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author | Tony Lindgren <tony@atomide.com> | 2012-05-08 23:23:33 (GMT) |
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committer | Paul Walmsley <paul@pwsan.com> | 2012-05-08 23:23:33 (GMT) |
commit | ad1b6662eb5fe293e8b402497b3835710848c389 (patch) | |
tree | 99295b6160eed041bf8301533084712b9754e61e /arch/arm/mach-omap2/msdi.c | |
parent | 0135f6a04642c192bdf4b36e06937d3387e174ff (diff) | |
download | linux-ad1b6662eb5fe293e8b402497b3835710848c389.tar.xz |
ARM: OMAP2420: hwmod data: Add MMC hwmod data for 2420
Add MMC for 2420 so we can pass the DMA request lines the same
way as we already do on omap2430 and later.
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
[paul@pwsan.com: updated to apply on top of the 3.5 hwmod cleanup;
changed mmc hwmod name/class to "msdi" as documented in the 2420 TRM Rev X;
added sysconfig register information; added 16 bit register width flag;
added MSDI custom reset code]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Diffstat (limited to 'arch/arm/mach-omap2/msdi.c')
-rw-r--r-- | arch/arm/mach-omap2/msdi.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/msdi.c b/arch/arm/mach-omap2/msdi.c new file mode 100644 index 0000000..ef2a692 --- /dev/null +++ b/arch/arm/mach-omap2/msdi.c @@ -0,0 +1,88 @@ +/* + * 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 <plat/omap_hwmod.h> +#include <plat/mmc.h> + +#include "common.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 + +/* Maximum microseconds to wait for OMAP module to softreset */ +#define MAX_MODULE_SOFTRESET_WAIT 10000 + +/* 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_warning("%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; +} |