Fixed the LCM driver state transition delay and pixel clock issue

    Space transition between sleep-in and sleep-out of at least
    120 ms as mentionned in the spec. Also, made sure the LCM
    is moved into sleep state before the pixel clock is turned off.
    To do so, I've modified glamo-fb to send FB_BLANK_POWERDOWN before
    turning off the pixel clock. Also fixed various violation of coding
    style. This patch should reduce the risk of white screen.

    Signed-off-by: Nicolas Dufresne <nicolas.dufresne@gmail.com>

1 files changed, 79 insertions, 62 deletions

diff --git a/drivers/video/display/jbt6k74.c b/drivers/video/display/jbt6k74.c
index 9add1c6bf8a..4524be34df2 100644
--- a/drivers/video/display/jbt6k74.c
+++ b/drivers/video/display/jbt6k74.c
@@ -31,6 +31,7 @@
 #include <linux/delay.h>
 #include <linux/jbt6k74.h>
 #include <linux/fb.h>
+#include <linux/time.h>
 
 enum jbt_register {
 	JBT_REG_SLEEP_IN		= 0x10,
@@ -117,12 +118,18 @@ struct jbt_info {
 	struct notifier_block fb_notif;
 	u16 tx_buf[8];
 	u16 reg_cache[0xEE];
-	int have_resumed;
+	struct timespec last_sleep;
 };
 
 #define JBT_COMMAND	0x000
 #define JBT_DATA	0x100
 
+static inline unsigned int timespec_sub_ms(struct timespec lhs,
+					struct timespec rhs)
+{
+	struct timespec ts = timespec_sub(lhs, rhs);
+	return (ts.tv_sec * MSEC_PER_SEC) + (ts.tv_nsec / NSEC_PER_MSEC);
+}
 
 static int jbt_reg_write_nodata(struct jbt_info *jbt, u8 reg)
 {
@@ -179,7 +186,7 @@ static int jbt_init_regs(struct jbt_info *jbt)
 {
 	int rc;
 
-	dev_dbg(&jbt->spi_dev->dev, "entering %cVGA mode\n", 
+	dev_dbg(&jbt->spi_dev->dev, "entering %cVGA mode\n",
 			jbt->normal_state == JBT_STATE_QVGA_NORMAL ? 'Q' : ' ');
 
 	rc = jbt_reg_write(jbt, JBT_REG_DISPLAY_MODE1, 0x01);
@@ -268,36 +275,25 @@ static int sleep_to_normal(struct jbt_info *jbt)
 {
 	int rc;
 
-	/* RGB I/F on, RAM wirte off, QVGA through, SIGCON enable */
-	rc = jbt_reg_write(jbt, JBT_REG_DISPLAY_MODE, 0x80);
-
-	/* Quad mode off */
-	rc |= jbt_reg_write(jbt, JBT_REG_QUAD_RATE, 0x00);
-
-	/* AVDD on, XVDD on */
-	rc |= jbt_reg_write(jbt, JBT_REG_POWER_ON_OFF, 0x16);
-
-	/* Output control */
-	rc |= jbt_reg_write16(jbt, JBT_REG_OUTPUT_CONTROL, 0xfff9);
+	/* Make sure we are 120 ms after SLEEP_OUT */
+	unsigned int sleep_time = timespec_sub_ms(current_kernel_time(),
+							jbt->last_sleep);
+	if (sleep_time < 120)
+		mdelay(120 - sleep_time);
 
-	/* Turn on display */
-	rc |= jbt_reg_write_nodata(jbt, JBT_REG_DISPLAY_ON);
+	if (jbt->normal_state == JBT_STATE_NORMAL) {
+		/* RGB I/F on, RAM wirte off, QVGA through, SIGCON enable */
+		rc = jbt_reg_write(jbt, JBT_REG_DISPLAY_MODE, 0x80);
 
-	/* Sleep mode off */
-	rc |= jbt_reg_write_nodata(jbt, JBT_REG_SLEEP_OUT);
-
-	return rc ? -EIO : 0;
-}
-
-static int sleep_to_qvga_normal(struct jbt_info *jbt)
-{
-	int rc;
-
-	/* RGB I/F on, RAM wirte off, QVGA through, SIGCON enable */
-	rc = jbt_reg_write(jbt, JBT_REG_DISPLAY_MODE, 0x81);
+		/* Quad mode off */
+		rc |= jbt_reg_write(jbt, JBT_REG_QUAD_RATE, 0x00);
+	} else {
+		/* RGB I/F on, RAM wirte off, QVGA through, SIGCON enable */
+		rc = jbt_reg_write(jbt, JBT_REG_DISPLAY_MODE, 0x81);
 
-	/* Quad mode on */
-	rc |= jbt_reg_write(jbt, JBT_REG_QUAD_RATE, 0x22);
+		/* Quad mode on */
+		rc |= jbt_reg_write(jbt, JBT_REG_QUAD_RATE, 0x22);
+	}
 
 	/* AVDD on, XVDD on */
 	rc |= jbt_reg_write(jbt, JBT_REG_POWER_ON_OFF, 0x16);
@@ -310,6 +306,10 @@ static int sleep_to_qvga_normal(struct jbt_info *jbt)
 
 	/* Sleep mode off */
 	rc |= jbt_reg_write_nodata(jbt, JBT_REG_SLEEP_OUT);
+	jbt->last_sleep = current_kernel_time();
+
+	/* Allow the booster and display controller to restart stably */
+	mdelay(5);
 
 	return rc ? -EIO : 0;
 }
@@ -318,9 +318,19 @@ static int normal_to_sleep(struct jbt_info *jbt)
 {
 	int rc;
 
+	/* Make sure we are 120 ms after SLEEP_OUT */
+	unsigned int sleep_time = timespec_sub_ms(current_kernel_time(),
+							jbt->last_sleep);
+	if (sleep_time < 120)
+		mdelay(120 - sleep_time);
+
 	rc = jbt_reg_write_nodata(jbt, JBT_REG_DISPLAY_OFF);
 	rc |= jbt_reg_write16(jbt, JBT_REG_OUTPUT_CONTROL, 0x8002);
 	rc |= jbt_reg_write_nodata(jbt, JBT_REG_SLEEP_IN);
+	jbt->last_sleep = current_kernel_time();
+
+	/* Allow the internal circuits to stop automatically */
+	mdelay(5);
 
 	return rc ? -EIO : 0;
 }
@@ -335,8 +345,9 @@ int jbt6k74_enter_state(struct jbt_info *jbt, enum jbt_state new_state)
 {
 	int rc = -EINVAL;
 
-	dev_dbg(&jbt->spi_dev->dev, "entering (old_state=%s, "
-		"new_state=%s)\n", jbt_state_names[jbt->state], jbt_state_names[new_state]);
+	dev_dbg(&jbt->spi_dev->dev, "entering (old_state=%s, new_state=%s)\n",
+			jbt_state_names[jbt->state],
+			jbt_state_names[new_state]);
 
 	mutex_lock(&jbt->lock);
 
@@ -363,7 +374,7 @@ int jbt6k74_enter_state(struct jbt_info *jbt, enum jbt_state new_state)
 			/* first transition into sleep */
 			rc = standby_to_sleep(jbt);
 			/* then transition into normal */
-			rc |= sleep_to_qvga_normal(jbt);
+			rc |= sleep_to_normal(jbt);
 			break;
 		}
 		break;
@@ -376,10 +387,8 @@ int jbt6k74_enter_state(struct jbt_info *jbt, enum jbt_state new_state)
 			rc = sleep_to_standby(jbt);
 			break;
 		case JBT_STATE_NORMAL:
-			rc = sleep_to_normal(jbt);
-			break;
 		case JBT_STATE_QVGA_NORMAL:
-			rc = sleep_to_qvga_normal(jbt);
+			rc = sleep_to_normal(jbt);
 			break;
 		}
 		break;
@@ -405,7 +414,7 @@ int jbt6k74_enter_state(struct jbt_info *jbt, enum jbt_state new_state)
 			/* third transition into sleep */
 			rc |= standby_to_sleep(jbt);
 			/* fourth transition into normal */
-			rc |= sleep_to_qvga_normal(jbt);
+			rc |= sleep_to_normal(jbt);
 			break;
 		}
 		break;
@@ -436,12 +445,13 @@ int jbt6k74_enter_state(struct jbt_info *jbt, enum jbt_state new_state)
 		}
 		break;
 	}
-	
+
 	if (rc == 0)
 		jbt->state = new_state;
 	else
-		dev_err(&jbt->spi_dev->dev, "Failed enter state '%s')\n", jbt_state_names[new_state]);
-	
+		dev_err(&jbt->spi_dev->dev, "Failed enter state '%s')\n",
+				jbt_state_names[new_state]);
+
 	mutex_unlock(&jbt->lock);
 
 	return rc;
@@ -525,18 +535,27 @@ static ssize_t gamma_write(struct device *dev, struct device_attribute *attr,
 static ssize_t reset_write(struct device *dev, struct device_attribute *attr,
 			   const char *buf, size_t count)
 {
+	int rc;
 	struct jbt_info *jbt = dev_get_drvdata(dev);
-	struct jbt6k74_platform_data *jbt6k74_pdata = jbt->spi_dev->dev.platform_data;
+	struct jbt6k74_platform_data *pdata = jbt->spi_dev->dev.platform_data;
 
 	dev_info(dev, "**** jbt6k74 reset\n");
 
-	jbt6k74_enter_state(jbt, JBT_STATE_DEEP_STANDBY);
+	mutex_lock(&jbt->lock);
+
+	jbt->state = JBT_STATE_DEEP_STANDBY;
 
 	/* hard reset the jbt6k74 */
-	mutex_lock(&jbt->lock);
-	(jbt6k74_pdata->reset)(0, 0);
+	(pdata->reset)(0, 0);
 	mdelay(1);
-	(jbt6k74_pdata->reset)(0, 1);
+	(pdata->reset)(0, 1);
+	mdelay(120);
+
+	rc = jbt_reg_write_nodata(jbt, 0x01);
+	if (rc < 0)
+		dev_err(&jbt->spi_dev->dev, "cannot soft reset\n");
+	mdelay(120);
+
 	mutex_unlock(&jbt->lock);
 
 	jbt6k74_enter_state(jbt, jbt->normal_state);
@@ -572,31 +591,30 @@ static int fb_notifier_callback(struct notifier_block *self,
 	struct fb_event *evdata = data;
 	int fb_blank;
 
+	jbt = container_of(self, struct jbt_info, fb_notif);
+
+	dev_dbg(&jbt->spi_dev->dev, "jbt6k74 event=%lu\n", event);
+
 	if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
 		return 0;
 
 	fb_blank = *(int *)evdata->data;
-	jbt = container_of(self, struct jbt_info, fb_notif);
-
 	switch (fb_blank) {
 	case FB_BLANK_UNBLANK:
-		dev_info(&jbt->spi_dev->dev, "**** jbt6k74 unblank\n");
+		dev_dbg(&jbt->spi_dev->dev, "unblank\n");
 		jbt6k74_enter_state(jbt, jbt->normal_state);
 		break;
 	case FB_BLANK_NORMAL:
-		dev_info(&jbt->spi_dev->dev, "**** jbt6k74 normal\n");
+		dev_dbg(&jbt->spi_dev->dev, "blank\n");
 		break;
 	case FB_BLANK_VSYNC_SUSPEND:
-		dev_info(&jbt->spi_dev->dev, "**** jbt6k74 vsync suspend\n");
+		dev_dbg(&jbt->spi_dev->dev, "vsync suspend\n");
 		break;
 	case FB_BLANK_HSYNC_SUSPEND:
-		dev_info(&jbt->spi_dev->dev, "**** jbt6k74 hsync suspend\n");
+		dev_dbg(&jbt->spi_dev->dev, "hsync suspend\n");
 		break;
 	case FB_BLANK_POWERDOWN:
-		dev_info(&jbt->spi_dev->dev, "**** jbt6k74 powerdown\n");
-		/* FIXME DEEP STANDBY wihtout suspend causes WSOD at cold
-		 * temperature on certain devices. */
-		/*jbt6k74_enter_state(jbt, JBT_STATE_DEEP_STANDBY);*/
+		dev_dbg(&jbt->spi_dev->dev, "powerdown\n");
 		jbt6k74_enter_state(jbt, JBT_STATE_SLEEP);
 		break;
 	}
@@ -610,7 +628,7 @@ static int __devinit jbt_probe(struct spi_device *spi)
 {
 	int rc;
 	struct jbt_info *jbt;
-	struct jbt6k74_platform_data *jbt6k74_pdata = spi->dev.platform_data;
+	struct jbt6k74_platform_data *pdata = spi->dev.platform_data;
 
 	/* the controller doesn't have a MISO pin; we can't do detection */
 
@@ -631,6 +649,7 @@ static int __devinit jbt_probe(struct spi_device *spi)
 	jbt->spi_dev = spi;
 	jbt->normal_state = JBT_STATE_NORMAL;
 	jbt->state = JBT_STATE_DEEP_STANDBY;
+	jbt->last_sleep = current_kernel_time();
 	mutex_init(&jbt->lock);
 
 	dev_set_drvdata(&spi->dev, jbt);
@@ -654,8 +673,8 @@ static int __devinit jbt_probe(struct spi_device *spi)
 		goto err_sysfs;
 	}
 
-	if (jbt6k74_pdata->probe_completed)
-		(jbt6k74_pdata->probe_completed)(&spi->dev);
+	if (pdata->probe_completed)
+		(pdata->probe_completed)(&spi->dev);
 
 	return 0;
 
@@ -693,8 +712,6 @@ static int jbt_suspend(struct spi_device *spi, pm_message_t state)
 
 	jbt6k74_enter_state(jbt, JBT_STATE_DEEP_STANDBY);
 
-	jbt->have_resumed = 0;
-
 	dev_info(&spi->dev, "**** jbt6k74 suspend end\n");
 
 	return 0;
@@ -703,14 +720,14 @@ static int jbt_suspend(struct spi_device *spi, pm_message_t state)
 int jbt6k74_resume(struct spi_device *spi)
 {
 	struct jbt_info *jbt = dev_get_drvdata(&spi->dev);
-	struct jbt6k74_platform_data *jbt6k74_pdata = spi->dev.platform_data;
+	struct jbt6k74_platform_data *pdata = spi->dev.platform_data;
 
 	dev_info(&spi->dev, "**** jbt6k74 resume start\n");
 
 	jbt6k74_enter_state(jbt, jbt->normal_state);
 
-	if (jbt6k74_pdata->resuming)
-		(jbt6k74_pdata->resuming)(0);
+	if (pdata->resuming)
+		(pdata->resuming)(0);
 
 	dev_info(&spi->dev, "**** jbt6k74 resume end\n");