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    SubjectRe: [PATCH v2 7/7] ACPI: import watchdog info of GTDT into platform device
    +CC Catalin and Will

    On 2015年05月21日 16:32, fu.wei@linaro.org wrote:
    > From: Fu Wei <fu.wei@linaro.org>
    >
    > Parse SBSA Generic Watchdog Structure in GTDT table of ACPI,
    > and create a platform device with that information.
    > This platform device can be used by the ARM SBSA Generic
    > Watchdog driver.
    >
    > Signed-off-by: Fu Wei <fu.wei@linaro.org>
    > ---
    > arch/arm64/kernel/acpi.c | 136 +++++++++++++++++++++++++++++++++++++++++++++++
    > 1 file changed, 136 insertions(+)
    >
    > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
    > index 8b83955..1ed11fd 100644
    > --- a/arch/arm64/kernel/acpi.c
    > +++ b/arch/arm64/kernel/acpi.c
    > @@ -23,6 +23,7 @@
    > #include <linux/irqdomain.h>
    > #include <linux/memblock.h>
    > #include <linux/of_fdt.h>
    > +#include <linux/platform_device.h>
    > #include <linux/smp.h>
    >
    > #include <asm/cputype.h>
    > @@ -343,3 +344,138 @@ void __init acpi_gic_init(void)
    >
    > early_acpi_os_unmap_memory((char *)table, tbl_size);
    > }
    > +
    > +static int __init acpi_gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
    > + int index)
    > +{
    > + struct platform_device *pdev;
    > + struct resource *res;
    > + u32 gsi, flags;
    > + int irq, trigger, polarity;
    > + resource_size_t rf_base_phy, cf_base_phy;
    > + int err = -ENOMEM;
    > +
    > + /*
    > + * Get SBSA Generic Watchdog info
    > + * from a Watchdog GT type structure in GTDT
    > + */
    > + rf_base_phy = (resource_size_t)wd->refresh_frame_address;
    > + cf_base_phy = (resource_size_t)wd->control_frame_address;
    > + gsi = wd->timer_interrupt;
    > + flags = wd->timer_flags;
    > +
    > + pr_info("GTDT: a Watchdog GT structure(0x%llx/0x%llx gsi:%u flags:0x%x)\n",
    > + rf_base_phy, cf_base_phy, gsi, flags);

    Can we use pr_debug here? I don't think those information
    worthy a pr_info.

    > +
    > + if (!(rf_base_phy && cf_base_phy && gsi)) {
    > + pr_err("GTDT: failed geting the device info.\n");
    > + return -EINVAL;
    > + }
    > +
    > + trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
    > + : ACPI_LEVEL_SENSITIVE;
    > + polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
    > + : ACPI_ACTIVE_HIGH;

    I see places to duplicate this, I will look into this to see we can form
    a function to handle it.

    > + irq = acpi_register_gsi(NULL, gsi, trigger, polarity);
    > + if (irq < 0) {
    > + pr_err("GTDT: failed to register GSI of the Watchdog GT.\n");
    > + return -EINVAL;
    > + }
    > +
    > + pdev = platform_device_alloc("sbsa-gwdt", index);

    Please put a comment before this function to explain
    why we need a "sbsa-gwdt" name here.

    > + if (!pdev)
    > + goto err_unregister_gsi;
    > +
    > + res = kcalloc(3, sizeof(*res), GFP_KERNEL);
    > + if (!res)
    > + goto err_device_put;
    > +
    > + res[0].start = rf_base_phy;
    > + res[0].end = rf_base_phy + SZ_4K - 1;
    > + res[0].name = "refresh";
    > + res[0].flags = IORESOURCE_MEM;
    > +
    > + res[1].start = cf_base_phy;
    > + res[1].end = cf_base_phy + SZ_4K - 1;

    So why SZ_4K? is it defined in SBSA spec? if so, please
    comment on it too.

    > + res[1].name = "control";
    > + res[1].flags = IORESOURCE_MEM;
    > +
    > + res[2].start = irq;
    > + res[2].end = res[2].start;
    > + res[2].name = "ws0";
    > + res[2].flags = IORESOURCE_IRQ;
    > +
    > + err = platform_device_add_resources(pdev, res, 3);
    > + if (err)
    > + goto err_free_res;
    > +
    > + err = platform_device_add(pdev);
    > + if (err)
    > + goto err_free_res;
    > +
    > + return 0;
    > +
    > +err_free_res:
    > + kfree(res);
    > +err_device_put:
    > + platform_device_put(pdev);
    > +err_unregister_gsi:
    > + acpi_unregister_gsi(gsi);
    > +
    > + return err;
    > +}
    > +
    > +/* Initialize SBSA generic Watchdog platform device info from GTDT */
    > +static int __init acpi_gtdt_sbsa_gwdt_init(struct acpi_table_header *table)
    > +{
    > + struct acpi_table_gtdt *gtdt;
    > + struct acpi_gtdt_header *header;
    > + void *gtdt_subtable;
    > + int i, gwdt_index;
    > + int ret = 0;
    > +
    > + if (table->revision < 2) {
    > + pr_info("GTDT: Revision:%d doesn't support Platform Timers.\n",
    > + table->revision);

    pr_warn() would be good.

    Thanks
    Hanjun


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