[PATCH v2] SDHCI-S3C updates

[PATCH v2] SDHCI-S3C updates

[Marek Szyprowski]

Hello,

This is an updated version of the patches I've sent yesterday. I've
fixed issues reported by Maurus Cuelenaere and Ben Dooks.

This patch series includes various updates to sdhci-s3c driver. The
patches has been rebased onto latest -mm kernel tree from
git://zen-kernel.org/kernel/mmotm.git (2010-07-27-14-56 snapshot).

All required platform changes has been already merged by Kukjin Kim and
are available in linux-next kernel tree - see commit:
848a3aeee01c8c805f8dad4ae2963473975410d1 from
git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung.git
for-next branch.

A complete list of patches:

[PATCHv3 1/4] sdhci-s3c: add support for the non standard minimal clock value
[PATCH 2/4] sdhci-s3c: enable SDHCI_QUIRK_NO_HISPD_BIT quirk
[PATCHv6 3/4] sdhci-s3c: add support for new card detection methods
[PATCHv2 4/4] sdhci: add regulator support

Best regards
-- 
Marek Szyprowski
Samsung Poland R&D Center

[PATCHv3 1/4] sdhci-s3c: add support for the non standard minimal clock value

[Marek Szyprowski]

S3C SDHCI host controller can change the source for generating mmc
clock. By default host bus clock is used, what causes some problems on
machines with 133MHz bus, because the SDHCI divider cannot be as high
get proper clock value for identification mode. This is not a problem
for the controller, because it can generate lower frequencies from other
clock sources. This patch changes sdhci driver to use get_min_clock()
call if it has been provided.

This fixes the flood of the following warnings on Samsung S5PV210 SoCs:
mmc0: Minimum clock frequency too high for identification mode

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---

Changes since V2: 
- removed the need for additional quirk, just use get_min_clock() method
if provided

Changes since V1:
- rebased onto latest -mm kernel tree
---
 drivers/mmc/host/sdhci-s3c.c |   27 +++++++++++++++++++++++++++
 drivers/mmc/host/sdhci.c     |    3 +--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index d7058ee..47138af 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -203,9 +203,36 @@ static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
 	}
 }
 
+/**
+ * sdhci_s3c_get_min_clock - callback to get minimal supported clock value
+ * @host: The SDHCI host being queried
+ *
+ * To init mmc host properly a minimal clock value is needed. For high system
+ * bus clock's values the standard formula gives values out of allowed range.
+ * The clock still can be set to lower values, if clock source other then
+ * system bus is selected.
+*/
+static unsigned int sdhci_s3c_get_min_clock(struct sdhci_host *host)
+{
+	struct sdhci_s3c *ourhost = to_s3c(host);
+	unsigned int delta, min = UINT_MAX;
+	int src;
+
+	for (src = 0; src < MAX_BUS_CLK; src++) {
+		delta = sdhci_s3c_consider_clock(ourhost, src, 0);
+		if (delta == UINT_MAX)
+			continue;
+		/* delta is a negative value in this case */
+		if (-delta < min)
+			min = -delta;
+	}
+	return min;
+}
+
 static struct sdhci_ops sdhci_s3c_ops = {
 	.get_max_clock		= sdhci_s3c_get_max_clk,
 	.set_clock		= sdhci_s3c_set_clock,
+	.get_min_clock		= sdhci_s3c_get_min_clock,
 };
 
 static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 07b2695..1c67f91 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1776,8 +1776,7 @@ int sdhci_add_host(struct sdhci_host *host)
 	 * Set host parameters.
 	 */
 	mmc->ops = &sdhci_ops;
-	if (host->quirks & SDHCI_QUIRK_NONSTANDARD_CLOCK &&
-			host->ops->get_min_clock)
+	if (host->ops->get_min_clock)
 		mmc->f_min = host->ops->get_min_clock(host);
 	else
 		mmc->f_min = host->max_clk / 256;
-- 
1.7.1.569.g6f426

[PATCH 2/4] sdhci-s3c: enable SDHCI_QUIRK_NO_HISPD_BIT quirk

[Marek Szyprowski]

This patch enables SDHCI_QUIRK_NO_HISPD_BIT on Samsung SDHCI driver.
This solves detection problems with some external SD cards. This change
has been tested on S5PC100 and S5PC110. It has no inpact on driver
speed.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/mmc/host/sdhci-s3c.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index 47138af..f0b819d 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -338,6 +338,7 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
 
 	/* Setup quirks for the controller */
 	host->quirks |= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC;
+	host->quirks |= SDHCI_QUIRK_NO_HISPD_BIT;
 
 #ifndef CONFIG_MMC_SDHCI_S3C_DMA
 
-- 
1.7.1.569.g6f426

[PATCHv6 3/4] sdhci-s3c: add support for new card detection methods

[Marek Szyprowski]

On some Samsung SoCs not all SDHCI controllers have card detect (CD)
line. For some embedded designs it is not even needed, because ususally
the device (like SDIO flash memory or wifi controller) is permanently
wired to the controller. There are also systems which have a card detect
line connected to some of the external interrupt lines or the presence
of the card depends on some other actions (like enabling a power
regulator).

This patch adds support for all these cases. The following card
detection methods are possible:

1. internal sdhci host card detect line
2. external event
3. external gpio interrupt
4. no card detect line, controller will poll for the card
5. no card detect line, card is permanently wired to the controller
(once detected host won't poll it any more)

By default, all existing code would use method #1, what is compatible
with the previous version of the driver.

In case of external event, two callbacks must be provided in platdata:
ext_cd_init and ext_cd_cleanup. Both of them get a callback to a
function that notifies the s3c-sdhci host contoller as their argument.
That callback function should be called from the even dispatcher to let
host notice the card insertion/removal.

In case of external gpio interrupt, a gpio pin number must be provided
in platdata (ext_cd_gpio parameter), as well as the information about
the polarity of that gpio pin (ext_cd_gpio_invert). By default
(ext_cd_gpio_invert == 0) gpio value 0 means 'card has been removed',
but this can be changed to 'card has been removed' when
ext_cd_gpio_invert == 1.

This patch adds all required changes to sdhci-s3c driver.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---

Changes since V5:
- resolved issues reported by Maurus Cuelenaere
- moved gpio card detection setup code to separate function

Changes since V4:
- adapted to threaded irq approach in sdhci driver
- rebased onto latest -mm kernel tree
- fixed problem when gpio-base card detection was not called on driver
init

Changes since V3:
- renamed patch to avoid confusion with the patch for the s3c-sdhci
platform changes - added "(driver part)" in subject

Changes since V2:
According to Andrew Morton's suggestion local_irq_save() call in the
sdhci_s3c_notify_change function has been replaced by spin_lock_irqsave
(host driver already has a spinlock that is used for protecting internal
state of the driver).

Changes since V1:
- added support for gpio external interrupt card based detect method
  directly to sdhci-s3c driver

---
 drivers/mmc/host/sdhci-s3c.c |   85 ++++++++++++++++++++++++++++++++++++++++++
 drivers/mmc/host/sdhci.c     |   47 +++++++++++++----------
 drivers/mmc/host/sdhci.h     |    1 +
 3 files changed, 113 insertions(+), 20 deletions(-)

diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index f0b819d..da70f73 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -18,6 +18,7 @@
 #include <linux/slab.h>
 #include <linux/clk.h>
 #include <linux/io.h>
+#include <linux/gpio.h>
 
 #include <linux/mmc/host.h>
 
@@ -44,6 +45,8 @@ struct sdhci_s3c {
 	struct resource		*ioarea;
 	struct s3c_sdhci_platdata *pdata;
 	unsigned int		cur_clk;
+	int			ext_cd_irq;
+	int			ext_cd_gpio;
 
 	struct clk		*clk_io;
 	struct clk		*clk_bus[MAX_BUS_CLK];
@@ -235,6 +238,61 @@ static struct sdhci_ops sdhci_s3c_ops = {
 	.get_min_clock		= sdhci_s3c_get_min_clock,
 };
 
+static void sdhci_s3c_notify_change(struct platform_device *dev, int state)
+{
+	struct sdhci_host *host = platform_get_drvdata(dev);
+	if (host) {
+		mutex_lock(&host->lock);
+		if (state) {
+			dev_dbg(&dev->dev, "card inserted.\n");
+			host->flags &= ~SDHCI_DEVICE_DEAD;
+			host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
+		} else {
+			dev_dbg(&dev->dev, "card removed.\n");
+			host->flags |= SDHCI_DEVICE_DEAD;
+			host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
+		}
+		sdhci_card_detect(host);
+		mutex_unlock(&host->lock);
+	}
+}
+
+static irqreturn_t sdhci_s3c_gpio_card_detect_thread(int irq, void *dev_id)
+{
+	struct sdhci_s3c *sc = dev_id;
+	int status = gpio_get_value(sc->ext_cd_gpio);
+	if (sc->pdata->ext_cd_gpio_invert)
+		status = !status;
+	sdhci_s3c_notify_change(sc->pdev, status);
+	return IRQ_HANDLED;
+}
+
+static void sdhci_s3c_setup_card_detect_gpio(struct sdhci_s3c *sc)
+{
+	struct s3c_sdhci_platdata *pdata = sc->pdata;
+	struct device *dev = &sc->pdev->dev;
+
+	if (gpio_request(pdata->ext_cd_gpio, "SDHCI EXT CD") == 0) {
+		sc->ext_cd_gpio = pdata->ext_cd_gpio;
+		sc->ext_cd_irq = gpio_to_irq(pdata->ext_cd_gpio);
+		if (sc->ext_cd_irq &&
+		    request_threaded_irq(sc->ext_cd_irq, NULL,
+					 sdhci_s3c_gpio_card_detect_thread,
+					 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+					 dev_name(dev), sc) == 0) {
+			int status = gpio_get_value(sc->ext_cd_gpio);
+			if (pdata->ext_cd_gpio_invert)
+				status = !status;
+			sdhci_s3c_notify_change(sc->pdev, status);
+		} else {
+			dev_warn(dev, "cannot request irq for card detect\n");
+			sc->ext_cd_irq = 0; 
+		}
+	} else {
+		dev_err(dev, "cannot request gpio for card detect\n");
+	}
+}
+
 static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
 {
 	struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
@@ -272,6 +330,7 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
 	sc->host = host;
 	sc->pdev = pdev;
 	sc->pdata = pdata;
+	sc->ext_cd_gpio = -1; /* invalid gpio number */
 
 	platform_set_drvdata(pdev, host);
 
@@ -353,6 +412,13 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
 	 * SDHCI block, or a missing configuration that needs to be set. */
 	host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ;
 
+	if (pdata->cd_type == S3C_SDHCI_CD_NONE ||
+	    pdata->cd_type == S3C_SDHCI_CD_PERMANENT)
+		host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
+
+	if (pdata->cd_type == S3C_SDHCI_CD_PERMANENT)
+		host->mmc->caps = MMC_CAP_NONREMOVABLE;
+
 	host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
 			 SDHCI_QUIRK_32BIT_DMA_SIZE);
 
@@ -365,6 +431,15 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
 		goto err_add_host;
 	}
 
+	/* The following two methods of card detection might call
+	   sdhci_s3c_notify_change() immediately, so they can be called
+	   only after sdhci_add_host(). Setup errors are ignored. */
+	if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_init)
+		pdata->ext_cd_init(&sdhci_s3c_notify_change);
+	if (pdata->cd_type == S3C_SDHCI_CD_GPIO &&
+	    gpio_is_valid(pdata->ext_cd_gpio))
+		sdhci_s3c_setup_card_detect_gpio(sc);
+
 	return 0;
 
  err_add_host:
@@ -389,10 +464,20 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
 
 static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
 {
+	struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
 	struct sdhci_host *host =  platform_get_drvdata(pdev);
 	struct sdhci_s3c *sc = sdhci_priv(host);
 	int ptr;
 
+	if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_cleanup)
+		pdata->ext_cd_cleanup(&sdhci_s3c_notify_change);
+
+	if (sc->ext_cd_irq)
+		free_irq(sc->ext_cd_irq, sc);
+
+	if (gpio_is_valid(sc->ext_cd_gpio))
+		gpio_free(sc->ext_cd_gpio);
+
 	sdhci_remove_host(host, 1);
 
 	for (ptr = 0; ptr < 3; ptr++) {
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 1c67f91..95f44ac 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1244,26 +1244,6 @@ static const struct mmc_host_ops sdhci_ops = {
  *                                                                           *
 \*****************************************************************************/
 
-static void sdhci_card_detect(struct sdhci_host *host)
-{
-	if (!(sdhci_readl(host, SDHCI_PRESENT_STATE) & SDHCI_CARD_PRESENT)) {
-		if (host->mrq) {
-			printk(KERN_ERR "%s: Card removed during transfer!\n",
-				mmc_hostname(host->mmc));
-			printk(KERN_ERR "%s: Resetting controller.\n",
-				mmc_hostname(host->mmc));
-
-			sdhci_reset(host, SDHCI_RESET_CMD);
-			sdhci_reset(host, SDHCI_RESET_DATA);
-
-			host->mrq->cmd->error = -ENOMEDIUM;
-			schedule_work(&host->finish_work);
-		}
-	}
-
-	mmc_detect_change(host->mmc, msecs_to_jiffies(200));
-}
-
 static void sdhci_finish_work(struct work_struct *wk)
 {
 	struct sdhci_host *host;
@@ -1627,6 +1607,33 @@ EXPORT_SYMBOL_GPL(sdhci_resume_host);
 
 /*****************************************************************************\
  *                                                                           *
+ * Implementation dependent callbacks                                        *
+ *                                                                           *
+\*****************************************************************************/
+
+void sdhci_card_detect(struct sdhci_host *host)
+{
+	if (!(sdhci_readl(host, SDHCI_PRESENT_STATE) & SDHCI_CARD_PRESENT)) {
+		if (host->mrq) {
+			printk(KERN_ERR "%s: Card removed during transfer!\n",
+				mmc_hostname(host->mmc));
+			printk(KERN_ERR "%s: Resetting controller.\n",
+				mmc_hostname(host->mmc));
+
+			sdhci_reset(host, SDHCI_RESET_CMD);
+			sdhci_reset(host, SDHCI_RESET_DATA);
+
+			host->mrq->cmd->error = -ENOMEDIUM;
+			schedule_work(&host->finish_work);
+		}
+	}
+
+	mmc_detect_change(host->mmc, msecs_to_jiffies(200));
+}
+EXPORT_SYMBOL_GPL(sdhci_card_detect);
+
+/*****************************************************************************\
+ *                                                                           *
  * Device allocation/registration                                            *
  *                                                                           *
 \*****************************************************************************/
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 2be34b3..253773e 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -415,6 +415,7 @@ static inline void *sdhci_priv(struct sdhci_host *host)
 	return (void *)host->private;
 }
 
+extern void sdhci_card_detect(struct sdhci_host *host);
 extern int sdhci_add_host(struct sdhci_host *host);
 extern void sdhci_remove_host(struct sdhci_host *host, int dead);
 
-- 
1.7.1.569.g6f426

[PATCHv2 4/4] sdhci: add regulator support

[Marek Szyprowski]

This patch adds support for regulator API to sdhci core driver. Regulators
can be used to disable power in suspended state to reduce dissipated
energy.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---

Changes since V1:
- moved regulator support from sdhci-s3c sub-driver to the main sdhci
driver

---
 drivers/mmc/host/sdhci.c |   26 +++++++++++++++++++++++++-
 drivers/mmc/host/sdhci.h |    2 ++
 2 files changed, 27 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 95f44ac..cdd974e 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -23,6 +23,7 @@
 #include <linux/mutex.h>
 #include <linux/scatterlist.h>
 #include <linux/jiffies.h>
+#include <linux/regulator/consumer.h>
 
 #include <linux/leds.h>
 
@@ -1573,7 +1574,10 @@ int sdhci_suspend_host(struct sdhci_host *host, pm_message_t state)
 
 	free_irq(host->irq, host);
 
-	return 0;
+	if (host->vmmc)
+		ret = regulator_disable(host->vmmc);
+
+	return ret;
 }
 
 EXPORT_SYMBOL_GPL(sdhci_suspend_host);
@@ -1582,6 +1586,13 @@ int sdhci_resume_host(struct sdhci_host *host)
 {
 	int ret;
 
+	if (host->vmmc) {
+		int ret = regulator_enable(host->vmmc);
+		if (ret)
+			return ret;
+	}
+
+
 	if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
 		if (host->ops->enable_dma)
 			host->ops->enable_dma(host);
@@ -1878,6 +1889,14 @@ int sdhci_add_host(struct sdhci_host *host)
 	if (ret)
 		return ret;
 
+	host->vmmc = regulator_get(mmc_dev(mmc), "vmmc");
+	if (IS_ERR(host->vmmc)) {
+		printk(KERN_INFO "%s: no vmmc regulator found\n", mmc_hostname(mmc));
+		host->vmmc = NULL;
+	} else {
+		regulator_enable(host->vmmc);
+	}
+
 	sdhci_init(host, 0);
 
 #ifdef CONFIG_MMC_DEBUG
@@ -1955,6 +1974,11 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
 
 	flush_work(&host->finish_work);
 
+	if (host->vmmc) {
+		regulator_disable(host->vmmc);
+		regulator_put(host->vmmc);
+	}
+
 	kfree(host->adma_desc);
 	kfree(host->align_buffer);
 
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 253773e..4d03e24 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -253,6 +253,8 @@ struct sdhci_host {
 
 	const struct sdhci_ops	*ops;		/* Low level hw interface */
 
+	struct regulator	*vmmc;		/* Power regulator */
+
 	/* Internal data */
 	struct mmc_host		*mmc;		/* MMC structure */
 	u64			dma_mask;	/* custom DMA mask */
-- 
1.7.1.569.g6f426

[PATCHv2 4/4] sdhci: add regulator support

[Mark Brown]

On Thu, Jul 29, 2010 at 02:34:35PM +0200, Marek Szyprowski wrote:
> This patch adds support for regulator API to sdhci core driver. Regulators
> can be used to disable power in suspended state to reduce dissipated
> energy.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

Looks good from a regulator point of view.

Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>