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 <dm.h>
41 #include <log.h>
42 #include <malloc.h>
43 #include <memalign.h>
44 #include <sdhci.h>
45 #include <time.h>
46 #include <asm/arch/msg.h>
47 #include <asm/arch/mbox.h>
48 #include <mach/sdhci.h>
49 #include <mach/timer.h>
50
51 /* 400KHz is max freq for card ID etc. Use that as min */
52 #define MIN_FREQ 400000
53 #define SDHCI_BUFFER 0x20
54
55 struct bcm2835_sdhci_plat {
56 struct mmc_config cfg;
57 struct mmc mmc;
58 };
59
60 struct bcm2835_sdhci_host {
61 struct sdhci_host host;
62 uint twoticks_delay;
63 ulong last_write;
64 };
65
to_bcm(struct sdhci_host * host)66 static inline struct bcm2835_sdhci_host *to_bcm(struct sdhci_host *host)
67 {
68 return (struct bcm2835_sdhci_host *)host;
69 }
70
bcm2835_sdhci_raw_writel(struct sdhci_host * host,u32 val,int reg)71 static inline void bcm2835_sdhci_raw_writel(struct sdhci_host *host, u32 val,
72 int reg)
73 {
74 struct bcm2835_sdhci_host *bcm_host = to_bcm(host);
75
76 /*
77 * The Arasan has a bugette whereby it may lose the content of
78 * successive writes to registers that are within two SD-card clock
79 * cycles of each other (a clock domain crossing problem).
80 * It seems, however, that the data register does not have this problem.
81 * (Which is just as well - otherwise we'd have to nobble the DMA engine
82 * too)
83 */
84 if (reg != SDHCI_BUFFER) {
85 while (timer_get_us() - bcm_host->last_write <
86 bcm_host->twoticks_delay)
87 ;
88 }
89
90 writel(val, host->ioaddr + reg);
91 bcm_host->last_write = timer_get_us();
92 }
93
bcm2835_sdhci_raw_readl(struct sdhci_host * host,int reg)94 static inline u32 bcm2835_sdhci_raw_readl(struct sdhci_host *host, int reg)
95 {
96 return readl(host->ioaddr + reg);
97 }
98
bcm2835_sdhci_writel(struct sdhci_host * host,u32 val,int reg)99 static void bcm2835_sdhci_writel(struct sdhci_host *host, u32 val, int reg)
100 {
101 bcm2835_sdhci_raw_writel(host, val, reg);
102 }
103
bcm2835_sdhci_writew(struct sdhci_host * host,u16 val,int reg)104 static void bcm2835_sdhci_writew(struct sdhci_host *host, u16 val, int reg)
105 {
106 static u32 shadow;
107 u32 oldval = (reg == SDHCI_COMMAND) ? shadow :
108 bcm2835_sdhci_raw_readl(host, reg & ~3);
109 u32 word_num = (reg >> 1) & 1;
110 u32 word_shift = word_num * 16;
111 u32 mask = 0xffff << word_shift;
112 u32 newval = (oldval & ~mask) | (val << word_shift);
113
114 if (reg == SDHCI_TRANSFER_MODE)
115 shadow = newval;
116 else
117 bcm2835_sdhci_raw_writel(host, newval, reg & ~3);
118 }
119
bcm2835_sdhci_writeb(struct sdhci_host * host,u8 val,int reg)120 static void bcm2835_sdhci_writeb(struct sdhci_host *host, u8 val, int reg)
121 {
122 u32 oldval = bcm2835_sdhci_raw_readl(host, reg & ~3);
123 u32 byte_num = reg & 3;
124 u32 byte_shift = byte_num * 8;
125 u32 mask = 0xff << byte_shift;
126 u32 newval = (oldval & ~mask) | (val << byte_shift);
127
128 bcm2835_sdhci_raw_writel(host, newval, reg & ~3);
129 }
130
bcm2835_sdhci_readl(struct sdhci_host * host,int reg)131 static u32 bcm2835_sdhci_readl(struct sdhci_host *host, int reg)
132 {
133 u32 val = bcm2835_sdhci_raw_readl(host, reg);
134
135 return val;
136 }
137
bcm2835_sdhci_readw(struct sdhci_host * host,int reg)138 static u16 bcm2835_sdhci_readw(struct sdhci_host *host, int reg)
139 {
140 u32 val = bcm2835_sdhci_raw_readl(host, (reg & ~3));
141 u32 word_num = (reg >> 1) & 1;
142 u32 word_shift = word_num * 16;
143 u32 word = (val >> word_shift) & 0xffff;
144
145 return word;
146 }
147
bcm2835_sdhci_readb(struct sdhci_host * host,int reg)148 static u8 bcm2835_sdhci_readb(struct sdhci_host *host, int reg)
149 {
150 u32 val = bcm2835_sdhci_raw_readl(host, (reg & ~3));
151 u32 byte_num = reg & 3;
152 u32 byte_shift = byte_num * 8;
153 u32 byte = (val >> byte_shift) & 0xff;
154
155 return byte;
156 }
157
158 static const struct sdhci_ops bcm2835_ops = {
159 .write_l = bcm2835_sdhci_writel,
160 .write_w = bcm2835_sdhci_writew,
161 .write_b = bcm2835_sdhci_writeb,
162 .read_l = bcm2835_sdhci_readl,
163 .read_w = bcm2835_sdhci_readw,
164 .read_b = bcm2835_sdhci_readb,
165 };
166
bcm2835_sdhci_bind(struct udevice * dev)167 static int bcm2835_sdhci_bind(struct udevice *dev)
168 {
169 struct bcm2835_sdhci_plat *plat = dev_get_plat(dev);
170
171 return sdhci_bind(dev, &plat->mmc, &plat->cfg);
172 }
173
bcm2835_sdhci_probe(struct udevice * dev)174 static int bcm2835_sdhci_probe(struct udevice *dev)
175 {
176 struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
177 struct bcm2835_sdhci_plat *plat = dev_get_plat(dev);
178 struct bcm2835_sdhci_host *priv = dev_get_priv(dev);
179 struct sdhci_host *host = &priv->host;
180 fdt_addr_t base;
181 int emmc_freq;
182 int ret;
183 int clock_id = (int)dev_get_driver_data(dev);
184
185 base = dev_read_addr(dev);
186 if (base == FDT_ADDR_T_NONE)
187 return -EINVAL;
188
189 ret = bcm2835_get_mmc_clock(clock_id);
190 if (ret < 0) {
191 debug("%s: Failed to set MMC clock (err=%d)\n", __func__, ret);
192 return ret;
193 }
194 emmc_freq = ret;
195
196 /*
197 * See the comments in bcm2835_sdhci_raw_writel().
198 *
199 * This should probably be dynamically calculated based on the actual
200 * frequency. However, this is the longest we'll have to wait, and
201 * doesn't seem to slow access down too much, so the added complexity
202 * doesn't seem worth it for now.
203 *
204 * 1/MIN_FREQ is (max) time per tick of eMMC clock.
205 * 2/MIN_FREQ is time for two ticks.
206 * Multiply by 1000000 to get uS per two ticks.
207 * +1 for hack rounding.
208 */
209 priv->twoticks_delay = ((2 * 1000000) / MIN_FREQ) + 1;
210 priv->last_write = 0;
211
212 host->name = dev->name;
213 host->ioaddr = (void *)(uintptr_t)base;
214 host->quirks = SDHCI_QUIRK_BROKEN_VOLTAGE | SDHCI_QUIRK_BROKEN_R1B |
215 SDHCI_QUIRK_WAIT_SEND_CMD | SDHCI_QUIRK_NO_HISPD_BIT;
216 host->max_clk = emmc_freq;
217 host->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
218 host->ops = &bcm2835_ops;
219
220 host->mmc = &plat->mmc;
221 host->mmc->dev = dev;
222
223 ret = sdhci_setup_cfg(&plat->cfg, host, emmc_freq, MIN_FREQ);
224 if (ret) {
225 debug("%s: Failed to setup SDHCI (err=%d)\n", __func__, ret);
226 return ret;
227 }
228
229 upriv->mmc = &plat->mmc;
230 host->mmc->priv = host;
231
232 return sdhci_probe(dev);
233 }
234
235 static const struct udevice_id bcm2835_sdhci_match[] = {
236 {
237 .compatible = "brcm,bcm2835-sdhci",
238 .data = BCM2835_MBOX_CLOCK_ID_EMMC
239 },
240 {
241 .compatible = "brcm,bcm2711-emmc2",
242 .data = BCM2835_MBOX_CLOCK_ID_EMMC2
243 },
244 { /* sentinel */ }
245 };
246
247 U_BOOT_DRIVER(sdhci_cdns) = {
248 .name = "sdhci-bcm2835",
249 .id = UCLASS_MMC,
250 .of_match = bcm2835_sdhci_match,
251 .bind = bcm2835_sdhci_bind,
252 .probe = bcm2835_sdhci_probe,
253 .priv_auto = sizeof(struct bcm2835_sdhci_host),
254 .plat_auto = sizeof(struct bcm2835_sdhci_plat),
255 .ops = &sdhci_ops,
256 };
257