Re: [PATCH 1/3] mfd: cros-ec: Add functions to read mapped memory

[Guenter Roeck]

On 04/13/2017 03:53 PM, Moritz Fischer wrote:

Hi Guenter,

On Thu, Apr 13, 2017 at 2:03 PM, Guenter Roeck  wrote:

On Fri, Apr 07, 2017 at 03:00:08PM -0700, Moritz Fischer wrote:

From: Moritz Fischer 

The ChromeOS EC has mapped memory regions where things like temperature
sensors and fan speed are stored. Provide access to those from the
cros-ec mfd device.



Turns out struct cros_ec_device already provides a cmd_readmem callback,
which is widely used by other drivers. Why don't you just use it ?


This is only actually set by the lpc version of the cros_ec. I2C and
SPI connected ECs


Hmm - weird. I thought I saw it implemented for those, but I must have been
struck by lightning or something. Let me check with Gwendal to see how
this (ie its use from iio) is supposed to work on non-LPC systems.

Guenter


emulate it. I can most certainly hook it up in the (spi,i2c) drivers,
but the implementation
for SPI and I2C needs to live somewhere. drivers/platform/chrome/cros_ec_proto.c
seemed to be a good place.

Thanks for the feedback!

Moritz
--
To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html



--
To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 1/3] mfd: cros-ec: Add functions to read mapped memory

[Guenter Roeck]

On Fri, Apr 07, 2017 at 03:00:08PM -0700, Moritz Fischer wrote:
> From: Moritz Fischer 
> 
> The ChromeOS EC has mapped memory regions where things like temperature
> sensors and fan speed are stored. Provide access to those from the
> cros-ec mfd device.
> 

Turns out struct cros_ec_device already provides a cmd_readmem callback,
which is widely used by other drivers. Why don't you just use it ?

Thanks,
Guenter

> Signed-off-by: Moritz Fischer 
> ---
>  drivers/platform/chrome/cros_ec_proto.c | 55 
> +
>  include/linux/mfd/cros_ec.h | 39 +++
>  2 files changed, 94 insertions(+)
> 
> diff --git a/drivers/platform/chrome/cros_ec_proto.c 
> b/drivers/platform/chrome/cros_ec_proto.c
> index ed5dee7..28063de 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -494,3 +494,58 @@ int cros_ec_get_next_event(struct cros_ec_device *ec_dev)
>   return get_keyboard_state_event(ec_dev);
>  }
>  EXPORT_SYMBOL(cros_ec_get_next_event);
> +
> +static int __cros_ec_read_mapped_mem(struct cros_ec_device *ec, uint8_t 
> offset,
> +  void *buf, size_t size)
> +{
> + int ret;
> + struct ec_params_read_memmap *params;
> + struct cros_ec_command *msg;
> +
> + msg = kzalloc(sizeof(*msg) + max(sizeof(*params), size), GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + msg->version = 0;
> + msg->command = EC_CMD_READ_MEMMAP;
> + msg->insize = size;
> + msg->outsize = sizeof(*params);
> +
> + params = (struct ec_params_read_memmap *)msg->data;
> + params->offset = offset;
> + params->size = size;
> +
> + ret = cros_ec_cmd_xfer(ec, msg);
> + if (ret < 0 || msg->result != EC_RES_SUCCESS) {
> + dev_warn(ec->dev, "cannot read mapped reg: %d/%d\n",
> +  ret, msg->result);
> + goto out_free;
> + }
> +
> + memcpy(buf, msg->data, size);
> +
> +out_free:
> + kfree(msg);
> + return ret;
> +}
> +
> +int cros_ec_read_mapped_mem32(struct cros_ec_device *ec, const uint8_t 
> offset,
> +   uint32_t *data)
> +{
> + return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem32);
> +
> +int cros_ec_read_mapped_mem16(struct cros_ec_device *ec, const uint8_t 
> offset,
> +   uint16_t *data)
> +{
> + return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem16);
> +
> +int cros_ec_read_mapped_mem8(struct cros_ec_device *ec, const uint8_t offset,
> +  uint8_t *data)
> +{
> + return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem8);
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index b3d04de..c2de878 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -190,6 +190,45 @@ struct cros_ec_dev {
>  };
>  
>  /**
> + * cros_ec_read_mapped_mem8 - Read mapped memory in the ChromeOS EC
> + *
> + * This can be called by drivers to access the mapped memory in the EC
> + *
> + * @ec_dev: Device to read from
> + * @offset: Offset to read
> + * @data: Return data
> + * @return: 0 if Ok, -ve on error
> + */
> +int cros_ec_read_mapped_mem8(struct cros_ec_device *ec, const uint8_t offset,
> +  uint8_t *data);
> +
> +/**
> + * cros_ec_read_mapped_mem16 - Read mapped memory in the ChromeOS EC
> + *
> + * This can be called by drivers to access the mapped memory in the EC
> + *
> + * @ec_dev: Device to read from
> + * @offset: Offset to read
> + * @data: Return data
> + * @return: 0 if Ok, -ve on error
> + */
> +int cros_ec_read_mapped_mem16(struct cros_ec_device *ec, const uint8_t 
> offset,
> +   uint16_t *data);
> +
> +/**
> + * cros_ec_read_mapped_mem32 - Read mapped memory in the ChromeOS EC
> + *
> + * This can be called by drivers to access the mapped memory in the EC
> + *
> + * @ec_dev: Device to read from
> + * @offset: Offset to read
> + * @data: Return data
> + * @return: 0 if Ok, -ve on error
> + */
> +int cros_ec_read_mapped_mem32(struct cros_ec_device *ec, const uint8_t 
> offset,
> +   uint32_t *data);
> +
> +/**
>   * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
>   *
>   * This can be called by drivers to handle a suspend event.
> -- 
> 2.7.4
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 1/3] mfd: cros-ec: Add functions to read mapped memory

[Moritz Fischer]

On Sun, Apr 09, 2017 at 04:02:04PM -0700, Guenter Roeck wrote:
> On 04/07/2017 03:00 PM, Moritz Fischer wrote:
> > From: Moritz Fischer 
> >
> > The ChromeOS EC has mapped memory regions where things like temperature
> > sensors and fan speed are stored. Provide access to those from the
> > cros-ec mfd device.
> >
> > Signed-off-by: Moritz Fischer 
>
> I'll have to consult with others at Google if this is a good idea.
> Benson, can you comment ?

Well to my knowledge the only other way to get to it is the 'ectool'
from userland
via ioctl calls. The other option would be IIO ...
>
> > ---
> >  drivers/platform/chrome/cros_ec_proto.c | 55 
> > +
> >  include/linux/mfd/cros_ec.h | 39 +++
> >  2 files changed, 94 insertions(+)
> >
> > diff --git a/drivers/platform/chrome/cros_ec_proto.c 
> > b/drivers/platform/chrome/cros_ec_proto.c
> > index ed5dee7..28063de 100644
> > --- a/drivers/platform/chrome/cros_ec_proto.c
> > +++ b/drivers/platform/chrome/cros_ec_proto.c
> > @@ -494,3 +494,58 @@ int cros_ec_get_next_event(struct cros_ec_device 
> > *ec_dev)
> >   return get_keyboard_state_event(ec_dev);
> >  }
> >  EXPORT_SYMBOL(cros_ec_get_next_event);
> > +
> > +static int __cros_ec_read_mapped_mem(struct cros_ec_device *ec, uint8_t 
> > offset,
> > + void *buf, size_t size)
> > +{
> > + int ret;
> > + struct ec_params_read_memmap *params;
> > + struct cros_ec_command *msg;
> > +
> > + msg = kzalloc(sizeof(*msg) + max(sizeof(*params), size), GFP_KERNEL);
> > + if (!msg)
> > + return -ENOMEM;
> > +
>
> I don't think using kzalloc here makes much sense. It is well known
> that size is <= 4, so using a local buffer should not be a problem.

Good point, that was basically copy & paste from other cros-ec code ;-)
I'll fix this.

>
> > + msg->version = 0;
> > + msg->command = EC_CMD_READ_MEMMAP;
> > + msg->insize = size;
> > + msg->outsize = sizeof(*params);
> > +
> > + params = (struct ec_params_read_memmap *)msg->data;
> > + params->offset = offset;
> > + params->size = size;
> > +
> > + ret = cros_ec_cmd_xfer(ec, msg);
> > + if (ret < 0 || msg->result != EC_RES_SUCCESS) {
>
> cros_ec_cmd_xfer_status() was introduced to be able to avoid the second check.
>

Alright, cool. Will fix this.

> > + dev_warn(ec->dev, "cannot read mapped reg: %d/%d\n",
> > + ret, msg->result);
> > + goto out_free;
> > + }
> > +
> > + memcpy(buf, msg->data, size);
> > +
> > +out_free:
> > + kfree(msg);
> > + return ret;
> > +}
> > +
> > +int cros_ec_read_mapped_mem32(struct cros_ec_device *ec, const uint8_t 
> > offset,
> > +  uint32_t *data)
> > +{
> > + return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
> > +}
> > +EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem32);
> > +
> > +int cros_ec_read_mapped_mem16(struct cros_ec_device *ec, const uint8_t 
> > offset,
> > +  uint16_t *data)
> > +{
> > + return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
> > +}
> > +EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem16);
> > +
>
> Either case, this assumes that EC endianness matches host endianness. I don't
> think we can just assume that this is the case.

Huh, yeah. Will need to figure out how to detect the EC endianness in
that case.

>
> > +int cros_ec_read_mapped_mem8(struct cros_ec_device *ec, const uint8_t 
> > offset,
> > + uint8_t *data)
> > +{
> > + return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
> > +}
> > +EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem8);
> > diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> > index b3d04de..c2de878 100644
> > --- a/include/linux/mfd/cros_ec.h
> > +++ b/include/linux/mfd/cros_ec.h
> > @@ -190,6 +190,45 @@ struct cros_ec_dev {
> >  };
> >
> >  /**
> > + * cros_ec_read_mapped_mem8 - Read mapped memory in the ChromeOS EC
> > + *
> > + * This can be called by drivers to access the mapped memory in the EC
> > + *
> > + * @ec_dev: Device to read from
> > + * @offset: Offset to read
> > + * @data: Return data
> > + * @return: 0 if Ok, -ve on error
> > + */
> > +int cros_ec_read_mapped_mem8(struct cros_ec_device *ec, const uint8_t 
> > offset,
> > + uint8_t *data);
> > +
> > +/**
> > + * cros_ec_read_mapped_mem16 - Read mapped memory in the ChromeOS EC
> > + *
> > + * This can be called by drivers to access the mapped memory in the EC
> > + *
> > + * @ec_dev: Device to read from
> > + * @offset: Offset to read
> > + * @data: Return data
> > + * @return: 0 if Ok, -ve on error
> > + */
> > +int cros_ec_read_mapped_mem16(struct cros_ec_device *ec, const uint8_t 
> > offset,
> > +  uint16_t *data);
> > +
> > +/**
> > + * cros_ec_read_mapped_mem32 - Read mapped memory in the ChromeOS EC
> > + *
> > + * This can be called by drivers to access the mapped memory in the EC
> > + *
> > + * @ec_dev: Device to read from
> > + * @offset: Offset to read
> > + * @data: Return data
> > + * @return: 0 if Ok, -ve on error
> > + */
> > +int 

Re: [PATCH 1/3] mfd: cros-ec: Add functions to read mapped memory

[Guenter Roeck]

On 04/07/2017 03:00 PM, Moritz Fischer wrote:

From: Moritz Fischer 

The ChromeOS EC has mapped memory regions where things like temperature
sensors and fan speed are stored. Provide access to those from the
cros-ec mfd device.

Signed-off-by: Moritz Fischer 


I'll have to consult with others at Google if this is a good idea.
Benson, can you comment ?


---
 drivers/platform/chrome/cros_ec_proto.c | 55 +
 include/linux/mfd/cros_ec.h | 39 +++
 2 files changed, 94 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_proto.c 
b/drivers/platform/chrome/cros_ec_proto.c
index ed5dee7..28063de 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -494,3 +494,58 @@ int cros_ec_get_next_event(struct cros_ec_device *ec_dev)
return get_keyboard_state_event(ec_dev);
 }
 EXPORT_SYMBOL(cros_ec_get_next_event);
+
+static int __cros_ec_read_mapped_mem(struct cros_ec_device *ec, uint8_t offset,
+void *buf, size_t size)
+{
+   int ret;
+   struct ec_params_read_memmap *params;
+   struct cros_ec_command *msg;
+
+   msg = kzalloc(sizeof(*msg) + max(sizeof(*params), size), GFP_KERNEL);
+   if (!msg)
+   return -ENOMEM;
+


I don't think using kzalloc here makes much sense. It is well known
that size is <= 4, so using a local buffer should not be a problem.


+   msg->version = 0;
+   msg->command = EC_CMD_READ_MEMMAP;
+   msg->insize = size;
+   msg->outsize = sizeof(*params);
+
+   params = (struct ec_params_read_memmap *)msg->data;
+   params->offset = offset;
+   params->size = size;
+
+   ret = cros_ec_cmd_xfer(ec, msg);
+   if (ret < 0 || msg->result != EC_RES_SUCCESS) {


cros_ec_cmd_xfer_status() was introduced to be able to avoid the second check.


+   dev_warn(ec->dev, "cannot read mapped reg: %d/%d\n",
+ret, msg->result);
+   goto out_free;
+   }
+
+   memcpy(buf, msg->data, size);
+
+out_free:
+   kfree(msg);
+   return ret;
+}
+
+int cros_ec_read_mapped_mem32(struct cros_ec_device *ec, const uint8_t offset,
+ uint32_t *data)
+{
+   return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
+}
+EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem32);
+
+int cros_ec_read_mapped_mem16(struct cros_ec_device *ec, const uint8_t offset,
+ uint16_t *data)
+{
+   return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
+}
+EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem16);
+


Either case, this assumes that EC endianness matches host endianness. I don't
think we can just assume that this is the case.


+int cros_ec_read_mapped_mem8(struct cros_ec_device *ec, const uint8_t offset,
+uint8_t *data)
+{
+   return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
+}
+EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem8);
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index b3d04de..c2de878 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -190,6 +190,45 @@ struct cros_ec_dev {
 };

 /**
+ * cros_ec_read_mapped_mem8 - Read mapped memory in the ChromeOS EC
+ *
+ * This can be called by drivers to access the mapped memory in the EC
+ *
+ * @ec_dev: Device to read from
+ * @offset: Offset to read
+ * @data: Return data
+ * @return: 0 if Ok, -ve on error
+ */
+int cros_ec_read_mapped_mem8(struct cros_ec_device *ec, const uint8_t offset,
+uint8_t *data);
+
+/**
+ * cros_ec_read_mapped_mem16 - Read mapped memory in the ChromeOS EC
+ *
+ * This can be called by drivers to access the mapped memory in the EC
+ *
+ * @ec_dev: Device to read from
+ * @offset: Offset to read
+ * @data: Return data
+ * @return: 0 if Ok, -ve on error
+ */
+int cros_ec_read_mapped_mem16(struct cros_ec_device *ec, const uint8_t offset,
+ uint16_t *data);
+
+/**
+ * cros_ec_read_mapped_mem32 - Read mapped memory in the ChromeOS EC
+ *
+ * This can be called by drivers to access the mapped memory in the EC
+ *
+ * @ec_dev: Device to read from
+ * @offset: Offset to read
+ * @data: Return data
+ * @return: 0 if Ok, -ve on error
+ */
+int cros_ec_read_mapped_mem32(struct cros_ec_device *ec, const uint8_t offset,
+ uint32_t *data);
+
+/**
  * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
  *
  * This can be called by drivers to handle a suspend event.



--
To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH 1/3] mfd: cros-ec: Add functions to read mapped memory

[Moritz Fischer]

From: Moritz Fischer 

The ChromeOS EC has mapped memory regions where things like temperature
sensors and fan speed are stored. Provide access to those from the
cros-ec mfd device.

Signed-off-by: Moritz Fischer 
---
 drivers/platform/chrome/cros_ec_proto.c | 55 +
 include/linux/mfd/cros_ec.h | 39 +++
 2 files changed, 94 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_proto.c 
b/drivers/platform/chrome/cros_ec_proto.c
index ed5dee7..28063de 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -494,3 +494,58 @@ int cros_ec_get_next_event(struct cros_ec_device *ec_dev)
return get_keyboard_state_event(ec_dev);
 }
 EXPORT_SYMBOL(cros_ec_get_next_event);
+
+static int __cros_ec_read_mapped_mem(struct cros_ec_device *ec, uint8_t offset,
+void *buf, size_t size)
+{
+   int ret;
+   struct ec_params_read_memmap *params;
+   struct cros_ec_command *msg;
+
+   msg = kzalloc(sizeof(*msg) + max(sizeof(*params), size), GFP_KERNEL);
+   if (!msg)
+   return -ENOMEM;
+
+   msg->version = 0;
+   msg->command = EC_CMD_READ_MEMMAP;
+   msg->insize = size;
+   msg->outsize = sizeof(*params);
+
+   params = (struct ec_params_read_memmap *)msg->data;
+   params->offset = offset;
+   params->size = size;
+
+   ret = cros_ec_cmd_xfer(ec, msg);
+   if (ret < 0 || msg->result != EC_RES_SUCCESS) {
+   dev_warn(ec->dev, "cannot read mapped reg: %d/%d\n",
+ret, msg->result);
+   goto out_free;
+   }
+
+   memcpy(buf, msg->data, size);
+
+out_free:
+   kfree(msg);
+   return ret;
+}
+
+int cros_ec_read_mapped_mem32(struct cros_ec_device *ec, const uint8_t offset,
+ uint32_t *data)
+{
+   return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
+}
+EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem32);
+
+int cros_ec_read_mapped_mem16(struct cros_ec_device *ec, const uint8_t offset,
+ uint16_t *data)
+{
+   return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
+}
+EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem16);
+
+int cros_ec_read_mapped_mem8(struct cros_ec_device *ec, const uint8_t offset,
+uint8_t *data)
+{
+   return __cros_ec_read_mapped_mem(ec, offset, data, sizeof(*data));
+}
+EXPORT_SYMBOL_GPL(cros_ec_read_mapped_mem8);
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index b3d04de..c2de878 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -190,6 +190,45 @@ struct cros_ec_dev {
 };
 
 /**
+ * cros_ec_read_mapped_mem8 - Read mapped memory in the ChromeOS EC
+ *
+ * This can be called by drivers to access the mapped memory in the EC
+ *
+ * @ec_dev: Device to read from
+ * @offset: Offset to read
+ * @data: Return data
+ * @return: 0 if Ok, -ve on error
+ */
+int cros_ec_read_mapped_mem8(struct cros_ec_device *ec, const uint8_t offset,
+uint8_t *data);
+
+/**
+ * cros_ec_read_mapped_mem16 - Read mapped memory in the ChromeOS EC
+ *
+ * This can be called by drivers to access the mapped memory in the EC
+ *
+ * @ec_dev: Device to read from
+ * @offset: Offset to read
+ * @data: Return data
+ * @return: 0 if Ok, -ve on error
+ */
+int cros_ec_read_mapped_mem16(struct cros_ec_device *ec, const uint8_t offset,
+ uint16_t *data);
+
+/**
+ * cros_ec_read_mapped_mem32 - Read mapped memory in the ChromeOS EC
+ *
+ * This can be called by drivers to access the mapped memory in the EC
+ *
+ * @ec_dev: Device to read from
+ * @offset: Offset to read
+ * @data: Return data
+ * @return: 0 if Ok, -ve on error
+ */
+int cros_ec_read_mapped_mem32(struct cros_ec_device *ec, const uint8_t offset,
+ uint32_t *data);
+
+/**
  * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
  *
  * This can be called by drivers to handle a suspend event.
-- 
2.7.4

--
To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html