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authorPaul Walmsley <paul@pwsan.com>2008-06-25 18:09:37 -0600
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-08-21 21:26:39 +0100
commit0b7cbfb5e1f03f58241bf236cca303ee45e14b4f (patch)
treee5507290b827ee4fa60cf7a7a7f3f473d2c1a453 /arch/arm/plat-omap
parent5955902fb5c31f6a784ddb7aa16079a2bec588f5 (diff)
[ARM] OMAP3 pwrdm: add hardware save-and-restore (SAR) support
OMAP3430ES2+ introduces a new feature: optional powerdomain context hardware save-and-restore (SAR). Currently, this feature only applies to USBHOST and USBTLL module context when the USBHOST or CORE powerdomains enter a low-power sleep state[1]. This feature avoids re-enumeration of USB devices when the powerdomains return from idle, which is potentially time-consuming. This patch adds support for enabling and disabling hardware save-and-restore to the powerdomain code. Three new functions are added, pwrdm_enable_hdwr_sar(), pwrdm_disable_hdwr_sar(), and pwrdm_can_hdwr_sar(). A new struct powerdomain "flags" field is added, with a PWRDM_HAS_HDWR_SAR flag to indicate powerdomains with SAR support. Thanks to Jouni Högander <jouni.hogander@nokia.com> for reviewing an earlier version of these patches, and Richard Woodruff <r-woodruff2@ti.com> for clarifying the purpose of these bits. 1. For the USBHOST controller module, context loss occurs when the USBHOST powerdomain enters off-idle. For USBTLL, context loss occurs either if CORE enters off-idle, or if the CORE logic is configured to turn off when CORE enters retention-idle (OSWR). 34xx ES2 TRM 4.8.6.1.1, 4.8.6.1.2 Signed-off-by: Paul Walmsley <paul@pwsan.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/plat-omap')
-rw-r--r--arch/arm/plat-omap/include/mach/powerdomain.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/include/mach/powerdomain.h b/arch/arm/plat-omap/include/mach/powerdomain.h
index 5fa666fa9be..2806a9c8e4d 100644
--- a/arch/arm/plat-omap/include/mach/powerdomain.h
+++ b/arch/arm/plat-omap/include/mach/powerdomain.h
@@ -38,6 +38,10 @@
#define PWRSTS_OFF_RET_ON (PWRSTS_OFF_RET | (1 << PWRDM_POWER_ON))
+/* Powerdomain flags */
+#define PWRDM_HAS_HDWR_SAR (1 << 0) /* hardware save-and-restore support */
+
+
/*
* Number of memory banks that are power-controllable. On OMAP3430, the
* maximum is 4.
@@ -96,6 +100,9 @@ struct powerdomain {
/* Possible logic power states when pwrdm in RETENTION */
const u8 pwrsts_logic_ret;
+ /* Powerdomain flags */
+ const u8 flags;
+
/* Number of software-controllable memory banks in this powerdomain */
const u8 banks;
@@ -150,6 +157,10 @@ int pwrdm_read_prev_logic_pwrst(struct powerdomain *pwrdm);
int pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank);
int pwrdm_read_prev_mem_pwrst(struct powerdomain *pwrdm, u8 bank);
+int pwrdm_enable_hdwr_sar(struct powerdomain *pwrdm);
+int pwrdm_disable_hdwr_sar(struct powerdomain *pwrdm);
+bool pwrdm_has_hdwr_sar(struct powerdomain *pwrdm);
+
int pwrdm_wait_transition(struct powerdomain *pwrdm);
#endif