[PATCH 13/32] omap_hsmmc: context save/restore support

Adrian Hunter
2009-07-10T12:41:22Z

>From 3eb49df725b26329e85db6e4fc6f72fc029501a3 Mon Sep 17 00:00:00 2001
From: Denis Karpov <ext-denis.2.karpov@nokia.com>
Date: Wed, 22 Apr 2009 16:04:25 +0200
Subject: [PATCH] omap_hsmmc: context save/restore support

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>
---
drivers/mmc/host/omap_hsmmc.c | 194 ++++++++++++++++++++++++++++++++++++++--
1 files changed, 184 insertions(+), 10 deletions(-)

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index dad0548..762aa01 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -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
@@ -94,6 +95,8 @@
#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
@@ -152,6 +155,8 @@ struct mmc_omap_host {
int slot_id;
int dbclk_enabled;
int response_busy;
+ int context_loss;
+
struct omap_mmc_platform_data *pdata;
};

@@ -166,6 +171,166 @@ 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
@@ -823,6 +988,7 @@ 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;
}

@@ -830,6 +996,7 @@ 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;
@@ -934,7 +1101,7 @@ 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);

@@ -1014,12 +1181,19 @@ 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");
@@ -1144,6 +1318,8 @@ 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, msecs_to_jiffies(100));
if (mmc_host_enable(host->mmc) != 0) {
@@ -1378,21 +1554,19 @@ 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) {
--
1.5.6.3