linux/drivers/mmc/host/sdhci-iproc.c

264 lines
7.4 KiB
C

/*
* Copyright (C) 2014 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/*
* iProc SDHCI platform driver
*/
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/mmc/host.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include "sdhci-pltfm.h"
struct sdhci_iproc_data {
const struct sdhci_pltfm_data *pdata;
u32 caps;
u32 caps1;
u32 mmc_caps;
};
struct sdhci_iproc_host {
const struct sdhci_iproc_data *data;
u32 shadow_cmd;
u32 shadow_blk;
};
#define REG_OFFSET_IN_BITS(reg) ((reg) << 3 & 0x18)
static inline u32 sdhci_iproc_readl(struct sdhci_host *host, int reg)
{
u32 val = readl(host->ioaddr + reg);
pr_debug("%s: readl [0x%02x] 0x%08x\n",
mmc_hostname(host->mmc), reg, val);
return val;
}
static u16 sdhci_iproc_readw(struct sdhci_host *host, int reg)
{
u32 val = sdhci_iproc_readl(host, (reg & ~3));
u16 word = val >> REG_OFFSET_IN_BITS(reg) & 0xffff;
return word;
}
static u8 sdhci_iproc_readb(struct sdhci_host *host, int reg)
{
u32 val = sdhci_iproc_readl(host, (reg & ~3));
u8 byte = val >> REG_OFFSET_IN_BITS(reg) & 0xff;
return byte;
}
static inline void sdhci_iproc_writel(struct sdhci_host *host, u32 val, int reg)
{
pr_debug("%s: writel [0x%02x] 0x%08x\n",
mmc_hostname(host->mmc), reg, val);
writel(val, host->ioaddr + reg);
if (host->clock <= 400000) {
/* Round up to micro-second four SD clock delay */
if (host->clock)
udelay((4 * 1000000 + host->clock - 1) / host->clock);
else
udelay(10);
}
}
/*
* The Arasan has a bugette whereby it may lose the content of successive
* writes to the same register that are within two SD-card clock cycles of
* each other (a clock domain crossing problem). The data
* register does not have this problem, which is just as well - otherwise we'd
* have to nobble the DMA engine too.
*
* This wouldn't be a problem with the code except that we can only write the
* controller with 32-bit writes. So two different 16-bit registers are
* written back to back creates the problem.
*
* In reality, this only happens when SDHCI_BLOCK_SIZE and SDHCI_BLOCK_COUNT
* are written followed by SDHCI_TRANSFER_MODE and SDHCI_COMMAND.
* The BLOCK_SIZE and BLOCK_COUNT are meaningless until a command issued so
* the work around can be further optimized. We can keep shadow values of
* BLOCK_SIZE, BLOCK_COUNT, and TRANSFER_MODE until a COMMAND is issued.
* Then, write the BLOCK_SIZE+BLOCK_COUNT in a single 32-bit write followed
* by the TRANSFER+COMMAND in another 32-bit write.
*/
static void sdhci_iproc_writew(struct sdhci_host *host, u16 val, int reg)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_iproc_host *iproc_host = sdhci_pltfm_priv(pltfm_host);
u32 word_shift = REG_OFFSET_IN_BITS(reg);
u32 mask = 0xffff << word_shift;
u32 oldval, newval;
if (reg == SDHCI_COMMAND) {
/* Write the block now as we are issuing a command */
if (iproc_host->shadow_blk != 0) {
sdhci_iproc_writel(host, iproc_host->shadow_blk,
SDHCI_BLOCK_SIZE);
iproc_host->shadow_blk = 0;
}
oldval = iproc_host->shadow_cmd;
} else if (reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) {
/* Block size and count are stored in shadow reg */
oldval = iproc_host->shadow_blk;
} else {
/* Read reg, all other registers are not shadowed */
oldval = sdhci_iproc_readl(host, (reg & ~3));
}
newval = (oldval & ~mask) | (val << word_shift);
if (reg == SDHCI_TRANSFER_MODE) {
/* Save the transfer mode until the command is issued */
iproc_host->shadow_cmd = newval;
} else if (reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) {
/* Save the block info until the command is issued */
iproc_host->shadow_blk = newval;
} else {
/* Command or other regular 32-bit write */
sdhci_iproc_writel(host, newval, reg & ~3);
}
}
static void sdhci_iproc_writeb(struct sdhci_host *host, u8 val, int reg)
{
u32 oldval = sdhci_iproc_readl(host, (reg & ~3));
u32 byte_shift = REG_OFFSET_IN_BITS(reg);
u32 mask = 0xff << byte_shift;
u32 newval = (oldval & ~mask) | (val << byte_shift);
sdhci_iproc_writel(host, newval, reg & ~3);
}
static const struct sdhci_ops sdhci_iproc_ops = {
.read_l = sdhci_iproc_readl,
.read_w = sdhci_iproc_readw,
.read_b = sdhci_iproc_readb,
.write_l = sdhci_iproc_writel,
.write_w = sdhci_iproc_writew,
.write_b = sdhci_iproc_writeb,
.set_clock = sdhci_set_clock,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
.set_bus_width = sdhci_set_bus_width,
.reset = sdhci_reset,
.set_uhs_signaling = sdhci_set_uhs_signaling,
};
static const struct sdhci_pltfm_data sdhci_iproc_pltfm_data = {
.quirks = SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK,
.quirks2 = SDHCI_QUIRK2_ACMD23_BROKEN,
.ops = &sdhci_iproc_ops,
};
static const struct sdhci_iproc_data iproc_data = {
.pdata = &sdhci_iproc_pltfm_data,
.caps = 0x05E90000,
.caps1 = 0x00000064,
.mmc_caps = MMC_CAP_1_8V_DDR,
};
static const struct sdhci_pltfm_data sdhci_bcm2835_pltfm_data = {
.quirks = SDHCI_QUIRK_BROKEN_CARD_DETECTION |
SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
SDHCI_QUIRK_MISSING_CAPS,
.ops = &sdhci_iproc_ops,
};
static const struct sdhci_iproc_data bcm2835_data = {
.pdata = &sdhci_bcm2835_pltfm_data,
.caps = SDHCI_CAN_VDD_330,
.caps1 = 0x00000000,
.mmc_caps = 0x00000000,
};
static const struct of_device_id sdhci_iproc_of_match[] = {
{ .compatible = "brcm,bcm2835-sdhci", .data = &bcm2835_data },
{ .compatible = "brcm,sdhci-iproc-cygnus", .data = &iproc_data },
{ }
};
MODULE_DEVICE_TABLE(of, sdhci_iproc_of_match);
static int sdhci_iproc_probe(struct platform_device *pdev)
{
const struct of_device_id *match;
const struct sdhci_iproc_data *iproc_data;
struct sdhci_host *host;
struct sdhci_iproc_host *iproc_host;
struct sdhci_pltfm_host *pltfm_host;
int ret;
match = of_match_device(sdhci_iproc_of_match, &pdev->dev);
if (!match)
return -EINVAL;
iproc_data = match->data;
host = sdhci_pltfm_init(pdev, iproc_data->pdata, sizeof(*iproc_host));
if (IS_ERR(host))
return PTR_ERR(host);
pltfm_host = sdhci_priv(host);
iproc_host = sdhci_pltfm_priv(pltfm_host);
iproc_host->data = iproc_data;
mmc_of_parse(host->mmc);
sdhci_get_of_property(pdev);
host->mmc->caps |= iproc_host->data->mmc_caps;
pltfm_host->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(pltfm_host->clk)) {
ret = PTR_ERR(pltfm_host->clk);
goto err;
}
ret = clk_prepare_enable(pltfm_host->clk);
if (ret) {
dev_err(&pdev->dev, "failed to enable host clk\n");
goto err;
}
if (iproc_host->data->pdata->quirks & SDHCI_QUIRK_MISSING_CAPS) {
host->caps = iproc_host->data->caps;
host->caps1 = iproc_host->data->caps1;
}
ret = sdhci_add_host(host);
if (ret)
goto err_clk;
return 0;
err_clk:
clk_disable_unprepare(pltfm_host->clk);
err:
sdhci_pltfm_free(pdev);
return ret;
}
static struct platform_driver sdhci_iproc_driver = {
.driver = {
.name = "sdhci-iproc",
.of_match_table = sdhci_iproc_of_match,
.pm = SDHCI_PLTFM_PMOPS,
},
.probe = sdhci_iproc_probe,
.remove = sdhci_pltfm_unregister,
};
module_platform_driver(sdhci_iproc_driver);
MODULE_AUTHOR("Broadcom");
MODULE_DESCRIPTION("IPROC SDHCI driver");
MODULE_LICENSE("GPL v2");