Intel Elkhart Lake PSE includes two instances of PWM as a single PCI
function with 8 channels each. Add support for the remaining channels.
Signed-off-by: Raag Jadav <[email protected]>
Tested-by: Lakshmi Sowjanya D <[email protected]>
---
drivers/pwm/pwm-dwc.c | 51 +++++++++++++++++++++++++++++++++++--------
drivers/pwm/pwm-dwc.h | 5 +++++
2 files changed, 47 insertions(+), 9 deletions(-)
diff --git a/drivers/pwm/pwm-dwc.c b/drivers/pwm/pwm-dwc.c
index 4929354f8cd9..fd64313cb38d 100644
--- a/drivers/pwm/pwm-dwc.c
+++ b/drivers/pwm/pwm-dwc.c
@@ -25,16 +25,48 @@
#include "pwm-dwc.h"
+/* Elkhart Lake */
+static const struct dwc_pwm_info ehl_pwm_info = {
+ .nr = 2,
+ .size = 0x1000,
+};
+
+static int dwc_pwm_init(struct device *dev, const struct dwc_pwm_info *info, void __iomem *base)
+{
+ /* Default values for single instance devices */
+ unsigned int nr = 1, size = 0;
+ int i, ret;
+
+ /* Fill up values from driver_data, if any */
+ if (info) {
+ nr = info->nr;
+ size = info->size;
+ }
+
+ for (i = 0; i < nr; i++) {
+ struct dwc_pwm *dwc;
+
+ dwc = dwc_pwm_alloc(dev);
+ if (!dwc)
+ return -ENOMEM;
+
+ dwc->base = base + (i * size);
+
+ ret = devm_pwmchip_add(dev, &dwc->chip);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
static int dwc_pwm_probe(struct pci_dev *pci, const struct pci_device_id *id)
{
+ const struct dwc_pwm_info *info;
struct device *dev = &pci->dev;
- struct dwc_pwm *dwc;
+ void __iomem *base;
int ret;
- dwc = dwc_pwm_alloc(dev);
- if (!dwc)
- return -ENOMEM;
-
ret = pcim_enable_device(pci);
if (ret) {
dev_err(dev, "Failed to enable device (%pe)\n", ERR_PTR(ret));
@@ -49,13 +81,14 @@ static int dwc_pwm_probe(struct pci_dev *pci, const struct pci_device_id *id)
return ret;
}
- dwc->base = pcim_iomap_table(pci)[0];
- if (!dwc->base) {
+ base = pcim_iomap_table(pci)[0];
+ if (!base) {
dev_err(dev, "Base address missing\n");
return -ENOMEM;
}
- ret = devm_pwmchip_add(dev, &dwc->chip);
+ info = (const struct dwc_pwm_info *)id->driver_data;
+ ret = dwc_pwm_init(dev, info, base);
if (ret)
return ret;
@@ -109,7 +142,7 @@ static int dwc_pwm_resume(struct device *dev)
static DEFINE_SIMPLE_DEV_PM_OPS(dwc_pwm_pm_ops, dwc_pwm_suspend, dwc_pwm_resume);
static const struct pci_device_id dwc_pwm_id_table[] = {
- { PCI_VDEVICE(INTEL, 0x4bb7) }, /* Elkhart Lake */
+ { PCI_VDEVICE(INTEL, 0x4bb7), (kernel_ulong_t)&ehl_pwm_info },
{ } /* Terminating Entry */
};
MODULE_DEVICE_TABLE(pci, dwc_pwm_id_table);
diff --git a/drivers/pwm/pwm-dwc.h b/drivers/pwm/pwm-dwc.h
index 64795247c54c..c9bbfc77b568 100644
--- a/drivers/pwm/pwm-dwc.h
+++ b/drivers/pwm/pwm-dwc.h
@@ -33,6 +33,11 @@ MODULE_IMPORT_NS(dwc_pwm);
#define DWC_TIM_CTRL_INT_MASK BIT(2)
#define DWC_TIM_CTRL_PWM BIT(3)
+struct dwc_pwm_info {
+ unsigned int nr;
+ unsigned int size;
+};
+
struct dwc_pwm_ctx {
u32 cnt;
u32 cnt2;
--
2.35.3
On Mon, Jan 22, 2024 at 08:32:36AM +0530, Raag Jadav wrote:
> Intel Elkhart Lake PSE includes two instances of PWM as a single PCI
> function with 8 channels each. Add support for the remaining channels.
..
> +static int dwc_pwm_init(struct device *dev, const struct dwc_pwm_info *info, void __iomem *base)
> +{
> + /* Default values for single instance devices */
> + unsigned int nr = 1, size = 0;
> + int i, ret;
> +
> + /* Fill up values from driver_data, if any */
> + if (info) {
> + nr = info->nr;
> + size = info->size;
> + }
> +
> + for (i = 0; i < nr; i++) {
> + struct dwc_pwm *dwc;
> +
> + dwc = dwc_pwm_alloc(dev);
> + if (!dwc)
> + return -ENOMEM;
> +
> + dwc->base = base + (i * size);
> +
> + ret = devm_pwmchip_add(dev, &dwc->chip);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
Why not doing this slightly differently?
First option: Always provide driver data (info is never NULL).
Second option, have the body of the for-loop be factored to a helper
dwc_pwm_init_one() and here
if (!info)
return dwc_pwm_init_one(..., 1, 0);
for (i = 0; i < info->nr; i++) {
ret = dwc_pwm_init_one(...);
if (ret)
return ret;
}
--
With Best Regards,
Andy Shevchenko
On Sun, Jan 28, 2024 at 04:53:24PM +0200, Andy Shevchenko wrote:
> On Mon, Jan 22, 2024 at 08:32:36AM +0530, Raag Jadav wrote:
> > Intel Elkhart Lake PSE includes two instances of PWM as a single PCI
> > function with 8 channels each. Add support for the remaining channels.
>
> ...
>
> > +static int dwc_pwm_init(struct device *dev, const struct dwc_pwm_info *info, void __iomem *base)
> > +{
> > + /* Default values for single instance devices */
> > + unsigned int nr = 1, size = 0;
> > + int i, ret;
> > +
> > + /* Fill up values from driver_data, if any */
> > + if (info) {
> > + nr = info->nr;
> > + size = info->size;
> > + }
> > +
> > + for (i = 0; i < nr; i++) {
> > + struct dwc_pwm *dwc;
> > +
> > + dwc = dwc_pwm_alloc(dev);
> > + if (!dwc)
> > + return -ENOMEM;
> > +
> > + dwc->base = base + (i * size);
> > +
> > + ret = devm_pwmchip_add(dev, &dwc->chip);
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
>
> Why not doing this slightly differently?
>
> First option: Always provide driver data (info is never NULL).
Allowing empty driver_data would save us from adding dummy info
for single instance devices in the future.
> Second option, have the body of the for-loop be factored to a helper
> dwc_pwm_init_one() and here
>
> if (!info)
> return dwc_pwm_init_one(..., 1, 0);
>
> for (i = 0; i < info->nr; i++) {
> ret = dwc_pwm_init_one(...);
> if (ret)
> return ret;
> }
Considering above, we're looking at something like this.
static int dwc_pwm_init_one(struct device *dev, void __iomem *base, unsigned int size)
{
struct dwc_pwm *dwc;
dwc = dwc_pwm_alloc(dev);
if (!dwc)
return -ENOMEM;
dwc->base = base + size;
return devm_pwmchip_add(dev, &dwc->chip);
}
...
if (info) {
for (i = 0; i < info->nr; i++) {
ret = dwc_pwm_init_one(dev, base, i * info->size);
if (ret)
return ret;
}
} else {
ret = dwc_pwm_init_one(dev, base, 0);
if (ret)
return ret;
}
...
Raag
On Tue, Jan 30, 2024 at 12:30:23PM +0200, Raag Jadav wrote:
> On Sun, Jan 28, 2024 at 04:53:24PM +0200, Andy Shevchenko wrote:
> > On Mon, Jan 22, 2024 at 08:32:36AM +0530, Raag Jadav wrote:
> > > Intel Elkhart Lake PSE includes two instances of PWM as a single PCI
> > > function with 8 channels each. Add support for the remaining channels.
..
> > First option: Always provide driver data (info is never NULL).
>
> Allowing empty driver_data would save us from adding dummy info
> for single instance devices in the future.
Which may be too premature "optimisation". Why? Because if we ever have
something like pci_dev_get_match_data(), the empty will mean NULL, and
we may not get difference between empty and missing one.
> > Second option, have the body of the for-loop be factored to a helper
> > dwc_pwm_init_one() and here
> >
> > if (!info)
> > return dwc_pwm_init_one(..., 1, 0);
> >
> > for (i = 0; i < info->nr; i++) {
> > ret = dwc_pwm_init_one(...);
> > if (ret)
> > return ret;
> > }
>
> Considering above, we're looking at something like this.
As one option, yes.
> static int dwc_pwm_init_one(struct device *dev, void __iomem *base, unsigned int size)
> {
> struct dwc_pwm *dwc;
>
> dwc = dwc_pwm_alloc(dev);
> if (!dwc)
> return -ENOMEM;
>
> dwc->base = base + size;
>
> return devm_pwmchip_add(dev, &dwc->chip);
> }
--
With Best Regards,
Andy Shevchenko
On Thu, Feb 01, 2024 at 01:26:53PM +0200, Andy Shevchenko wrote:
> On Tue, Jan 30, 2024 at 12:30:23PM +0200, Raag Jadav wrote:
> > On Sun, Jan 28, 2024 at 04:53:24PM +0200, Andy Shevchenko wrote:
> > > On Mon, Jan 22, 2024 at 08:32:36AM +0530, Raag Jadav wrote:
> > > > Intel Elkhart Lake PSE includes two instances of PWM as a single PCI
> > > > function with 8 channels each. Add support for the remaining channels.
>
> ...
>
> > > First option: Always provide driver data (info is never NULL).
> >
> > Allowing empty driver_data would save us from adding dummy info
> > for single instance devices in the future.
>
> Which may be too premature "optimisation". Why? Because if we ever have
> something like pci_dev_get_match_data(), the empty will mean NULL, and
> we may not get difference between empty and missing one.
Not sure if I'm able to find such a helper as of now, but fair.
I can change it in v2 if Jarkko is okay with it.
Raag
On Fri, Feb 02, 2024 at 06:02:46AM +0200, Raag Jadav wrote:
> On Thu, Feb 01, 2024 at 01:26:53PM +0200, Andy Shevchenko wrote:
> > On Tue, Jan 30, 2024 at 12:30:23PM +0200, Raag Jadav wrote:
> > > On Sun, Jan 28, 2024 at 04:53:24PM +0200, Andy Shevchenko wrote:
> > > > On Mon, Jan 22, 2024 at 08:32:36AM +0530, Raag Jadav wrote:
> > > > > Intel Elkhart Lake PSE includes two instances of PWM as a single PCI
> > > > > function with 8 channels each. Add support for the remaining channels.
> >
> > ...
> >
> > > > First option: Always provide driver data (info is never NULL).
> > >
> > > Allowing empty driver_data would save us from adding dummy info
> > > for single instance devices in the future.
> >
> > Which may be too premature "optimisation". Why? Because if we ever have
> > something like pci_dev_get_match_data(), the empty will mean NULL, and
> > we may not get difference between empty and missing one.
>
> Not sure if I'm able to find such a helper as of now, but fair.
> I can change it in v2 if Jarkko is okay with it.
Hi Jarkko,
If you agree with Andy's comments, please let me know.
Will send out a v2 accordingly.
Raag
On 2/7/24 13:48, Raag Jadav wrote:
> On Fri, Feb 02, 2024 at 06:02:46AM +0200, Raag Jadav wrote:
>> On Thu, Feb 01, 2024 at 01:26:53PM +0200, Andy Shevchenko wrote:
>>> On Tue, Jan 30, 2024 at 12:30:23PM +0200, Raag Jadav wrote:
>>>> On Sun, Jan 28, 2024 at 04:53:24PM +0200, Andy Shevchenko wrote:
>>>>> On Mon, Jan 22, 2024 at 08:32:36AM +0530, Raag Jadav wrote:
>>>>>> Intel Elkhart Lake PSE includes two instances of PWM as a single PCI
>>>>>> function with 8 channels each. Add support for the remaining channels.
>>>
>>> ...
>>>
>>>>> First option: Always provide driver data (info is never NULL).
>>>>
>>>> Allowing empty driver_data would save us from adding dummy info
>>>> for single instance devices in the future.
>>>
>>> Which may be too premature "optimisation". Why? Because if we ever have
>>> something like pci_dev_get_match_data(), the empty will mean NULL, and
>>> we may not get difference between empty and missing one.
>>
>> Not sure if I'm able to find such a helper as of now, but fair.
>> I can change it in v2 if Jarkko is okay with it.
>
> Hi Jarkko,
>
> If you agree with Andy's comments, please let me know.
> Will send out a v2 accordingly.
>
Ah, sorry, I didn't have opinion.