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Stephen Warren9a4fbe42013-01-29 16:37:41 +00001/*
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>
Masahiro Yamadad6c418e2015-03-19 19:42:57 +090042#include <mach/timer.h>
43#include <mach/sdhci.h>
Stephen Warren9a4fbe42013-01-29 16:37:41 +000044
45/* 400KHz is max freq for card ID etc. Use that as min */
46#define MIN_FREQ 400000
47
48struct bcm2835_sdhci_host {
49 struct sdhci_host host;
50 uint twoticks_delay;
51 ulong last_write;
52};
53
54static inline struct bcm2835_sdhci_host *to_bcm(struct sdhci_host *host)
55{
56 return (struct bcm2835_sdhci_host *)host;
57}
58
59static 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 */
Stephen Warren5eaa2152013-03-27 18:43:23 +000072 while (get_timer_us(bcm_host->last_write) < bcm_host->twoticks_delay)
Stephen Warren9a4fbe42013-01-29 16:37:41 +000073 ;
74
75 writel(val, host->ioaddr + reg);
Stephen Warren5eaa2152013-03-27 18:43:23 +000076 bcm_host->last_write = get_timer_us(0);
Stephen Warren9a4fbe42013-01-29 16:37:41 +000077}
78
79static inline u32 bcm2835_sdhci_raw_readl(struct sdhci_host *host, int reg)
80{
81 return readl(host->ioaddr + reg);
82}
83
84static void bcm2835_sdhci_writel(struct sdhci_host *host, u32 val, int reg)
85{
86 bcm2835_sdhci_raw_writel(host, val, reg);
87}
88
89static 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
105static 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
116static 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
123static 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
133static 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
143static 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
152int bcm2835_sdhci_init(u32 regbase, u32 emmc_freq)
153{
154 struct bcm2835_sdhci_host *bcm_host;
155 struct sdhci_host *host;
156
157 bcm_host = malloc(sizeof(*bcm_host));
158 if (!bcm_host) {
159 printf("sdhci_host malloc fail!\n");
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 |
Lubomir Rintel64973022014-06-10 20:46:43 +0200183 SDHCI_QUIRK_WAIT_SEND_CMD | SDHCI_QUIRK_NO_HISPD_BIT;
Stephen Warren9a4fbe42013-01-29 16:37:41 +0000184 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}