From 871c0b38ef349686071b055d012bff712088aa61 Mon Sep 17 00:00:00 2001
From: Vasily Khoruzhick <anarsoul@gmail.com>
Date: Sat, 24 Oct 2009 03:05:02 -0500
Subject: Fix resume conversions

This patch fixes a bug where the TS might stop working after suspend/resume.
This patch is under upstream review and it seems it will change a lot.

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Nelson Castillo <arhuaco@freaks-unidos.net>
---
 arch/arm/plat-s3c24xx/adc.c | 46 ++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 39 insertions(+), 7 deletions(-)

diff --git a/arch/arm/plat-s3c24xx/adc.c b/arch/arm/plat-s3c24xx/adc.c
index a1dbd0ce59e..3b16670b003 100644
--- a/arch/arm/plat-s3c24xx/adc.c
+++ b/arch/arm/plat-s3c24xx/adc.c
@@ -46,6 +46,7 @@ struct s3c_adc_client {
 	int			 result;
 	unsigned char		 is_ts;
 	unsigned char		 channel;
+	unsigned int		 selected;
 
 	void	(*select_cb)(struct s3c_adc_client *c, unsigned selected);
 	void	(*convert_cb)(struct s3c_adc_client *c,
@@ -69,6 +70,8 @@ struct adc_device {
 
 static struct adc_device *adc_dev;
 
+static struct work_struct resume_work;
+
 static LIST_HEAD(adc_pending);
 
 #define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
@@ -86,7 +89,10 @@ static inline void s3c_adc_select(struct adc_device *adc,
 {
 	unsigned con = readl(adc->regs + S3C2410_ADCCON);
 
-	client->select_cb(client, 1);
+	if (!client->selected) {
+		client->selected = 1;
+		client->select_cb(client, 1);
+	}
 
 	con &= ~S3C2410_ADCCON_MUXMASK;
 	con &= ~S3C2410_ADCCON_STDBM;
@@ -110,12 +116,9 @@ static void s3c_adc_try(struct adc_device *adc)
 {
 	struct s3c_adc_client *next = adc->ts_pend;
 
-	if (!next && !list_empty(&adc_pending)) {
+	if (!next && !list_empty(&adc_pending))
 		next = list_first_entry(&adc_pending,
 					struct s3c_adc_client, pend);
-		list_del(&next->pend);
-	} else
-		adc->ts_pend = NULL;
 
 	if (next) {
 		adc_dbg(adc, "new client is %p\n", next);
@@ -278,14 +281,20 @@ static irqreturn_t s3c_adc_irq(int irq, void *pw)
 
 	if (client->nr_samples > 0) {
 		/* fire another conversion for this */
-
+		client->selected = 1;
 		client->select_cb(client, 1);
 		s3c_adc_convert(adc);
 	} else {
 		local_irq_save(flags);
-		(client->select_cb)(client, 0);
+		client->selected = 0;
+		if (!adc->cur->is_ts)
+			list_del(&adc->cur->pend);
+		else
+			adc->ts_pend = NULL;
 		adc->cur = NULL;
 
+		(client->select_cb)(client, 0);
+
 		s3c_adc_try(adc);
 		local_irq_restore(flags);
 	}
@@ -392,20 +401,43 @@ static int s3c_adc_suspend(struct platform_device *pdev, pm_message_t state)
 	writel(con, adc->regs + S3C2410_ADCCON);
 
 	clk_disable(adc->clk);
+	disable_irq(IRQ_ADC);
+	if (!list_empty(&adc_pending) || adc->ts_pend)
+		dev_info(&pdev->dev, "We still have adc clients pending\n");
 
 	return 0;
 }
 
+/* It seems this is not needed. This is under upstream review now. */
+static void adc_resume_work(struct work_struct *work)
+{
+	if (!adc_dev) /* Have no ADC here */
+		return;
+
+	if (!list_empty(&adc_pending) || adc_dev->ts_pend)
+		/* We still have adc clients pending */
+		s3c_adc_try(adc_dev);
+}
+
 static int s3c_adc_resume(struct platform_device *pdev)
 {
 	struct adc_device *adc = platform_get_drvdata(pdev);
 
+	enable_irq(IRQ_ADC);
 	clk_enable(adc->clk);
 
 	writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
 	       adc->regs + S3C2410_ADCCON);
 	writel(adc->delay, adc->regs + S3C2410_ADCDLY);
 
+	/* Schedule task if there are clients pending. */
+	if (!list_empty(&adc_pending) || adc_dev->ts_pend) {
+		INIT_WORK(&resume_work, adc_resume_work);
+		if (!schedule_work(&resume_work))
+			dev_err(&pdev->dev,
+				"Failed to schedule adc_resume work!\n");
+	}
+
 	return 0;
 }
 
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