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 <plat/omap_hwmod.h> 29 #include <plat/omap_device.h> 30 #include <plat/mmc.h> 31 32 #include "common.h" 33 #include "control.h" 34 #include "mux.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 /* Maximum microseconds to wait for OMAP module to softreset */ 48 #define MAX_MODULE_SOFTRESET_WAIT 10000 49 50 /* MSDI_TARGET_RESET_CLKD: clock divisor to use throughout the reset */ 51 #define MSDI_TARGET_RESET_CLKD 0x3ff 52 53 /** 54 * omap_msdi_reset - reset the MSDI IP block 55 * @oh: struct omap_hwmod * 56 * 57 * The MSDI IP block on OMAP2420 has to have both the POW and CLKD 58 * fields set inside its CON register for a reset to complete 59 * successfully. This is not documented in the TRM. For CLKD, we use 60 * the value that results in the lowest possible clock rate, to attempt 61 * to avoid disturbing any cards. 62 */ 63 int omap_msdi_reset(struct omap_hwmod *oh) 64 { 65 u16 v = 0; 66 int c = 0; 67 68 /* Write to the SOFTRESET bit */ 69 omap_hwmod_softreset(oh); 70 71 /* Enable the MSDI core and internal clock */ 72 v |= MSDI_CON_POW_MASK; 73 v |= MSDI_TARGET_RESET_CLKD << MSDI_CON_CLKD_SHIFT; 74 omap_hwmod_write(v, oh, MSDI_CON_OFFSET); 75 76 /* Poll on RESETDONE bit */ 77 omap_test_timeout((omap_hwmod_read(oh, oh->class->sysc->syss_offs) 78 & SYSS_RESETDONE_MASK), 79 MAX_MODULE_SOFTRESET_WAIT, c); 80 81 if (c == MAX_MODULE_SOFTRESET_WAIT) 82 pr_warning("%s: %s: softreset failed (waited %d usec)\n", 83 __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT); 84 else 85 pr_debug("%s: %s: softreset in %d usec\n", __func__, 86 oh->name, c); 87 88 /* Disable the MSDI internal clock */ 89 v &= ~MSDI_CON_CLKD_MASK; 90 omap_hwmod_write(v, oh, MSDI_CON_OFFSET); 91 92 return 0; 93 } 94 95 #if defined(CONFIG_MMC_OMAP) || defined(CONFIG_MMC_OMAP_MODULE) 96 97 static inline void omap242x_mmc_mux(struct omap_mmc_platform_data 98 *mmc_controller) 99 { 100 if ((mmc_controller->slots[0].switch_pin > 0) && \ 101 (mmc_controller->slots[0].switch_pin < OMAP_MAX_GPIO_LINES)) 102 omap_mux_init_gpio(mmc_controller->slots[0].switch_pin, 103 OMAP_PIN_INPUT_PULLUP); 104 if ((mmc_controller->slots[0].gpio_wp > 0) && \ 105 (mmc_controller->slots[0].gpio_wp < OMAP_MAX_GPIO_LINES)) 106 omap_mux_init_gpio(mmc_controller->slots[0].gpio_wp, 107 OMAP_PIN_INPUT_PULLUP); 108 109 omap_mux_init_signal("sdmmc_cmd", 0); 110 omap_mux_init_signal("sdmmc_clki", 0); 111 omap_mux_init_signal("sdmmc_clko", 0); 112 omap_mux_init_signal("sdmmc_dat0", 0); 113 omap_mux_init_signal("sdmmc_dat_dir0", 0); 114 omap_mux_init_signal("sdmmc_cmd_dir", 0); 115 if (mmc_controller->slots[0].caps & MMC_CAP_4_BIT_DATA) { 116 omap_mux_init_signal("sdmmc_dat1", 0); 117 omap_mux_init_signal("sdmmc_dat2", 0); 118 omap_mux_init_signal("sdmmc_dat3", 0); 119 omap_mux_init_signal("sdmmc_dat_dir1", 0); 120 omap_mux_init_signal("sdmmc_dat_dir2", 0); 121 omap_mux_init_signal("sdmmc_dat_dir3", 0); 122 } 123 124 /* 125 * Use internal loop-back in MMC/SDIO Module Input Clock 126 * selection 127 */ 128 if (mmc_controller->slots[0].internal_clock) { 129 u32 v = omap_ctrl_readl(OMAP2_CONTROL_DEVCONF0); 130 v |= (1 << 24); 131 omap_ctrl_writel(v, OMAP2_CONTROL_DEVCONF0); 132 } 133 } 134 135 void __init omap242x_init_mmc(struct omap_mmc_platform_data **mmc_data) 136 { 137 struct platform_device *pdev; 138 struct omap_hwmod *oh; 139 int id = 0; 140 char *oh_name = "msdi1"; 141 char *dev_name = "mmci-omap"; 142 143 if (!mmc_data[0]) { 144 pr_err("%s fails: Incomplete platform data\n", __func__); 145 return; 146 } 147 148 omap242x_mmc_mux(mmc_data[0]); 149 150 oh = omap_hwmod_lookup(oh_name); 151 if (!oh) { 152 pr_err("Could not look up %s\n", oh_name); 153 return; 154 } 155 pdev = omap_device_build(dev_name, id, oh, mmc_data[0], 156 sizeof(struct omap_mmc_platform_data), NULL, 0, 0); 157 if (IS_ERR(pdev)) 158 WARN(1, "Can'd build omap_device for %s:%s.\n", 159 dev_name, oh->name); 160 } 161 162 #endif 163