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

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/*
* Copyright (C) 2016 Socionext Inc.
* Author: Masahiro Yamada <yamada.masahiro@socionext.com>
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/bitops.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/mmc/host.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_SHIFT 12
#define SDHCI_CDNS_HRS04_WDATA_SHIFT 8
#define SDHCI_CDNS_HRS04_ADDR_SHIFT 0
#define SDHCI_CDNS_HRS06 0x18 /* eMMC control */
#define SDHCI_CDNS_HRS06_TUNE_UP BIT(15)
#define SDHCI_CDNS_HRS06_TUNE_SHIFT 8
#define SDHCI_CDNS_HRS06_TUNE_MASK 0x3f
#define SDHCI_CDNS_HRS06_MODE_MASK 0x7
#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
/* 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
/*
* 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_priv {
void __iomem *hrs_addr;
};
static void 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;
tmp = (data << SDHCI_CDNS_HRS04_WDATA_SHIFT) |
(addr << SDHCI_CDNS_HRS04_ADDR_SHIFT);
writel(tmp, reg);
tmp |= SDHCI_CDNS_HRS04_WR;
writel(tmp, reg);
tmp &= ~SDHCI_CDNS_HRS04_WR;
writel(tmp, reg);
}
static void sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
{
sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_SD_HS, 4);
sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_SD_DEFAULT, 4);
sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_LEGACY, 9);
sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_SDR, 2);
sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_DDR, 3);
}
static inline 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. Divide it by 1000 to return a value in kHz.
*/
return host->max_clk / 1000;
}
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, tmp;
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:
mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
break;
default:
mode = SDHCI_CDNS_HRS06_MODE_SD;
break;
}
/* The speed mode for eMMC is selected by HRS06 register */
tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
tmp &= ~SDHCI_CDNS_HRS06_MODE_MASK;
tmp |= mode;
writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
/* 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_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;
if (WARN_ON(val > SDHCI_CDNS_HRS06_TUNE_MASK))
return -EINVAL;
tmp = readl(reg);
tmp &= ~(SDHCI_CDNS_HRS06_TUNE_MASK << SDHCI_CDNS_HRS06_TUNE_SHIFT);
tmp |= val << SDHCI_CDNS_HRS06_TUNE_SHIFT;
tmp |= SDHCI_CDNS_HRS06_TUNE_UP;
writel(tmp, reg);
return readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS06_TUNE_UP),
0, 1);
}
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 int sdhci_cdns_probe(struct platform_device *pdev)
{
struct sdhci_host *host;
struct sdhci_pltfm_host *pltfm_host;
struct sdhci_cdns_priv *priv;
struct clk *clk;
int ret;
clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(clk))
return PTR_ERR(clk);
ret = clk_prepare_enable(clk);
if (ret)
return ret;
host = sdhci_pltfm_init(pdev, &sdhci_cdns_pltfm_data, sizeof(*priv));
if (IS_ERR(host)) {
ret = PTR_ERR(host);
goto disable_clk;
}
pltfm_host = sdhci_priv(host);
pltfm_host->clk = clk;
priv = sdhci_cdns_priv(host);
priv->hrs_addr = host->ioaddr;
host->ioaddr += SDHCI_CDNS_SRS_BASE;
host->mmc_host_ops.execute_tuning = sdhci_cdns_execute_tuning;
ret = mmc_of_parse(host->mmc);
if (ret)
goto free;
sdhci_cdns_phy_init(priv);
ret = sdhci_add_host(host);
if (ret)
goto free;
return 0;
free:
sdhci_pltfm_free(pdev);
disable_clk:
clk_disable_unprepare(clk);
return ret;
}
static const struct of_device_id sdhci_cdns_match[] = {
{ .compatible = "socionext,uniphier-sd4hc" },
{ .compatible = "cdns,sd4hc" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
static struct platform_driver sdhci_cdns_driver = {
.driver = {
.name = "sdhci-cdns",
.pm = &sdhci_pltfm_pmops,
.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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