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 "common.h"
  29 #include "control.h"
  30 #include "omap_hwmod.h"
  31 #include "omap_device.h"
  32 #include "mux.h"
  33 #include "mmc.h"
  34
  35 /*
  36  * MSDI_CON_OFFSET: offset in bytes of the MSDI IP block's CON register
  37  *     from the IP block's base address
  38  */
  39 #define MSDI_CON_OFFSET                         0x0c
  40
  41 /* Register bitfields in the CON register */
  42 #define MSDI_CON_POW_MASK                       BIT(11)
  43 #define MSDI_CON_CLKD_MASK                      (0x3f << 0)
  44 #define MSDI_CON_CLKD_SHIFT                     0
  45
  46 /* Maximum microseconds to wait for OMAP module to softreset */
  47 #define MAX_MODULE_SOFTRESET_WAIT       10000
  48
  49 /* MSDI_TARGET_RESET_CLKD: clock divisor to use throughout the reset */
  50 #define MSDI_TARGET_RESET_CLKD          0x3ff
  51
  52 /**
  53  * omap_msdi_reset - reset the MSDI IP block
  54  * @oh: struct omap_hwmod *
  55  *
  56  * The MSDI IP block on OMAP2420 has to have both the POW and CLKD
  57  * fields set inside its CON register for a reset to complete
  58  * successfully.  This is not documented in the TRM.  For CLKD, we use
  59  * the value that results in the lowest possible clock rate, to attempt
  60  * to avoid disturbing any cards.
  61  */
  62 int omap_msdi_reset(struct omap_hwmod *oh)
  63 {
  64         u16 v = 0;
  65         int c = 0;
  66
  67         /* Write to the SOFTRESET bit */
  68         omap_hwmod_softreset(oh);
  69
  70         /* Enable the MSDI core and internal clock */
  71         v |= MSDI_CON_POW_MASK;
  72         v |= MSDI_TARGET_RESET_CLKD << MSDI_CON_CLKD_SHIFT;
  73         omap_hwmod_write(v, oh, MSDI_CON_OFFSET);
  74
  75         /* Poll on RESETDONE bit */
  76         omap_test_timeout((omap_hwmod_read(oh, oh->class->sysc->syss_offs)
  77                            & SYSS_RESETDONE_MASK),
  78                           MAX_MODULE_SOFTRESET_WAIT, c);
  79
  80         if (c == MAX_MODULE_SOFTRESET_WAIT)
  81                 pr_warning("%s: %s: softreset failed (waited %d usec)\n",
  82                            __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
  83         else
  84                 pr_debug("%s: %s: softreset in %d usec\n", __func__,
  85                          oh->name, c);
  86
  87         /* Disable the MSDI internal clock */
  88         v &= ~MSDI_CON_CLKD_MASK;
  89         omap_hwmod_write(v, oh, MSDI_CON_OFFSET);
  90
  91         return 0;
  92 }
  93
  94 #if defined(CONFIG_MMC_OMAP) || defined(CONFIG_MMC_OMAP_MODULE)
  95
  96 static inline void omap242x_mmc_mux(struct omap_mmc_platform_data
  97                                     *mmc_controller)
  98 {
  99         if ((mmc_controller->slots[0].switch_pin > 0) && \
 100                 (mmc_controller->slots[0].switch_pin < OMAP_MAX_GPIO_LINES))
 101                 omap_mux_init_gpio(mmc_controller->slots[0].switch_pin,
 102                                         OMAP_PIN_INPUT_PULLUP);
 103         if ((mmc_controller->slots[0].gpio_wp > 0) && \
 104                 (mmc_controller->slots[0].gpio_wp < OMAP_MAX_GPIO_LINES))
 105                 omap_mux_init_gpio(mmc_controller->slots[0].gpio_wp,
 106                                         OMAP_PIN_INPUT_PULLUP);
 107
 108         omap_mux_init_signal("sdmmc_cmd", 0);
 109         omap_mux_init_signal("sdmmc_clki", 0);
 110         omap_mux_init_signal("sdmmc_clko", 0);
 111         omap_mux_init_signal("sdmmc_dat0", 0);
 112         omap_mux_init_signal("sdmmc_dat_dir0", 0);
 113         omap_mux_init_signal("sdmmc_cmd_dir", 0);
 114         if (mmc_controller->slots[0].caps & MMC_CAP_4_BIT_DATA) {
 115                 omap_mux_init_signal("sdmmc_dat1", 0);
 116                 omap_mux_init_signal("sdmmc_dat2", 0);
 117                 omap_mux_init_signal("sdmmc_dat3", 0);
 118                 omap_mux_init_signal("sdmmc_dat_dir1", 0);
 119                 omap_mux_init_signal("sdmmc_dat_dir2", 0);
 120                 omap_mux_init_signal("sdmmc_dat_dir3", 0);
 121         }
 122
 123         /*
 124          * Use internal loop-back in MMC/SDIO Module Input Clock
 125          * selection
 126          */
 127         if (mmc_controller->slots[0].internal_clock) {
 128                 u32 v = omap_ctrl_readl(OMAP2_CONTROL_DEVCONF0);
 129                 v |= (1 << 24);
 130                 omap_ctrl_writel(v, OMAP2_CONTROL_DEVCONF0);
 131         }
 132 }
 133
 134 void __init omap242x_init_mmc(struct omap_mmc_platform_data **mmc_data)
 135 {
 136         struct platform_device *pdev;
 137         struct omap_hwmod *oh;
 138         int id = 0;
 139         char *oh_name = "msdi1";
 140         char *dev_name = "mmci-omap";
 141
 142         if (!mmc_data[0]) {
 143                 pr_err("%s fails: Incomplete platform data\n", __func__);
 144                 return;
 145         }
 146
 147         omap242x_mmc_mux(mmc_data[0]);
 148
 149         oh = omap_hwmod_lookup(oh_name);
 150         if (!oh) {
 151                 pr_err("Could not look up %s\n", oh_name);
 152                 return;
 153         }
 154         pdev = omap_device_build(dev_name, id, oh, mmc_data[0],
 155                                  sizeof(struct omap_mmc_platform_data), NULL, 0, 0);
 156         if (IS_ERR(pdev))
 157                 WARN(1, "Can'd build omap_device for %s:%s.\n",
 158                                         dev_name, oh->name);
 159 }
 160
 161 #endif