[PATCH 2/4] extcon: sm5502: Detect cable state after completing platform booting

From: Chanwoo Choi
Date: Wed May 28 2014 - 05:39:58 EST


This patch detect whether cable is connected or not and the cable type
after completing kernel/platform booting using system_power_efficient_wq.

Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
---
drivers/extcon/extcon-sm5502.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)

diff --git a/drivers/extcon/extcon-sm5502.c b/drivers/extcon/extcon-sm5502.c
index ebf3d5c..3588df0 100644
--- a/drivers/extcon/extcon-sm5502.c
+++ b/drivers/extcon/extcon-sm5502.c
@@ -28,6 +28,8 @@
#include <linux/extcon.h>
#include <linux/extcon/sm5502.h>

+#define DELAY_MS_DEFAULT 17000 /* unit: millisecond */
+
struct muic_irq {
unsigned int irq;
const char *name;
@@ -59,6 +61,14 @@ struct sm5502_muic_info {
unsigned int num_reg_data;

struct mutex mutex;
+
+ /*
+ * Use delayed workqueue to detect cable state and then
+ * notify cable state to notifiee/platform through uevent.
+ * After completing the booting of platform, the extcon provider
+ * driver should notify cable state to upper layer.
+ */
+ struct delayed_work wq_detcable;
};

/* Default value of SM5502 register to bring up MUIC device. */
@@ -341,6 +351,8 @@ static int sm5502_muic_cable_handler(struct sm5502_muic_info *info,
case SM5502_MUIC_ADC_OPEN_USB_OTG:
idx = EXTCON_CABLE_USB_HOST;
break;
+ case SM5502_MUIC_ADC_GROUND:
+ break;
default:
dev_dbg(info->dev,
"cannot handle this cable_type (0x%x)\n", cable_type);
@@ -433,6 +445,18 @@ static irqreturn_t sm5502_muic_irq_handler(int irq, void *data)
return IRQ_HANDLED;
}

+static void sm5502_muic_detect_cable_wq(struct work_struct *work)
+{
+ struct sm5502_muic_info *info = container_of(to_delayed_work(work),
+ struct sm5502_muic_info, wq_detcable);
+ int ret;
+
+ /* Notify the state of connector cable or not */
+ ret = sm5502_muic_cable_handler(info, true);
+ if (ret < 0)
+ dev_warn(info->dev, "failed to detect cable state\n");
+}
+
static void sm5502_init_dev_type(struct sm5502_muic_info *info)
{
unsigned int reg_data, vendor_id, version_id;
@@ -548,6 +572,18 @@ static int sm5022_muic_i2c_probe(struct i2c_client *i2c,
return ret;
}

+ /*
+ * Detect accessory after completing the initialization of platform
+ *
+ * - Use delayed workqueue to detect cable state and then
+ * notify cable state to notifiee/platform through uevent.
+ * After completing the booting of platform, the extcon provider
+ * driver should notify cable state to upper layer.
+ */
+ INIT_DELAYED_WORK(&info->wq_detcable, sm5502_muic_detect_cable_wq);
+ queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
+ msecs_to_jiffies(DELAY_MS_DEFAULT));
+
/* Initialize SM5502 device and print vendor id and version id */
sm5502_init_dev_type(info);

--
1.8.0

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