openwrt/target/linux/s3c24xx/patches-2.6.26/0176-fix-pcf50633-suspend-state-as-enum.patch.patch

From 591a5d7e8da059de812d315b865fd5c0fa89071e Mon Sep 17 00:00:00 2001
From: Andy Green <andy@openmoko.com>
Date: Fri, 25 Jul 2008 23:06:15 +0100
Subject: [PATCH] fix-pcf50633-suspend-state-as-enum.patch

Use an enum to define pcf50633 suspend / resume state.
Add PCF50633_SS_RESUMING_BUT_NOT_US_YET to be the state
early in resume: add platform driver resume function just
to set this state so we can differentiate between early
resume and late suspend.

Signed-off-by: Andy Green <andy@openmoko.com>
---
 drivers/i2c/chips/pcf50633.c |   73 ++++++++++++++++++++++++++++++++++--------
 1 files changed, 59 insertions(+), 14 deletions(-)

diff --git a/drivers/i2c/chips/pcf50633.c b/drivers/i2c/chips/pcf50633.c
index 37dfca6..87a3003 100644
--- a/drivers/i2c/chips/pcf50633.c
+++ b/drivers/i2c/chips/pcf50633.c
@@ -108,6 +108,16 @@ enum charger_type {
 
 #define MAX_ADC_FIFO_DEPTH 8
 
+enum pcf50633_suspend_states {
+	PCF50633_SS_RUNNING,
+	PCF50633_SS_STARTING_SUSPEND,
+	PCF50633_SS_COMPLETED_SUSPEND,
+	PCF50633_SS_RESUMING_BUT_NOT_US_YET,
+	PCF50633_SS_STARTING_RESUME,
+	PCF50633_SS_COMPLETED_RESUME,
+};
+
+
 struct pcf50633_data {
 	struct i2c_client client;
 	struct pcf50633_platform_data *pdata;
@@ -122,9 +132,9 @@ struct pcf50633_data {
 	int allow_close;
 	int onkey_seconds;
 	int irq;
-	int have_been_suspended;
+	enum pcf50633_suspend_states suspend_state;
 	int usb_removal_count;
-	unsigned char pcfirq_resume[5];
+	u8 pcfirq_resume[5];
 	int probe_completed;
 
 	/* if he pulls battery while charging, we notice that and correctly
@@ -191,7 +201,7 @@ static struct platform_device *pcf50633_pdev;
 
 static int __reg_write(struct pcf50633_data *pcf, u_int8_t reg, u_int8_t val)
 {
-	if (pcf->have_been_suspended == 1) {
+	if (pcf->suspend_state == PCF50633_SS_COMPLETED_SUSPEND) {
 		dev_err(&pcf->client.dev, "__reg_write while suspended\n");
 		dump_stack();
 	}
@@ -213,7 +223,7 @@ static int32_t __reg_read(struct pcf50633_data *pcf, u_int8_t reg)
 {
 	int32_t ret;
 
-	if (pcf->have_been_suspended == 1) {
+	if (pcf->suspend_state == PCF50633_SS_COMPLETED_SUSPEND) {
 		dev_err(&pcf->client.dev, "__reg_read while suspended\n");
 		dump_stack();
 	}
@@ -630,7 +640,8 @@ static void pcf50633_work_usbcurlim(struct work_struct *work)
 	/* we got a notification from USB stack before we completed resume...
 	 * that can only make trouble, reschedule for a retry
 	 */
-	if (pcf->have_been_suspended && (pcf->have_been_suspended < 3))
+	if (pcf->suspend_state &&
+		     (pcf->suspend_state < PCF50633_SS_COMPLETED_RESUME))
 		goto reschedule;
 
 	/*
@@ -751,6 +762,21 @@ static void pcf50633_work(struct work_struct *work)
 	pcf->working = 1;
 
 	/*
+	 * if we are presently suspending, we are not in a position to deal
+	 * with pcf50633 interrupts at all.
+	 *
+	 * Because we didn't clear the int pending registers, there will be
+	 * no edge / interrupt waiting for us when we wake.  But it is OK
+	 * because at the end of our resume, we call this workqueue function
+	 * gratuitously, clearing the pending register and re-enabling
+	 * servicing this interrupt.
+	 */
+
+	if ((pcf->suspend_state == PCF50633_SS_STARTING_SUSPEND) ||
+	    (pcf->suspend_state == PCF50633_SS_COMPLETED_SUSPEND))
+		goto bail;
+
+	/*
 	 * If we are inside suspend -> resume completion time we don't attempt
 	 * service until we have fully resumed.  Although we could talk to the
 	 * device as soon as I2C is up, the regs in the device which we might
@@ -1154,8 +1180,9 @@ reschedule:
 	/* EXCEPTION: if we are in the middle of suspending, we don't have
 	 * time to hang around since we may be turned off core 1V3 already
 	 */
-	if (pcf->have_been_suspended != 1) {
-		msleep(50);
+	if ((pcf->suspend_state != PCF50633_SS_STARTING_SUSPEND) &&
+	    (pcf->suspend_state != PCF50633_SS_COMPLETED_SUSPEND)) {
+		msleep(10);
 		dev_info(&pcf->client.dev, "rescheduling interrupt service\n");
 	}
 	if (!schedule_work(&pcf->work))
@@ -2315,8 +2342,9 @@ static int pcf50633_suspend(struct device *dev, pm_message_t state)
 
 	/* we suspend once (!) as late as possible in the suspend sequencing */
 
-	if ((state.event != PM_EVENT_SUSPEND) || (pcf->have_been_suspended))
-		return 0;
+	if ((state.event != PM_EVENT_SUSPEND) ||
+	    (pcf->suspend_state != PCF50633_SS_RUNNING))
+		return -EBUSY;
 
 	/* The general idea is to power down all unused power supplies,
 	 * and then mask all PCF50633 interrupt sources but EXTONR, ONKEYF
@@ -2380,7 +2408,7 @@ static int pcf50633_suspend(struct device *dev, pm_message_t state)
 	if (ret)
 		dev_err(dev, "Failed to set wake masks :-( %d\n", ret);
 
-	pcf->have_been_suspended = 1;
+	pcf->suspend_state = PCF50633_SS_COMPLETED_SUSPEND;
 
 	mutex_unlock(&pcf->lock);
 
@@ -2393,7 +2421,8 @@ int pcf50633_ready(struct pcf50633_data *pcf)
 	if (!pcf)
 		return -EACCES;
 
-	if (pcf->have_been_suspended && (pcf->have_been_suspended < 3))
+	if ((pcf->suspend_state != PCF50633_SS_RUNNING) &&
+	    (pcf->suspend_state < PCF50633_SS_COMPLETED_RESUME))
 		return -EBUSY;
 
 	return 0;
@@ -2428,10 +2457,10 @@ static int pcf50633_resume(struct device *dev)
 	u8 res[5];
 
 	dev_info(dev, "pcf50633_resume suspended on entry = %d\n",
-						      pcf->have_been_suspended);
+						 (int)pcf->suspend_state);
 	mutex_lock(&pcf->lock);
 
-	pcf->have_been_suspended = 2; /* resuming */
+	pcf->suspend_state = PCF50633_SS_STARTING_RESUME;
 
 	/* these guys get reset while pcf50633 is suspend state, refresh */
 
@@ -2464,7 +2493,7 @@ static int pcf50633_resume(struct device *dev)
 	if (ret)
 		dev_err(dev, "Failed to set int masks :-( %d\n", ret);
 
-	pcf->have_been_suspended = 3; /* resume completed */
+	pcf->suspend_state = PCF50633_SS_COMPLETED_RESUME;
 
 	mutex_unlock(&pcf->lock);
 
@@ -2498,6 +2527,21 @@ static struct i2c_driver pcf50633_driver = {
 	.detach_client	= pcf50633_detach_client,
 };
 
+/* we have this purely to capture an early indication that we are coming out
+ * of suspend, before our device resume got called; async interrupt service is
+ * interested in this
+ */
+
+static int pcf50633_plat_resume(struct platform_device *pdev)
+{
+	/* i2c_get_clientdata(to_i2c_client(&pdev->dev)) returns NULL at this
+	 * early resume time so we have to use pcf50633_global
+	 */
+	pcf50633_global->suspend_state = PCF50633_SS_RESUMING_BUT_NOT_US_YET;
+
+	return 0;
+}
+
 /* platform driver, since i2c devices don't have platform_data */
 static int __init pcf50633_plat_probe(struct platform_device *pdev)
 {
@@ -2519,6 +2563,7 @@ static int pcf50633_plat_remove(struct platform_device *pdev)
 static struct platform_driver pcf50633_plat_driver = {
 	.probe	= pcf50633_plat_probe,
 	.remove	= pcf50633_plat_remove,
+	.resume_early = pcf50633_plat_resume,
 	.driver = {
 		.owner	= THIS_MODULE,
 		.name 	= "pcf50633",
-- 
1.5.6.3