diff mbox

[PATCHv2,1/1] ARM:vt8500: Convert to use .restart and remove arch_reset()

Message ID 1342615030.5079.YahooMailNeo@web140804.mail.bf1.yahoo.com (mailing list archive)
State New, archived
Headers show

Commit Message

Tony Prisk July 18, 2012, 12:37 p.m. UTC
Changed the existing board files to use .restart in there machine
descriptions.
Removed system.h as it only contained an inline for arch_reset()

Added device tree support for the restart controller.
Device tree support for vt8500 is still a work-in-progress.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
---
 arch/arm/mach-vt8500/Makefile               |    2 +-
 arch/arm/mach-vt8500/bv07.c                 |    3 +
 arch/arm/mach-vt8500/include/mach/restart.h |   17 +++++++
 arch/arm/mach-vt8500/include/mach/system.h  |   13 -----
 arch/arm/mach-vt8500/restart.c              |   64 +++++++++++++++++++++++++++
 arch/arm/mach-vt8500/wm8505_7in.c           |    4 +-
 6 files changed, 88 insertions(+), 15 deletions(-)
 create mode 100644 arch/arm/mach-vt8500/include/mach/restart.h
 delete mode 100644 arch/arm/mach-vt8500/include/mach/system.h
 create mode 100644 arch/arm/mach-vt8500/restart.c

Comments

Alexey Charkov July 18, 2012, 12:52 p.m. UTC | #1
2012/7/18 Tony Prisk <sentientnz@yahoo.co.nz>:
> Changed the existing board files to use .restart in there machine

Looks like a typo here :)

> descriptions.
> Removed system.h as it only contained an inline for arch_reset()
>
> Added device tree support for the restart controller.
> Device tree support for vt8500 is still a work-in-progress.
>
> Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
> ---
>  arch/arm/mach-vt8500/Makefile               |    2 +-
>  arch/arm/mach-vt8500/bv07.c                 |    3 +
>  arch/arm/mach-vt8500/include/mach/restart.h |   17 +++++++
>  arch/arm/mach-vt8500/include/mach/system.h  |   13 -----
>  arch/arm/mach-vt8500/restart.c              |   64 +++++++++++++++++++++++++++
>  arch/arm/mach-vt8500/wm8505_7in.c           |    4 +-
>  6 files changed, 88 insertions(+), 15 deletions(-)
>  create mode 100644 arch/arm/mach-vt8500/include/mach/restart.h
>  delete mode 100644 arch/arm/mach-vt8500/include/mach/system.h
>  create mode 100644 arch/arm/mach-vt8500/restart.c
>
> diff --git a/arch/arm/mach-vt8500/Makefile b/arch/arm/mach-vt8500/Makefile
> index 81aedb7..54e6997 100644
> --- a/arch/arm/mach-vt8500/Makefile
> +++ b/arch/arm/mach-vt8500/Makefile
> @@ -1,4 +1,4 @@
> -obj-y += devices.o gpio.o irq.o timer.o
> +obj-y += devices.o gpio.o irq.o timer.o restart.o
>
>  obj-$(CONFIG_VTWM_VERSION_VT8500) += devices-vt8500.o
>  obj-$(CONFIG_VTWM_VERSION_WM8505) += devices-wm8505.o
> diff --git a/arch/arm/mach-vt8500/bv07.c b/arch/arm/mach-vt8500/bv07.c
> index a464c75..f9fbeb2 100644
> --- a/arch/arm/mach-vt8500/bv07.c
> +++ b/arch/arm/mach-vt8500/bv07.c
> @@ -23,6 +23,7 @@
>
>  #include <asm/mach-types.h>
>  #include <asm/mach/arch.h>
> +#include <mach/restart.h>
>
>  #include "devices.h"
>
> @@ -62,6 +63,7 @@ void __init bv07_init(void)
>      else
>          printk(KERN_ERR "PMC Hibernation register could not be remapped, not enabling power off!\n");
>
> +    wmt_setup_restart();
>      vt8500_set_resources();
>      platform_add_devices(devices, ARRAY_SIZE(devices));
>      vt8500_gpio_init();
> @@ -69,6 +71,7 @@ void __init bv07_init(void)
>
>  MACHINE_START(BV07, "Benign BV07 Mini Netbook")
>      .atag_offset    = 0x100,
> +    .restart    = wmt_restart,
>      .reserve    = vt8500_reserve_mem,
>      .map_io        = vt8500_map_io,
>      .init_irq    = vt8500_init_irq,
> diff --git a/arch/arm/mach-vt8500/include/mach/restart.h b/arch/arm/mach-vt8500/include/mach/restart.h
> new file mode 100644
> index 0000000..89f9b78
> --- /dev/null
> +++ b/arch/arm/mach-vt8500/include/mach/restart.h
> @@ -0,0 +1,17 @@
> +/* linux/arch/arm/mach-vt8500/restart.h
> + *
> + * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +void wmt_setup_restart(void);
> +void wmt_restart(char mode, const char *cmd);
> diff --git a/arch/arm/mach-vt8500/include/mach/system.h b/arch/arm/mach-vt8500/include/mach/system.h
> deleted file mode 100644
> index 58fa801..0000000
> --- a/arch/arm/mach-vt8500/include/mach/system.h
> +++ /dev/null
> @@ -1,13 +0,0 @@
> -/*
> - * arch/arm/mach-vt8500/include/mach/system.h
> - *
> - */
> -#include <asm/io.h>
> -
> -/* PM Software Reset request register */
> -#define VT8500_PMSR_VIRT    0xf8130060
> -
> -static inline void arch_reset(char mode, const char *cmd)
> -{
> -    writel(1, VT8500_PMSR_VIRT);
> -}
> diff --git a/arch/arm/mach-vt8500/restart.c b/arch/arm/mach-vt8500/restart.c
> new file mode 100644
> index 0000000..9134aea
> --- /dev/null
> +++ b/arch/arm/mach-vt8500/restart.c
> @@ -0,0 +1,64 @@
> +/* linux/arch/arm/mach-vt8500/restart.c
> + *
> + * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + */
> +#include <asm/io.h>
> +#include <linux/ioport.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +
> +/* PM Software Reset request register */
> +#define LEGACY_PMSR_REG        0xD8130060
> +#define WMT_PRIZM_PMSR_REG    0x60
> +
> +static void __iomem *wmt_restart_reg;
> +
> +void wmt_setup_restart(void)
> +{
> +    struct device_node *np;
> +    void __iomem *pmc_base;
> +
> +    /*
> +     * Check if Power Mgmt Controller node is present in device tree. If no
> +     * device tree node, use the legacy PMSR value (valid for all current
> +     * SoCs).
> +     */
> +    np = of_find_compatible_node(NULL, NULL, "wmt,prizm-pmc");
> +    if (np) {
> +        pmc_base = of_iomap(np, 0);
> +
> +        if (!pmc_base)
> +            pr_err("%s:of_iomap(pmc) failed\n", __func__);
> +
> +        of_node_put(np);
> +
> +        wmt_restart_reg = (void *)((u32)(pmc_base) + WMT_PRIZM_PMSR_REG);

GCC allows pointer arithmetics on void * directly, and that's relied
upon heavily throughout the kernel code, so you don't need to cast it
here.

> +    } else {
> +        if (!request_mem_region(LEGACY_PMSR_REG, 4, NULL)) {

Is this required? I believe we could drop it just as well.

Thanks,
Alexey
Arnd Bergmann July 18, 2012, 12:59 p.m. UTC | #2
On Wednesday 18 July 2012, Tony Prisk wrote:
> Changed the existing board files to use .restart in there machine
> descriptions.
> Removed system.h as it only contained an inline for arch_reset()
> 
> Added device tree support for the restart controller.
> Device tree support for vt8500 is still a work-in-progress.
> 
> Signed-off-by: Tony Prisk <linux@prisktech.co.nz>

Looks ok from the point of view that it's technically correct.
Let me make some comments about the style though:

> +/* PM Software Reset request register */
> +#define LEGACY_PMSR_REG        0xD8130060
> +#define WMT_PRIZM_PMSR_REG    0x60
> +
> +static void __iomem *wmt_restart_reg;

I think it's better to point this to the pmc_base virtual address,
which is what we commonly do for similar scenarios. This also means
changing the phys address constant here to 0xD8130000, i.e. the
same as the one in the device tree.

> +    /*
> +     * Check if Power Mgmt Controller node is present in device tree. If no
> +     * device tree node, use the legacy PMSR value (valid for all current
> +     * SoCs).
> +     */
> +    np = of_find_compatible_node(NULL, NULL, "wmt,prizm-pmc");
> +    if (np) {
> +        pmc_base = of_iomap(np, 0);
> +
> +        if (!pmc_base)
> +            pr_err("%s:of_iomap(pmc) failed\n", __func__);
> +
> +        of_node_put(np);
> +
> +        wmt_restart_reg = (void *)((u32)(pmc_base) + WMT_PRIZM_PMSR_REG);

The type cast is ugly, wrong and uncessary ;-)

It's ugly because you are casting the same address twice, which you should
never need to do.
It's wrong because you use the wrong target type (should be void __iomem *)
and the intermediate type (u32) relies on the code being compiled for 32
bit. This is probably a safe assumption, but if you have to cast between
a pointer and an integer in the kernel, the idiom is to use 'unsigned long'
as the integer type.

It's also unnecessary because 

	wmt_restart_reg = pmc_base + WMT_PRIZM_PMSR_REG;

has the exact same effect without any of the above disadvantages.

As mentioned, I would not do the calculation here at all but instead
do it below in wmt_restart(), as 

	if (pmc_base)
		writel(1, pmc_base + WMT_PRIZM_PMSR_REG);

	Arnd
diff mbox

Patch

diff --git a/arch/arm/mach-vt8500/Makefile b/arch/arm/mach-vt8500/Makefile
index 81aedb7..54e6997 100644
--- a/arch/arm/mach-vt8500/Makefile
+++ b/arch/arm/mach-vt8500/Makefile
@@ -1,4 +1,4 @@ 
-obj-y += devices.o gpio.o irq.o timer.o
+obj-y += devices.o gpio.o irq.o timer.o restart.o
 
 obj-$(CONFIG_VTWM_VERSION_VT8500) += devices-vt8500.o
 obj-$(CONFIG_VTWM_VERSION_WM8505) += devices-wm8505.o
diff --git a/arch/arm/mach-vt8500/bv07.c b/arch/arm/mach-vt8500/bv07.c
index a464c75..f9fbeb2 100644
--- a/arch/arm/mach-vt8500/bv07.c
+++ b/arch/arm/mach-vt8500/bv07.c
@@ -23,6 +23,7 @@ 
 
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
+#include <mach/restart.h>
 
 #include "devices.h"
 
@@ -62,6 +63,7 @@  void __init bv07_init(void)
     else
         printk(KERN_ERR "PMC Hibernation register could not be remapped, not enabling power off!\n");
 
+    wmt_setup_restart();
     vt8500_set_resources();
     platform_add_devices(devices, ARRAY_SIZE(devices));
     vt8500_gpio_init();
@@ -69,6 +71,7 @@  void __init bv07_init(void)
 
 MACHINE_START(BV07, "Benign BV07 Mini Netbook")
     .atag_offset    = 0x100,
+    .restart    = wmt_restart,
     .reserve    = vt8500_reserve_mem,
     .map_io        = vt8500_map_io,
     .init_irq    = vt8500_init_irq,
diff --git a/arch/arm/mach-vt8500/include/mach/restart.h b/arch/arm/mach-vt8500/include/mach/restart.h
new file mode 100644
index 0000000..89f9b78
--- /dev/null
+++ b/arch/arm/mach-vt8500/include/mach/restart.h
@@ -0,0 +1,17 @@ 
+/* linux/arch/arm/mach-vt8500/restart.h
+ *
+ * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+void wmt_setup_restart(void);
+void wmt_restart(char mode, const char *cmd);
diff --git a/arch/arm/mach-vt8500/include/mach/system.h b/arch/arm/mach-vt8500/include/mach/system.h
deleted file mode 100644
index 58fa801..0000000
--- a/arch/arm/mach-vt8500/include/mach/system.h
+++ /dev/null
@@ -1,13 +0,0 @@ 
-/*
- * arch/arm/mach-vt8500/include/mach/system.h
- *
- */
-#include <asm/io.h>
-
-/* PM Software Reset request register */
-#define VT8500_PMSR_VIRT    0xf8130060
-
-static inline void arch_reset(char mode, const char *cmd)
-{
-    writel(1, VT8500_PMSR_VIRT);
-}
diff --git a/arch/arm/mach-vt8500/restart.c b/arch/arm/mach-vt8500/restart.c
new file mode 100644
index 0000000..9134aea
--- /dev/null
+++ b/arch/arm/mach-vt8500/restart.c
@@ -0,0 +1,64 @@ 
+/* linux/arch/arm/mach-vt8500/restart.c
+ *
+ * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <asm/io.h>
+#include <linux/ioport.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+/* PM Software Reset request register */
+#define LEGACY_PMSR_REG        0xD8130060
+#define WMT_PRIZM_PMSR_REG    0x60
+
+static void __iomem *wmt_restart_reg;
+
+void wmt_setup_restart(void)
+{
+    struct device_node *np;
+    void __iomem *pmc_base;
+
+    /*
+     * Check if Power Mgmt Controller node is present in device tree. If no
+     * device tree node, use the legacy PMSR value (valid for all current
+     * SoCs).
+     */
+    np = of_find_compatible_node(NULL, NULL, "wmt,prizm-pmc");
+    if (np) {
+        pmc_base = of_iomap(np, 0);
+
+        if (!pmc_base)
+            pr_err("%s:of_iomap(pmc) failed\n", __func__);
+
+        of_node_put(np);
+
+        wmt_restart_reg = (void *)((u32)(pmc_base) + WMT_PRIZM_PMSR_REG);
+    } else {
+        if (!request_mem_region(LEGACY_PMSR_REG, 4, NULL)) {
+            pr_err("%s:request_mem_region(rst) failed\n", __func__);
+            return;
+        }
+
+        wmt_restart_reg = ioremap(LEGACY_PMSR_REG, 4);
+        if (!wmt_restart_reg) {
+            pr_err("%s:ioremap(rstc) failed\n", __func__);
+            return;
+        }
+    }
+}
+
+void wmt_restart(char mode, const char *cmd)
+{
+    if (wmt_restart_reg)
+        writel(1, wmt_restart_reg);
+}
diff --git a/arch/arm/mach-vt8500/wm8505_7in.c b/arch/arm/mach-vt8500/wm8505_7in.c
index cf910a9..db19886 100644
--- a/arch/arm/mach-vt8500/wm8505_7in.c
+++ b/arch/arm/mach-vt8500/wm8505_7in.c
@@ -23,6 +23,7 @@ 
 
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
+#include <mach/restart.h>
 
 #include "devices.h"
 
@@ -61,7 +62,7 @@  void __init wm8505_7in_init(void)
         pm_power_off = &vt8500_power_off;
     else
         printk(KERN_ERR "PMC Hibernation register could not be remapped, not enabling power off!\n");
-
+    wmt_setup_restart();
     wm8505_set_resources();
     platform_add_devices(devices, ARRAY_SIZE(devices));
     vt8500_gpio_init();
@@ -69,6 +70,7 @@  void __init wm8505_7in_init(void)
 
 MACHINE_START(WM8505_7IN_NETBOOK, "WM8505 7-inch generic netbook")
     .atag_offset    = 0x100,
+    .restart    = wmt_restart,
     .reserve    = wm8505_reserve_mem,
     .map_io        = wm8505_map_io,
     .init_irq    = wm8505_init_irq,