From 0b7cbfb5e1f03f58241bf236cca303ee45e14b4f Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Wed, 25 Jun 2008 18:09:37 -0600 Subject: [ARM] OMAP3 pwrdm: add hardware save-and-restore (SAR) support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 for reviewing an earlier version of these patches, and Richard Woodruff 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 Signed-off-by: Tony Lindgren Signed-off-by: Russell King --- arch/arm/plat-omap/include/mach/powerdomain.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch/arm/plat-omap/include/mach') diff --git a/arch/arm/plat-omap/include/mach/powerdomain.h b/arch/arm/plat-omap/include/mach/powerdomain.h index 5fa666fa9be8..2806a9c8e4d7 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 -- cgit v1.2.1