[PATCH v6] fbtft: add tearing signal detect

Carlis
2021-01-27T07:31:16Z

From: zhangxuezhi <zhangxuezhi1@yulong.com>

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

Signed-off-by: zhangxuezhi <zhangxuezhi1@yulong.com>
---
v6: add te gpio request fail deal logic
---
drivers/staging/fbtft/fb_st7789v.c | 133 ++++++++++++++++++++++++++++++++++++-
drivers/staging/fbtft/fbtft.h | 1 +
2 files changed, 133 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/fbtft/fb_st7789v.c b/drivers/staging/fbtft/fb_st7789v.c
index 3a280cc..777391e 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 +69,32 @@ 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 set_spi_panel_te_irq_status(struct fbtft_par *par, bool enable)
+{
+ static int te_irq_count;
+
+ 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 +111,34 @@ 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 (IS_ERR(par->gpio.te)) {
+ rc = PTR_ERR(par->gpio.te);
+ pr_err("Failed to request te gpio: %d\n", rc);
+ par->gpio.te = NULL;
+ }
+ 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");
+ devm_gpiod_put(dev, par->gpio.te);
+ par->gpio.te = NULL;
+ } else {
+ disable_irq_nosync(gpiod_to_irq(par->gpio.te));
+ pr_info("TE request_irq completion.\n");
+ }
+ } else {
+ pr_info("%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 */
+static 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 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) {
+ set_spi_panel_te_irq_status(par, true);
+ reinit_completion(&spi_panel_te);
+ ret = wait_for_completion_timeout(&spi_panel_te,
+ msecs_to_jiffies(SPI_PANEL_TE_TIMEOUT));
+ if (ret == 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)
+ set_spi_panel_te_irq_status(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];
--
1.9.1