[PATCH v6 5/5] arm: exynos: Add MCPM call-back functions

[Nicolas Pitre]

On Wed, 14 May 2014, Chander Kashyap wrote:

> On 14 May 2014 08:14, Abhilash Kesavan <kesavan.abhilash at gmail.com> wrote:
> > Hi Lorenzo,
> >
> > On Tue, May 13, 2014 at 10:18 PM, Lorenzo Pieralisi
> > <lorenzo.pieralisi at arm.com> 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?


Nicolas