[PATCH v4 0/5] LogiCVC mfd and GPIO support

[PATCH v4 0/5] LogiCVC mfd and GPIO support

[Paul Kocialkowski]

This series introduces support for the LogiCVC GPIO block to the syscon GPIO
driver, with dt bindings documentation also including the top-level mfd
component.

Changes since v3:
- Added collected tags;
- Kept syscon_gpio_data set function pointer line intact;
- Grouped declarations in a single line as requested.

Changes since v2:
- Fixed dt schema examples.

Changes since v1:
- Converted dt bindings documentation to dt schemas;
- Used BIT macro and removed version from structure name;
- Improved documentation example with gpio-line-names;
- Added vendor prefix to dt bindings;
- Added mfd component dt bindings documentation.

Cheers,

Paul

Paul Kocialkowski (5):
  dt-bindings: Add Xylon vendor prefix
  dt-bindings: mfd: Document the Xylon LogiCVC multi-function device
  gpio: syscon: Add support for a custom get operation
  dt-bindings: gpio: Document the Xylon LogiCVC GPIO controller
  gpio: syscon: Add support for the Xylon LogiCVC GPIOs

 .../bindings/gpio/xylon,logicvc-gpio.yaml     | 69 +++++++++++++++++++
 .../bindings/mfd/xylon,logicvc.yaml           | 50 ++++++++++++++
 .../devicetree/bindings/vendor-prefixes.yaml  |  2 +
 drivers/gpio/gpio-syscon.c                    | 68 +++++++++++++++++-
 4 files changed, 188 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/gpio/xylon,logicvc-gpio.yaml
 create mode 100644 Documentation/devicetree/bindings/mfd/xylon,logicvc.yaml

-- 
2.24.0

[PATCH v4 1/5] dt-bindings: Add Xylon vendor prefix

[Paul Kocialkowski]

Xylon is an electronics company that produces FPGA hardware block designs
optimized for Xilinx FPGAs.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index fd6fa07c45b8..e7f7bf7c1c22 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -1056,6 +1056,8 @@ patternProperties:
     description: Xilinx
   "^xunlong,.*":
     description: Shenzhen Xunlong Software CO.,Limited
+  "^xylon,.*":
+    description: Xylon
   "^yones-toptech,.*":
     description: Yones Toptech Co., Ltd.
   "^ysoft,.*":
-- 
2.24.0

[PATCH v4 2/5] dt-bindings: mfd: Document the Xylon LogiCVC multi-function device

[Paul Kocialkowski]

The LogiCVC is a display engine which also exposes GPIO functionality.
For this reason, it is described as a multi-function device that is expected
to provide register access to its children nodes for gpio and display.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/mfd/xylon,logicvc.yaml           | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/xylon,logicvc.yaml

diff --git a/Documentation/devicetree/bindings/mfd/xylon,logicvc.yaml b/Documentation/devicetree/bindings/mfd/xylon,logicvc.yaml
new file mode 100644
index 000000000000..abc9937506e0
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/xylon,logicvc.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2019 Bootlin
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/mfd/xylon,logicvc.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Xylon LogiCVC multi-function device
+
+maintainers:
+  - Paul Kocialkowski <paul.kocialkowski@bootlin.com>
+
+description: |
+  The LogiCVC is a display controller that also contains a GPIO controller.
+  As a result, a multi-function device is exposed as parent of the display
+  and GPIO blocks.
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - xylon,logicvc-3.02.a
+      - const: syscon
+      - const: simple-mfd
+
+  reg:
+    maxItems: 1
+
+select:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - xylon,logicvc-3.02.a
+
+  required:
+    - compatible
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    logicvc: logicvc@43c00000 {
+      compatible = "xylon,logicvc-3.02.a", "syscon", "simple-mfd";
+      reg = <0x43c00000 0x6000>;
+      #address-cells = <1>;
+      #size-cells = <1>;
+    };
-- 
2.24.0

[PATCH v4 3/5] gpio: syscon: Add support for a custom get operation

[Paul Kocialkowski]

Some drivers might need a custom get operation to match custom
behavior implemented in the set operation.

Add plumbing for supporting that.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
---
 drivers/gpio/gpio-syscon.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-syscon.c b/drivers/gpio/gpio-syscon.c
index 31f332074d7d..36136b7f3a3b 100644
--- a/drivers/gpio/gpio-syscon.c
+++ b/drivers/gpio/gpio-syscon.c
@@ -43,6 +43,7 @@ struct syscon_gpio_data {
 	unsigned int	bit_count;
 	unsigned int	dat_bit_offset;
 	unsigned int	dir_bit_offset;
+	int		(*get)(struct gpio_chip *chip, unsigned offset);
 	void		(*set)(struct gpio_chip *chip,
 			       unsigned offset, int value);
 };
@@ -252,7 +253,7 @@ static int syscon_gpio_probe(struct platform_device *pdev)
 	priv->chip.label = dev_name(dev);
 	priv->chip.base = -1;
 	priv->chip.ngpio = priv->data->bit_count;
-	priv->chip.get = syscon_gpio_get;
+	priv->chip.get = priv->data->get ? : syscon_gpio_get;
 	if (priv->data->flags & GPIO_SYSCON_FEAT_IN)
 		priv->chip.direction_input = syscon_gpio_dir_in;
 	if (priv->data->flags & GPIO_SYSCON_FEAT_OUT) {
-- 
2.24.0

[PATCH v4 4/5] dt-bindings: gpio: Document the Xylon LogiCVC GPIO controller

[Paul Kocialkowski]

The Xylon LogiCVC display controller exports some GPIOs, which are
exposed as a separate entity.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/gpio/xylon,logicvc-gpio.yaml     | 69 +++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/xylon,logicvc-gpio.yaml

diff --git a/Documentation/devicetree/bindings/gpio/xylon,logicvc-gpio.yaml b/Documentation/devicetree/bindings/gpio/xylon,logicvc-gpio.yaml
new file mode 100644
index 000000000000..d102888c1be7
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/xylon,logicvc-gpio.yaml
@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2019 Bootlin
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/gpio/xylon,logicvc-gpio.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Xylon LogiCVC GPIO controller
+
+maintainers:
+  - Paul Kocialkowski <paul.kocialkowski@bootlin.com>
+
+description: |
+  The LogiCVC GPIO describes the GPIO block included in the LogiCVC display
+  controller. These are meant to be used for controlling display-related
+  signals.
+
+  The controller exposes GPIOs from the display and power control registers,
+  which are mapped by the driver as follows:
+  - GPIO[4:0] (display control) mapped to index 0-4
+  - EN_BLIGHT (power control) mapped to index 5
+  - EN_VDD (power control) mapped to index 6
+  - EN_VEE (power control) mapped to index 7
+  - V_EN (power control) mapped to index 8
+
+properties:
+  $nodename:
+    pattern: "^gpio@[0-9a-f]+$"
+
+  compatible:
+    enum:
+      - xylon,logicvc-3.02.a-gpio
+
+  reg:
+    maxItems: 1
+
+  "#gpio-cells":
+    const: 2
+
+  gpio-controller: true
+
+  gpio-line-names:
+    minItems: 1
+    maxItems: 9
+
+required:
+  - compatible
+  - reg
+  - "#gpio-cells"
+  - gpio-controller
+
+examples:
+  - |
+    logicvc: logicvc@43c00000 {
+      compatible = "xylon,logicvc-3.02.a", "syscon", "simple-mfd";
+      reg = <0x43c00000 0x6000>;
+
+      #address-cells = <1>;
+      #size-cells = <1>;
+
+      logicvc_gpio: gpio@40 {
+        compatible = "xylon,logicvc-3.02.a-gpio";
+        reg = <0x40 0x40>;
+        gpio-controller;
+        #gpio-cells = <2>;
+        gpio-line-names = "GPIO0", "GPIO1", "GPIO2", "GPIO3", "GPIO4",
+               "EN_BLIGHT", "EN_VDD", "EN_VEE", "V_EN";
+      };
+    };
-- 
2.24.0

[PATCH v4 5/5] gpio: syscon: Add support for the Xylon LogiCVC GPIOs

[Paul Kocialkowski]

The LogiCVC display hardware block comes with GPIO capabilities
that must be exposed separately from the main driver (as GPIOs) for
use with regulators and panels. A syscon is used to share the same
regmap across the two drivers.

Since the GPIO capabilities are pretty simple, add them to the syscon
GPIO driver.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
---
 drivers/gpio/gpio-syscon.c | 65 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/drivers/gpio/gpio-syscon.c b/drivers/gpio/gpio-syscon.c
index 36136b7f3a3b..cf1127f81824 100644
--- a/drivers/gpio/gpio-syscon.c
+++ b/drivers/gpio/gpio-syscon.c
@@ -190,6 +190,67 @@ static const struct syscon_gpio_data keystone_dsp_gpio = {
 	.set		= keystone_gpio_set,
 };
 
+#define LOGICVC_CTRL_REG		0x40
+#define LOGICVC_CTRL_GPIO_SHIFT		11
+#define LOGICVC_CTRL_GPIO_BITS		5
+
+#define LOGICVC_POWER_CTRL_REG		0x78
+#define LOGICVC_POWER_CTRL_GPIO_SHIFT	0
+#define LOGICVC_POWER_CTRL_GPIO_BITS	4
+
+static void logicvc_gpio_offset(struct syscon_gpio_priv *priv,
+				unsigned offset, unsigned int *reg,
+				unsigned int *bit)
+{
+	if (offset >= LOGICVC_CTRL_GPIO_BITS) {
+		*reg = LOGICVC_POWER_CTRL_REG;
+
+		/* To the (virtual) power ctrl offset. */
+		offset -= LOGICVC_CTRL_GPIO_BITS;
+		/* To the actual bit offset in reg. */
+		offset += LOGICVC_POWER_CTRL_GPIO_SHIFT;
+	} else {
+		*reg = LOGICVC_CTRL_REG;
+
+		/* To the actual bit offset in reg. */
+		offset += LOGICVC_CTRL_GPIO_SHIFT;
+	}
+
+	*bit = BIT(offset);
+}
+
+static int logicvc_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
+	unsigned int reg, bit, value;
+	int ret;
+
+	logicvc_gpio_offset(priv, offset, &reg, &bit);
+
+	ret = regmap_read(priv->syscon, reg, &value);
+	if (ret)
+		return ret;
+
+	return !!(value & bit);
+}
+
+static void logicvc_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+	struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
+	unsigned int reg, bit;
+
+	logicvc_gpio_offset(priv, offset, &reg, &bit);
+
+	regmap_update_bits(priv->syscon, reg, bit, val ? bit : 0);
+}
+
+static const struct syscon_gpio_data logicvc_gpio = {
+	.flags		= GPIO_SYSCON_FEAT_OUT,
+	.bit_count	= LOGICVC_CTRL_GPIO_BITS + LOGICVC_POWER_CTRL_GPIO_BITS,
+	.get		= logicvc_gpio_get,
+	.set		= logicvc_gpio_set,
+};
+
 static const struct of_device_id syscon_gpio_ids[] = {
 	{
 		.compatible	= "cirrus,ep7209-mctrl-gpio",
@@ -203,6 +264,10 @@ static const struct of_device_id syscon_gpio_ids[] = {
 		.compatible	= "rockchip,rk3328-grf-gpio",
 		.data		= &rockchip_rk3328_gpio_mute,
 	},
+	{
+		.compatible	= "xylon,logicvc-3.02.a-gpio",
+		.data		= &logicvc_gpio,
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, syscon_gpio_ids);
-- 
2.24.0

Re: [PATCH v4 5/5] gpio: syscon: Add support for the Xylon LogiCVC GPIOs

[Linus Walleij]

Hi Paul,

thanks for your patch!

On Thu, Nov 28, 2019 at 4:54 PM Paul Kocialkowski
<paul.kocialkowski@bootlin.com> wrote:

> The LogiCVC display hardware block comes with GPIO capabilities
> that must be exposed separately from the main driver (as GPIOs) for
> use with regulators and panels. A syscon is used to share the same
> regmap across the two drivers.
>
> Since the GPIO capabilities are pretty simple, add them to the syscon
> GPIO driver.
>
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
(...)
> +#define LOGICVC_CTRL_REG               0x40
> +#define LOGICVC_CTRL_GPIO_SHIFT                11
> +#define LOGICVC_CTRL_GPIO_BITS         5
> +
> +#define LOGICVC_POWER_CTRL_REG         0x78
> +#define LOGICVC_POWER_CTRL_GPIO_SHIFT  0
> +#define LOGICVC_POWER_CTRL_GPIO_BITS   4
> +
> +static void logicvc_gpio_offset(struct syscon_gpio_priv *priv,
> +                               unsigned offset, unsigned int *reg,
> +                               unsigned int *bit)
> +{
> +       if (offset >= LOGICVC_CTRL_GPIO_BITS) {
> +               *reg = LOGICVC_POWER_CTRL_REG;
> +
> +               /* To the (virtual) power ctrl offset. */
> +               offset -= LOGICVC_CTRL_GPIO_BITS;
> +               /* To the actual bit offset in reg. */
> +               offset += LOGICVC_POWER_CTRL_GPIO_SHIFT;
> +       } else {
> +               *reg = LOGICVC_CTRL_REG;
> +
> +               /* To the actual bit offset in reg. */
> +               offset += LOGICVC_CTRL_GPIO_SHIFT;
> +       }
> +
> +       *bit = BIT(offset);
> +}

The gpio-syscon.c is for simple syscons where the lines
you want to affect are nicely ordered in the registers.
It is intended to be generic.

This is kind of shoehorning a special case into the generic
code.

Isn't it more appropriate to create a specific driver for this
hardware?

Special get/set quirks for any possible quirky offset is
certainly not the way to go, if this should be supported
we need generic properties in struct syscon_gpio_data
to indicate the valid bits and offsets.

Yours,
Linus Walleij

Re: [PATCH v4 5/5] gpio: syscon: Add support for the Xylon LogiCVC GPIOs

[Paul Kocialkowski]

[-- Attachment #1: Type: text/plain, Size: 2781 bytes --]

Hi Linus,

On Fri 29 Nov 19, 10:24, Linus Walleij wrote:
> Hi Paul,
> 
> thanks for your patch!
> 
> On Thu, Nov 28, 2019 at 4:54 PM Paul Kocialkowski
> <paul.kocialkowski@bootlin.com> wrote:
> 
> > The LogiCVC display hardware block comes with GPIO capabilities
> > that must be exposed separately from the main driver (as GPIOs) for
> > use with regulators and panels. A syscon is used to share the same
> > regmap across the two drivers.
> >
> > Since the GPIO capabilities are pretty simple, add them to the syscon
> > GPIO driver.
> >
> > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> (...)
> > +#define LOGICVC_CTRL_REG               0x40
> > +#define LOGICVC_CTRL_GPIO_SHIFT                11
> > +#define LOGICVC_CTRL_GPIO_BITS         5
> > +
> > +#define LOGICVC_POWER_CTRL_REG         0x78
> > +#define LOGICVC_POWER_CTRL_GPIO_SHIFT  0
> > +#define LOGICVC_POWER_CTRL_GPIO_BITS   4
> > +
> > +static void logicvc_gpio_offset(struct syscon_gpio_priv *priv,
> > +                               unsigned offset, unsigned int *reg,
> > +                               unsigned int *bit)
> > +{
> > +       if (offset >= LOGICVC_CTRL_GPIO_BITS) {
> > +               *reg = LOGICVC_POWER_CTRL_REG;
> > +
> > +               /* To the (virtual) power ctrl offset. */
> > +               offset -= LOGICVC_CTRL_GPIO_BITS;
> > +               /* To the actual bit offset in reg. */
> > +               offset += LOGICVC_POWER_CTRL_GPIO_SHIFT;
> > +       } else {
> > +               *reg = LOGICVC_CTRL_REG;
> > +
> > +               /* To the actual bit offset in reg. */
> > +               offset += LOGICVC_CTRL_GPIO_SHIFT;
> > +       }
> > +
> > +       *bit = BIT(offset);
> > +}
> 
> The gpio-syscon.c is for simple syscons where the lines
> you want to affect are nicely ordered in the registers.
> It is intended to be generic.
> 
> This is kind of shoehorning a special case into the generic
> code.
> 
> Isn't it more appropriate to create a specific driver for this
> hardware?

Yes I'm fine with that too. Indeed the driver has custom set/get operations
that don't really fit well into generic code.

> Special get/set quirks for any possible quirky offset is
> certainly not the way to go, if this should be supported
> we need generic properties in struct syscon_gpio_data
> to indicate the valid bits and offsets.

I guess the rationale would be to define multiple possible bit offsets for
different ranges of GPIO offsets, but I don't think it would be very useful
outside of this case.

I'll probably craft a new version with a dedicated driver then.

Cheers,

Paul

-- 
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]