On 14 May 2014 08:32, Nicolas Pitre <nicolas.pitre@xxxxxxxxxx> wrote:
> On Wed, 14 May 2014, Chander Kashyap wrote:
>
>> On 14 May 2014 08:14, Abhilash Kesavan <kesavan.abhilash@xxxxxxxxx> wrote:
>> > Hi Lorenzo,
>> >
>> > On Tue, May 13, 2014 at 10:18 PM, Lorenzo Pieralisi
>> > <lorenzo.pieralisi@xxxxxxx> wrote:
>> >> On Tue, May 13, 2014 at 12:58:44PM +0100, Abhilash Kesavan wrote:
>> >>
>> >> [...]
>> >>
>> >>> +static int __init exynos_mcpm_init(void)
>> >>> +{
>> >>> + struct device_node *node;
>> >>> + int ret = 0;
>> >>
>> >> There is no point in initializing it to 0.
>> > OK.
>> >>
>> >>> +
>> >>> + node = of_find_compatible_node(NULL, NULL, "samsung,exynos5420");
>> >>> + if (!node)
>> >>> + return -ENODEV;
>> >>> + of_node_put(node);
>> >>> +
>> >>> + if (!cci_probed())
>> >>> + return -ENODEV;
>> >>> +
>> >>> + node = of_find_compatible_node(NULL, NULL,
>> >>> + "samsung,exynos4210-sysram-ns");
>> >>> + if (!node)
>> >>> + return -ENODEV;
>> >>> +
>> >>> + ns_sram_base_addr = of_iomap(node, 0);
>> >>> + of_node_put(node);
>> >>> + if (!ns_sram_base_addr) {
>> >>> + pr_err("failed to map non-secure iRAM base address\n");
>> >>> + return -ENOMEM;
>> >>> + }
>> >>> +
>> >>> + /*
>> >>> + * To increase the stability of KFC reset we need to program
>> >>> + * the PMU SPARE3 register
>> >>> + */
>> >>> + __raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
>> >>> +
>> >>> + exynos_mcpm_usage_count_init();
>> >>> +
>> >>> + ret = mcpm_platform_register(&exynos_power_ops);
>> >>> + if (!ret)
>> >>> + ret = mcpm_sync_init(exynos_pm_power_up_setup);
>> >>> + if (ret) {
>> >>> + iounmap(ns_sram_base_addr);
>> >>> + return ret;
>> >>> + }
>> >>> +
>> >>> + mcpm_smp_set_ops();
>> >>> +
>> >>> + pr_info("Exynos MCPM support installed\n");
>> >>> +
>> >>> + /*
>> >>> + * Future entries into the kernel can now go
>> >>> + * through the cluster entry vectors.
>> >>> + */
>> >>> + __raw_writel(virt_to_phys(mcpm_entry_point),
>> >>> + ns_sram_base_addr + MCPM_BOOT_ADDR_OFFSET);
>> >>> +
>> >>
>> >> ns_sram_base_addr must be unmapped, since it is unused after the write.
>> > Will unmap.
>>
>> This mapping is required in for cpuilde (suspend) to program
>> mcpm_entry before going to suspend.
>
> Why?
This is required to program the mcpm_entry point address (resume
address) after cpuidle exit/fail.
Abhilash, as i am not clearing it, it can be unmapped.
Thanks Nicolas.
>
>
> Nicolas
>
--
with warm regards,
Chander Kashyap
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