Patchwork [6/7] fsl_pmc: Add API to enable device as wakeup event source

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Submitter chenhui zhao
Date Nov. 4, 2011, 12:39 p.m.
Message ID <1320410349-14600-1-git-send-email-chenhui.zhao@freescale.com>
Download mbox | patch
Permalink /patch/123621/
State Superseded
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Comments

chenhui zhao - Nov. 4, 2011, 12:39 p.m.
Add APIs for setting wakeup source and lossless Ethernet in low power modes.
These APIs can be used by wake-on-packet feature.

Signed-off-by: Dave Liu <daveliu@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Jin Qing <b24347@freescale.com>
Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com>
---
 arch/powerpc/sysdev/fsl_pmc.c |   67 +++++++++++++++++++++++++++++++++++++++++
 arch/powerpc/sysdev/fsl_soc.h |   11 +++++++
 2 files changed, 78 insertions(+), 0 deletions(-)
Scott Wood - Nov. 4, 2011, 9:14 p.m.
On 11/04/2011 07:39 AM, Zhao Chenhui wrote:
> @@ -45,6 +46,72 @@ static int has_lossless;
>   * code can be compatible with both 32-bit & 36-bit */
>  extern void mpc85xx_enter_deep_sleep(u64 ccsrbar, u32 powmgtreq);
>  
> +#ifdef CONFIG_FSL_PMC
> +/**
> + * pmc_enable_wake - enable OF device as wakeup event source
> + * @pdev: platform device affected
> + * @state: PM state from which device will issue wakeup events
> + * @enable: True to enable event generation; false to disable
> + *
> + * This enables the device as a wakeup event source, or disables it.
> + *
> + * RETURN VALUE:
> + * 0 is returned on success
> + * -EINVAL is returned if device is not supposed to wake up the system
> + * Error code depending on the platform is returned if both the platform and
> + * the native mechanism fail to enable the generation of wake-up events
> + */
> +int pmc_enable_wake(struct platform_device *pdev,
> +				suspend_state_t state, bool enable)

"pmc" is too generic for a global function.  If this can be either
enable or disable, perhaps it should be something like
mpc85xx_pmc_set_wake().

> +{
> +	int ret = 0;
> +	struct device_node *clk_np;
> +	u32 *pmcdr_mask;
> +
> +	if (!pmc_regs) {
> +		printk(KERN_WARNING "PMC is unavailable\n");
> +		return -ENOMEM;
> +	}

-ENOMEM is not appropriate here, maybe -ENODEV?

Should print __func__ so the user knows what's complaining.

> +	if (enable && !device_may_wakeup(&pdev->dev))
> +		return -EINVAL;
> +
> +	clk_np = of_parse_phandle(pdev->dev.of_node, "clk-handle", 0);
> +	if (!clk_np)
> +		return -EINVAL;
> +
> +	pmcdr_mask = (u32 *)of_get_property(clk_np, "fsl,pmcdr-mask", NULL);
> +	if (!pmcdr_mask) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	/* clear to enable clock in low power mode */
> +	if (enable)
> +		clrbits32(&pmc_regs->pmcdr, *pmcdr_mask);
> +	else
> +		setbits32(&pmc_regs->pmcdr, *pmcdr_mask);

We should probably initialize PMCDR to all bits set (or at least all
ones we know are valid) -- the default should be "not a wakeup source".

> +/**
> + * pmc_enable_lossless - enable lossless ethernet in low power mode
> + * @enable: True to enable event generation; false to disable
> + */
> +void pmc_enable_lossless(int enable)
> +{
> +	if (enable && has_lossless)
> +		setbits32(&pmc_regs->pmcsr, PMCSR_LOSSLESS);
> +	else
> +		clrbits32(&pmc_regs->pmcsr, PMCSR_LOSSLESS);
> +}
> +EXPORT_SYMBOL_GPL(pmc_enable_lossless);
> +#endif

Won't we overwrite this later?

-Scott
Tabi Timur-B04825 - Nov. 5, 2011, 12:08 a.m.
On Fri, Nov 4, 2011 at 7:39 AM, Zhao Chenhui <chenhui.zhao@freescale.com> wrote:

> +       if (!pmc_regs) {
> +               printk(KERN_WARNING "PMC is unavailable\n");

Use pr_warn() and the other pr_xxx functions.

> +       pmcdr_mask = (u32 *)of_get_property(clk_np, "fsl,pmcdr-mask", NULL);

The typecast is unnecessary here.

> +       /* clear to enable clock in low power mode */
> +       if (enable)
> +               clrbits32(&pmc_regs->pmcdr, *pmcdr_mask);
> +       else
> +               setbits32(&pmc_regs->pmcdr, *pmcdr_mask);

You need to use be32_to_cpup() when dereferencing a pointer to a
device tree property.
chenhui zhao - Nov. 7, 2011, 11:22 a.m.
On Fri, Nov 04, 2011 at 04:14:25PM -0500, Scott Wood wrote:
> On 11/04/2011 07:39 AM, Zhao Chenhui wrote:
> > @@ -45,6 +46,72 @@ static int has_lossless;
> >   * code can be compatible with both 32-bit & 36-bit */
> >  extern void mpc85xx_enter_deep_sleep(u64 ccsrbar, u32 powmgtreq);
> >  
> > +#ifdef CONFIG_FSL_PMC
> > +/**
> > + * pmc_enable_wake - enable OF device as wakeup event source
> > + * @pdev: platform device affected
> > + * @state: PM state from which device will issue wakeup events
> > + * @enable: True to enable event generation; false to disable
> > + *
> > + * This enables the device as a wakeup event source, or disables it.
> > + *
> > + * RETURN VALUE:
> > + * 0 is returned on success
> > + * -EINVAL is returned if device is not supposed to wake up the system
> > + * Error code depending on the platform is returned if both the platform and
> > + * the native mechanism fail to enable the generation of wake-up events
> > + */
> > +int pmc_enable_wake(struct platform_device *pdev,
> > +				suspend_state_t state, bool enable)
> 
> "pmc" is too generic for a global function.  If this can be either
> enable or disable, perhaps it should be something like
> mpc85xx_pmc_set_wake().
> 
> > +{
> > +	int ret = 0;
> > +	struct device_node *clk_np;
> > +	u32 *pmcdr_mask;
> > +
> > +	if (!pmc_regs) {
> > +		printk(KERN_WARNING "PMC is unavailable\n");
> > +		return -ENOMEM;
> > +	}
> 
> -ENOMEM is not appropriate here, maybe -ENODEV?
> 
> Should print __func__ so the user knows what's complaining.
> 
> > +	if (enable && !device_may_wakeup(&pdev->dev))
> > +		return -EINVAL;
> > +
> > +	clk_np = of_parse_phandle(pdev->dev.of_node, "clk-handle", 0);
> > +	if (!clk_np)
> > +		return -EINVAL;
> > +
> > +	pmcdr_mask = (u32 *)of_get_property(clk_np, "fsl,pmcdr-mask", NULL);
> > +	if (!pmcdr_mask) {
> > +		ret = -EINVAL;
> > +		goto out;
> > +	}
> > +
> > +	/* clear to enable clock in low power mode */
> > +	if (enable)
> > +		clrbits32(&pmc_regs->pmcdr, *pmcdr_mask);
> > +	else
> > +		setbits32(&pmc_regs->pmcdr, *pmcdr_mask);
> 
> We should probably initialize PMCDR to all bits set (or at least all
> ones we know are valid) -- the default should be "not a wakeup source".

I think it should be initialized in u-boot.

> 
> > +/**
> > + * pmc_enable_lossless - enable lossless ethernet in low power mode
> > + * @enable: True to enable event generation; false to disable
> > + */
> > +void pmc_enable_lossless(int enable)
> > +{
> > +	if (enable && has_lossless)
> > +		setbits32(&pmc_regs->pmcsr, PMCSR_LOSSLESS);
> > +	else
> > +		clrbits32(&pmc_regs->pmcsr, PMCSR_LOSSLESS);
> > +}
> > +EXPORT_SYMBOL_GPL(pmc_enable_lossless);
> > +#endif
> 
> Won't we overwrite this later?
> 
> -Scott

Do you have any idea?

-chenhui
chenhui zhao - Nov. 7, 2011, 11:24 a.m.
On Fri, Nov 04, 2011 at 07:08:24PM -0500, Tabi Timur-B04825 wrote:
> On Fri, Nov 4, 2011 at 7:39 AM, Zhao Chenhui <chenhui.zhao@freescale.com> wrote:
> 
> > +       if (!pmc_regs) {
> > +               printk(KERN_WARNING "PMC is unavailable\n");
> 
> Use pr_warn() and the other pr_xxx functions.
> 
> > +       pmcdr_mask = (u32 *)of_get_property(clk_np, "fsl,pmcdr-mask", NULL);
> 
> The typecast is unnecessary here.
> 
> > +       /* clear to enable clock in low power mode */
> > +       if (enable)
> > +               clrbits32(&pmc_regs->pmcdr, *pmcdr_mask);
> > +       else
> > +               setbits32(&pmc_regs->pmcdr, *pmcdr_mask);
> 
> You need to use be32_to_cpup() when dereferencing a pointer to a
> device tree property.
> 
> -- 
> Timur Tabi
> Linux kernel developer at Freescale

Thanks. I will fix them all.

-chenhui
Scott Wood - Nov. 7, 2011, 3:49 p.m.
On 11/07/2011 05:22 AM, Zhao Chenhui wrote:
> On Fri, Nov 04, 2011 at 04:14:25PM -0500, Scott Wood wrote:
>> On 11/04/2011 07:39 AM, Zhao Chenhui wrote:
>>> +	if (enable && !device_may_wakeup(&pdev->dev))
>>> +		return -EINVAL;
>>> +
>>> +	clk_np = of_parse_phandle(pdev->dev.of_node, "clk-handle", 0);
>>> +	if (!clk_np)
>>> +		return -EINVAL;
>>> +
>>> +	pmcdr_mask = (u32 *)of_get_property(clk_np, "fsl,pmcdr-mask", NULL);
>>> +	if (!pmcdr_mask) {
>>> +		ret = -EINVAL;
>>> +		goto out;
>>> +	}
>>> +
>>> +	/* clear to enable clock in low power mode */
>>> +	if (enable)
>>> +		clrbits32(&pmc_regs->pmcdr, *pmcdr_mask);
>>> +	else
>>> +		setbits32(&pmc_regs->pmcdr, *pmcdr_mask);
>>
>> We should probably initialize PMCDR to all bits set (or at least all
>> ones we know are valid) -- the default should be "not a wakeup source".
> 
> I think it should be initialized in u-boot.

I don't see it.  If you mean you think this should be added to U-Boot, I
disagree.  U-Boot does not use this, and we should not add gratuitous
U-Boot dependencies to Linux -- especially in cases where there are
existing U-Boots in use for relevant boards, that do not have this.

>>> +/**
>>> + * pmc_enable_lossless - enable lossless ethernet in low power mode
>>> + * @enable: True to enable event generation; false to disable
>>> + */
>>> +void pmc_enable_lossless(int enable)
>>> +{
>>> +	if (enable && has_lossless)
>>> +		setbits32(&pmc_regs->pmcsr, PMCSR_LOSSLESS);
>>> +	else
>>> +		clrbits32(&pmc_regs->pmcsr, PMCSR_LOSSLESS);
>>> +}
>>> +EXPORT_SYMBOL_GPL(pmc_enable_lossless);
>>> +#endif
>>
>> Won't we overwrite this later?
>>
>> -Scott
> 
> Do you have any idea?

Set a flag that the code that enters (deep) sleep can use.

Also, rename function to mpc85xx_pmc_set_lossless_ethernet().

-Scott
Scott Wood - Nov. 7, 2011, 6:41 p.m.
On 11/04/2011 07:08 PM, Tabi Timur-B04825 wrote:
> On Fri, Nov 4, 2011 at 7:39 AM, Zhao Chenhui <chenhui.zhao@freescale.com> wrote:
>> +       /* clear to enable clock in low power mode */
>> +       if (enable)
>> +               clrbits32(&pmc_regs->pmcdr, *pmcdr_mask);
>> +       else
>> +               setbits32(&pmc_regs->pmcdr, *pmcdr_mask);
> 
> You need to use be32_to_cpup() when dereferencing a pointer to a
> device tree property.

Or just use of_property_read_u32().

-Scott
Li Yang-R58472 - Nov. 8, 2011, 11:12 a.m.
>-----Original Message-----
>From: linuxppc-dev-bounces+leoli=freescale.com@lists.ozlabs.org
>[mailto:linuxppc-dev-bounces+leoli=freescale.com@lists.ozlabs.org] On
>Behalf Of Scott Wood
>Sent: Saturday, November 05, 2011 5:14 AM
>To: Zhao Chenhui-B35336
>Cc: netdev@vger.kernel.org; linuxppc-dev@lists.ozlabs.org
>Subject: Re: [PATCH 6/7] fsl_pmc: Add API to enable device as wakeup event
>source
>
>On 11/04/2011 07:39 AM, Zhao Chenhui wrote:
>> @@ -45,6 +46,72 @@ static int has_lossless;
>>   * code can be compatible with both 32-bit & 36-bit */  extern void
>> mpc85xx_enter_deep_sleep(u64 ccsrbar, u32 powmgtreq);
>>
>> +#ifdef CONFIG_FSL_PMC
>> +/**
>> + * pmc_enable_wake - enable OF device as wakeup event source
>> + * @pdev: platform device affected
>> + * @state: PM state from which device will issue wakeup events
>> + * @enable: True to enable event generation; false to disable
>> + *
>> + * This enables the device as a wakeup event source, or disables it.
>> + *
>> + * RETURN VALUE:
>> + * 0 is returned on success
>> + * -EINVAL is returned if device is not supposed to wake up the
>> +system
>> + * Error code depending on the platform is returned if both the
>> +platform and
>> + * the native mechanism fail to enable the generation of wake-up
>> +events  */ int pmc_enable_wake(struct platform_device *pdev,
>> +				suspend_state_t state, bool enable)
>
>"pmc" is too generic for a global function.  If this can be either enable
>or disable, perhaps it should be something like mpc85xx_pmc_set_wake().
>
>> +{
>> +	int ret = 0;
>> +	struct device_node *clk_np;
>> +	u32 *pmcdr_mask;
>> +
>> +	if (!pmc_regs) {
>> +		printk(KERN_WARNING "PMC is unavailable\n");
>> +		return -ENOMEM;
>> +	}
>
>-ENOMEM is not appropriate here, maybe -ENODEV?
>
>Should print __func__ so the user knows what's complaining.
>
>> +	if (enable && !device_may_wakeup(&pdev->dev))
>> +		return -EINVAL;
>> +
>> +	clk_np = of_parse_phandle(pdev->dev.of_node, "clk-handle", 0);
>> +	if (!clk_np)
>> +		return -EINVAL;
>> +
>> +	pmcdr_mask = (u32 *)of_get_property(clk_np, "fsl,pmcdr-mask", NULL);
>> +	if (!pmcdr_mask) {
>> +		ret = -EINVAL;
>> +		goto out;
>> +	}
>> +
>> +	/* clear to enable clock in low power mode */
>> +	if (enable)
>> +		clrbits32(&pmc_regs->pmcdr, *pmcdr_mask);
>> +	else
>> +		setbits32(&pmc_regs->pmcdr, *pmcdr_mask);
>
>We should probably initialize PMCDR to all bits set (or at least all ones
>we know are valid) -- the default should be "not a wakeup source".

Ideally I agree with you.  But currently we only have the UI of changing wake-up source for Ethernet device.  Will do when we can change all of the devices.

>
>> +/**
>> + * pmc_enable_lossless - enable lossless ethernet in low power mode
>> + * @enable: True to enable event generation; false to disable  */
>> +void pmc_enable_lossless(int enable) {
>> +	if (enable && has_lossless)
>> +		setbits32(&pmc_regs->pmcsr, PMCSR_LOSSLESS);
>> +	else
>> +		clrbits32(&pmc_regs->pmcsr, PMCSR_LOSSLESS); }
>> +EXPORT_SYMBOL_GPL(pmc_enable_lossless);
>> +#endif
>
>Won't we overwrite this later?

You are right.  Will remove the code that overwrite this.

- Leo

Patch

diff --git a/arch/powerpc/sysdev/fsl_pmc.c b/arch/powerpc/sysdev/fsl_pmc.c
index 58d35d8..dab8161 100644
--- a/arch/powerpc/sysdev/fsl_pmc.c
+++ b/arch/powerpc/sysdev/fsl_pmc.c
@@ -38,6 +38,7 @@  static struct device *pmc_dev;
 static struct pmc_regs __iomem *pmc_regs;
 
 #define PMCSR_SLP	0x00020000
+#define PMCSR_LOSSLESS	0x00400000
 static int has_deep_sleep;
 static int has_lossless;
 
@@ -45,6 +46,72 @@  static int has_lossless;
  * code can be compatible with both 32-bit & 36-bit */
 extern void mpc85xx_enter_deep_sleep(u64 ccsrbar, u32 powmgtreq);
 
+#ifdef CONFIG_FSL_PMC
+/**
+ * pmc_enable_wake - enable OF device as wakeup event source
+ * @pdev: platform device affected
+ * @state: PM state from which device will issue wakeup events
+ * @enable: True to enable event generation; false to disable
+ *
+ * This enables the device as a wakeup event source, or disables it.
+ *
+ * RETURN VALUE:
+ * 0 is returned on success
+ * -EINVAL is returned if device is not supposed to wake up the system
+ * Error code depending on the platform is returned if both the platform and
+ * the native mechanism fail to enable the generation of wake-up events
+ */
+int pmc_enable_wake(struct platform_device *pdev,
+				suspend_state_t state, bool enable)
+{
+	int ret = 0;
+	struct device_node *clk_np;
+	u32 *pmcdr_mask;
+
+	if (!pmc_regs) {
+		printk(KERN_WARNING "PMC is unavailable\n");
+		return -ENOMEM;
+	}
+
+	if (enable && !device_may_wakeup(&pdev->dev))
+		return -EINVAL;
+
+	clk_np = of_parse_phandle(pdev->dev.of_node, "clk-handle", 0);
+	if (!clk_np)
+		return -EINVAL;
+
+	pmcdr_mask = (u32 *)of_get_property(clk_np, "fsl,pmcdr-mask", NULL);
+	if (!pmcdr_mask) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* clear to enable clock in low power mode */
+	if (enable)
+		clrbits32(&pmc_regs->pmcdr, *pmcdr_mask);
+	else
+		setbits32(&pmc_regs->pmcdr, *pmcdr_mask);
+
+out:
+	of_node_put(clk_np);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pmc_enable_wake);
+
+/**
+ * pmc_enable_lossless - enable lossless ethernet in low power mode
+ * @enable: True to enable event generation; false to disable
+ */
+void pmc_enable_lossless(int enable)
+{
+	if (enable && has_lossless)
+		setbits32(&pmc_regs->pmcsr, PMCSR_LOSSLESS);
+	else
+		clrbits32(&pmc_regs->pmcsr, PMCSR_LOSSLESS);
+}
+EXPORT_SYMBOL_GPL(pmc_enable_lossless);
+#endif
+
 static int pmc_suspend_enter(suspend_state_t state)
 {
 	int ret;
diff --git a/arch/powerpc/sysdev/fsl_soc.h b/arch/powerpc/sysdev/fsl_soc.h
index c6d0073..f4f322a 100644
--- a/arch/powerpc/sysdev/fsl_soc.h
+++ b/arch/powerpc/sysdev/fsl_soc.h
@@ -3,6 +3,8 @@ 
 #ifdef __KERNEL__
 
 #include <asm/mmu.h>
+#include <linux/platform_device.h>
+#include <linux/suspend.h>
 
 struct spi_device;
 
@@ -21,6 +23,15 @@  struct device_node;
 
 extern void fsl_rstcr_restart(char *cmd);
 
+#ifdef CONFIG_FSL_PMC
+int pmc_enable_wake(struct platform_device *pdev, suspend_state_t state,
+		bool enable);
+void pmc_enable_lossless(int enable);
+#else
+#define pmc_enable_wake(pdev, state, enable)
+#define pmc_enable_lossless(enable)
+#endif
+
 #if defined(CONFIG_FB_FSL_DIU) || defined(CONFIG_FB_FSL_DIU_MODULE)
 
 /* The different ports that the DIU can be connected to */