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 */
omap_msdi_reset(struct omap_hwmod * oh)60 int 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
omap242x_mmc_mux(struct omap_mmc_platform_data * mmc_controller)94 static 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
omap242x_init_mmc(struct omap_mmc_platform_data ** mmc_data)132 void __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