From: zhangxuezhi <zhangxuez...@yulong.com>

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

Signed-off-by: zhangxuezhi <zhangxuez...@yulong.com>
---
v7: request fail to return error value
---
 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..c964cc1 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);
+               return rc;
+       }
+       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);
+                       return rc;
+               }
+
+               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

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