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9a4fbe4f SW |
1 | /* |
2 | * This code was extracted from: | |
3 | * git://github.com/gonzoua/u-boot-pi.git master | |
4 | * and hence presumably (C) 2012 Oleksandr Tymoshenko | |
5 | * | |
6 | * Tweaks for U-Boot upstreaming | |
7 | * (C) 2012 Stephen Warren | |
8 | * | |
9 | * Portions (e.g. read/write macros, concepts for back-to-back register write | |
10 | * timing workarounds) obviously extracted from the Linux kernel at: | |
11 | * https://github.com/raspberrypi/linux.git rpi-3.6.y | |
12 | * | |
13 | * The Linux kernel code has the following (c) and license, which is hence | |
14 | * propagated to Oleksandr's tree and here: | |
15 | * | |
16 | * Support for SDHCI device on 2835 | |
17 | * Based on sdhci-bcm2708.c (c) 2010 Broadcom | |
18 | * | |
19 | * This program is free software; you can redistribute it and/or modify | |
20 | * it under the terms of the GNU General Public License version 2 as | |
21 | * published by the Free Software Foundation. | |
22 | * | |
23 | * This program is distributed in the hope that it will be useful, | |
24 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
25 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
26 | * GNU General Public License for more details. | |
27 | * | |
28 | * You should have received a copy of the GNU General Public License | |
29 | * along with this program; if not, write to the Free Software | |
30 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
31 | */ | |
32 | ||
33 | /* Supports: | |
34 | * SDHCI platform device - Arasan SD controller in BCM2708 | |
35 | * | |
36 | * Inspired by sdhci-pci.c, by Pierre Ossman | |
37 | */ | |
38 | ||
39 | #include <common.h> | |
40 | #include <malloc.h> | |
41 | #include <sdhci.h> | |
d6c418e4 MY |
42 | #include <mach/timer.h> |
43 | #include <mach/sdhci.h> | |
9a4fbe4f SW |
44 | |
45 | /* 400KHz is max freq for card ID etc. Use that as min */ | |
46 | #define MIN_FREQ 400000 | |
47 | ||
48 | struct bcm2835_sdhci_host { | |
49 | struct sdhci_host host; | |
50 | uint twoticks_delay; | |
51 | ulong last_write; | |
52 | }; | |
53 | ||
54 | static inline struct bcm2835_sdhci_host *to_bcm(struct sdhci_host *host) | |
55 | { | |
56 | return (struct bcm2835_sdhci_host *)host; | |
57 | } | |
58 | ||
59 | static inline void bcm2835_sdhci_raw_writel(struct sdhci_host *host, u32 val, | |
60 | int reg) | |
61 | { | |
62 | struct bcm2835_sdhci_host *bcm_host = to_bcm(host); | |
63 | ||
64 | /* | |
65 | * The Arasan has a bugette whereby it may lose the content of | |
66 | * successive writes to registers that are within two SD-card clock | |
67 | * cycles of each other (a clock domain crossing problem). | |
68 | * It seems, however, that the data register does not have this problem. | |
69 | * (Which is just as well - otherwise we'd have to nobble the DMA engine | |
70 | * too) | |
71 | */ | |
9f1b4456 | 72 | while (timer_get_us() - bcm_host->last_write < bcm_host->twoticks_delay) |
9a4fbe4f SW |
73 | ; |
74 | ||
75 | writel(val, host->ioaddr + reg); | |
9f1b4456 | 76 | bcm_host->last_write = timer_get_us(); |
9a4fbe4f SW |
77 | } |
78 | ||
79 | static inline u32 bcm2835_sdhci_raw_readl(struct sdhci_host *host, int reg) | |
80 | { | |
81 | return readl(host->ioaddr + reg); | |
82 | } | |
83 | ||
84 | static void bcm2835_sdhci_writel(struct sdhci_host *host, u32 val, int reg) | |
85 | { | |
86 | bcm2835_sdhci_raw_writel(host, val, reg); | |
87 | } | |
88 | ||
89 | static void bcm2835_sdhci_writew(struct sdhci_host *host, u16 val, int reg) | |
90 | { | |
91 | static u32 shadow; | |
92 | u32 oldval = (reg == SDHCI_COMMAND) ? shadow : | |
93 | bcm2835_sdhci_raw_readl(host, reg & ~3); | |
94 | u32 word_num = (reg >> 1) & 1; | |
95 | u32 word_shift = word_num * 16; | |
96 | u32 mask = 0xffff << word_shift; | |
97 | u32 newval = (oldval & ~mask) | (val << word_shift); | |
98 | ||
99 | if (reg == SDHCI_TRANSFER_MODE) | |
100 | shadow = newval; | |
101 | else | |
102 | bcm2835_sdhci_raw_writel(host, newval, reg & ~3); | |
103 | } | |
104 | ||
105 | static void bcm2835_sdhci_writeb(struct sdhci_host *host, u8 val, int reg) | |
106 | { | |
107 | u32 oldval = bcm2835_sdhci_raw_readl(host, reg & ~3); | |
108 | u32 byte_num = reg & 3; | |
109 | u32 byte_shift = byte_num * 8; | |
110 | u32 mask = 0xff << byte_shift; | |
111 | u32 newval = (oldval & ~mask) | (val << byte_shift); | |
112 | ||
113 | bcm2835_sdhci_raw_writel(host, newval, reg & ~3); | |
114 | } | |
115 | ||
116 | static u32 bcm2835_sdhci_readl(struct sdhci_host *host, int reg) | |
117 | { | |
118 | u32 val = bcm2835_sdhci_raw_readl(host, reg); | |
119 | ||
120 | return val; | |
121 | } | |
122 | ||
123 | static u16 bcm2835_sdhci_readw(struct sdhci_host *host, int reg) | |
124 | { | |
125 | u32 val = bcm2835_sdhci_raw_readl(host, (reg & ~3)); | |
126 | u32 word_num = (reg >> 1) & 1; | |
127 | u32 word_shift = word_num * 16; | |
128 | u32 word = (val >> word_shift) & 0xffff; | |
129 | ||
130 | return word; | |
131 | } | |
132 | ||
133 | static u8 bcm2835_sdhci_readb(struct sdhci_host *host, int reg) | |
134 | { | |
135 | u32 val = bcm2835_sdhci_raw_readl(host, (reg & ~3)); | |
136 | u32 byte_num = reg & 3; | |
137 | u32 byte_shift = byte_num * 8; | |
138 | u32 byte = (val >> byte_shift) & 0xff; | |
139 | ||
140 | return byte; | |
141 | } | |
142 | ||
143 | static const struct sdhci_ops bcm2835_ops = { | |
144 | .write_l = bcm2835_sdhci_writel, | |
145 | .write_w = bcm2835_sdhci_writew, | |
146 | .write_b = bcm2835_sdhci_writeb, | |
147 | .read_l = bcm2835_sdhci_readl, | |
148 | .read_w = bcm2835_sdhci_readw, | |
149 | .read_b = bcm2835_sdhci_readb, | |
150 | }; | |
151 | ||
152 | int bcm2835_sdhci_init(u32 regbase, u32 emmc_freq) | |
153 | { | |
154 | struct bcm2835_sdhci_host *bcm_host; | |
155 | struct sdhci_host *host; | |
156 | ||
ebe78bb9 | 157 | bcm_host = calloc(1, sizeof(*bcm_host)); |
9a4fbe4f | 158 | if (!bcm_host) { |
ebe78bb9 | 159 | printf("sdhci_host calloc fail!\n"); |
9a4fbe4f SW |
160 | return 1; |
161 | } | |
162 | ||
163 | /* | |
164 | * See the comments in bcm2835_sdhci_raw_writel(). | |
165 | * | |
166 | * This should probably be dynamically calculated based on the actual | |
167 | * frequency. However, this is the longest we'll have to wait, and | |
168 | * doesn't seem to slow access down too much, so the added complexity | |
169 | * doesn't seem worth it for now. | |
170 | * | |
171 | * 1/MIN_FREQ is (max) time per tick of eMMC clock. | |
172 | * 2/MIN_FREQ is time for two ticks. | |
173 | * Multiply by 1000000 to get uS per two ticks. | |
174 | * +1 for hack rounding. | |
175 | */ | |
176 | bcm_host->twoticks_delay = ((2 * 1000000) / MIN_FREQ) + 1; | |
177 | bcm_host->last_write = 0; | |
178 | ||
179 | host = &bcm_host->host; | |
180 | host->name = "bcm2835_sdhci"; | |
181 | host->ioaddr = (void *)regbase; | |
182 | host->quirks = SDHCI_QUIRK_BROKEN_VOLTAGE | SDHCI_QUIRK_BROKEN_R1B | | |
64973023 | 183 | SDHCI_QUIRK_WAIT_SEND_CMD | SDHCI_QUIRK_NO_HISPD_BIT; |
9a4fbe4f SW |
184 | host->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195; |
185 | host->ops = &bcm2835_ops; | |
186 | ||
187 | host->version = sdhci_readw(host, SDHCI_HOST_VERSION); | |
188 | add_sdhci(host, emmc_freq, MIN_FREQ); | |
189 | ||
190 | return 0; | |
191 | } |