Re: [PATCH] Input: synaptics-rmi4: Support regulator supplies

Andrew Duggan <aduggan@xxxxxxxxxxxxx> · Thu, 31 Mar 2016 18:47:49 -0700

On 03/31/2016 12:14 PM, Bjorn Andersson wrote:
On Thu 31 Mar 11:19 PDT 2016, Dmitry Torokhov wrote:

Hi Bjorn,

On Wed, Mar 30, 2016 at 09:57:29AM -0700, Bjorn Andersson wrote:
From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>

Support the two supplies - vdd and vio - to make it possible to control
power to the Synaptics chip.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---
  .../devicetree/bindings/input/rmi4/rmi_i2c.txt     |  7 ++++
  drivers/input/rmi4/rmi_i2c.c                       | 45 ++++++++++++++++++++++
Would not we need pretty much the same changes for SPI devices? Can this
be done in core?

Yes, I believe it needs the exact same steps.

I did a initial quick hack on v1 of the patchset and back then it was
possible, when I rebased it a few weeks back I kept ending up in getting
interrupts with the power off.

Looking at the code this is likely because in the resume paths the IRQ
is enabled before we jump to rmi_driver_resume(), so putting this in the
core I ended up calling rmi_process_interrupt_requests() before powering
up the chip.

Actually, I don't think the irq needs to be enabled before calling 
rmi_driver_resume(). Typically, the functions are just reading and 
writing to registers and do not need to handle interrupts. We could 
probably call to rmi_driver_resume() before enabling the irq. I can 
double check that there are not any exceptions to this.

I have also considered adding a power callback to the core so that the 
transport drivers can set the power independently of suspend and resume. 
One example would be to shut off power to a touchpad if a mouse is 
connected. If we do need to have the irq enabled before calling 
rmi_driver_resume() we could still move regulator support to the core 
and call the power callback from the transport drivers.

Andrew

I assume it's done this way to allow incoming interrupts while functions
are being resumed. Andrew, can you comment on this?

Regards,
Bjorn

Thanks.

  2 files changed, 52 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/rmi4/rmi_i2c.txt b/Documentation/devicetree/bindings/input/rmi4/rmi_i2c.txt
index 95fa715c6046..a8c31f40f816 100644
--- a/Documentation/devicetree/bindings/input/rmi4/rmi_i2c.txt
+++ b/Documentation/devicetree/bindings/input/rmi4/rmi_i2c.txt
@@ -22,6 +22,13 @@ See Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
  - syna,reset-delay-ms: The number of milliseconds to wait after resetting the
  			device.
  
+- vdd-supply: VDD power supply.
+See Documentation/devicetree/bindings/regulator/regulator.txt
+
+- vio-supply: VIO power supply
+See Documentation/devicetree/bindings/regulator/regulator.txt
+
+
  Function Parameters:
  Parameters specific to RMI functions are contained in child nodes of the rmi device
   node. Documentation for the parameters of each function can be found in:
diff --git a/drivers/input/rmi4/rmi_i2c.c b/drivers/input/rmi4/rmi_i2c.c
index a96a326b53bd..a8c794daba04 100644
--- a/drivers/input/rmi4/rmi_i2c.c
+++ b/drivers/input/rmi4/rmi_i2c.c
@@ -11,6 +11,8 @@
  #include <linux/rmi.h>
  #include <linux/irq.h>
  #include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/regulator/consumer.h>
  #include "rmi_driver.h"
  
  #define BUFFER_SIZE_INCREMENT 32
@@ -37,6 +39,8 @@ struct rmi_i2c_xport {
  
  	u8 *tx_buf;
  	size_t tx_buf_size;
+
+	struct regulator_bulk_data supplies[2];
  };
  
  #define RMI_PAGE_SELECT_REGISTER 0xff
@@ -246,6 +250,22 @@ static int rmi_i2c_probe(struct i2c_client *client,
  		return -ENODEV;
  	}
  
+	rmi_i2c->supplies[0].supply = "vdd";
+	rmi_i2c->supplies[1].supply = "vio";
+	retval = devm_regulator_bulk_get(&client->dev,
+					 ARRAY_SIZE(rmi_i2c->supplies),
+					 rmi_i2c->supplies);
+	if (retval < 0)
+		return retval;
+
+	retval = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
+				       rmi_i2c->supplies);
+	if (retval < 0)
+		return retval;
+
+	/* Allow the firmware to get ready */
+	msleep(10);
+
  	rmi_i2c->client = client;
  	mutex_init(&rmi_i2c->page_mutex);
  
@@ -286,6 +306,8 @@ static int rmi_i2c_remove(struct i2c_client *client)
  	struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
  
  	rmi_unregister_transport_device(&rmi_i2c->xport);
+	regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
+			       rmi_i2c->supplies);
  
  	return 0;
  }
@@ -308,6 +330,10 @@ static int rmi_i2c_suspend(struct device *dev)
  			dev_warn(dev, "Failed to enable irq for wake: %d\n",
  				ret);
  	}
+
+	regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
+			       rmi_i2c->supplies);
+
  	return ret;
  }
  
@@ -317,6 +343,14 @@ static int rmi_i2c_resume(struct device *dev)
  	struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
  	int ret;
  
+	ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
+				    rmi_i2c->supplies);
+	if (ret)
+		return ret;
+
+	/* Allow the firmware to get ready */
+	msleep(10);
+
  	enable_irq(rmi_i2c->irq);
  	if (device_may_wakeup(&client->dev)) {
  		ret = disable_irq_wake(rmi_i2c->irq);
@@ -346,6 +380,9 @@ static int rmi_i2c_runtime_suspend(struct device *dev)
  
  	disable_irq(rmi_i2c->irq);
  
+	regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
+			       rmi_i2c->supplies);
+
  	return 0;
  }
  
@@ -355,6 +392,14 @@ static int rmi_i2c_runtime_resume(struct device *dev)
  	struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
  	int ret;
  
+	ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
+				    rmi_i2c->supplies);
+	if (ret)
+		return ret;
+
+	/* Allow the firmware to get ready */
+	msleep(10);
+
  	enable_irq(rmi_i2c->irq);
  
  	ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev);
--
2.5.0

--
Dmitry

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