2014-01-15 01:11:01

by Feng Kan

[permalink] [raw]
Subject: [PATCH V3 0/3] Enable X-Gene platform reboot driver.

Enable X-Gene platform driver for the X-Gene platform. Change the
driver to use syscon to access the system clock unit's system
reset register.

V2 Change:
- Add support for using ACPI resource.

V3 Change:
- Remove the reboot driver's use of acpi resource patch.
- Change the reboot driver to use syscon to parse out
system clock register. Remove the old method of getting
register from the reboot driver directly.
- Remove documentation since its now simple.

Feng Kan (3):
arm64: add reboot dts entry for X-Gene platform.
arm64: Enable system reset via arch Kconfig for X-Gene system.
power: reset: use syscon driver to parse reboot register from scu

arch/arm64/Kconfig | 2 ++
arch/arm64/boot/dts/apm-storm.dtsi | 10 ++++++++++
drivers/power/reset/xgene-reboot.c | 33 +++++++++++++++++----------------
3 files changed, 29 insertions(+), 16 deletions(-)

--
1.7.6.1


2014-01-15 01:11:22

by Feng Kan

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Subject: [PATCH V3 1/3] arm64: add reboot dts entry for X-Gene platform.

Add missing dts entries for the X-Gene reboot driver.

Signed-off-by: Feng Kan <[email protected]>
---
arch/arm64/boot/dts/apm-storm.dtsi | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/arm64/boot/dts/apm-storm.dtsi b/arch/arm64/boot/dts/apm-storm.dtsi
index d37d736..7beac9d 100644
--- a/arch/arm64/boot/dts/apm-storm.dtsi
+++ b/arch/arm64/boot/dts/apm-storm.dtsi
@@ -103,6 +103,11 @@
#size-cells = <2>;
ranges;

+ scu: system-clk-controller@17000000 {
+ compatible = "apm,xgene-scu","syscon";
+ reg = <0x0 0x17000000 0x0 0x400>;
+ };
+
clocks {
#address-cells = <2>;
#size-cells = <2>;
@@ -187,5 +192,10 @@
interrupt-parent = <&gic>;
interrupts = <0x0 0x4c 0x4>;
};
+
+ reboot@17000014 {
+ compatible = "apm,xgene-reboot";
+ apm,scu = <&scu>;
+ };
};
};
--
1.7.6.1

2014-01-15 01:12:12

by Feng Kan

[permalink] [raw]
Subject: [PATCH V3 3/3] power: reset: use syscon driver to parse reboot register from scu

Use the syscon driver to parse out the reboot register map and issue
reboot via the regmap function.

Signed-off-by: Feng Kan <[email protected]>
---
drivers/power/reset/xgene-reboot.c | 75 +++++++++---------------------------
1 files changed, 19 insertions(+), 56 deletions(-)

diff --git a/drivers/power/reset/xgene-reboot.c b/drivers/power/reset/xgene-reboot.c
index ecd55f8..660ed8a 100644
--- a/drivers/power/reset/xgene-reboot.c
+++ b/drivers/power/reset/xgene-reboot.c
@@ -24,80 +24,43 @@
* For system shutdown, this is board specify. If a board designer
* implements GPIO shutdown, use the gpio-poweroff.c driver.
*/
-#include <linux/io.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
-#include <linux/stat.h>
-#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/reboot.h>
#include <asm/system_misc.h>

-struct xgene_reboot_context {
- struct platform_device *pdev;
- void *csr;
- u32 mask;
-};
+#define SCU_SRST 0x14

-static struct xgene_reboot_context *xgene_restart_ctx;
-
-static void xgene_restart(char str, const char *cmd)
+static void xgene_restart(enum reboot_mode reboot_mode, const char *cmd)
{
- struct xgene_reboot_context *ctx = xgene_restart_ctx;
unsigned long timeout;
+ struct regmap *map;
+ unsigned int ret;
+ struct device_node *dn;
+
+ dn = of_find_node_by_name(NULL, "reboot");
+ map = syscon_regmap_lookup_by_phandle(dn, "apm,scu");
+ if (IS_ERR(map)) {
+ ret = PTR_ERR(map);
+ pr_err("Reboot driver failed to get scu regmap: %d\n", ret);
+ return;
+ }

- /* Issue the reboot */
- if (ctx)
- writel(ctx->mask, ctx->csr);
+ regmap_write(map, SCU_SRST, 0x1);

timeout = jiffies + HZ;
while (time_before(jiffies, timeout))
cpu_relax();

- dev_emerg(&ctx->pdev->dev, "Unable to restart system\n");
+ pr_emerg("Unable to restart system\n");
}

-static int xgene_reboot_probe(struct platform_device *pdev)
+static int __init xgene_reboot_init(void)
{
- struct xgene_reboot_context *ctx;
-
- ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
- if (!ctx) {
- dev_err(&pdev->dev, "out of memory for context\n");
- return -ENODEV;
- }
-
- ctx->csr = of_iomap(pdev->dev.of_node, 0);
- if (!ctx->csr) {
- devm_kfree(&pdev->dev, ctx);
- dev_err(&pdev->dev, "can not map resource\n");
- return -ENODEV;
- }
-
- if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask))
- ctx->mask = 0xFFFFFFFF;
-
- ctx->pdev = pdev;
arm_pm_restart = xgene_restart;
- xgene_restart_ctx = ctx;
-
return 0;
}
-
-static struct of_device_id xgene_reboot_of_match[] = {
- { .compatible = "apm,xgene-reboot" },
- {}
-};
-
-static struct platform_driver xgene_reboot_driver = {
- .probe = xgene_reboot_probe,
- .driver = {
- .name = "xgene-reboot",
- .of_match_table = xgene_reboot_of_match,
- },
-};
-
-static int __init xgene_reboot_init(void)
-{
- return platform_driver_register(&xgene_reboot_driver);
-}
device_initcall(xgene_reboot_init);
--
1.7.6.1

2014-01-15 01:12:33

by Feng Kan

[permalink] [raw]
Subject: [PATCH V3 2/3] arm64: Enable system reset via arch Kconfig for X-Gene system.

Select X-Gene reboot driver for X-Gene platform.

Signed-off-by: Feng Kan <[email protected]>
---
arch/arm64/Kconfig | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 249acb9..bfdf029 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -122,6 +122,8 @@ config ARCH_VEXPRESS

config ARCH_XGENE
bool "AppliedMicro X-Gene SOC Family"
+ select POWER_RESET_XGENE
+ select MFD_SYSCON
help
This enables support for AppliedMicro X-Gene SOC Family

--
1.7.6.1

2014-01-17 16:53:18

by Arnd Bergmann

[permalink] [raw]
Subject: Re: [PATCH V3 3/3] power: reset: use syscon driver to parse reboot register from scu

On Wednesday 15 January 2014, Feng Kan wrote:
> +static int __init xgene_reboot_init(void)
> {
> arm_pm_restart = xgene_restart;
> return 0;
> }
> device_initcall(xgene_reboot_init);

This won't work on a generic kernel, since you unconditionally set the
pm_restart function to your own, which is broken for everything else.

Please keep the platform_driver to attach to the reboot device
as you had before. It might be good to turn this into a generic
"syscon-reset" driver that gets both the register number and
the contents to write from the device node.

Arnd

2014-01-17 17:00:23

by Alexander Shiyan

[permalink] [raw]
Subject: Re: [PATCH V3 3/3] power: reset: use syscon driver to parse reboot register from scu

Пятница, 17 января 2014, 17:52 +01:00 от Arnd Bergmann <[email protected]>:
> On Wednesday 15 January 2014, Feng Kan wrote:
> > +static int __init xgene_reboot_init(void)
> > {
> > arm_pm_restart = xgene_restart;
> > return 0;
> > }
> > device_initcall(xgene_reboot_init);
>
> This won't work on a generic kernel, since you unconditionally set the
> pm_restart function to your own, which is broken for everything else.
>
> Please keep the platform_driver to attach to the reboot device
> as you had before. It might be good to turn this into a generic
> "syscon-reset" driver that gets both the register number and
> the contents to write from the device node.

I am not sure but think the new driver for SYSCON GPIOs can be
reused for such purpose:
http://www.spinics.net/lists/devicetree/msg18221.html

---
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