diff mbox

[1/3] mmc: dw_mmc: use slot-gpio to handle cd pin

Message ID 1389278112-7099-2-git-send-email-zhangfei.gao@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Zhangfei Gao Jan. 9, 2014, 2:35 p.m. UTC
Suggested by Jaehoon: Use slot-gpio to handle cd-gpio
Add function dw_mci_of_get_cd_gpio to check "cd-gpios" from dts.
mmc_gpio_request_cd and mmc_gpio_get_cd are used to handle cd pin

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
---
 drivers/mmc/host/dw_mmc.c |   48 +++++++++++++++++++++++++++++++++------------
 1 file changed, 35 insertions(+), 13 deletions(-)

Comments

Arnd Bergmann Jan. 9, 2014, 2:38 p.m. UTC | #1
On Thursday 09 January 2014, Zhangfei Gao wrote:
> Suggested by Jaehoon: Use slot-gpio to handle cd-gpio
> Add function dw_mci_of_get_cd_gpio to check "cd-gpios" from dts.
> mmc_gpio_request_cd and mmc_gpio_get_cd are used to handle cd pin
> 
> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
> Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
> ---
>  drivers/mmc/host/dw_mmc.c |   48 +++++++++++++++++++++++++++++++++------------
>  1 file changed, 35 insertions(+), 13 deletions(-)

Acked-by: Arnd Bergmann <arnd@arndb.de>
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Kevin Hilman Jan. 14, 2014, 3:58 p.m. UTC | #2
On Thu, Jan 9, 2014 at 6:35 AM, Zhangfei Gao <zhangfei.gao@linaro.org> wrote:
> Suggested by Jaehoon: Use slot-gpio to handle cd-gpio
> Add function dw_mci_of_get_cd_gpio to check "cd-gpios" from dts.
> mmc_gpio_request_cd and mmc_gpio_get_cd are used to handle cd pin
>
> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
> Acked-by: Jaehoon Chung <jh80.chung@samsung.com>

The Samsung Arndale board started failing boot from MMC root tests
starting with next-20140113 and I bisected it down to this patch.
Reverting this patch on top of next-20140114 gets Arndale booting
again from MMC.  Is there some supporting DT data that's missing for
Arndale?

Kevin
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Olof Johansson Jan. 14, 2014, 5:23 p.m. UTC | #3
On Tue, Jan 14, 2014 at 7:58 AM, Kevin Hilman <khilman@linaro.org> wrote:
> On Thu, Jan 9, 2014 at 6:35 AM, Zhangfei Gao <zhangfei.gao@linaro.org> wrote:
>> Suggested by Jaehoon: Use slot-gpio to handle cd-gpio
>> Add function dw_mci_of_get_cd_gpio to check "cd-gpios" from dts.
>> mmc_gpio_request_cd and mmc_gpio_get_cd are used to handle cd pin
>>
>> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
>> Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
>
> The Samsung Arndale board started failing boot from MMC root tests
> starting with next-20140113 and I bisected it down to this patch.
> Reverting this patch on top of next-20140114 gets Arndale booting
> again from MMC.  Is there some supporting DT data that's missing for
> Arndale?

Rather, it looks like this patch changes behaviour and no longer uses
dw_mci_get_cd() to find out if there's a card attached -- it switches
to rely only on GPIO (see the last chunk in the patch). That seems
broken?


-Olof
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Zhangfei Gao Jan. 15, 2014, 1:09 a.m. UTC | #4
On 01/15/2014 01:23 AM, Olof Johansson wrote:
> On Tue, Jan 14, 2014 at 7:58 AM, Kevin Hilman <khilman@linaro.org> wrote:
>> On Thu, Jan 9, 2014 at 6:35 AM, Zhangfei Gao <zhangfei.gao@linaro.org> wrote:
>>> Suggested by Jaehoon: Use slot-gpio to handle cd-gpio
>>> Add function dw_mci_of_get_cd_gpio to check "cd-gpios" from dts.
>>> mmc_gpio_request_cd and mmc_gpio_get_cd are used to handle cd pin
>>>
>>> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
>>> Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
>>
>> The Samsung Arndale board started failing boot from MMC root tests
>> starting with next-20140113 and I bisected it down to this patch.
>> Reverting this patch on top of next-20140114 gets Arndale booting
>> again from MMC.  Is there some supporting DT data that's missing for
>> Arndale?
>
> Rather, it looks like this patch changes behaviour and no longer uses
> dw_mci_get_cd() to find out if there's a card attached -- it switches
> to rely only on GPIO (see the last chunk in the patch). That seems
> broken?
>
Oops,
Change using dw_mci_get_cd set flag DW_MMC_CARD_PRESENT.
And dw_mci_get_cd is called from mmc_rescan, a litter later than 
dw_mci_probe.
Is that too late?

Thanks
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diff mbox

Patch

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 4bce0deec362..a776f24f4311 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -36,6 +36,7 @@ 
 #include <linux/workqueue.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
+#include <linux/mmc/slot-gpio.h>
 
 #include "dw_mmc.h"
 
@@ -1032,20 +1033,26 @@  static int dw_mci_get_cd(struct mmc_host *mmc)
 	int present;
 	struct dw_mci_slot *slot = mmc_priv(mmc);
 	struct dw_mci_board *brd = slot->host->pdata;
+	int gpio_cd = !mmc_gpio_get_cd(mmc);
 
 	/* Use platform get_cd function, else try onboard card detect */
 	if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
 		present = 1;
 	else if (brd->get_cd)
 		present = !brd->get_cd(slot->id);
+	else if (!IS_ERR_VALUE(gpio_cd))
+		present = !!gpio_cd;
 	else
 		present = (mci_readl(slot->host, CDETECT) & (1 << slot->id))
 			== 0 ? 1 : 0;
 
-	if (present)
+	if (present) {
+		set_bit(DW_MMC_CARD_PRESENT, &slot->flags);
 		dev_dbg(&mmc->class_dev, "card is present\n");
-	else
+	} else {
+		clear_bit(DW_MMC_CARD_PRESENT, &slot->flags);
 		dev_dbg(&mmc->class_dev, "card is not present\n");
+	}
 
 	return present;
 }
@@ -1926,10 +1933,6 @@  static void dw_mci_work_routine_card(struct work_struct *work)
 			/* Card change detected */
 			slot->last_detect_state = present;
 
-			/* Mark card as present if applicable */
-			if (present != 0)
-				set_bit(DW_MMC_CARD_PRESENT, &slot->flags);
-
 			/* Clean up queue if present */
 			mrq = slot->mrq;
 			if (mrq) {
@@ -1977,8 +1980,6 @@  static void dw_mci_work_routine_card(struct work_struct *work)
 
 			/* Power down slot */
 			if (present == 0) {
-				clear_bit(DW_MMC_CARD_PRESENT, &slot->flags);
-
 				/* Clear down the FIFO */
 				dw_mci_fifo_reset(host);
 #ifdef CONFIG_MMC_DW_IDMAC
@@ -2079,6 +2080,26 @@  static int dw_mci_of_get_wp_gpio(struct device *dev, u8 slot)
 
 	return gpio;
 }
+
+/* find the cd gpio for a given slot; or -1 if none specified */
+static void dw_mci_of_get_cd_gpio(struct device *dev, u8 slot,
+					struct mmc_host *mmc)
+{
+	struct device_node *np = dw_mci_of_find_slot_node(dev, slot);
+	int gpio;
+
+	if (!np)
+		return;
+
+	gpio = of_get_named_gpio(np, "cd-gpios", 0);
+
+	/* Having a missing entry is valid; return silently */
+	if (!gpio_is_valid(gpio))
+		return;
+
+	if (mmc_gpio_request_cd(mmc, gpio, 0))
+		dev_warn(dev, "gpio [%d] request failed\n", gpio);
+}
 #else /* CONFIG_OF */
 static int dw_mci_of_get_slot_quirks(struct device *dev, u8 slot)
 {
@@ -2096,6 +2117,11 @@  static int dw_mci_of_get_wp_gpio(struct device *dev, u8 slot)
 {
 	return -EINVAL;
 }
+static void dw_mci_of_get_cd_gpio(struct device *dev, u8 slot,
+					struct mmc_host *mmc)
+{
+	return;
+}
 #endif /* CONFIG_OF */
 
 static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
@@ -2197,12 +2223,8 @@  static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
 #endif /* CONFIG_MMC_DW_IDMAC */
 	}
 
-	if (dw_mci_get_cd(mmc))
-		set_bit(DW_MMC_CARD_PRESENT, &slot->flags);
-	else
-		clear_bit(DW_MMC_CARD_PRESENT, &slot->flags);
-
 	slot->wp_gpio = dw_mci_of_get_wp_gpio(host->dev, slot->id);
+	dw_mci_of_get_cd_gpio(host->dev, slot->id, mmc);
 
 	ret = mmc_add_host(mmc);
 	if (ret)