cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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msdi.c (1967B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * MSDI IP block reset
      4 *
      5 * Copyright (C) 2012 Texas Instruments, Inc.
      6 * Paul Walmsley
      7 *
      8 * XXX What about pad muxing?
      9 */
     10
     11#include <linux/kernel.h>
     12#include <linux/err.h>
     13
     14#include "prm.h"
     15#include "common.h"
     16#include "control.h"
     17#include "omap_hwmod.h"
     18#include "omap_device.h"
     19#include "mmc.h"
     20
     21/*
     22 * MSDI_CON_OFFSET: offset in bytes of the MSDI IP block's CON register
     23 *     from the IP block's base address
     24 */
     25#define MSDI_CON_OFFSET				0x0c
     26
     27/* Register bitfields in the CON register */
     28#define MSDI_CON_POW_MASK			BIT(11)
     29#define MSDI_CON_CLKD_MASK			(0x3f << 0)
     30#define MSDI_CON_CLKD_SHIFT			0
     31
     32/* MSDI_TARGET_RESET_CLKD: clock divisor to use throughout the reset */
     33#define MSDI_TARGET_RESET_CLKD		0x3ff
     34
     35/**
     36 * omap_msdi_reset - reset the MSDI IP block
     37 * @oh: struct omap_hwmod *
     38 *
     39 * The MSDI IP block on OMAP2420 has to have both the POW and CLKD
     40 * fields set inside its CON register for a reset to complete
     41 * successfully.  This is not documented in the TRM.  For CLKD, we use
     42 * the value that results in the lowest possible clock rate, to attempt
     43 * to avoid disturbing any cards.
     44 */
     45int omap_msdi_reset(struct omap_hwmod *oh)
     46{
     47	u16 v = 0;
     48	int c = 0;
     49
     50	/* Write to the SOFTRESET bit */
     51	omap_hwmod_softreset(oh);
     52
     53	/* Enable the MSDI core and internal clock */
     54	v |= MSDI_CON_POW_MASK;
     55	v |= MSDI_TARGET_RESET_CLKD << MSDI_CON_CLKD_SHIFT;
     56	omap_hwmod_write(v, oh, MSDI_CON_OFFSET);
     57
     58	/* Poll on RESETDONE bit */
     59	omap_test_timeout((omap_hwmod_read(oh, oh->class->sysc->syss_offs)
     60			   & SYSS_RESETDONE_MASK),
     61			  MAX_MODULE_SOFTRESET_WAIT, c);
     62
     63	if (c == MAX_MODULE_SOFTRESET_WAIT)
     64		pr_warn("%s: %s: softreset failed (waited %d usec)\n",
     65			__func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
     66	else
     67		pr_debug("%s: %s: softreset in %d usec\n", __func__,
     68			 oh->name, c);
     69
     70	/* Disable the MSDI internal clock */
     71	v &= ~MSDI_CON_CLKD_MASK;
     72	omap_hwmod_write(v, oh, MSDI_CON_OFFSET);
     73
     74	return 0;
     75}