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