diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index 4997c1a8b59ddf86ffe6bd516d9aee2d7c69c140..5b07ad0251d7c24b01a98067c12c4d66c74987ef 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -2,7 +2,7 @@ * omap_hwmod implementation for OMAP2/3/4 * * Copyright (C) 2009-2011 Nokia Corporation - * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011-2012 Texas Instruments, Inc. * * Paul Walmsley, BenoƮt Cousson, Kevin Hilman * @@ -1382,9 +1382,9 @@ static int _read_hardreset(struct omap_hwmod *oh, const char *name) * @oh: struct omap_hwmod * * * Resets an omap_hwmod @oh via the OCP_SYSCONFIG bit. hwmod must be - * enabled for this to work. Returns -EINVAL if the hwmod cannot be - * reset this way or if the hwmod is in the wrong state, -ETIMEDOUT if - * the module did not reset in time, or 0 upon success. + * enabled for this to work. Returns -ENOENT if the hwmod cannot be + * reset this way, -EINVAL if the hwmod is in the wrong state, + * -ETIMEDOUT if the module did not reset in time, or 0 upon success. * * In OMAP3 a specific SYSSTATUS register is used to get the reset status. * Starting in OMAP4, some IPs do not have SYSSTATUS registers and instead @@ -1401,7 +1401,7 @@ static int _ocp_softreset(struct omap_hwmod *oh) if (!oh->class->sysc || !(oh->class->sysc->sysc_flags & SYSC_HAS_SOFTRESET)) - return -EINVAL; + return -ENOENT; /* clocks must be on for this operation */ if (oh->_state != _HWMOD_STATE_ENABLED) { @@ -1462,37 +1462,60 @@ static int _ocp_softreset(struct omap_hwmod *oh) * _reset - reset an omap_hwmod * @oh: struct omap_hwmod * * - * Resets an omap_hwmod @oh. The default software reset mechanism for - * most OMAP IP blocks is triggered via the OCP_SYSCONFIG.SOFTRESET - * bit. However, some hwmods cannot be reset via this method: some - * are not targets and therefore have no OCP header registers to - * access; others (like the IVA) have idiosyncratic reset sequences. - * So for these relatively rare cases, custom reset code can be - * supplied in the struct omap_hwmod_class .reset function pointer. - * Passes along the return value from either _reset() or the custom - * reset function - these must return -EINVAL if the hwmod cannot be - * reset this way or if the hwmod is in the wrong state, -ETIMEDOUT if - * the module did not reset in time, or 0 upon success. + * Resets an omap_hwmod @oh. If the module has a custom reset + * function pointer defined, then call it to reset the IP block, and + * pass along its return value to the caller. Otherwise, if the IP + * block has an OCP_SYSCONFIG register with a SOFTRESET bitfield + * associated with it, call a function to reset the IP block via that + * method, and pass along the return value to the caller. Finally, if + * the IP block has some hardreset lines associated with it, assert + * all of those, but do _not_ deassert them. (This is because driver + * authors have expressed an apparent requirement to control the + * deassertion of the hardreset lines themselves.) + * + * The default software reset mechanism for most OMAP IP blocks is + * triggered via the OCP_SYSCONFIG.SOFTRESET bit. However, some + * hwmods cannot be reset via this method. Some are not targets and + * therefore have no OCP header registers to access. Others (like the + * IVA) have idiosyncratic reset sequences. So for these relatively + * rare cases, custom reset code can be supplied in the struct + * omap_hwmod_class .reset function pointer. Passes along the return + * value from either _ocp_softreset() or the custom reset function - + * these must return -EINVAL if the hwmod cannot be reset this way or + * if the hwmod is in the wrong state, -ETIMEDOUT if the module did + * not reset in time, or 0 upon success. */ static int _reset(struct omap_hwmod *oh) { - int ret; + int i, r; pr_debug("omap_hwmod: %s: resetting\n", oh->name); + if (oh->class->reset) { + r = oh->class->reset(oh); + } else { + if (oh->rst_lines_cnt > 0) { + for (i = 0; i < oh->rst_lines_cnt; i++) + _assert_hardreset(oh, oh->rst_lines[i].name); + return 0; + } else { + r = _ocp_softreset(oh); + if (r == -ENOENT) + r = 0; + } + } + /* - * XXX We're not resetting modules with hardreset lines - * automatically here. Should we do this also, or just expect - * those modules to define custom reset functions? + * OCP_SYSCONFIG bits need to be reprogrammed after a + * softreset. The _enable() function should be split to avoid + * the rewrite of the OCP_SYSCONFIG register. */ - ret = (oh->class->reset) ? oh->class->reset(oh) : _ocp_softreset(oh); - if (oh->class->sysc) { _update_sysc_cache(oh); _enable_sysc(oh); } - return ret; + return r; } /**