[PATCH 6/7] watchdog: OMAP: use standard GETBOOTSTATUS interface; use platform_data fn ptr
Jon Hunter
jon-hunter at ti.com
Thu Oct 25 16:14:49 EDT 2012
Hi Paul,
On 10/15/2012 08:32 PM, Paul Walmsley wrote:
> Previously the OMAP watchdog driver used a non-standard way to report
> the chip reset source via the GETBOOTSTATUS ioctl. This patch
> converts the driver to use the standard WDIOF_* flags for this
> purpose.
>
> This patch may break existing userspace code that uses the existing
> non-standard data format returned by the OMAP watchdog driver's
> GETBOOTSTATUS ioctl. To fetch detailed reset source information,
> userspace code will need to retrieve it directly from the CGRM or PRM
> drivers when those are completed.
>
> Previously, to fetch the reset source, the driver either read a
> register outside the watchdog IP block (OMAP1), or called a function
> exported directly from arch/arm/mach-omap2. Both approaches are
> broken. This patch also converts the driver to use a platform_data
> function pointer. This approach is temporary, and is due to the lack
> of drivers for the OMAP16xx+ Clock Generation and Reset Management IP
> block and the OMAP2+ Power and Reset Management IP block. Once
> drivers are available for those IP blocks, the watchdog driver can be
> converted to call exported drivers from those functions directly.
> At that point, the platform_data function pointer can be removed.
>
> In the short term, this patch is needed to allow the PRM code to be
> removed from arch/arm/mach-omap2 (it is being moved to a driver).
>
> Signed-off-by: Paul Walmsley <paul at pwsan.com>
> Cc: Wim Van Sebroeck <wim at iguana.be>
> ---
> drivers/watchdog/omap_wdt.c | 26 ++++++++++++--------------
> 1 file changed, 12 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c
> index f5db18db..5d33bc0 100644
> --- a/drivers/watchdog/omap_wdt.c
> +++ b/drivers/watchdog/omap_wdt.c
> @@ -46,8 +46,8 @@
> #include <linux/slab.h>
> #include <linux/pm_runtime.h>
> #include <mach/hardware.h>
> -#include <plat/cpu.h>
> -#include <plat/prcm.h>
> +
> +#include <linux/platform_data/omap-wd-timer.h>
>
> #include "omap_wdt.h"
>
> @@ -202,8 +202,10 @@ static ssize_t omap_wdt_write(struct file *file, const char __user *data,
> static long omap_wdt_ioctl(struct file *file, unsigned int cmd,
> unsigned long arg)
> {
> + struct omap_wd_timer_platform_data *pdata;
> struct omap_wdt_dev *wdev;
> - int new_margin;
> + u32 rs;
> + int new_margin, bs;
> static const struct watchdog_info ident = {
> .identity = "OMAP Watchdog",
> .options = WDIOF_SETTIMEOUT,
> @@ -211,6 +213,7 @@ static long omap_wdt_ioctl(struct file *file, unsigned int cmd,
> };
>
> wdev = file->private_data;
> + pdata = wdev->dev->platform_data;
>
> switch (cmd) {
> case WDIOC_GETSUPPORT:
> @@ -219,17 +222,12 @@ static long omap_wdt_ioctl(struct file *file, unsigned int cmd,
> case WDIOC_GETSTATUS:
> return put_user(0, (int __user *)arg);
> case WDIOC_GETBOOTSTATUS:
> -#ifdef CONFIG_ARCH_OMAP1
> - if (cpu_is_omap16xx())
> - return put_user(__raw_readw(ARM_SYSST),
> - (int __user *)arg);
> -#endif
> -#ifdef CONFIG_ARCH_OMAP2PLUS
> - if (cpu_is_omap24xx())
> - return put_user(omap_prcm_get_reset_sources(),
> - (int __user *)arg);
> -#endif
> - return put_user(0, (int __user *)arg);
> + if (!pdata->read_reset_sources)
> + return put_user(0, (int __user *)arg);
In the case of booting with device-tree, pdata could be null and so
should we check for this too? In other words ...
+ if (!pdata || !pdata->read_reset_sources)
+ return put_user(0, (int __user *)arg);
Cheers
Jon
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