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omap_hsmmc: context save/restore support
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Keep the context over PM dynamic OFF states.

Signed-off-by: Denis Karpov <ext-denis.2.karpov@nokia.com>
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Matt Fleming <matt@console-pimps.org>
Cc: Ian Molton <ian@mnementh.co.uk>
Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Denis Karpov <ext-denis.2.karpov@nokia.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Philip Langdale <philipl@overt.org>
Cc: "Madhusudhan" <madhu.cr@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Denis Karpov authored and Linus Torvalds committed Sep 23, 2009
1 parent a362146 commit 11dd62a
Showing 1 changed file with 184 additions and 10 deletions.
194 changes: 184 additions & 10 deletions drivers/mmc/host/omap_hsmmc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -37,6 +37,7 @@

/* OMAP HSMMC Host Controller Registers */
#define OMAP_HSMMC_SYSCONFIG 0x0010
#define OMAP_HSMMC_SYSSTATUS 0x0014
#define OMAP_HSMMC_CON 0x002C
#define OMAP_HSMMC_BLK 0x0104
#define OMAP_HSMMC_ARG 0x0108
Expand Down Expand Up @@ -96,6 +97,8 @@
#define DUAL_VOLT_OCR_BIT 7
#define SRC (1 << 25)
#define SRD (1 << 26)
#define SOFTRESET (1 << 1)
#define RESETDONE (1 << 0)

/*
* FIXME: Most likely all the data using these _DEVID defines should come
Expand Down Expand Up @@ -154,6 +157,8 @@ struct mmc_omap_host {
int slot_id;
int dbclk_enabled;
int response_busy;
int context_loss;

struct omap_mmc_platform_data *pdata;
};

Expand All @@ -168,6 +173,166 @@ static void omap_mmc_stop_clock(struct mmc_omap_host *host)
dev_dbg(mmc_dev(host->mmc), "MMC Clock is not stoped\n");
}

#ifdef CONFIG_PM

/*
* Restore the MMC host context, if it was lost as result of a
* power state change.
*/
static int omap_mmc_restore_ctx(struct mmc_omap_host *host)
{
struct mmc_ios *ios = &host->mmc->ios;
struct omap_mmc_platform_data *pdata = host->pdata;
int context_loss = 0;
u32 hctl, capa, con;
u16 dsor = 0;
unsigned long timeout;

if (pdata->get_context_loss_count) {
context_loss = pdata->get_context_loss_count(host->dev);
if (context_loss < 0)
return 1;
}

dev_dbg(mmc_dev(host->mmc), "context was %slost\n",
context_loss == host->context_loss ? "not " : "");
if (host->context_loss == context_loss)
return 1;

/* Wait for hardware reset */
timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
while ((OMAP_HSMMC_READ(host->base, SYSSTATUS) & RESETDONE) != RESETDONE
&& time_before(jiffies, timeout))
;

/* Do software reset */
OMAP_HSMMC_WRITE(host->base, SYSCONFIG, SOFTRESET);
timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
while ((OMAP_HSMMC_READ(host->base, SYSSTATUS) & RESETDONE) != RESETDONE
&& time_before(jiffies, timeout))
;

OMAP_HSMMC_WRITE(host->base, SYSCONFIG,
OMAP_HSMMC_READ(host->base, SYSCONFIG) | AUTOIDLE);

if (host->id == OMAP_MMC1_DEVID) {
if (host->power_mode != MMC_POWER_OFF &&
(1 << ios->vdd) <= MMC_VDD_23_24)
hctl = SDVS18;
else
hctl = SDVS30;
capa = VS30 | VS18;
} else {
hctl = SDVS18;
capa = VS18;
}

OMAP_HSMMC_WRITE(host->base, HCTL,
OMAP_HSMMC_READ(host->base, HCTL) | hctl);

OMAP_HSMMC_WRITE(host->base, CAPA,
OMAP_HSMMC_READ(host->base, CAPA) | capa);

OMAP_HSMMC_WRITE(host->base, HCTL,
OMAP_HSMMC_READ(host->base, HCTL) | SDBP);

timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
while ((OMAP_HSMMC_READ(host->base, HCTL) & SDBP) != SDBP
&& time_before(jiffies, timeout))
;

OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
OMAP_HSMMC_WRITE(host->base, ISE, INT_EN_MASK);
OMAP_HSMMC_WRITE(host->base, IE, INT_EN_MASK);

/* Do not initialize card-specific things if the power is off */
if (host->power_mode == MMC_POWER_OFF)
goto out;

con = OMAP_HSMMC_READ(host->base, CON);
switch (ios->bus_width) {
case MMC_BUS_WIDTH_8:
OMAP_HSMMC_WRITE(host->base, CON, con | DW8);
break;
case MMC_BUS_WIDTH_4:
OMAP_HSMMC_WRITE(host->base, CON, con & ~DW8);
OMAP_HSMMC_WRITE(host->base, HCTL,
OMAP_HSMMC_READ(host->base, HCTL) | FOUR_BIT);
break;
case MMC_BUS_WIDTH_1:
OMAP_HSMMC_WRITE(host->base, CON, con & ~DW8);
OMAP_HSMMC_WRITE(host->base, HCTL,
OMAP_HSMMC_READ(host->base, HCTL) & ~FOUR_BIT);
break;
}

if (ios->clock) {
dsor = OMAP_MMC_MASTER_CLOCK / ios->clock;
if (dsor < 1)
dsor = 1;

if (OMAP_MMC_MASTER_CLOCK / dsor > ios->clock)
dsor++;

if (dsor > 250)
dsor = 250;
}

OMAP_HSMMC_WRITE(host->base, SYSCTL,
OMAP_HSMMC_READ(host->base, SYSCTL) & ~CEN);
OMAP_HSMMC_WRITE(host->base, SYSCTL, (dsor << 6) | (DTO << 16));
OMAP_HSMMC_WRITE(host->base, SYSCTL,
OMAP_HSMMC_READ(host->base, SYSCTL) | ICE);

timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
while ((OMAP_HSMMC_READ(host->base, SYSCTL) & ICS) != ICS
&& time_before(jiffies, timeout))
;

OMAP_HSMMC_WRITE(host->base, SYSCTL,
OMAP_HSMMC_READ(host->base, SYSCTL) | CEN);

con = OMAP_HSMMC_READ(host->base, CON);
if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
OMAP_HSMMC_WRITE(host->base, CON, con | OD);
else
OMAP_HSMMC_WRITE(host->base, CON, con & ~OD);
out:
host->context_loss = context_loss;

dev_dbg(mmc_dev(host->mmc), "context is restored\n");
return 0;
}

/*
* Save the MMC host context (store the number of power state changes so far).
*/
static void omap_mmc_save_ctx(struct mmc_omap_host *host)
{
struct omap_mmc_platform_data *pdata = host->pdata;
int context_loss;

if (pdata->get_context_loss_count) {
context_loss = pdata->get_context_loss_count(host->dev);
if (context_loss < 0)
return;
host->context_loss = context_loss;
}
}

#else

static int omap_mmc_restore_ctx(struct mmc_omap_host *host)
{
return 0;
}

static void omap_mmc_save_ctx(struct mmc_omap_host *host)
{
}

#endif

/*
* Send init stream sequence to card
* before sending IDLE command
Expand Down Expand Up @@ -830,13 +995,15 @@ static int omap_mmc_enable(struct mmc_host *mmc)
if (err)
return err;
dev_dbg(mmc_dev(host->mmc), "mmc_fclk: enabled\n");
omap_mmc_restore_ctx(host);
return 0;
}

static int omap_mmc_disable(struct mmc_host *mmc, int lazy)
{
struct mmc_omap_host *host = mmc_priv(mmc);

omap_mmc_save_ctx(host);
clk_disable(host->fclk);
dev_dbg(mmc_dev(host->mmc), "mmc_fclk: disabled\n");
return 0;
Expand Down Expand Up @@ -941,7 +1108,7 @@ static void omap_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)

/* Wait till the ICS bit is set */
timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
while ((OMAP_HSMMC_READ(host->base, SYSCTL) & ICS) != 0x2
while ((OMAP_HSMMC_READ(host->base, SYSCTL) & ICS) != ICS
&& time_before(jiffies, timeout))
msleep(1);

Expand Down Expand Up @@ -1021,12 +1188,19 @@ static int mmc_regs_show(struct seq_file *s, void *data)
{
struct mmc_host *mmc = s->private;
struct mmc_omap_host *host = mmc_priv(mmc);
struct omap_mmc_platform_data *pdata = host->pdata;
int context_loss = 0;

if (pdata->get_context_loss_count)
context_loss = pdata->get_context_loss_count(host->dev);

seq_printf(s, "mmc%d:\n"
" enabled:\t%d\n"
" nesting_cnt:\t%d\n"
" ctx_loss:\t%d:%d\n"
"\nregs:\n",
mmc->index, mmc->enabled ? 1 : 0, mmc->nesting_cnt);
mmc->index, mmc->enabled ? 1 : 0, mmc->nesting_cnt,
host->context_loss, context_loss);

if (clk_enable(host->fclk) != 0) {
seq_printf(s, "can't read the regs\n");
Expand Down Expand Up @@ -1151,6 +1325,8 @@ static int __init omap_mmc_probe(struct platform_device *pdev)
goto err1;
}

omap_mmc_save_ctx(host);

mmc->caps |= MMC_CAP_DISABLE;
mmc_set_disable_delay(mmc, 100);
if (mmc_host_enable(host->mmc) != 0) {
Expand Down Expand Up @@ -1385,21 +1561,19 @@ static int omap_mmc_resume(struct platform_device *pdev)
return 0;

if (host) {

if (mmc_host_enable(host->mmc) != 0)
goto clk_en_err;

ret = clk_enable(host->iclk);
if (ret) {
mmc_host_disable(host->mmc);
clk_put(host->fclk);
if (ret)
goto clk_en_err;
}

if (clk_enable(host->dbclk) != 0)
dev_dbg(mmc_dev(host->mmc),
"Enabling debounce clk failed\n");

if (mmc_host_enable(host->mmc) != 0) {
clk_disable(host->iclk);
goto clk_en_err;
}

omap_hsmmc_init(host);

if (host->pdata->resume) {
Expand Down

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