[PATCH v3 0/4] PWM changes for rk3288-evb

[PATCH v3 0/4] PWM changes for rk3288-evb

[Doug Anderson]

These patches enable the PWM backlight for the rk3288-evb board.
There were tested by watching the backlight grow from off to max with
the following instructions:

  cd /sys/class/backlight/backlight*/
  for i in $(seq 255); do echo $i > brightness; sleep .01; done

The first patch enables the proper IP.  I think it could land in
Heiko's tree.

The second patch switches PWM cells from 2 to 3 on rk3288.  I think it
could land in Thierry's tree.  With the PWM subsystem as currently
structured, I believe this will break backward compatibility.  However
the rk3288 PWM driver was added so recently (and the rk3288 is so new)
that this seems OK.  In the worst case if someone yells that they are
broken, I believe we could fix this in Linux by saying that if a PWM
driver specifies 3 cells and the DTS definition of the PWM says 2
cells that we'll just pretend that we have no flags.

The 3rd and 4th patches are DTS ones.  They could land in Heiko's tree
after the second patch has landed.  They are based atop his current
WIP 3.18 dts tree.  Note that instantiating the PWM backlight will
cause the system to hang unless Heiko's (clk: rockchip: protect
critical clocks from getting disabled)
<patchwork.kernel.org/patch/4725391> is landed.

There are no compile time or runtime dependencies between these
patches except that patch #3 needs to come before patch #4.  ...and of
course the PWM won't work without all 4 patches.

Changes in v3:
- Don't store a private copy of polarity.
- Use true instead of 1.
- Cleanup init order with "has_invert".
- Fix space to tab in 2 places in DTS.
- Make sure PWM is upper case in prose.

Changes in v2:
- Check for failed ioremap()

Doug Anderson (4):
  ARM: rockchip: rk3288: Switch to use the proper PWM IP
  pwm: rockchip: Allow polarity invert on rk3288
  ARM: dts: Add main PWM info to rk3288
  ARM: dts: Enable PWM backlight on rk3288-EVB

 .../devicetree/bindings/pwm/pwm-rockchip.txt       |  4 +-
 arch/arm/boot/dts/rk3288-evb.dtsi                  | 53 +++++++++++++++++
 arch/arm/boot/dts/rk3288.dtsi                      | 68 ++++++++++++++++++++++
 arch/arm/mach-rockchip/rockchip.c                  | 24 ++++++++
 drivers/pwm/pwm-rockchip.c                         | 48 ++++++++++++---
 5 files changed, 188 insertions(+), 9 deletions(-)

-- 
2.1.0.rc2.206.gedb03e5

[PATCH v3 1/4] ARM: rockchip: rk3288: Switch to use the proper PWM IP

[Doug Anderson]

The rk3288 SoC has an option to switch all of the PWMs in the system
between the old IP block and the new IP block.  The new IP block is
working and tested and the suggested PWM to use, so setup the SoC to
use it and then we can pretend that the other IP block doesn't exist.

This code could go lots of other places, but we've put it here.  Why?
- Pushing it to the bootloader just makes the code harder to update in
  the field.  If we later find a bug in the new IP block and want to
  change our mind about what to use we want it to be easy to update.
- Putting this code in the driver for IP block is a lot of extra work,
  device tree bindings, etc.  Now that the new IP block is validated
  it's likely no future SoCs will need this code.  Why pollute the PWM
  driver with this?  This is an rk3288 thing so it should be in rk3288
  code.
- There's a single bit that switches over PWMs, which makes it extra
  hard to put this under the PWM device tree nodes.

Signed-off-by: Doug Anderson <dianders@chromium.org>
---
Changes in v3: None
Changes in v2:
- Check for failed ioremap()

 arch/arm/mach-rockchip/rockchip.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/arm/mach-rockchip/rockchip.c b/arch/arm/mach-rockchip/rockchip.c
index 8ab9e0e..93c59f6 100644
--- a/arch/arm/mach-rockchip/rockchip.c
+++ b/arch/arm/mach-rockchip/rockchip.c
@@ -24,6 +24,29 @@
 #include <asm/hardware/cache-l2x0.h>
 #include "core.h"
 
+static void __init rk3288_init_machine(void)
+{
+	void *grf = ioremap(0xff770000, 0x10000);
+
+	if (!grf) {
+		pr_warn("%s: Couldn't map GRF\n", __func__);
+		return;
+	}
+
+	/* Set pwm_sel to RK design PWM in GRF_SOC_CON2; affects all PWMs */
+	writel(0x00010001, grf + 0x24c);
+
+	iounmap(grf);
+}
+
+static void __init rockchip_init_machine(void)
+{
+	if (of_machine_is_compatible("rockchip,rk3288"))
+		rk3288_init_machine();
+
+	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
+}
+
 static const char * const rockchip_board_dt_compat[] = {
 	"rockchip,rk2928",
 	"rockchip,rk3066a",
@@ -34,6 +57,7 @@ static const char * const rockchip_board_dt_compat[] = {
 };
 
 DT_MACHINE_START(ROCKCHIP_DT, "Rockchip Cortex-A9 (Device Tree)")
+	.init_machine	= rockchip_init_machine,
 	.l2c_aux_val	= 0,
 	.l2c_aux_mask	= ~0,
 	.dt_compat	= rockchip_board_dt_compat,
-- 
2.1.0.rc2.206.gedb03e5

[PATCH v3 2/4] pwm: rockchip: Allow polarity invert on rk3288

[Doug Anderson]

The rk3288 has the ability to invert the polarity of the PWM.  Let's
enable that ability.

To do this we increase the number of pwm_cells to 3 to allow using the
PWM_POLARITY_INVERTED flag.  Since the PWM driver on rk3288 is very
new, I thought this was OK.

Signed-off-by: Doug Anderson <dianders@chromium.org>
---
Changes in v3:
- Don't store a private copy of polarity.
- Use true instead of 1.
- Cleanup init order with "has_invert".

Changes in v2: None

 .../devicetree/bindings/pwm/pwm-rockchip.txt       |  4 +-
 drivers/pwm/pwm-rockchip.c                         | 48 ++++++++++++++++++----
 2 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
index d47d15a..b8be3d0 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
@@ -7,8 +7,8 @@ Required properties:
    "rockchip,vop-pwm": found integrated in VOP on RK3288 SoC
  - reg: physical base address and length of the controller's registers
  - clocks: phandle and clock specifier of the PWM reference clock
- - #pwm-cells: should be 2. See pwm.txt in this directory for a
-   description of the cell format.
+ - #pwm-cells: must be 2 (rk2928) or 3 (rk3288). See pwm.txt in this directory
+   for a description of the cell format.
 
 Example:
 
diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index bdd8644..646aed2 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -24,7 +24,9 @@
 #define PWM_ENABLE		(1 << 0)
 #define PWM_CONTINUOUS		(1 << 1)
 #define PWM_DUTY_POSITIVE	(1 << 3)
+#define PWM_DUTY_NEGATIVE	(0 << 3)
 #define PWM_INACTIVE_NEGATIVE	(0 << 4)
+#define PWM_INACTIVE_POSITIVE	(1 << 4)
 #define PWM_OUTPUT_LEFT		(0 << 5)
 #define PWM_LP_DISABLE		(0 << 8)
 
@@ -45,8 +47,10 @@ struct rockchip_pwm_regs {
 struct rockchip_pwm_data {
 	struct rockchip_pwm_regs regs;
 	unsigned int prescaler;
+	bool has_invert;
 
-	void (*set_enable)(struct pwm_chip *chip, bool enable);
+	void (*set_enable)(struct pwm_chip *chip,
+			   struct pwm_device *pwm, bool enable);
 };
 
 static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
@@ -54,7 +58,8 @@ static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
 	return container_of(c, struct rockchip_pwm_chip, chip);
 }
 
-static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
+static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
+				       struct pwm_device *pwm, bool enable)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
@@ -70,14 +75,19 @@ static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
 	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
 }
 
-static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
+static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
+				       struct pwm_device *pwm, bool enable)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
-			  PWM_CONTINUOUS | PWM_DUTY_POSITIVE |
-			  PWM_INACTIVE_NEGATIVE;
+			  PWM_CONTINUOUS;
 	u32 val;
 
+	if (pwm->polarity == PWM_POLARITY_INVERSED)
+		enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
+	else
+		enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
+
 	val = readl_relaxed(pc->base + pc->data->regs.ctrl);
 
 	if (enable)
@@ -124,6 +134,23 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	return 0;
 }
 
+int rockchip_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
+			      enum pwm_polarity polarity)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+
+	if (!pc->data->has_invert)
+		return -ENOSYS;
+
+	/*
+	 * No action needed here because pwm->polarity will be set by the core
+	 * and the core will only change polarity when the PWM is not enabled.
+	 * We'll handle things in set_enable().
+	 */
+
+	return 0;
+}
+
 static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
@@ -133,7 +160,7 @@ static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	if (ret)
 		return ret;
 
-	pc->data->set_enable(chip, true);
+	pc->data->set_enable(chip, pwm, true);
 
 	return 0;
 }
@@ -142,13 +169,14 @@ static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 
-	pc->data->set_enable(chip, false);
+	pc->data->set_enable(chip, pwm, false);
 
 	clk_disable(pc->clk);
 }
 
 static const struct pwm_ops rockchip_pwm_ops = {
 	.config = rockchip_pwm_config,
+	.set_polarity = rockchip_pwm_set_polarity,
 	.enable = rockchip_pwm_enable,
 	.disable = rockchip_pwm_disable,
 	.owner = THIS_MODULE,
@@ -173,6 +201,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = {
 		.ctrl = 0x0c,
 	},
 	.prescaler = 1,
+	.has_invert = true,
 	.set_enable = rockchip_pwm_set_enable_v2,
 };
 
@@ -184,6 +213,7 @@ static const struct rockchip_pwm_data pwm_data_vop = {
 		.ctrl = 0x00,
 	},
 	.prescaler = 1,
+	.has_invert = true,
 	.set_enable = rockchip_pwm_set_enable_v2,
 };
 
@@ -230,6 +260,10 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
 	pc->chip.ops = &rockchip_pwm_ops;
 	pc->chip.base = -1;
 	pc->chip.npwm = 1;
+	if (pc->data->has_invert) {
+		pc->chip.of_xlate = of_pwm_xlate_with_flags;
+		pc->chip.of_pwm_n_cells = 3;
+	}
 
 	ret = pwmchip_add(&pc->chip);
 	if (ret < 0) {
-- 
2.1.0.rc2.206.gedb03e5

[PATCH v3 2/4] pwm: rockchip: Allow polarity invert on rk3288

[Caesar Wang]

Hi Doug,

I reviewed it, the change is need.

Reviewed-on: https://github.com/rkchrome/kernel.git
Reviewed-by: Caesar Wang <caesar.wang@rock-chips.com>

? 2014?08?20? 00:07, Doug Anderson ??:
> The rk3288 has the ability to invert the polarity of the PWM.  Let's
> enable that ability.
>
> To do this we increase the number of pwm_cells to 3 to allow using the
> PWM_POLARITY_INVERTED flag.  Since the PWM driver on rk3288 is very
> new, I thought this was OK.
>
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> ---
> Changes in v3:
> - Don't store a private copy of polarity.
> - Use true instead of 1.
> - Cleanup init order with "has_invert".
>
> Changes in v2: None
>
>   .../devicetree/bindings/pwm/pwm-rockchip.txt       |  4 +-
>   drivers/pwm/pwm-rockchip.c                         | 48 ++++++++++++++++++----
>   2 files changed, 43 insertions(+), 9 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
> index d47d15a..b8be3d0 100644
> --- a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
> +++ b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
> @@ -7,8 +7,8 @@ Required properties:
>      "rockchip,vop-pwm": found integrated in VOP on RK3288 SoC
>    - reg: physical base address and length of the controller's registers
>    - clocks: phandle and clock specifier of the PWM reference clock
> - - #pwm-cells: should be 2. See pwm.txt in this directory for a
> -   description of the cell format.
> + - #pwm-cells: must be 2 (rk2928) or 3 (rk3288). See pwm.txt in this directory
> +   for a description of the cell format.
>   
>   Example:
>   
> diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
> index bdd8644..646aed2 100644
> --- a/drivers/pwm/pwm-rockchip.c
> +++ b/drivers/pwm/pwm-rockchip.c
> @@ -24,7 +24,9 @@
>   #define PWM_ENABLE		(1 << 0)
>   #define PWM_CONTINUOUS		(1 << 1)
>   #define PWM_DUTY_POSITIVE	(1 << 3)
> +#define PWM_DUTY_NEGATIVE	(0 << 3)
>   #define PWM_INACTIVE_NEGATIVE	(0 << 4)
> +#define PWM_INACTIVE_POSITIVE	(1 << 4)
>   #define PWM_OUTPUT_LEFT		(0 << 5)
>   #define PWM_LP_DISABLE		(0 << 8)
>   
> @@ -45,8 +47,10 @@ struct rockchip_pwm_regs {
>   struct rockchip_pwm_data {
>   	struct rockchip_pwm_regs regs;
>   	unsigned int prescaler;
> +	bool has_invert;
>   
> -	void (*set_enable)(struct pwm_chip *chip, bool enable);
> +	void (*set_enable)(struct pwm_chip *chip,
> +			   struct pwm_device *pwm, bool enable);
>   };
>   
>   static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
> @@ -54,7 +58,8 @@ static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
>   	return container_of(c, struct rockchip_pwm_chip, chip);
>   }
>   
> -static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
> +static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
> +				       struct pwm_device *pwm, bool enable)
>   {
>   	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
>   	u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
> @@ -70,14 +75,19 @@ static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
>   	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
>   }
>   
> -static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
> +static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
> +				       struct pwm_device *pwm, bool enable)
>   {
>   	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
>   	u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
> -			  PWM_CONTINUOUS | PWM_DUTY_POSITIVE |
> -			  PWM_INACTIVE_NEGATIVE;
> +			  PWM_CONTINUOUS;
>   	u32 val;
>   
> +	if (pwm->polarity == PWM_POLARITY_INVERSED)
> +		enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
> +	else
> +		enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
> +
>   	val = readl_relaxed(pc->base + pc->data->regs.ctrl);
>   
>   	if (enable)
> @@ -124,6 +134,23 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>   	return 0;
>   }
>   
> +int rockchip_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
> +			      enum pwm_polarity polarity)
> +{
> +	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
> +
> +	if (!pc->data->has_invert)
> +		return -ENOSYS;
> +
> +	/*
> +	 * No action needed here because pwm->polarity will be set by the core
> +	 * and the core will only change polarity when the PWM is not enabled.
> +	 * We'll handle things in set_enable().
> +	 */
> +
> +	return 0;
> +}
> +
>   static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
>   {
>   	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
> @@ -133,7 +160,7 @@ static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
>   	if (ret)
>   		return ret;
>   
> -	pc->data->set_enable(chip, true);
> +	pc->data->set_enable(chip, pwm, true);
>   
>   	return 0;
>   }
> @@ -142,13 +169,14 @@ static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
>   {
>   	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
>   
> -	pc->data->set_enable(chip, false);
> +	pc->data->set_enable(chip, pwm, false);
>   
>   	clk_disable(pc->clk);
>   }
>   
>   static const struct pwm_ops rockchip_pwm_ops = {
>   	.config = rockchip_pwm_config,
> +	.set_polarity = rockchip_pwm_set_polarity,
>   	.enable = rockchip_pwm_enable,
>   	.disable = rockchip_pwm_disable,
>   	.owner = THIS_MODULE,
> @@ -173,6 +201,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = {
>   		.ctrl = 0x0c,
>   	},
>   	.prescaler = 1,
> +	.has_invert = true,
>   	.set_enable = rockchip_pwm_set_enable_v2,
>   };
>   
> @@ -184,6 +213,7 @@ static const struct rockchip_pwm_data pwm_data_vop = {
>   		.ctrl = 0x00,
>   	},
>   	.prescaler = 1,
> +	.has_invert = true,
>   	.set_enable = rockchip_pwm_set_enable_v2,
>   };
>   
> @@ -230,6 +260,10 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
>   	pc->chip.ops = &rockchip_pwm_ops;
>   	pc->chip.base = -1;
>   	pc->chip.npwm = 1;
> +	if (pc->data->has_invert) {
> +		pc->chip.of_xlate = of_pwm_xlate_with_flags;
> +		pc->chip.of_pwm_n_cells = 3;
> +	}
>   
>   	ret = pwmchip_add(&pc->chip);
>   	if (ret < 0) {

-- 
Best regards,
Caesar

[PATCH v3 2/4] pwm: rockchip: Allow polarity invert on rk3288

[Thierry Reding]

On Tue, Aug 19, 2014 at 09:07:54AM -0700, Doug Anderson wrote:
> The rk3288 has the ability to invert the polarity of the PWM.  Let's
> enable that ability.
> 
> To do this we increase the number of pwm_cells to 3 to allow using the
> PWM_POLARITY_INVERTED flag.  Since the PWM driver on rk3288 is very
> new, I thought this was OK.

I don't see any files in arch/arm/boot/dts using either of the
rockchip,vop-pwm or rockchip,rk3288-pwm compatible strings, so there's
no reason to consider this stable ABI yet. As far as I'm concerned the
last sentence can just as well be dropped.

Besides, patches have been posted to support #pwm-cells = <2> and
#pwm-cells = <3> at the same time which should give you backwards-
compatibility for free.

A couple more comments inline.

> diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
[...]
> +int rockchip_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
> +			      enum pwm_polarity polarity)

This should be static.

> +{
> +	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
> +
> +	if (!pc->data->has_invert)
> +		return -ENOSYS;
> +
> +	/*
> +	 * No action needed here because pwm->polarity will be set by the core
> +	 * and the core will only change polarity when the PWM is not enabled.
> +	 * We'll handle things in set_enable().
> +	 */
> +
> +	return 0;
> +}

An alternative here would be to provide a separate pwm_ops with
.set_polarity = NULL for the versions of the IP block that don't support
polarity inversion yet, but this works for me too.

> @@ -173,6 +201,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = {
>  		.ctrl = 0x0c,
>  	},
>  	.prescaler = 1,
> +	.has_invert = true,
>  	.set_enable = rockchip_pwm_set_enable_v2,
>  };
>  
> @@ -184,6 +213,7 @@ static const struct rockchip_pwm_data pwm_data_vop = {
>  		.ctrl = 0x00,
>  	},
>  	.prescaler = 1,
> +	.has_invert = true,
>  	.set_enable = rockchip_pwm_set_enable_v2,
>  };

Can you please add a '.has_invert = false,' line to pwm_data_v1? I know
it's not strictly necessary but I like it when things are explicitly
stated.

>  
> @@ -230,6 +260,10 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
>  	pc->chip.ops = &rockchip_pwm_ops;
>  	pc->chip.base = -1;
>  	pc->chip.npwm = 1;
> +	if (pc->data->has_invert) {

There should be a blank line between the above two.

Thierry
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[PATCH v3 2/4] pwm: rockchip: Allow polarity invert on rk3288

[Doug Anderson]

Thierry,

On Wed, Aug 20, 2014 at 3:04 AM, Thierry Reding
<thierry.reding@gmail.com> wrote:
> On Tue, Aug 19, 2014 at 09:07:54AM -0700, Doug Anderson wrote:
>> The rk3288 has the ability to invert the polarity of the PWM.  Let's
>> enable that ability.
>>
>> To do this we increase the number of pwm_cells to 3 to allow using the
>> PWM_POLARITY_INVERTED flag.  Since the PWM driver on rk3288 is very
>> new, I thought this was OK.
>
> I don't see any files in arch/arm/boot/dts using either of the
> rockchip,vop-pwm or rockchip,rk3288-pwm compatible strings, so there's
> no reason to consider this stable ABI yet. As far as I'm concerned the
> last sentence can just as well be dropped.
>
> Besides, patches have been posted to support #pwm-cells = <2> and
> #pwm-cells = <3> at the same time which should give you backwards-
> compatibility for free.

Done.  I'm happy that the subsystem is being improved to handle
pwm-cells more dynamically, too!  That's a nice improvement.


> A couple more comments inline.
>
>> diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
> [...]
>> +int rockchip_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
>> +                           enum pwm_polarity polarity)
>
> This should be static.

Done.


>> +{
>> +     struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
>> +
>> +     if (!pc->data->has_invert)
>> +             return -ENOSYS;
>> +
>> +     /*
>> +      * No action needed here because pwm->polarity will be set by the core
>> +      * and the core will only change polarity when the PWM is not enabled.
>> +      * We'll handle things in set_enable().
>> +      */
>> +
>> +     return 0;
>> +}
>
> An alternative here would be to provide a separate pwm_ops with
> .set_polarity = NULL for the versions of the IP block that don't support
> polarity inversion yet, but this works for me too.

Good point.  I'll make the change since it paves the way for other
pwm_ops that are different.


>> @@ -173,6 +201,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = {
>>               .ctrl = 0x0c,
>>       },
>>       .prescaler = 1,
>> +     .has_invert = true,
>>       .set_enable = rockchip_pwm_set_enable_v2,
>>  };
>>
>> @@ -184,6 +213,7 @@ static const struct rockchip_pwm_data pwm_data_vop = {
>>               .ctrl = 0x00,
>>       },
>>       .prescaler = 1,
>> +     .has_invert = true,
>>       .set_enable = rockchip_pwm_set_enable_v2,
>>  };
>
> Can you please add a '.has_invert = false,' line to pwm_data_v1? I know
> it's not strictly necessary but I like it when things are explicitly
> stated.

No longer relevant with different pwm_ops.


>> @@ -230,6 +260,10 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
>>       pc->chip.ops = &rockchip_pwm_ops;
>>       pc->chip.base = -1;
>>       pc->chip.npwm = 1;
>> +     if (pc->data->has_invert) {
>
> There should be a blank line between the above two.

Done.

[PATCH v3 2/4] pwm: rockchip: Allow polarity invert on rk3288

[Dmitry Torokhov]

On August 20, 2014 1:54:11 PM CDT, Doug Anderson <dianders@chromium.org> wrote:
>On Wed, Aug 20, 2014 at 3:04 AM, Thierry Reding
><thierry.reding@gmail.com> wrote:
>> On Tue, Aug 19, 2014 at 09:07:54AM -0700, Doug Anderson wrote:
>>> The rk3288 has the ability to invert 
>>> +     struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
>>> +
>>> +     if (!pc->data->has_invert)
>>> +             return -ENOSYS;
>>> +

At the kernel summit hpa also mentioned that ENOSYS should only be used for missing syscalls. Not sure what error code would suit better here though...


Thanks.

-- 
Dmitry

[PATCH v3 2/4] pwm: rockchip: Allow polarity invert on rk3288

[Doug Anderson]

Dmitry,

On Wed, Aug 20, 2014 at 12:29 PM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> On August 20, 2014 1:54:11 PM CDT, Doug Anderson <dianders@chromium.org> wrote:
>>On Wed, Aug 20, 2014 at 3:04 AM, Thierry Reding
>><thierry.reding@gmail.com> wrote:
>>> On Tue, Aug 19, 2014 at 09:07:54AM -0700, Doug Anderson wrote:
>>>> The rk3288 has the ability to invert
>>>> +     struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
>>>> +
>>>> +     if (!pc->data->has_invert)
>>>> +             return -ENOSYS;
>>>> +
>
> At the kernel summit hpa also mentioned that ENOSYS should only be used for missing syscalls. Not sure what error code would suit better here though...

Luckily this code is gone now.  See v4 of the series.  ;)

-Doug

[PATCH v3 2/4] pwm: rockchip: Allow polarity invert on rk3288

[Thierry Reding]

On Wed, Aug 20, 2014 at 02:29:17PM -0500, Dmitry Torokhov wrote:
> On August 20, 2014 1:54:11 PM CDT, Doug Anderson <dianders@chromium.org> wrote:
> >On Wed, Aug 20, 2014 at 3:04 AM, Thierry Reding
> ><thierry.reding@gmail.com> wrote:
> >> On Tue, Aug 19, 2014 at 09:07:54AM -0700, Doug Anderson wrote:
> >>> The rk3288 has the ability to invert 
> >>> +     struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
> >>> +
> >>> +     if (!pc->data->has_invert)
> >>> +             return -ENOSYS;
> >>> +
> 
> At the kernel summit hpa also mentioned that ENOSYS should only be
> used for missing syscalls. Not sure what error code would suit better
> here though...

I'd be interested in the rationale why ENOSYS shouldn't be used within
the kernel. As long as it doesn't leak to userspace where it could
possibly confuse applications I don't see any harm in using it.

Thierry
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[PATCH v3 3/4] ARM: dts: Add main PWM info to rk3288

[Doug Anderson]

This adds the PWM info (other than the VOP PWM) to the main rk3288
dtsi file.

Signed-off-by: Caesar Wang <caesar.wang@rock-chips.com>
Signed-off-by: Doug Anderson <dianders@chromium.org>
---
Changes in v3: None
Changes in v2: None

 arch/arm/boot/dts/rk3288.dtsi | 68 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi
index 36be7bb..9c9d9c5 100644
--- a/arch/arm/boot/dts/rk3288.dtsi
+++ b/arch/arm/boot/dts/rk3288.dtsi
@@ -261,6 +261,50 @@
 		status = "disabled";
 	};
 
+	pwm0: pwm at ff680000 {
+		compatible = "rockchip,rk3288-pwm";
+		reg = <0xff680000 0x10>;
+		#pwm-cells = <3>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pwm0_pin>;
+		clocks = <&cru PCLK_PWM>;
+		clock-names = "pwm";
+		status = "disabled";
+	};
+
+	pwm1: pwm at ff680010 {
+		compatible = "rockchip,rk3288-pwm";
+		reg = <0xff680010 0x10>;
+		#pwm-cells = <3>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pwm1_pin>;
+		clocks = <&cru PCLK_PWM>;
+		clock-names = "pwm";
+		status = "disabled";
+	};
+
+	pwm2: pwm at ff680020 {
+		compatible = "rockchip,rk3288-pwm";
+		reg = <0xff680020 0x10>;
+		#pwm-cells = <3>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pwm2_pin>;
+		clocks = <&cru PCLK_PWM>;
+		clock-names = "pwm";
+		status = "disabled";
+	};
+
+	pwm3: pwm at ff680030 {
+		compatible = "rockchip,rk3288-pwm";
+		reg = <0xff680030 0x10>;
+		#pwm-cells = <2>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pwm3_pin>;
+		clocks = <&cru PCLK_PWM>;
+		clock-names = "pwm";
+		status = "disabled";
+	};
+
 	pmu: power-management at ff730000 {
 		compatible = "rockchip,rk3288-pmu", "syscon";
 		reg = <0xff730000 0x100>;
@@ -611,5 +655,29 @@
 				rockchip,pins = <5 15 3 &pcfg_pull_none>;
 			};
 		};
+
+		pwm0 {
+			pwm0_pin: pwm0-pin {
+				rockchip,pins = <7 0 RK_FUNC_1 &pcfg_pull_none>;
+			};
+		};
+
+		pwm1 {
+			pwm1_pin: pwm1-pin {
+				rockchip,pins = <7 1 RK_FUNC_1 &pcfg_pull_none>;
+			};
+		};
+
+		pwm2 {
+			pwm2_pin: pwm2-pin {
+				rockchip,pins = <7 22 RK_FUNC_3 &pcfg_pull_none>;
+			};
+		};
+
+		pwm3 {
+			pwm3_pin: pwm3-pin {
+				rockchip,pins = <7 23 RK_FUNC_3 &pcfg_pull_none>;
+			};
+		};
 	};
 };
-- 
2.1.0.rc2.206.gedb03e5

[PATCH v3 4/4] ARM: dts: Enable PWM backlight on rk3288-EVB

[Doug Anderson]

PWM0 is the PWM associated with the LCD backlight.  Enable it.

Signed-off-by: Doug Anderson <dianders@chromium.org>
---
Changes in v3:
- Fix space to tab in 2 places in DTS.
- Make sure PWM is upper case in prose.

Changes in v2: None

 arch/arm/boot/dts/rk3288-evb.dtsi | 53 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/arch/arm/boot/dts/rk3288-evb.dtsi b/arch/arm/boot/dts/rk3288-evb.dtsi
index 2964370..98b69d0 100644
--- a/arch/arm/boot/dts/rk3288-evb.dtsi
+++ b/arch/arm/boot/dts/rk3288-evb.dtsi
@@ -10,6 +10,7 @@
  * GNU General Public License for more details.
  */
 
+#include <dt-bindings/pwm/pwm.h>
 #include "rk3288.dtsi"
 
 / {
@@ -17,6 +18,48 @@
 		reg = <0x0 0x80000000>;
 	};
 
+	backlight {
+		compatible = "pwm-backlight";
+		brightness-levels = <
+			  0   1   2   3   4   5   6   7
+			  8   9  10  11  12  13  14  15
+			 16  17  18  19  20  21  22  23
+			 24  25  26  27  28  29  30  31
+			 32  33  34  35  36  37  38  39
+			 40  41  42  43  44  45  46  47
+			 48  49  50  51  52  53  54  55
+			 56  57  58  59  60  61  62  63
+			 64  65  66  67  68  69  70  71
+			 72  73  74  75  76  77  78  79
+			 80  81  82  83  84  85  86  87
+			 88  89  90  91  92  93  94  95
+			 96  97  98  99 100 101 102 103
+			104 105 106 107 108 109 110 111
+			112 113 114 115 116 117 118 119
+			120 121 122 123 124 125 126 127
+			128 129 130 131 132 133 134 135
+			136 137 138 139 140 141 142 143
+			144 145 146 147 148 149 150 151
+			152 153 154 155 156 157 158 159
+			160 161 162 163 164 165 166 167
+			168 169 170 171 172 173 174 175
+			176 177 178 179 180 181 182 183
+			184 185 186 187 188 189 190 191
+			192 193 194 195 196 197 198 199
+			200 201 202 203 204 205 206 207
+			208 209 210 211 212 213 214 215
+			216 217 218 219 220 221 222 223
+			224 225 226 227 228 229 230 231
+			232 233 234 235 236 237 238 239
+			240 241 242 243 244 245 246 247
+			248 249 250 251 252 253 254 255>;
+		default-brightness-level = <128>;
+		enable-gpios = <&gpio7 2 GPIO_ACTIVE_HIGH>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&bl_en>;
+		pwms = <&pwm0 0 1000000 PWM_POLARITY_INVERTED>;
+	};
+
 	gpio-keys {
 		compatible = "gpio-keys";
 		#address-cells = <1>;
@@ -81,6 +124,10 @@
 	status = "okay";
 };
 
+&pwm0 {
+	status = "okay";
+};
+
 &uart0 {
 	status = "okay";
 };
@@ -102,6 +149,12 @@
 };
 
 &pinctrl {
+	backlight {
+		bl_en: bl-en {
+			rockchip,pins = <7 2 RK_FUNC_GPIO &pcfg_pull_none>;
+		};
+	};
+
 	buttons {
 		pwrbtn: pwrbtn {
 			rockchip,pins = <0 5 RK_FUNC_GPIO &pcfg_pull_up>;
-- 
2.1.0.rc2.206.gedb03e5