i.MX ProcessorsのトピックRe: How to access SPI from reboot.c file

How to access SPI from reboot.c file

lalabhaidesai — Wed, 22 Nov 2017 05:55:28 GMT

Hello,

I am using i.MX6UL and i want to access the SPI from "void kernel_power_off(void)" function before shutdown process. so please guide me that how can i access SPI from this function which is in reboot.c file. I want to send some data to my slave device using SPI from this function. I have accessed SPI from user space using spidev and it is working fine. But i could not able to access it from reboot.c file so please guide me ASAP. Thanks in advance.

Re: How to access SPI from reboot.c file

igorpadykov — Wed, 22 Nov 2017 10:43:12 GMT

Hi Lalabhai

please refer to spi ioctls described in linux/Documentation/spi/spidev

linux-imx.git - i.MX Linux Kernel

Best regards
igor
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Re: How to access SPI from reboot.c file

lalabhaidesai — Thu, 23 Nov 2017 09:53:21 GMT

Hello sir,

Thanks for your quick response, but I still not able to access SPI from reboot.c kernel file. I want to access the SPI from kernel's file "reboot.c" directly, not from user space. So what should I have to do? please guide.

Function from where I want to access SPI is shown below,

/**
* kernel_power_off - power_off the system
*
* Shutdown everything and perform a clean system power_off.
*/

void kernel_power_off(void)
{

kernel_shutdown_prepare(SYSTEM_POWER_OFF);
if (pm_power_off_prepare)
pm_power_off_prepare();
migrate_to_reboot_cpu();

syscore_shutdown();
pr_emerg("Power down");
kmsg_dump(KMSG_DUMP_POWEROFF);
machine_power_off();
}