LXR linux/arch/arm/mach-omap2/msdi.c

   1/*
   2 * MSDI IP block reset
   3 *
   4 * Copyright (C) 2012 Texas Instruments, Inc.
   5 * Paul Walmsley
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * version 2 as published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful, but
  12 * WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19 * 02110-1301 USA
  20 *
  21 * XXX What about pad muxing?
  22 */
  23
  24#include <linux/kernel.h>
  25#include <linux/err.h>
  26#include <linux/platform_data/gpio-omap.h>
  27
  28#include "prm.h"
  29#include "common.h"
  30#include "control.h"
  31#include "omap_hwmod.h"
  32#include "omap_device.h"
  33#include "mux.h"
  34#include "mmc.h"
  35
  36/*
  37 * MSDI_CON_OFFSET: offset in bytes of the MSDI IP block's CON register
  38 *     from the IP block's base address
  39 */
  40#define MSDI_CON_OFFSET                         0x0c
  41
  42/* Register bitfields in the CON register */
  43#define MSDI_CON_POW_MASK                       BIT(11)
  44#define MSDI_CON_CLKD_MASK                      (0x3f << 0)
  45#define MSDI_CON_CLKD_SHIFT                     0
  46
  47/* MSDI_TARGET_RESET_CLKD: clock divisor to use throughout the reset */
  48#define MSDI_TARGET_RESET_CLKD          0x3ff
  49
  50/**
  51 * omap_msdi_reset - reset the MSDI IP block
  52 * @oh: struct omap_hwmod *
  53 *
  54 * The MSDI IP block on OMAP2420 has to have both the POW and CLKD
  55 * fields set inside its CON register for a reset to complete
  56 * successfully.  This is not documented in the TRM.  For CLKD, we use
  57 * the value that results in the lowest possible clock rate, to attempt
  58 * to avoid disturbing any cards.
  59 */
  60int omap_msdi_reset(struct omap_hwmod *oh)
  61{
  62        u16 v = 0;
  63        int c = 0;
  64
  65        /* Write to the SOFTRESET bit */
  66        omap_hwmod_softreset(oh);
  67
  68        /* Enable the MSDI core and internal clock */
  69        v |= MSDI_CON_POW_MASK;
  70        v |= MSDI_TARGET_RESET_CLKD << MSDI_CON_CLKD_SHIFT;
  71        omap_hwmod_write(v, oh, MSDI_CON_OFFSET);
  72
  73        /* Poll on RESETDONE bit */
  74        omap_test_timeout((omap_hwmod_read(oh, oh->class->sysc->syss_offs)
  75                           & SYSS_RESETDONE_MASK),
  76                          MAX_MODULE_SOFTRESET_WAIT, c);
  77
  78        if (c == MAX_MODULE_SOFTRESET_WAIT)
  79                pr_warning("%s: %s: softreset failed (waited %d usec)\n",
  80                           __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
  81        else
  82                pr_debug("%s: %s: softreset in %d usec\n", __func__,
  83                         oh->name, c);
  84
  85        /* Disable the MSDI internal clock */
  86        v &= ~MSDI_CON_CLKD_MASK;
  87        omap_hwmod_write(v, oh, MSDI_CON_OFFSET);
  88
  89        return 0;
  90}
  91
  92#if defined(CONFIG_MMC_OMAP) || defined(CONFIG_MMC_OMAP_MODULE)
  93
  94static inline void omap242x_mmc_mux(struct omap_mmc_platform_data
  95                                    *mmc_controller)
  96{
  97        if ((mmc_controller->slots[0].switch_pin > 0) && \
  98                (mmc_controller->slots[0].switch_pin < OMAP_MAX_GPIO_LINES))
  99                omap_mux_init_gpio(mmc_controller->slots[0].switch_pin,
 100                                        OMAP_PIN_INPUT_PULLUP);
 101        if ((mmc_controller->slots[0].gpio_wp > 0) && \
 102                (mmc_controller->slots[0].gpio_wp < OMAP_MAX_GPIO_LINES))
 103                omap_mux_init_gpio(mmc_controller->slots[0].gpio_wp,
 104                                        OMAP_PIN_INPUT_PULLUP);
 105
 106        omap_mux_init_signal("sdmmc_cmd", 0);
 107        omap_mux_init_signal("sdmmc_clki", 0);
 108        omap_mux_init_signal("sdmmc_clko", 0);
 109        omap_mux_init_signal("sdmmc_dat0", 0);
 110        omap_mux_init_signal("sdmmc_dat_dir0", 0);
 111        omap_mux_init_signal("sdmmc_cmd_dir", 0);
 112        if (mmc_controller->slots[0].caps & MMC_CAP_4_BIT_DATA) {
 113                omap_mux_init_signal("sdmmc_dat1", 0);
 114                omap_mux_init_signal("sdmmc_dat2", 0);
 115                omap_mux_init_signal("sdmmc_dat3", 0);
 116                omap_mux_init_signal("sdmmc_dat_dir1", 0);
 117                omap_mux_init_signal("sdmmc_dat_dir2", 0);
 118                omap_mux_init_signal("sdmmc_dat_dir3", 0);
 119        }
 120
 121        /*
 122         * Use internal loop-back in MMC/SDIO Module Input Clock
 123         * selection
 124         */
 125        if (mmc_controller->slots[0].internal_clock) {
 126                u32 v = omap_ctrl_readl(OMAP2_CONTROL_DEVCONF0);
 127                v |= (1 << 24);
 128                omap_ctrl_writel(v, OMAP2_CONTROL_DEVCONF0);
 129        }
 130}
 131
 132void __init omap242x_init_mmc(struct omap_mmc_platform_data **mmc_data)
 133{
 134        struct platform_device *pdev;
 135        struct omap_hwmod *oh;
 136        int id = 0;
 137        char *oh_name = "msdi1";
 138        char *dev_name = "mmci-omap";
 139
 140        if (!mmc_data[0]) {
 141                pr_err("%s fails: Incomplete platform data\n", __func__);
 142                return;
 143        }
 144
 145        omap242x_mmc_mux(mmc_data[0]);
 146
 147        oh = omap_hwmod_lookup(oh_name);
 148        if (!oh) {
 149                pr_err("Could not look up %s\n", oh_name);
 150                return;
 151        }
 152        pdev = omap_device_build(dev_name, id, oh, mmc_data[0],
 153                                 sizeof(struct omap_mmc_platform_data));
 154        if (IS_ERR(pdev))
 155                WARN(1, "Can'd build omap_device for %s:%s.\n",
 156                                        dev_name, oh->name);
 157}
 158
 159#endif
 160