"Hald, Ulrik Bech" <ubh@xxxxxx> writes: >> -----Original Message----- >> From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx] >> Sent: Tuesday, June 09, 2009 9:47 AM >> To: Hald, Ulrik Bech >> Cc: linux-omap@xxxxxxxxxxxxxxx >> Subject: Re: [PATCH 2/3] OMAP3:WDT:Enable support for IVA and SECURE >> >> Ulrik Bech Hald <ubh@xxxxxx> writes: >> >> > This patch enables the IVA and SECURE WDTs in the omap_wdt >> > driver for omap34xx family. SECURE will be available as /dev/watchdog1 >> > HS/EMU devices and IVA will be available as /dev/watchdog3. >> > MPU will be available as /dev/watchdog2 >> > For omap versions earlier than 34xx only MPU watchdog is present and >> > will be available as /dev/watchdog for backwards compatibility. >> > >> > Signed-off-by: Ulrik Bech Hald <ubh@xxxxxx> >> > --- >> > drivers/watchdog/omap_wdt.c | 42 +++++++++++++++++++++++++++++++++++- >> ------ >> > 1 files changed, 35 insertions(+), 7 deletions(-) >> > mode change 100644 => 100755 drivers/watchdog/omap_wdt.c >> > >> > diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c >> >> [...] >> >> > static int omap_wdt_open(struct inode *inode, struct file *file) >> > { >> > - struct omap_wdt_dev *wdev = platform_get_drvdata(omap_wdt_dev); >> > - void __iomem *base = wdev->base; >> > + struct omap_wdt_dev *wdev; >> > + void __iomem *base; >> > + >> > + /* by default MPU wdt is present across omap family */ >> > + wdev = platform_get_drvdata(omap_wdt_dev[1]); >> > + >> > + /* if multiple wdts, find match between device node and wdt device >> */ >> > + if (cpu_is_omap34xx()) { >> > + int i; >> > + for (i = 0; i < NUM_WDTS; i++) { >> > + if (omap_wdt_dev[i]) { >> > + wdev = platform_get_drvdata(omap_wdt_dev[i]); >> > + if (iminor(inode) >> > + == wdev->omap_wdt_miscdev.minor) >> > + break; >> > + } >> > + } >> > + } >> > + >> > + base = wdev->base; >> >> Hmm, this does not look right to me. Any use of cpu_is_* in driver >> code usually indicates that something is not quite right. This same >> watchdog IP is used in some DaVinci family processors and needs to be >> reused there. >> >> I didn't do the miscdev research, but can't you get the pdev from the >> miscdev.parent, and from there get the right wdev pointer from the >> pdev.drvdata. >> >> Otherwise, drop the cpu_is_* and just do inode checking all the time. >> The way you've done it looks error prone to me. > > I can't really see a to way pair the driver and device other than > doing inode/minor number checking , so I'll just go for the inode > checking without any dependency on cpu_is_xxx(). OK. >> >> > if (test_and_set_bit(1, (unsigned long *)&(wdev->omap_wdt_users))) >> > return -EBUSY; >> > @@ -263,6 +283,7 @@ static int __devinit omap_wdt_probe(struct >> platform_device *pdev) >> > struct resource *res, *mem; >> > struct omap_wdt_dev *wdev; >> > int ret; >> > + static char wdt_name[32]; >> > >> > /* reserve static register mappings */ >> > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> > @@ -271,7 +292,7 @@ static int __devinit omap_wdt_probe(struct >> platform_device *pdev) >> > goto err_get_resource; >> > } >> > >> > - if (omap_wdt_dev) { >> > + if (omap_wdt_dev[pdev->id-1]) { >> > ret = -EBUSY; >> > goto err_busy; >> > } >> > @@ -318,8 +339,14 @@ static int __devinit omap_wdt_probe(struct >> platform_device *pdev) >> > >> > wdev->omap_wdt_miscdev.parent = &pdev->dev; >> > wdev->omap_wdt_miscdev.minor = WATCHDOG_MINOR; >> > - wdev->omap_wdt_miscdev.name = "watchdog"; >> > wdev->omap_wdt_miscdev.fops = &omap_wdt_fops; >> > + wdev->omap_wdt_miscdev.name = "watchdog"; >> > + if (cpu_is_omap34xx()) { >> > + snprintf(wdt_name, sizeof(wdt_name), "watchdog%d", pdev->id); >> > + wdev->omap_wdt_miscdev.name = wdt_name; >> > + if (pdev->id != 2) >> > + wdev->omap_wdt_miscdev.minor = MISC_DYNAMIC_MINOR; >> > + } >> >> Again, red flag: cpu_is_* >> >> It might be more consistent to use pdev->dev->name which is already of >> the form "watchdog.%d". > > Not sure I follow. I don't see a "name" field in struct device, only init_name. Sorry, I meant dev->bus_id. Look at dev_set_name() which creates a bus_id of the form ("%s.%d", pdev->name, pdev->id) > Do you mean just using: > snprintf(wdt_name, sizeof(wdt_name), "watchdog%d", pdev->id); > wdev->omap_wdt_miscdev.name = wdt_name; Using pdev->id is ok, but that's what dev_set_name() does. Note that if you decide to go this route, note that wdt_name doesn't need to be static. The driver core will copy the name field the misc_device. If it wasn't copying, you'd have all of the miscdev.name fields ending up being the same thing since they are all assigned the same pointer. Kevin > ...for all the WDT devices, despite how many are present? > >> >> Any reason not to use MISC_DYNAMIC_MINOR for all of them? > > No particular reason other than I thought that retaining the use of WATCHDOG_MINOR for the MPU WDT case would be appropriate. But it does make the code cleaner to use only MISC_DYNAMIC_MINOR. I'll change it. > > Thanks for reviewing! > >> >> Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
