ARM: shmobile: R-Mobile: Add SYSC restart handler

Extend the PM domain platform driver for the R-Mobile System Controller (SYSC) to register a restart handler, to be used on various Renesas ARM SoCs (e.g. R-Mobile A1 (r8a7740) and APE6 (r8a73a4), and SH-Mobile AP4 (sh7372) and AG5 (sh73a0)).

Note that this supports DT-based platforms only.

Signed-off-by Geert Uytterhoeven <[email protected]>

arch/arm/mach-shmobile/pm-rmobile.c +26 -0

+static void __iomem *sysc_base2;
+
+static void rmobile_sysc_restart(enum reboot_mode reboot_mode, const char *cmd)
+{
+	pr_debug("%s %u/%s\n", __func__, reboot_mode, cmd);
+
+	writel(RESCNT2_PRES, sysc_base2 + RESCNT2);
+}
+
+static int rmobile_sysc_probe(struct platform_device *pdev)
+{
+	dev_dbg(&pdev->dev, "%s\n", __func__);
+
+	sysc_base2 = of_iomap(pdev->dev.of_node, 1);
+	if (!sysc_base2)
+		return -ENODEV;
+
+	arm_pm_restart = rmobile_sysc_restart;
+
+	return 0;
+}
+
+static const struct of_device_id rmobile_sysc_of_match[] = {
+	{ .compatible = "renesas,sysc-rmobile", },
+	{ /* sentinel */ }
+};

Quoted 5 lines · On Wednesday 03 December 2014 15:17:04 Geert Uytterhoeven wrote:

Extend the PM domain platform driver for the R-Mobile System Controller (SYSC) to register a restart handler, to be used on various Renesas ARM SoCs (e.g. R-Mobile A1 (r8a7740) and APE6 (r8a73a4), and SH-Mobile AP4 (sh7372) and AG5 (sh73a0)).

Quoted 3 lines

Note that this supports DT-based platforms only.

Signed-off-by Geert Uytterhoeven <[email protected]>

Is this one of the typical system controllers that contains lots of random registers? Maybe you could mark it as "syscon" in DT and just use the existing drivers/power/reset/syscon-reboot.c driver?

Quoted 34 lines

arch/arm/mach-shmobile/pm-rmobile.c +34 -0

+static void __iomem *sysc_base2;
+
+static void rmobile_sysc_restart(enum reboot_mode reboot_mode, const char *cmd)
+{
+     pr_debug("%s %u/%s\n", __func__, reboot_mode, cmd);
+
+     writel(RESCNT2_PRES, sysc_base2 + RESCNT2);
+}
+
+static int rmobile_sysc_probe(struct platform_device *pdev)
+{
+     dev_dbg(&pdev->dev, "%s\n", __func__);
+
+     sysc_base2 = of_iomap(pdev->dev.of_node, 1);
+     if (!sysc_base2)
+             return -ENODEV;
+
+     arm_pm_restart = rmobile_sysc_restart;
+
+     return 0;
+}
+
+static const struct of_device_id rmobile_sysc_of_match[] = {
+     { .compatible = "renesas,sysc-rmobile", },
+     { /* sentinel */ }
+};
+
+static struct platform_driver rmobile_sysc_driver = {
+     .probe = rmobile_sysc_probe,
+     .driver = {
+             .name = "rmobile_sysc",
+             .of_match_table = rmobile_sysc_of_match,
+     },
+};

Review

Quoted 2 lines

(quoted diff) +2 -0

+
+module_platform_driver(rmobile_sysc_driver);

This clearly looks much better than the previous implementation, so that is great. If you can decouple it from the rest of this file, either through syscon or by asserting that sysc_base2 is not going to be needed for anything else, how about moving the new code to a standalon driver in drivers/power/reset?

Quoted 5 lines

This clearly looks much better than the previous implementation, so that is great. If you can decouple it from the rest of this file, either through syscon or by asserting that sysc_base2 is not going to be needed for anything else, how about moving the new code to a standalon driver in drivers/power/reset?

Yes, sysc_base2 is used for reset control only (I don't think we need to read the mode strap pins).

So unless there's a simple solution to the regmap problem, I think moving this driver part to drivers/power/reset is the most viable option.

Hi Simon, Magnus, Arnd,

This patch series extends the PM domain platform driver for the R-Mobile System Controller (SYSC) to register a restart handler, and removes the restart handler hacks on DT-based R-Mobile A1 (r8a7740) and SH-Mobile AG5 (sh73a0) platforms.

Note that this supports DT-based platforms only. Legacy platforms keep on using the restart callback in struct machine_desc.

This was tested on r8a7740/armadillo-multiplatform, sh73a0/kzm9g-reference, and sh73a0/kzm9g-multiplatform.

Arnd: is this what you had in mind in your response to "[GIT PULL] Third Round of Renesas ARM Based Soc Updates for v3.19"
(http://www.spinics.net/lists/arm-kernel/msg379348.html)?

Dependencies:
- The first two patches depend on the series "[PATCH v6 0/7] ARM:
shmobile: R-Mobile: DT PM domain support", as that series adds the SYSC PM domain platform driver for DT-based platforms and adds the SYSC device node to r8a7740.dtsi,

- The last two patches also depend on the series "[PATCH RFC 0/7] ARM:
shmobile: sh73a0: DT PM domain support", as that series adds the SYSC device node to sh73a0.dtsi.

Thanks!

Geert Uytterhoeven (4):
ARM: shmobile: R-Mobile: Add SYSC restart handler
ARM: shmobile: r8a7740: Remove restart callback
ARM: shmobile: sh73a0: Remove restart callback
ARM: shmobile: kzm9g-reference: Remove restart callback

 arch/arm/mach-shmobile/board-kzm9g-reference.c |  8 -----
 arch/arm/mach-shmobile/pm-rmobile.c            | 48 +++++++++++++++++++++++++-
 arch/arm/mach-shmobile/setup-r8a7740.c         |  8 -----
 arch/arm/mach-shmobile/setup-sh73a0.c          |  8 -----
 4 files changed, 47 insertions(+), 25 deletions(-)

Signature · 12 lines

1.9.1

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

Quoted 15 lines · Geert Uytterhoeven

This patch series extends the PM domain platform driver for the R-Mobile System Controller (SYSC) to register a restart handler, and removes the restart handler hacks on DT-based R-Mobile A1 (r8a7740) and SH-Mobile AG5 (sh73a0) platforms.

Note that this supports DT-based platforms only. Legacy platforms keep on using the restart callback in struct machine_desc.

This was tested on r8a7740/armadillo-multiplatform, sh73a0/kzm9g-reference, and sh73a0/kzm9g-multiplatform.

Arnd: is this what you had in mind in your response to "[GIT PULL] Third Round of Renesas ARM Based Soc Updates for v3.19"
(http://www.spinics.net/lists/arm-kernel/msg379348.html)?

Quoted 5 lines

Dependencies:
- The first two patches depend on the series "[PATCH v6 0/7] ARM:
shmobile: R-Mobile: DT PM domain support", as that series adds the SYSC PM domain platform driver for DT-based platforms and adds the SYSC device node to r8a7740.dtsi,

As I have queued up that series I believe I could also queue up the first two patches of this series. Is that worthwhile?

Hi Simon,

Quoted 22 lines · Simon Horman

Quoted 20 lines · Geert Uytterhoeven

This patch series extends the PM domain platform driver for the R-Mobile System Controller (SYSC) to register a restart handler, and removes the restart handler hacks on DT-based R-Mobile A1 (r8a7740) and SH-Mobile AG5 (sh73a0) platforms.

Note that this supports DT-based platforms only. Legacy platforms keep on using the restart callback in struct machine_desc.

This was tested on r8a7740/armadillo-multiplatform, sh73a0/kzm9g-reference, and sh73a0/kzm9g-multiplatform.

Arnd: is this what you had in mind in your response to "[GIT PULL] Third Round of Renesas ARM Based Soc Updates for v3.19"
(http://www.spinics.net/lists/arm-kernel/msg379348.html)?

Dependencies:
- The first two patches depend on the series "[PATCH v6 0/7] ARM:
shmobile: R-Mobile: DT PM domain support", as that series adds the SYSC PM domain platform driver for DT-based platforms and adds the SYSC device node to r8a7740.dtsi,

Quoted 2 lines

As I have queued up that series I believe I could also queue up the first two patches of this series. Is that worthwhile?

Yes you can, if Arnd doesn't object against the driver.