Commit 7c6b0892 authored by Ulf Hansson's avatar Ulf Hansson Committed by Shawn Guo
Browse files

firmware: imx: scu-pd: Update comments for single global power domain 



Since the introduction of the PM domain support for the scu-pd, the genpd
framework has been continuously improved. More preciously, using a single
global power domain can quite easily be deployed for imx platforms.

To avoid confusions, let's therefore make an update to the comments about
the missing pieces.

Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: default avatarShawn Guo <shawnguo@kernel.org>
parent 893cfb99

drivers/firmware/imx/scu-pd.c

+9 −2
Original line number Original line Diff line number Diff line
@@ -29,6 +29,10 @@ 
 *    The framework needs some proper extension to support multi power

 *    The framework needs some proper extension to support multi power

 *    domain cases.

 *    domain cases.

 *

 *

 *    Update: Genpd assigns the ->of_node for the virtual device before it

 *    invokes ->attach_dev() callback, hence parsing for device resources via

 *    DT should work fine.

 *

 * 2. It also breaks most of current drivers as the driver probe sequence

 * 2. It also breaks most of current drivers as the driver probe sequence

 *    behavior changed if removing ->power_on|off() callback and use

 *    behavior changed if removing ->power_on|off() callback and use

 *    ->start() and ->stop() instead. genpd_dev_pm_attach will only power

 *    ->start() and ->stop() instead. genpd_dev_pm_attach will only power
@@ -39,8 +43,11 @@ 
 *    domain enabled will trigger a HW access error. That means we need fix

 *    domain enabled will trigger a HW access error. That means we need fix

 *    most drivers probe sequence with proper runtime pm.

 *    most drivers probe sequence with proper runtime pm.

 *

 *

 * In summary, we need fix above two issue before being able to switch to

 *    Update: Runtime PM support isn't necessary. Instead, this can easily be

 * the "single global power domain" way.

 *    fixed in drivers by adding a call to dev_pm_domain_start() during probe.

 *

 * In summary, the second part needs to be addressed via minor updates to the

 * relevant drivers, before the "single global power domain" model can be used.

 *

 *

 */

 */