diff options
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/mach-omap2/omap_hwmod.c | 152 |
1 files changed, 120 insertions, 32 deletions
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index 503832e20d56..6c6d31b432d2 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -1534,10 +1534,9 @@ static int _enable(struct omap_hwmod *oh) pr_debug("omap_hwmod: %s: enabling\n", oh->name); /* - * hwmods with HWMOD_INIT_NO_IDLE flag set are left - * in enabled state at init. - * Now that someone is really trying to enable them, - * just ensure that the hwmod mux is set. + * hwmods with HWMOD_INIT_NO_IDLE flag set are left in enabled + * state at init. Now that someone is really trying to enable + * them, just ensure that the hwmod mux is set. */ if (oh->_int_flags & _HWMOD_SKIP_ENABLE) { /* @@ -1819,46 +1818,60 @@ static int __init _init(struct omap_hwmod *oh, void *data) } /** - * _setup - do initial configuration of omap_hwmod + * _setup_iclk_autoidle - configure an IP block's interface clocks * @oh: struct omap_hwmod * * - * Writes the CLOCKACTIVITY bits @clockact to the hwmod @oh - * OCP_SYSCONFIG register. Returns 0. + * Set up the module's interface clocks. XXX This function is still mostly + * a stub; implementing this properly requires iclk autoidle usecounting in + * the clock code. No return value. */ -static int _setup(struct omap_hwmod *oh, void *data) +static void __init _setup_iclk_autoidle(struct omap_hwmod *oh) { - int i, r; - u8 postsetup_state; + int i; if (oh->_state != _HWMOD_STATE_INITIALIZED) - return 0; + return; - /* Set iclk autoidle mode */ - if (oh->slaves_cnt > 0) { - for (i = 0; i < oh->slaves_cnt; i++) { - struct omap_hwmod_ocp_if *os = oh->slaves[i]; - struct clk *c = os->_clk; + for (i = 0; i < oh->slaves_cnt; i++) { + struct omap_hwmod_ocp_if *os = oh->slaves[i]; + struct clk *c = os->_clk; - if (!c) - continue; + if (!c) + continue; - if (os->flags & OCPIF_SWSUP_IDLE) { - /* XXX omap_iclk_deny_idle(c); */ - } else { - /* XXX omap_iclk_allow_idle(c); */ - clk_enable(c); - } + if (os->flags & OCPIF_SWSUP_IDLE) { + /* XXX omap_iclk_deny_idle(c); */ + } else { + /* XXX omap_iclk_allow_idle(c); */ + clk_enable(c); } } - oh->_state = _HWMOD_STATE_INITIALIZED; + return; +} + +/** + * _setup_reset - reset an IP block during the setup process + * @oh: struct omap_hwmod * + * + * Reset the IP block corresponding to the hwmod @oh during the setup + * process. The IP block is first enabled so it can be successfully + * reset. Returns 0 upon success or a negative error code upon + * failure. + */ +static int __init _setup_reset(struct omap_hwmod *oh) +{ + int r; + + if (oh->_state != _HWMOD_STATE_INITIALIZED) + return -EINVAL; /* * In the case of hwmod with hardreset that should not be * de-assert at boot time, we have to keep the module * initialized, because we cannot enable it properly with the - * reset asserted. Exit without warning because that behavior is - * expected. + * reset asserted. Exit without warning because that behavior + * is expected. */ if ((oh->flags & HWMOD_INIT_NO_RESET) && oh->rst_lines_cnt > 0) return 0; @@ -1871,7 +1884,53 @@ static int _setup(struct omap_hwmod *oh, void *data) } if (!(oh->flags & HWMOD_INIT_NO_RESET)) - _reset(oh); + r = _reset(oh); + + return r; +} + +/** + * _setup_postsetup - transition to the appropriate state after _setup + * @oh: struct omap_hwmod * + * + * Place an IP block represented by @oh into a "post-setup" state -- + * either IDLE, ENABLED, or DISABLED. ("post-setup" simply means that + * this function is called at the end of _setup().) The postsetup + * state for an IP block can be changed by calling + * omap_hwmod_enter_postsetup_state() early in the boot process, + * before one of the omap_hwmod_setup*() functions are called for the + * IP block. + * + * The IP block stays in this state until a PM runtime-based driver is + * loaded for that IP block. A post-setup state of IDLE is + * appropriate for almost all IP blocks with runtime PM-enabled + * drivers, since those drivers are able to enable the IP block. A + * post-setup state of ENABLED is appropriate for kernels with PM + * runtime disabled. The DISABLED state is appropriate for unusual IP + * blocks such as the MPU WDTIMER on kernels without WDTIMER drivers + * included, since the WDTIMER starts running on reset and will reset + * the MPU if left active. + * + * This post-setup mechanism is deprecated. Once all of the OMAP + * drivers have been converted to use PM runtime, and all of the IP + * block data and interconnect data is available to the hwmod code, it + * should be possible to replace this mechanism with a "lazy reset" + * arrangement. In a "lazy reset" setup, each IP block is enabled + * when the driver first probes, then all remaining IP blocks without + * drivers are either shut down or enabled after the drivers have + * loaded. However, this cannot take place until the above + * preconditions have been met, since otherwise the late reset code + * has no way of knowing which IP blocks are in use by drivers, and + * which ones are unused. + * + * No return value. + */ +static void __init _setup_postsetup(struct omap_hwmod *oh) +{ + u8 postsetup_state; + + if (oh->rst_lines_cnt > 0) + return; postsetup_state = oh->_postsetup_state; if (postsetup_state == _HWMOD_STATE_UNKNOWN) @@ -1895,6 +1954,35 @@ static int _setup(struct omap_hwmod *oh, void *data) WARN(1, "hwmod: %s: unknown postsetup state %d! defaulting to enabled\n", oh->name, postsetup_state); + return; +} + +/** + * _setup - prepare IP block hardware for use + * @oh: struct omap_hwmod * + * @n: (unused, pass NULL) + * + * Configure the IP block represented by @oh. This may include + * enabling the IP block, resetting it, and placing it into a + * post-setup state, depending on the type of IP block and applicable + * flags. IP blocks are reset to prevent any previous configuration + * by the bootloader or previous operating system from interfering + * with power management or other parts of the system. The reset can + * be avoided; see omap_hwmod_no_setup_reset(). This is the second of + * two phases for hwmod initialization. Code called here generally + * affects the IP block hardware, or system integration hardware + * associated with the IP block. Returns 0. + */ +static int __init _setup(struct omap_hwmod *oh, void *data) +{ + if (oh->_state != _HWMOD_STATE_INITIALIZED) + return 0; + + _setup_iclk_autoidle(oh); + + if (!_setup_reset(oh)) + _setup_postsetup(oh); + return 0; } @@ -2700,10 +2788,10 @@ int omap_hwmod_for_each_by_class(const char *classname, * @state: state that _setup() should leave the hwmod in * * Sets the hwmod state that @oh will enter at the end of _setup() - * (called by omap_hwmod_setup_*()). Only valid to call between - * calling omap_hwmod_register() and omap_hwmod_setup_*(). Returns - * 0 upon success or -EINVAL if there is a problem with the arguments - * or if the hwmod is in the wrong state. + * (called by omap_hwmod_setup_*()). See also the documentation + * for _setup_postsetup(), above. Returns 0 upon success or + * -EINVAL if there is a problem with the arguments or if the hwmod is + * in the wrong state. */ int omap_hwmod_set_postsetup_state(struct omap_hwmod *oh, u8 state) { |