245 lines
		
	
	
		
			6.7 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			245 lines
		
	
	
		
			6.7 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * This code was extracted from:
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|  * git://github.com/gonzoua/u-boot-pi.git master
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|  * and hence presumably (C) 2012 Oleksandr Tymoshenko
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|  *
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|  * Tweaks for U-Boot upstreaming
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|  * (C) 2012 Stephen Warren
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|  *
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|  * Portions (e.g. read/write macros, concepts for back-to-back register write
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|  * timing workarounds) obviously extracted from the Linux kernel at:
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|  * https://github.com/raspberrypi/linux.git rpi-3.6.y
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|  *
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|  * The Linux kernel code has the following (c) and license, which is hence
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|  * propagated to Oleksandr's tree and here:
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|  *
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|  * Support for SDHCI device on 2835
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|  * Based on sdhci-bcm2708.c (c) 2010 Broadcom
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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|  */
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| 
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| /* Supports:
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|  * SDHCI platform device - Arasan SD controller in BCM2708
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|  *
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|  * Inspired by sdhci-pci.c, by Pierre Ossman
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|  */
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| 
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| #include <common.h>
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| #include <dm.h>
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| #include <malloc.h>
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| #include <memalign.h>
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| #include <sdhci.h>
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| #include <asm/arch/msg.h>
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| #include <asm/arch/mbox.h>
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| #include <mach/sdhci.h>
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| #include <mach/timer.h>
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| 
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| /* 400KHz is max freq for card ID etc. Use that as min */
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| #define MIN_FREQ 400000
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| #define SDHCI_BUFFER 0x20
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| 
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| struct bcm2835_sdhci_plat {
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| 	struct mmc_config cfg;
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| 	struct mmc mmc;
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| };
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| 
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| struct bcm2835_sdhci_host {
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| 	struct sdhci_host host;
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| 	uint twoticks_delay;
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| 	ulong last_write;
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| };
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| 
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| static inline struct bcm2835_sdhci_host *to_bcm(struct sdhci_host *host)
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| {
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| 	return (struct bcm2835_sdhci_host *)host;
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| }
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| 
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| static inline void bcm2835_sdhci_raw_writel(struct sdhci_host *host, u32 val,
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| 					    int reg)
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| {
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| 	struct bcm2835_sdhci_host *bcm_host = to_bcm(host);
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| 
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| 	/*
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| 	 * The Arasan has a bugette whereby it may lose the content of
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| 	 * successive writes to registers that are within two SD-card clock
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| 	 * cycles of each other (a clock domain crossing problem).
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| 	 * It seems, however, that the data register does not have this problem.
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| 	 * (Which is just as well - otherwise we'd have to nobble the DMA engine
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| 	 * too)
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| 	 */
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| 	if (reg != SDHCI_BUFFER) {
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| 		while (timer_get_us() - bcm_host->last_write <
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| 		       bcm_host->twoticks_delay)
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| 			;
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| 	}
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| 
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| 	writel(val, host->ioaddr + reg);
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| 	bcm_host->last_write = timer_get_us();
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| }
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| 
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| static inline u32 bcm2835_sdhci_raw_readl(struct sdhci_host *host, int reg)
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| {
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| 	return readl(host->ioaddr + reg);
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| }
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| 
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| static void bcm2835_sdhci_writel(struct sdhci_host *host, u32 val, int reg)
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| {
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| 	bcm2835_sdhci_raw_writel(host, val, reg);
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| }
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| 
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| static void bcm2835_sdhci_writew(struct sdhci_host *host, u16 val, int reg)
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| {
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| 	static u32 shadow;
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| 	u32 oldval = (reg == SDHCI_COMMAND) ? shadow :
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| 		bcm2835_sdhci_raw_readl(host, reg & ~3);
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| 	u32 word_num = (reg >> 1) & 1;
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| 	u32 word_shift = word_num * 16;
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| 	u32 mask = 0xffff << word_shift;
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| 	u32 newval = (oldval & ~mask) | (val << word_shift);
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| 
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| 	if (reg == SDHCI_TRANSFER_MODE)
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| 		shadow = newval;
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| 	else
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| 		bcm2835_sdhci_raw_writel(host, newval, reg & ~3);
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| }
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| 
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| static void bcm2835_sdhci_writeb(struct sdhci_host *host, u8 val, int reg)
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| {
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| 	u32 oldval = bcm2835_sdhci_raw_readl(host, reg & ~3);
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| 	u32 byte_num = reg & 3;
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| 	u32 byte_shift = byte_num * 8;
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| 	u32 mask = 0xff << byte_shift;
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| 	u32 newval = (oldval & ~mask) | (val << byte_shift);
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| 
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| 	bcm2835_sdhci_raw_writel(host, newval, reg & ~3);
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| }
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| 
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| static u32 bcm2835_sdhci_readl(struct sdhci_host *host, int reg)
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| {
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| 	u32 val = bcm2835_sdhci_raw_readl(host, reg);
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| 
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| 	return val;
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| }
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| 
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| static u16 bcm2835_sdhci_readw(struct sdhci_host *host, int reg)
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| {
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| 	u32 val = bcm2835_sdhci_raw_readl(host, (reg & ~3));
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| 	u32 word_num = (reg >> 1) & 1;
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| 	u32 word_shift = word_num * 16;
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| 	u32 word = (val >> word_shift) & 0xffff;
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| 
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| 	return word;
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| }
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| 
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| static u8 bcm2835_sdhci_readb(struct sdhci_host *host, int reg)
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| {
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| 	u32 val = bcm2835_sdhci_raw_readl(host, (reg & ~3));
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| 	u32 byte_num = reg & 3;
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| 	u32 byte_shift = byte_num * 8;
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| 	u32 byte = (val >> byte_shift) & 0xff;
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| 
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| 	return byte;
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| }
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| 
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| static const struct sdhci_ops bcm2835_ops = {
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| 	.write_l = bcm2835_sdhci_writel,
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| 	.write_w = bcm2835_sdhci_writew,
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| 	.write_b = bcm2835_sdhci_writeb,
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| 	.read_l = bcm2835_sdhci_readl,
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| 	.read_w = bcm2835_sdhci_readw,
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| 	.read_b = bcm2835_sdhci_readb,
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| };
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| 
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| static int bcm2835_sdhci_bind(struct udevice *dev)
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| {
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| 	struct bcm2835_sdhci_plat *plat = dev_get_platdata(dev);
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| 
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| 	return sdhci_bind(dev, &plat->mmc, &plat->cfg);
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| }
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| 
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| static int bcm2835_sdhci_probe(struct udevice *dev)
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| {
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| 	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
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| 	struct bcm2835_sdhci_plat *plat = dev_get_platdata(dev);
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| 	struct bcm2835_sdhci_host *priv = dev_get_priv(dev);
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| 	struct sdhci_host *host = &priv->host;
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| 	fdt_addr_t base;
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| 	int emmc_freq;
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| 	int ret;
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| 
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| 	base = devfdt_get_addr(dev);
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| 	if (base == FDT_ADDR_T_NONE)
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| 		return -EINVAL;
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| 
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| 	ret = bcm2835_get_mmc_clock(BCM2835_MBOX_CLOCK_ID_EMMC);
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| 	if (ret < 0) {
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| 		debug("%s: Failed to set MMC clock (err=%d)\n", __func__, ret);
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| 		return ret;
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| 	}
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| 	emmc_freq = ret;
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| 
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| 	/*
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| 	 * See the comments in bcm2835_sdhci_raw_writel().
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| 	 *
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| 	 * This should probably be dynamically calculated based on the actual
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| 	 * frequency. However, this is the longest we'll have to wait, and
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| 	 * doesn't seem to slow access down too much, so the added complexity
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| 	 * doesn't seem worth it for now.
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| 	 *
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| 	 * 1/MIN_FREQ is (max) time per tick of eMMC clock.
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| 	 * 2/MIN_FREQ is time for two ticks.
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| 	 * Multiply by 1000000 to get uS per two ticks.
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| 	 * +1 for hack rounding.
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| 	 */
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| 	priv->twoticks_delay = ((2 * 1000000) / MIN_FREQ) + 1;
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| 	priv->last_write = 0;
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| 
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| 	host->name = dev->name;
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| 	host->ioaddr = (void *)base;
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| 	host->quirks = SDHCI_QUIRK_BROKEN_VOLTAGE | SDHCI_QUIRK_BROKEN_R1B |
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| 		SDHCI_QUIRK_WAIT_SEND_CMD | SDHCI_QUIRK_NO_HISPD_BIT;
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| 	host->max_clk = emmc_freq;
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| 	host->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
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| 	host->ops = &bcm2835_ops;
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| 
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| 	ret = sdhci_setup_cfg(&plat->cfg, host, emmc_freq, MIN_FREQ);
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| 	if (ret) {
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| 		debug("%s: Failed to setup SDHCI (err=%d)\n", __func__, ret);
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| 		return ret;
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| 	}
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| 
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| 	upriv->mmc = &plat->mmc;
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| 	host->mmc = &plat->mmc;
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| 	host->mmc->priv = host;
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| 
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| 	return sdhci_probe(dev);
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| }
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| 
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| static const struct udevice_id bcm2835_sdhci_match[] = {
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| 	{ .compatible = "brcm,bcm2835-sdhci" },
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| 	{ /* sentinel */ }
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| };
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| 
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| U_BOOT_DRIVER(sdhci_cdns) = {
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| 	.name = "sdhci-bcm2835",
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| 	.id = UCLASS_MMC,
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| 	.of_match = bcm2835_sdhci_match,
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| 	.bind = bcm2835_sdhci_bind,
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| 	.probe = bcm2835_sdhci_probe,
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| 	.priv_auto_alloc_size = sizeof(struct bcm2835_sdhci_host),
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| 	.platdata_auto_alloc_size = sizeof(struct bcm2835_sdhci_plat),
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| 	.ops = &sdhci_ops,
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| };
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