diff options
Diffstat (limited to 'arch/arm/mach-keystone/psc.c')
| -rw-r--r-- | arch/arm/mach-keystone/psc.c | 200 |
1 files changed, 156 insertions, 44 deletions
diff --git a/arch/arm/mach-keystone/psc.c b/arch/arm/mach-keystone/psc.c index 237e776e87..ff042a6db2 100644 --- a/arch/arm/mach-keystone/psc.c +++ b/arch/arm/mach-keystone/psc.c @@ -13,24 +13,27 @@ #include <asm/processor.h> #include <asm/arch/psc_defs.h> +/** + * psc_delay() - delay for psc + * + * Return: 10 + */ int psc_delay(void) { udelay(10); return 10; } -/* - * FUNCTION PURPOSE: Wait for end of transitional state - * - * DESCRIPTION: Polls pstat for the selected domain and waits for transitions - * to be complete. +/** + * psc_wait() - Wait for end of transitional state + * @domain_num: GPSC domain number * - * Since this is boot loader code it is *ASSUMED* that interrupts - * are disabled and no other core is mucking around with the psc - * at the same time. + * Polls pstat for the selected domain and waits for transitions to be complete. + * Since this is boot loader code it is *ASSUMED* that interrupts are disabled + * and no other core is mucking around with the psc at the same time. * - * Returns 0 when the domain is free. Returns -1 if a timeout - * occurred waiting for the completion. + * Return: 0 when the domain is free. Returns -1 if a timeout occurred waiting + * for the completion. */ int psc_wait(u32 domain_num) { @@ -59,6 +62,10 @@ int psc_wait(u32 domain_num) return 0; } +/** + * psc_get_domain_num() - Get the domain number + * @mod_num: LPSC module number + */ u32 psc_get_domain_num(u32 mod_num) { u32 domain_num; @@ -70,20 +77,19 @@ u32 psc_get_domain_num(u32 mod_num) return domain_num; } -/* - * FUNCTION PURPOSE: Power up/down a module - * - * DESCRIPTION: Powers up/down the requested module and the associated power - * domain if required. No action is taken it the module is - * already powered up/down. +/** + * psc_set_state() - powers up/down a module + * @mod_num: LPSC module number + * @state: 1 to enable, 0 to disable. * - * This only controls modules. The domain in which the module - * resides will be left in the power on state. Multiple modules - * can exist in a power domain, so powering down the domain based - * on a single module is not done. + * Powers up/down the requested module and the associated power domain if + * required. No action is taken it the module is already powered up/down. + * This only controls modules. The domain in which the module resides will + * be left in the power on state. Multiple modules can exist in a power + * domain, so powering down the domain based on a single module is not done. * - * Returns 0 on success, -1 if the module can't be powered up, or - * if there is a timeout waiting for the transition. + * Return: 0 on success, -1 if the module can't be powered up, or if there is a + * timeout waiting for the transition. */ int psc_set_state(u32 mod_num, u32 state) { @@ -136,15 +142,16 @@ int psc_set_state(u32 mod_num, u32 state) return psc_wait(domain_num); } -/* - * FUNCTION PURPOSE: Power up a module +/** + * psc_enable_module() - power up a module + * @mod_num: LPSC module number + * + * Powers up the requested module and the associated power domain + * if required. No action is taken it the module is already powered up. * - * DESCRIPTION: Powers up the requested module and the associated power domain - * if required. No action is taken it the module is already - * powered up. + * Return: 0 on success, -1 if the module can't be powered up, or + * if there is a timeout waiting for the transition. * - * Returns 0 on success, -1 if the module can't be powered up, or - * if there is a timeout waiting for the transition. */ int psc_enable_module(u32 mod_num) { @@ -158,12 +165,11 @@ int psc_enable_module(u32 mod_num) return psc_set_state(mod_num, PSC_REG_VAL_MDCTL_NEXT_ON); } -/* - * FUNCTION PURPOSE: Power down a module +/** + * psc_disable_module() - Power down a module + * @mod_num: LPSC module number * - * DESCRIPTION: Powers down the requested module. - * - * Returns 0 on success, -1 on failure or timeout. + * Return: 0 on success, -1 on failure or timeout. */ int psc_disable_module(u32 mod_num) { @@ -179,13 +185,16 @@ int psc_disable_module(u32 mod_num) return psc_set_state(mod_num, PSC_REG_VAL_MDCTL_NEXT_SWRSTDISABLE); } -/* - * FUNCTION PURPOSE: Set the reset isolation bit in mdctl +/** + * psc_set_reset_iso() - Set the reset isolation bit in mdctl + * @mod_num: LPSC module number + * + * The reset isolation enable bit is set. The state of the module is not + * changed. * - * DESCRIPTION: The reset isolation enable bit is set. The state of the module - * is not changed. Returns 0 if the module config showed that - * reset isolation is supported. Returns 1 otherwise. This is not - * an error, but setting the bit in mdctl has no effect. + * Return: 0 if the module config showed that reset isolation is supported. + * Returns 1 otherwise. This is not an error, but setting the bit in mdctl + * has no effect. */ int psc_set_reset_iso(u32 mod_num) { @@ -204,10 +213,9 @@ int psc_set_reset_iso(u32 mod_num) return 1; } -/* - * FUNCTION PURPOSE: Disable a power domain - * - * DESCRIPTION: The power domain is disabled +/** + * psc_disable_domain() - Disable a power domain + * @domain_num: GPSC domain number */ int psc_disable_domain(u32 domain_num) { @@ -225,3 +233,107 @@ int psc_disable_domain(u32 domain_num) return psc_wait(domain_num); } + +/** + * psc_module_keep_in_reset_enabled() - Keep module in enabled,in-reset state + * @mod_num: LPSC module number + * @gate_clocks: Can the clocks be gated on this module? + * + * Enable the module, but do not release the module from local reset. This is + * necessary for many processor systems on keystone SoCs to allow for system + * initialization from a master processor prior to releasing the processor + * from reset. + */ +int psc_module_keep_in_reset_enabled(u32 mod_num, bool gate_clocks) +{ + u32 mdctl, ptcmd, mdstat; + u32 next_state; + int domain_num = psc_get_domain_num(mod_num); + int timeout = 100000; + + /* Wait for any previous transitions to complete */ + psc_wait(domain_num); + mdctl = __raw_readl(KS2_PSC_BASE + PSC_REG_MDCTL(mod_num)); + /* Should be set 0 to assert Local reset */ + if ((mdctl & PSC_REG_MDCTL_SET_LRSTZ(mdctl, 1))) { + mdctl = PSC_REG_MDCTL_SET_LRSTZ(mdctl, 0); + __raw_writel(mdctl, KS2_PSC_BASE + PSC_REG_MDCTL(mod_num)); + /* Wait for transition to take place */ + psc_wait(domain_num); + } + + /* Clear Module reset */ + mdctl = __raw_readl(KS2_PSC_BASE + PSC_REG_MDCTL(mod_num)); + next_state = gate_clocks ? PSC_REG_VAL_MDCTL_NEXT_OFF : + PSC_REG_VAL_MDCTL_NEXT_ON; + mdctl = PSC_REG_MDCTL_SET_NEXT(mdctl, next_state); + __raw_writel(mdctl, KS2_PSC_BASE + PSC_REG_MDCTL(mod_num)); + /* Trigger PD transition */ + ptcmd = __raw_readl(KS2_PSC_BASE + PSC_REG_PTCMD); + ptcmd |= (u32)(1 << domain_num); + __raw_writel(ptcmd, KS2_PSC_BASE + PSC_REG_PTCMD); + psc_wait(domain_num); + + mdstat = __raw_readl(KS2_PSC_BASE + PSC_REG_MDSTAT(mod_num)); + while (timeout) { + mdstat = __raw_readl(KS2_PSC_BASE + PSC_REG_MDSTAT(mod_num)); + + if (!(PSC_REG_MDSTAT_GET_STATUS(mdstat) & 0x30) && + PSC_REG_MDSTAT_GET_MRSTDONE(mdstat) && + PSC_REG_MDSTAT_GET_LRSTDONE(mdstat)) + break; + timeout--; + } + + if (!timeout) { + printf("%s: Timedout waiting for mdstat(0x%08x) to change\n", + __func__, mdstat); + return -ETIMEDOUT; + } + return 0; +} + +/** + * psc_module_release_from_reset() - Release the module from reset + * @mod_num: LPSC module number + * + * This is the follow through for the command 'psc_module_keep_in_reset_enabled' + * Allowing the module to be released from reset once all required inits are + * complete for the module. Typically, this allows the processor module to start + * execution. + */ +int psc_module_release_from_reset(u32 mod_num) +{ + u32 mdctl, mdstat; + int domain_num = psc_get_domain_num(mod_num); + int timeout = 100000; + + /* Wait for any previous transitions to complete */ + psc_wait(domain_num); + mdctl = __raw_readl(KS2_PSC_BASE + PSC_REG_MDCTL(mod_num)); + /* Should be set to 1 to de-assert Local reset */ + if ((mdctl & PSC_REG_MDCTL_SET_LRSTZ(mdctl, 0))) { + mdctl = PSC_REG_MDCTL_SET_LRSTZ(mdctl, 1); + __raw_writel(mdctl, KS2_PSC_BASE + PSC_REG_MDCTL(mod_num)); + /* Wait for transition to take place */ + psc_wait(domain_num); + } + mdstat = __raw_readl(KS2_PSC_BASE + PSC_REG_MDSTAT(mod_num)); + while (timeout) { + mdstat = __raw_readl(KS2_PSC_BASE + PSC_REG_MDSTAT(mod_num)); + + if (!(PSC_REG_MDSTAT_GET_STATUS(mdstat) & 0x30) && + PSC_REG_MDSTAT_GET_MRSTDONE(mdstat) && + PSC_REG_MDSTAT_GET_LRSTDONE(mdstat)) + break; + timeout--; + } + + if (!timeout) { + printf("%s: Timedout waiting for mdstat(0x%08x) to change\n", + __func__, mdstat); + return -ETIMEDOUT; + } + + return 0; +} |