[v6,1/4] gpio: mvebu: Add limited PWM support

Submitted by Ralph Sennhauser on April 14, 2017, 3:40 p.m.

Details

Message ID 20170414154056.32055-2-ralph.sennhauser@gmail.com
State New
Headers show

Commit Message

Ralph Sennhauser April 14, 2017, 3:40 p.m.
From: Andrew Lunn <andrew@lunn.ch>

Armada 370/XP devices can 'blink' GPIO lines with a configurable on
and off period. This can be modelled as a PWM.

However, there are only two sets of PWM configuration registers for
all the GPIO lines. This driver simply allows a single GPIO line per
GPIO chip of 32 lines to be used as a PWM. Attempts to use more return
EBUSY.

Due to the interleaving of registers it is not simple to separate the
PWM driver from the GPIO driver. Thus the GPIO driver has been
extended with a PWM driver.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
URL: https://patchwork.ozlabs.org/patch/427287/
URL: https://patchwork.ozlabs.org/patch/427295/
[Ralph Sennhauser:
  * Port forward
  * Merge PWM portion into gpio-mvebu.c
  * Switch to atomic PWM API
  * Add new compatible string marvell,armada-370-xp-gpio
  * Update and merge documentation patch
  * Update MAINTAINERS]
Signed-off-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/gpio/gpio-mvebu.txt        |  32 ++
 MAINTAINERS                                        |   2 +
 drivers/gpio/gpio-mvebu.c                          | 327 ++++++++++++++++++++-
 3 files changed, 349 insertions(+), 12 deletions(-)

Comments

Linus Walleij April 24, 2017, 9:18 a.m.
On Fri, Apr 14, 2017 at 5:40 PM, Ralph Sennhauser
<ralph.sennhauser@gmail.com> wrote:

> From: Andrew Lunn <andrew@lunn.ch>
>
> Armada 370/XP devices can 'blink' GPIO lines with a configurable on
> and off period. This can be modelled as a PWM.
>
> However, there are only two sets of PWM configuration registers for
> all the GPIO lines. This driver simply allows a single GPIO line per
> GPIO chip of 32 lines to be used as a PWM. Attempts to use more return
> EBUSY.
>
> Due to the interleaving of registers it is not simple to separate the
> PWM driver from the GPIO driver. Thus the GPIO driver has been
> extended with a PWM driver.
>
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> URL: https://patchwork.ozlabs.org/patch/427287/
> URL: https://patchwork.ozlabs.org/patch/427295/
> [Ralph Sennhauser:
>   * Port forward
>   * Merge PWM portion into gpio-mvebu.c
>   * Switch to atomic PWM API
>   * Add new compatible string marvell,armada-370-xp-gpio
>   * Update and merge documentation patch
>   * Update MAINTAINERS]
> Signed-off-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
> Tested-by: Andrew Lunn <andrew@lunn.ch>
> Acked-by: Thierry Reding <thierry.reding@gmail.com>
> Acked-by: Rob Herring <robh@kernel.org>

Patch applied.

Yours,
Linus Walleij
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Gregory CLEMENT May 30, 2017, 1:40 p.m.
Hi Ralph and Linus,

I resurrect this thread following the series post by Richard Genoud:
http://lists.infradead.org/pipermail/linux-arm-kernel/2017-May/509461.html

 On lun., avril 24 2017, Linus Walleij <linus.walleij@linaro.org> wrote:

> On Fri, Apr 14, 2017 at 5:40 PM, Ralph Sennhauser
> <ralph.sennhauser@gmail.com> wrote:
>
>> From: Andrew Lunn <andrew@lunn.ch>
>>
>> Armada 370/XP devices can 'blink' GPIO lines with a configurable on
>> and off period. This can be modelled as a PWM.
>>
>> However, there are only two sets of PWM configuration registers for
>> all the GPIO lines. This driver simply allows a single GPIO line per
>> GPIO chip of 32 lines to be used as a PWM. Attempts to use more return
>> EBUSY.
>>
>> Due to the interleaving of registers it is not simple to separate the
>> PWM driver from the GPIO driver. Thus the GPIO driver has been
>> extended with a PWM driver.
>>
>> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
>> URL: https://patchwork.ozlabs.org/patch/427287/
>> URL: https://patchwork.ozlabs.org/patch/427295/
>> [Ralph Sennhauser:
>>   * Port forward
>>   * Merge PWM portion into gpio-mvebu.c
>>   * Switch to atomic PWM API
>>   * Add new compatible string marvell,armada-370-xp-gpio

The fact that Richard managed to run the code on Armada 38x draw my
attention on the documentation that need to be amend.

And it makes me realized that I missed the bad naming of the compatible
string. We don't use family name for the compatible string, but the name
of the first SoC compatible with. So in this case we should use
"marvell,armada-370", as it is still in rc and not yet deployed. What
about fixing the name now?

I can send a patch for it if you want and fix the dts that are still in
my mvebu branch.

Thanks,

Gregory


>>   * Update and merge documentation patch
>>   * Update MAINTAINERS]
>> Signed-off-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
>> Tested-by: Andrew Lunn <andrew@lunn.ch>
>> Acked-by: Thierry Reding <thierry.reding@gmail.com>
>> Acked-by: Rob Herring <robh@kernel.org>
>
> Patch applied.
>
> Yours,
> Linus Walleij
Ralph Sennhauser May 30, 2017, 2:51 p.m.
On Tue, 30 May 2017 15:40:00 +0200
Gregory CLEMENT <gregory.clement@free-electrons.com> wrote:

> Hi Ralph and Linus,
> 
> I resurrect this thread following the series post by Richard Genoud:
> http://lists.infradead.org/pipermail/linux-arm-kernel/2017-May/509461.html
> 
>  On lun., avril 24 2017, Linus Walleij <linus.walleij@linaro.org>
> wrote:
> 
> > On Fri, Apr 14, 2017 at 5:40 PM, Ralph Sennhauser
> > <ralph.sennhauser@gmail.com> wrote:
> >  
> >> From: Andrew Lunn <andrew@lunn.ch>
> >>
> >> Armada 370/XP devices can 'blink' GPIO lines with a configurable on
> >> and off period. This can be modelled as a PWM.
> >>
> >> However, there are only two sets of PWM configuration registers for
> >> all the GPIO lines. This driver simply allows a single GPIO line
> >> per GPIO chip of 32 lines to be used as a PWM. Attempts to use
> >> more return EBUSY.
> >>
> >> Due to the interleaving of registers it is not simple to separate
> >> the PWM driver from the GPIO driver. Thus the GPIO driver has been
> >> extended with a PWM driver.
> >>
> >> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> >> URL: https://patchwork.ozlabs.org/patch/427287/
> >> URL: https://patchwork.ozlabs.org/patch/427295/
> >> [Ralph Sennhauser:
> >>   * Port forward
> >>   * Merge PWM portion into gpio-mvebu.c
> >>   * Switch to atomic PWM API
> >>   * Add new compatible string marvell,armada-370-xp-gpio  
> 
> The fact that Richard managed to run the code on Armada 38x draw my
> attention on the documentation that need to be amend.

Hi Gregory

But does it behave as a pwm-fan? I don't have access to the 38x
functional spec (no NDA with Marvell), the one for XP is public.
According to Andrew the 38x doesn't have the blinking hardware and so I
expect the pwm-fan is just an overblown gpio-fan there, additionally
writing some random values to random registers where luck has it nothing
goes wrong.

Kirkwood apparently has blinking support but only at fixed frequency of
10Hz, so not usable for this purpose either.

So to my knowledge it really is just 370 and XP.

> 
> And it makes me realized that I missed the bad naming of the
> compatible string. We don't use family name for the compatible
> string, but the name of the first SoC compatible with. So in this
> case we should use "marvell,armada-370", as it is still in rc and not
> yet deployed. What about fixing the name now?

I don't mind but certainly not for me to decide at this point.

> 
> I can send a patch for it if you want and fix the dts that are still
> in my mvebu branch.

Sure, or if you prefer I can do it as well if we decide for the change.
No preference.

Ralph
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Richard Genoud May 30, 2017, 3:35 p.m.
2017-05-30 16:51 GMT+02:00 Ralph Sennhauser <ralph.sennhauser@gmail.com>:
> On Tue, 30 May 2017 15:40:00 +0200
> Gregory CLEMENT <gregory.clement@free-electrons.com> wrote:
>
>> Hi Ralph and Linus,
>>
>> I resurrect this thread following the series post by Richard Genoud:
>> http://lists.infradead.org/pipermail/linux-arm-kernel/2017-May/509461.html
>>
>>  On lun., avril 24 2017, Linus Walleij <linus.walleij@linaro.org>
>> wrote:
>>
>> > On Fri, Apr 14, 2017 at 5:40 PM, Ralph Sennhauser
>> > <ralph.sennhauser@gmail.com> wrote:
>> >
>> >> From: Andrew Lunn <andrew@lunn.ch>
>> >>
>> >> Armada 370/XP devices can 'blink' GPIO lines with a configurable on
>> >> and off period. This can be modelled as a PWM.
>> >>
>> >> However, there are only two sets of PWM configuration registers for
>> >> all the GPIO lines. This driver simply allows a single GPIO line
>> >> per GPIO chip of 32 lines to be used as a PWM. Attempts to use
>> >> more return EBUSY.
>> >>
>> >> Due to the interleaving of registers it is not simple to separate
>> >> the PWM driver from the GPIO driver. Thus the GPIO driver has been
>> >> extended with a PWM driver.
>> >>
>> >> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
>> >> URL: https://patchwork.ozlabs.org/patch/427287/
>> >> URL: https://patchwork.ozlabs.org/patch/427295/
>> >> [Ralph Sennhauser:
>> >>   * Port forward
>> >>   * Merge PWM portion into gpio-mvebu.c
>> >>   * Switch to atomic PWM API
>> >>   * Add new compatible string marvell,armada-370-xp-gpio
>>
>> The fact that Richard managed to run the code on Armada 38x draw my
>> attention on the documentation that need to be amend.
>
> Hi Gregory
>
> But does it behave as a pwm-fan? I don't have access to the 38x
> functional spec (no NDA with Marvell), the one for XP is public.
> According to Andrew the 38x doesn't have the blinking hardware and so I
> expect the pwm-fan is just an overblown gpio-fan there, additionally
> writing some random values to random registers where luck has it nothing
> goes wrong.
>
> Kirkwood apparently has blinking support but only at fixed frequency of
> 10Hz, so not usable for this purpose either.
>
> So to my knowledge it really is just 370 and XP.
Hi Ralph,

I have the functional spec (no NDA needed, but it's not the full one) :
A38x-Functional-Spec-PU0A.pdf
https://marvellcorp.wufoo.com/forms/marvell-armada-38x-functional-specifications/
(just an email needed, no blood signing nor chicken slaughtering)
There are the GPIO Blink Counter A/B is ON/OFF Duration Registers as well as the
Blink Enable Registers.

I've done a pwm with different periods (8ms, 4ms, 100ns).
Looking at the scope, it seems to work pretty well :)

>>
>> And it makes me realized that I missed the bad naming of the
>> compatible string. We don't use family name for the compatible
>> string, but the name of the first SoC compatible with. So in this
>> case we should use "marvell,armada-370", as it is still in rc and not
>> yet deployed. What about fixing the name now?
>
> I don't mind but certainly not for me to decide at this point.
>
>>
>> I can send a patch for it if you want and fix the dts that are still
>> in my mvebu branch.
>
> Sure, or if you prefer I can do it as well if we decide for the change.
> No preference.
>
> Ralph
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Ralph Sennhauser May 31, 2017, 12:26 p.m.
On Tue, 30 May 2017 17:35:33 +0200
Richard Genoud <richard.genoud@gmail.com> wrote:
  
> Hi Ralph,
> 
> I have the functional spec (no NDA needed, but it's not the full
> one) : A38x-Functional-Spec-PU0A.pdf
> https://marvellcorp.wufoo.com/forms/marvell-armada-38x-functional-specifications/
> (just an email needed, no blood signing nor chicken slaughtering)
> There are the GPIO Blink Counter A/B is ON/OFF Duration Registers as
> well as the Blink Enable Registers.
> 

Hi Richard,

Thanks for the link, as the terms only talk about materials obtained
from www.marvell.com this one from wufoo.com should be exempt ;)
Also at a glance looks like the complete one. Also says "Functional
Specifications – Unrestricted". Maybe you want to re-download it.

Regardless, as you said the blinking registers are all described. So
it's probably safe to assume 39x will have them as well.

> I've done a pwm with different periods (8ms, 4ms, 100ns).
> Looking at the scope, it seems to work pretty well :)
> 
> >>
> >> And it makes me realized that I missed the bad naming of the
> >> compatible string. We don't use family name for the compatible
> >> string, but the name of the first SoC compatible with. So in this
> >> case we should use "marvell,armada-370", as it is still in rc and
> >> not yet deployed. What about fixing the name now?  

Gregory,

Knowing it's not limited to 370/XP makes "marvell,armada-370-gpio" an
obviously better choice for the compatible string. Guess you didn't
mean to drop the "-gpio" suffix.

Will work on a patch changing the compatible string / documentation for
4.12 and an updated patch for armada 370/XP dtsi as well as a patch
adding the properties to 38x for 4.13+. Expect them tomorrow, probably
won't get around to it today anymore.

Ralph
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Gregory CLEMENT May 31, 2017, 12:36 p.m.
Hi Ralph,
 
 On mer., mai 31 2017, Ralph Sennhauser <ralph.sennhauser@gmail.com> wrote:

> On Tue, 30 May 2017 17:35:33 +0200
> Richard Genoud <richard.genoud@gmail.com> wrote:
>   
>> Hi Ralph,
>> 
>> I have the functional spec (no NDA needed, but it's not the full
>> one) : A38x-Functional-Spec-PU0A.pdf
>> https://marvellcorp.wufoo.com/forms/marvell-armada-38x-functional-specifications/
>> (just an email needed, no blood signing nor chicken slaughtering)
>> There are the GPIO Blink Counter A/B is ON/OFF Duration Registers as
>> well as the Blink Enable Registers.
>> 
>
> Hi Richard,
>
> Thanks for the link, as the terms only talk about materials obtained
> from www.marvell.com this one from wufoo.com should be exempt ;)
> Also at a glance looks like the complete one. Also says "Functional
> Specifications – Unrestricted". Maybe you want to re-download it.
>
> Regardless, as you said the blinking registers are all described. So
> it's probably safe to assume 39x will have them as well.

I guess you meant 38x. (But I suppose it is also true for 39x)


>
>> I've done a pwm with different periods (8ms, 4ms, 100ns).
>> Looking at the scope, it seems to work pretty well :)
>> 
>> >>
>> >> And it makes me realized that I missed the bad naming of the
>> >> compatible string. We don't use family name for the compatible
>> >> string, but the name of the first SoC compatible with. So in this
>> >> case we should use "marvell,armada-370", as it is still in rc and
>> >> not yet deployed. What about fixing the name now?  
>
> Gregory,
>
> Knowing it's not limited to 370/XP makes "marvell,armada-370-gpio" an
> obviously better choice for the compatible string. Guess you didn't
> mean to drop the "-gpio" suffix.

You're right I meant "marvell,armada-370-gpio".

>
> Will work on a patch changing the compatible string / documentation for
> 4.12 and an updated patch for armada 370/XP dtsi as well as a patch
> adding the properties to 38x for 4.13+. Expect them tomorrow, probably
> won't get around to it today anymore.

Great!

Thanks,

Gregory

Patch hide | download patch | download mbox

diff --git a/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt b/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
index a6f3bec..42c3bb2 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
@@ -38,6 +38,24 @@  Required properties:
 - #gpio-cells: Should be two. The first cell is the pin number. The
   second cell is reserved for flags, unused at the moment.
 
+Optional properties:
+
+In order to use the GPIO lines in PWM mode, some additional optional
+properties are required. Only Armada 370 and XP support these properties.
+
+- compatible: Must contain "marvell,armada-370-xp-gpio"
+
+- reg: an additional register set is needed, for the GPIO Blink
+  Counter on/off registers.
+
+- reg-names: Must contain an entry "pwm" corresponding to the
+  additional register range needed for PWM operation.
+
+- #pwm-cells: Should be two. The first cell is the GPIO line number. The
+  second cell is the period in nanoseconds.
+
+- clocks: Must be a phandle to the clock for the GPIO controller.
+
 Example:
 
 		gpio0: gpio@d0018100 {
@@ -51,3 +69,17 @@  Example:
 			#interrupt-cells = <2>;
 			interrupts = <16>, <17>, <18>, <19>;
 		};
+
+		gpio1: gpio@18140 {
+			compatible = "marvell,armada-370-xp-gpio";
+			reg = <0x18140 0x40>, <0x181c8 0x08>;
+			reg-names = "gpio", "pwm";
+			ngpios = <17>;
+			gpio-controller;
+			#gpio-cells = <2>;
+			#pwm-cells = <2>;
+			interrupt-controller;
+			#interrupt-cells = <2>;
+			interrupts = <87>, <88>, <89>;
+			clocks = <&coreclk 0>;
+		};
diff --git a/MAINTAINERS b/MAINTAINERS
index 58b3a22..19382f5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10295,6 +10295,8 @@  F:	include/linux/pwm.h
 F:	drivers/pwm/
 F:	drivers/video/backlight/pwm_bl.c
 F:	include/linux/pwm_backlight.h
+F:	drivers/gpio/gpio-mvebu.c
+F:	Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
 
 PXA2xx/PXA3xx SUPPORT
 M:	Daniel Mack <daniel@zonque.org>
diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index fae4db6..19a92ef 100644
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -42,22 +42,34 @@ 
 #include <linux/io.h>
 #include <linux/of_irq.h>
 #include <linux/of_device.h>
+#include <linux/pwm.h>
 #include <linux/clk.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/irqchip/chained_irq.h>
+#include <linux/platform_device.h>
 #include <linux/bitops.h>
 
+#include "gpiolib.h"
+
 /*
  * GPIO unit register offsets.
  */
-#define GPIO_OUT_OFF		0x0000
-#define GPIO_IO_CONF_OFF	0x0004
-#define GPIO_BLINK_EN_OFF	0x0008
-#define GPIO_IN_POL_OFF		0x000c
-#define GPIO_DATA_IN_OFF	0x0010
-#define GPIO_EDGE_CAUSE_OFF	0x0014
-#define GPIO_EDGE_MASK_OFF	0x0018
-#define GPIO_LEVEL_MASK_OFF	0x001c
+#define GPIO_OUT_OFF			0x0000
+#define GPIO_IO_CONF_OFF		0x0004
+#define GPIO_BLINK_EN_OFF		0x0008
+#define GPIO_IN_POL_OFF			0x000c
+#define GPIO_DATA_IN_OFF		0x0010
+#define GPIO_EDGE_CAUSE_OFF		0x0014
+#define GPIO_EDGE_MASK_OFF		0x0018
+#define GPIO_LEVEL_MASK_OFF		0x001c
+#define GPIO_BLINK_CNT_SELECT_OFF	0x0020
+
+/*
+ * PWM register offsets.
+ */
+#define PWM_BLINK_ON_DURATION_OFF	0x0
+#define PWM_BLINK_OFF_DURATION_OFF	0x4
+
 
 /* The MV78200 has per-CPU registers for edge mask and level mask */
 #define GPIO_EDGE_MASK_MV78200_OFF(cpu)	  ((cpu) ? 0x30 : 0x18)
@@ -78,6 +90,20 @@ 
 
 #define MVEBU_MAX_GPIO_PER_BANK		32
 
+struct mvebu_pwm {
+	void __iomem		*membase;
+	unsigned long		 clk_rate;
+	struct gpio_desc	*gpiod;
+	struct pwm_chip		 chip;
+	spinlock_t		 lock;
+	struct mvebu_gpio_chip	*mvchip;
+
+	/* Used to preserve GPIO/PWM registers across suspend/resume */
+	u32			 blink_select;
+	u32			 blink_on_duration;
+	u32			 blink_off_duration;
+};
+
 struct mvebu_gpio_chip {
 	struct gpio_chip   chip;
 	spinlock_t	   lock;
@@ -87,6 +113,10 @@  struct mvebu_gpio_chip {
 	struct irq_domain *domain;
 	int		   soc_variant;
 
+	/* Used for PWM support */
+	struct clk	  *clk;
+	struct mvebu_pwm  *mvpwm;
+
 	/* Used to preserve GPIO registers across suspend/resume */
 	u32		   out_reg;
 	u32		   io_conf_reg;
@@ -110,6 +140,12 @@  static void __iomem *mvebu_gpioreg_blink(struct mvebu_gpio_chip *mvchip)
 	return mvchip->membase + GPIO_BLINK_EN_OFF;
 }
 
+static void __iomem *mvebu_gpioreg_blink_counter_select(struct mvebu_gpio_chip
+							*mvchip)
+{
+	return mvchip->membase + GPIO_BLINK_CNT_SELECT_OFF;
+}
+
 static void __iomem *mvebu_gpioreg_io_conf(struct mvebu_gpio_chip *mvchip)
 {
 	return mvchip->membase + GPIO_IO_CONF_OFF;
@@ -181,6 +217,20 @@  static void __iomem *mvebu_gpioreg_level_mask(struct mvebu_gpio_chip *mvchip)
 }
 
 /*
+ * Functions returning addresses of individual registers for a given
+ * PWM controller.
+ */
+static void __iomem *mvebu_pwmreg_blink_on_duration(struct mvebu_pwm *mvpwm)
+{
+	return mvpwm->membase + PWM_BLINK_ON_DURATION_OFF;
+}
+
+static void __iomem *mvebu_pwmreg_blink_off_duration(struct mvebu_pwm *mvpwm)
+{
+	return mvpwm->membase + PWM_BLINK_OFF_DURATION_OFF;
+}
+
+/*
  * Functions implementing the gpio_chip methods
  */
 static void mvebu_gpio_set(struct gpio_chip *chip, unsigned int pin, int value)
@@ -484,6 +534,246 @@  static void mvebu_gpio_irq_handler(struct irq_desc *desc)
 	chained_irq_exit(chip, desc);
 }
 
+/*
+ * Functions implementing the pwm_chip methods
+ */
+static struct mvebu_pwm *to_mvebu_pwm(struct pwm_chip *chip)
+{
+	return container_of(chip, struct mvebu_pwm, chip);
+}
+
+static int mvebu_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
+	struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
+	struct gpio_desc *desc;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&mvpwm->lock, flags);
+
+	if (mvpwm->gpiod) {
+		ret = -EBUSY;
+	} else {
+		desc = gpio_to_desc(mvchip->chip.base + pwm->hwpwm);
+		if (!desc) {
+			ret = -ENODEV;
+			goto out;
+		}
+
+		ret = gpiod_request(desc, "mvebu-pwm");
+		if (ret)
+			goto out;
+
+		ret = gpiod_direction_output(desc, 0);
+		if (ret) {
+			gpiod_free(desc);
+			goto out;
+		}
+
+		mvpwm->gpiod = desc;
+	}
+out:
+	spin_unlock_irqrestore(&mvpwm->lock, flags);
+	return ret;
+}
+
+static void mvebu_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
+	unsigned long flags;
+
+	spin_lock_irqsave(&mvpwm->lock, flags);
+	gpiod_free(mvpwm->gpiod);
+	mvpwm->gpiod = NULL;
+	spin_unlock_irqrestore(&mvpwm->lock, flags);
+}
+
+static void mvebu_pwm_get_state(struct pwm_chip *chip,
+				struct pwm_device *pwm,
+				struct pwm_state *state) {
+
+	struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
+	struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
+	unsigned long long val;
+	unsigned long flags;
+	u32 u;
+
+	spin_lock_irqsave(&mvpwm->lock, flags);
+
+	val = (unsigned long long)
+		readl_relaxed(mvebu_pwmreg_blink_on_duration(mvpwm));
+	val *= NSEC_PER_SEC;
+	do_div(val, mvpwm->clk_rate);
+	if (val > UINT_MAX)
+		state->duty_cycle = UINT_MAX;
+	else if (val)
+		state->duty_cycle = val;
+	else
+		state->duty_cycle = 1;
+
+	val = (unsigned long long)
+		readl_relaxed(mvebu_pwmreg_blink_off_duration(mvpwm));
+	val *= NSEC_PER_SEC;
+	do_div(val, mvpwm->clk_rate);
+	if (val < state->duty_cycle) {
+		state->period = 1;
+	} else {
+		val -= state->duty_cycle;
+		if (val > UINT_MAX)
+			state->period = UINT_MAX;
+		else if (val)
+			state->period = val;
+		else
+			state->period = 1;
+	}
+
+	u = readl_relaxed(mvebu_gpioreg_blink(mvchip));
+	if (u)
+		state->enabled = true;
+	else
+		state->enabled = false;
+
+	spin_unlock_irqrestore(&mvpwm->lock, flags);
+}
+
+static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			   struct pwm_state *state)
+{
+	struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
+	struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
+	unsigned long long val;
+	unsigned long flags;
+	unsigned int on, off;
+
+	val = (unsigned long long) mvpwm->clk_rate * state->duty_cycle;
+	do_div(val, NSEC_PER_SEC);
+	if (val > UINT_MAX)
+		return -EINVAL;
+	if (val)
+		on = val;
+	else
+		on = 1;
+
+	val = (unsigned long long) mvpwm->clk_rate *
+		(state->period - state->duty_cycle);
+	do_div(val, NSEC_PER_SEC);
+	if (val > UINT_MAX)
+		return -EINVAL;
+	if (val)
+		off = val;
+	else
+		off = 1;
+
+	spin_lock_irqsave(&mvpwm->lock, flags);
+
+	writel_relaxed(on, mvebu_pwmreg_blink_on_duration(mvpwm));
+	writel_relaxed(off, mvebu_pwmreg_blink_off_duration(mvpwm));
+	if (state->enabled)
+		mvebu_gpio_blink(&mvchip->chip, pwm->hwpwm, 1);
+	else
+		mvebu_gpio_blink(&mvchip->chip, pwm->hwpwm, 0);
+
+	spin_unlock_irqrestore(&mvpwm->lock, flags);
+
+	return 0;
+}
+
+static const struct pwm_ops mvebu_pwm_ops = {
+	.request = mvebu_pwm_request,
+	.free = mvebu_pwm_free,
+	.get_state = mvebu_pwm_get_state,
+	.apply = mvebu_pwm_apply,
+	.owner = THIS_MODULE,
+};
+
+static void __maybe_unused mvebu_pwm_suspend(struct mvebu_gpio_chip *mvchip)
+{
+	struct mvebu_pwm *mvpwm = mvchip->mvpwm;
+
+	mvpwm->blink_select =
+		readl_relaxed(mvebu_gpioreg_blink_counter_select(mvchip));
+	mvpwm->blink_on_duration =
+		readl_relaxed(mvebu_pwmreg_blink_on_duration(mvpwm));
+	mvpwm->blink_off_duration =
+		readl_relaxed(mvebu_pwmreg_blink_off_duration(mvpwm));
+}
+
+static void __maybe_unused mvebu_pwm_resume(struct mvebu_gpio_chip *mvchip)
+{
+	struct mvebu_pwm *mvpwm = mvchip->mvpwm;
+
+	writel_relaxed(mvpwm->blink_select,
+		       mvebu_gpioreg_blink_counter_select(mvchip));
+	writel_relaxed(mvpwm->blink_on_duration,
+		       mvebu_pwmreg_blink_on_duration(mvpwm));
+	writel_relaxed(mvpwm->blink_off_duration,
+		       mvebu_pwmreg_blink_off_duration(mvpwm));
+}
+
+static int mvebu_pwm_probe(struct platform_device *pdev,
+			   struct mvebu_gpio_chip *mvchip,
+			   int id)
+{
+	struct device *dev = &pdev->dev;
+	struct mvebu_pwm *mvpwm;
+	struct resource *res;
+	u32 set;
+
+	if (!of_device_is_compatible(mvchip->chip.of_node,
+				     "marvell,armada-370-xp-gpio"))
+		return 0;
+
+	if (IS_ERR(mvchip->clk))
+		return PTR_ERR(mvchip->clk);
+
+	/*
+	 * There are only two sets of PWM configuration registers for
+	 * all the GPIO lines on those SoCs which this driver reserves
+	 * for the first two GPIO chips. So if the resource is missing
+	 * we can't treat it as an error.
+	 */
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pwm");
+	if (!res)
+		return 0;
+
+	/*
+	 * Use set A for lines of GPIO chip with id 0, B for GPIO chip
+	 * with id 1. Don't allow further GPIO chips to be used for PWM.
+	 */
+	if (id == 0)
+		set = 0;
+	else if (id == 1)
+		set = U32_MAX;
+	else
+		return -EINVAL;
+	writel_relaxed(0, mvebu_gpioreg_blink_counter_select(mvchip));
+
+	mvpwm = devm_kzalloc(dev, sizeof(struct mvebu_pwm), GFP_KERNEL);
+	if (!mvpwm)
+		return -ENOMEM;
+	mvchip->mvpwm = mvpwm;
+	mvpwm->mvchip = mvchip;
+
+	mvpwm->membase = devm_ioremap_resource(dev, res);
+	if (IS_ERR(mvpwm->membase))
+		return PTR_ERR(mvpwm->membase);
+
+	mvpwm->clk_rate = clk_get_rate(mvchip->clk);
+	if (!mvpwm->clk_rate) {
+		dev_err(dev, "failed to get clock rate\n");
+		return -EINVAL;
+	}
+
+	mvpwm->chip.dev = dev;
+	mvpwm->chip.ops = &mvebu_pwm_ops;
+	mvpwm->chip.npwm = mvchip->chip.ngpio;
+
+	spin_lock_init(&mvpwm->lock);
+
+	return pwmchip_add(&mvpwm->chip);
+}
+
 #ifdef CONFIG_DEBUG_FS
 #include <linux/seq_file.h>
 
@@ -555,6 +845,10 @@  static const struct of_device_id mvebu_gpio_of_match[] = {
 		.data	    = (void *) MVEBU_GPIO_SOC_VARIANT_ARMADAXP,
 	},
 	{
+		.compatible = "marvell,armada-370-xp-gpio",
+		.data	    = (void *) MVEBU_GPIO_SOC_VARIANT_ORION,
+	},
+	{
 		/* sentinel */
 	},
 };
@@ -600,6 +894,9 @@  static int mvebu_gpio_suspend(struct platform_device *pdev, pm_message_t state)
 		BUG();
 	}
 
+	if (IS_ENABLED(CONFIG_PWM))
+		mvebu_pwm_suspend(mvchip);
+
 	return 0;
 }
 
@@ -643,6 +940,9 @@  static int mvebu_gpio_resume(struct platform_device *pdev)
 		BUG();
 	}
 
+	if (IS_ENABLED(CONFIG_PWM))
+		mvebu_pwm_resume(mvchip);
+
 	return 0;
 }
 
@@ -654,7 +954,6 @@  static int mvebu_gpio_probe(struct platform_device *pdev)
 	struct resource *res;
 	struct irq_chip_generic *gc;
 	struct irq_chip_type *ct;
-	struct clk *clk;
 	unsigned int ngpios;
 	bool have_irqs;
 	int soc_variant;
@@ -688,10 +987,10 @@  static int mvebu_gpio_probe(struct platform_device *pdev)
 		return id;
 	}
 
-	clk = devm_clk_get(&pdev->dev, NULL);
+	mvchip->clk = devm_clk_get(&pdev->dev, NULL);
 	/* Not all SoCs require a clock.*/
-	if (!IS_ERR(clk))
-		clk_prepare_enable(clk);
+	if (!IS_ERR(mvchip->clk))
+		clk_prepare_enable(mvchip->clk);
 
 	mvchip->soc_variant = soc_variant;
 	mvchip->chip.label = dev_name(&pdev->dev);
@@ -822,6 +1121,10 @@  static int mvebu_gpio_probe(struct platform_device *pdev)
 						 mvchip);
 	}
 
+	/* Armada 370/XP has simple PWM support for GPIO lines */
+	if (IS_ENABLED(CONFIG_PWM))
+		return mvebu_pwm_probe(pdev, mvchip, id);
+
 	return 0;
 
 err_domain: