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mmc: sdhci-pci-o2micro: Fix O2 Host data read/write DLL Lock phase sh…
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…ift issue

Fix data read/write error in HS200 mode due to chip DLL lock phase shift

Signed-off-by: Shirley Her <shirley.her@bayhubtech.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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Shirley Her (SC) authored and Ulf Hansson committed Sep 11, 2019
1 parent 908fd50 commit 7d44061
Showing 1 changed file with 122 additions and 2 deletions.
124 changes: 122 additions & 2 deletions drivers/mmc/host/sdhci-pci-o2micro.c
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/delay.h>
#include <linux/iopoll.h>

#include "sdhci.h"
#include "sdhci-pci.h"
Expand Down Expand Up @@ -55,9 +56,18 @@
#define O2_PLL_FORCE_ACTIVE BIT(18)
#define O2_PLL_LOCK_STATUS BIT(14)
#define O2_PLL_SOFT_RESET BIT(12)
#define O2_DLL_LOCK_STATUS BIT(11)

#define O2_SD_DETECT_SETTING 0x324

static const u32 dmdn_table[] = {0x2B1C0000,
0x2C1A0000, 0x371B0000, 0x35100000};
#define DMDN_SZ ARRAY_SIZE(dmdn_table)

struct o2_host {
u8 dll_adjust_count;
};

static void sdhci_o2_wait_card_detect_stable(struct sdhci_host *host)
{
ktime_t timeout;
Expand Down Expand Up @@ -133,7 +143,8 @@ static int sdhci_o2_get_cd(struct mmc_host *mmc)
{
struct sdhci_host *host = mmc_priv(mmc);

sdhci_o2_enable_internal_clock(host);
if (!(sdhci_readw(host, O2_PLL_DLL_WDT_CONTROL1) & O2_PLL_LOCK_STATUS))
sdhci_o2_enable_internal_clock(host);

return !!(sdhci_readl(host, SDHCI_PRESENT_STATE) & SDHCI_CARD_PRESENT);
}
Expand All @@ -152,6 +163,25 @@ static void o2_pci_set_baseclk(struct sdhci_pci_chip *chip, u32 value)
O2_SD_PLL_SETTING, scratch_32);
}

static u32 sdhci_o2_pll_dll_wdt_control(struct sdhci_host *host)
{
return sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
}

/*
* This function is used to detect dll lock status.
* Since the dll lock status bit will toggle randomly
* with very short interval which needs to be polled
* as fast as possible. Set sleep_us as 1 microsecond.
*/
static int sdhci_o2_wait_dll_detect_lock(struct sdhci_host *host)
{
u32 scratch32 = 0;

return readx_poll_timeout(sdhci_o2_pll_dll_wdt_control, host,
scratch32, !(scratch32 & O2_DLL_LOCK_STATUS), 1, 1000000);
}

static void sdhci_o2_set_tuning_mode(struct sdhci_host *host)
{
u16 reg;
Expand Down Expand Up @@ -189,6 +219,83 @@ static void __sdhci_o2_execute_tuning(struct sdhci_host *host, u32 opcode)
sdhci_reset_tuning(host);
}

/*
* This function is used to fix o2 dll shift issue.
* It isn't necessary to detect card present before recovery.
* Firstly, it is used by bht emmc card, which is embedded.
* Second, before call recovery card present will be detected
* outside of the execute tuning function.
*/
static int sdhci_o2_dll_recovery(struct sdhci_host *host)
{
int ret = 0;
u8 scratch_8 = 0;
u32 scratch_32 = 0;
struct sdhci_pci_slot *slot = sdhci_priv(host);
struct sdhci_pci_chip *chip = slot->chip;
struct o2_host *o2_host = sdhci_pci_priv(slot);

/* UnLock WP */
pci_read_config_byte(chip->pdev,
O2_SD_LOCK_WP, &scratch_8);
scratch_8 &= 0x7f;
pci_write_config_byte(chip->pdev, O2_SD_LOCK_WP, scratch_8);
while (o2_host->dll_adjust_count < DMDN_SZ && !ret) {
/* Disable clock */
sdhci_writeb(host, 0, SDHCI_CLOCK_CONTROL);

/* PLL software reset */
scratch_32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
scratch_32 |= O2_PLL_SOFT_RESET;
sdhci_writel(host, scratch_32, O2_PLL_DLL_WDT_CONTROL1);

pci_read_config_dword(chip->pdev,
O2_SD_FUNC_REG4,
&scratch_32);
/* Enable Base Clk setting change */
scratch_32 |= O2_SD_FREG4_ENABLE_CLK_SET;
pci_write_config_dword(chip->pdev, O2_SD_FUNC_REG4, scratch_32);
o2_pci_set_baseclk(chip, dmdn_table[o2_host->dll_adjust_count]);

/* Enable internal clock */
scratch_8 = SDHCI_CLOCK_INT_EN;
sdhci_writeb(host, scratch_8, SDHCI_CLOCK_CONTROL);

if (sdhci_o2_get_cd(host->mmc)) {
/*
* need wait at least 5ms for dll status stable,
* after enable internal clock
*/
usleep_range(5000, 6000);
if (sdhci_o2_wait_dll_detect_lock(host)) {
scratch_8 |= SDHCI_CLOCK_CARD_EN;
sdhci_writeb(host, scratch_8,
SDHCI_CLOCK_CONTROL);
ret = 1;
} else {
pr_warn("%s: DLL unlocked when dll_adjust_count is %d.\n",
mmc_hostname(host->mmc),
o2_host->dll_adjust_count);
}
} else {
pr_err("%s: card present detect failed.\n",
mmc_hostname(host->mmc));
break;
}

o2_host->dll_adjust_count++;
}
if (!ret && o2_host->dll_adjust_count == DMDN_SZ)
pr_err("%s: DLL adjust over max times\n",
mmc_hostname(host->mmc));
/* Lock WP */
pci_read_config_byte(chip->pdev,
O2_SD_LOCK_WP, &scratch_8);
scratch_8 |= 0x80;
pci_write_config_byte(chip->pdev, O2_SD_LOCK_WP, scratch_8);
return ret;
}

static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode)
{
struct sdhci_host *host = mmc_priv(mmc);
Expand All @@ -203,7 +310,16 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode)

if (WARN_ON(opcode != MMC_SEND_TUNING_BLOCK_HS200))
return -EINVAL;

/*
* Judge the tuning reason, whether caused by dll shift
* If cause by dll shift, should call sdhci_o2_dll_recovery
*/
if (!sdhci_o2_wait_dll_detect_lock(host))
if (!sdhci_o2_dll_recovery(host)) {
pr_err("%s: o2 dll recovery failed\n",
mmc_hostname(host->mmc));
return -EINVAL;
}
/*
* o2 sdhci host didn't support 8bit emmc tuning
*/
Expand Down Expand Up @@ -371,6 +487,7 @@ static void sdhci_o2_enable_clk(struct sdhci_host *host, u16 clk)
clk |= SDHCI_CLOCK_INT_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);

sdhci_o2_enable_internal_clock(host);
if (sdhci_o2_get_cd(host->mmc)) {
clk |= SDHCI_CLOCK_CARD_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
Expand All @@ -396,12 +513,14 @@ int sdhci_pci_o2_probe_slot(struct sdhci_pci_slot *slot)
{
struct sdhci_pci_chip *chip;
struct sdhci_host *host;
struct o2_host *o2_host = sdhci_pci_priv(slot);
u32 reg, caps;
int ret;

chip = slot->chip;
host = slot->host;

o2_host->dll_adjust_count = 0;
caps = sdhci_readl(host, SDHCI_CAPABILITIES);

/*
Expand Down Expand Up @@ -688,4 +807,5 @@ const struct sdhci_pci_fixes sdhci_o2 = {
.resume = sdhci_pci_o2_resume,
#endif
.ops = &sdhci_pci_o2_ops,
.priv_size = sizeof(struct o2_host),
};

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