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linux/drivers/mmc/host/sdhci-cadence.c
Gustavo A. R. Silva 1a91a36aba mmc: Replace zero-length array with flexible-array member 
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20200226223125.GA20630@embeddedor
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2020-03-24 14:39:45 +01:00

468 lines
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 Socionext Inc.
* Author: Masahiro Yamada <yamada.masahiro@socionext.com>
*/
#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include "sdhci-pltfm.h"
/* HRS - Host Register Set (specific to Cadence) */
#define SDHCI_CDNS_HRS04 0x10 /* PHY access port */
#define SDHCI_CDNS_HRS04_ACK BIT(26)
#define SDHCI_CDNS_HRS04_RD BIT(25)
#define SDHCI_CDNS_HRS04_WR BIT(24)
#define SDHCI_CDNS_HRS04_RDATA GENMASK(23, 16)
#define SDHCI_CDNS_HRS04_WDATA GENMASK(15, 8)
#define SDHCI_CDNS_HRS04_ADDR GENMASK(5, 0)
#define SDHCI_CDNS_HRS06 0x18 /* eMMC control */
#define SDHCI_CDNS_HRS06_TUNE_UP BIT(15)
#define SDHCI_CDNS_HRS06_TUNE GENMASK(13, 8)
#define SDHCI_CDNS_HRS06_MODE GENMASK(2, 0)
#define SDHCI_CDNS_HRS06_MODE_SD 0x0
#define SDHCI_CDNS_HRS06_MODE_MMC_SDR 0x2
#define SDHCI_CDNS_HRS06_MODE_MMC_DDR 0x3
#define SDHCI_CDNS_HRS06_MODE_MMC_HS200 0x4
#define SDHCI_CDNS_HRS06_MODE_MMC_HS400 0x5
#define SDHCI_CDNS_HRS06_MODE_MMC_HS400ES 0x6
/* SRS - Slot Register Set (SDHCI-compatible) */
#define SDHCI_CDNS_SRS_BASE 0x200
/* PHY */
#define SDHCI_CDNS_PHY_DLY_SD_HS 0x00
#define SDHCI_CDNS_PHY_DLY_SD_DEFAULT 0x01
#define SDHCI_CDNS_PHY_DLY_UHS_SDR12 0x02
#define SDHCI_CDNS_PHY_DLY_UHS_SDR25 0x03
#define SDHCI_CDNS_PHY_DLY_UHS_SDR50 0x04
#define SDHCI_CDNS_PHY_DLY_UHS_DDR50 0x05
#define SDHCI_CDNS_PHY_DLY_EMMC_LEGACY 0x06
#define SDHCI_CDNS_PHY_DLY_EMMC_SDR 0x07
#define SDHCI_CDNS_PHY_DLY_EMMC_DDR 0x08
#define SDHCI_CDNS_PHY_DLY_SDCLK 0x0b
#define SDHCI_CDNS_PHY_DLY_HSMMC 0x0c
#define SDHCI_CDNS_PHY_DLY_STROBE 0x0d
/*
* The tuned val register is 6 bit-wide, but not the whole of the range is
* available. The range 0-42 seems to be available (then 43 wraps around to 0)
* but I am not quite sure if it is official. Use only 0 to 39 for safety.
*/
#define SDHCI_CDNS_MAX_TUNING_LOOP 40
struct sdhci_cdns_phy_param {
u8 addr;
u8 data;
};
struct sdhci_cdns_priv {
void __iomem *hrs_addr;
bool enhanced_strobe;
unsigned int nr_phy_params;
struct sdhci_cdns_phy_param phy_params[];
};
struct sdhci_cdns_phy_cfg {
const char *property;
u8 addr;
};
static const struct sdhci_cdns_phy_cfg sdhci_cdns_phy_cfgs[] = {
{ "cdns,phy-input-delay-sd-highspeed", SDHCI_CDNS_PHY_DLY_SD_HS, },
{ "cdns,phy-input-delay-legacy", SDHCI_CDNS_PHY_DLY_SD_DEFAULT, },
{ "cdns,phy-input-delay-sd-uhs-sdr12", SDHCI_CDNS_PHY_DLY_UHS_SDR12, },
{ "cdns,phy-input-delay-sd-uhs-sdr25", SDHCI_CDNS_PHY_DLY_UHS_SDR25, },
{ "cdns,phy-input-delay-sd-uhs-sdr50", SDHCI_CDNS_PHY_DLY_UHS_SDR50, },
{ "cdns,phy-input-delay-sd-uhs-ddr50", SDHCI_CDNS_PHY_DLY_UHS_DDR50, },
{ "cdns,phy-input-delay-mmc-highspeed", SDHCI_CDNS_PHY_DLY_EMMC_SDR, },
{ "cdns,phy-input-delay-mmc-ddr", SDHCI_CDNS_PHY_DLY_EMMC_DDR, },
{ "cdns,phy-dll-delay-sdclk", SDHCI_CDNS_PHY_DLY_SDCLK, },
{ "cdns,phy-dll-delay-sdclk-hsmmc", SDHCI_CDNS_PHY_DLY_HSMMC, },
{ "cdns,phy-dll-delay-strobe", SDHCI_CDNS_PHY_DLY_STROBE, },
};
static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
u8 addr, u8 data)
{
void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS04;
u32 tmp;
int ret;
tmp = FIELD_PREP(SDHCI_CDNS_HRS04_WDATA, data) |
FIELD_PREP(SDHCI_CDNS_HRS04_ADDR, addr);
writel(tmp, reg);
tmp |= SDHCI_CDNS_HRS04_WR;
writel(tmp, reg);
ret = readl_poll_timeout(reg, tmp, tmp & SDHCI_CDNS_HRS04_ACK, 0, 10);
if (ret)
return ret;
tmp &= ~SDHCI_CDNS_HRS04_WR;
writel(tmp, reg);
return 0;
}
static unsigned int sdhci_cdns_phy_param_count(struct device_node *np)
{
unsigned int count = 0;
int i;
for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++)
if (of_property_read_bool(np, sdhci_cdns_phy_cfgs[i].property))
count++;
return count;
}
static void sdhci_cdns_phy_param_parse(struct device_node *np,
struct sdhci_cdns_priv *priv)
{
struct sdhci_cdns_phy_param *p = priv->phy_params;
u32 val;
int ret, i;
for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++) {
ret = of_property_read_u32(np, sdhci_cdns_phy_cfgs[i].property,
&val);
if (ret)
continue;
p->addr = sdhci_cdns_phy_cfgs[i].addr;
p->data = val;
p++;
}
}
static int sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
{
int ret, i;
for (i = 0; i < priv->nr_phy_params; i++) {
ret = sdhci_cdns_write_phy_reg(priv, priv->phy_params[i].addr,
priv->phy_params[i].data);
if (ret)
return ret;
}
return 0;
}
static void *sdhci_cdns_priv(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
return sdhci_pltfm_priv(pltfm_host);
}
static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
{
/*
* Cadence's spec says the Timeout Clock Frequency is the same as the
* Base Clock Frequency.
*/
return host->max_clk;
}
static void sdhci_cdns_set_emmc_mode(struct sdhci_cdns_priv *priv, u32 mode)
{
u32 tmp;
/* The speed mode for eMMC is selected by HRS06 register */
tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
tmp &= ~SDHCI_CDNS_HRS06_MODE;
tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_MODE, mode);
writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
}
static u32 sdhci_cdns_get_emmc_mode(struct sdhci_cdns_priv *priv)
{
u32 tmp;
tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
return FIELD_GET(SDHCI_CDNS_HRS06_MODE, tmp);
}
static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
unsigned int timing)
{
struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
u32 mode;
switch (timing) {
case MMC_TIMING_MMC_HS:
mode = SDHCI_CDNS_HRS06_MODE_MMC_SDR;
break;
case MMC_TIMING_MMC_DDR52:
mode = SDHCI_CDNS_HRS06_MODE_MMC_DDR;
break;
case MMC_TIMING_MMC_HS200:
mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200;
break;
case MMC_TIMING_MMC_HS400:
if (priv->enhanced_strobe)
mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400ES;
else
mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
break;
default:
mode = SDHCI_CDNS_HRS06_MODE_SD;
break;
}
sdhci_cdns_set_emmc_mode(priv, mode);
/* For SD, fall back to the default handler */
if (mode == SDHCI_CDNS_HRS06_MODE_SD)
sdhci_set_uhs_signaling(host, timing);
}
static const struct sdhci_ops sdhci_cdns_ops = {
.set_clock = sdhci_set_clock,
.get_timeout_clock = sdhci_cdns_get_timeout_clock,
.set_bus_width = sdhci_set_bus_width,
.reset = sdhci_reset,
.set_uhs_signaling = sdhci_cdns_set_uhs_signaling,
};
static const struct sdhci_pltfm_data sdhci_cdns_uniphier_pltfm_data = {
.ops = &sdhci_cdns_ops,
.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
};
static const struct sdhci_pltfm_data sdhci_cdns_pltfm_data = {
.ops = &sdhci_cdns_ops,
};
static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val)
{
struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS06;
u32 tmp;
int i, ret;
if (WARN_ON(!FIELD_FIT(SDHCI_CDNS_HRS06_TUNE, val)))
return -EINVAL;
tmp = readl(reg);
tmp &= ~SDHCI_CDNS_HRS06_TUNE;
tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_TUNE, val);
/*
* Workaround for IP errata:
* The IP6116 SD/eMMC PHY design has a timing issue on receive data
* path. Send tune request twice.
*/
for (i = 0; i < 2; i++) {
tmp |= SDHCI_CDNS_HRS06_TUNE_UP;
writel(tmp, reg);
ret = readl_poll_timeout(reg, tmp,
!(tmp & SDHCI_CDNS_HRS06_TUNE_UP),
0, 1);
if (ret)
return ret;
}
return 0;
}
static int sdhci_cdns_execute_tuning(struct mmc_host *mmc, u32 opcode)
{
struct sdhci_host *host = mmc_priv(mmc);
int cur_streak = 0;
int max_streak = 0;
int end_of_streak = 0;
int i;
/*
* This handler only implements the eMMC tuning that is specific to
* this controller. Fall back to the standard method for SD timing.
*/
if (host->timing != MMC_TIMING_MMC_HS200)
return sdhci_execute_tuning(mmc, opcode);
if (WARN_ON(opcode != MMC_SEND_TUNING_BLOCK_HS200))
return -EINVAL;
for (i = 0; i < SDHCI_CDNS_MAX_TUNING_LOOP; i++) {
if (sdhci_cdns_set_tune_val(host, i) ||
mmc_send_tuning(host->mmc, opcode, NULL)) { /* bad */
cur_streak = 0;
} else { /* good */
cur_streak++;
if (cur_streak > max_streak) {
max_streak = cur_streak;
end_of_streak = i;
}
}
}
if (!max_streak) {
dev_err(mmc_dev(host->mmc), "no tuning point found\n");
return -EIO;
}
return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2);
}
static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
struct mmc_ios *ios)
{
struct sdhci_host *host = mmc_priv(mmc);
struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
u32 mode;
priv->enhanced_strobe = ios->enhanced_strobe;
mode = sdhci_cdns_get_emmc_mode(priv);
if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400 && ios->enhanced_strobe)
sdhci_cdns_set_emmc_mode(priv,
SDHCI_CDNS_HRS06_MODE_MMC_HS400ES);
if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400ES && !ios->enhanced_strobe)
sdhci_cdns_set_emmc_mode(priv,
SDHCI_CDNS_HRS06_MODE_MMC_HS400);
}
static int sdhci_cdns_probe(struct platform_device *pdev)
{
struct sdhci_host *host;
const struct sdhci_pltfm_data *data;
struct sdhci_pltfm_host *pltfm_host;
struct sdhci_cdns_priv *priv;
struct clk *clk;
unsigned int nr_phy_params;
int ret;
struct device *dev = &pdev->dev;
static const u16 version = SDHCI_SPEC_400 << SDHCI_SPEC_VER_SHIFT;
clk = devm_clk_get(dev, NULL);
if (IS_ERR(clk))
return PTR_ERR(clk);
ret = clk_prepare_enable(clk);
if (ret)
return ret;
data = of_device_get_match_data(dev);
if (!data)
data = &sdhci_cdns_pltfm_data;
nr_phy_params = sdhci_cdns_phy_param_count(dev->of_node);
host = sdhci_pltfm_init(pdev, data,
struct_size(priv, phy_params, nr_phy_params));
if (IS_ERR(host)) {
ret = PTR_ERR(host);
goto disable_clk;
}
pltfm_host = sdhci_priv(host);
pltfm_host->clk = clk;
priv = sdhci_pltfm_priv(pltfm_host);
priv->nr_phy_params = nr_phy_params;
priv->hrs_addr = host->ioaddr;
priv->enhanced_strobe = false;
host->ioaddr += SDHCI_CDNS_SRS_BASE;
host->mmc_host_ops.execute_tuning = sdhci_cdns_execute_tuning;
host->mmc_host_ops.hs400_enhanced_strobe =
sdhci_cdns_hs400_enhanced_strobe;
sdhci_enable_v4_mode(host);
__sdhci_read_caps(host, &version, NULL, NULL);
sdhci_get_of_property(pdev);
ret = mmc_of_parse(host->mmc);
if (ret)
goto free;
sdhci_cdns_phy_param_parse(dev->of_node, priv);
ret = sdhci_cdns_phy_init(priv);
if (ret)
goto free;
ret = sdhci_add_host(host);
if (ret)
goto free;
return 0;
free:
sdhci_pltfm_free(pdev);
disable_clk:
clk_disable_unprepare(clk);
return ret;
}
#ifdef CONFIG_PM_SLEEP
static int sdhci_cdns_resume(struct device *dev)
{
struct sdhci_host *host = dev_get_drvdata(dev);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_cdns_priv *priv = sdhci_pltfm_priv(pltfm_host);
int ret;
ret = clk_prepare_enable(pltfm_host->clk);
if (ret)
return ret;
ret = sdhci_cdns_phy_init(priv);
if (ret)
goto disable_clk;
ret = sdhci_resume_host(host);
if (ret)
goto disable_clk;
return 0;
disable_clk:
clk_disable_unprepare(pltfm_host->clk);
return ret;
}
#endif
static const struct dev_pm_ops sdhci_cdns_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(sdhci_pltfm_suspend, sdhci_cdns_resume)
};
static const struct of_device_id sdhci_cdns_match[] = {
{
.compatible = "socionext,uniphier-sd4hc",
.data = &sdhci_cdns_uniphier_pltfm_data,
},
{ .compatible = "cdns,sd4hc" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
static struct platform_driver sdhci_cdns_driver = {
.driver = {
.name = "sdhci-cdns",
.pm = &sdhci_cdns_pm_ops,
.of_match_table = sdhci_cdns_match,
},
.probe = sdhci_cdns_probe,
.remove = sdhci_pltfm_unregister,
};
module_platform_driver(sdhci_cdns_driver);
MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
MODULE_DESCRIPTION("Cadence SD/SDIO/eMMC Host Controller Driver");
MODULE_LICENSE("GPL");
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