Re: [PATCH v3 6/7] mfd: cros_ec: Support multiple EC in a system

2015-05-28 Thread Javier Martinez Canillas 
Hello Lee,

Thanks a lot for your feedback.

On 05/27/2015 11:11 AM, Lee Jones wrote:
 On Fri, 22 May 2015, Javier Martinez Canillas wrote:
 
 From: Gwendal Grignou gwen...@chromium.org
 
 Chromebooks can have more than one Embedded Controller so the
 cros_ec device id has to be incremented for each EC registered.
 
 Add code to handle multiple EC. First ec found is cros-ec0,
 second cros-ec1 and so on.
 
 Add a new structure to represent multiple EC as different char
 devices (e.g: /dev/cros_ec, /dev/cros_pd). It connects to
 cros_ec_device and allows sysfs inferface for cros_pd.
 
 Also reduce number of allocated objects, make chromeos sysfs
 class object a static and add refcounting to prevent object
 deletion while command is in progress.
 
 Signed-off-by: Gwendal Grignou gwen...@chromium.org
 Reviewed-by: Dmitry Torokhov d...@chromium.org
 Signed-off-by: Javier Martinez Canillas javier.marti...@collabora.co.uk
 ---
 
 Changes since v2: None
 
 Changes since v1:
   - Squash patch that adds support to represent EC's as different
 char devices (e.g: /dev/cros_ec, /dev/cros_pd):
 https://chromium-review.googlesource.com/#/c/217297/
 Suggested by Gwendal Grignou
   - Use cros_ec instead of cros-ec in the subject line to be consistent.
 Suggested by Gwendal Grignou
 ---
  drivers/input/keyboard/cros_ec_keyb.c  |   2 +-
  drivers/mfd/cros_ec.c  |  66 +--
  drivers/mfd/cros_ec_i2c.c  |   1 -
  drivers/mfd/cros_ec_spi.c  |   1 -
  drivers/platform/chrome/cros_ec_dev.c  | 128 
 -
  drivers/platform/chrome/cros_ec_dev.h  |   7 --
  drivers/platform/chrome/cros_ec_lightbar.c |  75 +
  drivers/platform/chrome/cros_ec_lpc.c  |   1 -
  drivers/platform/chrome/cros_ec_sysfs.c|  48 +--
  include/linux/mfd/cros_ec.h|  44 --
  10 files changed, 247 insertions(+), 126 deletions(-)
 
 diff --git a/drivers/input/keyboard/cros_ec_keyb.c 
 b/drivers/input/keyboard/cros_ec_keyb.c
 index 974154a74505..b01966dc7eb3 100644
 --- a/drivers/input/keyboard/cros_ec_keyb.c
 +++ b/drivers/input/keyboard/cros_ec_keyb.c
 @@ -275,7 +275,7 @@ static int cros_ec_keyb_probe(struct platform_device 
 *pdev)
  ckdev-dev = dev;
  dev_set_drvdata(pdev-dev, ckdev);
  
 -idev-name = ec-ec_name;
 +idev-name = CROS_EC_DEV_NAME;
  idev-phys = ec-phys_name;
  __set_bit(EV_REP, idev-evbit);
  
 diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
 index 08d82bfc5268..99292bc2fe5f 100644
 --- a/drivers/mfd/cros_ec.c
 +++ b/drivers/mfd/cros_ec.c
 @@ -24,12 +24,48 @@
  #include linux/mfd/core.h
  #include linux/mfd/cros_ec.h
  
 -static const struct mfd_cell cros_devs[] = {
 -{
 +static int dev_id;
 +
 +static int cros_ec_dev_register(struct cros_ec_device *ec_dev,
 +int dev_id, int devidx)
 
 What's the difference between dev_id and devidx.
 
 Confusing don't you think?

dev_id is the id that mfd_add_devices() expects and devidx is the ChromeOS
EC device index. Since the first EC is called cros_ec and the second one
is called cros_pd.

I'll rename devidx to ec_dev_index to make it more clear.

 
 +{
 +struct device *dev = ec_dev-dev;
 +struct cros_ec_platform ec_p = {
 +.cmd_offset = 0,
 +};
 +
 +struct mfd_cell ec_cell = {
  .name = cros-ec-ctl,
  .id = PLATFORM_DEVID_AUTO,
 -},
 -};
 +.platform_data = ec_p,
 +.pdata_size = sizeof(ec_p),
 +};
 
 Why have you bought this into here?  The convention is usually to have
 this at the top of the file, outside any functions.  Declaring and
 initialising structs inside functions makes things looks messy IMHO.


The problem is that not all ChromeOS EC have a chained Power Delivery (PD)
EC so on runtime the Application Processor (AP) asks the host EC if there
is a PD and only in that case calls cros_ec_dev_register() for the PD EC.

That's why the struct mfd_cell is allocated inside the function as a stack
local variable and is not declared as a static mfd cells array at the top
as it is in other MFD drivers.

 
 
 +switch (devidx) {
 +case 0:
 
 Please define these.  I have no idea what devidx 0 or 1 is.


Ok, those are just a device index but I'll define it as CROS_EC_DEV_EC_INDEX
and CROS_EC_DEV_PD_INDEX to make it more readable.

 +if (IS_ENABLED(CONFIG_OF)  dev-of_node) {
 +ec_p.ec_name = of_get_property(dev-of_node, devname,
 +   NULL);
 +if (ec_p.ec_name == NULL) {
 
 if (!ec_p.ec_name)


Ok.

 +dev_dbg(dev,
 +Device name not found, using default);
 +ec_p.ec_name = CROS_EC_DEV_NAME;
 +}
 +} else {
 +ec_p.ec_name = CROS_EC_DEV_NAME;
 +

Re: [PATCH v3 6/7] mfd: cros_ec: Support multiple EC in a system

2015-05-28 Thread Lee Jones 
On Thu, 28 May 2015, Javier Martinez Canillas wrote:

 Hello Lee,
 
 Thanks a lot for your feedback.
 
 On 05/27/2015 11:11 AM, Lee Jones wrote:
  On Fri, 22 May 2015, Javier Martinez Canillas wrote:
  
  From: Gwendal Grignou gwen...@chromium.org
  
  Chromebooks can have more than one Embedded Controller so the
  cros_ec device id has to be incremented for each EC registered.
  
  Add code to handle multiple EC. First ec found is cros-ec0,
  second cros-ec1 and so on.
  
  Add a new structure to represent multiple EC as different char
  devices (e.g: /dev/cros_ec, /dev/cros_pd). It connects to
  cros_ec_device and allows sysfs inferface for cros_pd.
  
  Also reduce number of allocated objects, make chromeos sysfs
  class object a static and add refcounting to prevent object
  deletion while command is in progress.
  
  Signed-off-by: Gwendal Grignou gwen...@chromium.org
  Reviewed-by: Dmitry Torokhov d...@chromium.org
  Signed-off-by: Javier Martinez Canillas javier.marti...@collabora.co.uk
  ---
  
  Changes since v2: None
  
  Changes since v1:
- Squash patch that adds support to represent EC's as different
  char devices (e.g: /dev/cros_ec, /dev/cros_pd):
  https://chromium-review.googlesource.com/#/c/217297/
  Suggested by Gwendal Grignou
- Use cros_ec instead of cros-ec in the subject line to be consistent.
  Suggested by Gwendal Grignou
  ---
   drivers/input/keyboard/cros_ec_keyb.c  |   2 +-
   drivers/mfd/cros_ec.c  |  66 +--
   drivers/mfd/cros_ec_i2c.c  |   1 -
   drivers/mfd/cros_ec_spi.c  |   1 -
   drivers/platform/chrome/cros_ec_dev.c  | 128 
  -
   drivers/platform/chrome/cros_ec_dev.h  |   7 --
   drivers/platform/chrome/cros_ec_lightbar.c |  75 +
   drivers/platform/chrome/cros_ec_lpc.c  |   1 -
   drivers/platform/chrome/cros_ec_sysfs.c|  48 +--
   include/linux/mfd/cros_ec.h|  44 --
   10 files changed, 247 insertions(+), 126 deletions(-)

[...]

  @@ -52,14 +88,28 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
   
 cros_ec_query_all(ec_dev);
   
  -  err = mfd_add_devices(dev, 0, cros_devs,
  -ARRAY_SIZE(cros_devs),
  -NULL, ec_dev-irq, NULL);
  +  err = cros_ec_dev_register(ec_dev, dev_id++, 0);
 if (err) {
  -  dev_err(dev, failed to add mfd devices\n);
  +  dev_err(dev, failed to add ec\n);
 return err;
 }
   
  +  if (ec_dev-max_passthru) {
  +  /*
  +   * Register a PD device as well on top of this device.
  +   * We make the following assumptions:
  +   * - behind an EC, we have a pd
  +   * - only one device added.
  +   * - the EC is responsive at init time (it is not true for a
  +   *   sensor hub.
  +   */
  +  err = cros_ec_dev_register(ec_dev, dev_id++, 1);
  
  I don't really like this devidx business.  Just keep it simple and
  define more than one mfd_cell structure.
 
 I explained to you that this is done because the number of cells depends on
 the system. I can have an array of mfd_cell structures and use the index to
 register but I don't think that is easier to understand.

Keep it simple.  Create a static struct for each and:

mfd_add_devices(ec_cell)

if (ec_dev-max_passthru)
   mfd_add_devices(ec_pd_cell)

  +  if (err) {
  +  dev_err(dev, failed to add additional ec\n);
  +  return err;
  +  }
  +  }
  +
 if (IS_ENABLED(CONFIG_OF)  dev-of_node) {
 err = of_platform_populate(dev-of_node, NULL, NULL, dev);
 if (err) {
  
 
 Best regards,
 Javier

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
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Re: [PATCH v3 6/7] mfd: cros_ec: Support multiple EC in a system

2015-05-28 Thread Javier Martinez Canillas 
Hello Lee,

[...]

On 05/28/2015 04:26 PM, Lee Jones wrote:
   
  + if (ec_dev-max_passthru) {
  + /*
  +  * Register a PD device as well on top of this device.
  +  * We make the following assumptions:
  +  * - behind an EC, we have a pd
  +  * - only one device added.
  +  * - the EC is responsive at init time (it is not true for a
  +  *   sensor hub.
  +  */
  + err = cros_ec_dev_register(ec_dev, dev_id++, 1);
  
  I don't really like this devidx business.  Just keep it simple and
  define more than one mfd_cell structure.
 
 I explained to you that this is done because the number of cells depends on
 the system. I can have an array of mfd_cell structures and use the index to
 register but I don't think that is easier to understand.
 
 Keep it simple.  Create a static struct for each and:
 
 mfd_add_devices(ec_cell)
 
 if (ec_dev-max_passthru)
mfd_add_devices(ec_pd_cell)


Ok, will do.

Thanks a lot for your feedback.

Best regards,
Javier
 
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Re: [PATCH v3 6/7] mfd: cros_ec: Support multiple EC in a system

2015-05-27 Thread Lee Jones 
On Fri, 22 May 2015, Javier Martinez Canillas wrote:

 From: Gwendal Grignou gwen...@chromium.org
 
 Chromebooks can have more than one Embedded Controller so the
 cros_ec device id has to be incremented for each EC registered.
 
 Add code to handle multiple EC. First ec found is cros-ec0,
 second cros-ec1 and so on.
 
 Add a new structure to represent multiple EC as different char
 devices (e.g: /dev/cros_ec, /dev/cros_pd). It connects to
 cros_ec_device and allows sysfs inferface for cros_pd.
 
 Also reduce number of allocated objects, make chromeos sysfs
 class object a static and add refcounting to prevent object
 deletion while command is in progress.
 
 Signed-off-by: Gwendal Grignou gwen...@chromium.org
 Reviewed-by: Dmitry Torokhov d...@chromium.org
 Signed-off-by: Javier Martinez Canillas javier.marti...@collabora.co.uk
 ---
 
 Changes since v2: None
 
 Changes since v1:
   - Squash patch that adds support to represent EC's as different
 char devices (e.g: /dev/cros_ec, /dev/cros_pd):
 https://chromium-review.googlesource.com/#/c/217297/
 Suggested by Gwendal Grignou
   - Use cros_ec instead of cros-ec in the subject line to be consistent.
 Suggested by Gwendal Grignou
 ---
  drivers/input/keyboard/cros_ec_keyb.c  |   2 +-
  drivers/mfd/cros_ec.c  |  66 +--
  drivers/mfd/cros_ec_i2c.c  |   1 -
  drivers/mfd/cros_ec_spi.c  |   1 -
  drivers/platform/chrome/cros_ec_dev.c  | 128 
 -
  drivers/platform/chrome/cros_ec_dev.h  |   7 --
  drivers/platform/chrome/cros_ec_lightbar.c |  75 +
  drivers/platform/chrome/cros_ec_lpc.c  |   1 -
  drivers/platform/chrome/cros_ec_sysfs.c|  48 +--
  include/linux/mfd/cros_ec.h|  44 --
  10 files changed, 247 insertions(+), 126 deletions(-)
 
 diff --git a/drivers/input/keyboard/cros_ec_keyb.c 
 b/drivers/input/keyboard/cros_ec_keyb.c
 index 974154a74505..b01966dc7eb3 100644
 --- a/drivers/input/keyboard/cros_ec_keyb.c
 +++ b/drivers/input/keyboard/cros_ec_keyb.c
 @@ -275,7 +275,7 @@ static int cros_ec_keyb_probe(struct platform_device 
 *pdev)
   ckdev-dev = dev;
   dev_set_drvdata(pdev-dev, ckdev);
  
 - idev-name = ec-ec_name;
 + idev-name = CROS_EC_DEV_NAME;
   idev-phys = ec-phys_name;
   __set_bit(EV_REP, idev-evbit);
  
 diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
 index 08d82bfc5268..99292bc2fe5f 100644
 --- a/drivers/mfd/cros_ec.c
 +++ b/drivers/mfd/cros_ec.c
 @@ -24,12 +24,48 @@
  #include linux/mfd/core.h
  #include linux/mfd/cros_ec.h
  
 -static const struct mfd_cell cros_devs[] = {
 - {
 +static int dev_id;
 +
 +static int cros_ec_dev_register(struct cros_ec_device *ec_dev,
 + int dev_id, int devidx)

What's the difference between dev_id and devidx.

Confusing don't you think?

 +{
 + struct device *dev = ec_dev-dev;
 + struct cros_ec_platform ec_p = {
 + .cmd_offset = 0,
 + };
 +
 + struct mfd_cell ec_cell = {
   .name = cros-ec-ctl,
   .id = PLATFORM_DEVID_AUTO,
 - },
 -};
 + .platform_data = ec_p,
 + .pdata_size = sizeof(ec_p),
 + };

Why have you bought this into here?  The convention is usually to have
this at the top of the file, outside any functions.  Declaring and
initialising structs inside functions makes things looks messy IMHO.



 + switch (devidx) {
 + case 0:

Please define these.  I have no idea what devidx 0 or 1 is.

 + if (IS_ENABLED(CONFIG_OF)  dev-of_node) {
 + ec_p.ec_name = of_get_property(dev-of_node, devname,
 +NULL);
 + if (ec_p.ec_name == NULL) {

if (!ec_p.ec_name)

 + dev_dbg(dev,
 + Device name not found, using default);
 + ec_p.ec_name = CROS_EC_DEV_NAME;
 + }
 + } else {
 + ec_p.ec_name = CROS_EC_DEV_NAME;
 + }

I'd save yourself a few lines and do:

if (OF)
   name = get_name();

if (!name)
   name = DEFAULT_NAME;

Then rid the 'else'.  Rid the dev_dbg() too if you can.

 + break;
 + case 1:
 + ec_p.ec_name = CROS_EC_DEV_PD_NAME;
 + break;
 + default:
 + return -EINVAL;
 + }
 +
 + ec_p.cmd_offset = EC_CMD_PASSTHRU_OFFSET(devidx);

'\n' here.

 + return mfd_add_devices(dev, dev_id, ec_cell, 1,
 +NULL, ec_dev-irq, NULL);
 +}
  
  int cros_ec_register(struct cros_ec_device *ec_dev)
  {
 @@ -52,14 +88,28 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
  
   cros_ec_query_all(ec_dev);
  
 - err = mfd_add_devices(dev, 0, cros_devs,
 -   ARRAY_SIZE(cros_devs),
 -   NULL, ec_dev-irq,