll.clk,
+ [8] = &clk_sclk_vpll.clk,
+};
arch/arm/mach-exynos4/mach-smdkv310.c
+static int fimd_s3c_consider_clock(struct device *sfb,int src
,unsigned int wanted)
+{
+ unsigned long rate = 0;
+ int div =1;
+ struct clk *mout_mpll = NULL;
+
+ if(clkset_sclk_fimd0_list[src]){
+ mout_mpll = clk_get(sfb,clkset_sclk_fimd0_list[src]->name);
+ if (IS_ERR(mout_mpll)) {
+ dev_err(sfb, "failed to clk_get
%s\n",clkset_sclk_fimd0_list[src]->name);
+ }
+
+ rate = clk_get_rate(mout_mpll);
+
+ for (div = 1; div < 256; div *= 2) {
+ if ((rate / div) <= wanted)
+ break;
+ }
+
+
+ }
+ return (wanted - (rate / div));
+}
+
+int exynos4_fimd0_find_clock(struct platform_device *pdev,struct clk
**lcd_clk,unsigned int clock(pixel clock needed for the lcd))
+{
+ int best = 0;
+ int delta = 0;
+ int best_src = 0;
+ int src;
+ struct clk *best_clk_src = NULL;
+ struct clk *clk = NULL;
+
+ if (clock == 0)
+ return 0;
+
+ for (src = 0; src < MAX_NUM_CLKS ;src++) {
+ delta = fimd_s3c_consider_clock(&pdev->dev,src,clock);
+ if (delta < best) {
+ best = delta;
+ best_src = src;
+ }
+ }
+ clk = clk_get(&pdev->dev, "sclk_fimd");
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "failed to get sclk for fimd\n");
+ goto err_clk2;
+ }
+
+ best_clk_src =
clk_get(&pdev->dev,clkset_sclk_fimd0_list[best_src]->name);
+ if (IS_ERR(best_clk_src)) {
+ dev_err(&pdev->dev, "failed to get best_src\n");
+ goto err_clk1;
+ }
+ clk_set_parent(clk,best_clk_src);
+ *lcd_clk = clk;
+ clk_put(best_clk_src);
+ clk_enable(clk);
+ dev_dbg(&pdev->dev, "set fimd sclk rate to %d\n", clock);
+
+err_clk1:
+ clk_put(best_clk_src);
+err_clk2:
+ clk_put(clk);
+
+ return -EINVAL;
+}
I have based these patches on the v1 version of this patch.I can base
these changes
on your latest changes(v6) and send as a patch.
>> +static int __init smdkc210_fimd0_setup_clock(void)
>> +{
>> + struct clk *sclk = NULL;
>> + struct clk *mout_mpll = NULL;
>> +
>> + u32 rate = 0;
>> +
>> + sclk = clk_get(&s5p_device_fimd0.dev, "sclk_fimd");
>> + if (IS_ERR(sclk)) {
>> + printk(KERN_ERR "failed to get sclk for fimd\n");
>> + goto err_clk2;
>> + }
>> +
>> + mout_mpll = clk_get(NULL, "mout_mpll");
>> + if (IS_ERR(mout_mpll)) {
>> + printk(KERN_ERR "failed to get mout_mpll\n");
>> + goto err_clk1;
>> + }
>> +
>> + clk_set_parent(sclk, mout_mpll);
>> + if (!rate)
>> + rate = 134000000;
>> +
>> + clk_set_rate(sclk, rate);
>> +
>> + clk_put(sclk);
>> + clk_put(mout_mpll);
>> +
>> + return 0;
>> +
>> +err_clk1:
>> + clk_put(mout_mpll);
>> +err_clk2:
>> + clk_put(sclk);
>> +
>> + return -EINVAL;
>> +}
>> +
>
> I'm not sure if mach-smdk*.c is the right place for the above code.
> IMHO all the code that configures very low level, board specific parameters
> (like clocks and their relations) should be performed in boot loarder.
>
I feel pushing the clock enabling into the bootloader,will create an
unneccesary dependcy for the lcd on the u-boot.
> (snipped)
>
> Best regards
> --
> Marek Szyprowski
> Samsung Poland R&D Center
>
>
>
regards
anand
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