Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] GPIO/pl061: Add suspend resume capability | Date | Thu, 17 Nov 2011 21:34:31 +0100 |
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On Thursday, November 17, 2011, Viresh Kumar wrote: > From: Deepak Sikri <deepak.sikri@st.com> > > This patch adds the suspend and resume operations in the driver. The patch > ensures the data save and restore for the device registers during the > suspend and resume operations respectively. > > Signed-off-by: Deepak Sikri <deepak.sikri@st.com> > --- > drivers/gpio/gpio-pl061.c | 73 +++++++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 73 insertions(+), 0 deletions(-) > > diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c > index 093c90b..d64dc1c 100644 > --- a/drivers/gpio/gpio-pl061.c > +++ b/drivers/gpio/gpio-pl061.c > @@ -23,6 +23,7 @@ > #include <linux/amba/bus.h> > #include <linux/amba/pl061.h> > #include <linux/slab.h> > +#include <linux/pm.h> > > #define GPIODIR 0x400 > #define GPIOIS 0x404 > @@ -35,6 +36,17 @@ > > #define PL061_GPIO_NR 8 > > +#ifdef CONFIG_PM > +struct gpio_context_save_regs { > + u8 gpio_data; > + u8 gpio_dir; > + u8 gpio_is; > + u8 gpio_ibe; > + u8 gpio_iev; > + u8 gpio_ie; > +}; > +#endif > + > struct pl061_gpio { > /* We use a list of pl061_gpio structs for each trigger IRQ in the main > * interrupts controller of the system. We need this to support systems > @@ -54,6 +66,10 @@ struct pl061_gpio { > void __iomem *base; > unsigned irq_base; > struct gpio_chip gc; > + > +#ifdef CONFIG_PM > + struct gpio_context_save_regs csave_regs; > +#endif > }; > > static int pl061_direction_input(struct gpio_chip *gc, unsigned offset) > @@ -330,6 +346,8 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id) > irq_set_chip_data(i + chip->irq_base, chip); > } > > + amba_set_drvdata(dev, chip); > + > return 0; > > iounmap: > @@ -342,6 +360,60 @@ free_mem: > return ret; > } > > +#ifdef CONFIG_PM > +static int pl061_suspend(struct device *dev) > +{ > + struct pl061_gpio *chip = dev_get_drvdata(dev); > + int offset; > + > + chip->csave_regs.gpio_data = 0; > + chip->csave_regs.gpio_dir = readb(chip->base + GPIODIR); > + chip->csave_regs.gpio_is = readb(chip->base + GPIOIS); > + chip->csave_regs.gpio_ibe = readb(chip->base + GPIOIBE); > + chip->csave_regs.gpio_iev = readb(chip->base + GPIOIEV); > + chip->csave_regs.gpio_ie = readb(chip->base + GPIOIE); > + > + for (offset = 0; offset < PL061_GPIO_NR; offset++) { > + if (chip->csave_regs.gpio_dir & (1 << offset)) > + chip->csave_regs.gpio_data |= > + pl061_get_value(&chip->gc, offset) << offset; > + } > + > + return 0; > +} > + > +static int pl061_resume(struct device *dev) > +{ > + struct pl061_gpio *chip = dev_get_drvdata(dev); > + int offset; > + > + for (offset = 0; offset < PL061_GPIO_NR; offset++) { > + if (chip->csave_regs.gpio_dir & (1 << offset)) > + pl061_direction_output(&chip->gc, offset, > + chip->csave_regs.gpio_data & > + (1 << offset)); > + else > + pl061_direction_input(&chip->gc, offset); > + } > + > + writeb(chip->csave_regs.gpio_is, chip->base + GPIOIS); > + writeb(chip->csave_regs.gpio_ibe, chip->base + GPIOIBE); > + writeb(chip->csave_regs.gpio_iev, chip->base + GPIOIEV); > + writeb(chip->csave_regs.gpio_ie, chip->base + GPIOIE); > + > + return 0; > +} > + > +static const struct dev_pm_ops pl061_dev_pm_ops = { > + .suspend = pl061_suspend, > + .resume = pl061_resume,
Please also include hibernation callbacks here, otherwise your code will break systems with hibernation enabled.
There are convenience macros for that in linux/pm.h, please use one of them.
Thanks, Rafael
> +}; > + > +#define PL061_DEV_PM_OPS (&pl061_dev_pm_ops) > +#else > +#define PL061_DEV_PM_OPS NULL > +#endif > + > static struct amba_id pl061_ids[] = { > { > .id = 0x00041061, > @@ -353,6 +425,7 @@ static struct amba_id pl061_ids[] = { > static struct amba_driver pl061_gpio_driver = { > .drv = { > .name = "pl061_gpio", > + .pm = PL061_DEV_PM_OPS, > }, > .id_table = pl061_ids, > .probe = pl061_probe, >
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