Re: [PATCH v2] MIPS: Loongson64: Add Loongson-2K1000 reset support

[zhangqing <zhangqing@xxxxxxxxxxx>]

On 06/28/2021 09:12 AM, Jiaxun Yang wrote:
> 在 2021/6/27 下午3:38, Qing Zhang 写道:
> > Add power management register operations to support reboot and poweroff.
> >
> > Signed-off-by: Qing Zhang <zhangqing@xxxxxxxxxxx>
> > ---
> >
> > v1-v2:
> > - Add pm block node
> >
> > Signed-off-by: Qing Zhang <zhangqing@xxxxxxxxxxx>
> >
> > diff --git a/arch/mips/boot/dts/loongson/loongson64-2k1000.dtsi 
> > b/arch/mips/boot/dts/loongson/loongson64-2k1000.dtsi
> > index 569e814def83..929e8ddf86eb 100644
> > --- a/arch/mips/boot/dts/loongson/loongson64-2k1000.dtsi
> > +++ b/arch/mips/boot/dts/loongson/loongson64-2k1000.dtsi
> > @@ -101,6 +101,14 @@ uart0: serial@1fe00000 {
> >               no-loopback-test;
> >           };
> >   +        pm: power-controller {
> > +            device_type = "power management";
>
> Hi Qing,
>
> Not compatible?
>
>
> > +            reg = <0 0x1fe0700c 0 0x8>,
> > +                <0 0x1fe07014 0 0x8>,
> > +                <0 0x1fe07030 0 0x8>;
> > +            reg-names = "pm1_sts", "pm1_cnt", "rst_cnt";
> > +        };
> > +
> >           pci@1a000000 {
> >               compatible = "loongson,ls2k-pci";
> >               device_type = "pci";
> > diff --git a/arch/mips/loongson64/reset.c b/arch/mips/loongson64/reset.c
> > index c97bfdc8c922..ea125e925d44 100644
> > --- a/arch/mips/loongson64/reset.c
> > +++ b/arch/mips/loongson64/reset.c
> > @@ -10,6 +10,7 @@
> >   #include <linux/delay.h>
> >   #include <linux/init.h>
> >   #include <linux/kexec.h>
> > +#include <linux/of_address.h>
> >   #include <linux/pm.h>
> >   #include <linux/slab.h>
> >   @@ -20,12 +21,50 @@
> >   #include <loongson.h>
> >   #include <boot_param.h>
> >   +static char *pm_reg_name[] = {"pm1_sts", "pm1_cnt", "rst_cnt"};
> > +
> > +static void __iomem *get_reg_byname(struct device_node *node, const 
> > char *name)
> > +{
> > +    int index = of_property_match_string(node, "reg-names", name);
> > +
> > +    if (index < 0)
> > +        return NULL;
> > +
> > +    return of_iomap(node, index);
> > +}
>
> We do have that helper in of_address.h.
>
> Btw, I'd prefer make it as a driver in driver/platform/mips.
>
> Also the approach using PRID to tell protocol type doesn't really make 
> sense to me.
>
> You can override _machine_restart callback in diver once FDT node is 
> found.

Hi jiaxun,

Thanks for your suggestion,
I will send v3 in the soon.

Thanks.,

Qing
> Thanks.
>
> - Jiaxun
>
> > +
> > +static int  __init loongson_fdt_reset_init(void)
> > +{
> > +    struct device_node *np;
> > +    int i;
> > +
> > +    np = of_find_node_by_type(NULL, "power management");
> > +    if (!np) {
> > +        pr_info("Failed to get PM node\n");
> > +        return -ENODEV;
> > +    }
> > +
> > +    for (i = 0; i < sizeof(pm_reg_name)/sizeof(char *); i++) {
> > +        pm_reg_name[i] = get_reg_byname(np, pm_reg_name[i]);
> > +        if (!pm_reg_name[i])
> > +            iounmap(pm_reg_name[i]);
> > +    }
> > +
> > +    of_node_put(np);
> > +    return 0;
> > +}
> > +arch_initcall(loongson_fdt_reset_init);
> > +
> >   static void loongson_restart(char *command)
> >   {
> > +    if ((read_c0_prid() & PRID_IMP_MASK) == PRID_IMP_LOONGSON_64R) {
> > +        writel(0x1, (void *)pm_reg_name[2]);
> > +    } else {
> > +        void (*fw_restart)(void) = (void 
> > *)loongson_sysconf.restart_addr;
> >   -    void (*fw_restart)(void) = (void *)loongson_sysconf.restart_addr;
> > +        fw_restart();
> > +    }
> >   -    fw_restart();
> >       while (1) {
> >           if (cpu_wait)
> >               cpu_wait();
> > @@ -34,9 +73,18 @@ static void loongson_restart(char *command)
> >     static void loongson_poweroff(void)
> >   {
> > -    void (*fw_poweroff)(void) = (void *)loongson_sysconf.poweroff_addr;
> > +    if ((read_c0_prid() & PRID_IMP_MASK) == PRID_IMP_LOONGSON_64R) {
> > +        /* Clear */
> > +        writel((readl((void *)pm_reg_name[0]) & 0xffffffff), (void 
> > *)pm_reg_name[0]);
> > +        /* Sleep Enable | Soft Off*/
> > +        writel(GENMASK(12, 10)|BIT(13), (void *)pm_reg_name[1]);
> > +    } else {
> > +
> > +        void (*fw_poweroff)(void) = (void 
> > *)loongson_sysconf.poweroff_addr;
> > +
> > +        fw_poweroff();
> > +    }
> >   -    fw_poweroff();
> >       while (1) {
> >           if (cpu_wait)
> >               cpu_wait();