path: root/drivers/mmc/host/bcm2835.c

// SPDX-License-Identifier: GPL-2.0
/*
 * bcm2835 sdhost driver.
 *
 * The 2835 has two SD controllers: The Arasan sdhci controller
 * (supported by the iproc driver) and a custom sdhost controller
 * (supported by this driver).
 *
 * The sdhci controller supports both sdcard and sdio.  The sdhost
 * controller supports the sdcard only, but has better performance.
 * Also note that the rpi3 has sdio wifi, so driving the sdcard with
 * the sdhost controller allows to use the sdhci controller for wifi
 * support.
 *
 * The configuration is done by devicetree via pin muxing.  Both
 * SD controller are available on the same pins (2 pin groups = pin 22
 * to 27 + pin 48 to 53).  So it's possible to use both SD controllers
 * at the same time with different pin groups.
 *
 * Author:      Phil Elwell <phil@raspberrypi.org>
 *              Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd.
 *
 * Based on
 *  mmc-bcm2835.c by Gellert Weisz
 * which is, in turn, based on
 *  sdhci-bcm2708.c by Broadcom
 *  sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko
 *  sdhci.c and sdhci-pci.c by Pierre Ossman
 */
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/scatterlist.h>
#include <linux/time.h>
#include <linux/workqueue.h>

#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sd.h>

#define SDCMD  0x00 /* Command to SD card              - 16 R/W */
#define SDARG  0x04 /* Argument to SD card             - 32 R/W */
#define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
#define SDCDIV 0x0c /* Start value for clock divider   - 11 R/W */
#define SDRSP0 0x10 /* SD card response (31:0)         - 32 R   */
#define SDRSP1 0x14 /* SD card response (63:32)        - 32 R   */
#define SDRSP2 0x18 /* SD card response (95:64)        - 32 R   */
#define SDRSP3 0x1c /* SD card response (127:96)       - 32 R   */
#define SDHSTS 0x20 /* SD host status                  - 11 R/W */
#define SDVDD  0x30 /* SD card power control           -  1 R/W */
#define SDEDM  0x34 /* Emergency Debug Mode            - 13 R/W */
#define SDHCFG 0x38 /* Host configuration              -  2 R/W */
#define SDHBCT 0x3c /* Host byte count (debug)         - 32 R/W */
#define SDDATA 0x40