fbtft: add tearing signal detect
diff mbox series

Message ID 1611502537-80668-1-git-send-email-zhangxuezhi3@gmail.com
State New, archived
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Series
  • fbtft: add tearing signal detect
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Commit Message

Carlis Jan. 24, 2021, 3:35 p.m. UTC
From: "carlis.zhang_cp" <zhangxuezhi1@yulong.com>

For st7789v ic,add tearing signal detect to avoid screen tearing

Signed-off-by: carlis.zhang_cp <zhangxuezhi1@yulong.com>
---
 drivers/staging/fbtft/fb_st7789v.c | 133 ++++++++++++++++++++++++++++++++++++-
 drivers/staging/fbtft/fbtft.h      |   1 +
 2 files changed, 133 insertions(+), 1 deletion(-)

Comments

Dan Carpenter Jan. 26, 2021, 7:54 a.m. UTC | #1
On Sun, Jan 24, 2021 at 11:35:37PM +0800, Carlis wrote:
> +static irqreturn_t spi_panel_te_handler(int irq, void *data)
> +{
> +	complete(&spi_panel_te);
> +	return IRQ_HANDLED;
> +}
> +
> +static void enable_spi_panel_te_irq(struct fbtft_par *par, bool enable)

It quite confused me that enable actually disables.  I always feel like
it's clearer to write these as two separate functions.

> +{
> +	static int te_irq_count;
> +
> +	if (!par->gpio.te) {

This is always checked in the caller.  And it's when it's NULL that
means it's deliberate so don't print a message.

> +		pr_err("%s:%d,SPI panel TE GPIO not configured\n",
> +		       __func__, __LINE__);
> +		return;
> +	}
> +
> +	mutex_lock(&te_mutex);
> +
> +	if (enable) {
> +		if (++te_irq_count == 1)
> +			enable_irq(gpiod_to_irq(par->gpio.te));
> +	} else {
> +		if (--te_irq_count == 0)
> +			disable_irq(gpiod_to_irq(par->gpio.te));
> +	}
> +	mutex_unlock(&te_mutex);
> +}
> +
>  /**
>   * init_display() - initialize the display controller
>   *
> @@ -82,6 +117,28 @@ enum st7789v_command {
>   */
>  static int init_display(struct fbtft_par *par)
>  {
> +	int rc;
> +	struct device *dev = par->info->device;
> +
> +	par->gpio.te = devm_gpiod_get_index_optional(dev, "te", 0, GPIOD_IN);
> +	if (par->gpio.te) {

devm_gpiod_get_index_optional() can return NULL or error pointers.  If
it returns NULL then don't print an error message.  NULL reports are
deliberate.

	par->gpio.te = devm_gpiod_get_index_optional(dev, "te", 0, GPIOD_IN);
	if (IS_ERR(par->gpio.te)) {
		pr_err("%s:%d, TE gpio not specified\n", __func__, __LINE__);
		return PTR_ERR(par->gpio.te);
	}

	if (par->gpio.te) {


> +		init_completion(&spi_panel_te);
> +		mutex_init(&te_mutex);
> +		rc = devm_request_irq(dev,
> +				      gpiod_to_irq(par->gpio.te),
> +				     spi_panel_te_handler, IRQF_TRIGGER_RISING,
> +				     "TE_GPIO", par);
> +		if (rc) {
> +			pr_err("TE request_irq failed.\n");
> +			par->gpio.te = NULL;
> +		} else {
> +			disable_irq_nosync(gpiod_to_irq(par->gpio.te));
> +			pr_err("TE request_irq completion.\n");

Why is this printing an error message if devm_request_irq() succeeds?

> +		}
> +	} else {
> +		pr_err("%s:%d, TE gpio not specified\n",
> +		       __func__, __LINE__);
> +	}
>  	/* turn off sleep mode */
>  	write_reg(par, MIPI_DCS_EXIT_SLEEP_MODE);
>  	mdelay(120);
> @@ -137,6 +194,9 @@ static int init_display(struct fbtft_par *par)
>  	 */
>  	write_reg(par, PWCTRL1, 0xA4, 0xA1);
>  
> +    /*Tearing Effect Line On*/
> +	if (par->gpio.te)
> +		write_reg(par, 0x35, 0x00);
>  	write_reg(par, MIPI_DCS_SET_DISPLAY_ON);
>  
>  	if (HSD20_IPS)
> @@ -145,6 +205,76 @@ static int init_display(struct fbtft_par *par)
>  	return 0;
>  }
>  
> +/*****************************************************************************
> + *
> + *   int (*write_vmem)(struct fbtft_par *par);
> + *
> + *****************************************************************************/
> +
> +/* 16 bit pixel over 8-bit databus */
> +int st7789v_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
> +{
> +	u16 *vmem16;
> +	__be16 *txbuf16 = par->txbuf.buf;
> +	size_t remain;
> +	size_t to_copy;
> +	size_t tx_array_size;
> +	int i;
> +	int rc, ret = 0;

Delete one of these "rc" or "rec" variables.

> +	size_t startbyte_size = 0;
> +
> +	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "st7789v ---%s(offset=%zu, len=%zu)\n",
> +		      __func__, offset, len);
> +
> +	remain = len / 2;
> +	vmem16 = (u16 *)(par->info->screen_buffer + offset);
> +
> +	if (par->gpio.dc)
> +		gpiod_set_value(par->gpio.dc, 1);
> +
> +	/* non buffered write */
> +	if (!par->txbuf.buf)
> +		return par->fbtftops.write(par, vmem16, len);
> +
> +	/* buffered write */
> +	tx_array_size = par->txbuf.len / 2;
> +
> +	if (par->startbyte) {
> +		txbuf16 = par->txbuf.buf + 1;
> +		tx_array_size -= 2;
> +		*(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
> +		startbyte_size = 1;
> +	}
> +
> +	while (remain) {
> +		to_copy = min(tx_array_size, remain);
> +		dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
> +			to_copy, remain - to_copy);
> +
> +		for (i = 0; i < to_copy; i++)
> +			txbuf16[i] = cpu_to_be16(vmem16[i]);
> +
> +		vmem16 = vmem16 + to_copy;
> +		if (par->gpio.te) {
> +			enable_spi_panel_te_irq(par, true);
> +			reinit_completion(&spi_panel_te);
> +			rc = wait_for_completion_timeout(&spi_panel_te,
> +							 msecs_to_jiffies(SPI_PANEL_TE_TIMEOUT));
> +			if (rc == 0)
> +				pr_err("wait panel TE time out\n");
> +		}
> +		ret = par->fbtftops.write(par, par->txbuf.buf,
> +								startbyte_size + to_copy * 2);

Line break is whacky.

> +		if (par->gpio.te)
> +			enable_spi_panel_te_irq(par, false);
> +		if (ret < 0)
> +			return ret;
> +		remain -= to_copy;
> +	}
> +
> +	return ret;

Shouldn't this be "return len;" or something?

> +}
> +

regards,
dan carpenter
Carlis Jan. 26, 2021, 12:43 p.m. UTC | #2
On Tue, 26 Jan 2021 10:54:41 +0300
Dan Carpenter <dan.carpenter@oracle.com> wrote:

> On Sun, Jan 24, 2021 at 11:35:37PM +0800, Carlis wrote:
> > +static irqreturn_t spi_panel_te_handler(int irq, void *data)
> > +{
> > +	complete(&spi_panel_te);
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static void enable_spi_panel_te_irq(struct fbtft_par *par, bool
> > enable)  
> 
> It quite confused me that enable actually disables.  I always feel
> like it's clearer to write these as two separate functions.
> 
> > +{
> > +	static int te_irq_count;
> > +
> > +	if (!par->gpio.te) {  
> 
> This is always checked in the caller.  And it's when it's NULL that
> means it's deliberate so don't print a message.
> 
> > +		pr_err("%s:%d,SPI panel TE GPIO not configured\n",
> > +		       __func__, __LINE__);
> > +		return;
> > +	}
> > +
> > +	mutex_lock(&te_mutex);
> > +
> > +	if (enable) {
> > +		if (++te_irq_count == 1)
> > +			enable_irq(gpiod_to_irq(par->gpio.te));
> > +	} else {
> > +		if (--te_irq_count == 0)
> > +			disable_irq(gpiod_to_irq(par->gpio.te));
> > +	}
> > +	mutex_unlock(&te_mutex);
> > +}
> > +
> >  /**
> >   * init_display() - initialize the display controller
> >   *
> > @@ -82,6 +117,28 @@ enum st7789v_command {
> >   */
> >  static int init_display(struct fbtft_par *par)
> >  {
> > +	int rc;
> > +	struct device *dev = par->info->device;
> > +
> > +	par->gpio.te = devm_gpiod_get_index_optional(dev, "te", 0,
> > GPIOD_IN);
> > +	if (par->gpio.te) {  
> 
> devm_gpiod_get_index_optional() can return NULL or error pointers.  If
> it returns NULL then don't print an error message.  NULL reports are
> deliberate.
> 
> 	par->gpio.te = devm_gpiod_get_index_optional(dev, "te", 0,
> GPIOD_IN); if (IS_ERR(par->gpio.te)) {
> 		pr_err("%s:%d, TE gpio not specified\n", __func__,
> __LINE__); return PTR_ERR(par->gpio.te);
> 	}
> 
> 	if (par->gpio.te) {
> 
> 
> > +		init_completion(&spi_panel_te);
> > +		mutex_init(&te_mutex);
> > +		rc = devm_request_irq(dev,
> > +				      gpiod_to_irq(par->gpio.te),
> > +				     spi_panel_te_handler,
> > IRQF_TRIGGER_RISING,
> > +				     "TE_GPIO", par);
> > +		if (rc) {
> > +			pr_err("TE request_irq failed.\n");
> > +			par->gpio.te = NULL;
> > +		} else {
> > +
> > disable_irq_nosync(gpiod_to_irq(par->gpio.te));
> > +			pr_err("TE request_irq completion.\n");  
> 
> Why is this printing an error message if devm_request_irq() succeeds?
> 
> > +		}
> > +	} else {
> > +		pr_err("%s:%d, TE gpio not specified\n",
> > +		       __func__, __LINE__);
> > +	}
> >  	/* turn off sleep mode */
> >  	write_reg(par, MIPI_DCS_EXIT_SLEEP_MODE);
> >  	mdelay(120);
> > @@ -137,6 +194,9 @@ static int init_display(struct fbtft_par *par)
> >  	 */
> >  	write_reg(par, PWCTRL1, 0xA4, 0xA1);
> >  
> > +    /*Tearing Effect Line On*/
> > +	if (par->gpio.te)
> > +		write_reg(par, 0x35, 0x00);
> >  	write_reg(par, MIPI_DCS_SET_DISPLAY_ON);
> >  
> >  	if (HSD20_IPS)
> > @@ -145,6 +205,76 @@ static int init_display(struct fbtft_par *par)
> >  	return 0;
> >  }
> >  
> > +/*****************************************************************************
> > + *
> > + *   int (*write_vmem)(struct fbtft_par *par);
> > + *
> > +
> > *****************************************************************************/
> > + +/* 16 bit pixel over 8-bit databus */
> > +int st7789v_write_vmem16_bus8(struct fbtft_par *par, size_t
> > offset, size_t len) +{
> > +	u16 *vmem16;
> > +	__be16 *txbuf16 = par->txbuf.buf;
> > +	size_t remain;
> > +	size_t to_copy;
> > +	size_t tx_array_size;
> > +	int i;
> > +	int rc, ret = 0;  
> 
> Delete one of these "rc" or "rec" variables.
> 
> > +	size_t startbyte_size = 0;
> > +
> > +	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "st7789v
> > ---%s(offset=%zu, len=%zu)\n",
> > +		      __func__, offset, len);
> > +
> > +	remain = len / 2;
> > +	vmem16 = (u16 *)(par->info->screen_buffer + offset);
> > +
> > +	if (par->gpio.dc)
> > +		gpiod_set_value(par->gpio.dc, 1);
> > +
> > +	/* non buffered write */
> > +	if (!par->txbuf.buf)
> > +		return par->fbtftops.write(par, vmem16, len);
> > +
> > +	/* buffered write */
> > +	tx_array_size = par->txbuf.len / 2;
> > +
> > +	if (par->startbyte) {
> > +		txbuf16 = par->txbuf.buf + 1;
> > +		tx_array_size -= 2;
> > +		*(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
> > +		startbyte_size = 1;
> > +	}
> > +
> > +	while (remain) {
> > +		to_copy = min(tx_array_size, remain);
> > +		dev_dbg(par->info->device, "    to_copy=%zu,
> > remain=%zu\n",
> > +			to_copy, remain - to_copy);
> > +
> > +		for (i = 0; i < to_copy; i++)
> > +			txbuf16[i] = cpu_to_be16(vmem16[i]);
> > +
> > +		vmem16 = vmem16 + to_copy;
> > +		if (par->gpio.te) {
> > +			enable_spi_panel_te_irq(par, true);
> > +			reinit_completion(&spi_panel_te);
> > +			rc =
> > wait_for_completion_timeout(&spi_panel_te,
> > +
> > msecs_to_jiffies(SPI_PANEL_TE_TIMEOUT));
> > +			if (rc == 0)
> > +				pr_err("wait panel TE time out\n");
> > +		}
> > +		ret = par->fbtftops.write(par, par->txbuf.buf,
> > +
> > startbyte_size + to_copy * 2);  
> 
> Line break is whacky.
> 
> > +		if (par->gpio.te)
> > +			enable_spi_panel_te_irq(par, false);
> > +		if (ret < 0)
> > +			return ret;
> > +		remain -= to_copy;
> > +	}
> > +
> > +	return ret;  
> 
> Shouldn't this be "return len;" or something?
> 
> > +}
> > +  
> 
> regards,
> dan carpenter
> 

OK,i will fix in patch v4

regards,
zhangxuezhi

Patch
diff mbox series

diff --git a/drivers/staging/fbtft/fb_st7789v.c b/drivers/staging/fbtft/fb_st7789v.c
index 3a280cc..c687b58 100644
--- a/drivers/staging/fbtft/fb_st7789v.c
+++ b/drivers/staging/fbtft/fb_st7789v.c
@@ -9,9 +9,12 @@ 
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
 #include <linux/module.h>
 #include <video/mipi_display.h>
-
+#include <linux/gpio/consumer.h>
 #include "fbtft.h"
 
 #define DRVNAME "fb_st7789v"
@@ -66,6 +69,38 @@  enum st7789v_command {
 #define MADCTL_MX BIT(6) /* bitmask for column address order */
 #define MADCTL_MY BIT(7) /* bitmask for page address order */
 
+#define SPI_PANEL_TE_TIMEOUT	400
+static struct mutex te_mutex;/*mutex for tearing line*/
+static struct completion spi_panel_te;
+
+static irqreturn_t spi_panel_te_handler(int irq, void *data)
+{
+	complete(&spi_panel_te);
+	return IRQ_HANDLED;
+}
+
+static void enable_spi_panel_te_irq(struct fbtft_par *par, bool enable)
+{
+	static int te_irq_count;
+
+	if (!par->gpio.te) {
+		pr_err("%s:%d,SPI panel TE GPIO not configured\n",
+		       __func__, __LINE__);
+		return;
+	}
+
+	mutex_lock(&te_mutex);
+
+	if (enable) {
+		if (++te_irq_count == 1)
+			enable_irq(gpiod_to_irq(par->gpio.te));
+	} else {
+		if (--te_irq_count == 0)
+			disable_irq(gpiod_to_irq(par->gpio.te));
+	}
+	mutex_unlock(&te_mutex);
+}
+
 /**
  * init_display() - initialize the display controller
  *
@@ -82,6 +117,28 @@  enum st7789v_command {
  */
 static int init_display(struct fbtft_par *par)
 {
+	int rc;
+	struct device *dev = par->info->device;
+
+	par->gpio.te = devm_gpiod_get_index_optional(dev, "te", 0, GPIOD_IN);
+	if (par->gpio.te) {
+		init_completion(&spi_panel_te);
+		mutex_init(&te_mutex);
+		rc = devm_request_irq(dev,
+				      gpiod_to_irq(par->gpio.te),
+				     spi_panel_te_handler, IRQF_TRIGGER_RISING,
+				     "TE_GPIO", par);
+		if (rc) {
+			pr_err("TE request_irq failed.\n");
+			par->gpio.te = NULL;
+		} else {
+			disable_irq_nosync(gpiod_to_irq(par->gpio.te));
+			pr_err("TE request_irq completion.\n");
+		}
+	} else {
+		pr_err("%s:%d, TE gpio not specified\n",
+		       __func__, __LINE__);
+	}
 	/* turn off sleep mode */
 	write_reg(par, MIPI_DCS_EXIT_SLEEP_MODE);
 	mdelay(120);
@@ -137,6 +194,9 @@  static int init_display(struct fbtft_par *par)
 	 */
 	write_reg(par, PWCTRL1, 0xA4, 0xA1);
 
+    /*Tearing Effect Line On*/
+	if (par->gpio.te)
+		write_reg(par, 0x35, 0x00);
 	write_reg(par, MIPI_DCS_SET_DISPLAY_ON);
 
 	if (HSD20_IPS)
@@ -145,6 +205,76 @@  static int init_display(struct fbtft_par *par)
 	return 0;
 }
 
+/*****************************************************************************
+ *
+ *   int (*write_vmem)(struct fbtft_par *par);
+ *
+ *****************************************************************************/
+
+/* 16 bit pixel over 8-bit databus */
+int st7789v_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
+{
+	u16 *vmem16;
+	__be16 *txbuf16 = par->txbuf.buf;
+	size_t remain;
+	size_t to_copy;
+	size_t tx_array_size;
+	int i;
+	int rc, ret = 0;
+	size_t startbyte_size = 0;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "st7789v ---%s(offset=%zu, len=%zu)\n",
+		      __func__, offset, len);
+
+	remain = len / 2;
+	vmem16 = (u16 *)(par->info->screen_buffer + offset);
+
+	if (par->gpio.dc)
+		gpiod_set_value(par->gpio.dc, 1);
+
+	/* non buffered write */
+	if (!par->txbuf.buf)
+		return par->fbtftops.write(par, vmem16, len);
+
+	/* buffered write */
+	tx_array_size = par->txbuf.len / 2;
+
+	if (par->startbyte) {
+		txbuf16 = par->txbuf.buf + 1;
+		tx_array_size -= 2;
+		*(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
+		startbyte_size = 1;
+	}
+
+	while (remain) {
+		to_copy = min(tx_array_size, remain);
+		dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
+			to_copy, remain - to_copy);
+
+		for (i = 0; i < to_copy; i++)
+			txbuf16[i] = cpu_to_be16(vmem16[i]);
+
+		vmem16 = vmem16 + to_copy;
+		if (par->gpio.te) {
+			enable_spi_panel_te_irq(par, true);
+			reinit_completion(&spi_panel_te);
+			rc = wait_for_completion_timeout(&spi_panel_te,
+							 msecs_to_jiffies(SPI_PANEL_TE_TIMEOUT));
+			if (rc == 0)
+				pr_err("wait panel TE time out\n");
+		}
+		ret = par->fbtftops.write(par, par->txbuf.buf,
+								startbyte_size + to_copy * 2);
+		if (par->gpio.te)
+			enable_spi_panel_te_irq(par, false);
+		if (ret < 0)
+			return ret;
+		remain -= to_copy;
+	}
+
+	return ret;
+}
+
 /**
  * set_var() - apply LCD properties like rotation and BGR mode
  *
@@ -259,6 +389,7 @@  static int blank(struct fbtft_par *par, bool on)
 	.gamma = HSD20_IPS_GAMMA,
 	.fbtftops = {
 		.init_display = init_display,
+		.write_vmem = st7789v_write_vmem16_bus8,
 		.set_var = set_var,
 		.set_gamma = set_gamma,
 		.blank = blank,
diff --git a/drivers/staging/fbtft/fbtft.h b/drivers/staging/fbtft/fbtft.h
index 76f8c09..93bac05 100644
--- a/drivers/staging/fbtft/fbtft.h
+++ b/drivers/staging/fbtft/fbtft.h
@@ -212,6 +212,7 @@  struct fbtft_par {
 		struct gpio_desc *wr;
 		struct gpio_desc *latch;
 		struct gpio_desc *cs;
+		struct gpio_desc *te;
 		struct gpio_desc *db[16];
 		struct gpio_desc *led[16];
 		struct gpio_desc *aux[16];