On Sunday, April 13, 2014 at 09:55:57 PM, Ian Campbell wrote:
On Mon, 2014-03-24 at 23:42 +0100, Olliver Schinagl wrote:
On 03/24/2014 09:52 PM, Marek Vasut wrote:
- /* Switch to 24MHz clock while changing PLL1 */
- writel(AXI_DIV_1 << AXI_DIV_SHIFT |
AHB_DIV_2 << AHB_DIV_SHIFT |APB0_DIV_1 << APB0_DIV_SHIFT |CPU_CLK_SRC_OSC24M << CPU_CLK_SRC_SHIFT,&ccm->cpu_ahb_apb0_cfg);- sdelay(20);
What is sdelay() function all about ?
It also is from arch/arm/include/asm/arch-sunxi/sys_proto.h and I thought all where replaced with udelays
Since these sdelays() are used while we are frobbing around with the clocks I'm not sure that switching to udelay is possible/wise. sdelay is documented as:
- sdelay() - simple spin loop. Will be constant time as
- its generally used in bypass conditions only. This
- is necessary until timers are accessible.
IOW it sounds like it is designed to be used in exactly these circumstances.
Given the lack of documentation for what is actually required by the hardware when changing these clocks I'm a bit reluctant to go changing things.
Don't you have an clock-agnostic timer in the chip ? If not, well, can't be helped.
Best regards, Marek Vasut