/* * MSDI IP block reset * * Copyright (C) 2012 Texas Instruments, Inc. * Paul Walmsley * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA * * XXX What about pad muxing? */ #include <linux/kernel.h> #include <linux/err.h> #include "prm.h" #include "common.h" #include "control.h" #include "omap_hwmod.h" #include "omap_device.h" #include "mmc.h" /* * MSDI_CON_OFFSET: offset in bytes of the MSDI IP block's CON register * from the IP block's base address */ #define MSDI_CON_OFFSET 0x0c /* Register bitfields in the CON register */ #define MSDI_CON_POW_MASK BIT(11) #define MSDI_CON_CLKD_MASK (0x3f << 0) #define MSDI_CON_CLKD_SHIFT 0 /* MSDI_TARGET_RESET_CLKD: clock divisor to use throughout the reset */ #define MSDI_TARGET_RESET_CLKD 0x3ff /** * omap_msdi_reset - reset the MSDI IP block * @oh: struct omap_hwmod * * * The MSDI IP block on OMAP2420 has to have both the POW and CLKD * fields set inside its CON register for a reset to complete * successfully. This is not documented in the TRM. For CLKD, we use * the value that results in the lowest possible clock rate, to attempt * to avoid disturbing any cards. */ int omap_msdi_reset(struct omap_hwmod *oh) { u16 v = 0; int c = 0; /* Write to the SOFTRESET bit */ omap_hwmod_softreset(oh); /* Enable the MSDI core and internal clock */ v |= MSDI_CON_POW_MASK; v |= MSDI_TARGET_RESET_CLKD << MSDI_CON_CLKD_SHIFT; omap_hwmod_write(v, oh, MSDI_CON_OFFSET); /* Poll on RESETDONE bit */ omap_test_timeout((omap_hwmod_read(oh, oh->class->sysc->syss_offs) & SYSS_RESETDONE_MASK), MAX_MODULE_SOFTRESET_WAIT, c); if (c == MAX_MODULE_SOFTRESET_WAIT) pr_warn("%s: %s: softreset failed (waited %d usec)\n", __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT); else pr_debug("%s: %s: softreset in %d usec\n", __func__, oh->name, c); /* Disable the MSDI internal clock */ v &= ~MSDI_CON_CLKD_MASK; omap_hwmod_write(v, oh, MSDI_CON_OFFSET); return 0; }